[Federal Register Volume 75, Number 55 (Tuesday, March 23, 2010)]
[Proposed Rules]
[Pages 13910-14014]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-5132]
[[Page 13909]]
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Part III
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 12-Month Findings for
Petitions to List the Greater Sage-Grouse (Centrocercus urophasianus)
as Threatened or Endangered; Proposed Rule
Federal Register / Vol. 75, No. 55 / Tuesday, March 23, 2010 /
Proposed Rules
[[Page 13910]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R6-ES-2010-0018]
[MO 92210-0-0008-B2]
Endangered and Threatened Wildlife and Plants; 12-Month Findings
for Petitions to List the Greater Sage-Grouse (Centrocercus
urophasianus) as Threatened or Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition findings.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce
three 12-month findings on petitions to list three entities of the
greater sage-grouse (Centrocercus urophasianus) as threatened or
endangered under the Endangered Species Act of 1973, as amended (Act).
We find that listing the greater sage-grouse (rangewide) is warranted,
but precluded by higher priority listing actions. We will develop a
proposed rule to list the greater sage-grouse as our priorities allow.
We find that listing the western subspecies of the greater sage-
grouse is not warranted, based on determining that the western
subspecies is not a valid taxon and thus is not a listable entity under
the Act. We note, however, that greater sage-grouse in the area covered
by the putative western subspecies (except those in the Bi-State area
(Mono Basin), which are covered by a separate finding) are encompassed
by our finding that listing the species is warranted but precluded
rangewide.
We find that listing the Bi-State population (previously referred
to as the Mono Basin area population), which meets our criteria as a
distinct population segment (DPS) of the greater sage-grouse, is
warranted but precluded by higher priority listing actions. We will
develop a proposed rule to list the Bi-State DPS of the greater sage-
grouse as our priorities allow, possibly in conjunction with a proposed
rule to list the greater sage-grouse rangewide.
DATES: The finding announced in the document was made on March 23,
2010.
ADDRESSES: This finding is available on the Internet at http://www.regulations.gov and www.fws.gov. Supporting documentation we used
to prepare this finding is available for public inspection, by
appointment, during normal business hours at the U.S. Fish and Wildlife
Service, 5353 Yellowstone Road, Suite 308A, Cheyenne, Wyoming 82009;
telephone (307) 772-2374; facsimile (307) 772-2358. Please submit any
new information, materials, comments, or questions concerning this
species to the Service at the above address.
FOR FURTHER INFORMATION CONTACT: Brian T. Kelly, Field Supervisor, U.S.
Fish and Wildlife Service, Wyoming Ecological Services Office (see
ADDRESSES). If you use a telecommunications device for the deaf (TDD),
call the Federal Information Relay Service (FIRS) at (800) 877-8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.), requires
that, for any petition containing substantial scientific or commercial
information that the listing may be warranted, we make a finding within
12 months of the date of the receipt of the petition on whether the
petitioned action is (a) not warranted, (b) warranted, or (c)
warranted, but that immediate proposal of a regulation implementing the
petitioned action is precluded by other pending proposals to determine
whether species are threatened or endangered, and expeditious progress
is being made to add or remove qualified species from the Lists of
Endangered and Threatened Wildlife and Plants. Section 4(b)(3)(C) of
the Act requires that we treat a petition for which the requested
action is found to be warranted but precluded as though resubmitted on
the date of such finding; that is, requiring a subsequent finding to be
made within 12 months. We must publish these 12-month findings in the
Federal Register.
Previous Federal Action
Greater Sage-Grouse
On July 2, 2002, we received a petition from Craig C. Dremann
requesting that we list the greater sage-grouse (Centrocercus
urophasianus) as endangered across its entire range. We received a
second petition from the Institute for Wildlife Protection on March 24,
2003, requesting that the greater sage-grouse be listed rangewide. On
December 29, 2003, we received a third petition from the American Lands
Alliance and 20 additional conservation organizations (American Lands
Alliance et al.) to list the greater sage-grouse as threatened or
endangered rangewide. On April 21, 2004, we announced our 90-day
petition finding in the Federal Register (69 FR 21484) that these
petitions taken collectively, as well as information in our files,
presented substantial information indicating that the petitioned
actions may be warranted. On July 9, 2004, we published a notice to
reopen the period for submitting comments on our 90-day finding, until
July 30, 2004 (69 FR 41445). In accordance with section 4(b)(3)(A) of
the Act, we completed a status review of the best available scientific
and commercial information on the species. On January 12, 2005, we
announced our not-warranted 12-month finding in the Federal Register
(70 FR 2243).
On July 14, 2006, Western Watersheds Project filed a complaint in
Federal district court alleging that the Service's 2005 12-month
finding was incorrect and arbitrary and requested the finding be
remanded to the Service. On December 4, 2007, the U.S. District Court
of Idaho ruled that our 2005 finding was arbitrary and capricious, and
remanded it to the Service for further consideration. On January 30,
2008, the court approved a stipulated agreement between the Department
of Justice and the plaintiffs to issue a new finding in May 2009,
contingent on the availability of a new monograph of information on the
sage-grouse and its habitat (Monograph). On February 26, 2008, we
published a notice to initiate a status review for the greater sage-
grouse (73 FR 10218), and on April 29, 2008, we published a notice
extending the request for submitting information to June 27, 2008 (73
FR 23172). Publication of the Monograph was delayed due to
circumstances outside the control of the Service. An amended joint
stipulation, adopted by the court on June 15, 2009, required the
Service to submit the 12-month finding to the Federal Register by
February 26, 2010; this due date was subsequently extended to March 5,
2010.
Western Subspecies of the Greater Sage-Grouse
The western subspecies of the greater sage-grouse (Centrocercus
urophasianus phaios) was identified by the Service as a category 2
candidate species on September 18, 1985 (50 FR 37958). At the time, we
defined Category 2 species as those species for which we possessed
information indicating that a proposal to list as endangered or
threatened was possibly appropriate, but for which conclusive data on
biological vulnerability and threats were not available to support a
proposed rule. On February 28, 1996, we discontinued the designation of
category 2 species as candidates for listing under the Act (61 FR
7596), and consequently the western subspecies was no longer considered
to be a candidate for listing.
We received a petition, dated January 24, 2002, from the Institute
for Wildlife
[[Page 13911]]
Protection requesting that the western subspecies occurring from
northern California through Oregon and Washington, as well as any
western sage-grouse still occurring in parts of Idaho, be listed under
the Act. The petitioner excluded the Mono Basin area populations in
California and northwest Nevada since they already had petitioned this
population as a distinct population segment (DPS) for emergency listing
(see discussion of Bi-State area (Mono Basin) population below). The
petitioner also requested that the Service include the Columbia Basin
DPS in this petition, even though we had already identified this DPS as
a candidate for listing under the Act (66 FR 22984, May 7, 2001) (see
discussion of Columbia Basin below).
We published a 90-day finding on February 7, 2003 (68 FR 6500),
that the petition did not present substantial information indicating
the petitioned action was warranted based on our determination that
there was insufficient evidence to indicate that the petitioned western
population of sage-grouse is a valid subspecies or DPS. The petitioner
pursued legal action, first with a 60-day Notice of Intent to sue,
followed by filing a complaint in Federal district court on June 6,
2003, challenging the merits of our 90-day finding. On August 10, 2004,
the U.S. District Court for the Western District of Washington ruled in
favor of the Service (Case No. C03-1251P). The petitioner appealed and
on March 3, 2006, the U.S. Court of Appeals for the Ninth Circuit
reversed in part the ruling of the District Court and remanded the
matter for a new 90-day finding (Institute for Wildlife Protection v.
Norton, 2006 U.S. App. LEXIS 5428 9th Cir., March 3, 2006).
Specifically, the Court of Appeals rejected the Service's conclusion
that the petition did not present substantial information indicating
that western sage-grouse may be a valid subspecies, but upheld the
Service's determination that the petition did not present substantial
information indicating that the petitioned population may constitute a
DPS. The Court's primary concern was that the Service did not provide a
sufficient description of the principles we employed to determine the
validity of the subspecies classification. On April 29, 2008, we
published in the Federal Register (73 FR 23170) a 90-day finding that
the petition presented substantial scientific or commercial information
indicating that listing western sage-grouse may be warranted and
initiated a status review for western sage-grouse.
In a related action, the Service also has made a finding on a
petition to list the eastern subspecies of the greater sage-grouse
(Centrocercus urophasianus urophasianus). On July 3, 2002, we received
a petition from the Institute for Wildlife Protection to list the
eastern subspecies, identified in the petition as including all sage-
grouse east of Oregon, Washington, northern California, and a small
portion of Idaho. The petitioners sued the Service in U.S. District
Court on January 10, 2003, for failure to complete a 90-day finding. On
October 3, 2003, the Court ordered the Service to complete a finding.
The Service published its not-substantial 90-day finding in the Federal
Register on January 7, 2004 (69 FR 933), based on our determination
that the eastern sage-grouse was not a valid subspecies. The not-
substantial finding was challenged, and on September 28, 2004, the U.S.
District Court ruled in favor of the Service, dismissing the
plaintiff's case.
Columbia Basin (Washington) Population of the Western Subspecies
On May 28, 1999, we received a petition dated May 14, 1999, from
the Northwest Ecosystem Alliance and the Biodiversity Legal Foundation.
The petitioners requested that the Washington population of western
sage-grouse (C. u. phaios) be listed as threatened or endangered under
the Act. The petitioners requested listing of the Washington population
of western sage-grouse based upon threats to the population and its
isolation from the remainder of the taxon. Accompanying the petition
was information relating to the taxonomy, ecology, threats, and the
past and present distribution of western sage-grouse.
In our documents we have used ``Columbia Basin population'' rather
than ``Washington population'' because we believe it more appropriately
describes the petitioned entity. We published a substantial 90-day
finding on August 24, 2000 (65 FR 51578). On May 7, 2001, we published
our 12-month finding (66 FR 22984), which included our determination
that the Columbia Basin population of the western sage-grouse met the
requirements of our policy on DPSs (61 FR 4722) and that listing the
DPS was warranted but precluded by other higher priority listing
actions. As required by section 4(b)(3)(C) of the Act, we have
subsequently made resubmitted petition findings, announced in
conjunction with our Candidate Notices of Review, in which we continued
to find that listing the Columbia Basin DPS of the western subspecies
was warranted but precluded by other higher priority listing actions
(66 FR 54811, 67 FR 40663, 69 FR 24887, 70 FR 24893, 74 FR 57803).
Subsequent to the March 2006 decision by the court on our 90-day
finding on the petition to list the western subspecies of the greater
sage-grouse (described above), our resubmitted petition findings stated
we were not updating our analysis for the DPS, but would publish an
updated finding regarding the petition to list the Columbia Basin
population of the western subspecies following completion of the new
rangewide status review for the greater sage-grouse.
Bi-State Area (Mono Basin) Population of Sage-grouse
On January 2, 2002, we received a petition from the Institute for
Wildlife Protection requesting that the sage-grouse occurring in the
Mono Basin area of Mono County, California, and Lyon County, Nevada, be
emergency listed as an endangered distinct population segment (DPS) of
Centrocercus urophasianus phaios, which the petitioners considered to
be the western subspecies of the greater sage-grouse. This request was
for portions of Alpine and Inyo Counties and most of Mono County in
California and portions of Carson City, Douglas, Esmeralda, Lyon, and
Mineral Counties in Nevada. On December 26, 2002, we published a 90-day
finding that the petition did not present substantial scientific or
commercial information indicating that the petitioned action may be
warranted (67 FR 78811). Our 2002 finding was based on our
determination that the petition did not present substantial information
indicating that the population of greater sage-grouse in this area was
a DPS under our DPS policy (61 FR 4722; February 7, 1996), and thus was
not a listable entity (67 FR 78811; December 26, 2002). Our 2002
finding also included a determination that the petition did not present
substantial information regarding threats to indicate that listing the
petitioned population may be warranted (67 FR 78811).
On November 15, 2005, we received a petition submitted by the
Stanford Law School Environmental Law Clinic on behalf of the Sagebrush
Sea Campaign, Western Watersheds Project, Center for Biological
Diversity, and Christians Caring for Creation to list the Mono Basin
area population of greater sage-grouse as a threatened or endangered
DPS of the greater sage-grouse (C. urophasianus) under the Act. On
March 28, 2006, we responded that emergency listing was not warranted
and, due to court orders and settlement agreements for other listing
actions, we would not be able to address the petition at that time.
[[Page 13912]]
On November 18, 2005, the Institute for Wildlife Protection and Dr.
Steven G. Herman sued the Service in U.S. District Court for the
Western District of Washington (Institute for Wildlife Protection et
al. v. Norton et al., No. C05-1939 RSM), challenging the Service's 2002
finding that their petition did not present substantial information
indicating that the petitioned action may be warranted. On April 11,
2006, we reached a stipulated settlement agreement with both plaintiffs
under which we agreed to evaluate the November 2005 petition and
concurrently reevaluate the December 2001 petition (received in January
2002). The settlement agreement required the Service to submit to the
Federal Register a 90-day finding by December 8, 2006, and if
substantial, to complete the 12-month finding by December 10, 2007. On
December 19, 2006, we published a 90-day finding that these petitions
did not present substantial scientific or commercial information
indicating that the petitioned actions may be warranted (71 FR 76058).
On August 23, 2007, the November 2005 petitioners filed a complaint
challenging the Service's 2006 finding. After review of the complaint,
the Service determined that we would revisit our 2006 finding. The
Service entered into a settlement agreement with the petitioners on
February 25, 2008, in which the Service agreed to a voluntary remand of
the 2006 petition finding, and to submit for publication in the Federal
Register a new 90-day finding by April 25, 2008. The agreement further
stipulated that if the new 90-day finding was positive, the Service
would undertake a status review of the Mono Basin area population of
the greater sage-grouse and submit for publication in the Federal
Register a 12-month finding by April 24, 2009.
On April 29, 2008, we published in the Federal Register (73 FR
23173) a 90-day petition finding that the petitions presented
substantial scientific or commercial information indicating that
listing the Mono Basin area population may be warranted and initiated a
status review. Based on a joint stipulation by the Service and the
plaintiffs to extend the due date for the 12-month finding, on April
23, 2009, the U.S. District Court, Northern District of California,
issued an order that if the parties did not agree to a later
alternative date, the Service would submit a 12-month finding for the
Mono Basin population of the greater sage-grouse to the Federal
Register no later than May 26, 2009. On May 27, 2009, the U.S. District
Court, Northern District of California, issued an order accepting a
joint stipulation between the Department of Justice and the plaintiffs,
which states that the parties agree that the Service may submit to the
Federal Register a single document containing the 12-month findings for
the Mono Basin area population and the greater sage-grouse no later
than by February 26, 2010. Subsequently, the due date for submission of
the document to the Federal Register was extended to March 5, 2010.
Both the November 2005 and the December 2001 petitions as well as
our 2002 and 2006 findings use the term ``Mono Basin area'' to refer to
greater sage-grouse that occur within the geographic area of eastern
California and western Nevada that includes Mono Lake. For conservation
planning purposes, this same geographic area is referred to as the Bi-
State area by the States of California and Nevada (Greater Sage-grouse
Conservation Plan for Nevada and Eastern California, 2004, pp. 4-5).
For consistency with ongoing planning efforts, we will adopt the ``Bi-
State'' nomenclature hereafter in this finding.
Biology and Ecology of Greater Sage-Grouse
Greater Sage-Grouse Description
The greater sage-grouse (Centrocercus urophasianus) is the largest
North American grouse species. Adult male greater sage-grouse range in
length from 66 to 76 centimeters (cm) (26 to 30 inches (in.)) and weigh
between 2 and 3 kilograms (kg) (4 and 7 pounds (lb)). Adult females are
smaller, ranging in length from 48 to 58 cm (19 to 23 in.) and weighing
between 1 and 2 kg (2 and 4 lb). Males and females have dark grayish-
brown body plumage with many small gray and white speckles, fleshy
yellow combs over the eyes, long pointed tails, and dark green toes.
Males also have blackish chin and throat feathers, conspicuous
phylloplumes (specialized erectile feathers) at the back of the head
and neck, and white feathers forming a ruff around the neck and upper
belly. During breeding displays, males exhibit olive-green apteria
(fleshy bare patches of skin) on their breasts (Schroeder et al. 1999,
p. 2).
Taxonomy
Greater sage-grouse are members of the Phasianidae family. They are
one of two congeneric species; the other species in the genus is the
Gunnison sage-grouse (Centrocercus minimus). In 1957, the American
Ornithologists' Union (AOU) (AOU 1957, p 139) recognized two subspecies
of the greater sage-grouse, the eastern (Centrocercus urophasianus
urophasianus) and western (C. u. phaios) based on information from
Aldrich (1946, p. 129). The original subspecies designation of the
western sage-grouse was based solely on differences in coloration
(specifically, reduced white markings and darker feathering on western
birds) among 11 museum specimens collected from 8 locations in
Washington, Oregon, and California. The last edition of the AOU Check-
list of North American Birds to include subspecies was the 5\th\
Edition, published in 1957. Subsequent editions of the Check-list have
excluded treatment of subspecies. Richard Banks, who was the AOU Chair
of the Committee on Classification and Nomenclature in 2000, indicated
that, because the AOU has not published a revised edition at the
subspecies level since 1957, the subspecies in that edition, including
the western sage-grouse, are still recognized (Banks 2000, pers.
comm.). However, in the latest edition of the Check-list (7\th\ Ed.,
1998, p. xii), the AOU explained that its decision to omit subspecies,
``carries with it our realization that an uncertain number of currently
recognized subspecies, especially those formally named early in this
century, probably cannot be validated by rigorous modern techniques.''
Since the publication of the 1957 Check-list, the validity of the
subspecies designations for greater sage-grouse has been questioned,
and in some cases dismissed, by several credible taxonomic authorities
(Johnsgard 1983, p. 109; Drut 1994, p. 2; Schroeder et al. 1999, p. 3;
International Union for Conservation of Nature (IUCN) 2000, p. 62;
Banks 2000, 2002 pers. comm.; Johnsgard 2002, p. 108; Benedict et al.
2003, p. 301). The Western Association of Fish and Wildlife Agencies
(WAFWA), an organization of 23 State and provincial agencies charged
with the protection and management of fish and wildlife resources in
the western part of the United States and Canada, also questioned the
validity of the western sage-grouse as a subspecies in its Conservation
Assessment of Greater Sage-grouse and Sagebrush Habitats (Connelly et
al. 2004, pp. 8-4 to 8-5). Furthermore, in its State conservation
assessment and strategy for greater sage-grouse, the Oregon Department
of Fish and Wildlife (ODFW) stated that ``recent genetic analysis
(Benedict et al. 2003) found little evidence to support this subspecies
distinction, and this Plan refers to sage-grouse without reference to
subspecies delineation in this document'' (Hagen 2005, p. 5).
[[Page 13913]]
The Integrated Taxonomic Information System (ITIS), a database
representing a partnership of U.S., Canadian, and Mexican agencies,
other organizations, and taxonomic specialists designed to provide
scientifically credible taxonomic information, lists the taxonomic
status of western sage-grouse as ``invalid - junior synonym'' (ITIS
2010). In an evaluation of the historical classification of the western
sage-grouse as a subspecies, Banks stated that it was ``weakly
characterized'' but felt that it would be wise to continue to regard
western sage-grouse as taxonomically valid ``for management purposes''
(Banks, pers. comm. 2000). This statement was made prior to the
availability of behavioral and genetic information that has become
available since 2000. In addition, Banks' opinion is qualified by the
phrase ``for Management purposes.'' Management recommendations and
other considerations must be clearly distinguished from scientific or
commercial data that indicate whether an entity may be taxonomically
valid for the purpose of listing under the Act.
Although the Service had referred to the western sage-grouse in
past decisions (for example, in the 12-month finding for a petition to
list the Columbia Basin population of western sage-grouse, 66 FR 22984;
May 7, 2001), this taxonomic reference was ancillary to the decision at
hand and was not the focal point of the listing action. In other words,
when past listing actions were focused on some other entity, such as a
potential distinct population segment in the State of Washington, we
accepted the published taxonomy for western sage-grouse because that
taxonomy itself was not the subject of the review and thus not subject
to more rigorous evaluation at the time.
Taxonomy is a component of the biological sciences. Therefore, in
our evaluation of the reliability of the information, we considered
scientists with appropriate taxonomic credentials (which may include a
combination of education, training, research, publications,
classification and/or other experience relevant to taxonomy) as
qualified to provide informed opinions regarding taxonomy, make
taxonomic distinctions, and/or question taxonomic classification.
There is no universally accepted definition of what constitutes a
subspecies, and the use of subspecies may vary between taxonomic groups
(Haig et al. 2006, pp. 1584-1594). The Service acknowledges the diverse
opinions of the scientific community about species and subspecies
concepts. However, to be operationally useful, subspecies must be
discernible from one another (i.e., diagnosable); this element of
``diagnosability,'' or the ability to consistently distinguish between
populations, is a common thread that runs through all subspecies
concepts. The AOU Committee on Classification and Nomenclature offers
the following definition of a subspecies: ``Subspecies should represent
geographically discrete breeding populations that are diagnosable from
other populations on the basis of plumage and/or measurements, but are
not yet reproductively isolated. Varying levels of diagnosability have
been proposed for subspecies, typically ranging from at least 75% to
95% * * * subspecies that are phenotypically but not genetically
distinct still warrant recognition if individuals can be assigned to a
subspecies with a high degree of certainty'' (AOU 2010). In addition,
the latest AOU Check-list of North American Birds describes subspecies
as: ``geographic segments of species' populations that differ abruptly
and discretely in morphology or coloration; these differences often
correspond with difference in behavior and habitat'' (AOU 1998, p.
xii).
In general, higher levels of confidence in the classification of
subspecies may be gained through the concurrence of multiple
morphological, molecular, ecological, behavioral, and/or physiological
characters (Haig et al. 2006, p. 1591). The AOU definition of
subspecies also incorporates this concept of looking for multiple lines
of evidence, in referring to abrupt and discrete differences in
morphology, coloration, and often corresponding differences in behavior
or habitat as well (AOU 1998, p. xii). To assess subspecies
diagnosability, we evaluated all the best scientific and commercial
information available to determine whether the evidence points to a
consistent separation of birds currently purported to be ``western
sage-grouse'' from other populations of greater sage-grouse. This
evaluation incorporated information that has become available since the
AOU's last subspecies review in 1957, and included data on the
geographic separation of the putative eastern and western subspecies,
behavior, morphology, and genetics. If the assessment of these multiple
characters provided a clear and consistent separation of the putative
western subspecies from other populations of sage-grouse, such that any
individual bird from the range of the western sage-grouse would likely
be correctly assigned to that subspecies on the basis of the suite of
characteristics analyzed, that would be considered indicative of a
likely valid subspecies.
Geography
The delineation between eastern and western subspecies is vaguely
defined and has changed over time from its original description
(Aldrich 1946, p. 129; Aldrich and Duvall 1955 p. 12; AOU 1957, p. 139;
Aldrich 1963, pp. 539-541). The boundary between the subspecies is
generally described along a line starting on the Oregon-Nevada border
south of Hart Mountain National Wildlife Refuge and ending near Nyssa,
Oregon (Aldrich and Duvall 1955, p. 12; Aldrich 1963, pp. 539-541).
Aldrich described the original eastern and western ranges in 1946
(Aldrich 1946, p. 129), while Aldrich and Duvall (1955, p. 12) and
Aldrich (1963, pp. 539-541) described an intermediate form in northern
California, presumably in a zone of intergradation between the
subspecies. All of Aldrich's citations include a portion of Idaho
within the western subspecies' range, but the 1957 AOU designation
included Idaho as part of the eastern subspecies (AOU 1957, p. 139).
Our evaluation reveals that a boundary between potential western
and eastern subspecies may be drawn multiple ways depending on whether
one uses general description of historical placement, by considering
topographic features, or in response to the differing patterns reported
in studying sage-grouse genetics, morphology, or behavior. In their
description of greater sage-grouse distribution, Schroeder et al.
(2004, p. 369) noted the lack of evidence for differentiating between
the purported subspecies, stating ``We did not quantify the respective
distributions of the eastern and western subspecies because of the lack
of a clear dividing line (Aldrich and Duvall 1955) and the lack of
genetic differentiation (Benedict et al. 2003).'' Based on this
information, there does not appear to be any clear and consistent
geographic separation between sage-grouse historically described as
``eastern'' and ``western.''
Morphology
As noted above, the original description of the western subspecies
of sage-grouse was based solely on differences in coloration
(specifically, reduced white markings and darker feathering on western
birds) among 11 museum specimens (10 whole birds, 1 head only)
collected from 8 locations in Washington, Oregon, and California
(Aldrich 1946, p. 129). By today's standards, this represents an
extremely small sample size that would likely
[[Page 13914]]
yield little confidence in the ability to discriminate between
populations on the basis of this character. Furthermore, the subspecies
designation was based on this single characteristic; no other
differences between the western and eastern subspecies of sage-grouse
were noted in Aldrich's original description (Aldrich 1946, p. 129;
USFWS 2010). Banks (1992) noted plumage color variation in the original
specimens Aldrich (1946) used to make his subspecies designation, and
agreed that the specimens from Washington, Oregon, and northern
California did appear darker than the specimens collected in the
eastern portion of the range. However, individual morphological
variation in greater sage-grouse, such as plumage coloration, is
extensive (Banks 1992). Further, given current taxonomic concepts,
Banks (1992) doubted that most current taxonomists would identify a
subspecies based on minor color variations from a limited number of
specimens, as were available to Aldrich during the mid-1900s (Aldrich
1946, p. 129; Aldrich and Duvall 1955, p. 12; Aldrich 1963, pp. 539-
541). Finally, the AOU Committee on Classification has stated that,
because of discoloration resulting from age and poor specimen
preparation, museum specimens ``nearly always must be supplemented by
new material for comprehensive systematic studies.'' (AOU, Check-list
of North American Birds, 7\th\ ed., 1998, p. xv.)
Schroeder (2008, pp. 1-19) examined previously collected
morphological data across the species' range from both published and
unpublished sources. He found statistically significant differences
between sexes, age groups, and populations in numerous characteristics
including body mass, wing length, tail length, and primary feather
length. Many of these differences were associated with sex and age, but
body mass also varied by season. There also were substantial
morphometric (size and shape) differences among populations. Notably,
however, these population differences were not consistent with any of
the described geographic delineations between eastern and western
subspecies. For example, sage-grouse from Washington and from Northern
Colorado up to Alberta appeared to be larger than those in Idaho,
Nevada, Oregon, and California (Schroeder 2008, p. 9). This regional
variation was not consistent with differences in previously established
genetic characteristics (Oyler-McCance et al. 2005, as cited in
Schroeder 2008, p. 9). Thus our review revealed no clear basis for
differentiating between the two described subspecies based on plumage
or morphology.
Behavior
The only data available with respect to behavior are for strutting
behavior on leks, a key component of mate selection. One recent study
compared the male strut behavior between three sage-grouse populations
that happen to include populations from both sides of the putative
eastern-western line (Taylor and Young 2006, pp. 36-41). However, the
classification of these populations changes depending on the
description of western sage-grouse used. The Lyon/Mono population falls
within the intermediate zone identified by Aldrich and Duvall (1955, p.
12) but would be classified as eastern under Aldrich (1963, p. 541).
The Lassen population may be considered either western (Aldrich 1946,
p. 129) or intermediate (Aldrich and Duvall 1955, p. 12; Aldrich 1963,
p. 541). The Nye population falls within the range of the eastern sage-
grouse (Aldrich and Duvall 1955, p. 12; Aldrich 1963, p. 541). The
researchers found that male strut rates were not significantly
different between populations, but that acoustic components of the
display for the Lyon/Mono and Lassen populations (considered
intermediate and/or western) were similar to each other, whereas the
Nye population (eastern) was distinct. We consider these results
inconclusive in distinguishing between eastern and western subspecies
because of the inconsistent results and limited geographic scope of the
study.
Schroeder (2008, p. 9) also examined previously collected data on
strutting behavior on leks, including Taylor and Young (2006). He noted
that, although there was regional variation in the strut rate of sage-
grouse, it was not clear if this variation reflected population-level
effects or some other unexplained variation. Based on the above limited
information, we do not consider there to be any strong evidence of a
clear separation of the western sage-grouse from other populations on
the basis of behavioral differences.
Genetics
Genetic research can sometimes augment or refine taxonomic
definitions that are based on morphology or behavior or both (discussed
in Haig et al. 2006, p. 1586; Oyler-McCance and Quinn in press, p. 19).
Benedict et al. (2003, p. 309) found no genetic data supporting a
subspecies designation. To investigate taxonomic questions and examine
levels of gene flow and connectedness among populations, Oyler-McCance
et al. (2005, p. 1294) conducted a comprehensive examination of the
distribution of genetic variation across the entire range of greater
sage-grouse, using both mitochondrial and nuclear deoxyribonucleic acid
(DNA) sequence data. Oyler-McCance et al. (2005, p. 1306) found that
the overall distribution of genetic variation showed a gradual shift
across the range in both mitochondrial and nuclear DNA data sets. Their
results demonstrate that greater sage-grouse populations follow an
isolation-by-distance model of restricted gene flow (gene flow
resulting from movement between neighboring populations rather than
being the result of long distance movements of individuals) (Oyler-
McCance et al. 2005, p. 1293; Campton 2007, p. 4), and are not
consistent with subspecies designations. Oyler-McCance and Quinn (in
press, entire) reviewed available studies that used molecular genetic
approaches, including Oyler-McCance et al. (2005). They examined the
genetic data bearing on the delineation of the western and eastern
subspecies of greater sage-grouse, and determined that the distinction
is not supported by the genetic data (Oyler-McCance and Quinn in press,
p. 4). The best available genetic information thus does not support the
recognition of the western sage-grouse as a separate subspecies.
Summary: Taxonomic Evaluation of the Subspecies
The AOU has not revisited the question of whether the eastern and
western subspecies are valid since their original classification in
1957. We have examined the best scientific information available
regarding the putative subspecies of the greater sage-grouse and have
considered multiple lines of evidence for the potential existence of
western and eastern subspecies based on geographic, morphological,
behavioral, and genetic data. In our evaluation, we looked for any
consistent significant differences in these characters that might
support recognition of the western or eastern sage-grouse as clear,
discrete, and diagnosable populations, such that either might be
considered a subspecies.
As described above, the boundaries distinguishing the two putative
subspecies have shifted over time, and there does not appear to be any
clear and consistent geographic separation between sage-grouse
historically described as ``eastern'' and ``western.'' Banks (1992) and
Schroeder (2008, p. 9) both found morphological variations between
individuals and populations, but Banks stated that the differences
would not be sufficient to recognize
[[Page 13915]]
subspecies by current taxonomic standards, and Schroeder noted that the
differences were not consistent with any of the described geographic or
genetic delineations between putative subspecies. Schroeder (2008 p. 9)
also noted regional behavior differences in strut rate, but stated it
was not clear if this variation reflected population-level effects.
Finally, the best available genetic information indicates there is no
distinction between the putative western and eastern subspecies
(Benedict et al. 2003, p. 309; Oyler-McCance and Quinn in press, p.
12).
Because the best scientific and commercial information do not
support the taxonomic validity of the purported eastern or western
subspecies, our analysis of the status of the greater sage-grouse
(below) does not address considerations at the scale of subspecies.
(See Findings section, below, for our finding on the petition to list
the western subspecies of the greater sage-grouse.)
Life History Characteristics
Greater sage-grouse depend on a variety of shrub-steppe habitats
throughout their life cycle, and are considered obligate users of
several species of sagebrush (e.g., Artemisia tridentata ssp.
wyomingensis (Wyoming big sagebrush), A. t. ssp. vaseyana (mountain big
sagebrush), and A. t. tridentata (basin big sagebrush)) (Patterson
1952, p. 48; Braun et al. 1976, p. 168; Connelly et al. 2000a, pp. 970-
972; Connelly et al. 2004, p. 4-1; Miller et al. in press, p. 1).
Greater sage-grouse also use other sagebrush species such as A.
arbuscula (low sagebrush), A. nova (black sagebrush), A. frigida
(fringed sagebrush), and A. cana silver sagebrush (Schroeder et al.
1999, pp. 4-5; Connelly et al. 2004, p. 3-4). Thus, sage-grouse
distribution is strongly correlated with the distribution of sagebrush
habitats (Schroeder et al. 2004, p. 364). Sage-grouse exhibit strong
site fidelity (loyalty to a particular area even when the area is no
longer of value) to seasonal habitats, which includes breeding,
nesting, brood rearing, and wintering areas (Connelly et al. 2004, p.
3-1). Adult sage-grouse rarely switch between these habitats once they
have been selected, limiting their adaptability to changes.
During the spring breeding season, male sage-grouse gather together
to perform courtship displays on areas called leks. Areas of bare soil,
short-grass steppe, windswept ridges, exposed knolls, or other
relatively open sites typically serve as leks (Patterson 1952, p. 83;
Connelly et al. 2004, p. 3-7 and references therein). Leks are often
surrounded by denser shrub-steppe cover, which is used for escape,
thermal, and feeding cover. The proximity, configuration, and abundance
of nesting habitat are key factors influencing lek location (Connelly
et al., 1981, and Connelly et al., 2000 b, cited in Connelly et al., in
press a, p. 11). Leks can be formed opportunistically at any
appropriate site within or adjacent to nesting habitat (Connelly et al.
2000a, p. 970), and, therefore, lek habitat availability is not
considered to be a limiting factor for sage-grouse (Schroeder 1999, p.
4). Nest sites are selected independent of lek locations, but the
reverse is not true (Bradbury et al. 1989, p. 22; Wakkinen et al. 1992,
p. 382). Thus, leks are indicative of nesting habitat.
Leks range in size from less than 0.04 hectare (ha) (0.1 acre (ac))
to over 36 ha (90 ac) (Connelly et al. 2004, p. 4-3) and can host from
several to hundreds of males (Johnsgard 2002, p. 112). Males defend
individual territories within leks and perform elaborate displays with
their specialized plumage and vocalizations to attract females for
mating. Although males are capable of breeding the first spring after
hatch, young males are rarely successful in breeding on leks due to the
dominance of older males (Schroeder et al. 1999, p. 14). Numerous
researchers have observed that a relatively small number of dominant
males account for the majority of copulations on each lek (Schroeder et
al. 1999, p. 8). However, Bush (2009, p. 106) found on average that
45.9 percent (range 14.3 to 54.5 percent) of genetically identified
males in a population fathered offspring in a given year, which
indicates that males and females likely engage in off-lek copulations.
Males do not participate in incubation of eggs or rearing chicks.
Females have been documented to travel more than 20 km (12.5 mi) to
their nest site after mating (Connelly et al. 2000a, p. 970), but
distances between a nest site and the lek on which breeding occurred is
variable (Connelly et al. 2004, pp. 4-5). Average distance between a
female's nest and the lek on which she was first observed ranged from
3.4 km (2.1 mi) to 7.8 km (4.8 mi) in five studies examining 301 nest
locations (Schroeder et al. 1999 p. 12).
Productive nesting areas are typically characterized by sagebrush
with an understory of native grasses and forbs, with horizontal and
vertical structural diversity that provides an insect prey base,
herbaceous forage for pre-laying and nesting hens, and cover for the
hen while she is incubating (Gregg 1991, p. 19; Schroeder et al. 1999,
p. 4; Connelly et al. 2000a, p. 971; Connelly et al. 2004, pp. 4-17,
18; Connelly et al. in press b, p. 12). Sage-grouse also may use other
shrub or bunchgrass species for nest sites (Klebenow 1969, p. 649;
Connelly et al. 2000a, p. 970; Connelly et al. 2004, p. 4-4). Shrub
canopy and grass cover provide concealment for sage-grouse nests and
young, and are critical for reproductive success (Barnett and Crawford
1994, p. 116; Gregg et al. 1994, p. 164; DeLong et al.1995, p. 90;
Connelly et al. 2004, p. 4-4). Published vegetation characteristics of
successful nest sites included a sagebrush canopy cover of 15-25
percent, sagebrush heights of 30 to 80 cm (11.8 to 31.5 in.), and
grass/forb cover of 18 cm (7.1 in.) (Connelly et al. 2000a, p. 977).
Sage-grouse clutch size ranges from 6 to 9 eggs with an average of
7 eggs (Connelly et al. in press a, pp. 14-15). The likelihood of a
female nesting in a given year averages 82 percent in eastern areas of
the range (Alberta, Montana, North Dakota, South Dakota, Colorado,
Wyoming) and 78 percent in western areas of the range (California,
Nevada, Idaho, Oregon, Washington, Utah ) (Connelly et al. in press a,
p. 15). Adult females have higher nest initiation rates than yearling
females (Connelly et al. in press a, p. 15). Nest success (one or more
eggs hatching from a nest), as reported in the scientific literature,
varies widely (15-86 percent Schroeder et al. 1999, p. 11). Overall,
the average nest success for sage-grouse in habitats where sagebrush
has not been disturbed is 51 percent and for sage-grouse in disturbed
habitats is 37 percent (Connelly et al., in press a, p. 1). Re-nesting
only occurs if the original nest is lost (Schroeder et al. 1999, p.
11). Sage-grouse re-nesting rates average 28.9 percent (based on 9
different studies) with a range from 5 to 41 percent (Connelly et al.
2004. p. 3-11). Other game bird species have much higher re-nesting
rates, often exceeding 75 percent. The impact of re-nesting on annual
productivity for most sage-grouse populations is unclear and thought to
be limited (Crawford et al. 2004, p. 4). In north-central Washington
State, re-nesting contributed to 38 percent of the annual productivity
of that population (Schroeder 1997, p. 937). However, the author
postulated that the re-nesting efforts in this population may be
greater than anywhere else in the species' range because environmental
conditions allow a longer period of time to successfully rear a clutch
(Schroeder 1997, p. 939).
Little information is available on the level of productivity
(number of chicks per hen that survive to fall) that is necessary to
maintain a stable population (Connelly et al. 2000b, p.
[[Page 13916]]
970). However, Connelly et al. (2000b, p. 970, and references therein)
suggest that 2.25 chicks per hen are necessary to maintain stable to
increasing populations. Long-term productivity estimates of 1.40-2.96
chicks per hen across the species range have been reported (Connelly
and Braun 1997, p. 20). Productivity declined slightly after 1985 to
1.21-2.19 chicks per hen (Connelly and Braun 1997, p. 20). Despite
average clutch sizes of 7 eggs (Connelly et al. in press a, p. 15) due
to low chick survival and limited renesting, there is little evidence
that populations of sage-grouse produce large annual surpluses
(Connelly et al. in press a, p. 24).
Hens rear their broods in the vicinity of the nest site for the
first 2-3 weeks following hatching (within 0.2-5 km (0.1-3.1 mi)),
based on two studies in Wyoming (Connelly et al. 2004, p. 4-8). Forbs
and insects are essential nutritional components for chicks (Klebenow
and Gray 1968, p. 81; Johnson and Boyce 1991, p. 90; Connelly et al.
2004, p. 4-9). Therefore, early brood-rearing habitat must provide
adequate cover (sagebrush canopy cover of 10 to 25 percent; Connelly et
al. 2000a, p. 977) adjacent to areas rich in forbs and insects to
ensure chick survival during this period (Connelly et al. 2004, p. 4-
9).
All sage-grouse gradually move from sagebrush uplands to more mesic
areas (moist areas such as streambeds or wet meadows) during the late
brood-rearing period (3 weeks post-hatch) in response to summer
desiccation of herbaceous vegetation (Connelly et al. 2000a, p. 971).
Summer use areas can include sagebrush habitats as well as riparian
areas, wet meadows, and alfalfa fields (Schroeder et al. 1999, p. 4).
These areas provide an abundance of forbs and insects for both hens and
chicks (Schroeder et al. 1999, p. 4; Connelly et al. 2000a, p. 971).
Sage-grouse will use free water although they do not require it since
they obtain their water needs from the food they eat. However, natural
water bodies and reservoirs can provide mesic areas for succulent forb
and insect production, thereby attracting sage-grouse hens with broods
(Connelly et al. 2004, p. 4-12). Broodless hens and cocks also will use
more mesic areas in close proximity to sagebrush cover during the late
summer, often arriving before hens with broods (Connelly et al. 2004,
p. 4-10).
As vegetation continues to desiccate through the late summer and
fall, sage-grouse shift their diet entirely to sagebrush (Schroeder et
al. 1999, p. 5). Sage-grouse depend entirely on sagebrush throughout
the winter for both food and cover. Sagebrush stand selection is
influenced by snow depth (Patterson 1952, p. 184; Hupp and Braun 1989,
p. 827), availability of sagebrush above the snow to provide cover
(Connelly et al. 2004, pp. 4-13, and references therein) and, in some
areas, topography (e.g., elevation, slope and aspect; Beck 1977, p. 22;
Crawford et al. 2004, p. 5).
Many populations of sage-grouse migrate between seasonal ranges in
response to habitat distribution (Connelly et al. 2004, p. 3-5).
Migration can occur between winter and breeding and summer areas,
between breeding, summer, and winter areas, or not at all. Migration
distances of up to 161 km (100 mi) have been recorded (Patterson 1952,
p.189); however, distances vary depending on the locations of seasonal
habitats (Schroeder et al. 1999, p. 3). Migration distances for female
sage-grouse generally are less than for males (Connelly et al. 2004, p.
3-4), but in one study in Colorado, females traveled farther than males
(Beck 1977, p. 23). Almost no information is available regarding the
distribution and characteristics of migration corridors for sage-grouse
(Connelly et al. 2004, p. 4-19). Sage-grouse dispersal (permanent moves
to other areas) is poorly understood (Connelly et al. 2004, p. 3-5) and
appears to be sporadic (Dunn and Braun 1986, p. 89). Estimating an
``average'' home range for sage-grouse is difficult due to the large
variation in sage-grouse movements both within and among populations.
This variation is related to the spatial availability of habitats
required for seasonal use, and annual recorded home ranges have varied
from 4 to 615 square kilometers (km\2\) (1.5 to 237.5 square miles
(mi\2\)) (Connelly et al., in press a, p. 10).
Sage-grouse typically live between 3 and 6 years, but individuals
up to 9 years of age have been recorded in the wild (Connelly et al.
2004, p. 3-12). Hens typically survive longer due to a disproportionate
impact of predation on leks to males (Schroeder et al. 1999, p. 14).
Juvenile survival (from hatch to first breeding season) is affected by
food availability, habitat quality, harvest, and weather. Based on a
review of many field studies, juvenile survival rates range from 7 to
60 percent (Connelly et al. 2004, p. 3-12). The variation in juvenile
mortality rates may be associated with gender, weather, harvest rates,
age of brood female (broods with adult females have higher survival),
and with habitat quality (rates increase in poor habitats) (Schroeder
et al. 1999, p. 14; Connelly et al., in press a, p. 20). The average
annual survival rate for male sage-grouse (all ages combined)
documented in various studies ranged from 38 to 60 percent and 55 to 75
percent for females (Schroeder et al. 1999, p. 14). Higher female
survival rates account for a female-biased sex ratio in adult birds
(Schroeder 1999, p. 14; Johnsgard 2002, p. 621). The sex ratio of sage-
grouse breeding populations varies widely with values between 1.2 and 3
females per male being reported (Connelly et al., in press a, p. 23).
Although seasonal patterns of mortality have not been thoroughly
examined, over-winter mortality appears to be low (Connelly et al.
2000b, p. 229; Connelly et al. 2004, p. 9-4). While both males and
females are capable of breeding the first spring after hatch, young
males are rarely successful due to the dominance of older males on the
lek (Schroeder et al. 1999, p. 14). Nesting rates of yearling females
are 25 percent less than adult females (Schroeder et al. 1999, p. 13).
Habitat Description and Characteristics
Sage-grouse are dependent on large areas of contiguous sagebrush
(Patterson 1952, p. 48; Connelly et al. 2004, p. 4-1; Connelly et al.
in press a, p. 10; Wisdom et al. in press, p. 4), and large-scale
characteristics within surrounding landscapes influence sage-grouse
habitat selection (Knick and Hanser in press, p. 26). Sagebrush is the
most widespread vegetation in the intermountain lowlands in the western
United States (West and Young 2000, p. 259) and is considered one of
the most imperiled ecosystems in North America (Knick et al. 2003, p.
612; Miller et al. in press, p. 4, and references therein). Scientists
recognize 14 species and 13 subspecies of sagebrush (Connelly et al.
2004, p. 5-2; Miller et al. in press, p. 8), each with unique habitat
requirements and responses to perturbations (West and Young 2000, p.
259). Sagebrush species and subspecies occurrence in an area is
dictated by local soil type, soil moisture, and climatic conditions
(West 1983, p. 333; West and Young 2000, p. 260; Miller et al. in
press, pp. 8-11). The degree of dominance by sagebrush varies with
local site conditions and disturbance history. Plant associations,
typically defined by perennial grasses, further define distinctive
sagebrush communities (Miller and Eddleman 2000, pp. 10-14; Connelly et
al. 2004, p. 5-3), and are influenced by topography, elevation,
precipitation, and soil type. These ecological conditions influence the
response and resiliency of sagebrush and their associated understories
to natural and human-caused changes.
Sagebrush is typically divided into two groups, big sagebrush and
low sagebrush, based on their affinities for
[[Page 13917]]
different soil types (West and Young 2000, p. 259). Big sagebrush
species and subspecies, such as A. tridentata ssp. wyomingensis, are
limited to coarse-textured and/or well-drained sediments. Low
sagebrush, such as A. nova, typically occur where erosion has exposed
clay or calcified soil horizons (West 1983, p. 334; West and Young
2000, p. 261). Reflecting these soil differences, big sagebrush will
die if surfaces are saturated long enough to create anaerobic
conditions for 2 to 3 days (West and Young 2000, p. 259). Some low
sagebrush are more tolerant of occasionally supersaturated soils, and
many low sage sites are partially flooded during spring snowmelt. None
of the sagebrush taxa tolerate soils with high salinity (West 1983, p.
333; West and Young 2000, p. 257). Sagebrush that provide important
annual and seasonal habitats for sage-grouse include three subspecies
of big sagebrush (A. t. ssp. wyomingensis, A. t. ssp. tridentata and A.
t. ssp. vaseyana), two low forms of sagebrush (A. arbuscula (little
sagebrush) and A. nova), and A. cana ssp. cana (Miller et al. in press,
p. 8).
All species of sagebrush produce large ephemeral leaves in the
spring, which persist until reduced soil moisture occurs in the summer.
Most species also produce smaller, over-wintering leaves in the late
spring that last through summer and winter. Sagebrush have fibrous tap
root systems, which allow the plants to draw surface soil moisture, and
also to access water deep within the soil profile when surface water is
limited (West and Young 2000, p. 259). Most sagebrush flower in the
fall. However, during years of drought or other moisture stress,
flowering may not occur. Although seed viability and germination are
high, seed dispersal is limited. Sagebrush seeds, depending on the
species, remain viable for 1 to 3 years. However, Wyoming big sagebrush
seeds do not persist beyond the year of their production (West and
Young 2000, p. 260).
Sagebrush is long-lived, with plants of some species surviving up
to 150 years (West 1983, p. 340). They produce allelopathic chemicals
that reduce seed germination, seedling growth, and root respiration of
competing plant species and inhibit the activity of soil microbes and
nitrogen fixation. Sagebrush has resistance to environmental extremes,
with the exception of fire and occasionally defoliating insects (e.g.,
webworm (Aroga spp.); West 1983, p. 341). Most species of sagebrush are
killed by fire (West 1983, p. 341; Miller and Eddleman 2000, p. 17;
West and Young 2000, p. 259), and historic fire-return intervals were
as long as 350 years, depending on sagebrush type and environmental
conditions (Baker in press, p. 16). Natural sagebrush recolonization in
burned areas depends on the presence of adjacent live plants for a seed
source or on the seed bank, if present (Miller and Eddleman 2000, p.
17), and requires decades for full recovery.
Plants associated with the sagebrush understory vary, as does their
productivity. Both plant composition and productivity are influenced by
moisture availability, soil characteristics, climate, and topographic
position (Miller et al., in press, pp. 8-14). Forb abundance can be
highly variable from year to year and is largely affected by the amount
and timing of precipitation.
Very little sagebrush within its extant range is undisturbed or
unaltered from its condition prior to EuroAmerican settlement in the
late 1800s (Knick et al. 2003, p. 612, and references therein). Due to
the disruption of primary patterns, processes, and components of
sagebrush ecosystems since EuroAmerican settlement (Knick et al. 2003,
p. 612; Miller et al. in press, p. 4), the large range of abiotic
variation, the minimal short-lived seed banks, and the long generation
time of sagebrush, restoration of disturbed areas is very difficult.
Not all areas previously dominated by sagebrush can be restored because
alteration of vegetation, nutrient cycles, topsoil, and living
(cryptobiotic) soil crusts has exceeded recovery thresholds (Knick et
al. 2003, p. 620). Additionally, processes to restore sagebrush ecology
are relatively unknown (Knick et al. 2003, p. 620). Active restoration
activities are often limited by financial and logistic resources and
lack of political motivation (Knick et al. 2003, p. 620; Miller et al.
in press, p. 5) and may require decades or centuries (Knick et al.
2003, p. 620, and references therein). Meaningful restoration for
greater sage-grouse requires landscape, watershed, or eco-regional
scale context rather than individual, unconnected efforts (Knick et al.
2003, p. 623, and references therein; Wisdom et al. in press, p. 27).
Landscape restoration efforts require a broad range of partnerships
(private, State, and Federal) due to landownership patterns (Knick et
al. 2003, p. 623; see discussion of landownership below). Except for
areas where active restoration is attempted following disturbance
(e.g., mining, wildfire), management efforts in sagebrush ecosystems
are usually focused on maintaining the remaining sagebrush (Miller et
al. in press, p. 5; Wisdom et al. in press, pp. 26, 30).
Greater sage-grouse require large, interconnected expanses of
sagebrush with healthy, native understories (Patterson 1952, p. 9;
Knick et al. 2003, p. 623; Connelly et al. 2004, pp. 4-15; Connelly et
al. in press a, p. 10; Pyke in press, p. 7; Wisdom et al. in press, p.
4). There is little information available regarding minimum sagebrush
patch sizes required to support populations of sage-grouse. This is due
in part to the migratory nature of some but not all sage-grouse
populations, the lack of juxtaposition of seasonal habitats, and
differences in local, regional, and range-wide ecological conditions
that influence the distribution of sagebrush and associated
understories. Where home ranges have been reported (Connelly et al. in
press a, p. 10 and references therein), they are extremely variable (4
to 615 km\2\ range (1.5 to 237.5 mi\2\)). Occupancy of a home range
also is based on multiple variables associated with both local
vegetation characteristics and landscape characteristics (Knick et al.
2003, p. 621). Pyke (in press, p. 18) estimated that greater than 4,000
ha (9,884 ac) was necessary for population sustainability. However, he
did not indicate whether this value was for migratory or nonmigratory
populations, nor if this included juxtaposition of all seasonal
habitats. Large seasonal and annual movements emphasize the landscape
nature of the greater sage-grouse (Knick et al. 2003, p. 624; Connelly
et al. in press a, p. 10).
Range and Distribution of Sage-Grouse and Sagebrush
Prior to settlement of western North America by European immigrants
in the 19th century, greater sage-grouse occurred in 13 States and 3
Canadian provinces--Washington, Oregon, California, Nevada, Idaho,
Montana, Wyoming, Colorado, Utah, South Dakota, North Dakota, Nebraska,
Arizona, British Columbia, Alberta, and Saskatchewan (Schroeder et al.
1999, p. 2; Young et al. 2000, p. 445; Schroeder et al. 2004, p. 369).
Sagebrush habitats that potentially supported sage-grouse occurred over
approximately 1,200,483 km\2\ (463,509 mi\2\) before 1800 (Schroeder et
al. 2004, p. 366). Currently, greater sage-grouse occur in 11 States
(Washington, Oregon, California, Nevada, Idaho, Montana, Wyoming,
Colorado, Utah, South Dakota, and North Dakota), and 2 Canadian
provinces (Alberta and Saskatchewan), occupying approximately 56
percent of their historical range (Schroeder et al. 2004, p. 369).
Approximately 2 percent of the total range of the greater sage-grouse
[[Page 13918]]
occurs in Canada, with the remainder in the United States (Knick in
press, p. 14).
Sage-grouse have been extirpated from Nebraska, British Columbia,
and possibly Arizona (Schroeder et al. 1999, p. 2; Young et al. 2000 p.
445; Schroeder et al. 2004, p. 369). Current distribution of the
greater sage-grouse is estimated at 668,412 km\2\ (258,075 mi\2\;
Connelly et al. 2004, p. 6-9; Schroeder et al. 2004, p. 369). Changes
in distribution are the result of sagebrush alteration and degradation
(Schroeder et al. 2004, p. 363).
Sage-grouse distribution is associated with sagebrush (Schroeder et
al. 2004; p. 364), although sagebrush is more widely distributed.
However, sagebrush does not always provide suitable habitat due to
fragmentation and degradation (Schroeder et al. 2004, pp. 369, 372).
Very little of the extant sagebrush is undisturbed, with up to 50 to 60
percent having altered understories or having been lost to direct
conversion (Knick et al. 2003, p. 612 ). There also are challenges in
mapping altered and depleted understories, particularly in semi-arid
regions, so maps depicting only sagebrush as a dominant cover type are
deceptive in their reflection of habitat quality and, therefore, use by
sage-grouse (Knick et al. 2003, p. 616). As such, variations in the
quality of sagebrush habitats (from either abiotic or anthropogenic
events) are reflected by sage-grouse distribution and densities (Figure
1).
[GRAPHIC] [TIFF OMITTED] TP23MR10.000
Sagebrush occurs in two natural vegetation types that are
delineated by temperature and patterns of precipitation (Miller et al.
in press, p. 7). Sagebrush steppe ranges across the northern portion of
sage-grouse range, from British Columbia and the Columbia Basin,
through the northern Great Basin, Snake River Plain, and Montana, and
into the Wyoming Basin and northern Colorado. Great Basin sagebrush
occurs south of sagebrush steppe, and extends from the Colorado Plateau
westward into Nevada, Utah, and California (Miller et al. in press, p.
7). Other sagebrush types within greater sage-grouse range include
mixed-desert shrubland in the Bighorn Basin of Wyoming, and grasslands
in eastern Montana and Wyoming that also support A. cana and A.
filifolia (sand sagebrush) (Miller et al. in press, p. 7).
Due to differences in the ecology of sagebrush across the range of
the greater sage-grouse, the Western Association of Fish and Wildlife
Agencies (WAFWA) delineated seven Management Zones (MZs I-VII) based
primarily on floristic provinces (Figure 2; Table 1; Stiver et al.
2006, p. 1-6). The boundaries of these MZs were delineated based on
their ecological and biological attributes rather than on arbitrary
political boundaries (Stiver et al. 2006, p. 1-6). Therefore,
vegetation found within a MZ is similar and sage-grouse and their
habitats within these areas are likely to respond similarly to
environmental factors and management actions. The WAFWA conservation
strategy includes the Gunnison sage-grouse, and the boundary for MZ VII
includes its range (Stiver et al. 2006, pp. 1-1, 1-8), which does not
overlap with the range of the greater sage-grouse.
[[Page 13919]]
Table 1--The Management Zones of the greater sage-grouse as defined by
Stiver et al. (2006, pp. 1-7, 1-11).
------------------------------------------------------------------------
STATES AND
MZ PROVINCES INCLUDED FLORISTIC REGION
------------------------------------------------------------------------
I MT, WY, ND, SD, SK, Great Plains
AL
------------------------------------------------------------------------
II ID, WY, UT, CO Wyoming Basin
------------------------------------------------------------------------
III UT, NV, CA Southern Great
Basin
------------------------------------------------------------------------
IV ID, UT, NV, OR Snake River Plain
------------------------------------------------------------------------
V OR, CA, NV Northern Great
Basin
------------------------------------------------------------------------
VI WA Columbia Basin
------------------------------------------------------------------------
VII CO, UT Colorado Plateau
------------------------------------------------------------------------
[GRAPHIC] [TIFF OMITTED] TP23MR10.001
As stated above, due to the variability in habitat conditions,
sage-grouse are not evenly distributed across the range (Figure 1). The
MZs I, II, IV, and V encompass the core populations of greater sage-
grouse and have the highest reported densities (Table 2, Figures 1, 2;
Stiver et al. 2006, p. 1-12). The MZ III is composed of lower density
populations in the Great Basin, while fewer numbers of more dispersed
birds occur in MZ VI (Stiver et al. 2006, p. 1-7).
Table 2--Relative abundance of greater sage-grouse leks, and numbers of males attending leks by Management Zone, based on the mean number of individual leks and mean maximum number of males
attending leks by MZ during 2005-2007.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MZ Relative Abundance of Leks Relative Abundance of Males Attending Leks
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
I 0.17 0.15
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
II 0.48 0.50
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 13920]]
III 0.06 0.07
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
IV 0.19 0.18
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
V 0.09 0.10
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
VI 0.004 0.005
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
VII 0.003 0.003
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Land Ownership of Habitats
Greater sage-grouse extant habitats have multiple surface
ownerships, as reflected in Table 3. Most of the habitats occur on
Federal surfaces, a reflection of land disposal practices during
EuroAmerican settlement of the western United States (Knick in press,
pp. 5-10). Lands dominated by sagebrush that were disposed to private
ownership typically had deeper soils and greater available water
capacity or access to water (valley bottoms), reflecting their capacity
for agricultural development or increased grazing activities (Knick in
press, p. 15). The lands remaining in Federal ownership were of poorer
overall quality. The resulting low productivity on Federal surfaces
affects their ability to recover from disturbance (Knick in press, p.
17).
Federal agencies manage almost two-thirds of the sagebrush habitats
(Table 3). The Bureau of Land Management (BLM) manages just over half
of sage-grouse habitats, while the U.S. Forest Service (USFS) is
responsible for management of approximately 8 percent of sage-grouse
habitat (Table 3). Other Federal agencies, including the Service,
Bureau of Indian Affairs (BIA), Bureau of Reclamation (BOR), National
Park Service (NPS), Department of Defense (DOD), and Department of
Energy (DOE) also are responsible for sagebrush habitats, but at a much
smaller scale (Table 3). State agencies manage approximately 5 percent
of sage-grouse habitats.
Table 3--Percent surface ownership of total sagebrush area (km\2\ (mi\2\)) within the sage-grouse management zones (from Knick in press, p. 39). Other Federal agencies include the Service,
BOR, NPS, DOD, and DOE. MZ VII includes both Gunnison and greater sage-grouse.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sagebrush Management and Ownership
-----------------------------------------------------------------------------------------------------------------------
Sage-grouse MZ km\2\ mi\2\ Other Federal
BLM Percent Private Percent USFS Percent State Percent BIA Percent Percent
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
I Great Plains 50,264 19,407 17 66 2 7 4 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
II Wyoming Basin 108,771 41,996 49 35 4 7 4 1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
III Southern Great Basin 92,173 35,588 73 13 10 3 1 0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
IV Snake River Plain 134,187 51,810 53 29 11 6 1 0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
V Northern Great Basin 65,536 25,303 62 21 10 1 1 6
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
VI Columbia Basin 12,105 4,674 6 64 2 12 13 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
VII Colorado Plateau 17,534 6,770 42 36 6 6 9 1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTALS 480,570 185,549 52 31 8 5 3 1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Population Size
Estimates of greater sage-grouse abundance were mostly anecdotal
prior to the implementation of systematic surveys in the 1950s (Braun
1998, p. 139). Early reports suggested the birds were abundant
throughout their range, with estimates of historical populations
ranging from 1,600,000 to 16,000,000 birds (65 FR 51580, August 24,
2000). However, concerns about extinction were raised in early
literature due to market hunting and habitat alteration (Hornaday 1916,
pp. 181-185). Following a review of published literature and anecdotal
reports, Connelly et al. (2004, ES-1-3) concluded that the abundance of
sage-grouse has declined from presettlement (defined as 1800) numbers.
Most of the historical
[[Page 13921]]
population changes were the result of local extirpations, which has
been inferred from a 44 percent reduction in sage-grouse distribution
described by Schroeder et al. 2004 (Connelly et al. 2004, p. 6-9).
Population numbers are difficult to estimate due to the large range
of the species, physical difficulty in accessing some areas of habitat,
the cryptic coloration and behavior of hens (Garton et al. in press, p.
6), and survey protocols. Problems with inconsistent sampling protocols
for lek surveys (e.g., number of times a lek is counted, number of leks
surveyed in a year, observer bias, observer experience, time counted)
were identified by Walsh et al. (2006, pp. 61-64) and Garton et al. (in
press, p. 6), and many of those problems still persist (Stiver et al.
2006, p. 3-1). Additionally, estimating population sizes using lek data
is difficult as the relationship of those data to actual population
size (e.g., ratio of males to females, percent unseen birds) is usually
unknown (WAFWA 2008, p. 3). However, the annual counting of males on
leks remains the primary approach to monitor long-term trends of
populations (WAFWA 2008, p. 3), and standardized techniques are
beginning to be implemented throughout the species' range (Stiver et
al. 2006, pp. 3-1 to 3-16). The use of harvest data for estimating
population numbers also is of limited value since both harvest and the
population size on which harvest is based are estimates. Given the
limitations of these data, States usually rely on a combination of
actual counts of birds on leks and harvest data to estimate population
size. Estimates of populations by State, generated from a variety of
data sources, are provided in Table 4.
Table 4--Sage-grouse population estimates based on data from State wildlife agencies.
----------------------------------------------------------------------------------------------------------------
Estimated
Location Data Year Source Population
----------------------------------------------------------------------------------------------------------------
CA/2004 California/Nevada Sage-grouse 88,000
Conservation Team (2004, p.
26)
----------------------------------------------------------------------------------------------------------------
CO 2008 2007 CO Conservation plan, 22,646
based on adjusted male lek
counts (count + 1.6
multiplier, sex ratio
females:males) (Colorado
Greater Sage-grouse Steering
Committee 2008, p. 56)
----------------------------------------------------------------------------------------------------------------
ID 2007 Calculated based on assumption 98,700
of 5% of population is
harvested
(Service, unpublished data)....
----------------------------------------------------------------------------------------------------------------
MT 2007 Calculated based on assumption 62,320
of 5% of population is
harvested
(Service, unpublished data)....
----------------------------------------------------------------------------------------------------------------
ND 2007 2008 lek counts adjusted 308
(assumes 75% of males counted
at lek, & sex ratio of 2:1)
(A. Robinson, NDGFD, pers.
comm., 2008)
----------------------------------------------------------------------------------------------------------------
OR 2003 2003 Oregon Conservation Plan 40,000
Estimate (Hagen 2005, p. 27)
----------------------------------------------------------------------------------------------------------------
SD 2007 South Dakota Game and Fish web 1,500
page (last updated in 2007)
----------------------------------------------------------------------------------------------------------------
UT 2002 Utah Division of Wildlife 12,999
Resources (2002, p. 13)
----------------------------------------------------------------------------------------------------------------
WA 2003 Washington Division of Fish and 1,059
Wildlife (Stinson et al. 2004,
p. 21)
----------------------------------------------------------------------------------------------------------------
WY 2007 Calculated based on assumption 207,560
of 5% of population is
harvested
(Service, unpublished data)....
----------------------------------------------------------------------------------------------------------------
Can2006 Government of Canada 2010 450
----------------------------------------------------------------------------------------------------------------
Braun (1998, p. 141) estimated that the minimum 1998 rangewide
spring population numbered about 157,000 sage-grouse, derived from
numbers of males counted on leks. The same year, State wildlife
agencies within the range of the species estimated the population was
at least 515,000 based on lek counts and harvest data (Warren 2008,
pers. comm.). In 2000, we estimated the rangewide abundance of sage-
grouse was between a minimum of 100,000 (taken from Braun 1998, p. 141)
up to 500,000 birds (based on harvest data from Idaho, Montana, Oregon,
and Wyoming, with the assumption that 10 percent of the population is
typically harvested) (65 FR 51578, August 24, 2000). In 2003, based on
increased lek survey efforts, Connelly et al. (2004, p. 13-5) concluded
that rangewide population numbers were likely much greater than the
157,000 estimated by Braun (1998, p. 141), but they were unable to
generate a rangewide population estimate. Garton et al., (in press, p.
2) estimated a rangewide minimum of 88,816 males counted on leks in
2007, the last year data were formally collated and reported. Estimates
of historical populations range from 1,600,000 to 16,000,000 birds (65
FR 51580).
Population Trends
Although population numbers are difficult to estimate, the long-
term data collected from counting males on leks provides insight to
population trends. Periods of historical decline in sage-grouse
abundance occurred from the late 1800s to the early-1900s (Hornaday
1916, pp. 179-221; Crawford 1982, pp. 3-6; Drut 1994, pp. 2-5; WDFW
1995; Braun 1998, p. 140; Schroeder et al. 1999, p. 1). Other
noticeable declines in sage-grouse populations occurred in the 1920s
and 1930s, and then again in the 1960s and 1970s (Connelly and Braun
1997, pp. 3-4; Braun 1998, p. 141). Declines in the 1920s and 1930s
were attributed to hunting, and declines in the 1960s and 1970s were
primarily as a result of loss of habitat quality and quantity (Connelly
and Braun 1997, p. 2). State wildlife agencies were sufficiently
concerned with the decline in the 1920s and 1930s that many closed
their hunting seasons and others significantly reduced bag limits and
season lengths as a precautionary measure (Patterson 1952, pp. 30-33;
Autenrieth 1981, p. 10).
[[Page 13922]]
Using lek counts as an index for abundance, Connelly et al. (2004,
p. 6-71) reported rangewide declines from 1965 through 2003. Declines
averaged 2 percent per year from 1965 to 2003. The decline was more
dramatic from 1965 through 1985, with an average annual change of 3.5
percent. The rate of decline rangewide slowed to 0.37 percent annually
during 1986 to 2003 and some populations increased (Connelly et al.
2004, p. 6-71). Based on these analyses, Connelly et al. 2004 (p. 6-71)
estimated that sage-grouse population numbers in the late 1960s and
early 1970s were likely two to three times greater than current numbers
(Connelly et al. 2004, p. 6-71). Using a statistical population
reconstruction approach, Garton et al. (in press, p. 67) also
demonstrated a pattern of higher numbers of sage-grouse in the late
1960s and early 1970s, which was supported by data from several other
sources (Garton et al. in press, p. 68).
In 2008, WAFWA conducted new population trend analyses that
incorporated an additional 4 years of data beyond the Connelly et al.
2004 analysis (WAFWA 2008, entire). Although the WAFWA analyses used
different statistical techniques, lek counts also were used. WAFWA
results were similar to Connelly et al. (2004) in that a long-term
population decline was detected during 1965 to 2007 (average 3.1
percent annually; WAFWA 2008, p. 12). WAFWA attributed the decline to
the reduction in number of active leks (WAFWA 2008, p. 51). Similar to
Connelly et al. (2004), the WAFWA analyses determined that the rate of
decline lessened during 1985 to 2007 (average annual change of 1.4
percent annually) (WAFWA 2008, p. 58). Garton et al. (in press, pp. 68-
69) also had similar results. While the average annual rate of decline
has lessened since 1985 (3.1 to 1.4 percent), population declines
continue and populations are now at much lower levels than in the early
1980's. Therefore, these continuing negative trends at such low
relative numbers are concerning regarding long-term population
persistence. Similarly, short-term increases or stable trends, while on
the surface seem encouraging, do not indicate that populations are
recovering but may instead be a function of losing leks and not
increases in numbers (WAFWA 2008, p.51). Population stability may also
be compromised if cycles in sage-grouse populations (Schroeder et al.
1999, p. 15; Connelly et al. 2004, p.6-71) are lost, which current
analyses suggest, minimizing the opportunities for population recovery
if habitat were available (Garton 2009, pers. comm.).
Although the MZs were not formally adopted by WAFWA until 2006, the
population trend analyses conducted by Connelly et al. (2004) included
trend analyses based on the same floristic provinces used to define the
zones. While the average annual rate of change was not presented, the
results of those analyses indicated long-term declines in greater sage-
grouse for MZs I, II, III, IV and VI. Population trends in MZs V and
VII were increasing, but the trends were not statistically significant
(Connelly et al. 2004, p. 6-71; Stiver et al. 2006, p. 1-7). WAFWA
(2008) and Garton et al. (in press) population trend analyses did
consider MZs. The WAFWA (2008, pp. 13-27) and Garton et al. (in press,
pp. 22-62) reported that MZs I through VI had negative population
trends from 1965 to 2007. All population trend analyses had similar
results, with the exception of MZ VII (Table 5). However, this MZ has
one of the highest proportions of inactive leks (Garton et al. in
press, p. 65), which may imply that male numbers on the remaining leks
are increasing as birds relocate. The analysis of this MZ also suffered
from small sample sizes and therefore large confidence intervals
(Garton et al. in press, p. 217), so the trend may not actually reflect
the population status.
Table 5--Long-term population trend estimates for greater sage-grouse Management Zones.
----------------------------------------------------------------------------------------------------------------
Population Trend
Population Trend Population Trend Estimates Based on
States and Estimates 1965- Estimates Based on Annual Rates of
MZ Provinces 2003* (Connelly et Annual Rates of Change (%) 1965-
Included al. 2004) Change (%) 1965- 2007 (Garton et
2007(WAFWA 2008) al. in press)
----------------------------------------------------------------------------------------------------------------
I MT, WY, ND, SD, Long-term decline -2.9 -2.9
SK, AL
----------------------------------------------------------------------------------------------------------------
II ID, WY, UT, CO Long-term decline -2.7 -3.5
----------------------------------------------------------------------------------------------------------------
III UT, NV, CA Long-term decline -2.2 -10**
----------------------------------------------------------------------------------------------------------------
IV ID, UT, NV, OR Long-term decline -3.8 -4**
----------------------------------------------------------------------------------------------------------------
V OR, CA, NV Change -3.3 -2**
statistically
undetectable
----------------------------------------------------------------------------------------------------------------
VI WA Long-term decline -5.1 -6.5
----------------------------------------------------------------------------------------------------------------
VII CO, UT Change No detectable +34**
statistically trend
undetectable
----------------------------------------------------------------------------------------------------------------
*Average annual rate of change was not reported.
**Due to sample inadequacies for the statistical analyses used, only data from 1995 to 2007 could be used.
Differences in the MZ trends observed between the three analyses
are minimal, with the exception of MZs III, V, and VII. While the
results of Connelly et al. (2004) and WAFWA (2008) were similar for MZ
III, Garton et al. (in press) showed a larger rate of decline. This
difference may be due to the shortened time period (12 versus 42 years)
Garton et al. (in press) used for the analyses because some earlier
data were not suitable for the statistical procedures used. This
increased rate of decline was not observed for MZ IV where Garton et
al.'s (in press) analyses also spanned only 12 years, suggesting that
declines in MZ III may have recently accelerated. No explanation was
offered by WAFWA (2008) about the difference between their analyses and
Connelly et al. (2004) for MZ V. However, Garton et al. (in press)
results are similar to WAFWA for the same area.
The difference in the annual rate of change between Connelly et al.
(2004) and WAFWA (2008) as compared to Garton et al. (in press) for MZ
VII is substantial (Table 5). Garton et al. (in press) did not offer an
explanation of this difference, but Connelly et al.
[[Page 13923]]
(2004; as cited by (Stiver et al. 2006, p. 1-7)) indicated population
trends were increasing in this MZ, although those increases were not
statistically significant. However, Garton et al. (in press, pp. 62-63)
reported that the number of leks in MZ VII declined by 39 percent
during the same analysis period. The increase in annual rate of change
may simply reflect increases on remaining leks as habitat became more
limited.
In addition to calculating annual rates of change by MZ, Garton et
al (in press) also reported the percent change in number of males per
lek from 1965 to 2007, the percent change of active leks from 1965 to
2007, and minimum male population estimates in 2007 (Table 6). The
percent change in number of males per lek and the percent change in
active leks reflect population declines, and possibly habitat loss in
all MZs.
Table 6--Minimum male greater sage-grouse population estimates in 2007,
percent change in number of males per lek and percent change in number
of active leks between 1965 and 2007 by Management Zone (from Garton et
al. in press, pp. 22-64).
------------------------------------------------------------------------
Min Population Percent Change in
Est in 2007 of Percent Change
MZ ( of Males per Lek of Active Leks
males) (1965-2007) (1965-2007)
------------------------------------------------------------------------
I 14,814 -17 -22
------------------------------------------------------------------------
II 42,429 -30 -7
------------------------------------------------------------------------
III 6,851 -24 -16 ***
------------------------------------------------------------------------
IV 15,761 -54 -11***
------------------------------------------------------------------------
V 6,925 -17** -21**
------------------------------------------------------------------------
VI 315 -76 -57
------------------------------------------------------------------------
VII 241 -13 -39*
------------------------------------------------------------------------
*1995 to 2007 -- due to sample sizes, only data from this time period
were used.
**1985 to 2007 -- due to sample sizes, only data from this time period
were used.
***1975 to 2007 -- due to sample sizes, only data from this time period
were used.
In summary, since neither presettlement nor current numbers of
sage-grouse are accurately known, the actual rate and magnitude of
decline since presettlement times is uncertain. However, three groups
of researchers using different statistical methods (but the same lek
count data) concluded that rangewide greater sage-grouse have
experienced long-term population declines in the past 43 years, with
that decline lessening in the past 22 years. Many of these declines are
the result of loss of leks (WAFWA 2008, p. 51), indicating either a
direct loss of habitat or habitat function (Connelly and Braun 1997, p.
2). A recent increase in the annual rate of change for MZ VII may
simply be an anomaly of small population numbers, as other indicators
suggest this area is suffering habitat losses. A delayed response of
sage-grouse to changes in carrying capacity was identified by Garton et
al. (in press, p.71).
Connectivity
Greater sage-grouse are a landscape-scale species, requiring large
expanses of sagebrush to meet all seasonal habitat requirements. The
loss of habitat from fragmentation and conversion decreases the
connectivity between seasonal habitats potentially resulting in the
loss of the population (Doherty et al. 2008, p. 194). Loss of
connectivity also can increase population isolation (Knick and Hanser
in press, p. 4, and references therein) and, therefore, the probability
of loss of genetic diversity and extirpation from stochastic events.
Analyses of connectivity of greater sage-grouse across the
sagebrush landscape were conducted by Knick and Hanser (in press,
entire). Knick and Hanser (in press, p. 29) found that the average
movement between population centers (leks) of sage-grouse rangewide was
16.6 km (10.3 mi), with a standard deviation of 7.3 km (4.5 mi). Leks
within 18 km (11.2 mi) of each other had common features when compared
to leks further than this distance (Knick and Hanser in press, p. 17).
Therefore, they used a distance of 18 km (11.2 mi) between leks to
assess connectivity (movement between populations), but cautioned that
this distance may not accurately reflect genetic flow, or lack thereof,
between populations (Knick and Hanser in press, p. 28). Genetic
evidence suggests that exchange of individual birds has not been
restricted, although there is a gradation of allelic frequencies across
the species' range (Oyler-McCance and Quinn, in press, p. 14). This
result suggests that widespread movements (e.g., across several States)
are not occurring.
Population linkages primarily occurred within MZs, and connectivity
between MZs was limited, with the exception of MZs I (Great Plains) and
II (Wyoming Basin). Within MZs, the Wyoming Basin (MZ II) had the
highest levels of connectivity, followed by MZ IV (Snake River Plain)
and MZ I (Great Plains) (Knick and Hanser in press, p. 18). The MZ VI
(Columbia Basin) and VII (Colorado Plateau) had the least internal
connectivity, suggesting there was limited dispersal between leks and
an existing relatively high degree of isolation (Knick and Hanser in
press, p. 18). Areas along the edges of the sage-grouse range (e.g.,
Columbia Basin, Bi-State area) are currently isolated from other sage-
grouse populations (Knick and Hanser in press, p. 28).
Connectivity between sage-grouse MZs and the populations within
them declined across all three analysis periods examined: 1965-1974,
1980-1989, and 1998-2007. The decline in connectivity was due to the
loss of leks and reduced population size (Knick and Hanser in press, p.
29). Historic leks with low connectivity also were lost (Knick and
Hanser in press, p. 20), suggesting that current isolation of leks by
distance (including habitat fragmentation) will likely result in their
future loss (Knick and Hanser in press, p. 28). Small decreases in lek
connectivity resulted in large increases in probability of lek
abandonment (Knick and Hanser, in press, p. 29). Therefore, maintaining
habitat connectivity and sage-grouse population numbers are essential
for sage-grouse persistence.
[[Page 13924]]
Sagebrush distribution was the most important factor in maintaining
connectivity (Knick and Hanser in press, p. 32). This result suggests
that any activities that remove or fragment sagebrush habitats will
contribute to loss of connectivity and population isolation. This
conclusion is consistent with research from both Aldridge et al. (2008,
p. 988) and Wisdom et al. (in press, p. 13), which independently
identified the proximity of sagebrush patches and area in sagebrush
cover as the best predictors for sage-grouse presence.
Summary of Information Pertaining to the Five Factors
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
(50 CFR part 424) set forth procedures for adding species to the
Federal Lists of Endangered and Threatened Wildlife and Plants. In
making this finding, we summarize below information regarding the
status and threats to the greater sage-grouse in relation to the five
factors provided in section 4(a)(1) of the Act. Under section (4) of
the Act, we may determine a species to be endangered or threatened on
the basis of any of the following five factors: (A) Present or
threatened destruction, modification, or curtailment of habitat or
range; (B) overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. Our evaluation of threats is based
on information provided in the petition, available in our files, and
other sources considered to be the best scientific and commercial
information available, including published and unpublished studies and
reports.
Differences in ecological conditions within each MZ affect the
susceptibility of these areas to the various threats facing sagebrush
ecosystems and its potential for restoration. For example, Centaurea
diffusa (diffuse knapweed), an exotic annual weed, is most competitive
within shrub-grassland communities where antelope bitterbrush is
dominant (MZ VI), and Bromus tectorum (cheatgrass) is more dominant in
areas with minimal summer precipitation (MZs III and V) (Miller et al.,
in press, pp. 20-21). Therefore, we stratify our analyses by these MZs
because they represent zones within which ecological variation is less
than what it would be across the range of the species. This approach
allows us to better assess the impact and benefits of actions occurring
across the species' range and in turn more accurately assess the status
of the species.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Habitat or Range
Several factors are contributing to the destruction, modification,
or curtailment of the greater sage-grouse's habitat or range. Several
recent studies have demonstrated that sagebrush area is one of the best
landscape predictors of greater sage-grouse persistence (Aldridge et
al. 2008, p. 987; Doherty et al. 2008, p. 191; Wisdom et al., in press,
p. 17). Sagebrush habitats are becoming increasingly degraded and
fragmented due to the impacts of multiple threats, including direct
conversion, urbanization, infrastructure such as roads and powerlines
built in support of several activities, wildfire and the change in
wildfire frequency, incursion of invasive plants, grazing, and
nonrenewable and renewable energy development. Many of these threat
factors are exacerbated by the effects of climate change, which may
influence long-term habitat trends.
Habitat Conversion for Agriculture
Sagebrush is estimated to have covered roughly 120 million ha (296
million ac; Schroeder et al. 2004, p. 365) in western North America,
but large portions of that area have been cultivated for the production
of agricultural crops (e.g., potatoes, wheat; Schroeder et al. 1999, p.
16; 2000, p. 11). Western rangelands were converted to agricultural
lands on a large scale beginning with the series of Homestead Acts in
the 1800s (Braun 1998, p. 142, Hays et al. 1998, p. 26; Knick in press,
p. 4; Knick et al. in press, p. 11), especially where suitable deep
soil terrain and water were available (Rogers 1964, p.13, Schroeder and
Vander Haegen, 2009, in press, p. 3). Connelly et al. (2004, p. 5-55)
estimated that 24.9 million ha (61.5 million ac) within the sage-grouse
conservation area (SGCA) used for their assessment area (historic range
of Gunnison and greater sage-grouse plus a 50-km (31-mi) buffer) for
sage-grouse is now comprised of agricultural lands, although some areas
within the species' range are not sagebrush habitat, and the SGCA is
larger than the sage-grouse current distribution. An estimated 10
percent of sagebrush steppe that existed prior to EuroAmerican
settlement has been converted to agriculture (Knick et al. in press, p.
13). The remaining 90 percent is largely unsuited for agriculture
because irrigation is not considered to be feasible, topography and
soils are limiting, or temperatures are too extreme for many crops
(West 1996 cited in Knick et al. in press, p. 13).
Habitat conversion results in loss of habitat available for sage-
grouse use. The actual effect of this loss depends on the amount of
sagebrush lost, the type of seasonal habitat affected, and the
arrangement of habitat lost (large blocks or small patches) (Knick et
al. in press, p. 15). Direct impacts to sage-grouse depend on the
timing of conversion (e.g., loss of nests, eggs). Indirect effects of
agricultural activities adjoining sagebrush habitats include increased
predation with a resulting reduced sage-grouse nest success (Connelly
et al. 2004, p. 7-23), increased human presence, and habitat
fragmentation.
To estimate the area possibly influenced by these indirect effects,
Knick et al. (in press, p. 13) applied a ``high effective buffer'' out
to 6.9 km (4.3 mi) from agricultural lands, based on foraging distances
of synathropic (ecologically associated with humans) predators (e.g.
red foxes (Vulpes vulpes) and ravens (Corvus corax)). Given the
distribution of agricultural activities across the sagebrush range,
nearly three quarters of all sagebrush within range of sage-grouse has
been influenced by agricultural activities (falls within the high
effective buffer) (Knick et al. in press, p. 13). This influence
includes foraging distances for synathropic predators (Leu et al. 2008,
p. 1120; Knick et al. in press, p. 13), and associated features such as
irrigation ditches. Extensive conversion of sagebrush to agriculture
within a landscape has decreased abundance of sage-grouse in many
portions of their range (Knick and Hanser in press, p. 30, and
references therein).
Soil associations have resulted in disproportionate levels of
habitat conversion across different sagebrush communities. For example,
Artemisia tridentata ssp. vaseyana is found at lower elevations, in
soils that retain moisture 2 to 4 weeks longer than in well-drained,
but dry and higher elevation soils typical of A. t. ssp. wyomingensis
locations. Therefore, sagebrush communities dominated by basin big
sagebrush (A. t. ssp. tridentata) have been converted to agriculture
more extensively than have communities on poorer soil sites (Winward
2004, p. 29) (also see discussion below).
Large losses of sagebrush shrub-steppe habitats due to agricultural
conversion have occurred in some areas within the range of the greater
sage-grouse. This loss has been especially apparent in the Columbia
Basin of the Northwest (MZ VI), the Snake River Plain of Idaho (MZ IV)
(Schroeder et al. 2004, p. 370), and the Great Plains (MZ
[[Page 13925]]
I) (Knick et al. in press, p. 13). Hironaka et al. (1983, p. 27)
estimated that 99 percent of basin big sagebrush habitat in the Snake
River Plain has been converted to cropland. Between 1975 and 1992
alone, 29,762 ha (73,543 ac) of sagebrush habitat were converted to
cropland on the Upper Snake River Plain, a 74-percent increase in
cropland (Leonard et al. 2000, p. 268). The loss of this primarily
winter sage-grouse habitat is significantly related to subsequent sage-
grouse declines (Leonard et al. 2000, p. 268).
Prior to EuroAmerican settlement in the 19th century, Washington
had an estimated 42 million ha (103.8 million ac) of shrub-steppe
(Connelly et al. 2004, p. 7-22). Approximately 60 percent of the
original shrub-steppe habitat in Washington has been converted to
primarily agricultural uses (Dobler 1994, p. 2). Deep soils supporting
shrub-steppe communities in Washington within sage-grouse range
continue to be converted to agricultural uses (Vander Haegen et al.
2000, p. 1156), resulting in habitat loss. Agriculture is the dominant
land cover within sagebrush areas of Washington (42 percent) and Idaho
(19 percent) (Miller et al., in press, p. 18). In north-central Oregon
(MZ V), approximately 2.6 million ha (6.4 million ac) of habitat were
converted for agricultural purposes, essentially eliminating sage-
grouse from this area (Willis et al. 1993, p. 35). More broadly, across
the interior Columbia Basin of southern Idaho, northern Utah, northern
Nevada, eastern Oregon (MZ IV), and Washington, approximately 6 million
ha (14.8 million ac) of shrub-steppe habitat has been converted to
agricultural crops (Altman and Holmes 2000, p. 10).
Braun concluded that development of irrigation projects to support
agricultural production in areas where soils were sufficient to support
agriculture, in some cases conjointly with hydroelectric dam
construction, has resulted in additional sage-grouse habitat loss
(Braun 1998, p. 142). The reservoirs formed by these projects impacted
native shrub-steppe habitat adjacent to the rivers in addition to
supporting the irrigation and direct conversion of shrub-steppe lands
to agriculture. The projects precipitated conversion of large expanses
of upland shrub-steppe habitat in the Columbia Basin for irrigated
agriculture (65 FR 51578). The creation of these reservoirs also
inundated hundreds of kilometers of riparian habitats used by sage-
grouse broods (Braun 1998, p. 144). However, other small and isolated
reclamation projects (4,000 to 8,000 ha (10,000 to 20,000 ac)) were
responsible for three-fold localized increases in sage-grouse
populations (Patterson 1952, pp. 266-274) by providing water in a
semiarid environment, which provided additional insect and forb food
resources (e.g., Eden Reclamation Project in Wyoming). Benefits of
providing water through agricultural activities may now be negated due
to the threat of West Nile virus (WNv) (Walker et al. 2004, p. 4).
Five percent of the areas occupied by Great Basin sagebrush have
been converted to agriculture, urban or industrial areas (MZs III and
IV) (Miller et al. in press, p. 18). Five percent has also been
converted in the wheatgrass-needlegrass-shrubsteppe (MZ II, primarily
in north-central Wyoming) (Miller et al., in press, p. 18). In
sagebrush-steppe habitats, 14 percent of sagebrush habitats had been
converted to agriculture, urban or industrial activities (MZs II, IV,
V, and VI) (Miller et al., in press, pp. 17-18). Nineteen percent of
the Great Plains area (MZ I) has been converted to agriculture (Knick
et al. in press, p. 13). Conversions for sagebrush habitat types by
State are detailed in Table 7.
Table 7--Current sagebrush-steppe habitat and agricultural lands within
Great Basin sagebrush (as derived from LANDFIRE 2006 vegetation
coverage) (from Miller et al. in press, pp. 17-18).
------------------------------------------------------------------------
Percent
State Percent Sagebrush Agriculture
------------------------------------------------------------------------
Washington 23.7 42.4
------------------------------------------------------------------------
Montana 56.2* 7.5*
------------------------------------------------------------------------
Wyoming 66.0* 3.4*
------------------------------------------------------------------------
Idaho 55.0 18.6
------------------------------------------------------------------------
Oregon 64.5 8.6
------------------------------------------------------------------------
Nevada 58.7 1.3
------------------------------------------------------------------------
Utah 37.6 9.7
------------------------------------------------------------------------
California 49.8 8.0
------------------------------------------------------------------------
Colorado 40.6* 11.8*
------------------------------------------------------------------------
TOTAL 55.4 10.0
------------------------------------------------------------------------
*Analyses did not include sagebrush lands in the eastern portions of
Colorado, Montana, and Wyoming.
Aldridge et al. (2008, pp. 990-991) reported that sage-grouse
extirpations were more likely to occur in areas where cultivated crops
exceeded 25 percent. Their results supported the conclusions of others
(e.g., Schroeder 1997, p. 934; Braun 1998, p. 142; Aldridge and Brigham
2003, p. 30) that extensive cultivation and fragmentation of native
habitats have been associated with sage-grouse population declines.
Wisdom et al. (in press, p. 4) identified environmental factors
associated with the regional extirpation of sage-grouse. Areas still
occupied by sage-grouse have three times less area in agriculture and a
mean human density 26 times lower than extirpated areas (Wisdom et al.,
in press, p. 13). While sage-grouse may forage on agricultural crops
(see discussion below), they avoid landscapes dominated by agriculture
(Aldridge et al. 2008, p. 991). Conversions to croplands in southern
Idaho have resulted in isolation of sagebrush-dominated landscapes into
less productive regions north and south
[[Page 13926]]
of the Snake River Plain (Knick et al. 2003, p. 618). Therefore,
formerly continuous populations in this area are now disconnected
(Knick and Hanser in press, p. 52).
Sagebrush habitat continues to be converted for both dryland and
irrigated crop production (Montana Farm Services Agency (FSA) in litt,
2009; Braun 1998, p. 142; 65 FR 51578, August 24, 2000). The increasing
value of wheat and corn crops has driven new conversions in recent
years. For example, the acres of sagebrush converted to tilled
agriculture in Montana increased annually from 2005 to 2009, with
approximately 10,259 ha (25,351 ac) converted, primarily in the eastern
two-thirds of the State (MZ I) (Montana FSA in litt, 2009). In
addition, in 2008, a single conversion in central Montana totaled
between 3,345 and 10,000 ha (10,000 and 30,000 ac) (MZ I) (Hanebury
2008a, pers. comm.). Other large conversions occurred in the same part
of Montana in 2008, although these were unquantified (Hanebury 2008b,
pers. comm.). We were unable to gather any further information on crop
conversions of sagebrush habitats as there are no systematic efforts to
collect State or local data on conversion rates in the majority of the
greater sage-grouse range (GAO 2007, p. 16).
In addition to crop conversion for traditional crops, recent
interest in the development of crops for use as biofuels could
potentially impact sage-grouse. For example, the 2008 Farm Bill
authorized the Biomass Crop Assistance Program (BCAP), which provides
financial incentives to agricultural producers that establish and
produce eligible crops for conversion to bioenergy products (U.S.
Department of Agriculture (USDA) 2009b, p. 1). Further loss of
sagebrush habitats due to BCAP will negatively impact sage-grouse
populations. However, currently we have no way of predicting the
magnitude of BCAP impacts to sage-grouse (see discussion under Factor
D, below).
Although conversion of shrub-steppe habitat to agricultural crops
impacts sage-grouse through the loss of sagebrush on a broad scale,
some studies report the use of agricultural crops (e.g., alfalfa) by
sage-grouse. When alfalfa fields and other croplands are adjacent to
extant sagebrush habitat, sage-grouse have been observed feeding in
these fields, especially during brood-rearing (Patterson 1952, p. 203;
Rogers 1964, p. 53; Wallestad 1971, p. 134; Connelly et al. 1988,
p.120; Fischer et al. 1997, p. 89). Connelly et al. (1988, p. 120)
reported seasonal movements of sage-grouse to agricultural crops as
sagebrush habitats desiccated during the summer. However, use of
irrigated crops may not be beneficial to greater sage-grouse if it
increases exposure to pesticides (Knick et al. in press, p. 16) and WNv
(Walker et al. 2004, p. 4).
Some conversion of cropland to sagebrush has occurred in former
sage-grouse habitats through the USDA's voluntary Conservation Reserve
Program (CRP) which pays landowners a rental fee to plant permanent
vegetation on portions of their lands, taking them out of agricultural
production. In Washington State (Columbia Basin, MZ VI), sage-grouse
have declined precipitously in the Columbia Basin largely due to
conversion of sagebrush habitats to cropland (Schroeder and Vander
Haegen, in press, p. 4). Approximately 599,314 ha (1,480,937 ac) of
converted farmland had been enrolled in the CRP, almost all of which
was historically shrub-steppe (Schroeder and Vander Haegen in press, p.
5). Schroeder and Vander Haegen (in press, p. 20) found that CRP lands
that have been out of production long enough to allow re-establishment
of sagebrush and was juxtaposed to a relatively intact shrub-steppe
landscape was most beneficial to sage-grouse. There appears to be some
correlation with sage-grouse use of CRP and a slight increase in
population size in north-central Washington (Schroeder and Vander
Haegen in press, p. 21). Schroeder and Vander Haegen (in press, p. 21)
concluded that the loss of CRP due to expiration of the program or
incentives to produce biofuels would likely severely impact populations
in the Columbia Basin.
Although estimates of the numbers of acres enrolled rangewide in
CRP (and the number of acres soon to expire from CRP) are available,
the extent of cropland conversion to habitats beneficial to sage-grouse
(i.e., CRP lands planted with native grasses, forbs, and shrubs) is not
known for any other area barring the Columbia Basin. Thus, outside this
area, we cannot judge the overall impact of CRP land to sage-grouse
persistence.
Direct habitat loss and conversion also occurs via numerous other
landscape uses, including urbanization, livestock forage production,
road building, and oil pads. These activities are described in greater
detail below. Although we were unable to obtain an estimate of the
total amount of sagebrush habitats that have been lost due to these
activities, they have resulted in habitat fragmentation, as well as
habitat loss.
Urbanization
Low densities of indigenous peoples have been present for more than
12,000 years in the historical range of sage-grouse. By 1900, less than
1 person per km\2\ (1 person per 0.4 mi\2\) resided in 51 percent of
the 325 counties within the SGCA, and densities greater than 10 persons
per km\2\ (10 persons per 0.4 mi\2\) occurred in 4 percent of the
counties (Connelly et al. 2004, p. 7-24). By 2000, counties with less
than 1 person per km\2\ (1 person per 0.4 mi\2\) occurred in 31 percent
of the 325 counties and densities greater than 10 persons per km\2\ (10
persons per 0.4 mi\2\) occurred in 22 percent of the counties (Connelly
et al. 2004, p. 7-25). Today, the Columbia Basin (MZ VI) has the
highest density of humans while the Great Plains (MZ I) and Wyoming
Basin (MZ II) have the lowest (Knick et al. in press, p. 19). Growth in
the Great Plains (MZ I) continues to be slower than other areas. For
example, population densities have increased since 1990 by 7 percent in
the Great Plains (MZ I), by 19 percent in the Wyoming Basin (MZ II),
and by 31 percent in the Colorado Plateau (MZ VII) (Knick et al. in
press, p. 19).
The dominant urban areas in the sage-grouse range are located in
the Bear River Valley of Utah, the portion of Bonneville Basin
southeast of the Great Salt Lake, the Snake River Valley of southern
Idaho, and the Columbia River Valley of Washington (Rand McNally Road
Atlas 2003; Connelly et al. 2004, p. 7-25). Overall, approximately 1
percent of the amount of potential sagebrush (estimated historic range)
is now covered by lands classified as urban (Miller et al., in press,
p. 18).
Knick et al (in press, p. 107) examined the influence of
urbanization on greater sage-grouse MZs by adding a 6.9-km (4.3-mi)
buffer (an estimate of the foraging distances of mammalian and corvid
predators of sage-grouse) to the total area of urban land use. Based
the estimates using this approach, the Columbia Basin (MZ VI) was
influenced the most by urbanization with 48.4 percent of the sagebrush
area affected. The Northern Great Basin (MZ V) was influenced least
with 12.5 percent affected. Wyoming Basin (MZ II), which has the
majority of sage-grouse in the range, was at 18.4 percent affected.
Since 1950, the western U.S. population growth rate has exceeded
the national average (Leu and Hanser in press, p. 4). This growth has
led to increases in urban, suburban, and rural development. Rural
development has increased especially rapidly in recent decades. For
example, the amount of uninhabited area in the Great Basin
[[Page 13927]]
ecoregion has decreased from 90,000 km\2\ (34,749 mi\2\) in 1990 to
less than 12,000 km\2\ (4,633 mi\2\) in 2004 (Knick et al. in press, p.
20). Urbanization has directly eliminated some sage-grouse habitat
(Braun 1998, p. 145). Interrelated effects from urbanization include
construction of associated infrastructure (e.g., roads, powerlines, and
pipelines) and predation threats from the introduction of domestic pets
and increases in predators subsidized by human activities. In
particular, municipal solid waste landfills (landfills) and roads have
been shown to contribute to increases in common raven (Corvus corax)
populations (Knight et al. 1993 p. 470; Restani et al. 2001, p. 403;
Webb et al. 2004, p. 523). Ravens are known to be an important predator
on sage-grouse nests and have been considered a restraint on sage-
grouse population growth in some locations (Batterson and Morse 1948,
p. 14; Autenrieth 1981, p. 45; Coates 2007, p. 26). Landfills (and
roads) are found in every State within the greater sage-grouse range
and a number of these are located within or adjacent to sage-grouse
habitat.
Recent changes in demographic and economic trends have resulted in
greater than 60 percent of the Rocky Mountain West's counties
experiencing rural sprawl where rural areas are outpacing urban areas
in growth (Theobald 2003, p. 3). In some Colorado counties, up to 50
percent of sage-grouse habitat is under rural subdivision development,
and an estimated 3 to 5 percent of all sage-grouse historical habitat
in Colorado has already been converted into urban areas (Braun 1998, p.
145). We are unaware of similar estimates for other States within the
range of the greater sage-grouse and, therefore, cannot determine the
effects of this factor on a rangewide basis. Rural development has
increasingly taken the form of low-density (approximately 6 to 25 homes
per km\2\ (6 to 25 homes per 0.4 mi\2\)) home development or exurban
growth (Hansen et al. 2005, p. 1894). Between 1990 and 2000, 120,000
km\2\ (46,332 mi\2\) of land were developed at exurban densities
nationally (Theobald 2001, p. 553). However, this value includes
development nationwide, and we are unable to report values specifically
for sagebrush habitats. However, within the Great Basin (including
California, Idaho, Nevada, and Utah), human populations have increased
69 percent and uninhabited areas declined by 86 percent between 1990
and 2004 (Leu and Hanser in press, p. 19). Similar to higher density
urbanization, exurban development has the potential to negatively
affect sage-grouse populations through fragmentation or other indirect
habitat loss, increased infrastructure, and increased predation.
In modeling sage-grouse persistence, Aldridge et al. (2008, pp.
991-992) found that the density of humans in 1950 was the best
predictor of sage-grouse extirpation among the human population metrics
considered (including increasing human population growth). Sage-grouse
extirpation was more likely in areas having a moderate human population
density of at least 4 people per km\2\ (4 people per 0.4 mi\2\).
Increasing human populations were not a good predictor of sage-grouse
persistence, most likely because much of the growth occurred in areas
that are already no longer suitable for sage-grouse. Aldridge et al.
(2008, p. 990) also reported that, based on their models, sage-grouse
require a minimum of 25 percent sagebrush for persistence in an area. A
high probability of persistence required 65 percent sagebrush or more.
This result is similar to the results by Wisdom et al. (in press, p.
18) who reported that human density was 26 times greater in extirpated
sage-grouse areas than in currently occupied range. Therefore, human
population growth that results in exurban development in sagebrush
habitats will reduce the likelihood of sage-grouse persistence in the
area. Given the current demographic and economic trends in the Rocky
Mountain West, we believe that rates of urbanization will continue
increasing, resulting in further habitat fragmentation and degradation
and decreasing the probability of long-term sage-grouse persistence.
Infrastructure in Sagebrush Habitats
Habitat fragmentation is the separation or splitting apart of
previously contiguous, functional habitat components of a species.
Fragmentation can result from direct habitat losses that leave the
remaining habitat in noncontiguous patches, or from alteration of
habitat areas that render the altered patches unusable to a species
(i.e., functional habitat loss). Functional habitat losses include
disturbances that change a habitat's successional state or remove one
or more habitat functions; physical barriers that preclude use of
otherwise suitable areas; and activities that prevent animals from
using suitable habitat patches due to behavioral avoidance.
Sagebrush communities exhibit a high degree of variation in their
resistance and resilience to change, beyond natural variation.
Resistance (the ability to withstand disturbing forces without
changing) and resilience (the ability to recover once altered)
generally increase with increasing moisture and decreasing
temperatures, and also can be linked to soil characteristics (Connelly
et al. 2004, p. 13-6). However, most extant sagebrush habitat has been
altered since European immigrant settlement of the West (Baker et al.
1976, p. 168; Braun 1998, p. 140; Knick et al. 2003, p. 612; Connelly
et al. 2004, p. 13-6), and sagebrush habitat continues to be fragmented
and lost (Knick et al. 2003, p. 614) through the factors described
below. The cumulative effects of habitat fragmentation have not been
quantified over the range of sagebrush and most fragmentation cannot be
attributed to specific land uses (Knick et al. 2003, p. 616). However,
in large-scale analysis of the collective effect of anthropogenic
features (or the ``human footprint'') in the western United States, Leu
et al. (2008, p. 1130) found that 13 percent of the area was affected
in some way by anthropogenic features (i.e., fragmentation). Areas with
the lowest ``human footprint'' (i.e., no to slight development or use)
experienced above-average human population growth between 1990 and
2000. There is significant evidence these areas will experience
increasing habitat fragmentation in the future (Leu et al. 2008, p.
1133). Although the area covered by these estimates includes all
western states, we believe the general points regarding effects of
anthropogenic features apply to sage-grouse habitat.
Fragmentation of sagebrush habitats has been cited as a primary
cause of the decline of sage-grouse populations because the species
requires large expanses of contiguous sagebrush (Patterson 1952, pp.
192-193; Connelly and Braun 1997, p. 4; Braun 1998, p. 140; Johnson and
Braun 1999, p. 78; Connelly et al. 2000a, p. 975; Miller and Eddleman
2000, p. 1; Schroeder and Baydack 2001, p. 29; Johnsgard 2002, p. 108;
Aldridge and Brigham 2003, p. 25; Beck et al. 2003, p. 203; Pedersen et
al. 2003, pp. 23-24; Connelly et al. 2004, p. 4-15; Schroeder et al.
2004, p. 368; Leu et al. in press, p. 19). The negative effects of
habitat fragmentation have been well documented in numerous bird
species, including some shrub-steppe obligates (Knick and Rotenberry
1995, pp. 1068-1069). However, prior to 2005, detailed data to assess
how fragmentation influences specific greater sage-grouse life-history
parameters such as productivity, density, and home range were not
available. More recently, several studies have documented negative
effects of fragmentation as a
[[Page 13928]]
result of oil and gas development and its associated infrastructure
(see discussion of Energy Development below) on lek persistence, lek
attendance, winter habitat use, recruitment, yearling annual survival
rate, and female nest site choice (Holloran 2005, p. 49; Aldridge and
Boyce 2007, pp. 517-523; Walker et al. 2007a, pp. 2651-2652; Doherty et
al. 2008, p. 194). Wisdom et al. (in press, p. 18) reported that a
variety of human developments, including roads, energy development, and
other factors that contribute to habitat fragmentation have contributed
to or been associated with sage-grouse extirpation. Estimating the
impact of habitat fragmentation on sage-grouse is complicated by time
lags in response to habitat changes (Garton et al., in press, p. 71),
particularly since these long-lived birds will continue to return to
altered breeding areas (leks, nesting areas, and early brood-rearing
areas) due to strong site fidelity despite nesting or productivity
failures (Wiens and Rotenberry 1985, p. 666).
Powerlines
Power grids were first constructed in the United States in the late
1800s. The public demand for electricity has grown as human population
and industrial activities have expanded (Manville 2002, p. 5),
resulting in more than 804,500 km (500,000 mi) of transmission lines
(lines carrying greater than 115,000 volts (115 kilovolts (kV)) by 2002
within the United States (Manville 2002, p. 4). A similar estimate is
not available for distribution lines (lines carrying less than
69,000volts (69kV)), and we are not aware of data for Canada. Within
the SGCA, Knick et al. (in press, p. 21) showed that powerlines cover a
minimum of 1,089km\2\ (420.5 mi).
Due to the potential spread of invasive species and predators as a
result of powerline construction the impact from the powerline is
greater than the actual footprint. Knick et al. (in press, p. 111)
estimated these impacts may influence up to 39 percent of all sagebrush
in the SGCA. Powerlines can directly affect greater sage-grouse by
posing a collision and electrocution hazard (Braun 1998, pp. 145-146;
Connelly et al. 2000a, p. 974), and can have indirect effects by
decreasing lek recruitment (Braun et al. 2002, p. 10), increasing
predation (Connelly et al. 2004, p. 13-12), fragmenting habitat (Braun
1998, p. 146), and facilitating the invasion of exotic annual plants
(Knick et al. 2003, p. 612; Connelly et al. 2004, p. 7-25). In 1939,
three adult sage-grouse died as a result of colliding with a telegraph
line in Utah (Borell 1939, p. 85). Both Braun (1998, p. 145) and
Connelly et al. (2000a, p. 974) report that sage-grouse collisions with
powerlines occur, although no specific instances were presented. There
was also an unpublished observation reported by Aldridge and Brigham
(2003, p. 31). In 2009, two sage-grouse died from electrocution after
colliding with a powerline in the Mono Basin of California (Gardner
2009, pers. comm.). We were unable to find any other documentation of
other collisions or electrocution of sage-grouse resulting from
powerlines.
In areas where the vegetation is low and the terrain relatively
flat, power poles provide an attractive hunting and roosting perch, as
well as nesting stratum for many species of raptors and corvids
(Steenhof et al. 1993, p. 27; Connelly et al. 2000a, p. 974; Manville
2002, p. 7; Vander Haegen et al. 2002, p. 503). Power poles increase a
raptor's range of vision, allow for greater speed during attacks on
prey, and serve as territorial markers (Steenhof et al. 1993, p. 275;
Manville 2002, p. 7). Raptors may actively seek out power poles where
natural perches are limited. For example, within 1 year of construction
of a 596-km (372.5-mi) transmission line in southern Idaho and Oregon,
raptors and common ravens began nesting on the supporting poles
(Steenhof et al. 1993, p. 275). Within 10 years of construction, 133
pairs of raptors and ravens were nesting along this stretch (Steenhof
et al. 1993, p. 275). Raven counts have increased by approximately 200
percent along the Falcon-Gondor transmission line corridor in Nevada
within 5 years of construction (Atamian et al. 2007, p. 2). The
increased abundance of raptors and corvids within occupied sage-grouse
habitats can result in increased predation. Ellis (1985, p. 10)
reported that golden eagle (Aquila chryrsaetos) predation on sage-
grouse on leks increased from 26 to 73 percent of the total predation
after completion of a transmission line within 200 meters (m) (220
yards (yd)) of an active sage-grouse lek in northeastern Utah. The lek
was eventually abandoned, and Ellis (1985, p. 10) concluded that the
presence of the powerline resulted in changes in sage-grouse dispersal
patterns and caused fragmentation of the habitat.
Leks within 0.4 km (0.25 mi) of new powerlines constructed for
coalbed methane development in the Powder River Basin of Wyoming had
significantly lower growth rates, as measured by recruitment of new
males onto the lek, compared to leks further from these lines, which
were presumed to be the result of increased raptor predation (Braun et
al. 2002, p. 10). Within the SGCA, Connelly et al. (2004, p. 7-26)
estimated that the area potentially influenced by additional perches
for corvids and raptors provided by powerlines, assuming a 5- to 6.9-km
(3.1- to 4.3-mi) radius buffer around the perches based on the average
foraging distance of these predators, was 672,644 to 837,390 km\2\
(259,641 to 323,317 mi\2\), or 32 to 40 percent of the SGCA. The actual
impact on the area would depend on corvid and raptor densities within
the area, the amount of cover to reduce predation risk at sage-grouse
nests, and other factors (see discussion in Factor C, below).
The presence of a powerline may fragment sage-grouse habitats even
if raptors are not present. Braun (1998, p. 146) found that use of
otherwise suitable habitat by sage-grouse near powerlines increased as
distance from the powerline increased for up to 600 m (660 yd) and,
based on that unpublished data, reported that the presence of
powerlines may limit sage-grouse use within 1 km (0.6 mi) in otherwise
suitable habitat. Similar results were recorded for other grouse
species. Pruett et al. (2009, p. 6) found that lesser and greater
prairie-chickens (Tympanuchus pallidicinctus and T. cupido,
respectively) avoided otherwise suitable habitat near powerlines.
Additionally, both species also crossed powerlines less often than
nearby roads, which suggests that powerlines are a particularly strong
barrier to movement (Pruett et al. 2009, p. 6).
Sage-grouse also may avoid powerlines as a result of the
electromagnetic fields (Wisdom et al. in press, p. 19). Electromagnetic
fields have been demonstrated to alter the behavior, physiology,
endocrine systems, and immune function in birds, with negative
consequences on reproduction and development (Fernie and Reynolds 2005,
p. 135). Birds are diverse in their sensitivities to electromagnetic
field exposures, with domestic chickens being very sensitive. Many
raptor species are less affected (Fernie and Reynolds 2005, p. 135).
Linear corridors through sagebrush habitats can facilitate the
spread of invasive species, such as Bromus tectorum (Gelbard and Belnap
2003, pp. 424-426; Knick et al. 2003, p. 620; Connelly et al. 2004, p.
1-2). However, we were unable to find any information regarding the
amount of invasive species incursion as a result of powerline
construction.
Powerlines are common to nearly every type of anthropogenic habitat
use, except perhaps some forms of agricultural development (e.g.,
livestock grazing) and fire. Although we were
[[Page 13929]]
unable to find an estimate of all future proposed powerlines within
currently occupied sage-grouse habitats, we anticipate that powerlines
will continue to increase into the foreseeable future, particularly
given the increasing development of energy resources and urban areas.
For example, up to 8,579 km (5,311 mi) of new powerlines are predicted
for the development of the Powder River Basin coal-bed methane field in
northeastern Wyoming (BLM 2003) in addition to the approximately 9,656
km (6,000 mi) already constructed in that area. In November 2009, nine
Federal agencies signed a Memorandum of Understanding to expedite the
building of new transmission lines on Federal lands. If these lines
cross sage-grouse habitats, sage-grouse will likely be negatively
affected.
Communication Towers
Within sage-grouse habitats, 9,510 new communication towers have
been constructed within recent years (Connelly et al. 2004, p. 13-7).
While millions of birds are killed annually in the United States
through collisions with communication towers and their associated
structures (e.g., guy wires, lights) (Shire et al. 2000, p. 5; Manville
2002, p. 10), most documented mortalities are of migratory songbirds.
We were unable to determine if any sage-grouse mortalities occur as a
result of collision with communication towers or their supporting
structures, as most towers are not monitored and those that are lie
outside the range of the species (Kerlinger 2000, p. 2; Shire et al.
2000 p. 19). Cellular towers have the potential to cause sage-grouse
mortality via collisions, to influence movements through avoidance of a
tall structure (Wisdom et al. in press, p. 20), or to provide perches
for corvids and raptors (Steenhof et al. 1993, p. 275; Connelly et al.
2004, p. 13-7).
In a comparison of sage-grouse locations in extirpated areas of
their range (as determined by museum species and historical
observations) and currently occupied habitats, the distance to cellular
towers was nearly twice as far from grouse locations in currently
occupied habitats than extirpated areas (Wisdom et al. in press, p.
13). The results may have been influenced by location as many cellular
towers are close to intensive human development. However, such
associations with other indicators of development and cellular towers
were low (Wisdom et al. in press, p. 20). High levels of
electromagnetic radiation within 500 m (547 yd) of all towers have been
linked to decreased populations and reproductive performance of some
bird and amphibian species (Wisdom et al. in press, p. 19, and
references therein). We do not know if greater sage-grouse are
negatively impacted by electromagnetic radiation, or if their avoidance
of these structures is a response to increased predation risk.
Fences
Fences are used to delineate property boundaries and for livestock
management (Braun 1998, p. 145; Connelly et al. 2000a, p. 974). The
effects of fencing on sage-grouse include direct mortality through
collisions, creation of predator (raptor) and corvid perch sites, the
potential creation of predator corridors along fences (particularly if
a road is maintained next to the fence), incursion of exotic species
along the fencing corridor, and habitat fragmentation (Call and Maser
1985, p. 22; Braun 1998, p. 145; Connelly et al. 2000a, p. 974; Beck et
al. 2003, p. 211; Knick et al. 2003, p. 612; Connelly et al. 2004, p.
1-2).
More than 1,000 km (625 mi) of fences were constructed annually in
sagebrush habitats from 1996 through 2002, mostly in Montana, Nevada,
Oregon, and Wyoming (Connelly et al. 2004, p. 7-34). Over 51,000 km
(31,690 mi) of fences were constructed on BLM lands supporting sage-
grouse populations between 1962 and 1997 (Connelly et al. 2000a, p.
974). Sage-grouse frequently fly low and fast across sagebrush flats,
and fences can create a collision hazard (Call and Maser 1985, p. 22).
Thirty-six carcasses of sage-grouse were found near Randolph, Utah,
along a 3.2-km (2-mi) fence within 3 months of its construction (Call
and Maser 1985, p. 22). Twenty-one incidents of mortality through fence
collisions near Pinedale, Wyoming, were reported in 2003 to the BLM
(Connelly et al. 2004, p. 13-12). A recent study in Wyoming confirmed
146 sage-grouse fence strike mortalities over a 31-month period along a
7.6-km (4.6-mi) stretch of 3-wire BLM range fence (Christiansen 2009).
Not all fences present the same mortality risk to sage-grouse.
Mortality risk appears to be dependent on a combination of factors
including design of fencing, landscape topography, and spatial
relationship with seasonal habitats (Christiansen 2009, unpublished
data). Although the effects of direct strike mortality on populations
are not understood, fences are ubiquitous across the landscape. In many
parts of the sage-grouse range (primarily Montana, Nevada, Oregon,
Wyoming) fences exceed densities of more than 2 km/km\2\ (1.2 mi/0.4
mi\2\; Knick et al. in press, p. 32). Fence collisions continue to be
identified as a source of mortality for sage-grouse, and we expect this
source of mortality to continue into the foreseeable future (Braun
1998, p. 145; Connelly et al. 2000a, p. 974; Oyler-McCance et al. 2001,
p. 330; Connelly et al. 2004, p. 7-3).
Fence posts create perching places for raptors and corvids, which
may increase their ability to prey on sage-grouse (Braun 1998, p. 145;
Oyler-McCance et al. 2001, p. 330; Connelly et al. 2004, p. 13-12). We
anticipate that the effect on sage-grouse populations through the
creation of new raptor perches and predator corridors into sagebrush
habitats is similar to that of powerlines discussed previously (Braun
1998, p. 145; Connelly et al. 2004, p. 7-3). Fences and their
associated roads also facilitate the spread of invasive plant species
that replace sagebrush plants upon which sage-grouse depend (Braun
1998, p. 145; Connelly et al. 2000a, p. 973; Gelbard and Belnap 2003,
p. 421; Connelly et al. 2004, p. 7-3). Greater sage-grouse avoidance of
habitat adjacent to fences, presumably to minimize the risk of
predation, effectively results in habitat fragmentation even if the
actual habitat is not removed (Braun 1998, p. 145).
Roads
Interstate highways and major paved roads cover approximately 2,500
km\2\ (965 mi\2\) or 0.1 percent of the SGCA (Knick et al. in press, p.
21). Based on applying a 7-km (4.3-mi) buffer to estimate the potential
impact of secondary effects from roads, interstates and highways are
estimated to influence 851,044 km\2\ (328,590 mi\2\) or 41 percent of
the SGCA. Additionally, secondary paved roads are heavily distributed
throughout most of the SGCA, existing at densities of up to greater
than 5 km/km\2\ (3.1 mi/mi\2\). Taken together, 95 percent of all sage-
grouse habitats were within 2.5 km (1.5 mi) of a mapped road, and
almost no area of sagebrush was greater the 6.9 km (4.3 mi) from a
mapped road (Knick et al. in press, p. 21).
Impacts from roads may include direct habitat loss, direct
mortality, barriers to migration corridors or seasonal habitats,
facilitation of predators and spread of invasive vegetative species,
and other indirect influences such as noise (Forman and Alexander 1998,
pp. 207-231). Sage-grouse mortality resulting from collisions with
vehicles does occur (Patterson 1952, p. 81), but mortalities are
typically not monitored or recorded. Therefore, we are unable to
determine the importance of this factor on sage-grouse populations.
Data regarding how roads affect seasonal habitat availability
[[Page 13930]]
for individual sage-grouse populations by creating barriers and the
ability of greater sage-grouse to reach these areas were not available.
Road development within Gunnison sage-grouse (C. minimus) habitats
impeded movement of local populations between the resultant patches,
with grouse road avoidance presumably being a behavioral means to limit
exposure to predation (Oyler-McCance et al. 2001, p. 330).
Roads can provide corridors for predators to move into previously
unoccupied areas. For some mammalian species, dispersal along roads has
greatly increased their distribution (Forman and Alexander 1998, p.
212; Forman 2000, p. 33). Corvids also use linear features such as
primary and secondary roads as travel routes, expanding their movements
into previously unused regions (Knight and Kawashima 1993, p. 268;
Connelly et al. 2004, p. 12-3). In an analysis of anthropogenic
impacts, at least 58 percent of the SGCA had a high or medium estimated
presence of corvids (Connelly et al. 2004, p. 12-6). Corvids are
important sage-grouse nest predators and in a study in Nevada were
positively identified via video recorder as responsible for more than
50 percent of nest predations in the study area (Coates 2007, pp. 26-
30). Bui (2009, p. 31) documented ravens following roads in oil and gas
fields during foraging. Additionally, highway rest areas provide a
source of food and perches for corvids and raptors, and facilitate
their movements into surrounding areas (Connelly et al. 2004, p. 7-25).
The presence of roads increases human access and resulting
disturbance effects in remote areas (Forman and Alexander 1998, p. 221;
Forman 2000, p. 35; Connelly et al. 2004, pp. 7-6 to 7-25). Increases
in legal and illegal hunting activities resulting from the use of roads
built into sagebrush habitats have been documented (Hornaday 1916, p.
183; Patterson 1952, p. vi). However, the actual current effect of
these increased activities on sage-grouse populations has not been
determined. Roads also may facilitate access for rangeland habitat
treatments, such as disking or mowing (Connelly et al. 2004, p. 7-25),
resulting in subsequent direct habitat losses. New roads are being
constructed to support development activities within the greater sage-
grouse extant range. In the Powder River Basin of Wyoming, up to 28,572
km (17,754 mi) of roads to support coalbed methane development are
proposed (BLM 2003).
The expansion of road networks contributes to exotic plant
invasions via introduced road fill, vehicle transport, and road
maintenance activities (Forman and Alexander 1998, p. 210; Forman 2000,
p. 32; Gelbard and Belnap 2003, p. 426; Knick et al. 2003, p. 619;
Connelly et al. 2004, p. 7-25). Invasive species are not limited to
roadsides, but also encroach into surrounding habitats (Forman and
Alexander 1998, p. 210; Forman 2000, p. 33; Gelbard and Belnap 2003, p.
427). In their study of roads on the Colorado Plateau of southern Utah,
Gelbard and Belnap (2003, p. 426) found that improving unpaved four-
wheel drive roads to paved roads resulted in increased cover of exotic
plant species within the interior of adjacent plant communities. This
effect was associated with road construction and maintenance activities
and vehicle traffic, and not with differences in site characteristics.
The incursion of exotic plants into native sagebrush systems can
negatively affect greater sage-grouse through habitat losses and
conversions (see further discussion in Invasive Plants, below).
Additional indirect effects of roads may result from birds'
behavioral avoidance of road areas because of noise, visual
disturbance, pollutants, and predators moving along a road. The absence
of vegetation in arid and semiarid regions that may buffer these
impacts further exacerbates the problem (Suter 1978, p. 6). Male sage-
grouse lek attendance was shown to decline within 3 km (1.9 mi) of a
methane well or haul road with traffic volume exceeding one vehicle per
day (Holloran 2005, p. 40). Male sage-grouse depend on acoustical
signals to attract females to leks (Gibson and Bradbury 1985, p. 82;
Gratson 1993, p. 692). If noise interferes with mating displays, and
thereby female attendance, younger males will not be drawn to the lek
and eventually leks will become inactive (Amstrup and Phillips 1977, p.
26; Braun 1986, pp. 229-230).
Dust from roads and exposed roadsides can damage vegetation through
interference with photosynthetic activities. The actual amount of
potential damage depends on winds, wind direction, the type of
surrounding vegetation and topography (Forman and Alexander 1998, p.
217). Chemicals used for road maintenance, particularly in areas with
snowy or icy precipitation, can affect the composition of roadside
vegetation (Forman and Alexander 1998, p. 219). We were unable to find
any data relating these potential effects directly to impacts on sage-
grouse population parameters.
In a study on the Pinedale Anticline in Wyoming, sage-grouse hens
that bred on leks within 3 km (1.9 mi) of roads associated with oil and
gas development traveled twice as far to nest as did hens bred on leks
greater than 3 km (1.9 mi) from roads. Nest initiation rates for hens
bred on leks close to roads also were lower (65 versus 89 percent)
affecting population recruitment (33 versus 44 percent) (Lyon 2000, p.
33; Lyon and Anderson 2003, pp. 489-490). Lyon and Anderson (2003, p.
490) suggested that roads may be the primary impact of oil and gas
development to sage-grouse, due to their persistence and continued use
even after drilling and production have ceased. Braun et al. (2002, p.
5) suggested that daily vehicular traffic along road networks for oil
wells can impact sage-grouse breeding activities based on lek
abandonment patterns.
In a study of 804 leks within 100 km (62.5 mi) of Interstate 80 in
southern Wyoming and northeastern Utah, Connelly et al. (2004, p. 13-
12) found that there were no leks within 2 km (1.25 mi) of the
interstate and only 9 leks were found between 2 and 4 km (1.25 and 2.5
mi) along this same highway. The number of active leks increased with
increasing distance from the interstate. Lek persistence and activity
relative to distance from the interstate also were measured. The
distance of a lek from the interstate was a significant predictor of
lek activity, with leks further from the interstate more likely to be
active. An analysis of long-term changes in populations between 1970
and 2003 showed that leks closest (within 7.5 km (4.7 mi)) to the
interstate declined at a greater rate than those further away (Connelly
et al. 2004, p. 13-13). Extirpated sage-grouse range was 60 percent
closer to highways (Wisdom et al. in press, p. 18). What is not clear
from these studies is what specific factor relative to roads (e.g.,
noise, changes in vegetation, etc.) sage-grouse are responding to.
Connelly et al. (2004, p. 13-13) caution that they have not included
other potential sources of indirect disturbance (e.g., powerlines) in
their analyses.
Aldridge et al. (2008, p. 992) did not find road density to be an
important factor affecting sage-grouse persistence or rangewide
patterns in sage-grouse extirpation. However, the authors did not
consider the intensity of human use of roads in their modeling efforts.
They also indicated that their analyses may have been influenced by
inaccuracies in spatial road data sets, particularly for secondary
roads (Aldridge et al. 2008, p. 992). However, Wisdom et al. (in press,
p. 18) found that extirpated range has a 25 percent higher density of
roads than occupied range. Wisdom et al.'s (in press) rangewide
analysis supports the findings of numerous local studies
[[Page 13931]]
showing that roads can have both direct and indirect impacts on sage-
grouse distribution and individual fitness (e.g., Lyon and Anderson
2003, Aldridge and Boyce 2007).
Railroads
Railroads presumably have the same potential impacts to sage-grouse
as do roads because they create linear corridors within sagebrush
habitats. Railways and the cattle they transport were primarily
responsible for the initial spread of Bromus tectorum in the
intermountain region (Connelly et al. 2004, p. 7-25). B. tectorum, an
exotic species that is unsuitable as sage-grouse habitat, readily
invaded the disturbed soils adjacent to railroads. Fires created by
trains facilitated the spread of B. tectorum into adjacent areas. Knick
et al. (in press, p. 109) found that railroads cover 487 km\2\ (188
mi\2\) or less than 0.1 percent of the SGCA, but they estimated
railroads could influence 10 percent of the SGCA based adding a 3-km
(1.9-mi) buffer to estimate potential impacts from the exotic plants
they can spread. Avian collisions with trains occur, although no
estimates of mortality rates are documented in the literature (Erickson
et al. 2001, p. 8).
Summary: Habitat Conversion for Agriculture; Urbanization;
Infrastructure
Large losses of sagebrush shrub-steppe habitats due to agricultural
conversion have occurred range wide, but have been especially
significant in the Columbia Basin of Washington (MZ VI), the Snake
River Plain of Idaho (MZ IV), and the Great Plains (MZ I). Conversion
of sage brush habitats to cropland continues to occur, although
quantitative data is available only for Montana. We do not know the
current rate of conversion, but most areas suitable for agricultural
production were converted many years ago. The current rate of
conversion is likely to increase in the future if incentives for crop
production for use as biofuels continue to be offered. Urban and
exurban development also have direct and indirect negative effects on
sage-grouse, including direct and indirect habitat losses, disturbance,
and introduction of new predators and invasive plant species. Given
current trends in the Rocky Mountain west, we expect urban and exurban
development to continue. Infrastructure such as powerlines, roads,
communication towers, and fences continue to fragment sage-grouse
habitat. Past and current trends lead us to believe this source of
fragmentation will increase into the future. Fragmentation of sagebrush
habitats through a variety of mechanisms including those listed above
has been cited as a primary cause of the decline of sage-grouse
populations (Patterson 1952, pp. 192-193; Connelly and Braun 1997, p.
4; Braun 1998, p. 140; Johnson and Braun 1999, p. 78; Connelly et al.
2000a, p. 975; Miller and Eddleman 2000, p. 1; Schroeder and Baydack
2001, p. 29; Johnsgard 2002, p. 108; Aldridge and Brigham 2003, p. 25;
Beck et al. 2003, p. 203; Pedersen et al. 2003, pp. 23-24; Connelly et
al. 2004, p. 4-15; Schroeder et al. 2004, p. 368; Leu et al. in press,
p. 19). The negative effects of habitat fragmentation on sage-grouse
are diverse and include reduced lek persistence, lek attendance, winter
habitat use, recruitment, yearling annual survival, and female nest
site choice (Holloran 2005, p. 49; Aldridge and Boyce 2007, pp. 517-
523; Walker et al. 2007a, pp. 2651-2652; Doherty et al. 2008, p. 194).
Since fragmentation is associated with most anthropogenic activities,
the effects are ubiquitous across the species range (Knick et al. in
press, p. 24). We agree with the assessment that habitat fragmentation
is a primary cause of sage-grouse decline and in some areas has already
led to population extirpation. We also conclude that habitat
fragmentation will continue into the foreseeable future and will
continue to threaten the persistence of greater sage-grouse.
Fire
Many of the native vegetative species of the sagebrush-steppe
ecosystem are killed by wildfires, and recovery requires many years. As
a result of this loss of habitat, fire has been identified as a primary
factor associated with greater sage-grouse population declines (Hulet
1983, in Connelly et al. 2000a, p. 973; Crowley and Connelly 1996, in
Connelly et al. 2000c, p. 94; Connelly and Braun 1997, p. 232; Connelly
et al. 2000a, p. 973; Connelly et al. 2000c, p. 93; Miller and Eddlemen
2000, p. 24; Johnson et al., in press, p. 12; Knick and Hanser, in
press, pp. 29-30). In nesting and wintering sites, fire causes direct
loss of habitat due to reduced cover and forage (Call and Maser 1985,
p. 17). For example, prescribed fires in mountain big sagebrush at Hart
Mountain National Antelope Refuge caused a short-term increase in
certain forbs, but reduced sagebrush cover, making habitat less
suitable for nesting (Rowland and Wisdom 2002, p. 28). Similarly, Nelle
et al. (2000, p. 586) and Beck et al. (2009, p. 400) reported nesting
habitat loss from fire, creating a long-term negative impact that will
require 25 to 150 years of sagebrush regrowth before sufficient canopy
cover becomes available for nesting birds.
In southeastern Idaho, sage-grouse populations were generally
declining across the entire study area, but declines were more severe
in post-fire years (Connelly et al. 2000c, p. 93). Further, Fischer et
al. (1997, p. 89) concluded that habitat fragmentation caused by fire
may influence distribution or migratory patterns in sage-grouse. Hulet
(1983, in Connelly et al. 2000a, p. 973) documented the loss of leks
from fire.
Fire within 54 km (33.6 mi) of a lek is one of two primary factors
in predicting lek extirpation (Knick and Hanser in press, p. 26). Small
increases in the amount of burned habitat surrounding a lek had a large
influence on the probability of lek abandonment (Knick and Hanser, in
press, pp. 29-30). Additionally, fire had a negative effect on lek
trends in the Snake River Plain (MZ IV) and Southern Great Basin (MZ
III) (Johnson et al. in press, p.12). Several recent studies have
demonstrated that sagebrush area is one of the best landscape
predictors of greater sage-grouse persistence (Aldridge et al. 2008, p.
987; Doherty et al. 2008, p. 191; Wisdom et al., in press, p. 17).
While there may be limited instances where burned habitat is
beneficial, these gains are lost if sagebrush habitat is not readily
available (Woodward 2006, p. 65).
Herbaceous understory vegetation plays a critical role throughout
the breeding season as a source of forage and cover for sage-grouse
females and chicks. The response of herbaceous understory vegetation to
fire varies with differences in species composition, pre-burn site
condition, fire intensity, and pre- and post-fire patterns of
precipitation. In general, when not considering the synergistic effects
of invasive species, any short-term flush of understory grasses and
forbs is lost after only a few years and little difference is apparent
between burned and unburned sites (Cook et al. 1994, p. 298; Fischer et
al. 1996, p. 196; Crawford 1999, p. 7; Wrobleski 1999, p. 31; Nelle et
al. 2000, p. 588; Paysen et al. 2000, p. 154; Wambolt et al. 2001, p.
250). Independent of the response of perennial grasses and forbs to
fire, the most important and widespread sagebrush species for greater
sage-grouse (i.e., big sagebrush) are killed by fire and require
decades to recover. Prior to recovery, these sites are of limited to no
use to sage-grouse (Fischer et al. 1996, p. 196; Connelly et al. 2000c,
p. 90; Nelle et al. 2000, p. 588; Beck et al. 2009, p. 400). Therefore,
fire results in direct, long-term habitat loss.
In addition to altering plant community structure, fires can
influence invertebrate food sources
[[Page 13932]]
(Schroeder et al. 1999, p. 5). Ants (Hymenoptera), grasshoppers
(Orthoptera), and beetles (Coleoptera) are an essential component of
juvenile greater sage-grouse diets, especially in the first 3 weeks of
life (Johnson and Boyce 1991, p. 90). Crawford and Davis (2002, p. 56)
reported that the abundance of arthropods did not decline following
wildfire. Pyle (1992, p. 14) reported no apparent effect of prescribed
burning to beetles. However, Fischer et al. (1996, p. 197) found that
the abundance of insects was significantly lower 2-3 years post-burn.
Additionally, grasshopper abundance declined 60 percent in burned plots
versus unburned plots 1 year post-burn, but this difference disappeared
the second year (Bock and Bock 1991, p. 165). Conversely, Nelle et al.
(2000, p. 589) reported the abundance of beetles and ants was
significantly greater in 1-year-old burns, but returned to pre-burn
levels by years 3 to 5. The effect of fire on insect populations likely
varies due to a host of environmental factors. Because few studies have
been conducted and the results of those available vary, the specific
magnitude and duration of the effects of fire on insect communities is
still uncertain, as is the effect any changes may have on greater sage-
grouse populations.
The few studies that have suggested fire may be beneficial for
greater sage-grouse were primarily conducted in mesic areas used for
brood-rearing (Klebenow 1970, p. 399; Pyle and Crawford 1996, p. 323;
Gates 1983, in Connelly et al. 2000c, p. 90; Sime 1991, in Connelly et
al. 2000a, p. 972). In this habitat, small fires may maintain a
suitable habitat mosaic by reducing shrub encroachment and encouraging
understory growth. However, without available nearby sagebrush cover,
the utility of these sites is questionable. For example, Slater (2003,
p. 63) reported that sage-grouse using burned areas were rarely found
more than 60 m (200 ft) from the edge of the burn and may
preferentially use the burned and unburned edge habitat. However, Byrne
(2002, p. 27) reported avoidance of burned habitat by nesting, brood-
rearing, and broodless females. Both Connelly et al. (2000c, p. 90) and
Fischer et al. (1996, p. 196) found that prescribed burns did not
improve brood-rearing habitat in Wyoming big sagebrush, as forbs did
not increase and insect populations declined. Hence, fires in these
locations may negatively affect brood-rearing habitat rather than
improve it (Connelly and Braun 1997, p. 11).
The nature of historical fire patterns in sagebrush communities,
particularly in Artemisia tridentata var. wyomingensis, is not well
understood and a high degree of variability likely occurred (Miller and
Eddleman 2000, p. 16; Zouhar et al. 2008, p. 154; Baker in press, p.
16). However, as inferred by several lines of reasoning, fire in
sagebrush systems was historically infrequent (Baker in press, pp. 15-
16). This conclusion is evidenced by the fact that most sagebrush
species have not developed evolutionary adaptations such as re-
sprouting and heat-stimulated seed germination found in other shrub-
dominated systems, like chaparral, exposed to relatively frequent fire
events. Baker (in press, p. 17) suggests natural fire regimes and
landscapes were typically shaped by a few infrequent large fire events
that occurred at intervals approaching the historical fire rotation (50
to 350 years - see discussion below). The researcher concludes that the
historical sagebrush systems likely consisted of extensive sagebrush
habitat dotted by small areas of grassland and that this condition was
maintained by long interludes of numerous small fires, accounting for
little burned area, punctuated by large fire events that consumed large
expanses. In general, fire extensively reduces sagebrush within burned
areas, and big sagebrush varieties, the most widespread species of
sagebrush, can take up to 150 years to reestablish an area (Braun 1998,
p. 147; Cooper et al. 2007, p. 13; Lesica et al. 2007, p. 264; Baker,
in press, pp. 15-16).
Fire rotation, or the average amount of time it takes to burn once
through a particular landscape, is difficult to quantify in large
sagebrush expanses. Because sagebrush is killed by fire, it does not
record evidence of prior burns (i.e., fire scars) as do forested
systems. As a result, a clear picture of the complex spatial and
temporal pattern of historical fire regimes in most sagebrush
communities is not available. Widely variable estimates of historical
fire rotation have been described in the literature. Depending on the
species of sagebrush and other site-specific characteristics, fire
return intervals from 10 to well over 300 years have been reported
(McArthur 1994, p. 347; Peters and Bunting 1994, p. 33; Miller and Rose
1999, p. 556; Kilpatrick 2000, p. 1; Frost 1998, in Connelly et al.
2004, p. 7-4; Zouhar et al. 2008, p. 154; Baker in press, pp. 15-16).
In general, mean fire return intervals in low-lying, xeric, big
sagebrush communities range from over 100 to 350 years, and return
intervals decrease from 50 to over 200 years in more mesic areas, at
higher elevations, during wetter climatic periods, and in locations
associated with grasslands (Baker 2006, p. 181; Mensing et al. 2006, p.
75; Baker, in press, pp. 15-16; Miller et al., in press, p. 35).
The invasion of exotic annual grasses, such as Bromus tectorum and
Taeniatherum asperum (medusahead), has been shown to increase fire
frequency within the sagebrush ecosystem (Zouhar et al. 2008, p. 41;
Miller et al. in press, p. 39). B. tectorum readily invades sagebrush
communities, especially disturbed sites, and changes historical fire
patterns by providing an abundant and easily ignitable fuel source that
facilitates fire spread. While sagebrush is killed by fire and is slow
to reestablish, B. tectorum recovers within 1 to 2 years of a fire
event (Young and Evans 1978, p. 285). This annual recovery leads to a
readily burnable fuel source and ultimately a reoccurring fire cycle
that prevents sagebrush reestablishment (Eiswerth et al. 2009, p.
1324). In the Snake River Plain (MZ IV), for example, Whisenant (1990,
p. 4) suggests fire rotation due to B. tectorum establishment is now as
low as 3-5 years. It is difficult and usually ineffective to restore an
area to sagebrush after annual grasses become established (Paysen et
al. 2000, p. 154; Connelly et al. 2004, pp. 7-44 to 7-50; Pyke, in
press, p. 25). Habitat loss from fire and the subsequent invasion by
nonnative annual grasses have negatively affected sage-grouse
populations in some locations (Connelly et al. 2000c, p. 93).
Evidence exists of a significant relationship between an increase
in fire occurrence caused by Bromus tectorum invasion in the Snake
River Plain and Northern Great Basin since the 1960s (Miller et al., in
press, p. 39) and in northern Nevada and eastern Oregon since 1980 (MZs
IV and V). The extensive distribution and highly invasive nature of B.
tectorum poses substantial increased risk of fire and permanent loss of
sagebrush habitat, as areas disturbed by fire are highly susceptible to
further invasion and ultimately habitat conversion to an altered
community state. For example, Link et al. (2006, p. 116) show that risk
of fire increases from approximately 46 to 100 percent when ground
cover of B. tectorum increases from 12 to 45 percent or more. In the
Great Basin Ecoregion (defined as east-central California, most of
Nevada, and western Utah, MZs IV and V), approximately 58 percent of
sagebrush habitats are at moderate to high risk of B. tectorum invasion
during the next 30 years (Suring et al. 2005, p. 138). The BLM
estimated that approximately 11.9 million ha (29 million ac) of public
[[Page 13933]]
lands in the western distribution of the greater sage-grouse
(Washington, Oregon, Idaho, Nevada, Utah) were infested with weeds as
of 2000 (BLM 2007a, p. 3-28). The most dominant invasive plants consist
of grasses in the Bromus genus, which represent nearly 70 percent of
the total infested area (BLM 2007a, p. 3-28).
Conifer woodlands have expanded into sagebrush ecosystems over the
last century (Miller et al. in press, p. 34). Woodlands can encroach
into sagebrush communities when the interval between fires becomes long
enough for seedlings to establish and trees to mature and dominate a
site (Miller et al. in press, p. 36). However, historical fire rotation
appears to have been sufficiently long to allow woodland invasion, and
yet extensive stands of mature sagebrush were evident during settlement
times (Vale 1975, p. 33; Baker, in press, pp. 15-16). This suggests
that causes other than active fire suppression must largely explain
recent tree invasions into sagebrush habitats (Baker in press, p. 21,
24). Baker (in press, p. 24) and Miller et al. (in press, p. 37) offer
a suite of causes, acting in concert with fire exclusion that may
better explain the dramatic expansion of conifer woodlands over the
last century. These causes include alterations due to domestic
livestock grazing (such as reduced competition from native grasses and
forbs and facilitation of tree regeneration by increased shrub cover
and enhanced seed dispersal), climatic fluctuations favorable to tree
regeneration, enhanced tree growth due to increased water use
efficiency associated with carbon dioxide fertilization, and recovery
from past disturbance (both natural and anthropogenic). Regardless of
the cause of conifer woodland encroachment, the rate of expansion is
increasing and is resulting in the loss and fragmentation of sagebrush
habitats (see discussion in Pinyon-juniper section below).
Between 1980 and 2007, the number of fires and total area burned
increased in all MZs across the greater sage-grouse's range except the
Snake River Plain (MZ IV) (Miller et al., in press, p. 39).
Additionally, average fire size increased in the Southern Great Basin
(MZ III) during this same period. However, predicting the amount of
habitat that will burn during an ``average fire'' year is difficult due
to the highly variable nature of fire seasons. For example, the
approximate area burned on or adjacent to BLM-managed lands varied from
140,000 ha (346,000 ac) in 1998 to a 6-fold increase in 1999 (814,200
ha; 2 million ac) returning back down to approximately the 1998 level
in 2002 (157,700 ha; 384,743 ac) before rising again 10-fold in 2006
(1.4 million ha; 3.5 million ac) (Miller et al., in press, pp. 39-40).
From 1980 to 2007, wildfires have burned approximately 8.7 million
ha (21.5 million ac) of sagebrush, or approximately 18 percent of the
estimated 47.5 million ha (117.4 million ac) of sagebrush habitat
occurring within the delineated MZs (Baker, in press, p. 43).
Additionally, the trend in total acreage burned since 1980 has
primarily increased (Miller et al., in press, p. 39). Although fire
alters sagebrush habitats throughout the greater sage-grouse's range,
fire disproportionately affects the Great Basin (Baker et al. in press,
p. 20) (i.e., Utah, Nevada, Idaho, and eastern Oregon; MZ III, IV, and
V) and will likely influence the persistence of greater sage-grouse
populations in the area. In these three MZs combined, nearly 27 percent
of sagebrush habitat has burned since 1980 (Baker, in press, p. 43). A
primary reason for this disproportionate influence in this region is
due to the presence of burned sites and their subsequent susceptibility
to invasion by exotic annual grasses.
According to one review, range fires destroyed 30 to 40 percent of
sage-grouse habitat in southern Idaho (MZ IV) in a 5-year period (1997-
2001) (Signe Sather-Blair, BLM, in Healy 2001). This amount included
about 202,000 ha (500,000 ac), which burned between 1999 and 2001,
significantly altering the largest remaining contiguous patch of
sagebrush in the State (Signe Sather-Blair, BLM, in Healy 2001).
Between 2003 and 2007, Idaho lost an additional 267,000 ha (660,000 ac)
of sage-grouse habitat, or approximately 7 percent of the total
estimated remaining habitat in the State. Over nine fire seasons in
Nevada (1999-2007), about 1 million ha (2.5 million ac) of sagebrush
were burned, representing approximately 12 percent of the State's
extant sagebrush habitat (Espinosa and Phenix 2008, p. 3). Most of
these fires occurred in northeast Nevada (MZ IV) within quality habitat
that has traditionally supported high densities of sage-grouse, which
also is highly susceptible to Bromus tectorum invasion.
Baker (in press, p. 20) calculated recent fire rotation by MZ and
compared these to estimates of historical fire rotations. Based on this
analysis, the researcher suggests that increased fire rotations since
1980 are presumably outside the historic range of variability and far
shorter in floristic regions where Wyoming big sagebrush is common
(Baker in press, p. 20). This analysis included MZs III, IV, V, and VI,
all of which have extensive Bromus tectorum invasions.
In addition to wildfire, land managers are using prescribed fire as
well as mechanical and chemical treatments to obtain desired management
objectives for a variety of wildlife species and domestic ungulates in
sagebrush habitats throughout the range of the greater sage-grouse.
While the efficacy of treatments in sagebrush habitats to enhance sage-
grouse populations is questionable (Peterson 1970, p. 154; Swensen et
al. 1987, p. 128; Connelly et al. 2000c, p. 94; Nelle et al. 2000, p.
590; WAFWA 2009, p. 12; Connelly et al. in press c, p. 8), as with
wildland fire, an immediate and potentially long-term result is the
loss of habitat (Beck et al. 2009, p. 400).
Knick et al. (in press, p. 33) report that more than 370,000 ha
(914,000 ac) of public lands were treated with prescribed fire to
address management objectives for many different species between 1997
and 2006, mostly in Oregon and Idaho, and an additional 124,200 ha
(306,900 ac) were treated with mechanical means over this same time
period, primarily in Utah and Nevada. However, these acreages represent
all habitat types and thus overestimate negative impacts to greater
sage-grouse. Quantifying the amount of sagebrush-specific habitat
treatments is difficult due to the fact that centralized reporting is
not typically categorized by habitat. However, agencies under the
Department of the Interior (DOI) report species of special interest,
including greater sage-grouse, which may occur in proximity to a
prescribed treatment. Between 2003 and 2008, approximately 133,500 ha
(330,000 ac) of greater sage-grouse habitat have been burned by land
managers within the DOI or approximately 22,000 ha (55,000 ac)
annually. This acreage does not reflect lands burned by agencies under
the USDA (e.g., USFS). Although much of the land under USFS
jurisdiction lies outside greater sage-grouse range, this agency
manages approximately 8 percent of sagebrush habitats. Ultimately, the
amount of sagebrush habitat treated by land managers appears to
represent a relatively minor loss when compared to loss incurred by
wildfire. However, in light of the significant habitat loss due to
wildfire, and the preponderance of evidence that suggests these
treatments are not beneficial to sage-grouse, the rationale for using
such treatments to improve sage-grouse habitat deserves further
scrutiny.
Sagebrush recovery rates are highly variable, and precise estimates
are often
[[Page 13934]]
hampered by limited data from older burns. Factors contributing to the
rate of shrub recovery include the amount of and distance from unburned
habitat, abundance and viability of seed in soil seed bank (depending
on species, sagebrush seeds are typically viable for one to three
seasons), rate of seed dispersal, and pre- and post-fire weather, which
influences seedling germination and establishment (Young and Evans
1989, p. 204; Maier et al. 2001, p. 701; Ziegenhagen and Miller 2009,
p. 201). Based on a review of existing literature, Baker (in press, pp.
14-15) reports that full recovery to pre-burn conditions in Artemisia
tridentata ssp. vaseyana communities ranges between 25 and 100 years
and in A. t. ssp. wyomingensis communities between 50 and 120 years.
However, the researcher cautions that data pertaining to the latter
community is sparse. What is known is that by 25 years post-fire, A. t.
ssp. wyomingensis typically has less than 5 percent pre-fire canopy
cover (Baker in press, p. 15).
A variety of techniques have been employed to restore sagebrush
communities following a fire event (Cadwell et al. 1996, p. 143;
Quinney et al. 1996, p. 157; Livingston 1998, p. 41). The extent and
efficacy of restoration efforts is variable and complicated by
limitations in capacity (personnel, equipment, funding, seed
availability, and limited seeding window), incomplete knowledge of
appropriate methods, invasive plant species, and abiotic factors, such
as weather, that are largely outside the control of land managers
(Hemstrom et al. 2002, pp. 1250-1251; Pyke, in press, p. 29). While
post-fire rehabilitation efforts have benefited from additional
resources in recent years, resulting in an increase of treated acres
from 28,100 ha (69,436 ac) in 1997 to 1.6 million ha (3.9 million ac)
in 2002 (Connelly et al. 2004, p. 7-35), acreage treated annually
remains far outpaced by acreage disturbed. For example, of the more
than 1 million ha (2.5 million ac) of sage-grouse habitat burned during
the 2006 and 2007 fire seasons on BLM-managed lands, about 40 percent
or 384,000 ha (950,000 ac) had some form of active post-fire
restoration such as reseeding. More specifically, Eiswerth et al.
(2009, p. 1321) report that over the past 20 years within the BLM's
Winnemucca District in Nevada, approximately 12 percent of burned areas
have been actively reseeded.
The main purpose of the Burned Area Emergency Stabilization and
Rehabilitation program (BLM 2007b, pp. 1-2), designed to rehabilitate
areas following fire, is to stabilize soils and maintain site
productivity rather than to regain site suitability for wildlife (Pyke,
in press, p. 24). Consequently, in areas that experience active post-
fire restoration efforts, an emphasis is often placed on introduced
grasses that establish quickly. Only recently has a modest increase in
the use of native species for burned area rehabilitation been reported
(Richards et al. 1998, p. 630; Pyke, in press, p. 24). Further
complicating our understanding of the effectiveness of these treatments
is that most managers do not keep track of monitoring data in a routine
or systematic fashion (GAO 2003, p. 5). Assuming complete success of
restoration efforts on targeted areas, however unlikely, the return of
a shrub-dominated community will still require several decades, and
landscape restoration may require centuries or longer (Knick 1999, p.
55; Hemstrom et al. 2002, p. 1252). Even longer periods may be required
for greater sage-grouse to use recovered or restored landscapes (Knick
et al., in press, p. 65).
The loss of habitat due to wildland fire is anticipated to increase
due to the intensifying synergistic interactions among fire, people,
invasive species, and climate change (Miller et al., in press, p. 50).
The recent past- and present-day fire regimes across the greater sage-
grouse distribution have changed with a demonstrated increase in the
more arid Wyoming big sagebrush communities and a decrease across many
mountain big sagebrush communities. Both scenarios of altered fire
regimes have caused significant losses to greater sage-grouse habitat
through facilitating conifer expansion at high-elevation interfaces and
exotic weed encroachment at lower elevations (Miller et al., in press,
p. 47). In the face of climate change, both of these scenarios are
anticipated to worsen (Baker, in press, p. 24; Miller et al., in press,
p. 48). Predicted changes in temperature, precipitation, and carbon
dioxide are all anticipated to influence vegetation dynamics and alter
fire patterns resulting in the increasing loss and conversion of
sagebrush habitats (Neilson et al. 2005, p. 157). Further, many climate
scientists suggest that in addition to the predicted change in climate
toward a warmer and generally wetter Great Basin, variability of
interannual and interdecadal wet-dry cycles will increase and likely
act in concert with fire, disease, and invasive species to further
stress the sagebrush ecosystem (Neilson et al. 2005, p. 152). The
anticipated increase in suitable conditions for wildland fire will
likely further interact with people and infrastructure. Human-caused
fires have reportedly increased and been shown to be correlated with
road presence (Miller et al., in press. p. 40). Given the popularity of
off-highway vehicles (OHV) and the ready access to lands in the Great
Basin, the increasing trend in both fire ignitions by people and loss
of habitat will likely continue.
While multiple factors can influence sagebrush persistence, fire is
the primary cause of recent large-scale losses of habitat within the
Great Basin, and this stressor is anticipated to intensify. In addition
to loss of habitat and its influence on greater sage-grouse population
persistence, fragmentation and isolation of populations presents a
higher probability of extirpation in disjunct areas (Knick and Hanser,
in press, p. 20; Wisdom et al., in press, p. 22). Knick and Hanser (in
press, p. 31) suggest extinction is currently more probable than
colonization for many great sage-grouse populations because of their
low abundance and isolation coupled with fire and human influence. As
areas become isolated through disturbances such as fire, populations
are exposed to additional stressors and persistence may be hampered by
the limited ability of individuals to disperse into areas that are
otherwise not self-sustaining. Thus, while direct loss of habitat due
to fire has been shown to be a significant factor associated with
population persistence, the indirect effect posed by loss of
connectivity among populations may greatly expand the influence of this
threat beyond the physical fire perimeter.
Summary: Fire
Fire is one of the primary factors linked to population declines of
greater sage-grouse because of long-term loss of sagebrush and
conversion to monocultures of exotic grasses (Connelly and Braun 1997,
p. 7; Johnson et al., in press, p. 12; Knick and Hanser, in press, pp.
29-30). Loss of sagebrush habitat to wildfire has been increasing in
western areas of the greater sage-grouse range for the past three
decades. The change in fire frequency has been strongly influenced by
the presence of exotic annual grasses and significantly deviates from
extrapolated historical regimes. Restoration of these communities is
challenging, requires many years, and may, in fact, never be achieved
in the presence of invasive grass species. Greater sage-grouse are slow
to recolonize burned areas even if structural features of the shrub
community may have recovered (Knick et al., in press, p. 46). While it
is not currently possible to predict the extent or location of future
fire events, the best
[[Page 13935]]
scientific and commercial information available indicates that fire
frequency is likely to increase in the foreseeable future due to
increases in cover of Bromus tectorum and the projected effects of
climate change (see Invasive plants (annual grasses and other noxious
weeds), below, and also Climate Change, below).
An analysis of previously extirpated sage-grouse habitats has shown
that the extent and abundance of sagebrush habitats, proximity to
burned habitat, and degree of connectivity among sage-grouse groups
strongly affects persistence (Aldridge et al. 2008, p. 987; Knick and
Hanser, in press, pp. 29-30; Wisdom et al., in press, p. 17). The loss
of habitat caused by fire and the functional barrier burned habitat can
pose to movement and dispersal compounds the influence this stressor
can have on populations and population dynamics. Barring alterations to
the current fire pattern, as well as the difficulties associated with
restoration, the concerns presented by this threat will continue and
likely strongly influence persistence of the greater sage-grouse,
especially in the western half of its range within the foreseeable
future.
Invasive Plants (Annual Grasses and Other Noxious Weeds)
For the purposes of our analysis in this section, we consider
invasive plants (invasives) to be any nonnative plant that negatively
impacts sage-grouse habitat, including annual grasses and other noxious
weeds. However, in the literature that we reviewed, the terms noxious
weeds and invasives were not consistently defined or applied.
Consequently, both terms are used in our discussion to reflect the
original use in the sources we cite. In the source material, it was
often unclear whether discussions about noxious weeds included invasive
annual grasses (e.g., Bromus tectorum), referred solely to invasive
forbs and invasive perennial grasses, or only referenced species that
are listed on State and Federal noxious weed lists (many of which do
not consider B. tectorum a noxious weed). Nonetheless, all of these can
be categorized as nonnative plants that have a negative impact on sage-
grouse habitat and thus meet our definition of invasive plants.
Invasives alter plant community structure and composition,
productivity, nutrient cycling, and hydrology (Vitousek 1990, p. 7) and
may cause declines in native plant populations through competitive
exclusion and niche displacement, among other mechanisms (Mooney and
Cleland 2001, p. 5446). Invasive plants reduce and, in cases where
monocultures occur, eliminate vegetation that sage-grouse use for food
and cover. Invasives do not provide quality sage-grouse habitat. Sage-
grouse depend on a variety of native forbs and the insects associated
with them for chick survival, and sagebrush, which is used exclusively
throughout the winter for food and cover. Invasives impact the entire
range of sage-grouse, although not all given species are distributed
across the entire range. Leu et al. (2008, pp. 1119-1139) modeled the
risk of invasion by exotic plant species for the entire range of sage-
grouse. Areas at high risk for invasion were distributed throughout the
range, but were especially concentrated in eastern Washington (MZ VI),
southern Idaho (MZ IV), central Utah (MZ III), and northeast Montana
(MZ I).
Along with replacing or removing vegetation essential to sage-
grouse, invasives fragment existing sage-grouse habitat. They can
create long-term changes in ecosystem processes, such as fire-cycles
(see discussion under Fire above) and other disturbance regimes that
persist even after an invasive plant is removed (Zouhar et al. 2008, p.
33). A variety of nonnative annuals and perennials are invasive to
sagebrush ecosystems (Connelly et al. 2004, pp. 7-107 and 7-108; Zouhar
et al. 2008, p 144). Bromus tectorum is considered most invasive in
Artemisia tridentata ssp. wyomingensis communities, while Taeniatherum
asperum fills a similar niche in more mesic communities with heavier
clay soils (Connelly et al. 2004, p. 5-9). Some other problematic
rangeland weeds include Euphorbia esula (leafy spurge), Centaurea
solstitialis (yellow starthistle), Centaurea maculosa (spotted
knapweed), Centaurea diffusa (diffuse knapweed), and a number of other
Centaurea species (DiTomaso 2000, p. 255; Davies and Svejcar 2008, pp.
623-629).
Nonnative annual grasses (e.g., Bromus tectorum and Taeniatherum
asperum) have caused extensive sagebrush habitat loss in the
Intermountain West and Great Basin (Connelly et al. 2004, pp. 1-2 and
4-16). They impact sagebrush ecosystems by shortening fire intervals to
as low as 3 to 5 years, perpetuating their own persistence and
intensifying the role of fire (Whisenant 1990, p. 4). Connelly et al.
(2004, p. 7-5) suggested that fire intervals are shortened to less than
10 years. Although nonnative annual grasses occur throughout the sage-
grouse's range, they are more problematic in western States (MZs III,
IV, V, and VI) than Rocky Mountain States (MZs I and II) (Connelly et
al. 2004, p. 5-9).
Quantifying the total amount of sage-grouse habitat impacted by
invasives is problematic due to differing sampling methodologies,
incomplete sampling, inconsistencies in species sampled, and varying
interpretations of what constitutes an infestation (Miller et al., in
press, p. 19). Widely variable estimates of the total acreage of weed
infestations have been reported. BLM (1996, p. 6) estimated invasives
(which may or may not have included Bromus tectorum in their estimate)
covered at least 3.2 million ha (8 million ac) of BLM lands as of 1994,
and predicted 7.7 million ha (19 million ac) would be infested by 2000.
However, a qualitative 1991 BLM survey covering 40 million ha (98.8
million ac) of all BLM-managed land in Washington, Oregon, Idaho,
Nevada, and Utah (MZs III, IV, V, and VI) reported that introduced
annual grasses were a dominant or significant presence on 7 million ha
(17.2 million ac) of sagebrush ecosystems (Connelly et al. 2004, p. 5-
10). An additional 25.1 million ha (62 million ac) had less than 10
percent B. tectorum in the understory, but were considered to be at
risk of B. tectorum invasion (Zouhar 2003, p. 3, in reference to the
same survey). More recently, BLM reported that as of 2000, noxious
weeds and annual grasses occupied 11.9 million ha (29.4 million ac) of
BLM lands in Washington, Oregon, Idaho, Nevada, and Utah (BLM 2007a, p.
3-28). However, when considering all States within the current range of
sage-grouse, this number increases to 14.8 million ha (36.5 million
ac). Although estimates of the total area infested by B. tectorum vary
widely, it is clear that B. tectorum is a significant presence in
western rangelands.
The Landscape Fire and Resource Management Planning Tools Project
(LANDFIRE) has a rangewide dataset documenting annual grass
distribution. Based on 1999-2002 imagery, at least 885,990 ha (2.2
million ac) of annual grasses occur within the current range of sage-
grouse (LANDFIRE 2007). Satellite data only map annual grass
monocultures, and not areas where they occur in lower densities or even
dominate the sagebrush understory (which is mapped as sagebrush).
Therefore, the LANDFIRE dataset is a gross underestimate of the total
acres of infestation. However, this dataset provides a rangewide
comparison of annual grass monocultures and identifies the large extent
of these monocultures in both the western and eastern part of the sage-
grouse's range.
[[Page 13936]]
Approximately 80 percent of land in the Great Basin Ecoregion (MZs
III, IV, and V) is susceptible to displacement by Bromus tectorum
(including over 58 percent of sagebrush that is moderately or highly
susceptible) within 30 years (Connelly et al. 2004, p. 7-17, Suring et
al. 2005, p. 138). Due to the disproportionate abundance of B. tectorum
in the Great Basin, suggesting an increased susceptibility to B.
tectorum invasion than other parts of the sage-grouse's range, Connelly
et al. (2004, p. 7-8) cautioned that a formal analysis of the risk of
B. tectorum invasion in other areas was needed before such inferences
are made. Also, while nonnative annual grasses are usually associated
with lower elevations and drier climates (Connelly et al. 2004, p. 5-
5), the ecological range of B. tectorum continues to expand at low and
high elevations (Ramakrishnan et al. 2006, pp. 61-62), both southward
and eastward (Miller et al., in press, p. 21). Local infestations of B.
tectorum and other annual grasses occur in Montana, Wyoming, and
Colorado (MZs I and II) (Miller et al., in press, p. 21), and there is
evidence that B. tectorum is impacting fire intervals in Wyoming. For
example, 40,469 ha (100,000 ac) of sagebrush that burned in a wildfire
southeast of Worland, Wyoming (MZ II), became infested with B.
tectorum, accelerating the fire interval in this area (Wyoming Big Horn
Basin Sage-grouse Local Working Group 2007, pp. 39-40).
Noxious weeds spread about 931 ha (2,300 ac) per day on BLM land
and 1,862 ha (4,600 ac) per day on all public land in the West (BLM
1996, p. 1), or increase about 8 to 20 percent annually (Federal
Interagency Committee for the Management of Noxious and Exotic Weeds
1997, p. v). Invasions are often associated with ground disturbances
caused by wildfire, grazing, infrastructure, and other anthropogenic
activity (Rice and Mack 1990, p. 84; Gelbard and Belnap 2003, p. 420;
Zouhar et al. 2008, p. 23), but disturbance is not required for
invasives to spread (Young and Allen 1997, p. 531; Roundy et al. 2007,
p. 614). Invasions also may occur sequentially, where initial invaders
(e.g., Bromus tectorum) are replaced by new exotics (Crawford et al.
2004, p 9; Miller et al., in press, p. 20).
Based on data collected in the western half of the range, Bradley
et al. (2009, pp. 1511-1521; Bradley 2009, pp. 196-208) predicted
favorable conditions for Bromus tectorum across much of the sage-
grouse's range under current and future (2100) climate conditions. A
strong indicator for future B. tectorum locations is the proximity to
current locations (Bradley and Mustard 2006, p. 1146) as well as
summer, annual, and spring precipitation, and winter temperature
(Bradley 2009, p. 196). Bradley et al. (2009, p. 1517) predicted that
in the future some areas will become unfavorable for B. tectorum while
others will become favorable. Specifically, Bradley et al. (2009, p.
1515) predicted that climatically suitable B. tectorum habitat will
shift northwards, leading to expanded risk in Idaho, Montana, and
Wyoming, but reduced risk in southern Nevada and Utah. Despite the
potential for future retreat in Nevada and Utah, there will still be
climatically suitable B. tectorum habitat in these States, well within
the range of sage-grouse (see Figure 4b in Bradley et al. 2009, p.
1517). Bradley et al. (2009, p. 1511) noted that changes in climatic
suitability may create restoration opportunities in areas that are
currently dominated by invasives. We anticipate that B. tectorum will
eventually disappear from areas that become climatically unsuitable for
this species, but this transition is unlikely to occur suddenly. Also,
Bradley et al. (2009, p. 1519) cautioned that areas that become
unfavorable to B. tectorum may become favorable to other invasives,
such as B. rubens (red brome) in the southern Great Basin, which is
more tolerant of higher temperatures. Therefore, areas that become
unsuitable for B. tectorum will not necessarily be returned to pre-
invaded habitat conditions without significant effort. Bradley et al.
(2009, p. 1519) suggested that modeling and experimental work is needed
to assess whether native species could occupy these sites if invasives
are reduced or eliminated by climate change.
LANDFIRE also has a rangewide dataset documenting other exotic
grasses and forbs, including perennial grasses and annual, perennial,
and biennial forbs. Like annual grasses, other invasive plants are
grossly underestimated in the LANDFIRE dataset because the dataset only
includes monocultures of these species. Based on 1999-2002 imagery, at
least 1.3 million ha (3.3 million ac) of other exotic plants occur
within the current range of sage-grouse (LANDFIRE 2007). Aside from
LANDFIRE, the only other information documenting the specific
distribution of invasives within the sage-grouse's range is at a
presence-absence scale at the county level. DiTomaso (2000, p. 257)
estimated that western rangelands are infested with 2,900,000 ha
(7,166,027 ac) of C. maculosa, 1,300,000 ha (3,212,357 ac) of C.
diffusa, 8,000,000 ha (19,768,352 ac) of C. solstitialis, and 1,100,000
ha (2,718,148 ac) of Euphorbia esula, but this estimate did not
describe the distribution of invasives across the landscape. These
estimates, combined with estimates of acres infested by Bromus
tectorum, and the fact that LANDFIRE detected more acres of other
noxious weeds than annual grasses, illustrate the severity of the
invasives problem.
Invasives that are not annual grasses impact the entire range of
sage-grouse, although not all given species are distributed across the
entire range. Leu et al. (2008, pp. 1119-1139) modeled the risk of
invasion by exotic plant species (which also would include annual
grasses), for the entire range of sage-grouse. Areas at high risk for
invasion were distributed throughout the range, but were especially
concentrated in eastern Washington (MZ VI), southern Idaho (MZ IV),
central Utah (MZ III), and northeastern Montana (MZ I). Like Bromus
tectorum, the distribution of other invasives will likely shift with
climate change. Bradley et al. (2009, p. 1518) predicts that the range
of C. maculosa will expand in some areas, mainly in parts of Oregon,
Idaho, western Wyoming, and Colorado, and will contract in other areas
(e.g., eastern Montana). She also predicts that the range of C.
solstitialis will expand eastward (Bradley et al. 2009, p. 1514) and
that the invasion risk of Euphorbia esula will likely decrease in
several States, including parts of Colorado, Oregon, and Idaho (Bradley
et al. 2009, pp. 1516-1518).
Many efforts are ongoing to restore or rehabilitate sage-grouse
habitat affected by invasive species. Common rehabilitation techniques
include first reducing the density of invasives using herbicides,
defoliation via grazing, pathogenic bacteria and other forms of
biocontrol, or prescribed fire (Tu et al. 2001; Larson et al. 2008, p.
250; Pyke, in press, pp. 25-26). Sites are then typically reseeded with
grass and forb mixes, and sometimes planted with sagebrush plugs.
Despite ongoing efforts to transform lands dominated by invasive annual
grasses into quality sage-grouse habitat, restoration and
rehabilitation techniques are considered to be mostly unproven and
experimental (Pyke, in press, pp. 25-28, and see discussion on fire
above).
Several components of the restoration process are being
investigated with varying success (Pyke, in press, p. 25). Some
techniques show promise, such as use of the herbicide Imazapic to
control Bromus tectorum. However, further analyses of the benefit of
this method still need to be conducted (Pyke, in
[[Page 13937]]
press, p. 27). Also, it will take time for sagebrush to establish and
mature in areas currently dominated by annual grasses. Rehabilitation
and restoration efforts also are hindered by cost and the ability to
procure the equipment and seed needed for projects (Pyke, in press, pp.
29-30). Furthermore, while restoration projects for other species may
depend on a single site or landowner, restoration of sage-grouse
habitat requires partnerships across multiple ownerships in order to
restore and maintain a connective network of intact vegetation (Pyke,
in press, pp. 33-34).
Treatment success also depends on factors which are not
controllable, such as precipitation received at the treatment site
(Pyke, in press, p. 30). For example, only 3.3 to 33.6 percent of
recent vegetation treatments conducted by the BLM in annual grassland
monocultures were reported as successful (Carlson 2008b, pers. comm.).
Areas with established annual grasses that receive less than 22.9 cm (9
in.) of annual precipitation are less likely to benefit from
restoration (Connelly et al. 2004, p. 7-17, Carlson 2008b, pers.
comm.). Consequently, BLM focuses most (98 percent) of their
restoration efforts in areas receiving more than 22.9 cm (9 in.) of
annual precipitation where there is greater chance of success. Of the
BLM treatments in annual grasslands, only 10 percent of acres treated
in areas receiving less than 22.9 cm (9 in.) of annual precipitation
were considered to be effectively treated. In areas receiving between
22.9 cm (9 in.) and 30.5 cm (12 in.) of annual precipitation, 33.6
percent of the acres were treated effectively, and 3.3 percent of the
acres were treated effectively in areas receiving greater than 30.5 cm
(12 in.) of annual precipitation (Carlson 2008b, pers. comm.). Since
the BLM treatments in annual grassland monocultures included both the
reestablishment of native shrub and grass species and greenstripping
efforts to reduce the frequency of fires in annual grassland
monocultures, it is unclear how many of these successfully treated
acres are attributed to restoration versus prevention.
A variety of regulatory mechanisms and nonregulatory measures to
control invasive plants exist. However, the extent to which these
mechanisms effectively ameliorate the current rate of invasive
expansion is unclear. If noxious weeds are spreading at a rate of 931
ha (2,300 ac) per day on BLM lands (BLM 1996, p. 1), this amounts to
339,815 ha (839,500 ac) per year, which includes both suitable and
nonsuitable habitat for sage-grouse. It is unclear whether this
estimate is limited to noxious weeds or if it includes other invasives
(e.g., Bromus tectorum). Still, we can compare this estimate to the
area of all invasives (excluding conifers) treated by the BLM between
October 2005 and September 2007, which totaled 259,897 ha (642,216 ac),
i.e., approximately 86,632 ha (214,072 ac) treated annually.
The number of acres treated annually (86,632 ha; 214,072 ac) is not
keeping pace with the rate of spread (339,815 ha; 839,500 ac)
especially when considering the inability to treat the problem. We
acknowledge that the rate of spread on BLM lands also includes areas
that are not sage-grouse habitat. However, the rate of spread may not
have included B. tectorum and only part of the invasive treatments
completed by BLM (23.6 percent of treatments in annual grassland
monocultures and 7.5 percent of treatments in sagebrush with annual
grassland understories) were considered to be effective by the BLM
(Carlson 2008b, pers. comm.). Also, treatments are typically considered
to be successful based on whether native vegetation was reestablished,
maintained, or enhanced, and not based on a positive population
response of sage-grouse to the treatment. Therefore, the effectiveness
of treatments for sage-grouse is likely much less than reported for
vegetation.
The National Invasive Species Council (2008, p. 8) acknowledges
that there has been a significant increase in activity and awareness,
but that much remains to be done to prevent and mitigate the problems
caused by invasive species. As an example, the State of Montana has
made much progress through partnerships in reducing noxious weeds in
the State from 3.2 million ha (8 million ac) in 2000 to 3.1 million ha
(7.6 million ac) in 2008 (Montana Weed Control Association 2008).
However, the Montana Noxious Weed Summit Advisory Council Weed
Management Task Force (2008, p. III) estimates that to slow weed spread
and reduce current infestations by 5 percent annually, they require 2.6
times the current level of funding from a variety of private, local,
State, and Federal sources (or $55.8 million versus $21.2 million). In
addition to funding, other factors that potentially limit ability to
control invasives include the amount of available native seed sources,
the time it takes to restore sagebrush to an area once it is removed
from a site, and the existence of treatments that are known to be
effective in the long-term. Monitoring is limited in many cases and,
where it occurs, monitoring typically does not document the population
response of sage-grouse to these treatments.
Invasives are a serious rangewide threat, and one of the highest
risk factors for sage-grouse based on the plants' ability to out-
compete sagebrush, the inability to effectively control them once they
become established, and the synergistic interaction between them and
other risk factors on the landscape (e.g., wildfire, infrastructure
construction). Invasives reduce and eliminate vegetation that is
essential for sage-grouse to use as food and cover. Their presence on
the landscape has removed and fragmented sage-grouse habitat. Because
invasives are widespread, have the ability to spread rapidly, occur
near areas susceptible to invasion, and are difficult to control, we
anticipate that invasives will continue to replace and reduce the
quality of sage-grouse habitat across the range in the foreseeable
future. There have been many studies addressing effective invasive
control methods, as well as conservation actions to control invasives,
with varied success. While some efforts appear successful at smaller
scales, prevention (e.g., early detection and fire prevention) appears
to be the only known effective tool to preclude or minimize large-scale
habitat loss from invasive species in the future.
Pinyon-Juniper Encroachment
Pinyon-juniper woodlands are a native habitat type dominated by
pinyon pine (Pinus edulis) and various juniper species (Juniperus spp.)
that can encroach upon, infill, and eventually replace sagebrush
habitat. These two woodland types are often referred to collectively as
pinyon-juniper; however, some portions of the sage-grouse's range are
only impacted by juniper encroachment. Commons et al. (1999, p. 238)
found that the number of male Gunnison sage-grouse (C. minimus) on leks
in southwestern Colorado doubled after pinyon-juniper removal and
mechanical treatment of mountain sagebrush and deciduous brush. Hence,
we infer that some greater sage-grouse populations have been negatively
affected by pinyon-juniper encroachment and that some populations will
decline in the future due to projected increases in the pinyon-juniper
type, especially in areas where pinyon-juniper encroachment is a large-
scale threat (parts of MZs III, IV, and V). Doherty et al. (2008, p.
187) reported a strong avoidance of conifers by female greater sage-
grouse in the winter, further supporting our previous inference. Also,
Freese's (2009, pp. 84-85, 89-90) 2-year telemetry study in central
Oregon found that sage-grouse
[[Page 13938]]
used areas with less than 5 percent juniper cover more often in the
breeding and summer seasons than similar habitat that had greater than
5 percent juniper cover. Therefore, pinyon-juniper encroachment into
occupied sage-grouse habitat reduces, and likely eventually eliminates,
sage-grouse occupancy in these areas.
Pinyon-juniper woodlands are often associated with sagebrush
communities and currently occupy at least 18 million ha (44.6 million
ac) of the Intermountain West within the sage-grouse's range (Crawford
et al. 2004, p. 8; Miller et al. 2008, p. 1). Pinyon-juniper extent has
increased 10-fold in the Intermountain West since European settlement
causing the loss of many bunchgrass and sagebrush-bunchgrass
communities (Miller and Tausch 2001, pp. 15-16). This expansion has
been attributed to the reduced role of fire, the introduction of
livestock grazing, increases in global carbon dioxide concentrations,
climate change, and natural recovery from past disturbance (Miller and
Rose 1999, pp. 555-556; Miller and Tausch 2001, p. 15; Baker, in press,
p. 24; see also discussion under Fire above).
Connelly et al. (2004, pp. 7-8 to 7-14) estimated that
approximately 60 percent of sagebrush in the Great Basin was at low
risk of displacement by pinyon-juniper in 30 years, 6 percent at
moderate risk, and 35 percent at high risk. Mountain big sagebrush
appears to be most at risk of pinyon-juniper displacement (Connelly et
al. 2004, pp. 7-13). When juniper increases in mountain big sagebrush
communities, shrub cover declines and the season of available succulent
forbs is shortened due to soil moisture depletion (Crawford et al.
2004, p. 8). As with Bromus tectorum, the Great Basin appears more
susceptible to pinyon-juniper invasion than other areas of the sage-
grouse's range; however, Connelly et al. (2004, pp. 7-8) cautioned that
a formal analysis of the risks posed in other locations was needed
before such inferences could be made.
Annual encroachment rates that were reported in five studies ranged
from 0.3 to 31 trees per hectare (0.7 to 77 trees per acre) (Sankey and
Germino 2008, p. 413). For the three studies that measured the percent
increase in juniper cover per year, cover increased between 0.4 and 4.5
percent annually (Sankey and Germino 2008, p. 413). Sankey and Germino
(2008, p. 413) compared juniper encroachment rates from previous
research to their study. Their estimate that juniper cover increased
0.7 to 1.5 percent annually was based on a 22 to 30 percent increase in
cover between 1985 and 2005 at their southeastern Idaho study site
(Sankey and Germino 2008, pp. 412-413).
Pinyon-juniper expansion into sagebrush habitats, with subsequent
replacement of sagebrush communities, has been well documented (Miller
et al. 2000, p. 575; Connelly et al. 2004, p. 7-5; Crawford et al.
2004, p. 2; Miller et al. 2008, p. 1). However, few studies have
documented woodland dynamics at the landscape level across different
ecological provinces, creating some uncertainty regarding the total
amount of expansion that has occurred in sagebrush communities (Miller
et al. 2008, p. 1). Regardless, we know that up to 90 percent of
existing woodlands in the sagebrush-steppe and Great Basin sagebrush
vegetation types were previously dominated by sagebrush vegetation
prior to the late 1800s (Miller et al., in press, pp. 23-24). Based on
past trends and the current distribution of pinyon-juniper relative to
sagebrush habitat, we anticipate that expansion will continue at
varying rates across the landscape and cause further loss of sagebrush
habitat within the western part of the sage-grouse's range, especially
in parts of MZs III, IV, and V.
While pinyon-juniper expansion appears less problematic in the
eastern portion of the range (MZs I, II and VII) and silver sagebrush
areas (primarily MZ I), woodland encroachment is a threat mentioned in
Wyoming, Montana, and Colorado State sage-grouse conservation plans,
indicating that this is of some concern in these States as well (Stiver
et al. 2006, p. 2-23). Colorado's State plan mapped areas threatened by
pinyon-juniper encroachment in northwestern Colorado, and specifically
attributed some sage-grouse habitat loss in Colorado to pinyon-juniper
expansion (Colorado Greater Sage-grouse Steering Committee 2008, pp.
179, 182). Furthermore, LANDFIRE (2007) data illustrates extensive
coverage of pinyon-juniper woodlands in parts of northwestern Colorado
within the range of sage-grouse. These data also show limited pinyon-
juniper coverage in Montana and Wyoming; however, LANDFIRE data could
be a major underestimate of juniper because it is difficult to classify
pinyon-juniper woodlands with satellite imagery when the trees occur at
low densities (Hagen 2005, p. 142).
Recently, many conservation actions have addressed this threat
using a variety of techniques (e.g., mechanical, herbicide, cutting,
burning) to remove conifers in sage-grouse habitat. The effectiveness
of these treatments varies with the technique used and proximity of the
site to invasive plant infestations, among other factors. We are not
aware of any study documenting a direct correlation between these
treatments and increased greater sage-grouse productivity; however, we
infer some level of positive response based on Commons et al.'s (1999)
Gunnison sage-grouse study and the documented avoidance, or reduced
use, by sage-grouse of areas where pinyon-juniper has encroached upon
sagebrush communities (Doherty et al. 2008, p. 187; Freese 2009, pp.
84-85, 89-90). However, since the effectiveness of treatments for sage-
grouse is usually based on a short-term, anecdotal evaluation of
whether pinyon-juniper was successfully removed from a site, it is
unclear whether pinyon-juniper removal has a positive long-term
population-level impact for sage-grouse. In most cases it is still too
early to measure a population response to these treatments (Oregon
Department of Fish and Wildlife (ODFW) 2008, p. 3). Consequently, we do
not know if these efforts are effectively ameliorating the threat of
pinyon-juniper expansion at the site-level.
Furthermore, while many acres have been treated since 2004,
treatments are not likely keeping pace with the current rate of pinyon-
juniper encroachment, at least in parts of the range. For example,
while Oregon has treated approximately 8,094 ha (20,000 ac) of juniper
to restore native sagebrush habitat between 2003 and early 2008 (about
1,619 ha or 4,000 ac per year; ODFW 2008, p. 3), LANDFIRE data show at
least 106,882 ha (264,110 ac) of juniper occur within 4.8 km (3 mi) of
Oregon leks. This distance (4.8 km; 3 mi) reflects the upper estimate
of a typical pinyon seed dispersal event, although seeds may be
dispersed shorter distances and up to at least 10 km (6.2 mi) (Chambers
et al. 1999, p. 12). At this rate, it would take approximately 60 years
to remove the threat of juniper encroachment within 3 miles of sage-
grouse leks in Oregon, assuming expansion does not continue.
Again, LANDFIRE data provides a gross underestimate of pinyon-
juniper since it misses single, large trees. This underestimate
suggests that it will take longer than 60 years to fully address the
threat of juniper encroachment in Oregon, if conservation actions
continue to occur at the current rate. Furthermore, not all treatments
are effective. Of the 38,780 ha (95,826 ac) treated by BLM in Fiscal
Year (FY) 2006 and FY 2007, only 21,598 ha (53,369 ac), or 55.7 percent
were considered to be effective by the BLM (Carlson 2008b, pers.
comm.). Again, the measure of effectiveness typically refers to whether
[[Page 13939]]
vegetation was treated successfully, and not whether sage-grouse use an
area that has been treated.
Summary: Invasive Plants and Pinyon-Juniper Encroachment
Invasives plants negatively impact sage-grouse primarily by
reducing or eliminating native vegetation that sage-grouse require for
food and cover, resulting in habitat loss and fragmentation. A variety
of nonnative annuals and perennials (e.g., Bromus tectorum, Euphorbia
esula) and native conifers (e.g., pinyon pine, juniper species) are
invasive to sagebrush ecosystems. Nonnative invasives, including annual
grasses and other noxious weeds, continue to expand their range,
facilitated by ground disturbances such as wildfire, grazing, and
infrastructure. Pinyon and juniper and some other native conifers are
expanding and infilling their current range mainly due to decreased
fire return intervals, livestock grazing, and increases in global
carbon dioxide concentrations associated with climate change, among
other factors.
Collectively, invasives plants impact the entire range of sage-
grouse, although they are most problematic in the Intermountain West
and Great Basin (MZs III, IV, V, and VI). A large portion of the Great
Basin is at risk of B. tectorum invasion or pinyon-juniper encroachment
within the next 30 years. Approximately 80 percent of land in the Great
Basin Ecoregion (MZs III, IV, and V) is susceptible to displacement by
B. tectorum within 30 years (Connelly et al. 2004, p. 7-17, Suring et
al. 2005, p. 138). Connelly et al. (2004, pp. 7-8 to 7-14) estimated
that approximately 35 percent of sagebrush in the Great Basin was at
high risk of displacement by pinyon-juniper in 30 years. Bromus
tectorum is widespread at lower elevations and pinyon-juniper woodlands
tend to expand into higher elevation sagebrush habitats, creating an
elevational squeeze from both low and high elevations. Climate change
will likely alter the range of individual invasive species, increasing
fragmentation and habitat loss of sagebrush communities. Despite the
potential shifting of individual species, invasive plants will persist
and continue to spread rangewide in the foreseeable future.
A variety of restoration and rehabilitation techniques are used to
treat invasive plants, but they can be costly and are mostly unproven
and experimental. The success of treatments, particularly for annual
grassland restoration, depends on uncontrollable factors (e.g.,
precipitation). While some efforts appear successful at smaller scales,
prevention appears to be the only known effective tool to preclude
large-scale habitat loss from invasive annuals and perennials in the
future. Pinyon-juniper treatments, particularly when done in the early
stages of encroachment when sagebrush and forb understory is still
intact, have the potential to provide an immediate benefit to sage-
grouse. However, studies have not yet documented a correlation between
pinyon-juniper treatments and increased greater sage-grouse
productivity.
Grazing
Native herbivores, such as pronghorn antelope (Antilocapra
americana), mule deer (Odocoileus hemionus), bison (Bison bison), and
other ungulates were present in low numbers on the sagebrush-steppe
region prior to European settlement of western States (Osborne 1953, p.
267; Miller et al. 1994, p. 111), and sage-grouse co-evolved with these
animals. However, mass extinction of the majority of large herbivores
occurred 10,000 to 12,000 years ago (Knick et al. 2003, p. 616; Knick
et al., in press, p. 40). From that period up until European
settlement, many areas of sagebrush-steppe still did not support herds
of large ungulates and grazing pressure was likely sporadic and
localized (Miller et al. 1994, p. 113; Plew and Sundell 2000, p. 132;
Grayson 2006, p. 921). Additionally, plants of the sagebrush-steppe
lack traits that reflect a history of large ungulate grazing pressure
(Mack and Thompson 1982, pp. 757). Therefore, native vegetation
communities within the sagebrush ecosystem evolved in the absence of
significant grazing presence (Mack and Thompson 1982, p. 768). With
European settlement of western States (1860 to the early 1900s),
unregulated numbers of cattle, sheep, and horses rapidly increased,
peaking at the turn of the century (Oliphant 1968, p. vii; Young et al.
1976, pp. 194-195, Carpenter 1981, p. 106; Donahue 1999, p. 15) with an
estimated 19.6 million cattle and 25 million sheep in the West (BLM
2009a, p. 1).
Excessive grazing by domestic livestock during the late 1800s and
early 1900s, along with severe drought, significantly impacted
sagebrush ecosystems (Knick et al. 2003, p. 616). Long-term effects
from this overgrazing, including changes in plant communities and
soils, persist today (Knick et al. 2003, p.116). Currently, livestock
grazing is the most widespread type of land use across the sagebrush
biome (Connelly et al. 2004, p. 7-29); almost all sagebrush areas are
managed for livestock grazing (Knick et al. 2003, p. 616; Knick et al.,
in press, p. 27).
Although little direct experimental evidence links grazing
practices to population levels of greater sage-grouse (Braun 1987, p.
137; Connelly and Braun 1997, p. 231), the impacts of livestock grazing
on sage-grouse habitat and on some aspects of the life cycle of the
species have been studied. Sage-grouse need significant grass and shrub
cover for protection from predators, particularly during nesting
season, and females will preferentially choose nesting sites based on
these qualities (Hagen et al. 2007, p. 46). The reduction of grass
heights due to livestock grazing in sage-grouse nesting and brood-
rearing areas has been shown to negatively affect nesting success when
cover is reduced below the 18 cm (7 in.) needed for predator avoidance
(Gregg et al. 1994, p. 165). Based on measurements of cattle foraging
rates on bunchgrasses both between and under sagebrush canopies, the
probability of foraging on under-canopy bunchgrasses depends on
sagebrush morphology, and consequently, the effects of grazing on
nesting habitats might be site specific (France et al. 2008, pp. 392-
393).
Several authors have noted that grazing by livestock could reduce
the suitability of breeding and brood-rearing habitat, negatively
affecting sage-grouse populations (Braun 1987, p. 137; Dobkin 1995, p.
18; Connelly and Braun 1997, p. 231; Beck and Mitchell 2000, pp. 998-
1000). Exclosure studies have demonstrated that domestic livestock
grazing reduces water infiltration rates and cover of herbaceous plants
and litter, as well as compacting soils and increasing soil erosion
(Braun 1998, p. 147; Dobkin et al. 1998, p. 213). These impacts result
in a change in the proportion of shrub, grass, and forb components in
the affected area, and an increased invasion of exotic plant species
that do not provide suitable habitat for sage-grouse (Mack and Thompson
1982, p. 761; Miller and Eddleman 2000, p. 19; Knick et al., in press,
p. 41).
Livestock also may compete directly with sage-grouse for rangeland
resources. Cattle are grazers, feeding mostly on grasses, but they will
make seasonal use of forbs and shrub species like sagebrush (Vallentine
1990, p. 226). Domestic sheep are intermediate feeders making high use
of forbs, but also using a large volume of grass and shrub species like
sagebrush (Vallentine 1990, pp. 240-241). Sheep consume rangeland forbs
in occupied sage-grouse habitat (Pederson et al. 2003, p. 43) and, in
general, forb consumption may reduce food availability for sage-grouse.
This
[[Page 13940]]
impact is particularly important for pre-laying hens, as forbs provide
essential calcium, phosphorus, and protein (Barnett and Crawford 1994,
p. 117). A hen's nutritional condition affects nest initiation rate,
clutch size, and subsequent reproductive success (Barnett and Crawford
1994, p.117; Coggins 1998, p. 30).
Other effects of direct competition between livestock and sage-
grouse depend on condition of the habitat and the grazing practices.
Thus, the effects vary across the range of the greater sage-grouse. For
example, Aldridge and Brigham (2003, p. 30) suggest that poor livestock
management in mesic sites, which are considered limited habitats for
sage-grouse in Alberta (Aldridge and Brigham 2002, p. 441), results in
a reduction of forbs and grasses available to sage-grouse chicks,
thereby affecting chick survival.
Other consequences of grazing include several related to livestock
trampling of grouse and habitat. Although the effect of trampling at a
population level is unknown, outright nest destruction has been
documented and the presence of livestock can cause sage-grouse to
abandon their nests (Rasmussen and Griner 1938, p. 863; Patterson 1952,
p. 111; Call and Maser 1985, p. 17; Holloran and Anderson 2003, p. 309;
Coates 2007, p.28). Coates (2007, p. 28) documented nest abandonment
following partial nest depredation by a cow. In general all recorded
encounters between livestock and grouse nests resulted in hens flushing
from nests, which could expose the eggs to predation; there is strong
evidence that visual predators like ravens use hen movements to locate
sage-grouse nests (Coates 2007, p.33). Livestock also may trample
sagebrush seedlings, thereby removing a source of future sage-grouse
food and cover (Connelly et al. 2004, p. 7-31). Trampling of soil by
livestock can reduce or eliminate biological soil crusts making these
areas susceptible to Bromus tectorum invasion (Mack 1981 as cited in
Miller and Eddleman 2000, p. 21; Young and Allen 1997, p. 531).
Some livestock grazing effects may have positive consequences for
sage-grouse. Evans (1986, p. 67) found that sage-grouse used grazed
meadows significantly more during late summer than ungrazed meadows
because grazing had stimulated the regrowth of forbs. Klebenow (1981,
p. 121) noted that sage-grouse sought out and used openings in meadows
created by cattle grazing in northern Nevada. Also, both sheep and
goats have been used to control invasive weeds (Mosley 1996 as cited in
Connelly et al. 2004, p. 7-49; Merritt et al. 2001, p. 4; Olsen and
Wallander 2001, p. 30) and woody plant encroachment (Riggs and Urness
1989, p. 358) in sage-grouse habitat.
Sagebrush plant communities are not adapted to domestic grazing
disturbance. Grazing changed the functioning of systems into less
resilient, and in some cases, altered communities (Knick et al., in
press, p. 39). The ability to restore or rehabilitate areas depends on
the condition of the area relative to its site potential (Knick et al.,
in press, p. 39). For example, if an area has a balanced mix of shrubs
and native understory vegetation, a change in grazing management can
restore the habitat to its potential vigor (Pyke, in press, p. 11).
Wambolt and Payne (1986, p. 318) found that rest from grazing had a
better perennial grass response than other treatments. Active
restoration would be required where native understory vegetation is
much reduced (Pyke, in press, p. 15). But, if an area has soil loss
and/or invasive species, returning the site to the native historical
plant community may be impossible (Daubenmire 1970, p. 82; Knick et
al., in press, p. 39; Pyke, in press, p. 17). Aldridge et al. (2008, p.
990) did not find any relationship between sage-grouse persistence and
livestock densities. However, the authors noted that livestock numbers
do not necessarily correlate with range condition. They concluded that
the intensity, duration, and distribution of livestock grazing are more
influential on rangeland condition than the livestock density values
used in their modeling efforts (Aldridge et al. 2008, p. 990).
Extensive rangeland treatment has been conducted by federal
agencies and private landowners to improve conditions for livestock in
the sagebrush-steppe region (Connelly et al. 2004, p. 7- 28; Knick et
al., in press, p. 28). By the 1970s, over 2 million ha (5 million ac)
of sagebrush are estimated to have been mechanically treated, sprayed
with herbicide, or burned in an effort to remove sagebrush and increase
herbaceous forage and grasses (Crawford et al. 2004, p. 12). The BLM
treated over 1,800,000 ha (4,447,897 ac) from 1940 to 1994, with 62
percent of the treatment occurring during the 1960s (Miller and
Eddleman 2000, p. 20). Braun (1998, p. 146) concluded that, since
European settlement of western North America, all sagebrush habitats
used by greater sage-grouse have been treated in some way to reduce
shrub cover. The use of chemicals to control sagebrush was initiated in
the 1940s and intensified in the 1960s and early 1970s (Braun 1987, p.
138). Crawford et al. (2004, p. 12) hypothesized that reductions in
sage-grouse habitat quality (and possibly sage-grouse numbers) in the
1970s may have been associated with extensive rangeland treatments to
increase forage for domestic livestock.
Greater sage-grouse response to herbicide treatments depends on the
extent to which forbs and sagebrush are killed. Chemical control of
sagebrush has resulted in declines of sage-grouse breeding populations
through the loss of live sagebrush cover (Connelly et al. 2000a, p.
972). Herbicide treatment also can result in sage-grouse emigration
from affected areas (Connelly et al. 2000a, p. 973), and has been
documented to have a negative effect on nesting, brood carrying
capacity (Klebenow 1970, p. 399), and winter shrub cover essential for
food and thermal cover (Pyrah 1972 and Higby 1969 as cited in Connelly
et al. 2000a, p. 973). Conversely, small treatments interspersed with
nontreated sagebrush habitats did not affect sage-grouse use,
presumably due to minimal effects on food or cover (Braun 1998, p.
147). Also, application of herbicides in early spring to reduce
sagebrush cover may enhance some brood-rearing habitats by increasing
the coverage of herbaceous plant foods (Autenrieth 1981, p. 65).
Mechanical treatments are designed to either remove the aboveground
portion of the sagebrush plant (mowing, roller chopping, and roto-
beating), or to uproot the plant from the soil (grubbing, bulldozing,
anchor chaining, cabling, railing, raking, and plowing; Connelly et al.
2004, p. l7-47). These treatments were begun in the 1930s and continued
at relatively low levels to the late 1990s (Braun 1998, p. 147).
Mechanical treatments, if carefully designed and executed, can be
beneficial to sage-grouse by improving herbaceous cover, forb
production, and sagebrush resprouting (Braun 1998, p. 147). However,
adverse effects also have been documented (Connelly et al. 2000a, p.
973). For example, in Montana, the number of breeding males declined by
73 percent after 16 percent of the 202-km\2\ (78- mi\2\) study area was
plowed (Swenson et al. 1987, p. 128). Mechanical treatments in blocks
greater than 100 ha (247 ac), or of any size seeded with exotic
grasses, degrade sage-grouse habitat by altering the structure and
composition of the vegetative community (Braun 1998, p. 147).
The current extent to which mechanical, chemical, and prescribed
fire methods are used to remove or control sagebrush is not known,
particularly with regard to private lands. However, BLM has stated that
with rare exceptions, they no longer are involved
[[Page 13941]]
in actions that convert sagebrush to other habitat types, and that
mechanical or chemical treatments in sagebrush habitat on BLM lands
currently focus on improving the diversity of the native plant
community, reducing conifer encroachment, or reducing the risk of a
large wildfire (see discussion of Fire above; BLM 2004, p. 15).
Historically, the elimination of sagebrush followed with rangeland
seedings was encouraged to improve forage for livestock grazing
operations (Blaisdell 1949, p. 519). Large expanses of sagebrush
removed via chemical and mechanical methods have been reseeded with
nonnative grasses, such as crested wheatgrass (Agropyron cristatum), to
increase forage production on public lands (Pechanec et al. 1965 as
cited in Connelly et al. 2004, p.7-28). These treatments reduced or
eliminated many native grasses and forbs present prior to the seedings
(Hull 1974, p. 217). Sage-grouse are affected indirectly through the
loss of native forbs that serve as food and loss of native grasses that
provide concealment or hiding cover (Connelly et al. 2004, p. 4-4).
Water developments for the benefit of livestock and wild ungulates
on public lands are common (Connelly et al. 2004, p. 7-35). Development
of springs and other water sources to support livestock in upland
shrub-steppe habitats can artificially concentrate domestic and wild
ungulates in important sage-grouse habitats, thereby exacerbating
grazing impacts in those areas such as heavy grazing and vegetation
trampling (Braun 1998, p. 147; Knick et al., in press, p. 42).
Diverting the water sources has the secondary effect of changing the
habitat present at the water source before diversion. This impact could
result in the loss of either riparian or wet meadow habitat important
to sage-grouse as sources of forbs or insects. Water developments for
livestock and wild ungulates also could be used as mosquito breeding
habitat, and thus have the potential to facilitate the spread of West
Nile virus (see discussion under Factor C: Disease and Predation).
Another indirect negative impact to sage-grouse from livestock
grazing occurs due to the placement of thousands of miles of fences for
livestock management purposes (see discussion above under
Infrastructure). Fences cause direct mortality through collision and
indirect mortality through the creation of predator perch sites, the
potential creation of predator corridors along fences (particularly if
a road is maintained next to the fence), incursion of exotic species
along the fencing corridor, and habitat fragmentation (Call and Maser
1985, p. 22; Braun 1998, p. 145; Connelly et al. 2000a, p. 974; Beck et
al. 2003, p. 211; Knick et al. 2003, p. 612; Connelly et al. 2004, p.
1-2).
The impacts of livestock operations on sage-grouse depend upon
stocking levels, season of use, and utilization levels. Cattle and
sheep Animal Unit Months (AUMs) (the amount of forage required to feed
one cow with calf, one horse, five sheep, or five goats for 1 month) on
all Federal land have declined since the early 1900s (Laycock et al.
1996, p. 3). By the 1940s, AUMs on all Federal lands (not just areas
occupied by sage-grouse) were estimated to be 14.6 million, increasing
to 16.5 million in the 1950s, and gradually declining to 10.2 million
by the 1990s (Miller and Eddleman 2000, p. 19). Although AUMs have
decreased over time, we cannot assume that the net impact of grazing
has decreased because the productivity of those lands has decreased
(Knick et al., in press, p. 42). As of 2007, the number of permitted
AUMs for BLM lands in States where sage-grouse occur totaled 7,118,989
(Beever and Aldridge, in press, p. 19-20). We estimate that those
permitted AUMs occur in approximately 18,783 BLM grazing allotments in
sage-grouse habitat (Stoner 2008). Since 2005, 644 (3.4 percent) of
those allotments have decreased the permitted AUMs (Service 2008a).
However, BLM tracks the number of AUMs permitted rather than the number
of AUMs actually used. The number permitted typically is higher than
what is used, thus we do not know how the decrease on paper corresponds
to the actual number of AUMs for the last four years.
Wild Horse and Burro Grazing
Free-roaming horses and burros have been a component of sagebrush
and other arid communities since they were brought to North America at
the end of the 16th century (Wagner 1983, p. 116; Beever 2003, p. 887).
About 31,000 wild horses occur in 10 western States (including 2 states
outside the range of the greater sage-grouse), with herd sizes being
largest in Nevada, Wyoming, and Oregon, which are the States with the
most extensive sagebrush cover (Connelly et al. 2004, p. 7-37). Of
about 5,000 burros occur in five western States approximately 700 occur
within the SGCA (Connelly et al. 2004, p.7-37). Beever and Aldridge
(2009, in press, p. 7) estimate that about 12 percent (78, 389 km\2\,
30,266 mi\2\) of sage-grouse habitat is managed for free-roaming horses
and burros. However, the extent to which the equids use land outside of
designated management areas is difficult to quantify but may be
considerable.
We are unaware of any studies that directly address the impact of
wild horses or burros on sagebrush and sage-grouse. However, some
authors have suggested that wild horses could negatively impact
important meadow and spring brood-rearing habitats used by sage-grouse
(Crawford et al. 2004, p. 11; Connelly et al. 2004, p. 7-37). Horses
are generalists, but seasonally their diets can be almost wholly
comprised of grasses (Wagner 1983, pp. 119-120). A comparison of areas
with and without horse grazing showed 1.9 to 2.9 times more grass cover
and higher grass density in areas without horse grazing (Beever et al.
2008 as cited Beever and Aldridge in press, p. 11). Additionally, sites
with horse grazing had less shrub cover and more fragmented shrub
canopies (Beever and Aldridge in press, p. 12). As noted above, sage-
grouse need significant grass and shrub cover for protection from
predators particularly during nesting season, and females will
preferentially choose nesting sites based on these qualities (Hagen et
al. 2007, p. 46). Sites with grazing also generally showed less plant
diversity, altered soil characteristics, and 1.6 to 2.6 times greater
abundance of nonnative Bromus tectorum (Beever et al. 2008 as cited in
Beever and Aldridge 2009, in press, p. 13). These impacts combined
indicate that horse grazing has the potential to result in an overall
decrease in the quality and quantity of sage-grouse habitat in areas
where such grazing occurs.
Currently, free-roaming equids consume an estimated 315,000 to
433,000 AUMs as compared to over 7 million AUMs for domestic livestock
within the range of greater sage-grouse (Beever and Aldridge, in press,
p. 21). Cattle typically outnumber horses by a large degree in areas
where both occur; however, locally ratios of 2:1 (horse:cow) have been
reported (Wagner 1983, p.126). The local effects of ungulate grazing
depend on a host of abiotic and biotic factors (e.g., elevation,
season, soil composition, plant productivity, and composition).
Additional significant biological and behavioral differences influence
the impact of horses as compared to cattle grazing on habitat (Beever
2003, pp. 888-890). For example, due to physiological differences, a
horse must forage longer and consumes 20 to 65 percent more forage than
would a cow of equivalent body mass (Wagner 1983, p. 121; Menard et al.
2002, p.127). Unlike cattle and other ungulates, horses can crop
vegetation close to the ground, potentially limiting or delaying
[[Page 13942]]
recovery of plants (Menard et al. 2002, p.127). In addition, horses
seasonally move to higher elevations, spend less time at water, and
range farther from water sources than cattle (Beever and Aldridge in
press, pp. 20, 21). Given these differences, along with the confounding
factor of past range use, it is difficult to assess the overall
magnitude of the impact of horses on the landscape in general, or on
sage-grouse habitat in particular. In areas grazed by both horses and
cattle, whether the impacts are synergistic or additive is currently
unknown (Beever and Aldridge, in press, p. 21).
Wild Ungulate Herbivory
Native herbivores, such as elk (Cervus elaphus), mule deer, and
pronghorn antelope coexist with sage-grouse in sagebrush ecosystems
(Miller et al. 1994, p. 111). These ungulates are present in sagebrush
ecosystems during various seasons based on dietary needs and forage
availability (Kufeld 1973, p. 106-107; Kufeld et al. 1973 as cited in
Wallmo and Regelin 1981, p. 387-396; Allen et al. 1984, p. 1). Elk
primarily consume grasses but are highly versatile in consumption of
forbs and shrubs when grasses are not available (Kufeld 1973, pp. 106-
107; Vallentine 1990, p. 235). In the winter, heavy snow forces elk to
lower-elevation sagebrush areas where they forage heavily on sagebrush
(Wambolt and Sherwood 1999, p. 225). Mule deer utilize forbs, shrubs,
and grasses throughout the year dependent upon availability and
preference (Kufeld et al. 1973 as cited in Wallmo and Regelin 1981, pp.
389-396). Pronghorn antelope, most commonly associated with grasslands
and sagebrush, consume a wide variety of available shrubs and forbs and
consume new spring grass growth (Allen et al. 1984, p. 1; Vallentine
1990, p. 236).
We are unaware of studies evaluating the effects of native ungulate
herbivory on sage-grouse and sage-grouse habitat. However, concentrated
native ungulate herbivory may impact vegetation in sage-grouse habitat
on a localized scale. Native ungulate winter browsing can have
substantial, localized impacts on sagebrush vigor, resulting in
decreased shrub cover or sagebrush mortality (Wambolt 1996, p. 502;
Wambolt and Hoffman 2004, p. 195). Additionally, despite decreased
habitat availability, elk and mule deer populations are currently
higher than pre-European estimates (Wasley 2004, p. 3; Young and Sparks
1985, pp. 67-68). As a result, some States started small-scale
supplemental feeding programs for deer and elk. In those localized
areas, vegetation is heavily utilized from the concentration of animals
(Doman and Rasmussen 1944, p. 319; Smith 2001, pp. 179-181). Unlike
domestic ungulates, wild ungulates are not confined to the same area,
at the same time each year. Therefore, the impacts from wild ungulates
are spread more diffusely across the landscape, resulting in minimal
long-term impacts to the vegetation community.
Summary: Grazing
Livestock management and domestic grazing can seriously degrade
sage-grouse habitat. Grazing can adversely impact nesting and brood-
rearing habitat by decreasing vegetation concealment from predators.
Grazing also has been shown to compact soils, decrease herbaceous
abundance, increase erosion, and increase the probability of invasion
of exotic plant species. Once plant communities have an invasive annual
grass understory dominance, successful restoration or rehabilitation
techniques are largely unproven and experimental (Pyke, in press, p.
25). Massive systems of fencing constructed to manage domestic
livestock cause direct mortality to sage-grouse in addition to
degrading and fragmenting habitats. Livestock management also can
involve water developments that can degrade important brood-rearing
habitat and or facilitate the spread of WNv. Additionally, some
research suggests there may be direct competition between sage-grouse
and livestock for plant resources. However, although there are obvious
negative impacts, some research suggests that under very specific
conditions grazing can benefit sage-grouse.
Similar to domestic grazing, wild horses and burros have the
potential to negatively affect sage-grouse habitats in areas where they
occur by decreasing grass cover, fragmenting shrub canopies, altering
soil characteristics, decreasing plant diversity, and increasing the
abundance of invasive Bromus tectorum.
Native ungulates have coexisted with sage-grouse in sagebrush
ecosystems. Elk and mule deer browse sagebrush during the winter and
can cause mortality to small patches of sagebrush from heavy winter
use. Pronghorn antelope, largely overlapping with sage-grouse habitat
year around, consume grasses and forbs during the summer and browse on
sagebrush in the winter. We are not aware of research analyzing impacts
from these native ungulates on sage-grouse or sage-grouse habitat.
Currently there is little direct evidence linking grazing practices
to population levels of greater sage-grouse. However, testing for
impacts of grazing at landscape scales important to sage-grouse is
confounded by the fact that almost all sage-grouse habitat has at one
time been grazed and thus no non-grazed, baseline areas currently exist
with which to compare (Knick et al. in press, p. 43). Although we
cannot examine grazing at large spatial scales, we do know that grazing
can have negative impacts to sagebrush and consequently to sage-grouse
at local scales. However, how these impacts operate at large spatial
scales and thus on population levels is currently unknown. Given the
widespread nature of grazing, the potential for population-level
impacts cannot be ignored.
Energy Development
Greater sage-grouse populations are negatively affected by energy
development activities (primarily oil, gas, and coal-bed methane),
especially those that degrade important sagebrush habitat, even when
mitigative measures are implemented (Braun 1998, p. 144; Lyon 2000, pp.
25-28; Holloran 2005, pp. 56-57; Naugle et al. 2006, pp. 8-9; Walker et
al. 2007a, p. 2651; Doherty et al. 2008, p. 192; Harju et al. in press,
p. 22). Impacts can result from direct habitat loss, fragmentation of
important habitats by roads, pipelines, and powerlines (Kaiser 2006, p.
3; Holloran et al. 2007, p. 16), noise (Holloran 2005, p. 56), and
direct human disturbance (Lyon and Anderson 2003, p. 489). The negative
effects of energy development often add to the impacts from other human
development and activities and result in sage-grouse population
declines (Harju et al. in press, p. 22; Naugle et al., in press, p. 1).
For example, 12 years of coal-bed methane gas development in the Powder
River Basin of Wyoming has coincided with 79 percent decline in the
sage-grouse population (Emmerich 2009, pers. comm.). Population
declines associated with energy development result from the abandonment
of leks (Braun et al. 2002, p. 5; Walker et al. 2007a, p. 2649; Clark
et al. 2008, pp. 14, 16), decreased attendance at the leks that persist
(Holloran 2005, pp. 38-39, 50; Kaiser 2006, p. 23; Walker et al. 2007a,
p. 2648; Harju et al. in press, p. 22), lower nest initiation (Lyon
2000, p. 109; Lyon and Anderson 2003, p. 5), poor nest success and
chick survival (Aldridge and Boyce 2007, p. 517), decreased yearling
survival (Holloran et al., in press, p. 6), and avoidance of energy
infrastructure in important wintering habitat (Doherty et al. 2008, pp.
192-193).
[[Page 13943]]
Nonrenewable Energy Sources
Nonrenewable fossil fuel energy development (e.g., petroleum
products, coal) has been occurring in sage-grouse habitats since the
late 1800s (Connelly et al. 2004, p. 7-28). Interest in developing oil
and gas resources in North America has been cyclic based on demand and
market conditions (Braun et al. 2002, p. 2). Between 2004 and 2008, the
exploration and development of fossil fuels in sagebrush habitats
increased rapidly as prices and demand were spurred by geopolitical
uncertainties and legislative mandates (National Petroleum Council
2007, pp. 5-7). Legislative mandates that were used to effect an
increase in energy development include those of the Energy Policy and
Conservation Act (EPCA) of 1975 (42 United States Code (U.S.C.) 6201 et
seq.) to secure energy supplies and increase the availability of fossil
fuels. Reauthorization and amendments to the EPCA have occurred through
subsequent legislation including the Energy Policy Act of 2000 (Public
Law (P.L.) 106-469) that mandates the inventory of Federal nonrenewable
resources (42 U.S.C. 6217). The 2005 Energy Policy Act requires
identification and resolution of impediments to timely granting of
Federal leases and post-leasing development (42 U.S.C. 15851). In
addition, the 2005 Energy Policy Act mandated the designation of
corridors on Federal lands for energy transport (42 U.S.C. 15926),
ordered the identification of renewable energy sources (e.g., wind,
geothermal), and provided incentives for development of renewable
energy sources (42 U.S.C. 15851).
Global recession starting in 2008 resulted in decreased energy
demand and subsequently slowed rate of energy development (Energy
Information Administration (EIA) 2009b, p. 2). However, the production
of fossil fuels is predicted to regain and surpass the early 2008
levels starting in 2010 (EIA 2009b, p. 109). Forecasts to the year 2030
predict fossil fuels to continue to provide for the United States'
energy needs while not necessarily in conventional forms or from
present extraction techniques (EIA 2009b, pp. 2-4, 109). Recent
concerns about curbing greenhouse gas emissions associated with fossil
fuel use are being addressed through government policy, legislation,
and advanced technologies and are likely to effect a transition in fuel
form (EIA 2009b, pp. 2-3, 78).
The decline in use of conventional fossil fuels for power
generation in the future is expected to be supplemented with biomass,
unconventional oil and gas, and renewable sources--all of which are
existing or potentially available in current sage-grouse habitats (U.S.
Department of Energy (DOE) 2006, p. 3; National Petroleum Council 2007,
p. 6; BLM 2005a, p. 2-4; National Renewable Energy Laboratory (NREL)
2008a, entire; Idaho National Engineering and Environmental Laboratory
2003, entire; EIA 2009b, pp. 2-4). For example, oil shale and tar sands
are unconventional fossil fuel liquids predicted for increased
development in the sage-grouse range. Shale sources providing 2 million
barrels per day in 2007 are expected to contribute 5.6-6.1 million
barrels by 2030 (EIA 2009b, p. 30). Extraction of this resource
involves removal of habitat and disturbance similar to oil and gas
development (see discussion below). National reserves of oil shale lie
primarily in the Uinta-Piceance area of Colorado and Utah (MZs II, III,
and VII), and the Green River and Washakie areas of southwestern
Wyoming (MZ II). These 1.4 million ha (3.5 million ac) of Federal lands
contain an estimated 1.23 trillion barrels of oil--more than 50 times
the United States' proven conventional oil reserves (BLM 2008a, p. 2).
Available EPCA inventories detail energy resources in 11 geological
basins (DOI et al. 2008, entire) in the greater sage-grouse
conservation assessment area identified in the 2006 Conservation
Strategy (Stiver et al. 2006, p. 1-11). Extensive oil and gas reserves
are identified in the Williston Basin of western North Dakota,
northwestern South Dakota, and eastern Montana; Montana Thrust Belt in
west-central Montana; Powder River Basin of northeastern Wyoming and
southeastern Montana; Wyoming Thrust Belt of extreme southwestern
Wyoming, northern Utah, and southeastern Idaho; Southwest Wyoming Basin
including portions of southwestern and central Wyoming, northeastern
Utah, and northwestern Colorado; Uinta-Piceance Basin of west-central
Colorado and east-central Utah; Eastern Great Basin in eastern Nevada,
western Utah, and southern Idaho; and Paradox Basin in south-central
and southeastern Utah. Although all these geological basins have some
component of sage habitats, the Southwestern Wyoming Basin as defined
by EPCA (DOI et al. 2008, p. 3-11) is highest in sagebrush-dominated
landscapes (Knick et al. 2003, pp. 613, 615) and is located in MZ II as
described in Stiver et al. 2006 (pp. 1-11).
Oil and gas development has occurred in the past, with historical
well locations concentrated in MZs I, II, III, and VII of Wyoming,
eastern Montana, western Colorado, and eastern Utah (IHS Incorporated
2006). Currently, oil, conventional gas, or coal-bed methane
development occur across the eastern component of the SGCA. Four
geological basins are most affected by a concentration of development--
Powder River (MZ I), Williston (MZ I), Southwestern Wyoming (MZ II),
and the Uinta-Piceance (MZs II, III, VII) coinciding with the highest
proportion of high-density areas of sage-grouse, the greatest number of
leks, and the highest male sage-grouse attendance at leks compared with
any other area in the eastern part of the range (Doherty et al. in
press, p. 11). The Powder River Basin in northeastern Wyoming and
southeastern Montana is home to an important regional population of the
larger Wyoming Basin populations, which represents 25 percent of the
sage-grouse in the species' range (Connelly et al. 2004, p. A4-37). The
Powder River Basin serves as a link to peripheral populations in
eastern Wyoming and western South Dakota and between the Wyoming Basin
and central Montana. The Pinedale Anticline Project is in the Greater
Green River area of the Southwest Wyoming Basin where the subpopulation
in southwestern Wyoming and northwestern Colorado has been a stronghold
for sage-grouse with some of the highest estimated densities of males
per square kilometer anywhere in the remaining range of the species
(Connelly et al. 2004, pp. 6-62, A5-23). The southwestern Wyoming-
northwestern Colorado subpopulation has historically supported more
than 800 leks (Connelly et al. 2004, p. 6-62). The preservation of
large contiguous blocks or interconnected patches of habitats that
exist in southwestern Wyoming is considered a conservation priority for
sage-grouse (Knick and Hanser in press, p. 31).
Extensive development and operations are occurring in sage-grouse
habitats where the number of producing wells has tripled in the past 30
years (Naugle et al., in press, p. 17). More than 8 percent of the
distribution of sagebrush habitats is directly or indirectly affected
by oil and gas development and associated pipelines (Knick et al. in
press, p. 48). Forty-four percent of the 16-million-ha (39-million-ac)
Federal mineral estate in MZs I and II is leased and authorized for
exploration and development (Naugle et al. in press, pp. 17-18).
Wyoming contains the highest percentage of the Federal mineral estate
with 10.6 million ha (26.2 million ac); 52 percent of it is authorized
for development (Naugle et
[[Page 13944]]
al., in press, pp. 17-18). Other Federal mineral estates in the eastern
portion of the sage-grouse conservation assessment area that are
authorized for development include at least 27 percent of Montana's 3.7
million ha (9.1 million ac), 50 percent of 915,000 ha (2.3 million ac)
in Colorado, 25 percent of 405,000 ha (1.0 million ac) in Utah, and 14
percent of North and South Dakota's combined 365,000 ha (902,000 ac)
(Naugle et al. in press, p. 38).
The Great Plains MZ (MZ I) contains all or portions of the 20.9-
million-ha (51.7-million-ac) Powder River and Williston geological
basins identified as significant oil and gas resources. The resource
areas include 7.2 million ha (18.2 million ac) of sagebrush habitats.
Oil and gas infrastructure and planned development occupies less than 1
percent of the land area in MZ I; however, the ecological effect is
greater than 20 percent of the sagebrush habitat, based on applying a
buffer zone to estimate the potential the distance of sage-grouse
response to infrastructure (Lyon and Anderson 2003, p. 489; Knick et
al., in press, p. 133). Energy development is concentrated in the
Powder River geologic basin in northeastern Wyoming and southeastern
Montana. Coal-bed natural gas extraction is the most recent development
in the Powder River Basin, which also is the largest actively producing
coal basin in the United States (Wyoming Mining Association 2008, p.
2).
In 2002, the BLM in Wyoming proposed development of 39,367 coal-bed
methane wells and 3,200 conventional oil or gas wells in the Powder
River Basin in addition to an existing 12,024 coal-bed methane wells
drilled or permitted (BLM 2002, pp. 2-3). Wells would be developed over
a 10-year period with production lasting until 2019 (BLM 2002, p. 3).
The BLM estimated 82,073 ha (202,808 ac) of surface disturbance from
all activities such as well pads, pipelines, roads, compressor
stations, and water handling facilities over a 3.2-million-ha (8-
million-ac) project area (BLM 2002, p. 2). Roads and water handling
facilities were expected to be long-term disturbances encompassing
approximately 38,501 ha (95,140 ac) (BLM 2002, p. 3). Reclamation of
well sites was expected to be complete by 2022 (BLM 2002, p. 3). It is
not clear if this 2022 date takes into consideration the length of time
necessary to achieve suitable habitat conditions for sage-grouse or if
restoration of sage-grouse habitat is possible.
Between 1997 and 2007, approximately 35,000 producing wells were in
place on Federal, State, and private holdings in the Powder River Basin
area (Naugle et al., in press, p. 7). In 2008, the BLM in Montana
completed a supplement to the 2003 Environmental Impact Statement (EIS)
and Record of Decision (ROD) to allow for 5,800-16,500 new coal bed
methane wells in the Montana portion of the Powder River Basin over the
pursuant 20 years (BLM 2008b, pp. 4.2, 4.4-4.5). The BLM estimated a
direct impact of 0.8-1.3 ha (2-3.4 ac) per well site (BLM 2008b, p.
4.11). In addition to the well footprint, each additional group of 2-10
wells has been shown to increase the number of new roads, power lines,
and other infrastructure (Naugle et al. in press, p. 7). Ranching,
tillage agriculture, and energy development are the primary land uses
in the Powder River Basin. The presence of human features and road
densities are high in areas where all three activities coincide to the
level that every 0.8 ha (0.5 mi) could be bounded by a road and
bisected by a power line (Naugle et al. in press, p. 9).
The Powder River Basin serves as a link to peripheral sage-grouse
populations in eastern Wyoming and western South Dakota and between the
Wyoming basin and central Montana. This connectivity is expected to be
lost in the near future because of the intensity of development in the
region. Sage-grouse populations have declined in the Powder River Basin
by 79 percent since the development of coal-bed methane resources
(Emmerich 2009, pers. comm.). In the Powder River Basin between 2001
and 2005, sage-grouse lek-count indices declined by 82 percent inside
gas fields compared to 12 percent outside development (Walker et al.
2007a, p. 2648). By 2004-2005, fewer leks remained active (38 percent)
inside gas fields compared to leks outside fields (84 percent) (Walker
et al. 2007a, p. 2648). Sage-grouse are less likely to use suitable
wintering habitat with abundant sagebrush when coal-bed methane
development is present (Doherty et al. 2008, p. 192). At current
maximum permitted well density (12 wells per 359 ha (888 ac)), planned
full-field development will impact the remaining wintering habitat in
the basin (Doherty et al. 2008, pp. 192, 194) and lead to extirpation.
Energy development in the Powder River Basin is predicted to
continue to actively reduce sage-grouse populations and sagebrush
habitats over the next 20 years based on the length of development and
production projects described in existing project and management plans.
The BLM concluded that sage-grouse habitats would not be restored to
pre-disturbance conditions for an extended time (BLM 2003, p. 4-268).
Sagebrush restoration after development is difficult to achieve, and
successful restoration is not assured as described above (Habitat
Description and Characteristics).
The 9.6-million-ha (23.9-million-ac) Williston Basin underlies the
northeastern corner of the current sage-grouse range in Montana, North
and South Dakota. It is another energy resource area experiencing
concentrated oil and gas development in MZ I. Oil production has
occurred in the Williston Basin for at least 80 years with oil
production peaking in the 1980s (Advanced Resources International 2006,
p. 3-3). Advances in technology including directional drilling and
coal-bed methane technology have boosted development of oil and gas in
the basin (Advanced Resources International 2006, p. 3.2; Zander 2008,
p. 1). Large, developed fields are concentrated in the Bowdoin Dome
area of north-central Montana and the 193-km (120-mi) long Cedar Creek
Anticline area of southeastern Montana, southwestern North Dakota, and
northwestern South Dakota. Extensive energy development in the Cedar
Creek Anticline area could be isolating the very small North Dakota
population from sage-grouse populations in central Montana and the
northern Powder River Basin.
One hundred and thirty-six wells were put into production in 2008-
2009 in major oil and gas fields of the Williston Basin north of the
Missouri River in the range of the Northern Montana sage-grouse
population (Montana Department of Natural Resources 2009, entire)
including the Bowdoin Dome area. The Bowdoin Dome area is populated by
more than 1,500 gas wells with associated infrastructure, and an
additional 1,200 new or replacement wells were approved in the
remaining occupied active sage-grouse habitat (BLM 2008c, pp. 1, 3-127
to 3-129). Active drilling operations are expected to occur over 10-15
years, and gas production is expected to extend the project life 30-50
additional years (BLM 2008c, p. 1). The BLM's project description does
not take into consideration the time period necessary to restore native
sagebrush communities to suitability for sage-grouse. Energy
extraction, ranching, and tillage agriculture coincide in this area of
the State described by Leu and Hanser (in press, p. 44) as experiencing
high-intensity human activity that is consistent with lek loss and
population decline (Wisdom et al., in press, p. 23). Energy development
in Montana has contributed to post-settlement sage-
[[Page 13945]]
grouse range contraction and possibly the geographic separation of the
existing subpopulations in northern Montana and Canada. Foreseeable
development is expected to further reduce the remaining sage-grouse
habitat within developed oil and gas fields, and contribute to future
range and population reductions (Copeland et al. 2009, p. 5).
Southwestern and central Wyoming and northwestern Colorado in MZ II
has been considered a stronghold for sage-grouse with some of the
highest estimated densities of males anywhere in the remaining range of
the species (Connelly et al. 2004, pp. 6-62, A5-23). Wisdom et al. (in
press, p. 23) identified this high-density sagebrush area as one of the
highest priorities for conservation consideration as it comprises one
of two remaining areas of contiguous range essential for the long-term
persistence of the species. The Southwestern Wyoming geological basin
also is experiencing significant growth in energy development which,
based on the conclusions of recent investigations on the effects of oil
and gas development, is expected over time to reduce sage-grouse
habitat, increase fragmentation, and decrease and isolate sage-grouse
populations leading to extirpations.
Oil, gas, and coal-bed methane development is occurring across MZ
II, and development is concentrated in some areas. Intensive
development and production is occurring in the Greater Green River area
in southwestern Wyoming and northern Colorado and northeastern Utah.
The BLM published a ROD in 2000 for the Pinedale Anticline Project Area
in southwestern Wyoming (BLM 2000, entire). The project description
included up to 900 drill pads, including dry holes, over a 10- to 15-
year development period (BLM 2008d, p. 4-4). By the end of 2005,
approximately 457 wells on 322 well pads were under production (BLM
2008d, p. 6). In 2008, the BLM amended the project to accommodate an
accelerated rate of development exceeding that in the 2002 project
description (BLM 2008d, p. 4). Approximately 250 new well pads are
proposed in addition to pipelines and other facilities (BLM 2008d, p.
36). Total initial direct disturbance acres for the entire Pinedale
project are approximately 10,400 ha (25,800 ac) with more than 7,200 ha
(18,000 ac) in sagebrush land cover type (BLM 2008d, p. 4-52).
The Jonah Gas Infill Project also is underway in the Pinedale
Anticline area of the Southwest Wyoming Basin that expands on the Jonah
Project started in 2000. In 2006, the BLM issued a ROD and EIS to
extend the existing project to an additional 3,100 wells and up to
6,556 ha (16,200 ac) of new surface disturbance (BLM 2006, p. 2-4). In
addition, at least 64 well pads would be situated per 259 ha (640 ac),
and up to 761 km (473 mi) of pipeline and roads, 56 ha (140 ac) of
additional disturbance for ancillary facilities (p. 2-5) also would
occur. The project life of 76 years includes 13 years of development
and 63 years of production (BLM 2006, p. 2-15). The project description
requires reclamation of disturbed sites and establishment of
stabilizing vegetation by 1 year post-reclamation (BLM 2006, p. 2-24)
and standard lease stipulations to protect sage-grouse. This project is
located in high-density sage-grouse habitat, but it is not clear from
the project description if suitable sage-grouse habitat is the
reclamation goal. Therefore, sagebrush habitats, and the associated
sage-grouse are likely to be lost.
Knick et al. (in press, pp. 49, 128) reviewed BLM documents for the
Greater Green River Basin area, which includes the Pinedale and Jonah
projects, and reported that 6,185 wells have been drilled, and there
are agency plans for more than 9,300 wells and associated
infrastructure. Existing and planned energy development influences over
20 percent of the sagebrush area in the Wyoming Basin (MZ II) (Knick et
al., in press, p. 133). Drilling, gas production, and traffic on main
haul roads have all been shown to affect lek attendance and lek
persistence when it coincides with breeding habitat within 3.2 km (2
mi) (Holloran 2005, p. 40; Walker et al. 2007a, p. 2651). Using 2006
well point data and, therefore, a conservative estimate as oil
exploration and development experienced significant growth between 2006
and 2008, we calculated that 21 to 35 percent of active breeding
habitat for subpopulations in the Southwest Wyoming geological basin
may be negatively impacted by the proximity of energy development
(Service 2008b).
In the Greater Green River Basin area, yearling male sage-grouse
reared near gas field infrastructure had lower survival rates and were
less likely to establish breeding territories than males with less
exposure to energy development; yearling female sage-grouse avoided
nesting within 950 m (0.6 mi) of natural gas infrastructure (Holloran
et al., in press, p. 6). The fidelity of sage-grouse to natal sites may
result in birds staying in areas with development but they do not breed
(Lyon and Anderson 2003, p. 49; Walker et al. 2007a, p. 2651; Holloran
et al., in press, p. 6). The effect of energy development on sage-
grouse population numbers may then take 4 to 5 years to appear (Walker
et al. 2007a, p. 2651). Copeland et al. (2009, p. 5) depicted an
extensive development scenario for southwest Wyoming, northern
Colorado, and northeastern Utah based on known reserves and existing
project plans that indicates an intersection between future oil and gas
development and high-density sage-grouse core areas that could result
in 6.3 to 24.1 percent decrease in sage-grouse numbers over the next 20
years in MZ II (Copeland 2010, pers. comm.).
The Greater Green River area of southwest Wyoming and the Uintah-
Piceance basin (discussed below) also are, in addition to oil and gas,
important reserves of oil shale and tar sands that are expected to
supply more of the nation's resource needs in the future (EIA 2009b, p.
30). The Uintah-Piceance geologic basin includes the Colorado Plateau
(MZ VII) and overlaps into the southern edge of the Wyoming Basin (MZ
II). Sage-grouse in this part of the range are reduced to four small,
isolated populations, a likely consequence of urban and agricultural
development (Knick et al., in press, pp. 106-107; Leu and Hanser, in
press, p. 15). All four populations are threatened by environmental,
demographic, and genetic stochasticity due to their small population
sizes as well as housing and energy development, predation, disease,
and conifer invasion (Garton et al., in press, p. 7; Petch 2009, pers.
comm.; Maxfield 2009, pers. comm.) although population data are limited
for most of this area (Garton et al., in press, p. 63).
Based on applying a 3 km (1.9 mi) buffer to construction areas,
Knick et al. (in press, p. 133) estimate existing energy development
affects over 30 percent of sagebrush habitats in this area. In the past
4 years, the number of oil and gas wells increased in sage-grouse
habitats of northwestern Colorado and northeastern Utah by 325 and 870
wells, respectively (Service 2008c). More than 1,370 wells were
completed in Uintah (location of the two Utah populations) and Duchesne
Counties of northeast Utah between July 2008 and August 2009 (Utah Oil
and Gas Program 2009, entire), and approximately 7,700 wells are active
in the counties (Utah DNRC 2009, entire). We expect that the
development of energy resources will continue based on available
reserves and recent development history (Copeland et al. 2009, p. 5),
and development will further stress the persistence of these small
populations at the southern edge of the sage-grouse range.
[[Page 13946]]
Using GIS analysis, we calculated that 70 percent of the sage-
grouse breeding habitat is potentially impacted by oil and gas
development in the Powder River Basin (Service 2008b). The 70 percent
figure was derived from well point data supplied by the BLM, buffered
by 3.2 km (2 mi), and intersecting these areas with known lek locations
buffered to 6.4 km (4 mi). The 70 percent figure is conservative
because the most comprehensive well point data set available was 2
years old and did not reflect the rapid development that occurred in
2008. Breeding habitat is defined as a 6.4-km (4-mi) radius around
known lek points and includes the range of the average distances
between nests and nearest lek (Autenrieth 1981, p. 18; Wakkinen et al.
1992, p. 2).
The effects of oil and gas development, as described in detail
later in this section, are likely to continue for decades even with the
current protective or mitigative measures in place. Based on a review
of project EISs, Connelly et al. (2004, p. 7-41) concluded that the
economic life of a coal-bed methane well averages 12-18 years and 20-
100 years for deep oil and gas wells. A recent review of energy
projects in development, primarily gas and coal-bed methane, supports
these timeframes (BLM 2008b, p. 4-2; 2008c, p. 2; 2009b, p. 2). In
addition, many energy projects are tiered to the 20-year land use plans
developed by individual BLM field offices or districts to guide
development and other activities.
The BLM is the primary Federal agency managing the United States'
energy resources and has the legal authority to regulate and condition
oil and gas leases and permits. Although the restrictive stipulations
that BLM applies to permits and leases are variable, a 0.4-km (0.25-mi)
radius around sage-grouse leks is generally restricted to no surface
occupancy (NSO) during the breeding season, and noise and development
activities are often limited during the breeding season within a 0.8-
to 3.2-km (0.5 to 2-mi) radius of sage-grouse leks. As stated above,
the BLM's NSO buffer stipulation is ineffective in protecting sage-
grouse (Walker et al. 2007a, p. 2651), and it is not applied or
applicable to all development sites (see discussion under Factor D). We
estimated the sage-grouse breeding habitat impacted within 0.4 km (0.25
mi) of a producing well or drilling site with an approved BLM permit
using 2006 well-site locations (the most comprehensive data available
to us). Figures derived from the 2006 data are conservative because the
rapid pace of development in 2007 and 2008 is not reflected. Within
16.2 million ha (38 million ac) of sage-grouse breeding habitat in MZs
I and II (where 65 percent of all sage-grouse reside), approximately
1.7 million ha (4.2 million ac) or 10 percent are within 0.4 km (0.25
mi) of a producing well, drilling operation or site (Service 2008d).
Walker et al. (2007a, p. 2651) reported negative impacts on lek
attendance of coal-bed methane development within 0.8 km (0.5 mi) and
3.2 km (2 mi) of a lek, and Holloran (2005, pp. 57-60) observed that
the influence of producing well sites and mail haul roads on lek
attendance extended to at least 3 km (2 mi). Expanding our analysis
area from 0.4 km (0.25 mi) to include breeding habitat within 3 km (2
mi) of producing well or drilling sites with an approved BLM permit, we
determined that 40 percent of the sage-grouse breeding habitat in MZs I
and II is potentially affected by oil or gas development (Service
2008b).
In some cases, localized areas are experiencing higher levels of
effects. Seventy percent of the sage-grouse breeding habitat is within
3 km (2 mi) of development in the Powder River Basin of northeastern
Wyoming and southeastern Montana (Service 2008b), where Walker et al.
(2007, p. 2651) concluded that full-field development would reduce the
probability of lek persistence from 87 to 5 percent. Our analyses show
that subpopulations of sage-grouse in MZ II have up to 35 percent of
breeding habitat within 3.2 km (2 mi) of development, and where data
are available for populations in the Uintah-Piceance Basin of Colorado
and Utah, 100 percent of the breeding habitat is affected by oil and
gas development (Service 2008b). Additionally these calculations do not
take into account the added effects of loss of habitat or habitat
effectiveness resulting from the increasing level of renewable energy
development or other anthropogenic factors occurring in concert with
oil and gas development, such as agricultural tillage, urban expansion,
or predation, fire, and invasives (see discussions under those
headings).
Energy development impacts sage-grouse and sagebrush habitats
through direct habitat loss from well pad, access construction, seismic
surveys, roads, powerlines, and pipeline corridors; indirectly from
noise, gaseous emissions, changes in water availability and quality,
and human presence; and the interaction and intensity of effects could
cumulatively or individually lead to fragmentation (Suter 1978, pp. 6-
13; Aldridge 1998, p. 12; Braun 1998, pp. 144-148; Aldridge and Brigham
2003, p. 31; Knick et al. 2003, pp. 612, 619; Lyon and Anderson 2003,
pp. 489-490; Connelly et al. 2004, pp. 7-40 to 7-41; Holloran 2005, pp.
56-57; Holloran 2007, pp. 18-19; Aldridge and Boyce 2007, pp. 521-522;
Walker et al. 2007a, pp. 2652-2653; Zou et al. 2006, pp. 1039-1040;
Doherty et al. 2008, p. 193; Leu and Hanser, in press, p. 28).
The development of oil and gas resources requires surveys for
economically recoverable reserves, construction of well pads and access
roads, subsequent drilling and extraction, and transport of oil and
gas, typically through pipelines. Ancillary facilities can include
compressor stations, pumping stations, electrical generators, and
powerlines (Connelly et al. 2004, p. 7-39; BLM 2007c, p. 2-110).
Surveys for recoverable resources occur primarily through seismic
activities, using vibroesis buggies (thumpers) or shothole explosives.
Well pads vary in size from 0.10 ha (0.25 ac) for coal-bed natural gas
wells in areas of level topography to greater than 7 ha (17.3 ac) for
deep gas wells and multiwell pads (Connelly et al. 2004, p. 7-39; BLM
2007c, p. 2-123). Pads for compressor stations require 5-7 ha (12.4-
17.3 ac) (Connelly et al. 2004, p. 7-39).
Well densities and spacing are typically designed to maximize
recovery of the resource and are administered by State oil and gas
agencies and the BLM, the Federal agency charged with administering the
nation's Federal mineral estate (Connelly et al. 2004 pp. 7-39 to 7-
40). Well density on BLM-administered lands is incorporated in land use
plans and often based on the spacing decision of individual State oil
and gas boards. Each geologic basin has a standard spacing, but
exemptions are granted. Density of wells for current major developments
in the sage-grouse range vary from 1 well per 2 ha (5ac) to 1 well per
64 ha (158 ac) (Knick et al., in press, pp. 128). Greater sage-grouse
respond to the density and distribution of infrastructure on the
landscape. Holloran (2005, pp. 38-39, 50) reported that male sage-
grouse attendance at leks decreased over 23 percent in gas fields where
well density was 5 or more within 3 km (1.9 mi). Sage-grouse are less
likely to occupy areas with wells at a 32 ha (80 ac) spacing than a 400
ha (988 ac) spacing (Doherty et al. 2008, p. 193).
Direct habitat loss from the human footprint contributes to
decreased population numbers and distribution of the greater sage-
grouse (Knick et al. 2003, p. 1; Connelly et al. 2004, p. 7-40;
Aldridge et al. 2008, p. 983; Copeland et al. 2009, p. 6; Knick et al.,
in press, p. 60; Leu and Hanser, in press, p. 5).
[[Page 13947]]
The footprint of energy development contributes to direct habitat loss
from construction of well pads, roads, pipelines, powerlines, and
through the crushing of vegetation during seismic surveys. The amount
of direct habitat loss within an area is ultimately determined by well
densities and the associated loss from ancillary facilities.
The ecological footprint is the extended effect of the
infrastructure or activity beyond its physical footprint and determined
by a physical or behavioral response of the sage-grouse. The physical
footprint of oil and gas infrastructure including pipelines is
estimated to be 5 million ha (1.2 million ac) and less than 1 percent
of the SGCA (Knick et al., in press, p. 133). However, the estimated
ecological footprint is more than 13.8 million ha (34.2 million ac) or
6.7 percent of the SGCA (Knick et al., in press, p. 133) based on
applying a buffer zone to estimate potential avoidance, increased
mortality risk, and lowered fecundity in the vicinity of development
(Lyon and Anderson 2003, p. 459; Walker et al. 2007a, p. 2651; Holloran
et al. in press, p. 6). Based on their method, Knick et al. (in press,
p. 133) estimated more than 8 percent of sagebrush habitats within the
SGCA are affected by energy development. The MZs with concentrations of
oil and gas development have a higher estimated percentage of sagebrush
habitats affected: 20 percent of the Great Plains (MZ I), 20 percent of
the Wyoming Basin (MZ II), and 29 percent of the Colorado Plateau (MZ
VII) (Knick et al, in press, p. 133). Copeland et al. (2009, p. 6)
predict a scenario with a minimum of 2.3 million additional ha (5.7
million ac) directly impacted by oil and gas development by the year
2030. The corresponding ecological footprint is likely much larger. The
projected increase in oil and gas energy development within the sage-
grouse range could reduce the population by 7 to 19 percent from
today's numbers (Copeland et al. 2009, p. 6). This projection does not
reflect the effects of the increased development of renewable energy
sources.
Roads associated with oil and gas development were suggested to be
the primary impact to greater sage-grouse due to their persistence and
continued use even after drilling and production ceased (Lyon and
Anderson 2003, p. 489). Declines in male lek attendance were reported
within 3 km (1.9 mi) of a well or haul road with a traffic volume
exceeding one vehicle per day (Holloran 2005, p. 40; Walker et al.
2008a, p. 2651). Sage-grouse also may be at increased risk for
collision with vehicles simply due to the increased traffic associated
with oil and gas activities (Aldridge 1998, p. 14; BLM 2003, p. 4-222).
Habitat fragmentation resulting from oil and gas development
infrastructure, including access roads, may have effects on sage-grouse
greater than the associated direct habitat losses. The Powder River
Basin infrastructure footprint is relatively small (typically 6-8 ha
per 2.6 km\2\ (15-20 ac per section)). Considering the mostly
contiguous nature of the project area, the density of facilities could
affect sage-grouse habitats on over 2.4 million ha (5.9 million ac).
Energy development and associated infrastructure works cumulatively
with other human activity or development to decrease available habitat
and increase fragmentation. Walker et al. (2007, p. 2652) determined
that leks had the lowest probability of persisting (40-50 percent) in a
landscape with less than 30 percent sagebrush within 6.4 km (4 mi) of
the lek. These probabilities were even less in landscapes where energy
development also was a factor.
Noise can drive away wildlife, cause physiological stress, and
interfere with auditory cues and intraspecific communication. Aldridge
and Brigham (2003, p. 32) reported that, in the absence of stipulations
to minimize the effects of noise, mechanical activities at well sites
may disrupt sage-grouse breeding and nesting activities. Hens bred on
leks within 3 km (1.9 mi) of oil and gas development in the upper Green
River Basin of Wyoming selected nest sites with higher total shrub
canopy cover and average live sagebrush height than hens nesting away
from disturbance (Lyon 2000, p. 109). The author hypothesized that
exposure to road noise associated with oil and gas drilling may have
been one cause for the difference in habitat selection. However, noise
could not be separated from the potential effects of increased
predation resulting from the presence of a new road. In the Pinedale
Anticline area of southwest Wyoming, lek attendance declined most
noticeably downwind from a drilling rig indicating that noise likely
affected male presence (Holloran 2005, p. 49).
Above-ground noise is typically not regulated to mitigate effects
to sage-grouse or other wildlife (Connelly et al. 2004, p. 7-40).
Ground shock from seismic activities may affect sage-grouse if it
occurs during the lekking or nesting seasons (Moore and Mills 1977, p.
137). We are unaware of any research on the impact of ground shock to
sage-grouse.
Water quality and quantity may be affected by oil and gas
development. In many large field developments, the contamination threat
is minimized by storing water produced by the gas dehydration process
in tanks. Water also may be depleted from natural sources for drilling
or dust suppression purposes. Concentrating wildlife and domestic
livestock may increase habitat degradation at remaining water sources.
Negative effects of changes in water quality, availability, and
distribution are a reduction in habitat quality (e.g., trampling of
vegetation, changes in water filtration rates), and habitat degradation
(e.g., poor vegetation growth), which could result in brood habitat
loss. However, we have no data to suggest that this, by itself, is a
limiting factor to sage-grouse.
Water produced by coal-bed methane drilling may benefit sage-grouse
through expansion of existing riparian areas and creation of new areas
(BLM 2003, p. 4-223). These habitats could provide additional brood
rearing and summering habitats for sage-grouse. However, the increased
surface-water on the landscape may negatively impact sage-grouse
populations by providing an environment for disease vectors (Walker and
Naugle in press, p. 13). Based on the 2002 discovery of WNv in the
Powder River Basin, and the resulting mortalities of sage-grouse
(Naugle et al. 2004, p. 705), there is concern that produced water
could have a negative impact if it creates suitable breeding reservoirs
for the mosquito vector of this disease (see also discussion in Factor
C, Disease and Predation). Produced water also could result in direct
habitat loss through prolonged flooding of sagebrush areas, or if the
discharged water is of poor quality because of high salt or other
mineral content, either of which could result in the loss of sagebrush
or grasses and forbs necessary for foraging broods (BLM 2003, p. 4-
223).
Air quality could be affected where combustion engine emissions,
fugitive dust from road use and wind erosion, natural gas-flaring,
fugitive emissions from production site equipment, and other activities
(BLM 2008d, p. 4-74) occur in sage-grouse habitats. Presumably, as with
surface mining, these emissions are quickly dispersed in the windy,
open conditions of sagebrush habitats (Moore and Mills 1977, p. 109),
minimizing the potential effects on sage-grouse. However, high-density
development could produce airborne pollutants that reach or exceed
quality standards in localized areas for short periods of time (BLM
2008d, pp. 4-82 to 4-88). Walker (2008, entire) characterized emissions
from well flaring in the Pinedale Anticline area of Sublette County,
Wyoming. The
[[Page 13948]]
investigator suggested a comprehensive study be conducted by regulatory
agencies of the potential health effects of alkali elements in
combusted well-plume material (Walker 2008, entire). No information is
available regarding the effects to sage-grouse of gaseous emissions
produced by oil and gas development.
Increased human presence resulting from oil and gas development can
impact sage-grouse either through avoidance of suitable habitat,
disruption of breeding activities, or increased hunting and poaching
pressure (Braun et al. 2002, pp. 4-5; Aldridge and Brigham 2003, pp.
30-31; Aldridge and Boyce 2007, p. 518; Doherty et al. 2008, p. 194).
Sage-grouse also may be at increased risk for collision with vehicles
simply due to the increased traffic associated with oil and gas
activities (BLM 2003, p. 4-216).
Negative effects of direct habitat disturbance can be offset by
successful reclamation. Reclamation of areas disturbed by oil and gas
development can be concurrent with field development or conducted after
the shut-in or abandonment of the well or field. Sage-grouse may
repopulate the area as disturbed areas are reclaimed. However, there is
no evidence that populations will attain their previous size, and
reestablishment may take 20 to 30 years (Braun 1998, p. 144). For most
developments, return to pre-disturbance population levels is not
expected due to a net loss and fragmentation of habitat (Braun et al.
2002, p. 150). After 20 years, sage-grouse have not recovered to pre-
development numbers in Alberta, even though well pads in these areas
have been reclaimed (Braun et al. 2002, pp. 4-5). In some reclaimed
areas, sage-grouse have not returned (Aldridge and Brigham 2003, p.
31).
Mining
Mining began in the range of the sage-grouse before 1900 (State of
Wyoming, 1898; U.S. Census 1913, p. 187) and continues today.
Currently, surface and subsurface mining activities for numerous
resources are conducted in all 11 States across the sage-grouse range.
We do not have comprehensive information on the number or surface
extent of mines across the range, but the development of mineral
resources is occurring in sage-grouse habitats and is important to the
economies of a few of the States. Nevada (MZs III, IV, and V) is ranked
second in the United States in terms of value of overall nonfuel
mineral production in 2006 (USGS 2006, p. 10). Wyoming (MZs I and II)
is the largest coal producer in the United States, and the top ten
producing mines in the country are located in Wyoming's Powder River
Basin (MZ I) (Wyoming Mining Association 2008, p. 2). A preliminary
estimate of at least 9.9 km\2\ (3.8 mi\2\) of occupied sage-grouse
habitat will be directly impacted by new or expanded mining operations,
currently in the planning phase, for coal in Montana (MZ I) and Utah
(MZ III), for phosphate in Idaho (MZ IV), and uranium in Nevada (MZ IV)
and Wyoming (MZs I and II) (Service 2008b).
Uranium mining and milling has occurred in Wyoming, Utah, and
Colorado, and Nevada within the greater sage-grouse conservation area;
however, recent production has been very limited with only one
operation in production in Wyoming (EIA 2009c, entire). Tax credits
indicated in the 2005 Energy Policy Act and concerns for green-house
gas emissions associated with fossil-fuel electricity generation are
expected to increase nuclear power generation (EIA 2009b, p. 73) and
stimulate the demand for uranium. Electricity supplied by nuclear
plants is expected to increase 2-55 percent by 2030; the increase is
dependent on variables such as construction costs and regulatory
mandates (EIA 2009b, p. 52), which are difficult to predict. In 2009,
industry announced the intent to pursue development (Peninsula Minerals
2009, entire), and the Nuclear Regulatory Commission announced the
review of numerous new uranium facilities in Wyoming (74 FR 41174,
Uaugust 14, 2009; 74 FR 45656, September 3, 2009). Areas in central
Wyoming and Wyoming's Powder River Basin are considered major reserves
of uranium coinciding with areas of high sage-grouse population
densities (Finch 1996, pp. 19-20; Wyoming State Governor's Sage-grouse
Implementation Team 2008, entire).
Bentonite mining has been conducted on over 85 km\2\ (33 mi\2\) in
the Bighorn Basin of north-central Wyoming (EDAW, Inc. and BLM 2008, p.
1). Bentonite is a primary component of oil and gas drilling muds. The
loss of sagebrush associated with bentonite mining has been intensive
on a localized level and has contributed to altering 12 percent of the
sagebrush habitats in the 2,173 km\2\ (839 mi\2\) Bighorn Basin (EDAW
Inc., and BLM 2008, p. 2). Restoration efforts at mine sites have been
mostly unsuccessful (EDAW, Inc. and BLM 2008, p. 1). The BLM foresees
up to 89 additional km\2\ (34 mi\2\) to be disturbed by bentonite
mining in the area through 2024, in addition to possible oil and gas
and energy transmission disturbances (EDAW, Inc. and BLM 2008, p. 2;
BLM 2009c, p. 5).
Between 2006 and 2007, surface coal production decreased 9 percent
in Colorado while increasing by 1.6 and 4.4 percent in Wyoming (MZ I)
and Montana (MZ I), respectively (EIA 2008a, entire). The number of
Wyoming coal mines increased from 19 in 2005 to 23 in 2008 (Wyoming
Mining Association 2005, p. 5). All of Wyoming's 23 coal mines are in
sagebrush and in the SGCA. Sixteen of these mines are located in the
Powder River Basin (MZ I) where oil and gas development is extensive
(Wyoming Mining Association 2008, p. 2).
Coal mining in Montana is focused in the Powder River Basin just
north of the Wyoming border, in sagebrush habitat. In Wyoming and
Montana, an estimated 558 km\2\ (215 mi\2\) of sagebrush habitats have
been disturbed by coal mines and associated facilities; disturbance
increased approximately 170 km\2\ (66 mi\2\) between 2005 and 2007
(Service 2005, p. 75; Service 2008c; Wyoming Mining Association 2008,
p. 7). Wyoming estimates that 275 km\2\ ha (106 mi\2\) of mine-
disturbed land has been reclaimed (Wyoming Mining Association 2008, p.
7), but we have no knowledge of the effectiveness of these reclamation
projects in providing functional sage-grouse habitat.
While western coal production has grown steadily since 1970, growth
is predicted to increase through 2030, but at a much slower rate than
in the past (EIA 2009b, p. 83). Coal production is projected to
increase with the development of technology to reduce sulfur emissions
and most of the future output of coal is expected from low-sulfur coal
mines in Wyoming, Montana, and North Dakota (EIA 2009b, p. 83). We do
not have information to quantify the footprint of future coal
production; however, additional losses and deterioration of sage-grouse
habitats are expected where mining activity occurs (described later in
this section). The use of coal may be reduced if limitations on green-
house gas emissions are enacted in the future. A transition would
require development of lower emission sources, such as wind, solar, or
nuclear, that may have their own impacts on sage-grouse environments.
Surface and subsurface mining for mineral resources (coal, uranium,
copper, phosphate, aggregate, and others) results in direct loss of
habitat if occurring in sagebrush habitats. The direct impact from
surface mining is usually greater than it is from subsurface activity.
Habitat loss from both types of mining can be exacerbated by the
storage of overburden (soil removed to reach subsurface resource)
[[Page 13949]]
in otherwise undisturbed habitat. If the construction of mining
infrastructure is necessary, additional direct loss of habitat could
result from structures, staging areas, roads, railroad tracks, and
powerlines. Sage-grouse and nests could be directly affected by
trampling or vehicle collision. Sage-grouse also will likely be
impacted indirectly from an increase in human presence, land use
practices, ground shock, noise, dust, reduced air quality, degradation
of water quality and quantity, and changes in vegetation and topography
(Moore and Mills 1977, entire; Brown and Clayton 2004, p. 2).
An increase in human presence increases collision risk with
vehicles and potentially exposes sage-grouse and other wildlife to
pathogens introduced from septic systems and waste disposal (Moore and
Mills 1977, pp. 114-116, 135). Water contamination also could occur
from leaching of waste rock and overburden and nutrients from blasting
chemicals and fertilizer (Moore and Mills 1977, pp. 115, 133). Altering
of water regimes could lead to decreased surface water and eventual
habitat degradation from wildlife or livestock concentrating at
remaining sources. Sage-grouse do not require water other than what
they obtain from plant resources (Schroeder et al. 1999, p. 6);
therefore, local water quality deterioration or dewatering is not
expected to have population-level impacts. Degradation of riparian
areas could result in a loss of brood habitat.
Mining and associated activities creates an opportunity for
invasion of exotic and noxious weed species that alter suitability for
sage-grouse (Moore and Mills 1977, pp. 125, 129). Reclamation is
required by State and Federal laws, but laws generally allow for a
change in post-mining land use. Restoration of sagebrush is difficult
to achieve and disturbed sites may never return to suitability for
sage-grouse (refer to Habitat Description and Characteristics section).
Heavy equipment operations and use of unpaved roads produces dust
that can interfere with plant photosynthesis and insect populations.
Most large surface mines are required to control dust. Gaseous
emissions generated from heavy equipment operation are quickly
dispersed in open, windy areas typical of sagebrush (Moore and Mills
1977, p.109). Blasting, to remove overburden or the target mineral,
produces noise and ground shock. The full effect of ground shock on
wildlife is unknown. Repeated use of explosives during lekking activity
could potentially result in lek or nest abandonment (Moore and Mills
1977, p. 137). Noise from mining activity could mask vocalizations
resulting in reduced female attendance and yearling recruitment as seen
in sharp-tailed grouse (Pedioecetes phasianellus) (Amstrup and Phillips
1977, pp. 23, 25-27). In this study, the authors found that the mining
noise in the study area was continuous across days and seasons and did
not diminish as it traveled from its source. The mechanism of how noise
affects sage-grouse is not known, but it is known that sage-grouse
depend on acoustical signals to attract females to leks (Gibson and
Bradbury 1985, pp. 81-82; Gratson 1993, pp. 693-694). Noise associated
with oil and gas development may have played a factor in habitat
selection and a decrease in lek attendance by sage-grouse (Holloran
2005, pp. 49, 56).
A few scientific studies specifically examine the effects of coal
mining on greater sage-grouse. In a study in North Park, Colorado,
overall sage-grouse population numbers were not reduced, but there was
a reduction in the number of males attending leks within 2 km (0.8 mi)
of three coal mines, and existing leks failed to recruit yearling males
(Braun 1986, pp. 229-230; Remington and Braun 1991, pp. 131-132). New
leks formed farther from mining disturbance (Remington and Braun 1991,
p. 131). Additionally, some leks that were abandoned adjacent to mine
areas were reestablished when mining activities ceased, suggesting
disturbance rather than habitat loss was the limiting factor (Remington
and Braun 1991, p.132). Hen survival did not decline in a population of
sage-grouse near large surface coal mines in northeast Wyoming, and
nest success appeared not to be affected by adjacent mining activity
(Brown and Clayton 2004, p. 1). However, the authors concluded that
continued mining would result in fragmentation and eventually impact
sage-grouse persistence if adequate reclamation was not employed (Brown
and Clayton 2004, p.16).
Surface coal mining and associated activities have negative short-
term impacts on sage-grouse numbers and habitats near mines (Braun
1998, p. 143). Sage-grouse will reestablish on mined areas once mining
has ceased, but there is no evidence that population levels will reach
their previous size, and any population reestablishment could take 20
to 30 years based on observations of disturbance in oil and gas fields
(Braun 1998, p. 144). Local sage-grouse populations could decline if
several leks are affected by coal mining, but the loss of one or two
leks in a regional area was likely not limiting to local populations in
the Caballo Rojo Mine in northeastern Wyoming based on the presence of
viable habitat elsewhere in the region (Hayden-Wing Associates 1983, p.
81).
As described above, mining directly removes habitat, may interfere
with auditory clues important to mate selection, and results in a
decrease of males and inhibits yearling recruitment at leks in
proximity to mining activity. Sage-grouse habitat reestablishment and
recovery of population numbers in an area post-disturbance is
uncertain. Similar avoidance of disturbance has been noted in recent
investigations of oil and gas development in Wyoming and discussed in
detail in the Nonrenewable Energy section. The studies recounted here
were conducted on a local scale that provides limited insight into
impacts at a larger landscape perspective. In Wyoming specifically, the
cumulative impacts of surface coal mine disturbance, concurrent
increases in oil and gas development, increased development of
renewable energy resources (discussed in the following section), and
transmission infrastructure development could have significant impacts
on sage-grouse in the Powder River Basin. The Powder River Basin is
home to an important regional population of the larger Wyoming Basin
populations covering most of Wyoming, northwestern Colorado, and
northeastern Utah (Connelly et al. 2004, pp. 6-62 to 6-63).
Renewable Energy Sources
The demand for electricity from renewable energy sources is
increasing. Electricity production from renewable sources increased
from 6.4 quadrillion British thermal units (Btu) in 2005 to 6.9
quadrillion Btu in 2006. Production was down slightly in 2007, but
energy production by renewables reached 7.3 quadrillion Btu by the end
of 2008 (EIA 2009d, entire). Wind, geothermal, solar and biomass are
renewable energy sources developable in sage-grouse habitats. Large-
scale hydropower generation occurs in the sage-grouse range in parts of
Washington State. Conventional hydropower electrical generation has
actually decreased over the past 10 years (EIA 2009d, entire). In
general, growth of the renewable energy industry is predictable based
on legislated mandates to achieve target levels of renewable-produced
electricity in many States within the sage-grouse range.
Wind
Areas of commercially viable wind generation have been identified
by the NREL (2008b, entire) and BLM (2005, p.
[[Page 13950]]
2.4) in all 11 States in the greater sage-grouse range.
MZs III through VII each have approximately 1 to 14 percent of
sagebrush habitats that are commercially developable for wind energy
(Service 2008e, entire). Wind harvesting potentials are more
concentrated and geographically extensive in sage-grouse MZs I and II
that include parts of Montana, Wyoming, North Dakota, and South Dakota;
areas of highest commercial potential include 59 percent of the
available sagebrush habitats in these four States. Over 30 percent of
the sagebrush lands in the sage-grouse range have high potential for
wind power (Table 8).
Table 8--Area of sagebrush habitat with wind energy development
potential, by Management Zone. (Data from Service 2008e)
------------------------------------------------------------------------
Area of Sagebrush with Developable Wind
Potential
SAGE-GROUSE MZ --------------------------------------------
km\2\ mi\2\ Percent of MZ
------------------------------------------------------------------------
I 137,733 53,179 76.02
------------------------------------------------------------------------
II 46,835 18,083 42.16
------------------------------------------------------------------------
III 3,028 1,169 3.23
------------------------------------------------------------------------
IV 12,952 5,001 9.05
------------------------------------------------------------------------
V 5,532 2,136 8.27
------------------------------------------------------------------------
VI 2,660 1,027 14.44
------------------------------------------------------------------------
VII 199 77 1.10
------------------------------------------------------------------------
TOTAL 208,939 80,672 33.02
------------------------------------------------------------------------
Commercial viability is based on wind intensity and consistency,
available markets and access to transmission facilities. Consequently,
current development is focused in areas with existing power
transmission infrastructure associated with urban development,
preexisting conventional energy resource development (e.g., coal and
natural gas) and power generation. Growth of wind power development is
expected to continue even in the current economic climate (EIA 2009b,
p. 3), spurred by statutory mandates or financial incentives to use
renewable energy sources in all 11 States in the range (Association of
Fish and Wildlife Agencies (AFWA) and Service 2007, pp. 7, 8, 14, 28,
30, 36, 39, 43, 46, 49, 52; State of Oregon 2008, entire).
Wind generating facilities have increased in size and number,
outpacing development of other renewable sources in the sage-grouse
range. The BLM, the major land manager in the sage-grouse range,
developed programmatic guidance to facilitate the use of BLM land for
wind development (BLM 2005a, entire). The BLM wind policy permits
granting private right-of-ways and leasing of public land for 3-year
monitoring and testing facilities and long-term (30 to 35 years)
commercial generating facilities (American Wind Energy Association
(AWEA) 2008, p. 4-24). Active leases for wind energy development on BLM
lands increased from 9.7 km\2\ (3.7 mi\2\) in 2002 to 5,113 km\2\
(1,973 mi\2\) in 2008, and an additional 5,381 km\2\ (2,077 mi\2\) of
lease requests were pending approval in the sage-grouse range (Knick et
al., in press, p. 136).
A recent increase in wind energy development is most notable within
the range of the south-central Wyoming subpopulation of greater sage-
grouse in MZ II where 1,387 km\2\ (535 mi\2\) have active wind leases
and an additional 2,828 km\2\ (1,092 mi\2\) are pending (Knick et al.,
in press, p. 136). The south-central Wyoming subpopulation has a loose
association with adjacent populations where there is accelerated oil,
gas, and coal development in the State - the Powder River Basin (MZ I)
to the northeast and Pinedale-Jonah Gas Fields in the southwest Wyoming
Basin (MZ II) (Connelly et al. 2004, p. 6-62). As stated previously,
the Powder River Basin is home to an important regional population of
the larger Wyoming Basin populations (Connelly et al. 2004, p. 6-62).
The subpopulation in southwest Wyoming and northwest Colorado is a
stronghold for sage-grouse with some of the highest estimated densities
of males anywhere in the remaining range of the species (Connelly et
al. 2004, pp. 6-62, A5-23). The south-central Wyoming wind potential
corridor is not only a geographical bridge between two important
population areas but is home to a large population of sage-grouse
(Connelly et al. 2004, p. A5-22) and core areas identified
preliminarily as high density breeding areas for sage-grouse by the
Wyoming State Governor's Executive Order (State of Wyoming 2008,
entire). Although regulatory mechanisms are being developed for
Wyoming's core areas (see regulatory mechanisms section below), they
are still largely subject to the impacts of both conventional and
renewable energy development. Twenty-one percent of Wyoming core areas
have high wind development potential, and 51 percent are subject to
either wind or authorized development of oil and gas leases (Doherty et
al., in press, p. 31).
In addition to Wyoming, southeastern Oregon is a focus area for
potential commercial-scale wind development. Currently, south-central
and southeastern Oregon have large areas of relatively unfragmented
sage-dominated landscapes which are important for maintaining long-term
connectivity between the sage-grouse populations (Knick and Hanser, in
press, pp. 1-2.). Historically, central Oregon's population provided
connectivity with the Columbia Basin area through narrow habitat
corridors (Connelly et al. 2004, p. 6-13). These connections have now
been lost, resulting in the isolation of the northern extant population
in Washington. The Northern Great Basin ranks lowest of the MZs in the
intensity of the human footprint and consequent effects (Leu and
Hanser, in press, p. 25; Wisdom et al., in press, p. 16), and this
could be contributing to the substantial connectivity that still exists
between the Northern Great Basin, Snake River Plain, and the Southern
Great Basin
[[Page 13951]]
Region populations (Knick and Hanser, in press, p. 1). The BLM is the
major land manager in this part of the southeastern Oregon, with
jurisdiction over 49,000 km\2\ (18,900 mi\2\) (BLM 2009d, entire) that
include much of the scantily vegetated ridge tops prone to high and
sustained wind. At this time, most of the development activity is in
the initial phase of meteorological site investigation and involves
little infrastructure (AWEA 2009, entire; BLM 2009e). Many of these
monitoring sites could be developed, considering the projected demand
for renewable energy, contributing to fragmentation of this relatively
intact sagebrush landscape.
Most published reports of the effects of wind development on birds
focus on the risks of collision with towers or turbine blades. No
published research is specific to the effects of wind farms on the
greater sage-grouse. However, the avoidance of human-made structures
such as powerlines and roads by sage-grouse and other prairie grouse is
documented (Holloran 2005, p. 1; Pruett et al, in press, p. 6).
Renewable energy facilities, including wind power, typically require
many of the same features for construction and operation as do
nonrenewable energy resources. Therefore, we anticipate that potential
impacts from direct habitat losses, habitat fragmentation through roads
and powerlines, noise, and increased human presence (Connelly et al.
2004, pp. 7-40 to 7-41) will generally be similar to those already
discussed for nonrenewable energy development.
Wind farm development begins with site monitoring and collection of
meteorological data to accurately characterize the wind regime.
Turbines are installed after the meteorological data indicate the
appropriate siting and spacing. Roads are necessary to access the
turbine sites for installation and maintenance. Each turbine unit has
an estimated footprint of 0.4 to 1.2 ha (1 to 3 ac) (BLM 2005a, pp.
3.1-3.4). One or more substations may be constructed depending on the
size of the farm. Substation footprints are 2 ha (5 ac) or less in size
(BLM 2005a, p. 3.7).
The average footprint of a turbine unit is relatively small from a
landscape perspective. Turbines require careful placement within a
field to avoid loss of output from interference with neighboring
turbines. Spacing improves efficiency but expands the overall footprint
of the field. Sage-grouse populations are impacted by the direct loss
of habitat, primarily from construction of access roads as well as
indirect loss of habitat due to avoidance. Sage-grouse could be killed
by flying into turbine rotors or towers (Erickson et al. 2001, entire)
although reported collision mortalities have been few. One sage-grouse
was found dead within 45 m (148 ft) of a turbine on the Foote Creek Rim
wind facility in south-central Wyoming, presumably from flying into a
turbine (Young et al. 2003, Appendix C, p. 61). This is the only known
sage-grouse mortality at this facility during three years of
monitoring. Sage-grouse hens with broods have been observed under
turbines at Foote Creek Rim (Young 2004, pers. comm.). We have no
recent reports of sage-grouse mortality due to collision with a wind
turbine; however, many facilities may not be monitored. No deaths of
gallinaceous birds were reported in a comprehensive review of avian
collisions and wind farms in the United States; the authors
hypothesized that the average tower height and flight height of grouse,
and diurnal migration habitats of some birds minimized the risk of
collision (Johnson et al. 2000, pp. ii-iii; Erickson et al. 2001, pp.
8, 11, 14, 15).
Noise is produced by wind turbine mechanical operation (gear boxes,
cooling fans) and airfoil interaction with the atmosphere. No published
studies have focused specifically on the effects of wind power noise
and greater sage-grouse. In studies conducted in oil and gas fields,
noise may have played a factor in habitat selection and decrease in lek
attendance (Holloran 2005, pp. 49, 56). However, comparison between
wind turbine and oil and gas operations is difficult based on the
character of sound. Adjusting for manufacturer type and atmospheric
conditions, the audible operating sound of a single wind turbine has
been calculated as the same level as conversational speech at 1 m (3
ft) at a distance of 600 m (2,000 ft) from the turbine. This level is
typical of background levels of a rural environment (BLM 2005a, p. 5-
24). However, commercial wind farms do not have a single turbine, and
multiple turbines over a large area would likely have a much larger
noise print. Low-frequency vibrations created by rotating blades
produce annoyance responses in humans (van den Berg 2003, p. 1), but
the specific effect on birds is not documented.
Moving blades of turbines cast moving shadows that cause a
flickering effect producing a phenomenon called ``shadow flicker''
(AWEA 2008, p. 5-33). Hypothetically, shadow flicker could mimic
predator shadows and elicit an avoidance response in birds during
daylight hours, but this potential effect has not been investigated.
Since 2005, states have required an increasing amount of energy to
come from renewable sources. For example, Colorado law requires
incremental increases of renewable generation from 3 percent in 2007 to
20 percent by 2020 (AFWA and Service 2007, p. 8). Financial incentives,
including grants and tax breaks, encourage private development of
renewable sources. Although development of renewables is encouraged at
a State level, siting authority for wind varies from State to State
(AFWA and Service 2007, pp. 7, 8, 14, 28, 30, 36, 39, 43, 46, 49, 52;
State of Oregon 2008, entire). For example, the State of Idaho provides
tax incentives and loan programs for renewable energy development, but
wind power is currently unregulated at any level of government (AFWA
and Service 2007, p. 14). The North Dakota Public Service Commission
regulates siting of wind power facilities over 100 megawatts using the
Service's interim voluntary guidelines (Service 2003, entire).
Wyoming does not have a requirement for increased reliance on
renewable energy sources and no specific wind siting authority.
However, large construction projects in the State are subject to
approval by an Industrial Siting Council (ISC) of the State Department
of Environmental Quality, with the WGFD providing recommendations for
mitigating impacts to wildlife associated with development considered
by the ISC. The ISC's review and approval of projects is subject to the
Wyoming Governor's executive order (State of Wyoming 2008, entire) that
is intended to prevent harmful effects to sage-grouse from development
or new land uses in designated core areas. Wind developers in Wyoming
understand that most proposed wind developments regardless of locale
must be approved by the ISC and that development proposed in core areas
is unlikely to be permitted by the ISC due to the Governor's Executive
Order (see discussion in Factor D below).
The BLM manages more land areas of high wind resource potential
than any other land management agency. In 2005, the BLM completed the
Wind Energy Final Programmatic EIS that provides an overarching
guidance for wind project development on BLM-administered lands (BLM
2005a, entire). Best management practices (BMPs) are prescribed to
minimize impacts of all phases of construction and operation of a wind
production facility. The BMPs guide future project planning and do not
guarantee protections specific to sage-grouse. We do not have
information on how or where the EIS guidance has been applied since
2005 and cannot evaluate its effectiveness. The footprint of wind
energy developments is reported to be
[[Page 13952]]
small (BLM 2005a, p. 5-2). The BLM indicates that approximately 600
km\2\ (232 mi\2\) of BLM-administered lands are likely to be developed
in nine States within the sage-grouse's range before 2025 (BLM 2005a,
pp. ES-8, 5-2). It is estimated that only 5 to 10 percent of a
development will have a long-term disturbance that remains on the
landscape for at least as long as the generating facility is viable
(i.e., roads, foundations, substation, fencing) (BLM 2005a, p. 5-2).
However, this estimate does not account for sage-grouse avoidance of
developed areas and could be an underestimation of indirect effects.
Based on what we know of oil and gas development (previously
described), the impact of structures, noise and human activity can
reach far beyond the point of origin and contribute cumulatively to
other human-made and natural disturbances that fragment and decrease
the quality of sage-grouse habitats. The BLM's determination of the
quantity of lands potentially impacted by wind energy development could
be extremely conservative considering the interest in reducing green-
house emissions and the institution of State renewable energy mandates
and incentives that have occurred since 2005.
Wind development is guided by policy at BLM national and State
levels that generally offers only guidance to avoid impacts to sage-
grouse and habitats. A 2008 BLM Instruction Memo IM 2009-43 (BLM 2008e,
p. 2) emphasizes the use of the Service's 2003 interim guidelines as
voluntary and to be used only on a general basis in siting, design, and
monitoring decisions. The BLM's Oregon State Office Instruction
Memorandum OR-2008-014 (BLM 2007d, entire) is explicit in the placement
of meteorological test towers to avoid active leks, seasonal
concentrations, and collision; IM OR-2009-038 (BLM 2009f, entire)
reduces the ODFW's recommended buffer distance for wind farms and
applies only guidelines for avoidance of sage-grouse leks and seasonal
habitats.
Wind energy resources are found throughout the range of the greater
sage-grouse, and growth of wind power development is expected to
continue. The DOE predicts that wind may provide a significant portion
of the nation's energy needs by the year 2030, and substantial growth
of wind developments will be required (DOE 2008, p. 1). In mid-2009,
wind energy production facilities in the sage-grouse range in operation
or under construction had a capacity of 11.93 gigawatts (AWEA 2009,
entire) (Table 9). To achieve predicted levels of 49 to greater than 90
gigawatts capacity (DOE 2008, p. 10), the generation capacity will need
to increase by 400 to 800 percent by 2030. Existing commercial wind
turbines range from 1-2 megawatt generating capacity (AWEA 2009,
entire). The forecasted increase in production would require
approximately 37,000 to 78,000 or more turbines based on the existing
technology and equipment in use. Assuming a generation capacity of 5
megawatts per km\2\ (0.4 mi\2\) density, Copeland et al. (2009, p. 1)
estimated an additional 50,000 km\2\ (19,305 mi\2\) of land in the
sage-grouse range would be required to meet the predicted level of
wind-generated electricity by 2030.
Table 9-- Wind energy development in the greater sage-grouse range, 2009-2030.
--------------------------------------------------------------------------------------------------------------------------------------------------------
STATE MZ Existing Capacity 2009* (gigawatts) Forecasted Capacity in 2030 (gigawatts)**
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Dakota I 1.2 1 to 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
South Dakota I 0.31 5 to 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Montana I 0.17 5 to 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Wyoming I, II 1.3 10 plus
--------------------------------------------------------------------------------------------------------------------------------------------------------
Utah II, III, IV, VII 0.4 1 to 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Idaho IV 0.15 1 to 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nevada III, IV, V 0 5 to 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
California III, V 2.8 10 plus
--------------------------------------------------------------------------------------------------------------------------------------------------------
Oregon IV, V 2.2 5 to 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Washington VI 2.2 5 to 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Colorado II, VII 1.2 1 to 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total 11.93 49 to 90 plus
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Includes completed and under construction, Source: American Wind Energy Assn. (2009, entire).
** Source: DOE (2008, p. 10).
(1000 megawatt = 1 gigawatt)
States such as Nevada and Montana that have not been tapped for
extensive wind power development are likely to experience significant
new energy development within the next 20 years (Table 9). In Wyoming,
where wind development is advancing and predicted to increase by 10
fold or more (Table 9), the effects of both conventional and
nonconventional renewable sources may claim a substantial toll on sage-
grouse habitats and geographic areas that were in the past considered
refugia for the species. As with oil and gas development, the average
footprint of a turbine unit is relatively small from a landscape
perspective, but the effects of large-scale developments have the
potential to reduce the size of sagebrush habitats directly, degrade
habitats with invasive species, provide pathways for synanthropic
predators (i.e., predators that live near and benefit from an
association with humans), and cumulatively contribute to habitat
fragmentation.
[[Page 13953]]
Other Renewable Energy Sources
Hydropower development can cause direct habitat losses and possibly
an increase in human recreational activity. Reservoirs created
concurrently with power generation structures inundated large areas of
riparian habitats used by sage-grouse broods (Braun 1998, p. 144).
Reservoirs and the availability of irrigation water precipitated
conversion of large expanses of upland shrub-steppe habitat in the
Columbia Basin adjacent to the rivers (65 FR 51578, August 24, 2000).
We were unable to find any information regarding the amount of sage-
grouse habitat affected by hydropower projects in other areas of the
species' range beyond the Columbia Basin. No new large-scale facilities
have been constructed and hydropower electricity generation has
decreased steadily over the past 10 years (EIA 2009d, entire). We do
not anticipate that future dam construction will result in large losses
of sagebrush habitats.
Solar-powered electricity generation is increasing. Between 2005
and the end of 2008, solar electricity generation increased from the
equivalent of 66 trillion Btu to 83 trillion Btu (EIA 2009d, entire).
Solar-generating systems have been used on a small scale to power
individual buildings, small complexes, remote facilities, and signs.
Solar energy infrastructure is often ancillary to other development,
and large-scale solar-generating systems have not contributed to any
calculable direct habitat loss for sage-grouse, but this may change as
more systems come on line for commercial electricity generation. Solar
energy systems require, depending on local conditions, 1.6 ha (4 ac) to
produce 1 megawatt of electricity. For example, the 162-ha (400-ac)
Nevada Solar One, the third largest solar electricity producer in the
world, has a maximum potential of 75 megawatts from a 121-ha (300-ac)
solar field (nevadasolarone.com 2008, entire).
No commercial solar plants are operating in sage-grouse habitats at
this time. Southern and eastern Nevada, the Pinedale area of Wyoming,
and east-central Utah are the areas of the sage-grouse range with good
potential for commercial solar development (EIA 2009e, entire). There
are a total of 196 ha (484 ac) of active solar leases on BLM property
in northern California (MZ IV) and central Wyoming (MZ II) (BLM 2009g,
map) in sagebrush habitats within the current sage-grouse range and
these leases will likely be developed. The BLM is developing a
programmatic EIS for leasing and development of solar energy on BLM
lands. The EIS planning period has been extended to analyze the effects
of concentrating large-scale development in selected geographic areas
including sage-grouse habitats in east-central Nevada and southern Utah
(BLM 2009h, entire) because of the considerable administrative and
public interest in developing public lands for solar-generated
electricity (BLM 2009i, entire). At this time, we do not have enough
information available to evaluate the scale of future impacts of solar
power generation in sage-grouse habitats. We will continue to evaluate
and monitor the impacts of solar power development in sage-grouse
habitats as more information becomes available. We are not aware of any
investigations reporting the impacts of solar generating facilities on
sage-grouse or other gallinaceous birds. Commercial solar generation
could produce direct habitat loss (i.e., solar fields completely
eliminate habitat), fragmentation, roads, powerlines, increased human
presence, and disturbance during facility construction with similar
effects to sage-grouse as reported with oil and gas development.
Geothermal energy production has remained steady since 2005 (EIA
2009d, entire). Geothermal facilities are within the sage-grouse range
in California (3 plants, MZ III), Nevada (5 plants, MZs III and V),
Utah (2 plants, MZ III), and Idaho (1 plant, MZ IV). Since 2005, two
additional plants were constructed is in current sage-grouse range -
one in Idaho and one in Utah (Geothermal Energy Association 2008, pp.
2-7). One existing geothermal plant in southern Utah is in the vicinity
of sage-grouse habitat in an area where wind power is being considered
for development (First Wind-Milford 2009, entire), which will result in
cumulative impacts. Geothermal potential occurs across the sage-grouse
range in States with existing development and southeast Oregon, west-
central Wyoming, and north-central Colorado (EIA 2009e, entire).
Geothermal energy production is similar to oil and gas development
such that it requires surface exploration, exploratory drilling, field
development, and plant construction and operation. Wells are drilled to
access the thermal source and could take from 3 weeks to 2 months of
continuous drilling (Suter 1978, p. 3), which may cause disturbance to
sage-grouse. The ultimate number of wells, and therefore potential loss
of habitat, depends on the thermal output of the well and expected
production of the plant (Suter 1978, p. 3). Pipelines are needed to
carry steam or superheated liquids to the generating plant which is
similar in size to a coal- or gas-fired plant, resulting in further
habitat and indirect disturbance. Direct habitat loss occurs from well
pads, structures, roads, pipelines and transmission lines, and impacts
would be similar to those described previously for oil and gas
development.
The development of geothermal energy requires intensive human
activity during field development and operation. Geothermal plants
could be in remote areas necessitating housing construction,
transportation, and utility infrastructure for employees and their
families (Suter 1978, p. 12). Geothermal development could cause toxic
gas release; the type and effect of these gases depends on the
geological formation in which drilling occurs (Suter 1978, pp. 7-9).
The amount of water necessary for drilling and condenser cooling may be
high. Local water depletions may be a concern if such depletions result
in the loss of brood-rearing habitat.
The BLM has the authority to lease geothermal resources in 11
western States. A programmatic EIS for geothermal leasing and
operations was completed in 2008 (BLM and USFS 2008a, entire). Best
management practices for minimizing the effects of geothermal
development and operations on sage-grouse are guidance only and are
general in nature (BLM and USFS 2008a, pp. 4.82-4.83). The EIS'
reasonably foreseeable development scenario predicts that Nevada will
experience the greatest increase in geothermal growth-doubling the
production of electricity from geothermal sources by 2025 (BLM and USFS
2008, p. 2-35). Currently, approximately 1,800 km\2\ (694 mi\2\) of
active geothermal leases exist on public lands primarily in the
Southern (MZ IV) and Northern Great Basin (MZ III) and 1,138 km\2\ (439
mi\2\) of leases are pending (Knick et al., in press, p. 138).
Energy production from biomass sources has increased every year
since 2005 (EIA 2009d, entire). Wood has been a primary biomass source,
but corn ethanol and biofuels produced from cultivated crops are on the
increase (EIA 2008b, entire). Currently, wood products and corn
production do not occur in the range of the sage-grouse in significant
quantities (Curtis 2008, p. 7). The National Renewable Energy
Laboratory cites potentials for agricultural biomass resources in
northern Montana (MZ I), southern Idaho (MZ IV), eastern Washington (MZ
VI), eastern Oregon MZ IV), northwest Nevada (MZ V), and southeast
Wyoming (MZ II) (NREL 2005, entire). Conversion from native sod to
agriculture for the purpose of biomass production could result in a
loss of sage-grouse habitat on
[[Page 13954]]
private lands. The 2007 Energy Independence and Security Act mandated
incremental production and use through the year 2022 of advanced
biofuel, cellulosic biofuel, and biomass-based diesel (P.L. 110-140,
section 203) and could provide an incentive to convert native sod or
expired CRP lands to biomass crops. The effects on sage-grouse will
depend on amount and location of sagebrush habitats developed. The
effects of agriculture are discussed in habitat conversion section
above.
Transmission Corridors
Section 368(a) of the Energy Policy Act of 2005 (42 U.S.C. 15926)
directs Federal land management agencies to designate corridors on
Federal land in 11 western States for oil, gas and hydrogen pipelines
and electricity transmission and distribution facilities (energy
transport corridors). The agencies completed a programmatic EIS (DOE et
al. 2008, entire) to address the environmental impacts of corridors on
Federal lands. The proposed action calls for designating more than
9,600 km (6,000 mi) with an average width of 1 km (0.6 mi) of energy
corridors across the western United States (DOE et al. 2008, p. S-17).
The designated corridors on Federal lands will tie in to corridors on
private lands and lands in other governmental jurisdictions. Some of
the areas proposed for designation are currently used for transmission.
Federal lands newly incorporated into transportation or utility rights-
of-way are mostly BLM lands in California (185 km, 115 mi), Colorado
(97 km, 60 mi), Idaho (303 km, 188 mi), Montana (254 km, 158 mi),
Nevada (810 km, 503 mi), Oregon (418 km, 260 mi), Washington (no
additional land), Utah (356 km, 221 mi), and Wyoming (198 km, 123 mi)
(DOE et al. 2008, p. S-18).
It is uncertain how much of the proposed corridors are in sagebrush
habitat within the distribution area of sage-grouse, but based on the
proposed location, habitat in Wyoming (MZ II), Idaho (MZ IV), Utah (MZ
III), Nevada (MZ III) and Oregon (MZs III and IV) would be most
affected. The purpose of the corridor designation is to serve a role in
expediting applications to construct or modify oil, gas, and hydrogen
pipelines and electricity transmission and distribution. These
designated areas will likely facilitate the development of novel
renewable and nonrenewable electricity generating facilities on public
and private lands. Sage-grouse could be impacted through a direct loss
of habitat, human activity (especially during construction periods),
increased predation, habitat deterioration through the introduction of
nonnative plant species, and additional fragmentation of habitat.
Summary: Energy Development
Energy development is a significant risk to the greater sage-grouse
in the eastern portion of its range (Montana, Wyoming, Colorado, and
northeastern Utah - MZs I, II, VII and the northeastern part of MZ
III), with the primary concern being the direct effects of energy
development on the long-term viability of greater sage-grouse by
eliminating habitat, leks, and whole populations and fragmenting some
of the last remaining large expanses of habitat necessary for the
species' persistence. The intensity of energy development is cyclic and
based on many factors including energy demand, market prices, and
geopolitical uncertainties. However, continued exploration and
development of traditional and nonconventional fossil fuel sources in
the eastern portion of the greater sage-grouse range is predicted to
continue to increase over the next 20 years (EIA 2009b, p. 109).
Greater sage-grouse populations are predicted to decline 7 to 19
percent over the next 20 years due to the effects of oil and gas
development in the eastern part of the range (Copeland et al. 2009, p.
4); this decline is in addition to the 45 to 80 percent decline that is
estimated to have already occurred range wide (Copeland et al. 2009, p.
4).
Development of commercially viable renewable energy--wind, solar,
geothermal, biomass--is increasing across the range with focus in some
areas already experiencing traditional energy development (EIA 2009b,
pp. 3-4; AWEA 2009a, entire). In Wyoming, where wind development is
advancing and predicted to increase by 10-fold (DOE 2008, p. 10), the
effects of both conventional and nonconventional and renewable sources
may claim a substantial toll on sage-grouse habitats and geographic
areas that were in the past considered refugia for the species.
Renewable energy resources are likely to be developed in areas
previously untouched by traditional energy development. Wind energy
resources are being investigated in south-central and southeastern
Oregon where large areas of relatively unfragmented sage-dominated
landscapes are important for maintaining long-term connectivity within
the sage-grouse populations (Knick and Hanser in press, pp. 1-2.).
Greater sage-grouse populations are negatively affected by energy
development activities, even when mitigative measures are implemented
(Holloran 2005, pp. 57-60; Walker et al. 2007a, p. 2651). Energy
development, particularly high density development, will continue to
threaten sage-grouse populations, specifically in the MZs I and II,
which contain the greatest numbers of birds throughout their range.
Development of commercially viable renewable energy-wind, solar,
geothermal, biomass-is rapidly increasing rangewide with a focus in
some areas already experiencing significant traditional energy
development (e.g., MZs I and II). The effects of renewable energy
development are likely similar to those of nonrenewable energy as
similar types of infrastructure are required. Based on our review of
the literature, we anticipate the impacts of these developments will
negatively affect the ability of greater sage-grouse to persist in
those areas in the foreseeable future.
Climate Change
The Intergovernmental Panel on Climate Change (IPCC) has concluded
that warming of the climate is unequivocal, and that continued
greenhouse gas emissions at or above current rates will cause further
warming (IPCC 2007, p. 30). Eleven of the 12 years from 1995 through
2006 rank among the 12 warmest years in the instrumental record of
global surface temperature since 1850 (ISAB 2007). Climate-change
scenarios estimate that the mean air temperature could increase by over
3[deg]C (5.4[deg]F) by 2100 (IPCC 2007, p. 46). The IPCC also projects
that there will very likely be regional increases in the frequency of
hot extremes, heat waves, and heavy precipitation (IPCC 2007, p. 46),
as well as increases in atmospheric carbon dioxide (IPCC 2007, p. 36).
We recognize that there are scientific differences of opinion on
many aspects of climate change, including the role of natural
variability in climate. In our analysis, we rely primarily on synthesis
documents (e.g., IPCC 2007; Global Climate Change Impacts in the United
States 2009) that present the consensus view of a very large number of
experts on climate change from around the world. We have found that
these synthesis reports, as well as the scientific papers used in those
reports or resulting from those reports, represent the best available
scientific information we can use to inform our decision and have
relied upon them and provided citation within our analysis. In
addition, where possible we have used projections specific to the
region of interest, the western United States and southern Canada,
which includes the range of the greater sage-grouse. We also use
projections of the effects of climate
[[Page 13955]]
change to sagebrush where appropriate, while acknowledging that the
uncertainty of climate change effects increases as one applies those
potential effects to a habitat variable like sagebrush, and then
increases again when the impacts to the habitat variable are applied to
the species.
Projected climate change and its associated consequences have the
potential to affect greater sage-grouse and may increase its risk of
extinction, as the impacts of climate change interact with other
stressors such as disease, and habitat degradation and loss that are
already affecting the species (Walker and Naugle, in press, entire;
Global Climate Change Impacts in the United States 2009, p. 81; Miller
et al. in press, pp. 46-50). In the Pacific Northwest, regionally
averaged temperatures have risen 0.8 degrees Celsius (1.5 degrees
Fahrenheit) over the last century (as much as 2 degrees Celsius (4
degrees Fahrenheit) in some areas), and are projected to increase by
another 1.5 to 5.5 degrees Celsius (3 to 10 degrees Fahrenheit) over
the next 100 years (Mote et al. 2003, p. 54; Global Climate Change
Impacts in the United States 2009, p. 135). Arid regions such as the
Great Basin where greater sage-grouse occurs are likely to become
hotter and drier; fire frequency is expected to accelerate, and fires
may become larger and more severe (Brown et al. 2004, pp. 382-383;
Neilson et al. 2005, p. 150; Chambers and Pellant 2008, p. 31; Global
Climate Change Impacts in the United States 2009, p. 83).
Climate changes such as shifts in timing and amount of
precipitation, and changes in seasonal high and low temperatures, as
well as average temperatures, may alter distributions of individual
species and ecosystems significantly (Bachelet et al. 2001, p174).
Under projected future temperature conditions, the cover of sagebrush
within the distribution of sage-grouse is anticipated to be reduced
(Neilson et al. 2005, p. 154; Miller et al. in press, p. 45). Warmer
temperatures and greater concentrations of atmospheric carbon dioxide
create conditions favorable to Bromus tectorum, as described above,
thus continuing the positive feedback cycle between the invasive annual
grass and fire frequency that poses a significant threat to greater
sage-grouse (Chambers and Pellant 2008, p. 32; Global Climate Change
Impacts in the United States 2009, p. 83). Fewer frost-free days also
may favor frost-sensitive woodland vegetation of Sonoran and Chihuahuan
deserts, which may expand, potentially encroaching on the sagebrush
biome in the southern Great Basin where sage-grouse populations
currently exist (Miller et al. in press, p. 44). Such encroachment of
woody vegetation degrades sage-grouse habitat (see Factor A, Invasive
plants).
Temperature and precipitation both directly influence potential for
West Nile virus (WNv) transmission (Walker and Naugle in press, p. 12).
In sage-grouse, WNv outbreaks appear to be most severe in years with
higher summer temperatures (Walker and Naugle in press, p. 13) and
under drought conditions (Epstein and Defilippo, p. 105). This
relationship is due to the breeding cycle of the WNv vector, Culex
tarsalis being highly dependent on warm water temperature for mosquito
activity and virus amplification (Walker and Naugle in press, p. 12;
see discussion under Disease and Predation below). Therefore, the
higher summer temperatures and more frequent or severe drought or both,
that are likely under current climate change projections, make more
severe WNv outbreaks likely in low-elevation sage-grouse habitats where
WNv is already endemic, and also make WNv outbreaks possible in higher
elevation sage-grouse habitats that to date have been WNv-free due to
relatively cold conditions.
Emissions of carbon dioxide, considered to be the most important
anthropogenic greenhouse gas, increased by approximately 80 percent
between 1970 and 2004 due to human activities (IPCC 2007, p. 36).
Future carbon dioxide emissions from energy use are projected to
increase by 40 to 110 percent over the next few decades, between 2000
and 2030 (IPCC 2007, p. 44). An increase in the atmospheric
concentration of carbon dioxide has important implications for greater
sage-grouse, beyond those associated with warming temperatures, because
higher concentrations of carbon dioxide are favorable for the growth
and productivity of Bromus tectorum (Smith et al. 1987, p. 142; Smith
et al. 2000, p. 81). Although most plants respond positively to
increased carbon dioxide levels, many invasive nonnative plants respond
with greater growth rates than native plants, including B. tectorum
(Smith et al. 1987, p. 142; Smith et al. 2000, p. 81; Global Climate
Change Impacts in the United States 2009, p. 83). Laboratory research
results illustrated that B. tectorum grown at carbon dioxide levels
representative of current climatic conditions matured more quickly,
produced more seed and greater biomass, and produced significantly more
heat per unit biomass when burned than B. tectorum grown at ``pre-
industrial'' carbon dioxide levels (Blank et al. 2006, pp. 231, 234).
These responses to increasing carbon dioxide may have increased the
flammability in B. tectorum communities during the past century (Ziska
et al. 2005, as cited in Zouhar et al. 2008, p. 30; Blank et al. 2006,
p. 234).
Field studies likewise demonstrate that Bromus species demonstrate
significantly higher plant density, biomass, and seed rain (dispersed
seeds) at elevated carbon dioxide levels relative to native annuals
(Smith et al. 2000, pp. 79-81). The researchers conclude that ``the
results from this study confirm experimentally in an intact ecosystem
that elevated carbon dioxide may enhance the invasive success of Bromus
spp. in arid ecosystems,'' and suggest that this enhanced success will
then expose these areas to accelerated fire cycles (Smith et al. 2000,
p. 81). Chambers and Pellant (2008, p. 32) also suggest that higher
carbon dioxide levels are likely increasing B. tectorum fuel loads due
to increased productivity, with a resulting increase in fire frequency
and extent. Based on the best available information, we expect the
current and predicted atmospheric carbon dioxide levels to increase the
threat posed to greater sage-grouse by B. tectorum and from more
frequent, expansive, both in sage-grouse habitat degradation
(functional fragmentation) and severe wildfires (Smith et al. 1987, p.
143; Smith et al. 2000, p. 81; Brown et al. 2004, p. 384; Neilson et
al. 2005, pp. 150, 156; Chambers and Pellant 2008, pp. 31-32).
Therefore, beyond the potential changes associated with temperature and
precipitation, increases in carbon dioxide concentrations represent a
threat to the sagebrush biome and an indirect threat to sage-grouse
through habitat degradation and loss (Miller et al. in press, p. 45),
with the combined effects of higher temperatures and carbon dioxide
concentrations leading to a loss of 12 percent of the current area of
sagebrush per degree Celsius of temperature increase, or from 34 to 80
percent of sagebrush distribution depending on the emissions scenario
used (Nielson et al. 2005, p. 6, 10; Miller et al. in press, p. 45).
Bradley (2009, pp. 196-208) and Bradley et al. (2009, pp. 1-11)
predict that nonnative invasive species in the sagebrush-steppe
ecosystem may either expand or contract under climate change, depending
on the current and projected future range of a particular invasive
plant species. They developed a bioclimatic model for B. tectorum based
on maps of invaded range derived from remote sensing. The best
predictors of B. tectorum occurrence
[[Page 13956]]
were summer, annual, and spring precipitation, followed by winter
temperature (Bradley et al., 2009, p. 5). Depending primarily on future
precipitation conditions, the model predicts B. tectorum is likely to
shift northwards, leading to expanded risk of B. tectorum invasion in
Idaho, Montana, and Wyoming, but reduced risk of invasion in southern
Nevada and Utah, which currently have large areas dominated by this
nonnative grass (Bradley et al., 2009, p. 5). Therefore, the threat
posed to greater sage-grouse by the greater frequency and geographic
extent of wildfires and other associated negative impacts from the
presence of B. tectorum is expected to continue into the foreseeable
future. Bradley (2009, pp. 205) stated that the bioclimatic model she
used is an initial step in assessing the potential geographic extent of
B. tectorum, because climate conditions only affect invasion on the
broadest regional scale. Other factors relating to land use, soils,
competition, or topography may affect suitability of a given location.
Bradley (2009, entire) concludes that the potential for climate to
shift away from suitability for B. tectorum in the future may offer an
opportunity for restoration of the sagebrush biome in this area. We
anticipate that areas that become unsuitable for B. tectorum, may
transition to other vegetation over time. However, it is not known if
transition back to sagebrush as a dominant landcover or to other native
or nonnative vegetation is more likely.
In a study that modeled potential impacts to big sagebrush (A.
tridentata ssp.) due to climate change, Shafer et al. (2001, pp. 200-
215) used response surfaces to describe the relationship between
bioclimatic variables and the distribution of tree and shrub taxa in
western North America. Species distributions were simulated using
scenarios generated by three general circulation models - HADCM2,
CGCM1, and CSIRO. Each scenario produced similar results, simulating
future bioclimatic conditions that would reduce the size of the overall
range of sagebrush and change where sagebrush may occur. These
simulated changes were the result of increases in the mean temperature
of the coldest month which the authors speculated may interact with
soil moisture levels to produce the simulated impact. Each model
predicted that climate suitability for big sagebrush would shift north
into Canada. Areas in the current range would become less suitable
climatically, and would potentially cause significant contraction. The
authors also point out that increases in fire frequency under the
simulated climate projections would leave big sagebrush more vulnerable
to fire impacts.
Shafer et al. (2001, pp. 213) explicitly state that their approach
should not be used to predict the future range of a species, and that
the underlying assumptions of the models they used are ``unsatisfying''
because they presume a direct causal relationship between the
distribution of a species and particular environmental variables.
Shafer et al. (2001, pp. 207, 213) identify cautions similar to Bradley
et al. (in press, pp. 205) regarding their models. A variety of factors
are not included in climate space models, including: the effect of
elevated CO2 on the species' water-use efficiency, what really is the
physiological effect of exceeding the assumed (modeled) bioclimatic
limit on the species, the life stage at which the limit affects the
species (seedling versus adult), the life span of the species, and the
movement of other organisms into the species range (Shafer et al.,
2001, pp. 207). These variables would likely help determine how climate
change would affect species distributions. Shafer et al. (2001, pp.
213) concludes that while more empirical studies are needed on what
determines a species and multi-species distributions, those data are
often lacking; in their absence climatic space models can play an
important role in characterizing the types of changes that may occur so
that the potential impacts on natural systems can be assessed.
Schrag et al. (submitted MS, 2009, pp. 1-42) developed a
bioclimatic envelope model for big sagebrush and silver sagebrush in
the States of Montana, Wyoming, and North and South Dakotas. This
analysis suggests that large displacement and reduction of sagebrush
habitats will occur under climate change as early as 2030 for both
species of sagebrush examined. At the time of this finding, the Schrag
et al. analysis has not been peer reviewed, and we have significant
reservations about using analyses of this level of complexity in making
management decisions, without it having gone through a review process
where experts in the fields of climate change, bioclimatic modeling,
and sagebrush ecology can all assess the validity of the reported
results. Other models projecting the affect of climate change on
sagebrush habitat discussed more below, identify uncertainty associated
with projecting climatic habitat conditions into the future given the
unknown influence of other factors that such models do not incorporate
(e.g., local physiographic conditions, life stage of the plant,
generation time of the plant and its reaction to changing CO2 levels).
In some cases, effects of climate change can be demonstrated (e.g.,
McLaughlin et al. 2002) and where it can be, we rely on that empirical
evidence, such as increased stream temperatures (see Rio Grande
cutthroat trout, 73 FR 27900), or loss of sea ice (see polar bear, 73
FR 28212), and treat it as a threat that can be analyzed. However, we
have no such data relating to greater sage-grouse. Application of
continental scale climate change models to regional landscapes, and
even more local or ``step-down'' models projecting habitat potential
based on climatic factors, while informative, contain a high level of
uncertainty due to a variety of factors including: regional weather
patterns, local physiographic conditions, life stages of individual
species, generation time of species, and species reactions to changing
CO2 levels. The models summarized above are limited by these types of
factors; therefore, their usefulness in assessing the threat of climate
change on greater sage-grouse also is limited.
Summary: Climate Change
The direct, long-term impact from climate change to greater sage-
grouse is yet to be determined. However, as described above, the
invasion of Bromus tectorum and the associated changes in fire regime
currently pose one of the significant threats to greater sage-grouse
and the sagebrush-steppe ecosystem. Under current climate-change
projections, we anticipate that future climatic conditions will favor
further invasion by B. tectorum, as well as woody invasive species that
affect habitat suitability, and that fire frequency will continue to
increase, and the extent and severity of fires may increase as well.
Climate warming is also likely to increase the severity of WNv
outbreaks and to expand the area susceptible to outbreaks into areas
that are now too cold for the WNv vector. Therefore, the consequences
of climate change, if current projections are realized, are likely to
exacerbate the existing primary threats to greater sage-grouse of
frequent wildfire and invasive nonnative plants, particularly B.
tectorum as well as the threat posed by disease. As the IPCC projects
that the changes to the global climate system in the 21st century will
likely be greater than those observed in the 20th century (IPCC 2007,
p. 45), we anticipate that these effects will continue and likely
increase into the foreseeable future. As there is some degree of
uncertainty regarding the potential effects of climate
[[Page 13957]]
change on greater sage-grouse specifically, climate change in and of
itself was not considered a significant factor in our determination
whether greater sage-grouse is warranted for listing. However, we
expect the severity and scope of two of the significant threats to
greater sage-grouse, frequent wildfire and B. tectorum colonization and
establishment; as well as epidemic WNv, to magnify within the
foreseeable future due the effects of climate change already underway
(i.e., increased temperature and carbon dioxide). Thus, currently we
consider climate change as playing a potentially important indirect
role in intensifying some of the current significant threats to the
species.
Analysis of Habitat Fragmentation in the Context of Factor A
Greater sage-grouse are a landscape-scale species requiring large,
contiguous areas of sagebrush for long-term persistence. Large-scale
characteristics within surrounding landscapes influence habitat
selection, and adult sage-grouse exhibit a high fidelity to all
seasonal habitats, resulting in little adaptability to changes.
Fragmentation of sagebrush habitats has been cited as a primary cause
of the decline of sage-grouse populations (Patterson 1952, pp. 192-193;
Connelly and Braun 1997, p. 4; Braun 1998, p. 140; Johnson and Braun
1999, p. 78; Connelly et al. 2000a, p. 975; Miller and Eddleman 2000,
p. 1; Schroeder and Baydack 2001, p. 29; Johnsgard 2002, p. 108;
Aldridge and Brigham 2003, p. 25; Beck et al. 2003, p. 203; Pedersen et
al. 2003, pp. 23-24; Connelly et al. 2004, p. 4-15; Schroeder et al.
2004, p. 368; Leu et al. in press, p. 19). Documented negative effects
of fragmentation include reduced lek persistence, lek attendance,
population recruitment, yearling and adult annual survival, female nest
site selection, nest initiation, and loss of leks and winter habitat
(Holloran 2005, p. 49; Aldridge and Boyce 2007, pp. 517-523; Walker et
al. 2007a, pp. 2651-2652; Doherty et al. 2008, p. 194). Functional
habitat loss also contributes to habitat fragmentation as greater sage-
grouse avoid areas due to human activities, including noise, even
though sagebrush remains intact. In an analysis of population
connectivity, Knick and Hanser (in press, p. 31) demonstrated that in
some areas of the sage-grouse range, populations are already isolated
and at risk for extirpation due to genetic, demographic, and
environmental stochasticity. Habitat loss and fragmentation contribute
to this population isolation and increased risk of extirpation.
We examined several factors that result in habitat loss and
fragmentation. Historically, large losses of sagebrush habitats
occurred due to conversion for agricultural croplands. This conversion
is continuing today, and may increase due to the promotion of biofuel
production and new technologies to provide irrigation to arid lands.
Indirect effects of agricultural activities, such as linear corridors
created by irrigation ditches, also contribute to habitat fragmentation
by allowing the incursion of nonnative plants. Direct habitat loss and
fragmentation also has occurred as the result of expanding human
populations in the western United States, and the resulting urban
development in sagebrush habitats.
Fire is one of the primary factors linked to population declines of
greater sage-grouse because of long-term loss of sagebrush and
conversion to nonnative grasses. Loss of sagebrush habitat to wildfire
has been increasing in the western portion of the greater sage-grouse
range due to an increase in fire frequency and size. This change is the
result of incursion of nonnative annual grasses, primarily Bromus
tectorum, into sagebrush ecosystems. The positive feedback loop between
B. tectorum and fires facilitates future fires and precludes the
opportunity for sagebrush, which is killed by fire, to become re-
established. B. tectorum and other invasive plants also alter habitat
suitability for sage-grouse by reducing or eliminating native forbs and
grasses essential for food and cover. Annual grasses and noxious
perennials continue to expand their range, facilitated by ground
disturbances, including wildfire, grazing, agriculture, and
infrastructure associated with energy development and urbanization.
Concern with habitat loss and fragmentation due to fire and invasive
plants has mostly been focused in the western portion of the species'
range. However, climate change may alter the range of invasive plants,
potentially expanding this threat into other areas of the species'
range. The establishment of these plants will then contribute to
increased fire frequency in those areas, further compounding habitat
loss and fragmentation. Functional habitat loss is occurring from the
expansion of native conifers, mainly due to decreased fire return
intervals, livestock grazing, increases in global carbon dioxide
concentrations, and climate change.
Sage-grouse populations are significantly reduced, including local
extirpation, by nonrenewable energy development activities, even when
mitigative measures are implemented (Walker et al. 2007a, p. 2651). The
persistent and increasing demand for energy resources is resulting in
their continued development within sage-grouse range, and will only act
to increase habitat fragmentation. Habitat fragmentation due to energy
development results not only from the actual footprint of energy
development and its appurtenant facilities (e.g., powerlines, roads),
but also from functional habitat loss (e.g., noise, presence of
overhead structures).
Livestock management and domestic livestock and wild horse grazing
have the potential to seriously degrade sage-grouse habitat at local
scales through loss of nesting cover, decreasing native vegetation, and
successional stage and, therefore, vegetative resiliency, and
increasing the probability of incursion of invasive plants. Fencing
constructed to manage domestic livestock causes direct mortality,
degradation, and fragmentation of habitats, and increased predator
populations. There is little direct evidence linking grazing practices
to population levels of greater sage-grouse. However, testing for
impacts of grazing at landscape scales important to sage-grouse is
confounded by the fact that almost all sage-grouse habitat has at one
time been grazed, and thus no non-grazed areas currently exist with
which to compare. While some rangeland treatments to remove sagebrush
for livestock forage production can temporarily increase sage-grouse
foraging areas, the predominant effect is habitat loss and
fragmentation, although those losses cannot be quantified or spatially
analyzed due to lack of data collection.
Restoration of sagebrush habitat is challenging, and restoring
habitat function may not be possible because alteration of vegetation,
nutrient cycles, topsoil, and cryptobiotic crusts have exceeded
recovery thresholds. Even if possible, restoration will require decades
and will be cost-prohibitive. To provide habitat for sage-grouse,
restoration must include all seasonal habitats and occur on a large
scale (4,047 ha (10,000 ac) or more) to provide all necessary habitat
components. Restoration may never be achieved in the presence of
invasive grass species.
The WAFWA identified a goal of ``no net loss'' of birds and habitat
in their Greater Sage-grouse Comprehensive Conservation Strategy
(Stiver et al. 2006, p. 1-7). Knick and Hanser (in press, p. 32) have
concluded that this strategy may no longer be possible due to natural
and anthropogenic threats that are degrading the remaining sagebrush
habitats. They recommend focusing conservation on areas critical to
range-wide persistence of this species (Knick and Hanser in press, p.
31). Wisdom et al. (in press, pp. 24-25) and
[[Page 13958]]
Knick and Hanser (in press, p. 17) identified two strongholds of
contiguous sagebrush habitat essential for the long-term persistence of
greater sage-grouse (the southwest Wyoming Basin and the Great Basin
area straddling the States of Oregon, Nevada, and Idaho). Other areas
within the greater sage-grouse range had a high uncertainty for
continued population persistence (Wisdom et al., in press, p. 25) due
to fragmentation from anthropogenic impacts. However, our analyses of
fragmentation in the two stronghold areas showed that habitats in these
areas are becoming fragmented due to wildfire, invasive species, and
energy development. Therefore, we are concerned that the level of
fragmentation in these areas may already be limiting sage-grouse
populations and further reducing connectivity between populations.
These threats have intensified over the last two decades, and we
anticipate that they will continue to accelerate due to the positive
feedback loop between fire and invasives and the persistent and
increasing demand for energy resources.
Population Trends in Relation to Habitat Loss and Fragmentation
In order to assess the effects of habitat loss and fragmentation on
greater sage-grouse populations and persistence, we examined a variety
of data to understand how population trends reflected the changing
habitat condition. Patterns of sage-grouse extirpation were identified
by Aldridge et al. 2008 (entire) Johnson et al. (in press, entire),
Wisdom et al. (in press, entire), Knick and Hanser (in press, entire),
and others, and discussed in detail above. Examples include
fragmentation of populations and their isolation as a result of habitat
loss from fire (Knick and Hanser in press, p. 20; Wisdom et al. in
press, p. 22), an increase in the probability of extirpation as a
result of fire (Knick and Hanser in press, p. 31) and agricultural
activities and human densities (Aldridge et al. 2008, p. 990; Wisdom et
al. in press, p. 4), and sage-grouse population declines as a result of
energy development (Doherty et al. 2008, p. 193; Johnson et al. in
press, p. 13; Leu and Hanser, in press, p. 28). Therefore, where these
habitat factors, and others identified above, are occurring, we
anticipate that sage-grouse population trends will continue to decline.
Lek count data are the only data available to estimate sage-grouse
population trends, and are the data WAFWA collects (WAFWA 2008, p. 3).
The use of lek count data as an index of trends involves various types
of uncertainty (such as measurement error, count methods, statistical
and other types of assumptions; e.g. see Connelly et al., 2004, pp. 6-
18 to 6-20; and WAFWA 2008, pp. 7-8). Nevertheless, these data have
been collected for 50 years in most locations and therefore do have
utility in examining long-term trends (Gerrodette 1987, p. 1370;
Connelly et al. 2004, p. A3-3; Stiver et al. 2009, p. 3-5; WAFWA 2008,
p. 3), and in evaluating differences in trends across the species'
range. Therefore, we are considering the results of researchers whose
work relies on lek data (e.g., Garton et al. (in press), Wisdom et al.
(in press), Connelly et al. (2004, p. 6-18 to 6-59; WAFWA 2008, entire)
to help inform our overall analyses.
Population trends (average number of males per lek) in MZs I and
II, the areas with the highest concentration of nonrenewable energy
development, decreased by 17 and 30 percent from 1965 to 2007,
respectively (Garton et al. in press, pp. 28, 35). Individual
population trends within each MZ varied. However, in areas of intensive
energy development, trends were negative as habitat continued to be
fragmented. For example, in the Powder River Basin of Wyoming, sage-
grouse populations have declined by 79 percent in the 12 years since
coal-bed methane development was initiated there (Emmerich 2009, pers.
comm.). In MZs affected by Bromus tectorum and fire, (primarily MZs IV
(Snake River Plain) and V (Northern Great Basin)), population trends
from 1995 to 2007 also were negative (Table 6). These results are
consistent with the analyses conducted by Wisdom et al. (in press, p.
24) that demonstrate that fragmentation as a result of disturbance
results in reduced population numbers and population isolation.
In some populations within the species' range, population trends
(number of males counted on leks) since the early 1990s appear to be
stable, and in some cases increasing (Garton et al. in press, Figs.2-8,
pp.188-219). However, simply looking at total number of males counted
does not accurately reflect habitat conditions, as leks, and by
inference the associated breeding habitats, could have been lost.
Additionally, as discussed above, sage-grouse will continue to attend
leks even after habitat suitability is diminished simply due to site
fidelity (Walker et al. 2007a, p. 2651). Therefore, the counts of males
on these leks may artificially minimize the declines seen in trend
analyses, as little productivity results from them. Because the
analyses were truncated in 2007 to be comparable to other analyses of
population trends (i.e. Connelly et al. 2004 and WAFWA 2008, see
discussion under population size above), delays in population response
to habitat loss and fragmentation events within the past 2 to 3 years
may not have been captured. Also, some significant events that have
resulted in habitat loss occurred after the 2007 lekking season. For
example, the Murphy complex fire in Idaho and Nevada burned 264,260 ha
(653,000 ac), resulting in the loss of 75 of 102 leks, and the
associated nesting habitats in the area. Population-level effects of
this fire would not be reflected by any of the three population trend
analyses (Connelly et al., 2004; WAFWA 2008; Garton et al. in press)
simply because it occurred after the time period analyzed.
Projections of Future Populations
As described above, our analysis of habitat trends, and those
provided in the published literature show that population extirpation
and declines have, and are likely to continue to track habitat loss or
environmental changes (e.g., Walker et al., 2005, Aldridge et al. 2008;
Knick and Hanser in press; Wisdom et al. in press). Estimation of how
these trends may affect future population numbers and habitat carrying
capacity was conducted by Garton et al. (in press, entire). We realize
population viability analyses are based on assumptions that may or may
not be realistic given the species analyzed. Additionally, lek counts
are not the best data for use in these kinds of analyses as variability
in lek attendance, observer bias, and the unknown relationship between
males counted to actual population sizes limit unbiased estimation of
future population numbers (see also discussion under population sizes
above, and in Garton et al., in press, pp. 8, 66). At the request of
the Colorado Division of Wildlife, three individuals (Conroy 2009,
entire; Noon 2009, entire; Runge 2009, entire) reviewed Garton et al.
outside the established peer review process and noted similar
limitations of these data. We received these reviews and have reviewed
them in the context of all other data we received in preparation of
this finding. Their primary concern was about the applicability of
analyzing and presenting future population projections in the manner
done by Garton et al. in press, based on the limitations of the data,
the assumptions required, and uncertainty in the estimates of the model
parameters (see also discussion above).
Garton et al., (in press, pp. 6-8, 64-67) acknowledged these
concerns, as several of the reviewers pointed out, and their analyses
underwent peer review via the
[[Page 13959]]
normal scientific process prior to acceptance for publication.
Population viability analyses can provide useful information in
examining the potential future status of a species as long as the
assumptions of the model, and violations thereof, are clearly
identified and considered in the interpretation of the results.
Therefore, we present the analyses conducted by Garton et al. (in
press, entire) here in relation to our conclusion of how existing and
continued habitat fragmentation may impact the greater sage-grouse
within the foreseeable future. The projections reported by Garton et
al. (in press, entire; see discussion below) are generally consistent
with what we expect given the causes of sage-grouse declines and
extirpation documented in the literature (see above) and where those
threats occur in the species range, despite the concerns of the authors
and others about the limitations of lek data and prospective analysis.
We are unaware of any other prospective rangewide population viability
analyses for this species.
Garton et al. (in press, entire) projected population and habitat
carrying capacity trends (the modeled estimate where population growth
rate is 0) at 30 (2037) and 100 (2107) years into the future. Growth
rates were analogous to rates from 1987 to 2007, and quasi-extinction
thresholds (artificial thresholds below which the long-term persistence
and viability of a species is questionable due to stochastic variables,
such as small populations or genetic inbreeding) corresponded to
minimum counts of 20 and 200 males at leks (Garton et al. in press, p.
19). The thresholds were established to correspond to populations of 50
and 500 breeding birds, numbers generally accepted for adequate
effective population sizes to avoid negative genetic effects from
inbreeding (Garton et al. in press, p. 19). Therefore, population
projections that fell below 50 breeding adults (males and females) were
identified as being at short-term risk of extinction, and those that
fell below 500 breeding adults (males and females) were identified as
being at long-term risk for extinction. However, recent work by Bush
(2009, p. 106) suggests that a higher proportion of male sage-grouse
are breeding than previously identified. Therefore, Garton et al. (in
press, p. 20) state that their resulting projections are likely
underestimates of actual impacts as more birds are necessary than they
assumed for population productivity. Additionally, Traill et al. (2010,
p. 32) argue that a minimum effective population size must be 5,000
individuals to maintain evolutionary minimal viable populations of
wildlife (retention of sufficient genetic material to avoid effect of
inbreeding depression or deleterious mutations). We examined the
projected population trends for 30 years to minimize the risk of error
associated with the 100 year projections simply due to using lek data.
One assumption made by Garton et al. (in press, p. 19) is that
future population growth would be analogous to what occurred from 1987
to 2007. We anticipate adverse habitat impacts (see discussion of
foreseeable future below) and synergism between these impacts (e.g.
fire and invasive species expansion) to increase habitat loss;
therefore, Garton et al.'s (in press) likely over-estimate the
resulting future habitat carrying capacity and population numbers.
In all MZs, the analyses by Garton et al. (in press) predict that
populations will continue to decline. In MZ I, Garton et al. (in press,
p. 29) project a population decline of 59 percent between 2007 and 2037
if current population and habitat trends continue (Table 10). In the
Powder River Basin area, where significant gas development is
occurring, population trends were projected an almost 90 percent
decline by 2037 (Garton et al. in press, p. 26). This projection is
consistent with Walker et al. (2007, p. 2651) estimate that lek
persistence would decline to 5 percent in the Powder River Basin with
full field development over a similar time frame. Also, Johnson (in
press, p. 13) found that lek counts were reduced from 1997 to 2007 in
areas of oil and gas development, and our GIS analyses found that a
minimum of 70 percent of breeding habitats is affected by energy
development activities in this area (Service 2008b; see discussion
under Energy Development). Declines in the Powder River Basin within
the past 12 years of development have reached 79 percent (Emmerich
2009, pers. comm.). Populations in MZ I that do not experience the same
levels of energy development are not projected to decline as
significantly, with the exception of the Yellowstone watershed
population (Table 10). This population is projected to be extirpated
within 30 years (Garton et al. in press, p. 46). This area is highly
fragmented by agricultural and energy development, factors identified
by Aldridge et al. (2008, p. 991) and Wisdom et al. (in press, p. 23)
with sage-grouse extirpation. Wisdom et al. (in press, p. 23) also
predicted extirpation in this area due to the continuing loss of
sagebrush. Loss of the Yellowstone watershed population will result in
a gap in the species' range, isolating sage-grouse north of the
Missouri River from the rest of the species.
Table 10--Projected changes in carrying capacities of Management Zones and populations from 2007 to 2037.
Carrying capacities are reflected as the average number of males per lek, and were calculated by dividing
population projections for 2037 by the population estimate in 2007. Data from Garton et al. (in press, pp. 22-
63, 95-97).
----------------------------------------------------------------------------------------------------------------
Change in Carrying Capacity from
Management Zone Population 2007 to 2037 (%)
----------------------------------------------------------------------------------------------------------------
I (Great Plains) -59
----------------------------------------------------------------------------------------------------------------
Yellowstone watershed -100
----------------------------------------------------------------------------------------------------------------
Powder River -90
----------------------------------------------------------------------------------------------------------------
Northern Montana -11
----------------------------------------------------------------------------------------------------------------
Dakotas -62
----------------------------------------------------------------------------------------------------------------
..................................
----------------------------------------------------------------------------------------------------------------
II (Wyoming Basin) -66
----------------------------------------------------------------------------------------------------------------
[[Page 13960]]
Eagle - S. Routt extirpated
----------------------------------------------------------------------------------------------------------------
Jackson Hole --
----------------------------------------------------------------------------------------------------------------
Middle Park --
----------------------------------------------------------------------------------------------------------------
Wyoming Basin -64
----------------------------------------------------------------------------------------------------------------
..................................
----------------------------------------------------------------------------------------------------------------
III (Southern Great Basin) -55
----------------------------------------------------------------------------------------------------------------
Bi-State NV/CA -7
----------------------------------------------------------------------------------------------------------------
S. Mono Lake --
----------------------------------------------------------------------------------------------------------------
NE Interior UT +211
----------------------------------------------------------------------------------------------------------------
San Pete County UT --
----------------------------------------------------------------------------------------------------------------
S. central UT -36
----------------------------------------------------------------------------------------------------------------
Summit-Morgan UT -14
----------------------------------------------------------------------------------------------------------------
Toole-Juab UT -27
----------------------------------------------------------------------------------------------------------------
Southern Great Basin -61
----------------------------------------------------------------------------------------------------------------
..................................
----------------------------------------------------------------------------------------------------------------
IV (Snake River Plain) -55
----------------------------------------------------------------------------------------------------------------
Baker, OR No change
----------------------------------------------------------------------------------------------------------------
Bannack, MT -9
----------------------------------------------------------------------------------------------------------------
Red Rocks, MT -18
----------------------------------------------------------------------------------------------------------------
Wisdom, MT --
----------------------------------------------------------------------------------------------------------------
E. central ID --
----------------------------------------------------------------------------------------------------------------
Snake, Salmon, Beaverhead, ID -18
----------------------------------------------------------------------------------------------------------------
Northern Great Basin -73
----------------------------------------------------------------------------------------------------------------
..................................
----------------------------------------------------------------------------------------------------------------
V (Northern Great Basin) -74
----------------------------------------------------------------------------------------------------------------
Central OR -67
----------------------------------------------------------------------------------------------------------------
Klamath, OR --
----------------------------------------------------------------------------------------------------------------
NW Interior NV --
----------------------------------------------------------------------------------------------------------------
Western Great Basin -59
----------------------------------------------------------------------------------------------------------------
..................................
----------------------------------------------------------------------------------------------------------------
VI (Columbia Basin) -46
----------------------------------------------------------------------------------------------------------------
Moses Coulee -74
----------------------------------------------------------------------------------------------------------------
Yakima --
----------------------------------------------------------------------------------------------------------------
..................................
----------------------------------------------------------------------------------------------------------------
[[Page 13961]]
VII (Colorado Plateau)* --
----------------------------------------------------------------------------------------------------------------
-- Data insufficient to model
* Although the model projects population increases, habitat is limited in the area, likely limiting actual
population growth.
Garton et al. (in press, p. 36) projected populations will decline
in MZ II by 66 percent between 2007 and 2037 if current population
trends and habitat activities continue (Table 10). The Wyoming Basin
area, where significant oil, gas and renewable energy development is
occurring, is projected to decline by 64 percent (Garton et al. in
press, p. 34). Population persistence for the Eagle-South Routt
population, an area also experiencing significant energy development
activities, could not be estimated due to data sampling concerns.
However, the population is unlikely to persist for 20 years (Braun, as
cited in Garton et al. in press, p 30), where 100 percent of the
breeding habitat is affected by energy development (Service 2008b).
Johnson (in press, p. 13) found that declines in lek attendance was
strongly, negatively associated with the presence of wells in these
areas once the total number of wells in this MZ exceeded 250. Wells in
both of these populations currently exceed that threshold. Therefore,
the results of Garton et al.'s (in press) analyses are not unexpected.
Garton et al. (in press, p. 46) projected populations in MZ III
will decline by 53 percent between 2007 and 2037 if current population
trends and habitat activities continue (Table 10). Most populations in
this area are already isolated by topographic features and experience
high native conifer incursions. Bromus tectorum also is of significant
concern in the Southern Great Basin population. Large losses of
sagebrush in this MZ have resulted from B. tectorum incursion and the
resulting altered fire cycle (Johnson in press, p. 23). Fire within 54
km (33.5 mi) of a lek was identified by Knick and Hanser (in press, p.
29) as one of the most important factors negatively affecting sage-
grouse persistence on the landscape. Assuming the current rate of
habitat loss continues in this MZ, carrying capacity is projected to
decline by 45 percent by 2037 (Garton et al. in press, p. 46).
In MZ IV, Garton et al. (in press, p. 53) populations are projected
to decline by 55 percent between 2007 and 2037 if current population
trends and habitat activities continue (Table 10). The Northern Great
Basin population is projected to have the greatest drop in carrying
capacity, and is the area currently most affected by reduced fire
cycles as a result of Bromus tectorum incursions. As discussed above,
fire within 54 km (33.5 mi) of a lek was identified by as one of the
most important factors negatively affecting sage-grouse persistence on
the landscape (Knick and Hanser in press, p. 29). The associated
incursion of B. tectorum has resulted in large losses of habitat in
this MZ (Johnson in press, p. 23). Carrying capacities in other
populations in this MZ are not projected to decline as much, but these
populations do not have significant fire and B. tectorum incursions.
In MZ V, Garton et al. (in press, p. 58) projected populations will
decline by 74 percent between 2007 and 2037 if current population
trends and habitat activities continue (Table 10). Nearly all
populations within this MZ are affected by reduced fire frequencies and
Bromus tectorum incursions (see discussion above). In MZ VI, Garton et
al. (in press, p. 62) projected populations will decline by 46 percent
between 2007 and 2037 if current population trends and habitat
activities continue (Table 10). The two populations in this MZ are
already isolated from the rest of the range, and actively managed by
the State of Washington to maintain birds (e.g., translocations, active
habitat enhancement). In addition to impacts from agricultural
activities and human development (Johnson in press, p. 27), these
populations are affected by the loss of CRP lands and military
activities, neither of which were quantified by Garton et al. (in
press, entire). Therefore, the projections provided in the population
viability analysis are likely underestimated.
Carrying capacity projections could not be estimated for MZ VII due
to insufficient data. Energy development activities occur within most
populations in this area, and Johnson (in press, p. 13) reported that
lek attendance was lower around producing wells in this MZ. We believe
that based on habitat impacts, if birds are retained in this area, the
populations will be reduced in size and further isolated.
The projections from Garton et al. (in press, entire), which are
consistent with results reported by Wisdom et al. (in press, entire),
our own analyses, and others examining the effects of habitat loss and
degradation on population trends, reflect that by 2037 sage-grouse
populations and connectivity between them will be further reduced
across the species range. This is consistent with other literature that
has documented patterns of decline and extirpation as a result of the
ongoing habitat losses and fragmentation (for example, see Johnson in
press, Knick et al. in press and Wisdom et al. in press). We are
cautious in using a single projection for determining future population
status based on the limitation of lek data and the lack of any other
comparable rangewide population viability analyses. However, Garton et
al.'s (in press, entire) results are consistent with the habitat loss
and fragmentation analyses conducted by the Service and many other
authors, as noted in the individual MZ discussions above.
The population and carrying capacity projections by Garton et al.
(in press, pp. 22-64 ) are generally consistent with what we would
expect given the causes of sage-grouse declines and extirpation
documented in the literature (see above) and where those threats occur
in the species range. Therefore, despite the concerns of the authors
and other about the limitations of lek data and prospective analysis,
the results presented by Garton et al. (in press, entire) are
consistent with our analyses of habitat impacts based on the review of
the best available scientific information.
Foreseeable Future of Habitat Threats
We examined the persistence of each of these habitat threats on the
landscape to help inform a determination of foreseeable future. Habitat
conversion and fragmentation resulting from agricultural activities and
urbanization will continue indefinitely. Human
[[Page 13962]]
populations are increasing in the western United States and we have no
data indicating this trend will be reversed. Increased fire frequency
as facilitated by the expanding distribution of invasive plant species
will continue indefinitely unless an effective means for controlling
the invasives is found. In the last approximately 100 years, no broad
scale Bromus tectorum eradication method has been developed. Therefore,
given the history of invasive plants on the landscape, our continued
inability to control such species, and the expansive infestation of
invasive plants across the species' range currently, we anticipate they
and associated fires will be on the landscape for the next 100 years or
longer.
Continued exploration and development of traditional and
nonconventional fossil fuel sources in the eastern portion of the
greater sage-grouse range will continue to increase over the next 20
years (EIA 2009b, p. 109). Based on existing National Environmental
Policy Act (NEPA) documents for major oil and gas developments,
production within existing developments will continue for a minimum of
20 years, with subsequent restoration (if possible) requiring from 30
to 50 additional years. Renewable energy development is estimated to
reach maximum development by 2030. However, since most renewable energy
facilities are permanent landscape features, unlike oil, gas and coal,
direct and functional habitat loss from the development footprint will
be permanent. Based on this information, we estimate the foreseeable
future of energy development at a minimum of 50 years, and perhaps much
longer for nonrenewable sources.
Grazing (both domestic and wild horse and burro) is unlikely to be
removed from sagebrush ecosystems. Therefore, it is difficult to
estimate a foreseeable future for livestock grazing. However, as of
2007, there were 7,118,989 permitted AUMs in sage-grouse habitat.
Although there have been recent reductions in the number of AUMs (3.4
percent since 2005), we have no information suggesting that livestock
grazing will be significantly reduced, or removed, from sage-grouse
habitats. Therefore, while we cannot provide an exact estimate of the
foreseeable future for grazing, we expect it to be a persistent use of
the sage-grouse landscape for several decades.
Summary of Factor A
As identified above in our Factor A analysis, habitat conversion
for agriculture, urbanization, infrastructure (e.g., roads, powerlines,
fences); fire, invasive plants, pinyon-juniper woodland encroachment,
grazing, energy development, and climate change are all contributing,
individually and collectively, to the present and threatened
destruction, modification, and curtailment of the habitat and range of
the greater sage-grouse. The impacts are compounded by the fragmented
nature of this habitat loss, as fragmentation results in functional
loss of habitat for greater sage-grouse even when otherwise suitable
habitat is still present.
Fragmentation of sagebrush habitats is a key cause, if not the
primary cause, of the decline of sage-grouse populations. Fragmentation
can make otherwise suitable habitat either too small or isolated to be
of use to greater sage-grouse (i.e., functional habitat destruction),
or the abundance of sage-grouse that can be supported in an area is
diminished. Fire, invasive plants, energy development, various types of
infrastructure, and agricultural conversion have resulted in habitat
fragmentation and additional fragmentation is expected to continue for
the foreseeable future in some areas.
In our evaluation of Factor A, we found that although many of the
habitat impacts we analyzed (e.g, fire, urbanization, invasive species)
are present throughout the range, they are not at a level that is
causing a threat to greater sage-grouse everywhere within its range.
Some threats are of high intensity in some areas but are low or
nonexistent in other areas. Fire and invasive plants, and the
interaction between them, is more pervasive in the western part of the
range than in the eastern. Oil and gas development is having a high
impact on habitat in many areas in the eastern part of the range, but a
low impact further to the west. The impact of pinyon-juniper
encroachment generally is greater in western areas of the range, but is
of less concern in more eastern areas such as Wyoming and Montana.
Agricultural development is high in the Columbia Basin, Snake River
Plain, and eastern Montana, but low elsewhere. Infrastructure of
various types is present throughout the most of range of the greater
sage-grouse, as is livestock grazing, but the degree of impact varies
depending on grazing management practices and local ecological
conditions. The degree of urbanization and exurban development varies
across the range, with some areas having relatively low impact to
habitat.
While sage-grouse habitat has been lost or altered in many portions
of the species' range, habitat still remains to support the species in
many areas of its range (Connelly et al. in press c, p. 23), such as
higher elevation sagebrush, and areas with a low human footprint
(activities sustaining human development) such as the Northern and
Southern Great Basin (Leu and Hanser in press, p. 14), indicating that
the threat of destruction, modification or curtailment of the greater
sage-grouse is moderate in these areas. In addition, two strongholds of
contiguous sagebrush habitat (the southwest Wyoming Basin and the Great
Basin area straddling the States of Oregon, Nevada, and Idaho) contain
the highest densities of males in the range of the species (Wisdom et
al. in press, pp. 24-25; Knick and Hanser in press, p. 17). We believe
that the ability of these strongholds to maintain high densities to
date in the presence of several threats indicates that there are
sufficient habitats currently to support the greater sage-grouse in
these areas, but not throughout its entire range unless these threats
are ameliorated.
As stated above, the impacts to habitat are not uniform across the
range; some areas have experienced less habitat loss than others, and
some areas are at relatively lower risk than others for future habitat
destruction or modification. Nevertheless, the impacts are substantial
in many areas and will continue or even increase in the future across
much of the range of the species. With continued habitat destruction
and modification, resulting in fragmentation and diminished
connectivity, greater sage-grouse populations will likely decline in
size and become more isolated, making them more vulnerable to further
reduction over time and increasing the risk of extinction.
We have evaluated the best scientific and commercial information
available regarding the present or threatened destruction,
modification, or curtailment of the greater sage-grouse's habitat or
range. Based on the current and ongoing habitat issues identified here,
their synergistic effects, and their likely continuation in the future,
we conclude that this threat is significant such that it provides a
basis for determining that the species warrants listing under the Act
as a threatened or endangered species.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Commercial Hunting
The greater sage-grouse was heavily exploited by commercial hunting
in the late 1800s and early 1900s (Patterson 1952, pp. 30-32;
Autenrieth 1981, pp. 3-11). Hornaday (1916, pp. 179-221) and others
alerted the public to the risk of
[[Page 13963]]
extinction of the species as a result of this overharvest. The impacts
of hunting on greater sage-grouse during those historical decades may
have been exacerbated by impacts from human expansion into sagebrush-
steppe habitats (Girard 1937, p. 1). In response, many States closed
sage-grouse hunting seasons by the 1930s (Patterson 1952, pp.30-33;
Autenrieth 1981, p. 10). Sage-grouse have not been commercially
harvested for many decades; therefore, commercial hunting does not
affect the greater sage-grouse.
Recreational Hunting
With the increase of sage-grouse populations by the 1950s, limited
recreational hunting seasons were allowed in most of the species' range
(Patterson 1952, p. 242; Autenrieth 1981, p.11). Currently, greater
sage-grouse are legally sport-hunted in 10 of 11 States where they
occur (Connelly et al. 2004, p. 6-3). The hunting season for sage-
grouse in Washington was closed in 1988, and the species was added to
the State's list of threatened species in 1998 (Stinson et al. 2004, p.
1). In Canada, sage-grouse are designated as an endangered species, and
hunting is not permitted (Connelly et al. 2004, p. 6-3).
[GRAPHIC] [TIFF OMITTED] TP23MR10.002
Harvest levels have varied considerably since the 1950s, and in
recent years have been much lower than in past decades (Figure 3)
(Service 2009, unpublished data). From 1960 to 1980, the majority of
sage-grouse hunting mortality occurred in Wyoming, Idaho, and Montana,
accounting for at least 75 to 85 percent of the annual harvest (Service
2009, unpublished data). In the 1960s harvest exceeded 120,000
individuals annually for 7 out of 10 years. Harvest levels reached a
maximum in the 1970s, being above 200,000 individuals in 9 of 10 years
with the total estimate at 2,322,581 birds harvested for the decade.
During the 1980s, harvest exceeded 130,000 individuals in 9 of 10 years
(Service 2009, unpublished data). The harvest was above 100,000
annually during the early 1990s but in 1994 dropped below 100,000 for
the first time in decades. From 2000 to 2007, annual harvest has
averaged approximately 31,000 birds (Service 2009, unpublished data).
Sustainable harvest is determined based on the concept of
compensatory and additive mortality (Connelly 2005, p. 7). The
compensatory mortality hypothesis asserts that if sage-grouse produce
more offspring than can survive to sexual maturity, individuals lost to
hunting represent losses that would have occurred otherwise from some
other source (e.g., starvation, predation, disease). Hunting mortality
is termed additive if it exceeds natural mortality and ultimately
results in a decline of the breeding population. The validity of
compensatory mortality in upland gamebirds has not been rigorously
tested, and as we stated above, annual
[[Page 13964]]
sage-grouse productivity is relatively low compared to other grouse
species. Autenrieth (1981, p. 77) suggested sage-grouse could sustain
harvest rates of up to 30 percent annually. Braun (1987, p. 139)
suggested a rate of 20 to 25 percent was sustainable. State wildlife
agencies currently attempt to keep harvest levels below 5 to 10 percent
of the population, based on a recommendation taken from Connelly et al.
(2000a, p. 976). However, it is unclear from Connelly et al. (2000a)
what this recommendation is based on, and similar to previous suggested
harvest rates, it has not been experimentally tested with regard to its
impacts on sage-grouse populations.
The validity of the idea that hunting is a form of compensatory
mortality for upland game birds has been questioned in recent years
(Reese and Connelly, in press, p. 6). Connelly et al. 2005 (pp. 660,
663) cite many studies suggesting that hunting of upland game,
including the greater sage-grouse, is often not compensatory. Other
studies have sought to determine whether hunting mortality in sage-
grouse is compensatory or additive (Crawford 1982; Crawford and Lutz
1985; Braun 1987; Zunino 1987; Johnson and Braun 1999; Connelly et al.
2003; Sedinger et al. in press; Sedinger et al. unpublished data).
Results of those studies have been contradictory. For example, Braun
(1987, p. 139) found that harvest levels of 7 to 11 percent had no
effect on subsequent spring breeding populations based on lek counts in
North Park, Colorado. Johnson and Braun (1999, p. 83) determined that
overwinter mortality correlated with harvest intensity in North Park,
Colorado, and hypothesized that hunting mortalities may be additive.
Numerous contradictions are likely due to differing methods, lack
of experimental data, and differing effects of harvest due to a
relationship between harvest and habitat quality. For example, Connelly
et al. (2003, pp. 256-257) evaluated data for monitored lek routes in
areas experiencing different levels of harvest (no harvest, 1-bird
season, 2-bird season) in Idaho and found that populations with no
hunting season had faster rates of population increase than populations
with a light to modest harvest. The effect was particularly pronounced
in xeric habitats near human populations, which suggests that the
impact of hunting on sage-grouse to some extent depends on habitat
quality. Gibson (1998, p. 15) found that hunting mortality had negative
impacts on the population dynamics of an isolated population of sage-
grouse in Long Valley, California, but appeared to have no effect on
sage-grouse in Bodie Hills, California, a nearby population that is
contiguous with adjacent occupied areas of Nevada. Data indicated that
hunting suppressed the population size of the isolated Long Valley
population well below the apparent carrying capacity (Gibson 1998, p.
15; Gardner 2008, pers. comm.).
Sage-grouse hunting is regulated by State wildlife agencies.
Hunting seasons are reviewed annually, and States change harvest
management based on estimates for spring production and population size
(e.g., Bohne 2003, pp.1-10). However, harvest affects fall populations
of sage-grouse, and currently there is no reliable method for obtaining
estimates of fall population size (Connelly et al. 2004, p. 9-6).
Instead, lek counts conducted in the spring are used as a surrogate for
fall population size. However, fall populations are already reduced
from spring estimates as some natural mortality inevitably has occurred
in the interim (Kokko 2001, p. 164). The discrepancy between spring and
fall population size estimates plays a role in determining whether
harvest will be within the recommended level of less than 5-10 percent
of the fall population. For example, hen mortality in Montana increased
from the typical level of 1 to 5 percent to 16 percent during July/
August in a year (2003) with WNv mortality (Moynahan 2006, p.1535).
During the summer of 2006 and 2007 in South Dakota, mortality from WNv
was estimated to be between 21 and 63 percent of the population (Kaczor
2008, p.72). Despite the increased mortalities due to WNv, hunting
regulations in both States remained similar to previous years.
Female survivorship is a key element of population productivity.
Harvest might affect female and male grouse differently. Connelly et
al. (2000b, p.228-229) found that in Idaho 42 percent of all documented
female mortality was attributable to hunting while for males the number
was 15 percent. Patterson (1952, p. 245) found females accounted for 60
percent (1950) and 63 percent (1951) of total hunting mortalities.
Because sage-grouse are relatively long-lived, have moderate
reproductive rates, and are polygynous, their populations are likely to
be especially sensitive to adult female survival (Schroeder 1999, p.2,
13; Saether and Bakke 2000, p. 652; Connelly 2005, p.9). Yearling sage-
grouse hens have less reproductive potential than adults (Dalke et al.
1963, p. 839; Moynahan 2006, p. 1537). Adult females have higher nest
initiation rates, higher nest success, and higher chick survival rates
than yearling females (Connelly et al., in press a, pp. 15, 20, 48).
High adult female mortality has the potential to result in negative lag
effects as future populations become overrepresented by yearling
females (Moynahan 2006, p. 1537).
All States with hunting seasons have changed limits and season
dates to more evenly distribute hunting mortality across the entire
population structure of greater sage-grouse, harvesting birds after
females have left their broods (Bohne 2003, p. 5). Females and broods
congregate in mesic areas late in the summer potentially making them
more vulnerable to hunting (Connelly et al. 2000b, p. 230). However,
despite increasingly later hunting seasons, hens in Wyoming continue to
comprise the majority of the harvest in all years (WGFD 2004a, p. 4;
2006, p. 7). From 1996 to 2008, on average 63 percent of adult hunting
mortalities in Nevada were females (range 58 percent to 73 percent)
(NDOW, 2009, unpublished data). In 2008 in Oregon, adult females
accounted for 70 percent of the adults harvested (ODFW 2009). These
results could indicate that females are more susceptible to hunting
mortality, or it could be a reflection of a female skewed sex ratio in
adult birds. Male sage-grouse typically have lower survival rates than
females, and the varying degrees of female skewed sex ratios recorded
for sage-grouse are thought to be as a result of this differential
survival (Swenson 1986, p. 16; CO Conservation Plan, p. 54). The
potential for negative effects on populations by harvesting
reproductive females has long been recognized by upland game managers
(e.g., hunting of female ring-necked pheasants, (Phasianus colchicus),
is prohibited in most States).
Harvest management levels that are based on the concept of
compensatory mortality assume that overwinter mortality is high, which
is not true for sage-grouse (winter mortality rates approximately 2
percent, Connelly et al. 2000b, p. 229). Additionally, due to WNv,
sage-grouse population dynamics may be increasingly affected by
mortality that is density independent (i.e., mortality that is
independent of population size). Further, there is growing concern
regarding wide-spread habitat degradation and fragmentation from
various sources, such as development, fire, and the spread of noxious
weeds, resulting in density independent mortality which increases the
probability that harvest mortality will be additive.
State management agencies have become increasingly responsive to
these concerns. All of the States where hunting greater sage-grouse is
legal,
[[Page 13965]]
except Montana, now manage harvests on a regional scale rather than
applying State-wide limits. Bag limits and season lengths are
relatively conservative compared to prior decades (Connelly 2005, p. 9;
Gardner 2008, pers. comm.). Emergency closures have been used for some
declining populations. For example, North Dakota closed the 2008 and
2009 hunting seasons following record low lek attendance likely due to
WNv (Robinson 2009, pers. comm.). Hunting on the Duck Valley Indian
Reservation (Idaho/Nevada) has been closed since 2006 due to WNv (Dick
2009, pers. comm.; Gossett 2008, pers. comm.). Hunting in Owyhee
County, Idaho was closed in 2006 and again in 2008 and 2009 as a result
of WNv (Dick 2008, pers. comm.; IDFG 2009).
All ten States that allow bow and gun hunting of sage-grouse also
allow falconers to hunt sage-grouse. Falconry seasons are typically
longer (60 to 214 days), and in some cases have larger bag limits than
bow/gun seasons. However, due to the low numbers of falconers and their
dispersed activities, the resulting harvest is thought to be negligible
(Apa 2008, pers. comm.; Northrup 2008, pers. comm.; Hemker 2008, pers.
comm.; Olsen 2008, pers. comm.; Kanta 2008, pers. comm.). Wyoming is
one of the few States that collects falconry harvest data and reported
a take of 180 sage-grouse by falconers in the 2006-2007 season (WGFD
2007, unpublished data). In Oregon, the take is probably less than five
birds per year (Budeau 2008, pers. comm.). In Idaho the 2005 estimated
Statewide falconry harvest was 77 birds, and that number has likely
remained relatively constant (Hemker 2008, pers. comm.). We are not
aware of any studies that have examined falconry take of greater sage-
grouse in relation to population trends, but the amount of greater
sage-grouse mortality associated with falcon sport hunting appears to
be negligible.
We surveyed the State fish and wildlife agencies within the range
of greater sage-grouse to determine what information they had on
illegal harvest (poaching) of the species. Nevada and Utah indicated
they were aware of citations being issued for sage-grouse poaching, but
that it was rare (Espinosa 2008, pers. comm.; Olsen 2008, pers. comm.).
Sage-grouse wings are infrequently discovered in wing-barrel collection
sites during forest grouse hunts in Washington, but such take is
considered a result of hunter misidentification rather than deliberate
poaching (Schroeder 2008, pers. comm.). None of the remaining States
had any quantitative data on the level of poaching. Based on these
results, illegal harvest of greater sage-grouse poaching appears to
occur at low levels. We are not aware of any studies or other data that
demonstrate that poaching has contributed to sage-grouse population
declines.
Recreational Use
Greater sage-grouse are subject to a variety of non-consumptive
recreational uses such as bird watching or tour groups visiting leks,
general wildlife viewing, and photography. Daily human disturbances on
sage-grouse leks could cause a reduction in mating and some reduction
in total production (Call and Maser 1985, p. 19). Overall, a relatively
small number of leks in each State receive regular viewing use by
humans during the strutting season and most States report no known
impacts from this use (Apa 2008, pers. comm.; Christiansen 2008, pers.
comm.; Gardner 2008, pers. comm.; Northrup 2008, pers. comm.). Only
Colorado has collected data regarding the effects of non-consumptive
use. Their analyses suggest that controlled lek visitation has not
impacted greater sage-grouse (Apa 2008, pers. comm.). However, Oregon
reported anecdotal evidence of negative impacts of unregulated viewing
to individual leks near urban areas that are subject to frequent
disturbance from visitors (Hagen 2008, pers. comm.).
To reduce any potential impact of lek viewing on sage-grouse,
several States have implemented measures to protect most leks while
allowing recreational viewing to continue. The Wyoming Game and Fish
Department (WGFD) provides the public with directions to 16 leks and
guidelines to minimize viewing disturbance. Leks included in the
brochure are close to roads and already subject to some level of
disturbance (Christiansen 2008, pers. comm.); presumably, focusing
attention on these areas reduces pressure on relatively undisturbed
leks. Colorado and Montana have some sites with viewing trailers for
the public for the same reasons (Apa 2008, pers. comm.; Northrup 2008,
pers. comm.). We were not able to locate any studies documenting how
lek viewing, or other forms of non-consumptive recreational uses, of
sage-grouse are related to sage-grouse population trends. Given the
relatively small number of leks visited, we have no reason to believe
that this type of recreational activity is having a negative impact on
local populations or contributing to declining population trends.
Religious Use
Some Native American tribes harvest greater sage-grouse as part of
their religious or ceremonial practices as well as for subsistence.
Native American hunting occurs on the Wind River Indian Reservation
(Wyoming), with about 20 males per year taken off of leks in the spring
plus an average fall harvest of approximately 40 birds (Hnilicka 2008,
pers. comm.). The Shoshone-Bannock Tribe (Idaho) occasionally takes
small numbers of birds in the spring, but no harvest figures have been
reported for 2007 and 2008 (Christopherson 2008, pers. comm.). The
Shoshone-Paiute Tribe of the Duck Valley Indian Reservation (Idaho and
Nevada) suspended hunting in 2006 to 2009 due to significant population
declines resulting from a WNv outbreak in the area (Dick 2009, pers.
comm.; Gossett 2008, pers. comm.). Prior to 2006, the sage-grouse
hunting season on the Duck Valley Indian Reservation ran from July 1 to
November 30 with no bag or possession limits. Preliminary estimates
indicate that the harvest may have been as high as 25 percent of the
population (Gossett 2008, pers. comm.). Despite the hunting ban,
populations have not recovered on the reservation (Dick 2009, pers.
comm.; Gossett 2008, pers. comm.). No harvest by Native Americans for
subsistence or religious and ceremonial purposes occurs in South
Dakota, North Dakota, Colorado, Washington, or Oregon (Apa 2008, pers.
comm.; Hagen 2008, pers. comm.; Kanta 2008, pers. comm.; Robinson 2008,
pers. comm.; Schroeder 2008, pers. comm.).
Scientific and Educational Use
Greater sage-grouse are the subject of many scientific research
studies. We are aware of some 51 studies ongoing or completed during
2005 and 2008. Of the 11 western States where sage-grouse currently
occur, all reported some type of field studies that included the
capture, handling, and subsequent banding, or banding and radio-tagging
of sage-grouse. In 2005, the overall mortality rate due to the capture,
handling, and/or radio-tagging process was calculated at approximately
2.7 percent of the birds captured (68 mortalities of 2,491 captured). A
survey of State agencies, BLM, consulting companies, and graduate
students involved in sage-grouse research indicates that there has been
little change in direct handling mortality since then. We are not aware
of any studies that document that this level of taking has affected any
sage-grouse population trends.
Greater sage-grouse have been translocated in several States and
the Province of British Columbia (Reese and Connelly 1997, p. 235).
Reese and Connelly (1997, pp. 235-238)
[[Page 13966]]
documented the translocation of over 7,200 birds between 1933 and 1990.
Only 5 percent of the translocation efforts documented by Reese and
Connelly (1997, p. 240) were considered to be successful in producing
sustained, resident populations at the translocation sites. From 2003
to 2005, 137 adult female sage-grouse were translocated to Strawberry
Valley, Utah and had a 60 percent annual survival rate (Baxter et al.
2006, p. 182). Since 2004, Oregon and Nevada have supplied the State of
Washington with close to 100 greater sage-grouse to increase the
genetic diversity of the geographically isolated Columbia Basin
populations and to reestablish a historical population. One bird has
died during transit and as expected natural mortality for translocated
birds has been higher than resident populations (Schroeder 2008, pers.
comm.). Given the low numbers of birds that have been used for
translocation spread over many decades, it is unlikely that the
removals from source populations have contributed to greater sage-
grouse declines, while the limited success of translocations also has
likely had nominal impact on rangewide population trends. We did not
find any information regarding the direct use of greater sage-grouse
for educational purposes.
Summary of Factor B
Greater sage-grouse are not used for any commercial purpose. In
Canada, hunting of sage-grouse is prohibited in Alberta and
Saskatchewan. In the United States, sage-grouse hunting is regulated by
State wildlife agencies and hunting regulations are reevaluated yearly.
We have no information that suggests any change will occur in the
current situation, in which hunting greater sage-grouse is prohibited
in Washington and allowed elsewhere in the range of the species in the
U.S. under State regulations, which provide a basis for adjustments in
annual harvest and emergency closures of hunting seasons. We have no
evidence suggesting that gun and bow sport hunting has been a primary
cause of range-wide declines of the greater sage-grouse in the past, or
that it currently is at level that poses a significant threat to the
species. However, although harvest as a singular factor does not appear
to threaten the species throughout its range, negative impacts on local
populations have been demonstrated and there remains a large amount of
uncertainty regarding harvest impacts because of a lack of experimental
evidence and conflicting studies. Significant habitat loss and
fragmentation have occurred during the past several decades, and there
is evidence that the sustainability of harvest levels depends to a
large extent upon the quality of habitat and the health of the
population. However, recognition that habitat loss is a limiting factor
is not conclusive evidence that hunting has played no role in
population declines or that reducing or eliminating harvest will not
have an effect on population stability or recovery.
Take from poaching (illegal hunting) appears to occur at low levels
in localized areas, and there is no evidence that it contributes to
population declines. The information on non-consumptive recreational
activities is limited to lek viewing, the extent of such activity is
small, and there is no indication that it has a negative impact that
contributes to population declines. Harvest by Native American tribes,
and mortality that results from handling greater sage-grouse for
scientific purposes appears to occur at low levels in localized areas
and thus we do not consider these to be a significant threat at either
the rangewide or local population levels. We know of no utilization for
educational purposes. We have no reason to believe any of the above
activities will increase in the future.
We do not believe data support overuse of sage-grouse as a singular
factor in rangewide population declines. We note, however, that in
light of present and threatened habitat loss (Factor A) and other
considerations (e.g. West Nile virus outbreaks in local populations),
continued close attention will be needed by States and tribes to
carefully manage hunting mortality, including adjusting seasons and
allowable harvest levels, and imposing emergency closures if needed.
In sum, we find that this threat is not significant to the species
such that it causes the species to warrant listing under the Act.
Factor C: Disease and Predation
Disease
Greater sage-grouse are hosts for a variety parasites and diseases,
including macroparasitic arthropods, helminths and microparasites
(protozoa, bacteria, viruses and fungi) (Thorne et al. 1982, p. 338;
Connelly et al. 2004, pp. 10-4 to 10-7; Christiansen and Tate, in
press, p. 2). However, there have been few systematic surveys for
parasites or infectious diseases of greater sage-grouse; therefore,
whether they have a role in population declines is unknown (Connelly et
al. 2004, p. 10-3; Christiansen and Tate, in press, p. 3). Early
studies have suggested that sage-grouse populations are adversely
affected by parasitic infections (Batterson and Morse 1948, p. 22).
Parasites also have been implicated in sage-grouse mate selection, with
potentially subsequent effects on the genetic diversity of this species
(Boyce 1990, p. 263; Deibert 1995, p. 38). However, Connelly et al.
(2004, p. 10-6) note that, while these relationships may be important
to the long-term ecology of greater sage-grouse, they have not been
shown to be significant to the immediate population status. Connelly et
al. (2004, p. 10-3) have suggested that diseases and parasites may
limit isolated sage-grouse populations, but that the effects of
emerging diseases require additional study (see also Christiansen and
Tate, in press, pp. 22-23).
Internal parasites which have been documented in the greater sage-
grouse include the protozoans Sarcosystis spp. and Tritrichomonas
simoni, blood parasites (including avian malaria (Plasmodium spp.),
Leucocytozoon spp., Haemoproteus spp., and Trypanosoma avium, tapeworms
(Raillietina centrocerci and R. cesticillus), gizzard worms (Habronema
spp. and Acuaria spp.), cecal worms (Heterakis gallinarum), and filarid
nematodes (Ornithofilaria tuvensis) (Honess 1955, pp.1-2; Hepworth
1962, p. 6: Thorne et al. 1982, p. 338; Connelly et al. 2004, pp. 10-4
to 10-6; Petersen 2004, p. 50; Christiansen and Tate, in press, pp. 9-
13). None of these parasites have been known to cause mortality in the
greater sage-grouse (Christiansen and Tate, in press, p. 8-13). Sub-
lethal effects of these parasitic infections on sage-grouse have never
been studied.
Greater sage-grouse host many external parasites, including lice,
ticks, and dipterans (midges, flies, mosquitoes, and keds) (Connelly et
al. 2004, pp. 10-6 to 10-7). Most ectoparasites do not produce disease,
but can serve as disease vectors or cause mechanical injury and
irritation (Thorne et al. 1982, p. 231). Ectoparasites can be
detrimental to their hosts, particularly when the bird is stressed by
inadequate habitat or nutritional conditions (Petersen 2004, p. 39).
Some studies have suggested that lice infestations can affect sage-
grouse mate selection (Boyce 1990, p. 266; Spurrier et al. 1991, p. 12;
Deibert 1995, p. 37), but population impacts are not known (Connelly et
al. 2004, p. 10-6).
Only a few parasitic infections in greater sage-grouse have been
documented to result in fatalities, including the protozoan, Eimeria
spp. (coccidiosis) (Connelly et al. 2004, p.
[[Page 13967]]
10-4), and possibly ixodid ticks (Haemaphysalis cordeilishas).
Mortality is not 100 percent with coccidiosis, and young birds that
survive an initial infection typically do not succumb to subsequent
infections (Thorne et al. 1982, p. 112). Infections also tend to be
localized to specific geographic areas. Most cases of coccidiosis in
greater sage-grouse have been found where large numbers of birds
congregated, resulting in soil and water contamination by fecal
material (Scott 1940, p. 45; Honess and Post 1968, p. 20; Connelly et
al. 2004, p. 10-4; Christiansen and Tate, in press, p. 3). While the
role of this parasite in population regulation is unknown, Petersen
(2004, p. 47) hypothesized that coccidiosis could be limiting for local
populations, as this parasite causes decreased growth and resulted in
significant mortality in young birds, thereby potentially limiting
recruitment. However, no cases of sage-grouse mortality resulting from
coccidiosis have been documented since the early 1960s (Connelly et al.
2004, p. 10-4), with the exception of two yearlings being held in
captivity (Cornish 2009a, pers. comm.). One hypothesis for the apparent
decline in occurrences of coccidiosis is the reduced density of sage-
grouse, limiting the spread of the disease (Christiansen and Tate, in
press, p. 14).
The only mortalities associated with ixodid ticks were found in
association with a tularemia (Francisella tularenis) outbreak in
Montana (Parker et al. 1932, p. 480; Christiansen and Tate, in press,
p. 7). The sage-grouse mortality was likely from the pathological
effects of the abnormally high number of feeding ticks found on the
birds, as well as tularemia infection itself (Christiansen and Tate, in
press, p.15). No other reports of tularemia have been recorded in
greater sage-grouse (Christiansen and Tate, in press, p. 15).
Greater sage-grouse also are subject to a variety of bacterial,
fungal, and viral pathogens. The bacteria Salmonella spp. has caused
mortality in the greater sage-grouse and was apparently contracted
through of exposure to contaminated water supplies around livestock
stock tanks (Connelly et al. 2004, p. 10-7). However, it is unlikely
that diseases associated with Salmonella spp. pose a significant risk
to sage-grouse unless environmental conditions concentrate birds,
resulting in contamination of limited water supplies by accumulated
fecal material (Christiansen and Tate, in press, p. 15). A tentative
documentation of Mycoplasma spp. in sage-grouse is known from Colorado
(Hausleitner 2003, p. 147), but we found no other information to
suggest this bacterium is either fatal or widespread. Other bacteria
found in sage-grouse include avian tuberculosis (Mycobacterium avium),
and avian cholera (Pasteurella multocida). These bacteria have never
been identified as a cause of mortality in greater sage-grouse and the
risk of exposure and hence, population effects, is low (Connelly et al.
2004, p. 10-7 to 10-8).
Sage-grouse afflicted with coccidiosis in Wyoming also were
positive for Escherichia coli (Honess and Post 1968, p. 17). This
bacterium is not believed to be a threat to wild populations of greater
sage-grouse (Christiansen and Tate, in press, p. 15), as it has only
been shown to cause acute mortality in captive birds kept in unsanitary
conditions (Friend 1999, p. 125). One death from Clostridium
perfringens has been recorded in a free-ranging adult male sage-grouse
in Oregon (Hagen and Bildfell 2007, p. 545). Friend (1999, p. 123)
mentions that outbreaks of Clostridum have been reported in greater
sage-grouse, but the only information we located were two deaths
reported from northeastern Wyoming (Cornish 2009a, pers. comm.).
Christiansen and Tate (in press, p. 14) caution that given the
persistence of this bacterium's spores in the soil, the resulting
necrotic enteritis, especially when coupled with coccidiosis, may be a
concern in small isolated populations.
One case of aspergillosis, a fungal disease, has been documented in
sage-grouse, but there is no evidence to suggest this fungus plays a
role in limiting greater sage-grouse populations (Connelly et al. 2004,
p. 10-8; Petersen 2004, p. 45). Sage-grouse habitats are generally
incompatible with the ecology of this disease due to their arid
conditions.
Viruses could cause serious diseases in grouse species and
potentially influence population dynamics (Petersen 2004, p. 46).
However, prior to 2002, only avian infectious bronchitis (caused by a
coronavirus) had been identified in the greater sage-grouse during
necropsy. No clinical signs of the disease were observed.
West Nile virus was introduced into the northeastern United States
in 1999 and has subsequently spread across North America (Marra et al.
2004, p.394). This virus is thought to have caused millions of wild
bird deaths since its introduction (Walker and Naugle in press, p. 4),
but most WNv mortality goes unnoticed or unreported (Ward et al. 2006,
p. 101). The virus persists largely within a mosquito-bird-mosquito
infection cycle (McLean 2006, p. 45). However, direct bird-to-bird
transmission of the virus has been documented in several species
(McLean 2006, pp. 54, 59) including the greater sage-grouse (Walker and
Naugle in press, p. 13; Cornish 2009b, pers. comm.). The frequency of
direct transmission has not been determined (McLean 2006, p. 54).
Impacts of WNv on the bird host varies by species with some species
being relatively unaffected (e.g., common grackles (Quiscalus
quiscula)) and others experiencing mortality rates of up to 68 percent
(e.g., American crow (Corvus brachyrhynchos)) (Walker and Naugle in
press, p. 4, and references therein). Greater sage-grouse are
considered to have a high susceptibility to WNv, with resultant high
levels of mortality (Clark et al. 2006, p. 19; McLean 2006, p. 54).
In sagebrush habitats, WNv transmission is primarily regulated by
environmental factors, including temperature, precipitation, and
anthropogenic water sources, such as stock ponds and coal-bed methane
ponds, that support the mosquito vectors (Reisen et al. 2006, p. 309;
Walker and Naugle in press, pp. 10-12). Cold ambient temperatures
preclude mosquito activity and virus amplification, so transmission to
and in sage-grouse is limited to the summer (mid-May to mid-September)
(Naugle et al. 2005, p. 620; Zou et al. 2007, p. 4), with a peak in
July and August (Walker and Naugle in press, p. 10). Reduced and
delayed WNv transmission in sage-grouse has occurred in years with
lower summer temperatures (Naugle et al. 2005, p. 621; Walker et al.
2007b, p. 694). In non-sagebrush ecosystems, high temperatures
associated with drought conditions increase WNv transmission by
allowing for more rapid larval mosquito development and shorter virus
incubation periods (Shaman et al. 2005, p.134; Walker and Naugle in
press, p. 11). Greater sage-grouse congregate in mesic habitats in the
mid-late summer (Connelly et al. 2000, p. 971) thereby increasing the
risk of exposure to mosquitoes. If WNv outbreaks coincide with drought
conditions that aggregate birds in habitat near water sources, the risk
of exposure to WNv will be elevated (Walker and Naugle in press, p.
11).
Greater sage-grouse inhabiting higher elevation sites in summer are
likely less vulnerable to contracting WNv than birds at lower elevation
as ambient temperatures are typically cooler (Walker and Naugle in
press, p. 11). Greater sage-grouse populations in northwestern Colorado
and western Wyoming are examples of high elevation populations with
lower risk for impacts from WNv (Walker and Naugle in press, p. 26).
Also, due to
[[Page 13968]]
summer temperatures generally being lower in more northerly areas,
sage-grouse populations that are in geographically more northern
populations my be less susceptible than those at similar elevations
farther south (Naugle et al. 2005, cited in Walker and Naugle in press,
p. 11). Climate change could result in increased temperatures and thus
potentially exacerbate the prevalence of WNv, and thereby impacts on
greater sage-grouse, but this risk also depends on complex interactions
with other environmental factors including precipitation and
distribution of suitable water (Walker and Naugle in press, p. 12).
The primary vector of WNv in sagebrush ecosystems is Culex tarsalis
(Naugle et al. 2004, p. 711; Naugle et al. 2005, p. 617; Walker and
Naugle in press, p. 6). Individual mosquitoes may disperse as much as
18 km (11.2 mi) (Miller 2009, pers. comm.; Walker and Naugle in press,
p. 7). This mosquito species is capable of overwinter survival and,
therefore, can emerge as infected adults the following spring (Walker
and Naugle in press, p. 8 and references therein), thereby decreasing
the time for disease cycling (Miller 2009, pers. comm.). This ability
may increase the occurrence of this virus at higher elevation
populations or where ambient temperatures would otherwise be
insufficient to sustain the entire mosquito-virus cycle.
In greater sage-grouse, mortality from WNv occurs at a time of year
when survival is otherwise typically high for adult females (Schroeder
et al. 1999, p.14; Aldridge and Brigham 2003, p. 30), thus potentially
making these deaths additive and reducing average annual survival
(Naugle et al. 2005, p. 621). WNv has been identified as a source of
additive mortality in American white pelicans (Pelecanus
erythrorhynchos) in the northern plains breeding colonies (Montana,
North Dakota and South Dakota), and its continued impact has the
potential to severely impact the entire pelican population (Sovada et
al. 2008, p. 1030).
WNv was first detected in 2002 as a cause of greater sage-grouse
mortalities in Wyoming (Walker and Naugle in press, p. 15). Data from
four studies in the eastern half of the sage-grouse range (Alberta,
Montana, and Wyoming; MZ I) showed survival in these populations
declined 25 percent in July and August of 2003 as a result of the WNv
infection (Naugle et al. 2004, p. 711). Populations of sage-grouse that
were not affected by WNv showed no similar decline. Additionally,
individual sage-grouse in exposed populations were 3.4 times more
likely to die during July and August, the peak of WNv occurrence, than
birds in non-exposed populations (Connelly et al. 2004, p. 10-9; Naugle
et al. 2004, p. 711). Subsequent declines in both male and female lek
attendance in infected areas in 2004 compared with years before WNv
suggest outbreaks could contribute to local population extirpation
(Walker et al. 2004, p. 4). One outbreak near Spotted Horse, Wyoming in
2003 was associated with the subsequent extirpation of the local
breeding population, with five leks affected by the disease becoming
inactive within 2 years (Walker and Naugle in press, p. 16). Lek
surveys in northeastern Wyoming in 2004 indicated that regional sage-
grouse populations did not decline, suggesting that the initial effects
of WNv were localized (WGFD, unpublished data, 2004b).
Eight sage-grouse deaths resulting from WNv were identified in
2004: four from the Powder River Basin area of northeastern Wyoming and
southeastern Montana, one from the northwestern Colorado, near the town
of Yampa, and three in California (Naugle et al. 2005, p. 618). Fewer
other susceptible hosts succumbed to the disease in 2004, suggesting
that below average precipitation and summer temperatures may have
limited mosquito production and disease transmission rates (Walker and
Naugle in press, pp. 16-17). However, survival rates in greater sage-
grouse in July and September of that year were consistently lower in
areas with confirmed WNv mortalities than those without (avg. 0.86 and
0.96, respectively; Walker and Naugle in press, p. 17). There were no
comprehensive efforts to track sage-grouse mortalities outside of these
areas, so the actual distribution and extent of WNv in sage-grouse in
2004 is unknown (70 FR 2270).
Mortality rates from WNv in northeastern Wyoming and southeastern
Montana (MZ I) were between 2.4 (estimated minimum) and 28.9 percent
(estimated maximum) in 2005 (Walker et al. 2007b, p. 693). Sage-grouse
mortalities also were reported in California, Nevada, Utah, and
Alberta, but no mortality rates were calculated (Walker and Naugle in
press, p. 17). Mortality rates in 2006 in northeastern Wyoming ranged
from 5 to15 percent of radio-marked females (Walker and Naugle in
press, p. 17). Mortality rates in South Dakota among radio-marked
juvenile sage-grouse ranged between 6.5 and 71 percent in the same year
(Kaczor 2008, p. 63). Large sage-grouse mortality events, likely the
result of WNv, were reported in the Jordan Valley and near Burns,
Oregon (over 60 birds), and in several areas of Idaho and along the
Idaho-Nevada border (over 55 birds) (Walker and Naugle in press, p.
18). While most of the carcasses had decomposed and, therefore, were
not testable, results for the few that were tested showed that they
died from WNv. Mortality rates in these areas were not calculated.
However, the hunting season in Owyhee County, Idaho, was closed that
year due to the large number of birds that succumbed to the disease
(USGS 2006, p. 1; Walker and Naugle in press, p. 18).
In 2007, a WNv outbreak in South Dakota contributed to a 44-percent
mortality rate among 80 marked females (Walker and Naugle in press, p.
18). Juvenile mortality rates in 2007 in the same area ranged from 20.8
to 62.5 percent (Kaczor 2008, p. 63), reducing recruitment the
subsequent spring by 2 to 4 percent (Kaczor 2008, p. 65). Twenty-six
percent of radio-marked females in northeastern Montana died during a
2-week period immediately following the first detection of WNv in
mosquito pools. Two of those females were confirmed dead from WNv
(Walker and Naugle in press, p. 18). In the Powder River Basin, WNv-
related mortality among 85 marked females was between 8 and 21 percent
(Walker and Naugle in press, p. 18). A 52-percent decline in the number
of males attending leks in North Dakota between 2007 and 2008 also were
associated with WNv mortality in 2007 that prompted the State wildlife
agency to close the hunting season in 2008 (North Dakota Game and Fish
2008, entire) and 2009 (Robinson 2009, pers. comm.). The Duck Valley
Indian Reservation along the border of Nevada and Idaho closed their
hunting season in 2006 due to population declines resulting from WNv
(Gossett 2008, pers. comm.). WNv is still present in that area, with
continued population declines (50.3 percent of average males per lek
from 2005 to 2008) (Dick 2008, p. 2), and the hunting season remains
closed. The hunting season was closed in most of the adjacent Owyhee
County, Idaho for the same reason in both 2008 and 2009 (Dick 2008,
pers. comm.; IDFG 2009).
Only Wyoming reported WNv mortalities in sage-grouse in 2008
(Cornish 2009c, pers. comm.). However, with the exceptions of Colorado,
California, and Idaho, research on sage-grouse in other States is
limited, minimizing the ability to identify mortalities from the
disease, or recover infected birds before tissue deterioration
precludes testing. Three sage-grouse deaths were confirmed in 2009 in
Wyoming (Cornish 2009c, pers. comm.), two in Idaho (Moser 2009, pers.
comm.)
[[Page 13969]]
and one other is suspected in Utah (Olsen 2009, pers. comm.).
Greater sage-grouse deaths resulting from WNv have been detected in
10 States and 1 Canadian province. To date, no sage-grouse mortality
from WNv has been identified in either Washington State or
Saskatchewan. However, it is likely that sage-grouse have been infected
in Saskatchewan based on known patterns of sage-grouse in infected
areas of Montana (Walker and Naugle in press, p. 15). Also, WNv has
been detected in other species within the range of greater sage-grouse
in Washington (USGS 2009).
In 2005, we reported that there was little evidence that greater
sage-grouse can survive a WNv infection (70 FR 2270). This conclusion
was based on the lack of sage-grouse found to have antibodies to the
virus and from laboratory studies in which all sage-grouse exposed to
the virus, at varying doses, died within 8 days or less (70 FR 2270;
Clark et al. 2006, p. 17). These data suggested that sage-grouse do not
develop a resistance to the disease, and death is certain once an
individual is exposed (Clark et al. 2006, p. 18). However, 6 of 58
females (10.3 percent) birds captured in the spring of 2005 in
northeastern Wyoming and southeastern Montana were seropositive for
neutralizing antibodies, which suggests they were exposed to the virus
the previous fall and survived an infection. Additional, but
significantly fewer (2 of 109, or 1.8 percent) seropositive females
were found in the spring of 2006 (Walker et al. 2007b, p. 693). Of
approximately 1,400 serum tests on sage-grouse from South Dakota,
Montana, Wyoming and Alberta, only 8 tested positive for exposure to
WNv (Cornish 2009dpers. comm.), suggesting that survival is extremely
low. Seropositive birds have not been reported from other parts of the
species' range (Walker and Naugle in press, p. 20).
The duration of immunity conferred by surviving an infection is
unknown (Walker and Naugle in press, p. 20). It also is unclear whether
sage-grouse have sub-lethal or residual effects resulting from a WNv
infection, such as reduced productivity or overwinter survival (Walker
et al. 2007b, p. 694). Other bird species infected with WNv have been
documented to suffer from chronic symptoms, including reduced mobility,
weakness, disorientation, and lack of vigilance (Marra et al. 2004, p.
397; Nemeth et al. 2006, p. 253), all of which may affect survival,
reproduction, or both (Walker and Naugle in press, p. 20). Reduced
productivity in American white pelicans has been attributed to WNv
(Sovada et al. 2008, p.1030).
Several variants of WNv have emerged since the original
identification of the disease in the United States in 1999. One
variant, termed NY99, has proven to be more virulent than the original
virus strain of WNv, increasing the frequency of disease cycling
(Miller 2009, pers. comm.). This constant evolution of the virus could
limit resistance development in the greater sage-grouse.
Walker and Naugle (in press, pp. 20-24) modeled variability in
greater sage-grouse population growth for the next 20 years based on
current conditions under three WNv impact scenarios. These scenarios
included: (1) no mortalities from WNv; (2) WNv- related mortality based
on rates of observed infection and mortality rate data from 2003 to
2007; and (3) WNv-related mortality with increasing resistance to the
disease over time. The addition of WNv-related mortality (scenario 2)
resulted in a reduction of population growth. The proportion of
resistant individuals in the modeled population increased marginally
over the 20-year projection periods, from 4 to 15 percent, under the
increasing resistance scenario (scenario 3). While this increase in the
proportion of resistant individuals did reduce the projected WNv rates,
the authors caution that the presence of neutralizing antibodies in the
live birds does not always indicate that these birds are actually
resistant to infection and disease (Walker and Naugle in press, p. 25).
Additional models predicting the prevalence of WNv suggest that new
sources of anthropogenic surface waters (e.g., coal-bed methane
discharge ponds), increasing ambient temperatures, and a mosquito
parasite that reduces the length of time the virus is present in the
vector before the mosquito can spread the virus all suggest the impacts
of this disease are likely to increase (Miller 2008, pers. comm.).
However, the extent to which this will occur, and where, is unclear and
difficult to predict because several conditions that support the WNv
cycle must coincide for an outbreak to occur.
Human-created water sources in sage-grouse habitat known to support
breeding mosquitoes that transmit WNv include overflowing stock tanks,
stock ponds, irrigated agricultural fields, and coal-bed natural gas
discharge ponds (Zou et al. 2006, p. 1035). For example, from 1999
through 2004, potential mosquito habitats in the Powder River Basin of
Wyoming and Montana increased 75 percent (619 ha to 1084.5 ha; 1259 ac
to 2680) primarily due to the increase of small coal-bed natural gas
water discharge ponds (Zou et al. 2006, p. 1034). Additionally, water
developments installed in arid sagebrush landscapes to benefit wildlife
continue to be common. Several scientists have expressed concern
regarding the potential for exacerbating WNv persistence and spread due
to the proliferation of surface water features (e.g., Friend et al.,
2001, p. 298; Zou et al. 2006, p.1040; Walker et al. 2007b, p. 695;
Walker and Naugle in press, p. 27). Walker et al. (2007a, p. 694)
concluded that impacts from WNv will depend less on resistance to the
disease than on temperatures and changes in vector distribution. Zou et
al. (2006, p. 1040) cautioned that the continuing development of coal-
bed natural gas facilities in Wyoming and Montana contributes to
maintaining, and possibly increasing WNv on that landscape through the
maintenance and proliferation of surface water.
The long-term response of different sage-grouse populations to WNv
infections is expected to vary markedly depending on factors that
influence exposure and susceptibility, such as temperature, land uses,
and sage-grouse population size (Walker and Naugle in press, p. 25).
Small, isolated, or genetically limited populations are at higher risk
as an infection may reduce population size below a threshold where
recovery is no longer possible, as observed with the extirpated
population near Spotted Horse, Wyoming (Walker and Naugle in press, p.
25). Larger populations may be able to absorb impacts resulting from
WNv as long as the quality and extent of available habitat supports
positive population growth (Walker and Naugle in press, p. 25).
However, impacts from this disease may act synergistically with other
stressors resulting in reduction of population size, bird distribution,
or persistence (Walker et al. 2007a, p. 2652). WNv persists on the
landscape after it first occurs as an epizootic, suggesting this virus
will remain a long-term issue in affected areas (McLean 2006, p. 50).
Proactive measures to reduce the impact of WNv on greater sage-
grouse have been limited and are typically economically prohibitive.
Fowl vaccines used on captive sage-grouse were largely ineffective
(mortality rates were reduced from 100 to 80 percent in five birds)
(Clark et al. 2006, p. 17; Walker and Naugle in press, p. 27).
Development of a sage-grouse specific vaccine would require a market
incentive and development of an effective delivery mechanism for large
numbers of birds. Currently, the delivery mechanism is
[[Page 13970]]
via intramuscular injection (Marra et al. 2004, p. 399; Walker and
Naugle in press, p. 27), which is not feasible for wild populations.
Vaccinations would likely only benefit the individuals receiving the
vaccine, and not their offspring, so vaccination would have to occur on
an annual basis (Walker and Naugle in press, p. 27, and references
therein).
Mosquito production from human-created water sources could be
minimized if water produced during coal-bed natural gas development
were re-injected rather than discharged to the surface (Doherty 2007,
p. 81). Mosquito control programs for reducing the number of adult
mosquitoes may reduce the risk of WNv, but only if such methods are
consistently and appropriately implemented (Walker and Naugle in press,
p. 28). Many coal-bed natural gas companies in northeastern Wyoming (MZ
I) have identified use of mosquito larvicides in their management plans
(Big Horn Environmental Consultants in litt., 2009, p. 3). However, we
could find no information on the actual use of the larvicides or their
effectiveness. One experimental treatment in the area did report that
mosquito larvae numbers were less in ponds treated with larvicides than
those that were not (Big Horn Environmental Consultants in litt., 2009,
pp. 5-7) but statistical analyses were not conducted. While none of the
sage-grouse mortalities in the treated areas were due to WNv (Big Horn
Environmental Consultants 2009, p.3), the study design precluded actual
cause and effect analyses; therefore, the results are inconclusive. The
benefits of mosquito control in potentially reducing the incidence of
WNv in sage-grouse need to be considered in light of the potential
detrimental or cascading ecological effects of widespread spraying
(Marra et al. 2004, p. 401).
Small populations, such as the Columbia Basin area in Washington
State or the subpopulations within the Bi-State area along the
California and Nevada border also may be at high risk of extirpation
simply due to their low population numbers and the additive mortality
WNv causes (Christiansen and Tate, in press, p. 21). Larger populations
may be better able to sustain losses from WNv (Walker and Naugle in
press, p. 25) simply due to their size. However, as other impacts to
grouse and their habitats described under Factor A affect these areas,
these secure areas or sage-grouse ``refugia'' also may be at risk
(e.g., southwestern Wyoming, south-central Oregon). Existing and
developing models suggest that the occurrence of WNv is likely to
increase throughout the range of the species into the future.
Summary of Disease
Although greater sage-grouse are host to a wide variety of diseases
and parasites, few have resulted in population effects, with the
exception of WNv. Many large losses from bacterial and coccidial
infections have resulted when large groups of grouse were restricted to
limited habitats, such as springs and seeps in the late summer. If
these habitats become restricted due to habitat losses and degradation,
or changes in climate, these easily transmissible diseases may become
more prevalent. Sub-lethal effects of these disease and parasitic
infections on sage-grouse have never been studied, and, therefore, are
unknown.
Substantial new information on WNv and impacts on the greater sage-
grouse has emerged since we completed our finding in 2005. The virus is
now distributed throughout the species' range, and affected sage-grouse
populations experience high mortality rates with resultant, often large
reductions in local population numbers. Infections in northeastern
Wyoming, southeastern Montana, and the Dakotas seem to be the most
persistent, with mortalities recorded in that area every year since WNv
was first detected in sage-grouse. Limited information suggests that
sage-grouse may be able to survive an infection; however, because of
the apparent low level of immunity and continuing changes within the
virus, widespread resistance is unlikely.
There are few regular monitoring efforts for WNv in greater sage-
grouse; most detection is the result of research with radio-marked
birds, or the incidental discovery of large mortalities. In
Saskatchewan, where the greater sage-grouse is listed as an endangered
species, no monitoring for WNv occurs (McAdams 2009, pers. comm.).
Without a comprehensive monitoring program, the extent and effects of
this disease on greater sage-grouse rangewide cannot be determined.
However, it is clear that WNv is persistent throughout the range of the
greater sage-grouse, and is likely a locally significant mortality
factor. We anticipate that WNv will persist within sage-grouse habitats
indefinitely, and will remain a threat to greater sage-grouse until
they develop a resistance to the virus.
The most significant environmental factors affecting the
persistence of WNv within the range of sage-grouse are ambient
temperatures and surface water abundance and development. The continued
development of anthropogenic sources of warm standing water throughout
the range of the species will likely increase the prevalence of the
virus in sage-grouse, as predicted by Walker and Naugle (in press, pp.
20-24; see discussion above). Areas with intensive energy development
may be at a particularly high risk for continued WNv mortalities due to
the development of surface water features, and the continued loss and
fragmentation of habitats (see discussion of energy development above).
Resultant changes in temperature as a result of climate change also may
exacerbate the prevalence of WNv and thereby impacts on greater sage-
grouse unless they develop resistance to the virus.
With the exception of WNv, we could find no evidence that disease
is a concern with regard to sage-grouse persistence across the species'
range. WNv is a significant mortality factor for greater sage-grouse
when an outbreak occurs, given the bird's lack of resistance and the
continued proliferation of water sources throughout the range of the
species. However, a complex set of environmental and biotic conditions
that support the WNv cycle must coincide for an outbreak to occur.
Currently the annual patchy distribution of the disease is keeping the
impacts at a minimum. The prevalence of this disease is likely to
increase across the species' range.
We find that the threat of disease is not significant to the point
that the greater sage-grouse warrants listing under the Act as
threatened or endangered at this time.
Predation
Predation is the most commonly identified cause of direct mortality
for sage-grouse during all life stages (Schroeder et al. 1999, p. 9;
Connelly et al. 2000b, p. 228; Connelly et al. in press a, p. 23).
However, sage-grouse have co-evolved with a variety of predators, and
their cryptic plumage and behavioral adaptations have allowed them to
persist despite this mortality factor (Schroeder et al. 1999, p. 10;
Coates 2008 p. 69; Coates and Delehanty 2008, p. 635; Hagen in press,
p. 3). Until recently, there has been little published information that
indicates predation is a limiting factor for the greater sage-grouse
(Connelly et al. 2004, p. 10-1), particularly where habitat quality has
not been compromised (Hagen in press, p. 3). Although many predators
will consume sage-grouse, none specialize on the species (Hagen in
press, p. 5). However, generalist predators have the greatest effect on
ground nesting birds because
[[Page 13971]]
predator numbers are independent of prey density (Coates 2007, p. 4).
Major predators of adult sage-grouse include many species of
diurnal raptors (especially the golden eagle), red foxes, and bobcats
(Lynx rufus) (Hartzler 1974, pp. 532-536; Schroeder et al. 1999, pp.
10-11; Schroeder and Baydack 2001, p. 25; Rowland and Wisdom 2002, p.
14; Hagen in press, pp. 4-5). Juvenile sage-grouse also are killed by
many raptors as well as common ravens, badgers (Taxidea taxus), red
foxes, coyotes and weasels (Mustela spp.) (Braun 1995, entire;
Schroeder et al. 1999, p. 10). Nest predators include badgers, weasels,
coyotes, common ravens, American crows, and magpies (Pica spp.). Elk
(Holloran and Anderson 2003, p.309) and domestic cows (Bovus spp.)
(Coates et al. 2008, pp. 425-426), have been observed to eat sage-
grouse eggs. Ground squirrels (Spermophilus spp.) also have been
identified as nest predators (Patterson 1952, p. 107; Schroeder et al.
1999, p. 10; Schroeder and Baydack 2001, p. 25), but recent data show
that they are physically incapable of puncturing eggs (Holloran and
Anderson 2003, p 309; Coates et al. 2008, p 426; Hagen in press, p. 6).
Several other small mammals visited sage-grouse nests monitored by
videos in Nevada, but none resulted in predation events (Coates et al.
2008, p. 425). Great Basin gopher snakes (Pituophis catenifer
deserticola) were observed at nests, but no predation occurred.
Adult male greater sage-grouse are very susceptible to predation
while on the lek (Schroeder et al. 1999, p. 10; Schroeder and Baydack
2000, p. 25; Hagen in press, p. 5), presumably because they are very
conspicuous while performing their mating displays. Because leks are
attended daily by numerous birds, predators also may be attracted to
these areas during the breeding season (Braun 1995). Connelly et al.
(2000b, p.228) found that among 40 radio-collared males, 83 percent of
the mortality was due to predation and 42 percent of those mortalities
occurred during the lekking season (March through June). Adult female
greater sage-grouse are susceptible to predators while on the nest but
mortality rates are low (Hagen in press, p. 6). Hens will abandon their
nest when disturbed by predators (Patterson 1952, p. 110), likely
reducing this mortality (Hagen in press, p. 6). Connelly et al. (2000b,
p. 228) found that among 77 radio-collared adult hens that died, 52
percent of the mortality was due to predation, and 52 percent of those
mortalities occurred between March and August, which includes the
nesting and brood-rearing periods. Because sage-grouse are highly
polygynous with only a few males breeding per year, sage-grouse
populations are likely more sensitive to predation upon females.
Predation of adult sage-grouse is low outside the lekking, nesting, and
brood-rearing season (Connelly et al. 2000b, p. 230; Naugle et al.
2004, p. 711; Moynahan et al. 2006, p. 1536; Hagen in press, p. 6).
Estimates of predation rates on juveniles are limited due to the
difficulties in studying this age class (Aldridge and Boyce 2007, p.
509; Hagen in press, p.8). Chick mortality from predation ranged from
27 percent to 51 percent in 2002 and 10 percent to 43 percent in 2003
on three study sites in Oregon (Gregg et al. 2003a, p. 15; 2003b, p.
17). Mortality due to predation during the first few weeks after
hatching was estimated to be 82 percent (Gregg et al. 2007, p. 648).
Based on partial estimates from three studies, Crawford et al. (2004,
p. 4 and references therein) reported survival of juveniles to their
first breeding season was low, approximately 10 percent, and predation
was one of several factors they cited as affecting juvenile survival.
However, Connelly et al, (in press a, p. 19) point out that the
estimate of 10 percent survival of juveniles likely is biased low, as
at least two of the four studies that were the basis of this estimate
were from areas with fragmented or otherwise marginal habitat.
Sage-grouse nests are subject to varying levels of predation.
Predation can be total (all eggs destroyed) or partial (one or more
eggs destroyed). However, hens abandon nests in either case (Coates,
2007, p. 26). Gregg et al. (1994, p. 164) reported that over a 3-year
period in Oregon, 106 of 124 nests (84 percent) were preyed upon (Gregg
et al. 1994, p. 164). Non-predated nests had greater grass and forb
cover than predated nests. Patterson (1952, p.104) reported nest
predation rates of 41 percent in Wyoming. Holloran and Anderson (2003,
p. 309) reported a predation rate of 12 percent (3 of 26) in Wyoming.
In a 3-year study involving four study sites in Montana, Moynahan et
al. (2007, p. 1777) attributed 131 of 258 (54 percent) of nest failures
to predation in Montana, but the rates may have been inflated by the
study design (Connelly et al. in press a, p. 17). Re-nesting efforts
may compensate for the loss of nests due to predation (Schroeder 1997,
p. 938), but re-nesting rates are highly variable (Connelly et al. in
press a, p. 16). Therefore, re-nesting is unlikely to offset losses due
to predation. Losses of breeding hens and young chicks to predation
potentially can influence overall greater sage-grouse population
numbers, as these two groups contribute most significantly to
population productivity (Baxter et al. 2008, p. 185; Connelly et al, in
press a, p. 18).
Nesting success of greater sage-grouse is positively correlated
with the presence of big sagebrush and grass and forb cover (Connelly
et al. 2000, p. 971). Females actively select nest sites with these
qualities (Schroeder and Baydack 2001, p. 25; Hagen et al. 2007, p.
46). Nest predation appears to be related to the amount of herbaceous
cover surrounding the nest (Gregg et al. 1994, p. 164; Braun 1995;
DeLong et al. 1995, p. 90; Braun 1998; Coggins 1998, p. 30; Connelly et
al. 2000b, p. 975; Schroeder and Baydack 2001, p. 25; Coates and
Delehanty 2008, p. 636). Loss of nesting cover from any source (e.g.,
grazing, fire) can reduce nest success and adult hen survival. However,
Coates (2007, p. 149) found that badger predation was facilitated by
nest cover as it attracts small mammals, a badger's primary prey.
Similarly, habitat alteration that reduces cover for young chicks can
increase their rate of predation (Schroeder and Baydack 2001, p. 27).
In a review of published nesting studies, Connelly et al. (in press
a, p. 17) reported that nesting success was greater in unaltered
habitats versus altered habitats. Where greater sage-grouse habitat has
been altered, the influx of predators can decrease annual recruitment
into a population (Gregg et al. 1994, p. 164; Braun 1995; Braun 1998;
DeLong et al. 1995, p. 91; Schroeder and Baydack 2001, p. 28; Coates
2007, p. 2; Hagen in press, p. 7). Ritchie et al. (1994, p. 125),
Schroeder and Baydack (2001, p. 25), Connelly et al. (2004, p. 7-23),
and Summers et al. (2004, p. 523) have reported that agricultural
development, landscape fragmentation, and human populations have the
potential to increase predation pressure on all life stages of greater
sage-grouse by forcing birds to nest in less suitable or marginal
habitats, increasing travel time through habitats where they are
vulnerable to predation, and increasing the diversity and density of
predators.
Abundance of red fox and corvids, which historically were rare in
the sagebrush landscape, has increased in association with human-
altered landscapes (Sovada et al. 1995, p. 5). In the Strawberry Valley
of Utah, low survival of greater sage-grouse may have been due to an
unusually high density of red foxes, which apparently were attracted to
that area by anthropogenic activities (Bambrough et al. 2000). Ranches,
farms, and housing
[[Page 13972]]
developments have resulted in the introduction of nonnative predators
including domestic dogs (Canis domesticus) and cats (Felis domesticus)
into greater sage-grouse habitats (Connelly et al. 2004, p. 7-23).
Local attraction of ravens to nesting hens may be facilitated by loss
and fragmentation of native shrublands, which increases exposure of
nests to potential predators (Aldridge and Boyce 2007, p. 522; Bui
2009, p. 32). The presence of ravens was negatively associated with
grouse nest and brood fate (Bui 2009, p. 27).
Raven abundance has increased as much as 1500 percent in some areas
of western North America since the 1960s (Coates and Delehanty 2010, p.
244 and references therein). Human-made structures in the environment
increase the effect of raven predation, particularly in low canopy
cover areas, by providing ravens with perches (Braun 1998, pp.145-146;
Coates 2007, p. 155; Bui 2009, p. 2). Reduction in patch size and
diversity of sagebrush habitat, as well as the construction of fences,
powerlines, and other infrastructure also are likely to encourage the
presence of the common raven (Coates et al. 2008, p. 426; Bui 2009, p.
4). For example, raven counts have increased by approximately 200
percent along the Falcon-Gondor transmission line corridor in Nevada
(Atamian et al. 2007, p. 2). Ravens contributed to lek disturbance
events in the areas surrounding the transmission line (Atamian et al.
2007, p. 2), but as a cause of decline in surrounding sage-grouse
population numbers, it could not be separated from other potential
impacts, such as WNv.
Holloran (2005, p. 58) attributed increased sage-grouse nest
depredation to high corvid abundances, which resulted from
anthropogenic food and perching subsidies in areas of natural gas
development in western Wyoming. Bui (2009, p. 31) also found that
ravens used road networks associated with oil fields in the same
Wyoming location for foraging activities. Holmes (unpubl. data) also
found that common raven abundance increased in association with oil and
gas development in southwestern Wyoming. The influence of synanthropic
predators in the Wyoming Basin is important as this area has one of the
few remaining clusters of sagebrush landscapes and the most highly
connected network of sage-grouse leks (Knick and Hanser in press,
p.18). Raven abundance was strongly associated with sage-grouse nest
failure in northeastern Nevada, with resultant negative effects on
sage-grouse reproduction (Coates 2007, p. 130). The presence of high
numbers of predators within a sage-grouse nesting area may negatively
affect sage-grouse productivity without causing direct mortality.
Coates (2007, p. 85-86) suggested that ravens may reduce the time spent
off the nest by female sage-grouse, thereby potentially compromising
their ability to secure sufficient nutrition to complete the incubation
period.
As more suitable grouse habitat is converted to oil fields,
agriculture and other exurban development, grouse nesting and brood-
rearing become increasingly spatially restricted (Bui 2009, p. 32).
High nest densities which result from habitat fragmentation or
disturbance associated with the presence of edges, fencerows, or trails
may increase predation rates by making foraging easier for predators
(Holloran 2005, p. C37). In some areas even low but consistent raven
presence can have a major impact on sage-grouse reproductive behavior
(Bui 2009, p. 32). Leu and Hanser (in press, pp. 24-25) determined that
the influence of the human footprint in sagebrush ecosystems may be
underestimated due to varying quality of spatial data. Therefore, the
influence of ravens and other predators associated with human
activities may be under-estimated.
Predator removal efforts have sometimes shown short-term gains that
may benefit fall populations, but not breeding population sizes (Cote
and Sutherland 1997, p. 402; Hagen in press, p. 9; Leu and Hanser in
press, p. 27). Predator removal may have greater benefits in areas with
low habitat quality, but predator numbers quickly rebound without
continual control (Hagen in press, p. 9). Red fox removal in Utah
appeared to increase adult sage-grouse survival and productivity, but
the study did not compare these rates against other non-removal areas,
so inferences are limited (Hagen in press, p. 11). Slater (2003, p.
133) demonstrated that coyote control failed to have an effect on
greater sage-grouse nesting success in southwestern Wyoming. However,
coyotes may not be an important predator of sage-grouse. In a coyote
prey base analysis, Johnson and Hansen (1979, p. 954) showed that sage-
grouse and bird egg shells made up a very small percentage (0.4-2.4
percent) of analyzed scat samples. Additionally, coyote removal can
have unintended consequences resulting in the release of mesopredators,
many of which, like the red fox, may have greater negative impacts on
sage-grouse (Mezquida et al. 2006, p. 752). Removal of ravens from an
area in northeastern Nevada caused only short-term reductions in raven
populations (less than 1 year) as apparently transient birds from
neighboring sites repopulated the removal area (Coates 2007, p. 151).
Additionally, badger predation appeared to partially compensate for
decreases in raven removal (Coates 2007, p. 152). In their review of
literature regarding predation, Connelly et al. (2004, p. 10-1) noted
that only two of nine studies examining survival and nest success
indicated that predation had limited a sage-grouse population by
decreasing nest success, and both studies indicated low nest success
due to predation was ultimately related to poor nesting habitat. Bui
(2009, pp. 36-37) suggested removal of anthropogenic subsidies (e.g.,
landfills, tall structures) may be an important step to reducing the
presence of sage-grouse predators. Leu and Hanser (in press, p. 27)
also argue that reducing the effects of predation on sage-grouse can
only be effectively addressed by precluding these features.
Summary of Predation
Greater sage-grouse are adapted to minimize predation by cryptic
plumage and behavior. Because sage-grouse are prey, predation will
continue to be an effect on the species. Where habitat is not limited
and is of good quality, predation is not a threat to the persistence of
the species. However, sage-grouse may be increasingly subject to levels
of predation that would not normally occur in the historically
contiguous unaltered sagebrush habitats. The impacts of predation on
greater sage-grouse can increase where habitat quality has been
compromised by anthropogenic activities (such as exurban development,
road development) (e.g. Coates 2007, p. 154, 155; Bui 2009, p. 16;
Hagen in press, p. 12). Landscape fragmentation, habitat degradation,
and human populations have the potential to increase predator
populations through increasing ease of securing prey and subsidizing
food sources and nest or den substrate. Thus, otherwise suitable
habitat may change into a habitat sink for grouse populations (Aldridge
and Boyce 2007, p. 517). Anthropogenic influences on sagebrush habitats
that increase suitability for ravens may limit sage-grouse populations
(Bui 2009, p. 32). Current land-use practices in the intermountain West
favor high predator (in particular, raven) abundance relative to
historical numbers (Coates et al. 2008, p. 426). The interaction
between changes in habitat and predation may have substantial effects
at the landscape level (Coates 2007, p. 3).
The studies presented here suggest that, in areas of intensive
habitat
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alteration and fragmentation, sage-grouse productivity and, therefore,
populations could be negatively affected by increasing predation.
Predators could already be limiting sage-grouse populations in
southwestern Wyoming and northeastern Nevada (Coates 2007, p. 131; Bui
2009, p. 33).
The influence of synanthropic predators in southwestern Wyoming may
be particularly significant as this area has one of the few remaining
sagebrush landscapes and the most highly connected network of sage-
grouse leks (Wisdom et al. in press, p. 24). Unfortunately, except for
the few studies presented here, data are lacking that definitively link
sage-grouse population trends with predator abundance. However, where
habitats have been altered by human activities, we believe that
predation could be limiting local sage-grouse populations. As more
habitats face development, even dispersed development, we expect the
risk of increased predation to spread, possibly with negative effects
on the sage-grouse population trends. Studies of the effectiveness of
predator control have failed to demonstrate an inverse relationship
between the predator numbers and sage-grouse nesting success or
populations numbers.
Except in localized areas where habitat is compromised, we found no
evidence to suggest predation is limiting greater sage-grouse
populations. However, landscape fragmentation is likely contributing to
increased predation on this species.
Summary of Factor C
With regard to disease, the only concern is the potential effect of
WNv. This disease is distributed throughout the species' range and
affected sage-grouse populations experience high mortality rates (near
100 percent lethality), with resultant reductions in local population
numbers. Risk of exposure varies with factors such as elevation,
precipitation regimes, and temperature. The continued development of
anthropogenic water sources throughout the range of the species, some
of which are likely to provide suitable conditions for breeding
mosquitoes that are part of the WNv cycle, will likely increase the
prevalence of the virus in sage-grouse. We anticipate that WNv will
persist within sage-grouse habitats indefinitely and may be exacerbated
by factors (e.g., climate change) that increase ambient temperatures
and the presence of the vector on the landscape. The occurrence of WNv
occurrence is sporadic across the species' range, and a complex set of
environmental and biotic conditions that support the WNv cycle must
coincide for an outbreak to occur.
Where habitat is not limited and is of good quality, predation is
not a significant threat to the species. We are concerned that
continued landscape fragmentation will increase the effects of
predation on this species, potentially resulting in a reduction in
sage-grouse productivity and abundance in the future. However, there is
very limited information on the extent to which such effects might be
occurring. Studies of the effectiveness of predator control have failed
to demonstrate an inverse relationship between the predator numbers and
sage-grouse nesting success or population numbers, i.e., predator
removal activities have not resulted in increased populations.
Mortality due to nest predation by ravens or other human-subsidized
predators is increasing in some areas, but there is no indication this
is causing a significant rangewide decline in population trends. Based
on the best scientific and commercial information available, we
conclude that predation is not a significant threat to the species such
that the species requires listing under the Act as threatened or
endangered.
Factor D: Inadequacy of Existing Regulatory Mechanisms
Under this factor, we examine whether threats to the greater sage-
grouse are adequately addressed by existing regulatory mechanisms.
Existing regulatory mechanisms that could provide some protection for
greater sage-grouse include: (1) local land use laws, processes, and
ordinances; (2) State laws and regulations; and (3) Federal laws and
regulations. Regulatory mechanisms, if they exist, may preclude listing
if such mechanisms are judged to adequately address the threat to the
species such that listing is not warranted. Conversely, threats on the
landscape are exacerbated when not addressed by existing regulatory
mechanisms, or when the existing mechanisms are not adequate (or not
adequately implemented or enforced).
Local Land Use Laws, Processes, and Ordinances
Approximately 31 percent of the sagebrush habitats within the sage-
grouse MZs are privately owned (Table 3; Knick in press, p. 39) and are
subject only to local regulations unless Federal actions are associated
with the property (e.g., wetland modification, Federal subsurface
owner). We conducted extensive internet searches and contacted State
and local working group contacts from across the range of the species
to identify local regulations that may provide protection to the
greater sage-grouse. We identified only one regulation at the local
level that specifically addresses sage-grouse. Washington County,
Idaho, Planning and Zoning has developed a draft Comprehensive Plan
which states that ``Sage Grouse leks...and a buffer around those leks,
shall be protected from the disruption of development'' (Washington
County, 2009, p. 27). As this plan is still incomplete, and the final
buffer distance has not been identified, it cannot currently provide
the necessary regulatory provisions to be considered further. Sage-
grouse were mentioned in other county and local plans across the range,
and some general recommendations were made regarding effects to sage-
grouse associated with land uses. However, we could find no other
examples of county-planning and enforceable zoning regulations specific
to sage-grouse.
State Laws and Regulations
State laws and regulations may impact sage-grouse conservation by
providing specific authority for sage-grouse conservation over lands
which are directly owned by the State; providing broad authority to
regulate and protect wildlife on all lands within their borders; and
providing a mechanism for indirect conservation through regulation of
threats to the species (e.g. noxious weeds).
In general, States have broad authority to regulate and protect
wildlife within their borders. All State wildlife agencies across the
range of the species manage greater sage-grouse as resident native game
birds except for Washington (Connelly et al. 2004, p. 6-3). In
Washington, the species has been listed as a State-threatened species
since 1998 and is managed in accordance with the State's provisions for
such species (Stinson et al. 2004, p. 1). For example, killing greater
sage-grouse is banned in Washington, and State-owned agricultural and
grazing lands must adhere to standards regarding upland plant and
vegetative community health that protect habitat for the species
(Stinson et al. 2004, p. 55). However, lands owned by the Washington
Department of Natural Resources continue to be converted from sagebrush
habitat to croplands (Stinson et al. 2004, p. 55), which results in a
loss of habitat for sage-grouse. Therefore, the provisions to protect
sage-grouse in this State do not provide adequate protections for us to
consider.
All States across the range of greater sage-grouse have laws and
regulations
[[Page 13974]]
that identify the need to conserve wildlife populations and habitat,
including greater sage-grouse (Connelly et al. 2004, p. 2-22-11). As an
example, in Colorado, ``wildlife and their environment'' are to be
protected, preserved, enhanced and managed (Colorado Revised Statutes,
Title 33, Article 1-101 in Connelly et al. 2004, p. 2-3). Laws and
regulations in Oregon, Idaho, South Dakota, and California have similar
provisions (Connelly et al. 2004, pp. 2-2 to 2-4, 2-6 to 2-8). However,
these laws and regulations are general in nature and have not provided
the protection to sage-grouse habitat necessary to protect the species
from the threats described in Factor A above.
All of the states within the range of the sage-grouse have state
school trust lands that they manage for income to support their
schools. With the exception of Wyoming (see discussion below), none of
the states have specific regulations to ensure that the management of
the state trust lands is consistent with the needs of sage-grouse. Thus
there are currently no regulatory mechanisms on state trust lands to
ensure conservation of the species.
On September 26, 2008, the Governor of Nevada signed an executive
order calling for the preservation and protection of sage-grouse
habitat in the State of Nevada. The executive order directs the NDOW to
``continue to work with state and federal agencies and the interested
public'' to implement the Nevada sage-grouse conservation plan. The
executive order also directs other State agencies to coordinate with
the NDOW in these efforts. Although directed specifically at sage-
grouse conservation, the executive order is broadly worded and does not
outline specific measures that will be undertaken to reduce threats and
ensure conservation of sage-grouse in Nevada.
The California Environmental Quality Act (CEQA) (Public Resources
Code sections 21000-21177), requires full disclosure of the potential
environmental impacts of projects proposed in the State of California.
Section 15065 of the CEQA guidelines requires a finding of significance
if a project has the potential to ``reduce the number or restrict the
range of a rare or endangered plant or animal.'' Under these guidelines
sage-grouse are given the same protection as those species that are
officially listed within the State. However, the lead agency for the
proposed project has the discretion to decide whether to require
mitigation for resource impacts, or to determine that other
considerations, such as social or economic factors, make mitigation
infeasible (CEQA section 21002). In the latter case, projects may be
approved that cause significant environmental damage, such as
destruction of endangered species, their habitat, or their continued
existence. Therefore, protection of listed species through CEQA is
dependent upon the discretion of the agency involved, and cannot be
considered adequate protection for sage-grouse.
In Wyoming, the Governor issued an executive order on August 1,
2008, mandating special management for all State lands within sage-
grouse ``Core Population Areas'' (State of Wyoming 2008, entire). Core
Population Areas are important breeding areas for sage-grouse in
Wyoming as identified by the Wyoming ``Governor's Sage-Grouse
Implementation Team.'' In addition to identifying Core Population
Areas, the Team also recommended stipulations that should be placed on
development activities to ensure that existing habitat function is
maintained within those areas. Accordingly, the executive order
prescribes special consideration for sage-grouse, including
authorization of new activities only when the project proponent can
identify that the activity will not cause declines in greater sage-
grouse populations, in the Core Population Areas. These protections
will apply to slightly less than 23 percent of all sage-grouse habitats
in Wyoming, but account for approximately 80 percent of the total
estimated sage-grouse breeding population in the State. In February
2010, the Wyoming State Legislature adopted a joint resolution
endorsing Wyoming's core area strategy as outlined in the Governor'
Executive Order 2008-2.
On August 7, 2008, the Wyoming Board of Land Commissioners approved
the application of the Implementation Team's recommended stipulations
to all new development activities on State lands within the Core
Population Areas. These actions provide substantial regulatory
protection for sage-grouse in previously undeveloped areas on Wyoming
State lands. However, as they only apply to State lands, which are
typically single sections scattered across the State, the benefit to
sage-grouse is limited.
The executive order also applies to all activities requiring
permits from the Wyoming's Industrial Siting Council (ISC), including
wind power developments on all lands regardless of ownership in the
State of Wyoming. Developments outside of State land and not required
to receive an ISC permit (primarily developments that do not reach a
certain economic threshold) will not be required to follow the
stipulations. The application of the Governor's order to the Wyoming
ISC has the potential to provide significant regulatory protection for
sage-grouse from adverse effects associated with wind development (see
Energy, Factor A) and other developments.
There is still some uncertainty regarding what protective
stipulations will be applied to wind siting applications. The State of
Wyoming has indicated that it will enforce the Executive Order where
applicable, and on August 7, 2009, the Wyoming State Board of Land
Commissioners voted to withdraw approximately 400,000 ha (approximately
1 million ac) of land within the sage-grouse core areas from potential
wind development (State of Wyoming 2008, entire). The withdrawal order
states that ``there is no published research on the specific impacts of
wind energy on sage-grouse,'' and further states that permitting for
wind development should require data collection on the potential
effects of wind on sage-grouse. This action demonstrates a significant
action in the State of Wyoming to address future development activities
in core areas.
Wyoming's executive order does allow oil and gas leases on State
lands within core areas, provided those developments adhere to required
protective stipulations, which are consistent with published literature
(e.g. 1 well pad per section). The Service believes that the core area
strategy proposed by the State of Wyoming in Executive Order 2008-2, if
implemented by all landowners via -regulatory mechanisms, would provide
adequate protection for sage-grouse and their habitat in that State.
The protective measures associated with the Governor's order do not
extend to lands located outside the identified core areas but still
within occupied sage-grouse habitat. Where a siting permit is needed,
the application is de facto applied to all landownerships as the
Wyoming ISC cannot issue a permit without the protective stipulations
in place. In non-core areas, the minimization measures would be
implemented that are intended to maintain habitat conditions such that
there is a 50 percent likelihood that leks will persist over time (WGFD
2009, pp. 30-35). This approach may result in adverse effects to sage-
grouse and their habitats outside of the core areas (WGFD 2009, pp. 32-
35).
The Wyoming executive order states that current management and
existing land uses within the core areas should be recognized and
respected, thus we anticipate ongoing adverse effects
[[Page 13975]]
associated with those activities. The Service is working in
collaboration with the State of Wyoming Sage Grouse Implementation team
and other entities to continue to review and refine ongoing activities
in the core areas, as well as the size and location of the core areas
themselves to ensure the integrity and purpose of the core area
approach is maintained. Although this strategy provides excellent
potential for meaningful conservation of sage-grouse, it has yet to be
fully implemented. We believe that when fully realized, this effort
could ameliorate some threats to the greater sage-grouse.
On April 22, 2009, the Governor of Colorado signed into law new
rules for the Colorado Oil and Gas Conservation Commission (COGCC),
which is the entity responsible for permitting oil and gas well
development in Colorado (COGCC 2009, entire). The rules went into
effect on private lands on April 1, 2009, and on Federal lands July 1,
2009. The new rules require that permittees and operators determine
whether their proposed development location overlaps with ``sensitive
wildlife habitat,'' or is within restricted surface occupancy (RSO)
Area. For greater sage-grouse, areas within 1 km (0.6 mi) of an active
lek are designated as RSOs, and surface area occupancy will be avoided
except in cases of economic or technical infeasibility (CDOW, 2009, p.
12). Areas within approximately 6.4 km (4 mi) of an active lek are
considered sensitive wildlife habitat (CDOW, 2009, p. 13) and the
development proponent is required to consult with the CDOW to identify
measures to (1) avoid impacts on wildlife resources, including sage-
grouse; (2) minimize the extent and severity of those impacts that
cannot be avoided; and (3) mitigate those effects that cannot be
avoided or minimized (COGCC 2009, section 1202.a).
The COGCC will consider CDOW's recommendations in the permitting
decision, although the final permitting and conditioning authority
remains with COGCC. Section 1202.d of the new rules does identify
circumstances under which the consultation with CDOW is not required;
other categories for potential exemptions also can be found in the new
rules (e.g., 1203.b). The new rules will inevitably provide for greater
consideration of the conservation needs of the species, but the
potential decisions, actions, and exemptions can vary with each
situation, and consequently there is substantial uncertainty as to the
level of protection that will be afforded to greater sage-grouse. It
should be noted that leases that have already been approved but not
drilled (e.g., COGCC 2009, 1202.d(1)), or drilling operations that are
already on the landscape, may continue to operate without further
restriction into the future.
Some States require landowners to control noxious weeds, a habitat
threat to sage-grouse on their property, but the types of plants
considered to be noxious weeds vary by State. For example, only Oregon,
California, Colorado, Utah, and Nevada list Taeniatherum asperum as a
noxious, regulated weed, but T. asperum is problematic in other States
(e.g., Washington, Idaho). Colorado is the only western State that
officially lists Bromus tectorum as a noxious weed (USDA 2009), but B.
tectorum is invasive in many more States. These laws may provide some
protection for sage-grouse in areas, although large-scale control of
the most problematic invasive plants is not occurring, and
rehabilitation and restoration techniques are mostly unproven and
experimental (Pyke in press, p. 25).
State-regulated hunting of sage-grouse is permitted in all States
except Washington, where the season has been closed since 1988
(Connelly et al. 2004, p. 6-3). In States where hunting sage-grouse is
allowed, harvest levels can be adjusted annually, and the season and
limits are largely based on trend data gathered from spring lek counts
and previous harvest data. Management of hunting season length and bag
limits varies widely between States (see discussion of hunting
regulations in Factor B). States maintain flexibility in hunting
regulations through emergency closures or season changes in response to
unexpected events that affect local populations. For example, in areas
where populations are in decline or threats such as WNv have emerged,
some States have implemented harvest reductions or closures. There have
not been any studies demonstrating that hunting is the primary cause of
population declines in sage-grouse. Hunting regulations provide
adequate protection for the birds (see discussion under Factor B), but
do not protect the habitat. Therefore, the protection afforded through
this regulatory mechanism is limited.
Federal Laws and Regulations
Because it is not considered to be a migratory species, the greater
sage-grouse is not covered by the provisions of the Migratory Bird
Treaty Act (16 U.S.C. 703-712). However, several Federal agencies have
other legal authorities and requirements for managing sage-grouse or
their habitat. Federal agencies are responsible for managing
approximately 64 percent of the sagebrush habitats within the sage-
grouse MZs in the United States (Knick in press, p. 39, Table 3). Two
Federal agencies with the largest land management authority for
sagebrush habitats are the BLM and USFS. The U.S. Department of Defense
(DOD), DOE, and other agencies in DOI have responsibility for lands
and/or decisions that involve less than 5 percent of greater sage-
grouse habitat (Table 3).
Bureau of Land Management
Knick (in press, p. 39, Table 3) estimates that about 51 percent of
sagebrush habitat within the sage-grouse MZs is BLM-administered land;
this includes approximately 24.9 million ha (about 61.5 million ac).
The Federal Land Policy and Management Act of 1976 (FLPMA) (43 U.S.C.
1701 et seq.) is the primary Federal law governing most land uses on
BLM-administered lands, and directs development and implementation of
Resource Management Plans (RMPs) which direct management at a local
level. The greater sage-grouse is designated as a sensitive species on
BLM lands across the species' range (Sell 2010, pers comm.). The
management guidance afforded species of concern under BLM Manual 6840 -
Special Status Species Management (BLM 2008f) states that ``Bureau
sensitive species will be managed consistent with species and habitat
management objectives in land use and implementation plans to promote
their conservation and to minimize the likelihood and need for listing
under the ESA'' (BLM 2008f, p. .05V). BLM Manual 6840 further requires
that RMPs should address sensitive species, and that implementation
``should consider all site-specific methods and procedures needed to
bring species and their habitats to the condition under which
management under the Bureau sensitive species policies would no longer
be necessary'' (BLM 2008f, p. 2A1). As a designated sensitive species
under BLM Manual 6840, sage-grouse conservation must be addressed in
the development and implementation of RMPs on BLM lands.
RMPs are the basis for all actions and authorizations involving
BLM-administered lands and resources. They authorize and establish
allowable resource uses, resource condition goals and objectives to be
attained, program constraints, general management practices needed to
attain the goals and objectives, general implementation sequences,
intervals and standards for monitoring and evaluating RMPs to determine
effectiveness, and the need for amendment or revision (43 CFR 1601.0-
5(k)). The RMPs also provide a
[[Page 13976]]
framework and programmatic direction for implementation plans, which
are site-specific plans written to regulate decisions made in a RMP.
Examples include allotment management plans (AMPs) that address
livestock grazing, oil and gas field development, travel management,
and wildlife habitat management. Implementation plan decisions normally
require additional planning and NEPA analysis.
Of the existing 92 RMPs that include sage-grouse habitat, 82
contain specific measures or direction pertinent to management of sage-
grouse or their habitats (BLM 2008g, p. 1). However, the nature of
these measures and direction vary widely, with some measures directed
at a particular land use category (e.g., grazing management), and
others relevant to specific habitat use categories (e.g., breeding
habitat) (BLM 2008h). If an RMP contains specific direction regarding
sage-grouse habitat, conservation, or management, it represents a
regulatory mechanism that has the potential to ensure that the species
and its habitats are protected during permitting and other decision-
making on BLM lands. This section describes our understanding of how
RMPs are currently implemented in relation to sage-grouse conservation.
In addition to land use planning, BLM uses Instruction Memoranda
(IM) to provide instruction to district and field offices regarding
specific resource issues. Implementation of IMs is required unless the
IM provides discretion (Buckner 2009a. comm.). However, IMs are short
duration (1 to 2 years) and are intended to immediately address
resource concerns or provide direction to staff until a threat passes
or the resource issue can be addressed in a long-term planning
document. Because of their short duration, their utility and certainty
as a long-term regulatory mechanism may be limited if not regularly
renewed.
The BLM IM No. 2005-024 directed BLM State directors to ``review
all existing land use plans to determine the adequacy in addressing the
threats to sage-grouse and sagebrush habitat,'' and then to ``identify
and prioritize land use plan amendments or land use plan revisions
based upon the outcome.'' This IM instructed BLM State directors to
develop a process and schedule to update deficient land use plans to
adequately address sage-grouse and sagebrush conservation needs no
later than April 1, 2005. The BLM reports that all land use plan
revisions within sage-grouse habitat are scheduled for completion by
2015 (BLM, 2008g). To date, 14 plans have been revised, 31 are in
progress, and 19 are scheduled to be completed in the future. However,
the information provided to us by BLM did not specify what
requirements, direction, measures, or guidance has been included in the
newly revised RMPs to address threats to sage-grouse and sagebrush
habitat. Therefore, we cannot assess their value or rely on them as
regulatory mechanisms for the conservation of the greater sage-grouse.
On November 30, 2009, the BLM in Montana issued an IM that provides
guidance for sage-grouse management on lands under their authority in
MZs I and II (BLM 2009j, entire). The IM directs all state offices in
Montana to develop alternatives in ongoing and future RMP revisions for
activities that may affect the greater sage-grouse. The IM provides
guidance to mitigate impacts and BMPs for all proposed projects and
activities. While this IM will result in reduction of negative impacts
of projects authorized by the Montana BLM on sage-grouse, the way in
which the guidance will be interpreted and applied is uncertain and we
do not have a basis to assess whether or the extent to which it might
be effective in reducing threats. However, the IM is based on an
approach based on core areas in Montana, similar to the approach
implemented more formally in Wyoming. Therefore, it could be effective
in reducing impacts to sage-grouse habitat in the short term on BLM
lands in Montana. Unfortunately, the IM applies only to ongoing and
future RMPs, and does not apply to activities authorized under existing
RMPs. No expiration date was provided for this IM, but as discussed
above typical life expectancy of IMs is rarely greater than 2 years.
The BLM has regulatory authority over livestock grazing, OHV travel
and human disturbance, infrastructure development, fire management, and
energy development through FLPMA and associated RMP implementation, and
the Mineral Leasing Act (MLA) (30 U.S.C. 181 et seq.). The RMPs provide
a framework and programmatic guidance for AMPs that address livestock
grazing. In addition to FLPMA, BLM has specific regulatory authority
for grazing management provided at 43 CFR 4100 (Regulations on Grazing
Administration Exclusive of Alaska). Livestock grazing permits and
leases contain terms and conditions determined by BLM to be appropriate
to achieve management and resource condition objectives on the public
lands and other lands administered by the BLM, and to ensure that
habitats are, or are making significant progress toward being restored
or maintained for BLM special status species (43 CFR 4180.1(d)). Terms
and conditions that are attached to grazing permits are generally
mandatory. Across the range of sage-grouse, BLM required each BLM state
office to adopt rangeland health standards and guidelines by which they
measure allotment condition (43 CFR 4180 2(b)). Each state office
developed and adopted their own standards and guidelines based on
habitat type and other more localized considerations.
The rangeland health standards must address restoring, maintaining
or enhancing habitats of BLM special status species to promote their
conservation, and maintaining or promoting the physical and biological
conditions to sustain native populations and communities (43 CFR
4180.2(e)(9) and (10)). BLM is required to take appropriate action no
later than the start of the next grazing year upon determining that
existing grazing practices or levels of grazing use are significant
factors in failing to achieve the standards and conform with the
guidelines (43 CFR 4180.2(c)).
The BLM conducted national data calls in 2004 through 2008 to
collect information on the status of rangelands, rangeland health
assessments, and measures that have been implemented to address
rangeland health issues across sage-grouse habitats under their
jurisdiction. However, the information collected by BLM could not be
used to make broad generalizations about the status of rangelands and
management actions. There was a lack of consistency across the range in
how questions were interpreted and answered for the data call, which
limited our ability to use the results to understand habitat conditions
for sage-grouse on BLM lands. For example, one question asked about the
number of acres of land within sage-grouse habitat that was meeting
rangeland health standards. Field offices in more than three States
conducted the rangeland health assessments, and reported landscape
conditions at different scales (Sell 2009, pers. comm.). In addition,
the BLM data call reported information at a different scale than was
used for their landscape mapping (District or project level versus
national scale) (Buckner 2009b, pers. comm.). Therefore, we lack the
information necessary to assess how this regulatory mechanism effects
sage-grouse conservation.
The BLM's regulations require that corrective action be taken to
improve rangeland condition when the need is identified; however,
actions are not necessarily implemented until the permit renewal
process is initiated for the noncompliant parcel. Thus, there may be a
lag time between the allotment
[[Page 13977]]
assessment when necessary management changes are identified, and when
they are implemented. Although RMPs, AMPs, and the permit renewal
process provide an adequate regulatory framework, whether or not these
regulatory mechanisms are being implemented in a manner that conserves
sage-grouse is unclear. The BLM's data call indicates that there are
lands within the range of sage-grouse that are not meeting the
rangeland health standards necessary to conserve sage-grouse habitats.
In some cases management changes should occur, but such changes have
not been implemented (BLM 2008i).
The BLM uses regulatory mechanisms to address invasive species
concerns, particularly through the NEPA process. For projects proposed
on BLM lands, BLM has the authority to identify and prescribe best
management practices for weed management; where prescribed, these
measures must be incorporated into project design and implementation.
Some common best management practices for weed management may include
surveying for noxious weeds, identifying problem areas, training
contractors regarding noxious weed management and identification,
providing cleaning stations for equipment, limiting off-road travel,
and reclaiming disturbed lands immediately following ground disturbing
activities, among other practices. The effectiveness of these measures
is not documented.
The BLM conducts treatments for noxious and invasive weeds on BLM
lands, the most common being reseeding through the Emergency
Stabilization and Burned Area Rehabilitation Programs. According to BLM
data, 66 of 92 RMPs noted that seed mix requirements (as stated in
RMPs, emergency stabilization and rehabilitation, and other plans) were
sufficient to provide suitable sage-grouse habitat (e.g., seed
containing sagebrush and forb species)(Carlson 2008a). However, a
sufficient seed mix does not assure that restoration goals will be met;
many other factors (e.g., precipitation) influence the outcome of
restoration efforts.
Invasive species control is a priority in many RMPs. For example,
76 of the RMPs identified in the data call claim that the RMP (or
supplemental plans/guidance applicable to the RMP) requires treatment
of noxious weeds on all disturbed surfaces to avoid weed infestations
on BLM managed lands in the planning area (Carlson 2008a). Also, of the
82 RMPs that reference sage-grouse conservation, 51 of these
specifically address fire, invasives, conifer encroachment, or a
combination thereof (Carlson 2008, pers. comm.). We note that it is
possible that more RMPs are addressing invasives under another general
restoration category. In the 51 RMPs that address fire, invasives, and
conifer encroachment, they typically provide nonspecific guidance on
how to manage invasives. A few examples include: manage livestock in a
way that enhances desirable vegetation cover and reduces the
introduction of invasives, identify tools that may be used to control
invasives (e.g., manual, mechanical, biological, or chemical
treatments), utilize an integrated weed management program, and apply
seasonal restrictions on fire hazards, among other methods (Carlson
2008, pers. comm.). As with other agencies and organizations, the
extent to which these measures are implemented depends in large part on
funding, staff time, and other regulatory and non-regulatory factors.
Therefore, we cannot assess their value as regulatory mechanisms for
the conservation of the greater sage-grouse.
Herbicides also are commonly used on BLM lands to control
invasives. In 2007, the BLM completed a programmatic EIS (72 FR 35718)
and record of decision (72 FR 57065) for vegetation treatments on BLM-
administered lands in the western United States. This program guides
the use of herbicides for field-level planning, but does not authorize
any specific on-the-ground actions; site-specific NEPA analysis is
still required at the project level.
The BLM has one documented regulatory action to address wildfire
and protect of sage-grouse: National IM 2008-142 - 2008 Wildfire Season
and Sage-Grouse Conservation. This IM was issued on June 19, 2008, and
was effective through September 30, 2009. It provided guidance to BLM
State directors that conservation of greater sage-grouse and sagebrush
habitats should be a priority for wildfire suppression, particularly in
areas of the Great Basin (portions of WAFWA MZ III, IV, and V) (BLM
2008j, entire). At least one BLM State office within the range of sage-
grouse (Idaho) developed a State-level IM and guidance that prioritized
the protection of sage-grouse habitats during fire management
activities, in addition to the national IM which pertains to wildfire
suppression activities (BLM 2008k, entire).
While we do not know the extent to which these directives
alleviated the wildfire threat to sage-grouse (as described under
Factor A) during the 2008 and 2009 fire seasons, we believe that this
strategic approach to ameliorating the threat of fire is appropriate
and significant. Targeting the protection of important sage-grouse
habitats during fire suppression and fuels management activities could
help reduce loss of key habitat due to fire if directed through a long-
term, regulatory mechanism. Under Factor A, we describe why the threat
of wildfire is likely to continue indefinitely. This foreseeable future
requires a regulatory approach that addresses the threat over the long
term. The use of IMs to increase protection of sage-grouse habitat
during wildfire is not adequate to protect the species because IMs are
both short-term and have discretionary renewal (decisions made on a
case-by-case basis).
The BLM is the primary Federal agency managing the United States
energy resources on 102 million surface ha (253 million ac) and 283
million sub-surface ha (700 million ac) of mineral estate (BLM 2010).
Public sub-surface estate can be under public or private (i.e., split-
estate) surface. Over 7.3 million ha (18 million ac) of sage-grouse
habitats on public lands are leased for oil, gas, coal, minerals, or
geothermal exploration and development across the sage-grouse range
(Service 2008f). Energy development, particularly nonrenewable
development, has primarily occurred within sage-grouse MZs I and II.
The BLM has the legal authority to regulate and condition oil and
gas leases and permits under both FLPMA and the MLA. An amendment to
the Energy Policy and Conservation Act of 1975 (42 U.S.C. 6201 et seq.)
in 2000 (Energy Policy Act of 2000 (PL 106-469)) requires the Secretary
of the Interior to conduct a scientific inventory of all onshore
Federal lands to identify oil and gas resources underlying these lands
(42 U.S.C. 6217). The Energy Policy Act of 2005 (42 U.S.C. 15801 et
seq.) further requires the nature and extent of any restrictions or
impediments to the development of such resources be identified and
permitting and development be expedited on Federal lands (42 U.S.C.
15921). In addition, the 2005 Energy Policy Act orders the
identification of renewable energy sources (e.g., wind, geothermal) and
provides incentives for their development (42 U.S.C. 15851).
On May 18, 2001, President Bush signed Executive Order (E.O.) 13212
- Actions to Expedite Energy-Related Projects (May 22, 2001, 66 FR
28357), which states that the executive departments and agencies shall
take appropriate actions, to the extent consistent with applicable law,
to expedite projects that will increase the production, transmission,
or
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conservation of energy. The Executive Order specifies that this
includes expediting review of permits or taking other actions as
necessary to accelerate the completion of projects, while maintaining
safety, public health, and environmental protections. On October 23,
2009, nine Federal agencies signed a MOU to expedite the siting and
construction of qualified electric transmission within the United
States (Federal Agency MOU 2009). The MOU states that all existing
environmental review and safeguard processes will be fully maintained.
Therefore, we assume that this new MOU will not alter the regulatory
processes (e.g., RMPs, project specific NEPA analysis) currently in
place related to transmission siting on BLM lands.
Program-specific guidance for fluid minerals (including oil and
gas) in the BLM planning handbook (BLM 2005b, Appendix C pp. 23-24)
specifies that land use planning decisions will identify restrictions
on areas subject to leasing, including closures, as well as lease
stipulations. Stipulations are conditions that are made part of a lease
when the environmental planning record demonstrates the need to
accommodate various resources such as the protection of specific
wildlife species. Stipulations advise the lease holder that a wildlife
species in need of special management may be present in the area
defined by the lease, and certain protective measures may be required
in order to develop the mineral resource on that lease.
The handbook further specifies that all stipulations must have
waiver, exception, or modification criteria documented in the plan, and
notes that the least restrictive constraint to meet the resource
protection objective should be used (BLM 2005b, Appendix C pp. 23-24).
Waivers are permanent exemptions, and modifications are changes in the
terms of the stipulation. The BLM reports the issuance of waivers and
modifications as rare (BLM 2008i). Exceptions are a one-time exemption
to a lease stipulation. For example, a company may be issued an
exception to enter crucial winter habitat during a mild winter if an
on-the-ground survey verifies that sage-grouse are not using the winter
habitat or have left earlier than normal (BLM 2004, p. 86). In 2006 and
2007, of 1,716 mineral or right-of-way authorizations on Federal
surface in 42 BLM planning areas no waivers were issued; 24
modifications were issued and 115 exceptions were granted, 72 of which
were in the Great Divide planning area in Wyoming (BLM 2008i), one of
the densest population concentrations for sage-grouse.
Although the restrictive stipulations that are applied to permits
and leases vary, a 0.40-km (0.25-mi) radius around sage-grouse leks is
generally restricted to ``no surface occupancy'' during the breeding
season, and noise and development activities are often limited during
the breeding season within a 0.80- to 3.22-km (0.5- to 2-mi) radius of
sage-grouse leks. Although these are the most often-applied
stipulations, site-specific application is highly variable. For
example, language in the Randolph RMP in Utah states that no
exploration, drilling, or other development activities can occur during
the breeding season within 3.22 km (2 mi) of a known sage-grouse lek,
and that there are ``no exceptions to this stipulation'' (BLM 2008h).
Conversely, under the Platte River RMP in the Wind River Basin
Management Area of Wyoming, ``oil and gas development is a priority in
the area'' and ``discretionary timing stipulations protecting sage-
grouse nesting habitats...will not be applied'' (BLM 2008h). Most of
the RMPs that address oil, gas, or minerals development specify the
standard protective stipulations (BLM 2008h). The stipulations do not
apply to the operation or maintenance of existing facilities,
regardless of their proximity to sage-grouse breeding areas (BLM
2008h). In addition, approximately 73 percent of leased lands in known
sage-grouse breeding habitat have no stipulations at all (Service
2008f).
As noted above, a 0.4-km (0.25-mi) radius buffer is used routinely
by BLM and other agencies to minimize the impacts of oil and gas
development on sage-grouse breeding activity. The rationale for using a
0.4-km (0.25-mi) buffer as the basic unit for active lek protection is
not clear, as there is no support in published literature for this
distance affording any measure of protection (see also discussion under
Energy Development, above). Anecdotally, this distance appears to be an
artifact from the 1960s attempt to initiate planning guidelines for
sagebrush management and is not scientifically based (Roberts 1991).
The BLM stipulations most commonly attached to leases and permits are
inadequate for the protection of sage-grouse, and for the long-term
maintenance of their populations in those areas affected by oil and gas
development activities (Holloran 2005, pp. 57-60; Walker 2007, p.
2651). In some locations, the BLM is incorporating recommendations and
information from new scientific studies into management direction.
Wyoming BLM issued an IM on December 29, 2009 (BLM 2009k, entire) to
ensure their management of sage-grouse and their habitats are
consistent with the State of Wyoming's core area populations (see
discussion above). The IM applies to all BLM programs and activities
within Wyoming, with the exception of livestock grazing management. A
separate IM will be issued separately for this program. The December
2009 IM should have the same efficacy in ameliorating threats to the
sage-grouse in Wyoming. However, the IM is scheduled to expire on Sept.
30, 2011, and therefore its life is far shorter than the foreseeable
future (30 to 50 years, see discussion below) for energy development in
that state. However, we are optimistic that this IM will result in
short-term conservation benefits for sage-grouse in Wyoming.
As with fossil fuel sources, the production, purchase, and
facilitation of development of renewable energy products by Federal
entities and land management agencies is directed by the 2005 Energy
Policy Act and Presidential E.O. 13212. The energy development section
of Factor A describes in detail the development and operation of
renewable energy projects, including recent increases in wind, solar
and geothermal energy development. All of these activities require
ground disturbance, infrastructure, and ongoing human activities that
could adversely affect greater sage-grouse on the landscape. Recently
the BLM has begun developing guidance to minimize impacts of renewable
energy production on public lands. A ROD for ``Implementation of a Wind
Energy Development Program and Associated Land Use Plan Amendments''
(BLM 2005a, entire) was issued in 2005. The ROD outlines best
management practices (BMPs) for the siting, development and operation
of wind energy facilities on BLM lands. The voluntary guidance of the
BMPs do not include measures specifically intended to protect greater
sage-grouse, although they do provide the flexibility for such measures
to be required through site-specific planning and authorization (BLM
2005a, p. 2).
On December 19, 2008, the BLM issued IM 2009-043, which is intended
to serve as additional guidance for processing wind development
proposals. In that IM, which expires on September 30, 2010, BLM updates
or clarifies previous guidance documentation, including the Wind Energy
Development Policy, and best management practices from the wind energy
development programmatic EIS of 2005. The new guidance does not
[[Page 13979]]
provide specific recommendations for greater sage-grouse, and largely
defers decision-making regarding project siting, including
meteorological towers, to either the individual land use planning
process, or to the standard environmental compliance (i.e., NEPA)
process. In addition, it emphasizes the voluntary nature of the
Service's 2003 interim guidelines for minimizing the effects of wind
turbines on avian species and reiterates that incorporation of the
guidelines in BLM agency decisions was not mandatory (BLM 2008e).
BLM State offices in Oregon and Idaho issued explicit guidance
regarding siting of meteorological towers (IM OR-2008-014 and ID-2009-
006, respectively) which required siting restrictions for towers around
leks such that potential adverse effects to sage-grouse are avoided or
minimized. These IMs provided substantial regulatory protection for
sage-grouse; however, both of these IMs expired on September 30, 2009.
We anticipate that they will be renewed in FY 2010, but that is an
annual management decision by the respective State BLM offices, thus
the long-term certainty that such measures will remain in place is
unknown.
The BLM is currently in the process of developing programmatic-
level guidance for the development of solar and geothermal energy
projects. A draft programmatic EIS for geothermal development is
currently available (BLM and USFS 2008a, entire), and the draft
programmatic EIS for solar energy is under development (BLM and DOE
2008). We anticipate that solar and geothermal energy development will
increase in the future (see discussion under energy in Factor A), and
that the development of infrastructure associated with these projects
could affect sage-grouse. Final environmental guidance for solar and
geothermal energy development on BLM lands has not yet been issued or
implemented; thus, we cannot assess its adequacy or implications for
the conservation of sage-grouse.
Summary: BLM
The BLM manages the majority of greater sage-grouse habitats across
the range of the species. The BLM has broad regulatory authority to
plan and manage all land use activities on their lands including travel
management, energy development, grazing, fire management, invasive
species management, and a variety of other activities. As described in
Factor A, all of these factors have the potential to affect sage-
grouse, including direct effects to the species and its habitats. The
ability of regulatory mechanisms to adequately address the effects
associated with wildfire or invasive plant species such as Bromus
tectorum is limited due primarily to the nature of those factors and
how they manifest on the landscape. However, a regulatory mechanism
that requires BLM staff to target the protection of key sage-grouse
habitats during fire suppression or appropriate fuels management
activities could help address the threat of wildfire in some
situations. We recognize the use of IMs for this purpose, including
both at the national and State level (Idaho) (BLM 2008j and 2008k);
however, a long-term mechanism is necessary given the scale of the
wildfire threat and its likelihood to persist on the landscape in the
foreseeable future.
For other threats to sage-grouse on BLM lands, the BLM has the
regulatory authority to address them in a manner that will provide
protection for sage-grouse. However, BLM's current application of those
authorities in some areas falls short of meeting the conservation needs
of the species. This is particularly evident in the regulation of oil,
gas, and other energy development activities, both on BLM-administered
lands and on split-estate lands. Stipulations commonly applied by BLM
to oil and gas leases and permits do not adequately address the scope
of negative influences of development on sage-grouse (Holloran 2005,
pp. 57-60, Walker 2007, pp. 2651; see discussion under Factor A), with
the exception of the new 2010 IM issued by the BLM in Wyoming (see
discussion below). In addition, BLM's ability to waive, modify, and
allow exceptions to those stipulations without regard to sage-grouse
persistence further limits the adequacy of those regulatory mechanisms
in alleviating the negative impacts to the species associated with
energy development.
For other threats, such as grazing, our ability to assess the
application of existing regulatory mechanisms on a broad scale is
limited by the way that BLM collected and summarized their data on
rangeland health assessments and the implementation of corrective
measures, where necessary. The land use planning and activity
permitting processes, as well as other regulations available to BLM
give them the authority to address the needs of sage-grouse. However,
the extent to which they do so varies widely from RMP area to RMP area
across the range of the species. In many areas existing mechanisms (or
their implementation) on BLM lands and BLM-permitted actions do not
adequately address the conservation needs of greater sage-grouse, and
are exacerbating the effects of threats to the species described under
Factor A.
USDA Forest Service
The USFS has management authority for 8 percent of the sagebrush
area within the sage-grouse MZs (Table 3; Knick in press, p. 39). The
USFS estimated that sage-grouse occupy about 5.2 million ha (12.8
million ac) on national forest lands in the western United States (USFS
2008 Appendix 2, Table 1). Twenty-six of the 33 National Forests or
Grasslands across the range of sage-grouse contain moderately or highly
important seasonal habitat for sage-grouse (USFS 2008 Appendix 2, Table
2). Management of activities on national forest system lands is guided
principally by the National Forest Management Act (NFMA) (16 U.S.C.
1600-1614, August 17, 1974, as amended 1976, 1978, 1980, 1981, 1983,
1985, 1988, and 1990). NFMA specifies that the USFS must have a land
and resource management plan (LRMP) (16 U.S.C. 1600) to guide and set
standards for all natural resource management activities on each
National Forest or National Grassland. All of the LRMPs that currently
guide the management of sage-grouse habitats on USFS lands were
developed using the 1982 implementing regulations for land and resource
management planning (1982 Rule, 36 CFR 219).
Greater sage-grouse is designated as sensitive species on USFS
lands across the range of the species (USFS 2008, pp. 25-26).
Designated sensitive species require special consideration during land
use planning and activity implementation to ensure the viability of the
species on USFS lands and to preclude any population declines that
could lead to a Federal listing (USFS 2008, p. 21). Additionally,
sensitive species designations require analysis for any activity that
could have an adverse impact to the species, including analysis of the
significance of any adverse impacts on the species, its habitat, and
overall population viability (USFS 2008, p. 21). The specifics of how
sensitive species status has conferred protection to sage-grouse on
USFS lands varies significantly across the range, and is largely
dependent on LRMPs and site-specific project analysis and
implementation. Fourteen forests identify greater sage-grouse as a
Management Indicator Species (USFS 2008, Appendix 2, Table 2), which
requires them to establish objectives for the maintenance and
improvement of habitat for the species during all planning processes,
to the degree consistent with overall multiple use objectives of the
alternative (1982 Rule,
[[Page 13980]]
36 CFR 219.19(a)). Of the 33 National Forests that manage greater sage-
grouse habitat, 16 do not specifically address sage-grouse management
or conservation in their Forest Plans, and only 6 provide a high level
of detail specific to sage-grouse management (USFS 2008, Appendix 2,
Table 4).
Almost all of the habitats that support sage-grouse on USFS lands
also are open to livestock grazing (USFS 2008, p. 39). Under the Range
Rescissions Act of 1995 (P.L. 104-19), the USFS must conduct a NEPA
analysis to determine whether grazing should be authorized on an
allotment, and what resource protection provisions should be included
as part of the authorization (USFS 2008, p. 33). The USFS reports that
they use the sage-grouse habitat guidelines developed in Connelly et
al. (2000) to develop desired condition and livestock use standards at
the project or allotment level. However, USFS also reported that the
degree to which the recommended sage-grouse conservation and management
guidelines were incorporated and implemented under Forest Plans varied
widely across the range (USFS 2008, p. 45). We do not have the results
of rangeland health assessments or other information regarding the
status of USFS lands that provide habitat to sage-grouse and,
therefore, cannot assess the efficacy in conserving this species.
Energy development occurs on USFS lands, although to a lesser
extent than on BLM lands. Through NFMA, LRMPs, and the On-Shore Oil and
Gas Leasing Reform Act (1987; implementing regulations at 36 CFR 228,
subpart E), the USFS has the authority to manage, restrict, or attach
protective measures to mineral and other energy permits on USFS lands.
Similar to BLM, existing protective standard stipulations on USFS lands
include avoiding construction of new wells and facilities within 0.4 km
(0.25 mi), and noise or activity disturbance within 3.2 km (2.0 mi) of
active sage-grouse leks during the breeding season. As described both
in Factor A and above, this buffer is inadequate to prevent adverse
impacts to sage-grouse populations. For most LRMPs where energy
development is occurring, these stipulations also apply to hard mineral
extraction, wind development, and other energy development activities
in addition to fluid mineral extraction (USFS 2008, Appendix 1,
entire). The USFS is a partner agency with the BLM on the draft
programmatic EIS for geothermal energy development described above. The
Record of Decision for the EIS does not amend relevant LRMPs and still
requires project-specific NEPA analysis of geothermal energy
applications on USFS lands (BLM and USFS 2008b, p. 3).
The land use planning process and other regulations available to
the USFS give it the authority to adequately address the needs of sage-
grouse, although the extent to which they do so varies widely across
the range of the species. We do not have information regarding the
current land health status of USFS lands in relation to the
conservation needs of greater sage-grouse; thus, we cannot assess
whether existing conditions adequately meet the species' habitat needs.
Other Federal Agencies
Other Federal agencies in the DOD, DOE, and DOI (including the
Bureau of Indian Affairs, the Service, and National Park Service) are
responsible for managing less than 5 percent of sagebrush lands within
the United States (Knick 2008, p. 31). Regulatory authorities and
mechanisms relevant to these agencies' management jurisdictions include
the National Park Service Organic Act (39 Stat. 535; 16 U.S.C. 1, 2, 3
and 4), the National Wildlife Refuge System Administration Act (16
U.S.C. 668dd-668ee), and the Department of the Army's Integrated
Natural Resources Management Plans for their facilities within sage-
grouse habitats. Due to the limited amount of land administered by
these agencies, we have not described them in detail here. However,
most of these agencies do not manage specifically for greater sage-
grouse on their lands, except in localized areas (e.g., specific
wildlife refuges, reservations). One exception is DOD regulatory
mechanisms applicable within MZ VI, where half of the remaining sage-
grouse populations and habitats occur on their lands.
The Yakima Training Center (YTC), a U.S. Army facility, manages
land in Washington that is the primary habitat for one of two
populations of greater sage-grouse in that State. During the breeding
season, the YTC has restrictions on training activities for the
protection of sage-grouse. Leks have a 1-km (0.6-mi) buffer where all
training is excluded, and aircraft below 91.4 m (300 ft) are restricted
from midnight to 9 am from March 1 to May 15 (Stinson et al. 2004, p.
32). Sage-grouse protection areas also are identified, and training
activities are restricted in those areas during nesting and early brood
rearing periods (Stinson et al. 2004, p. 32). Other protections also
are provided. According to Stinson et al. (2004, p. 32), the ``YTC is
the only area in Washington where sage-grouse are officially protected
from disturbance during the breeding and brood-rearing period.''
However, the biggest concern for sage-grouse on the YTC is wildfire,
both natural and human-caused (Schroeder 2009, pers. comm.). Military
training activities occur across the YTC throughout the year, including
when there is high fire risk, and many fires are started every year
(Schroeder 2009, pers. comm.). Although the YTC has an active fire
response program, there are some fires most years that grow large, and
habitat is being burned faster than it can be replaced (Schroeder 2009,
pers. comm.). The protective stipulations to reduce disturbance to
greater sage-grouse are useful; however, current management, training
activities, and fire response, are resulting in habitat loss for the
species on the YTC.
The USDA Farm Service Agency manages the Conservation Reserve
Program (CRP) which pays landowners a rental fee to plant permanent
vegetation on portions of their lands, taking them out of agricultural
production (Schroeder and Vander Haegen in press, p. 4-5). These lands
are put under contract, typically for a 10-year period (Walker 2009,
pers. comm.). In some areas across the range of sage-grouse, and
particularly in Washington (Schroeder and Vander Haegen in press, p.
21), CRP lands provide important habitat for the species (see Factor A
discussion). Under the 2008 Farm Bill, several changes could reduce the
protection that CRP lands afford sage-grouse. First, the total acreage
that can be enrolled in the CRP program at any time has been reduced
from 15.9 million ha (39.2 million ac) to 12.9 million ha (32 million
ac) for 2010-2012 (USDA 2009a, p. 1). Second, no more than 25 percent
of the agricultural lands in any county can now be enrolled under CRP
contracts, although there are provisions to avoid this cap if
permission is granted by the County government (Walker 2009, pers.
comm.). Third, the 2008 Farm Bill authorized the BCAP, which provides
financial assistance to agricultural producers to establish and produce
eligible crops for the conversion to bioenergy products (USDA 2009b, p.
1). As CRP contracts expire, the BCAP program could result in greater
incentives to take land out of CRP and put it into production for
biofuels (Walker 2009, pers. comm.). All of these changes could affect
the amount of land in CRP, and in turn the habitat value provided to
greater sage-grouse. This change is of particular importance in
Washington, where CRP lands have been out of production long enough to
provide habitat for sage-grouse. Although the 2008 Farm Bill has been
[[Page 13981]]
signed into law, the implementing regulations and rules have not yet
been finalized. Thus, we cannot assess how the measures described above
will be implemented, and to what extent they may change the quantity or
quality of CRP land available for sage-grouse.
Canadian Federal and Provincial Laws and Regulations
Greater sage-grouse are federally protected in Canada as an
endangered species under schedule 1 of the Species at Risk Act (SARA;
Canada Gazette, Part III, Chapter 29, Volume 25, No. 3, 2002). Passed
in 2002, SARA is similar to the ESA and allows for habitat regulations
to protect sage-grouse (Aldridge and Brigham 2003, p. 31). The species
is also listed as endangered at the provincial level in Alberta and
Saskatchewan, and neither province allows harvest (Aldridge and Brigham
2003, p. 31). In Saskatchewan, sage-grouse are protected under the
Wildlife Habitat Protection Act, which protects sage-grouse habitat
from being sold or cultivated (Aldridge and Brigham 2003, p. 32). In
addition, sage-grouse are listed as endangered under the Saskatchewan
Wildlife Act, which restricts development within 500 m (1,640 ft) of
leks and prohibits construction within 1,000 m (3,281 ft) of leks
between March 15 and May 15 (Aldridge and Brigham 2003, p. 32). As
stated above, these buffers are inadequate to protect sage-grouse from
disturbance. In Alberta, individual birds are protected, but their
habitat is not (Aldridge and Brigham 2003, p. 32). Thus, although there
are some protections for the species in Canada, they are not sufficient
to assure conservation of the species.
Nonregulatory Conservation Measures
There are many non-regulatory conservation measures that may
provide local habitat protections. Although they are non-regulatory in
nature, they are here to acknowledge these programs. We have reviewed
and taken into account efforts being made to protect the species, as
required by the Act. Although some local conservation efforts have been
implemented and are effective in small areas, they are neither
individually nor collectively at a scale that is sufficient to
ameliorate threats to the species or populations. Many other
conservation efforts are being planned but there is substantial
uncertainty as to whether, where, and when they will be implemented,
and whether they will be effective; further, even if the efforts being
planned or considered become implemented and are effective in the
future, they are not a scale, either individually or collectively, to
be sufficient to ameliorate the threats to the species.
Other partnerships and agencies have also implemented broader-scale
conservation efforts. Cooperative Weed Management Areas (CWMAs) provide
a voluntary approach to control invasive species across the range of
sage-grouse. CWMAs are partnerships between Federal, State, and local
agencies, tribes, individuals, and interested groups to manage both
species designated by State agencies as noxious weeds, and invasive
plants in a county or multi-county geographical area. As of 2005,
Oregon, Nevada, Utah, and Colorado had between 75 and 89 percent of
their States covered by CWMAs or county weed districts, while
Washington, Idaho, Montana, and Wyoming had between 90 and 100 percent
coverage. Coverage in North Dakota is between 50 and 74 percent, and
South Dakota has less than 25 percent coverage (Center for Invasive
Plant Management 2008). Because these CWMAs are voluntary partnerships
we cannot be assured that they will be implemented nor can we predict
their effectiveness.
The Natural Resources Conservation Service (NRCS) of the USDA
provides farmers, ranchers, and other private landowners with technical
assistance and financial resources to support various management and
habitat restoration efforts. This includes helping farmers and ranchers
maintain and improve wildlife habitat as part of larger management
efforts, and developing technical information to assist NRCS field
staff with sage-grouse considerations when working with private
landowners. Because of the variable nature of the actions that can be
taken and the species they may address, some may benefit greater sage-
grouse, some may cause negative impacts (e.g., because they are aimed
at creating habitat conditions for other species that are inconsistent
with the needs of sage-grouse), or are neutral in their effects. In May
2008, Congress passed the Food, Conservation, and Energy Act of 2008
(2008 Farm Bill, P.L. 110-246). The Farm Bill maintains or extends
various technical and funding support programs for landowners. All
conservation programs under the Farm Bill are voluntary, unless binding
contracts for conservation planning or restoration are completed.
In 2006, WAFWA published the ``Greater Sage-Grouse Comprehensive
Conservation Strategy'' (Conservation Strategy; Stiver et al. 2006).
This document describes a range-wide framework to ``maintain and
enhance populations and distribution of sage-grouse'' (Stiver et al.
2006, p. ES-1). Although this framework is important to guiding
successful long-term conservation efforts and management of the greater
sage-grouse and its habitats, by design the WAFWA Conservation Strategy
is not regulatory in nature. Implementation of recommendations in the
Strategy by each signatory to the associated MOU is voluntary and few,
if any of the conservation recommendations have been implemented. Given
the lack of funding for this effort, we do not have the assurances that
implementation will occur. However, this is the most comprehensive
inter-agency strategy developed for this species and therefore, if the
principles identified are properly implemented it could have
significant positive impacts.
All of the States in the extant range of the greater sage-grouse
have finalized conservation or management plans for the species and its
habitats. These plans focus on habitat and population concerns at a
State level. The degree to which they consider and address mitigation
for a variety of threats varies substantially. For example, some plans
propose explicit strategies for minerals and energy issues (e.g.,
Montana) or wind energy development (e.g., Washington), and others more
generally acknowledge potential issues with energy development but do
not identify specific conservation measures (e.g., Nevada) (Stiver et
al. 2006, p. 2-24). These plans are in various stages of
implementation. The State level plans are not prescriptive, and
generally contain information to help guide the development and
implementation of more focused conservation efforts and planning at a
local level. We recognize the importance of these plans and
coordination efforts, but at this time cannot rely on them being
effectively implemented. Specific measures recommended in a State plan
that have been adopted into legal or regulatory frameworks (e.g., a
resource management plan), are assessed as regulatory mechanisms in the
discussion under Factor D.
The WDFW has designated sage-grouse habitat as a ``priority
habitat'' which classifies it as a priority for conservation and
management, and provides species and habitat information to interested
parties for land use planning purposes (Schroeder et al. 2003, pp. 17-4
to 17-6, Stinson et al. 2004, p. 31). However, the recommendations
provided under this program are guidelines, and we cannot be assured
they will be implemented. Similarly, programs like Utah's Watersheds
Restoration Initiative are partnership driven efforts intended to
[[Page 13982]]
conserve, manage, and restore habitats. We recognize projects and
cooperative efforts that are beneficial for sage-grouse may occur as a
result of this program.
Summary of Nonregulatory Conservation Efforts
There are several non-regulatory conservation efforts that address
impacts to the sage-grouse, mostly at a local scale (e.g. local working
group plans, CCAA). Their voluntary nature is appreciated, but their
implementation and effectiveness may be compromised as a result. We are
encouraged by the number and scale of these efforts, but lacking data
on exact locations, scale, and effectiveness, we do not know if threats
to the greater sage-grouse will be ameliorated as a result. We strongly
encourage implementation of the WAFWA Conservation Strategy as we
believe its implementation could be effective in reducing threats to
this species.
Summary of Factor D
To our knowledge, no current local land use or development planning
regulations provide adequate protection to sage-grouse from development
or other harmful land uses. Development and fragmentation of private
lands is a threat to greater sage-grouse (see discussion under Factor
A), and current local regulations do not adequately address this
threat.
Wyoming and Colorado have implemented State regulations regarding
energy development that could provide significant protection for
greater sage-grouse. In Wyoming, regulations regarding new energy
development have the potential to provide adequate protection to
greater sage-grouse by protecting core areas of the species' habitat.
BLM Wyoming has adopted Wyoming's approach for projects under their
authorities through a short-term IM. However, the restrictive
regulations do not apply to existing leases, or to habitats outside of
core areas. Thus, sage-grouse may continue to experience population-
level impacts associated with activities (e.g., energy development) in
Wyoming (see discussion under Factor A) both inside and outside core
areas. In Colorado, the regulations describe a required process rather
than a specific measure that can be evaluated; the regulations are only
recently in place and their implementation and effectiveness remains to
be seen.
The majority of sage-grouse habitat in the United States is managed
by Federal agencies (Table 3). The BLM and USFS have the legal
authority to regulate land use activities on their respective lands.
Under Factor A, we describe the ways that oil, natural gas, and other
energy development activities, fire, invasive species, grazing, and
human disturbance are or may be adversely affecting sage-grouse
populations and habitat. Overall, Federal agencies' abilities to
adequately address the issues of wildfire and invasive species across
the landscape, and particularly in the Great Basin, are limited.
However, we believe that new mechanisms could be adopted to target the
protection of sage-grouse habitats during wildfire suppression
activities or fuels management projects, which could help reduce this
threat in some situations. There is limited opportunity to implement
and apply new regulatory mechanisms that would provide adequate
protections or amelioration for the threat of invasive species. For
grazing, the regulatory mechanisms available to the BLM and USFS are
adequate to protect sage-grouse habitats; however, the application of
these mechanisms varies widely across the landscape. In some areas,
rangelands are not meeting the habitat standards necessary for sage-
grouse, and that contributes to threats to the species.
Our assessment of the implementation of regulations and associated
stipulations guiding energy development indicates that current measures
do not adequately ameliorate impacts to sage-grouse. Energy and
associated infrastructure development, including both nonrenewable and
renewable energy resources, are expected to continue to expand in the
foreseeable future. Unless protective measures consistent with new
research findings are widely implemented via a regulatory process,
those measures cannot be considered an adequate regulatory mechanism in
the context of our review. For the BLM and USFS, RMPs and LRMPs are
mechanisms through which adequate protections for greater sage-grouse
could be implemented. However, the extent to which appropriate measures
to conserve sage-grouse have been incorporated into those planning
documents, or are being implemented, varies across the range. As
evidenced by the discussion above, and the ongoing threats described
under Factor A, BLM and the USFS are not fully implementing the
regulatory mechanisms available to conserve greater sage-grouse on
their lands.
Based on our review of the best scientific and commercial
information available, we conclude that existing regulatory mechanisms
are inadequate to protect the species. The absence of adequate
regulatory mechanisms is a significant threat to the species, now and
in the foreseeable future.
Factor E: Other Natural or Manmade Factors Affecting the Species'
Continued Existence
Pesticides
Few studies have examined the effects of pesticides to sage-grouse,
but at least two have documented direct mortality of greater sage-
grouse from use of these chemicals. Greater sage-grouse died as a
result of ingestion of alfalfa sprayed with organophosphorus
insecticides (Blus et al. 1989, p. 1142; Blus and Connelly 1998, p.
23). In this case, a field of alfalfa was sprayed with methamidophos
and dimethoate when approximately 200 sage-grouse were present; 63 of
these sage-grouse were later found dead, presumably as a result of
pesticide exposure (Blus et al. 1989; p. 1142, Blus and Connelly 1998,
p. 23). Both methamidophos and dimethoate remain registered for use in
the United States (Christiansen and Tate in press, p. 21), but we found
no further records of sage-grouse mortalities from their use. In 1950,
Rangelands treated with toxaphene and chlordane bait in Wyoming to
control grasshoppers resulted in game bird mortality of 23.4 percent
(Christian and Tate in press, p. 20). Forty-five sage-grouse deaths
were recorded, 11 of which were most likely related to the pesticide
(Christiansen and Tate in press, p. 20, and references therein). Sage-
grouse who succumbed to vehicle collisions and mowing machines in the
same area also were likely compromised from pesticide ingestion
(Christian and Tate in press, p. 20). Neither of these chemicals has
been registered for grasshopper control since the early 1980s
(Christiansen and Tate in press, p. 20, and references therein).
Game birds that ingested sub-lethal levels of pesticides have been
observed exhibiting abnormal behavior that may lead to a greater risk
of predation (Dahlen and Haugen 1954, p. 477; McEwen and Brown 1966, p.
609; Blus et al. 1989, p. 1141). McEwen and Brown (1966, p. 689)
reported that wild sharp-tailed grouse poisoned by malathion and
dieldrin exhibited depression, dullness, slowed reactions, irregular
flight, and uncoordinated walking. Although no research has explicitly
studied the indirect levels of mortality from sub-lethal doses of
pesticides (e.g., predation of impaired birds), it has been assumed to
be the reason for mortality among some study birds (McEwen and Brown
1966 p. 609; Blus et al. 1989, p. 1142; Connelly and Blus 1991, p. 4).
Both Post (1951, p. 383) and Blus et al. (1989, p. 1142) located
depredated sage-grouse carcasses in areas that had been treated with
insecticides. Exposure to these
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insecticides may have predisposed sage-grouse to predation. Sage-grouse
mortalities also were documented in a study where they were exposed to
strychnine bait type used to control small mammals (Ward et al. 1942 as
cited in Schroeder et al. 1999, p. 16).
Cropland spraying may affect populations that are not adjacent to
agricultural areas, given the distances traveled by females with broods
from nesting areas to late brood-rearing areas (Knick et al. in press,
p. 17). The actual footprint of this effect cannot be estimated,
because the distances traveled to get to irrigated and sprayed fields
is unknown (Knick et al. in press, p. 17). Similarly, actual
mortalities from pesticides may be underestimated if sage-grouse
disperse from agricultural areas after exposure.
Much of the research related to pesticides that had either lethal
or sub-lethal effects on greater sage-grouse was conducted on
pesticides that have been banned or have their use further restricted
for more than 20 years due to their toxic effects on the environment
(e.g., dieldrin). We currently do not have any information to show that
the banned pesticides are presently having negative impacts to sage-
grouse populations through either illegal use or residues in the
environment. For example, sage-grouse mortalities were documented in a
study where they were exposed to strychnine bait used to control small
mammals (Ward et al. 1942 as cited in Schroeder et al. 1999, p. 16).
According to the U.S. Environmental Protection Agency (EPA), above-
ground uses of strychnine were prohibited in 1988 and those uses remain
temporarily cancelled today. We do not know when, or if, above ground
uses will be permitted to resume. Currently strychnine is registered
for use only below-ground as a bait application to control pocket
gophers (Thomomys sp.; EPA 1996, p. 4). Therefore, the current legal
use of strychnine baits is unlikely to present a significant exposure
risk to sage-grouse. No information on illegal use, if it occurs, is
available. We have no other information regarding mortalities or
sublethal effects of strychnine or other banned pesticides on sage-
grouse.
Although a reduction in insect population levels resulting from
insecticide application can potentially affect nesting sage-grouse
females and chicks (Willis et al. 1993, p. 40; Schroeder et al. 1999,
p. 16), we have no information as to whether insecticides are impacting
survivorship or productivity of the greater sage-grouse. Eng (1952, pp.
332,334) noted that after a pesticide was sprayed to reduce
grasshoppers, songbird and corvid nestling deaths ranged from 50 to 100
percent depending on the chemical used, and stated it appeared that
nestling development was adversely affected due to the reduction in
grasshoppers. Potts (1986 as cited in Connelly and Blus 1991, p. 93)
determined that reduced food supply resulting from the use of
pesticides ultimately resulted in high starvation rates of partridge
chicks (Perdix perdix). In a similar study on partridges, Rands (1985,
pp. 51-53) found that pesticide application adversely affected brood
size and chick survival by reducing chick food supplies.
Three approved insecticides, carbaryl, diflubenzuron, and
malathion, are currently available for application across the extant
range of sage-grouse as part of implementation of the Rangeland
Grasshopper and Mormon Cricket Suppression Control Program, under the
direction of the Animal and Plant Health Inspection Service (APHIS)
(APHIS 2004, entire). Carbaryl is applied as bait, while diflubenzuron
and malathion are sprayed. APHIS requires that application rates be in
compliance with EPA regulations, and APHIS has general guidelines for
buffer zones around sensitive species habitats. These pesticides are
only applied for grasshopper and Mormon cricket (Anabrus simplex)
control when requested by private landowners (APHIS 2004). Due to
delays in developing nationwide protocols for application procedures,
APHIS did not perform any grasshopper or Mormon cricket suppression
activities in 2006, 2007, or 2008 (Gentle 2008, pers. comm.). However,
due to an anticipated peak year of these pests in 2010, plans for
suppression are already in progress.
In the Rangeland Grasshopper and Mormon Cricket Suppression Program
Final Environmental Impact Statement--2002 (p.10), APHIS concluded that
there ``is little likelihood that the insecticide APHIS would use to
suppress grasshoppers would be directly or indirectly toxic to sage-
grouse. Treatments would typically not reduce the number of
grasshoppers below levels that are present in non-outbreak years.''
APHIS (2002, p. 69) stated that although ``malathion is also an
organophosphorus insecticide and carbaryl is a carbamate insecticide,
malathion and carbaryl are much less toxic to birds'' than other
insecticides associated with effects to sage-grouse or other wildlife.
The APHIS risk assessment (pp. 122-184) for this EIS determined that
the grasshopper treatments would not directly affect sage-grouse. As to
potential effects on prey abundance, APHIS noted that during
``grasshopper outbreaks when grasshopper densities can be 60 or more
per square meter (Norelius and Lockwood, 1999), grasshopper treatments
that have a 90 to 95 percent mortality still leave a density of
grasshoppers (3 to 6) that is generally greater than the average
density found on rangeland, such as in Wyoming, in a normal year
(Schell and Lockwood, 1997).''
Herbicide applications can kill sagebrush and forbs important as
food sources for sage-grouse (Carr 1968 as cited in Call and Maser
1985, p. 14). The greatest impact resulting from a reduction of either
forbs or insect populations is for nesting females and chicks due to
the loss of potential protein sources that are critical for successful
egg production and chick nutrition (Johnson and Boyce 1991, p. 90;
Schroeder et al. 1999, p. 16). A comparison of applied levels of
herbicides with toxicity studies of grouse, chickens, and other
gamebirds (Carr 1968, as cited in Call and Maser 1985, p. 15) concluded
that herbicides applied at recommended rates should not result in sage-
grouse poisonings.
In summary, pesticides can result in direct mortality of
individuals, and also can reduce the availability of food sources,
which in turn could contribute to mortality of sage-grouse. Despite the
potential effects of pesticides, we could find no information to
indicate that the use of these chemicals, at current levels, negatively
affects greater sage-grouse population numbers. Schroeder et al.'s
(1999, p.16) literature review found that the loss of insects can have
significant impacts on nesting females and chicks, but those impacts
were not detailed. Many of the pesticides that have been shown to have
an effect on sage-grouse have been banned in the United States for more
than 20 years. As previously noted, we currently do not have any
information to show that the banned pesticides through either illegal
use or residues in the environment are presently having negative
impacts to sage-grouse populations.
Contaminants
Greater sage-grouse exposure to various types of environmental
contaminants may potentially occur as a result of agricultural and
rangeland management practices, mining, energy development and pipeline
operations, nuclear energy production and research, and transportation
of materials along highways and railroads.
A single greater sage-grouse was found covered with oil and dead in
a wastewater pit associated with an oil
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field development in 2006; the site was in violation of legal
requirements for screening the pit (Domenici 2008, pers. comm.). To the
extent that this source of mortality occurs, it would be most likely in
MZ I and II, as those zones are where most of the oil and gas
development occurs in relation to occupied sage-grouse habitat. The
extent to which such mortality to greater sage-grouse is occurring is
extremely difficult to quantify due to difficulties in retrieving and
identifying oiled birds and lack of monitoring. We expect that the
number of sage-grouse occurring in the immediate vicinity of such
wastewater pits would be small due to the typically intense human
activity in these areas, the lack of cover around the pits, and the
fact that sage-grouse do not require free water. Most bird mortalities
recorded in association with wastewater pits are water-dependent
species (e.g., waterfowl), whereas dead ground-dwelling birds (such as
the greater sage-grouse) are rarely found at such sites (Domenici 2008,
pers. comm.). However, if the wastewater pits are not appropriately
screened, sage-grouse may have access to them and could ingest water
and/or become oiled while pursing insects. If these birds then return
to sagebrush cover and die their carcasses are unlikely to be found as
only the pits are surveyed. The effects of areal pollutants resulting
from oil and gas development on greater sage-grouse are discussed under
the energy development section in Factor A.
Numerous gas and oil pipelines occur within the occupied range of
several populations of the species. Exposure to oil or gas from
pipeline spills or leaks could cause mortalities or morbidity to
greater sage-grouse. Similarly, given the extensive network of highways
and railroad lines that occur throughout the range of the greater sage-
grouse, there is some potential for exposure to contaminants resulting
from spills or leaks of hazardous materials being conveyed along these
transportation corridors. We found no documented occurrences of impacts
to greater sage-grouse from such spills, and we do not expect they are
a significant source of mortality because these types of spills occur
infrequently and involve only a small area that might be within the
occupied range of the species.
Exposure of sage-grouse to radionuclides (radioactive atoms) has
been documented at the DOE's Idaho National Engineering Laboratory in
eastern Idaho. Although radionuclides were present in greater sage-
grouse at this site, there were no apparent harmful effects to the
population (Connelly and Markham 1983, pp. 175-176). There is one site
in the range formerly occupied by the species (Nuclear Energy Institute
2004), and construction is scheduled to begin on a new nuclear power
plant facility in 2009 in Elmore County, Idaho, near Boise (Nuclear
Energy Institute 2008) in MZ IV. At this new facility and any other
future facilities developed for nuclear power, if all provisions
regulating nuclear energy development are followed, it is unlikely that
there will be impacts to sage-grouse as a result of radionuclides or
any other nuclear products.
Recreational Activities
Boyle and Samson (1985, pp. 110-112) determined that non-
consumptive recreational activities can degrade wildlife resources,
water, and the land by distributing refuse, disturbing and displacing
wildlife, increasing animal mortality, and simplifying plant
communities. Sage-grouse response to disturbance may be influenced by
the type of activity, recreationist behavior, predictability of
activity, frequency and magnitude, activity timing, and activity
location (Knight and Cole 1995, p. 71). Examples of recreational
activities in sage-grouse habitats include hiking, camping, pets, and
off-highway vehicle (OHV) use. We have not located any published
literature concerning measured direct effects of recreational
activities on greater sage-grouse, but can infer potential impacts from
studies on related species and from research on non-recreational
activities. Baydack and Hein (1987, p. 537) reported displacement of
male sharp-tailed grouse at leks from human presence, resulting in loss
of reproductive opportunity during the disturbance period. Female
sharp-tailed grouse were observed at undisturbed leks while absent from
disturbed leks during the same time period (Baydack and Hein 1987, p.
537). Disturbance of incubating female sage-grouse could cause
displacement from nests, increased predator risk, or loss of nests.
However, disruption of sage-grouse during vulnerable periods at leks,
or during nesting or early brood rearing could affect reproduction or
survival (Baydack and Hein 1987, pp. 537-538).
Sage-grouse avoidance of activities associated with energy field
development (e.g., Holloran 2005, pp. 43, 53, 58; Doherty et al. 2008,
p. 194) suggests these birds are likely disturbed by any persistent
human presence. Additionally, Aldridge et al. (2008, p. 988) reported
that the density of humans in 1950 was the best predictor of
extirpation of greater sage-grouse. The authors also determined that
sage-grouse have been extirpated in virtually all counties reaching a
human population density of 25 people/km\2\ (65people/mi\2\) by 1950.
However, their analyses considered all impacts of human presence and
did not separate recreational activities from other associated
activities and infrastructure. The presence of pets in proximity to
sage-grouse can result in sage-grouse mortality or disturbance, and
increases in garbage from human recreationists can attract sage-grouse
predators and help maintain their numbers at increased levels (cite).
Leu et al. (2008, p. 1133) reported that slight increases in human
densities in ecosystems with low biological productivity (such as
sagebrush) may have a disproportionally negative impact on these
ecosystems due to the potentially reduced resiliency to anthropogenic
disturbance.
Indirect effects to sage-grouse from recreational activities
include impacts to vegetation and soils, and facilitating the spread of
invasive species. Payne et al. (1983, p. 329) studied off-road vehicle
impacts to rangelands in Montana, and found long-term (2 years)
reductions in sagebrush shrub canopy cover as the result of repeated
trips in the area. Increased sediment production and decreased soil
infiltration rates were observed after disturbance by motorcycles and
four-wheel drive trucks on two desert soils in southern Nevada (Eckert
et al. 1979, p. 395), and noise from these activities can cause
disturbance (Knick et al. in press, p.24).
Recreational use of OHVs is one of the fastest-growing outdoor
activities. In the western United States, greater than 27 percent of
the human population used OHVs for recreational activities between 1999
and 2004 (Knick et al., in press, p. 19). Off-highway vehicle use was a
primary factor listed for 13 percent of species either listed under the
Act or proposed for listing (Knick et al. in press, p. 24). Knick et
al. (in press, p. 1) reported that widespread motorized access for
recreation subsidized predators adapted to humans and facilitated the
spread of invasive plants. Any high-frequency human activity along
established corridors can affect wildlife through habitat loss and
fragmentation (Knick et al. in press, p. 25). The effects of OHV use on
sagebrush and sage-grouse have not been directly studied (Knick et al.
in press, p. 25). However, a review of local sage-grouse conservation
plans indicated that local working groups considered off-road vehicle
use to be a risk factor in many areas.
We are unaware of scientific reports documenting direct mortality
of greater sage-grouse through collision with off-
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road vehicles. Similarly, we did not locate any scientific information
documenting instances where snow compaction as a result of snowmobile
use precluded greater sage-grouse use, or affected their survival in
wintering areas. Off-road vehicle or snowmobile use in winter areas may
increase stress on birds and displace sage-grouse to less optimal
habitats. However, there is no empirical evidence available documenting
these effects on sage-grouse, nor could we find any scientific data
supporting the possibility that stress from vehicles during winter is
limiting greater sage-grouse populations.
Given the continuing influx of people into the western United
States (see discussion under Urbanization, Factor A; Leu and Hanser, in
press, p. 4), which is contributed to in part by access to recreational
opportunities on public lands, we anticipate effects from recreational
activity will continue to increase. The foreseeable future for this
effect spans for greater than 100 years, as we do not anticipate the
desire for outdoor recreational activities will diminish.
Life History Traits Affecting Population Viability
Sage-grouse have comparatively low reproductive rates and high
annual survival (Schroeder et al. 1999 pp. 11, 14; Connelly et al.
2000a, pp. 969-970), resulting in slower potential or intrinsic
population growth rates than is typical of other game birds. Therefore,
recovery of populations after a decline may require years. Also, as a
consequence of their site fidelity to breeding and brood-rearing
habitats (Lyon and Anderson 2003, p. 489), measurable population
effects may lag behind negative habitat impacts (Wiens and Rotenberry
1985, p. 666). While these natural history characteristics would not
limit sage-grouse populations across large geographic scales under
historical conditions of extensive habitat, they may contribute to
local population declines when humans alter habitats or mortality
rates.
Sage-grouse have one of the most polygamous mating systems observed
among birds (Deibert 1995, p. 92). Asymmetrical mate selection (where
only a few of the available members of one sex are selected as mates)
should result in reduced effective population sizes (Deibert 1995, p.
92), meaning the actual amount of genetic material contributed to the
next generation is smaller than predicted by the number of individuals
present in the population. With only 10 to 15 percent of sage-grouse
males breeding each year (Aldridge and Brigham 2003, p. 30), the
genetic diversity of sage-grouse would be predicted to be low. However,
in a recent survey of 16 greater sage-grouse populations, only the
Columbia Basin population in Washington showed low genetic diversity,
likely as a result of long-term population declines, habitat
fragmentation, and population isolation (Benedict et al. 2003, p. 308;
Oyler-McCance et al. 2005, p. 1307). The level of genetic diversity in
the remaining range of sage-grouse has generated a great deal of
interest in the field of behavioral ecology, specifically sexual
selection (Boyce 1990, p. 263; Deibert 1995, p. 92-93). There is some
evidence of off-lek copulations by subordinate males, as well as
multiple paternity within one clutch (Connelly et al. 2004, p. 8-2;
Bush 2009, p. 108). Dispersal also may contribute to genetic diversity,
but little is known about dispersal in sage-grouse (Connelly et al.
2004, p. 3-5). However, the lek breeding system suggests that
population sizes in sage-grouse must be greater than in non-lekking
bird species to maintain long-term genetic diversity.
Aldridge and Brigham (2003, p. 30) estimated that up to 5,000
individual sage-grouse may be necessary to maintain an effective
population size of 500 birds. Their estimate was based on individual
male breeding success, variation in reproductive success of males that
do breed, and the death rate of juvenile birds. We were unable to find
any other published estimates of minimal population sizes necessary to
maintain genetic diversity and long-term population sustainability in
sage-grouse. However, the minimum viable population size necessary to
sustain the evolutionary potential of a species (retention of
sufficient genetic material to avoid the effect of inbreeding
depression or deleterious mutations) has been estimated as high as an
adult population of 5,000 individuals (Traill et al. 2010, p. 32). Many
sage-grouse populations have already been estimated at well below that
value (see Garton et al. in press and discussions under Factor A),
suggesting their evolutionary potential (ability to persist long-term)
has already been compromised if that value is correct.
Drought
Drought is a common occurrence throughout the range of the greater
sage-grouse (Braun 1998, p. 148) and is considered a universal
ecological driver across the Great Plains (Knopf 1996, p.147).
Infrequent, severe drought may cause local extinctions of annual forbs
and grasses that have invaded stands of perennial species, and
recolonization of these areas by native species may be slow (Tilman and
El Haddi 1992, p. 263). Drought reduces vegetation cover (Milton et al.
1994, p. 75; Connelly et al. 2004, p. 7-18), potentially resulting in
increased soil erosion and subsequent reduced soil depths, decreased
water infiltration, and reduced water storage capacity. Drought also
can exacerbate other natural events such as defoliation of sagebrush by
insects. For example, approximately 2,544 km\2\ (982 mi\2\) of
sagebrush shrublands died in Utah in 2003 as a result of drought and
infestations with the Aroga (webworm) moth (Connelly et al. 2004, p. 5-
11). Sage-grouse are affected by drought through the loss of vegetative
habitat components, reduced insect production (Connelly and Braun 1997,
p. 9), and potentially exacerbation of WNv infections as described in
Factor C above. These habitat component losses can result in declining
sage-grouse populations due to increased nest predation and early brood
mortality associated with decreased nest cover and food availability
(Braun 1998, p. 149; Moynahan 2007, p. 1781).
Sage-grouse populations declined during the 1930s period of drought
(Patterson 1952, p. 68; Braun 1998, p. 148). Drought conditions in the
late 1980s and early 1990s also coincided with a period when sage-
grouse populations were at historically low levels (Connelly and Braun
1997, p. 8). From 1985 through 1995, the entire range of sage-grouse
experienced severe drought (as defined by the Palmer Drought Severity
Index) with the exceptions of north-central Colorado (MZ II) and
southern Nevada (MZ III). During this time period drought was
particularly prevalent in southwestern Wyoming, Idaho, central
Washington and Oregon, and northwest Nevada (University of Nebraska
2008). Abnormally dry to severe drought conditions still persist in
Nevada and western Utah (MZ III and IV), Idaho (MZ IV), northern
California and central Oregon (MZ V), and southwest Wyoming (MZ II)
(University of Nebraska 2008).
Aldridge et al. (2008, p. 992) found that the number of severe
droughts from 1950 to 2003 had a weak negative effect on patterns of
sage-grouse persistence. However, they cautioned that drought may have
a greater influence on future sage-grouse populations as temperatures
rise over the next 50 years, and synergistic effects of other threats
affect habitat quality (Aldridge et al. 2008, p. 992). Populations on
the periphery of the range may suffer extirpation during a severe and
prolonged drought (Wisdom et al. in press, p. 22).
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In summary, drought has been a consistent and natural part of the
sagebrush-steppe ecosystem and there is no information to suggest that
drought was a cause of persistent population declines of greater sage-
grouse under historic conditions. However, drought impacts on the
greater sage-grouse may be exacerbated when combined with other habitat
impacts that reduce cover and food (Braun 1998, p. 148).
Summary of Factor E
Numerous factors have caused sage-grouse mortality, and probably
morbidity, such as pesticides, contaminants, as well as factors that
contribute to direct and indirect disturbance to sage-grouse and
sagebrush, such as recreational activities. Drought has been correlated
with population declines in sage-grouse, but is only a limiting factor
where habitats have been compromised. Although we anticipate use of
pesticides, recreational activities, and fluctuating drought conditions
to continue indefinitely, we did not find any evidence that these
factors, either separately, or in combination are resulting in local or
range-wide declines of greater sage-grouse. New information regarding
minimum population sizes necessary to maintain the evolutionary
potential of a species suggests that sage-grouse in some areas
throughout their range may already be at population levels below that
threshold. This is a result of habitat loss and modification (discussed
under Factor A).
We have evaluated the best available scientific information on
other natural or manmade factors affecting the species' continued
existence and determined that this factor does not singularly pose a
significant threat to the species now or in the foreseeable future.
Findings
Finding on Petitions to List the Greater Sage-Grouse Across Its Entire
Range
As required by the Act, we have carefully examined the best
scientific and commercial information available in relation to the five
factors used to assess whether the greater sage-grouse is threatened or
endangered throughout all or a significant portion of its range. We
reviewed the petitions, information available in our files, other
available published and unpublished information, and other information
provided to us after our notice initiating a status review of the
greater sage-grouse was published. We also consulted with recognized
greater sage-grouse and sagebrush experts and other Federal and State
agencies.
In our analysis of Factor A, we identified and evaluated the
present or threatened destruction, modification, or curtailment of the
habitat or range of the greater sage-grouse from various causes,
including: habitat conversion for agriculture; urbanization;
infrastructure (e.g., roads, powerlines, fences) in sagebrush habitats;
fire; invasive plants; pinyon-juniper woodland encroachment; grazing;
energy development; and climate change. All of these, individually and
in combination, are contributing to the destruction, modification, or
curtailment of the greater sage-grouse's habitat or range. Almost half
of the sagebrush habitat estimated to have been present historically
has been destroyed. The impact has been greatly compounded by the
fragmented nature of this habitat loss, as fragmentation results in
functional habitat loss for greater sage-grouse even when otherwise
suitable habitat is still present. Although sagebrush habitats are
increasingly being destroyed, modified, and fragmented for multiple
reasons, the impact is especially great in relation to fire and
invasive plants (and the interaction between them) in more westerly
parts of the range, and energy development and related infrastructure
in more easterly areas. In addition, direct loss of habitat and
fragmentation is occurring due to agriculture, urbanization, and
infrastructure such as roads and powerlines built in support of several
activities. Some of these habitat losses due to these activities
occurred many years ago, but they continue to have an impact due to the
resulting fragmentation. Renewed interest in agricultural activities in
areas previously defined as unsuitable for these activities, due to
economic and technological incentives are likely to increase habitat
loss and fragmentation from agricultural conversion. Encroachment of
pinyon and juniper woodland into sagebrush is increasing and likely to
continue in several areas, altering the structure and composition of
habitat to the point that is it is greatly diminished or of no value to
sage-grouse. While effects of livestock grazing must be assessed
locally, the continued removal of sagebrush to increase forage directly
fragments habitat, and indirectly provides for fragmentation through
fencing and opportunities for invasive plant incursion. Habitat loss
and fragmentation also is very likely to increase as a result of
increased temperatures and changes in precipitation regimes associated
with the effects of climate change; also, the impacts of fire and
invasive plants likely already are, and will continue to be,
exacerbated by the effects of climate change.
Sagebrush restoration techniques are limited and generally
ineffective. Further, restoring full habitat function may not be
possible in some areas because alteration of vegetation, nutrient
cycles, topsoil, and cryptobiotic crusts have exceeded the point beyond
which recovery to pre-disturbance conditions or conditions suitable to
populations of greater sage-grouse, is possible.
The impacts to habitat are not uniform across the range; some areas
have experienced less habitat loss than others, and some areas are at
relatively lower risk than others for future habitat destruction or
modification. Nevertheless, the destruction and modification of habitat
has been substantial in many areas across the range of the species, it
is ongoing, and it will continue or even increase in the future. Many
current populations of greater sage-grouse already are relatively small
and connectivity of habitat and populations has been severely
diminished across much of the range; and further isolation is likely
for several populations. Even the Wyoming Basin and the Great Basin
area where Oregon, Nevada, and Idaho intersect, which are the two
stronghold areas with relatively large amounts of contiguous sagebrush
and sizeable populations of sage-grouse, are experiencing habitat
destruction and modification (e.g. as a result of oil and gas
development and other energy development in the Wyoming Basin) and this
will continue in the future. Several recent studies have demonstrated
that sagebrush area is one of the best landscape predictors of greater
sage-grouse persistence. Continued habitat destruction and
modification, compounded by fragmentation and diminished connectivity,
will result in reduced abundance and further isolation of many
populations over time, increasing their vulnerability to extinction.
Overall, this increases the risk to the entire species across its
range.
Therefore, based on our review of the best scientific and
commercial information available, we find that the present or
threatened destruction, modification, or curtailment of the habitat or
range of the greater sage-grouse is a significant threat to the species
now and in the foreseeable future.
During our review of the best scientific and commercial information
[[Page 13987]]
available, we found no evidence of risks from overutilization for
commercial, recreational, scientific, or education affecting the
species as a whole. Although the allowable harvest of sage-grouse
through hunting was very high in past years, substantial reductions in
harvest began during the 1990s and have continued to drop, and since
approximately 2000 total mortality due to hunting has been lower than
in the last 50 years. The present level of hunting mortality shows no
sign of being a significant threat to the species. However, in light of
present and threatened habitat loss (Factor A) and other considerations
(e.g. West Nile virus outbreaks in local populations), States and
tribes will need to continue to carefully manage hunting mortality,
including adjusting seasons and harvest levels, and imposing emergency
closures if needed. Therefore, we conclude that the greater sage-grouse
is not threatened by overutilization for commercial, recreational,
scientific, or educational purposes now or in the foreseeable future.
We found that while greater sage-grouse are subject to various
diseases, the only disease of concern is West Nile virus. Outbreaks of
WNv have resulted in disease-related mortality is local areas. Because
greater sage-grouse have little or no resistance to this disease, the
likelihood of mortality of affected individuals is extremely high.
Currently the annual patchy distribution of the disease is resulting in
minimal impacts except at local scales. We are concerned by the
proliferation of water sources associated with various human
activities, particularly water sources developed in association with
coal bed methane and other types of energy development, as they provide
potential breeding habitat for mosquitoes that can transmit WNv. We
expect the prevalence of this disease is likely to increase across much
of the species' range, but understand the long-term response of
different populations is expected to vary markedly. Further, a complex
set of conditions that support the WNv cycle must coincide for an
outbreak to occur, and consequently although we expect further
outbreaks will occur and may be more widespread, they likely will still
be patchy and sporadic. We found that while greater sage-grouse are
prey for numerous species, and that nest predation by ravens and other
human-subsidized predators may be increasing and of potential concern
in areas of human development, no information indicates that predation
is having or is expected to have an overall adverse effect on the
species. Therefore, at this time, we find that neither disease nor
predation is a sufficiently significant threat to the greater sage-
grouse now or in the foreseeable future that it requires listing under
the Act as threatened or endangered based on this factor.
Our review of the adequacy of existing regulatory mechanisms
included mechanisms in both Canada (less than 2 percent of the species'
range) and the United States. Greater sage-grouse are federally
protected in Canada as an endangered species under that country's
Species at Risk Act. The species also is listed as endangered by the
provinces of Alberta and Saskatchewan, and neither province allows
harvest. In Alberta, individual birds are protected, but their habitat
is not. The Saskatchewan Wildlife Act restricts development within 500
m (1,640 ft) of leks and prohibits construction within 1,000 m (3,281
ft) of leks from March 15 - May 15, but numerous studies have shown
these buffers are inadequate to protect sage-grouse, particularly in
nesting areas.
We found very few mechanisms in place at the level of local
governments that provide, either directly or indirectly, protections to
the greater sage-grouse or its habitat. The species receives some
protection under laws of each of the States currently occupied by
greater sage-grouse, including hunting regulations and various other
direct and indirect mechanisms. However, in most states these provide
little or no protection to greater sage-grouse habitat. Colorado
recently implemented State regulations regarding oil and gas
development, but they apply only to new developments and prescribe a
process rather than specific measures that we can evaluate or rely on
to provide protection related to the covered actions. In Wyoming, a
Governor's Executive Order (E. O. 2008-2) outlines a strategic
framework of core habitat areas that may provide the adequate scale of
conservation needed over time to ensure the long-term conservation of
greater sage-grouse in the state, but currently only the provisions for
Wyoming State lands show promise as regulatory mechanisms, affecting
only a small portion of the species' range in Wyoming.
The majority of greater sage-grouse habitat is on Federal land,
particularly areas administered by the Bureau of Land Management, and
to a lesser extent the U.S. Forest Service. We found a diverse network
of laws and regulations that relate directly or indirectly to
protections for the greater sage-grouse and its habitat on Federal
lands, including BLM and FS lands. However, the extent to which the BLM
and FS have adopted and adequately implemented appropriate measures to
conserve the greater sage-grouse and its habitat varies widely across
the range of the species. Regulatory mechanisms addressing the ongoing
threats related to habitat destruction and modification, particularly
as related to fire, invasive plants, and energy development, are not
adequate. There are no known existing regulatory mechanisms currently
in place at the local, State, national, or international level that
effectively address climate-induced threats to greater sage-grouse
habitat. In summary, based on our review of the best scientific
information available, we conclude that the inadequacy of existing
regulatory mechanisms is a significant threat to the greater sage-
grouse now and in the foreseeable future.
We assessed the potential risks from other natural or manmade
factors including pesticides, contaminants, recreational activities,
life history traits, and drought. We did not find any evidence these
factors, either separately or in combination, pose a risk to the
species. Therefore, we find that other natural and manmade factors
affecting the continued existence of the species do not threaten the
greater sage-grouse now or in the foreseeable future.
The greater sage-grouse occurs across 11 western States and 2
Canadian provinces and is a sagebrush obligate. Although greater sage-
grouse have a wide distribution, their numbers have been declining
since consistent data collection techniques have been implemented.
Recent local moderations in the decline of populations indicate a
period of relative population stability, particularly since the mid-
1990s. This trend information was one key basis for our decision in
2005 that listing the greater sage-grouse was not warranted. The
population trends appear to have continued to be relatively stable.
However, our understanding of the status of the species and the threats
affecting it has changed substantially since our decision in 2005. In
particular, numerous scientific papers and reports with new and highly
relevant information have become available, particularly during the
past year.
Although the declining population trends have moderated over the
past several years, low population sizes and relative lack of any sign
of recovery across numerous populations is troubling. Previously,
fluctuations in sage-grouse populations were apparent over time (based
on lek counts as an index). However, these have all but ceased for
several years, suggesting
[[Page 13988]]
some populations may be at a point where they are unable and unlikely
to increase due to habitat limitations, perhaps in combination with
other factors. Also, we are aware of the likelihood of a lag effect in
some areas, because population trend and abundance estimates are not
based on information about reproductive success and population
recruitment, but instead are based on the number of adult males
observed during lek counts. Because of the relative longevity of adult
sage-grouse, the lek counts of males could continue to suggest relative
stability even when a population is actually declining.
Overall, the range of the species is now characterized by numerous
relatively small populations existing in a patchy mosaic of
increasingly fragmented habitat, with diminished connectivity. Many
areas lack sufficient unfragmented sagebrush habitats on a scale, and
with the necessary ecological attributes (e.g., connectivity and
landscape context), needed to address risks to population persistence
and support robust populations. Relatively small and isolated
populations are more vulnerable to further reduction over time,
including increased risk of extinction due to stochastic events. Two
strongholds of relatively contiguous sagebrush habitat (southwestern
Wyoming and northern Nevada, southern Idaho, southeastern Oregon and
northwestern Utah) with large populations which are considered
strongholds for the species are also being impacted by direct habitat
loss and fragmentation that will continue for the foreseeable future.
We have reviewed and taken into account efforts being made to
protect the species, as required by the Act. Although some local
conservation efforts have been implemented and are effective in small
areas, they are neither individually nor collectively at a scale that
is sufficient to ameliorate threats to the species or populations. Many
other conservation efforts are being planned but there is substantial
uncertainty as to whether, where, and when they will be implemented,
and whether they will be effective.
We have carefully assessed the best scientific and commercial
information available regarding the present and future threats to the
greater sage-grouse. We have reviewed the petition, information
available in our files, and other published and unpublished
information, and consulted with recognized greater sage-grouse and
sagebrush experts. We have reviewed and taken into account efforts
being made to protect the species. On the basis of the best scientific
and commercial information available, we find that listing the greater
sage-grouse is warranted across its range. However, listing the species
is precluded by higher priority listing actions at this time, as
discussed in the Preclusion and Expeditious Progress section below.
We have reviewed the available information to determine if the
existing and foreseeable threats render the species at risk of
extinction now such that issuing an emergency regulation temporarily
listing the species as per section 4(b)(7) of the Act is warranted. We
have determined that issuing an emergency regulation temporarily
listing the greater sage-grouse is not warranted at this time (see
discussion of listing priority, below). However, if at any time we
determine that issuing an emergency regulation temporarily listing the
species is warranted, we will initiate this action at that time.
Finding on the Petition to List the Western Subspecies of the Greater
Sage-Grouse
As described in the Taxonomy section, above, we have reviewed the
best scientific information available on the geographic distribution,
morphology, behavior, and genetics of sage-grouse in relation to
putative eastern and western subspecies of sage-grouse, as formally
recognized by the AOU in 1957 (AOU 1957, p. 139). The AOU has not
published a revised list of subspecies of birds since 1957, and has
acknowledged that some of the subspecies probably cannot be validated
by rigorous modern techniques (AOU 1998, p. xii). The Service
previously made a finding that the eastern subspecies is not a valid
taxon and thus is not a listable entity (69 FR 933, January 7, 2004,),
and the Court dismissed a legal challenge to that finding (see Previous
Federal Action, above). Thus the 12-month petition finding we are
making here is limited to the petition to list the western subspecies.
To summarize the information presented in the Taxonomy section
(above), our status review shows the following with regard to the
putative western subspecies: (1) there is insufficient information to
demonstrate that the petitioned western sage-grouse can be
geographically differentiated from other greater sage-grouse throughout
the range of the taxon; (2) there is insufficient information to
demonstrate that morphological or behavioral aspects of the petitioned
western subspecies are unique or provide any strong evidence to support
taxonomic recognition of the subspecies; and (3) genetic evidence does
not support recognition of the western sage-grouse as a subspecies. To
be eligible for listing under the Act, an entity must fall within the
Act's definition of a species, ``*** any subspecies of fish or wildlife
or plants, and any distinct population segment of any species of
vertebrate fish or wildlife which interbreeds when mature'' (Act,
section 3(16)). Based on our review of the best scientific information
available, we conclude that the western subspecies is not a valid
taxon, and consequently is not a listable entity under the Act.
Therefore, we find that listing the western subspecies is not
warranted.
We note that greater sage-grouse covered by the petition to list
the putative western subspecies (except for those in the Bi-State area,
which are covered by a separate finding, below) are encompassed by our
finding that listing the greater sage-grouse rangewide is warranted but
precluded (see above). Further, greater sage-grouse within the Columbia
Basin of Washington were designated as warranted, but precluded for
listing as a DPS of the western subspecies in 2001 (65 FR 51578, May 7,
2001). However, with our finding that the western subspecies is not a
listable entity, we acknowledge that we must reevaluate the status of
the Columbia Basin population as it relates to the greater sage-grouse;
we will conduct this analysis as our priorities allow.
Finding on the Petitions to List the Bi-State Area (Mono Basin)
Population
As described above we received two petitions to list the Bi-State
(Mono Basin) area populations of greater sage-grouse as a Distinct
Population Segment. Please see the section titled ``Previous federal
actions'' for a detailed history and description of these petitions. In
order to make a finding on these petitions, we must first determine
whether the greater sage-grouse in the Bi-State area constitute a DPS,
and if so, we must conduct the relevant analysis of the five factors
that are the basis for making a listing determination.
Distinct Vertebrate Population Segment (DPS) Analysis
Under section 4(a)(1) of the Act, we must determine whether any
species is an endangered species or a threatened species because of any
of the five threat factors identified in the Act. Section 3(16) of the
Act defines ``species'' to include ``any subspecies of fish or wildlife
or plants, and any distinct population segment of any species of
vertebrate fish or wildlife which interbreeds when mature'' (16 U.S.C.
[[Page 13989]]
1532 (16)). To interpret and implement the distinct population segment
portion of the definition of a species under the Act and Congressional
guidance, the Service and the National Marine Fisheries Service (now
the National Oceanic and Atmospheric Administration-Fisheries)
published, on February 7, 1996, an interagency Policy Regarding the
Recognition of Distinct Vertebrate Population Segments under the Act
(61 FR 4722) (DPS Policy). The DPS Policy allows for more refined
application of the Act that better reflects the conservation needs of
the taxon being considered and avoids the inclusion of entities that
may not warrant protection under the Act.
Under our DPS Policy, we consider three elements in a decision
regarding the status of a possible DPS as endangered or threatened
under the Act. We apply them similarly for additions to the List of
Endangered and Threatened Wildlife, reclassification, and removal from
the List. They are: (1) Discreteness of the population segment in
relation to the remainder of the taxon; (2) the significance of the
population segment to the taxon to which it belongs; and (3) the
population segment's conservation status in relation to the Act's
standards for listing (whether the population segment is, when treated
as if it were a species, endangered or threatened). Discreteness is
evaluated based on specific criteria provided in the DPS Policy. If a
population segment is considered discrete under the DPS Policy we must
then consider whether the discrete segment is ``significant'' to the
taxon to which it belongs. If we determine that a population segment is
discrete and significant, we then evaluate it for endangered or
threatened status based on the Act's standards. The DPS evaluation in
this finding concerns the Bi-State (Mono Basin) area greater sage-
grouse that we were petitioned to list as threatened or endangered, as
stated above.
Discreteness Analysis
Under our DPS Policy, a population segment of a vertebrate species
may be considered discrete if it satisfies either one of the following
conditions: (1) It is markedly separated from other populations of the
same taxon as a consequence of physical, physiological, ecological, or
behavioral factors (quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation); or
(2) it is delimited by international governmental boundaries within
which differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act.
Markedly Separated From Other Populations of the Taxon
Bi-State area greater sage-grouse are genetically unique compared
with other populations of greater sage-grouse. Investigations using
both mitochondrial DNA sequence data and data from nuclear
microsatellites have demonstrated that Bi-State area greater sage-
grouse contain a large number of unique haplotypes not found elsewhere
within the range of the greater sage-grouse (Benedict et al. 2003, p.
306; Oyler-McCance et al. 2005, p. 1300). The genetic diversity present
in the Bi-State population was comparable to other populations
suggesting that the differences were not due to a genetic bottleneck or
founder event (Oyler-McCance and Quinn in press, p. 18). These genetic
studies provide evidence that the present genetic uniqueness exhibited
by Bi-State area greater sage-grouse developed over thousands and
perhaps tens of thousands of years (Benedict et al. 2003, p. 308;
Oyler-McCance et al. 2005, p. 1307), which predates Euro-American
settlement.
The Service's DPS Policy states that quantitative measures of
genetic or morphological discontinuity may be used as evidence of the
marked separation of a population from other populations of the same
taxon. In the Bi-State area, the present genetic uniqueness is most
likely a manifestation of prehistoric physical isolation. Based on the
reported timeline (thousands to tens of thousands of years) (Benedict
et al. 2003, p. 308), isolation of this population may have begun
during the Wisconsin Stage of the Pleistocene Epoch (from approximately
25,000 to 9,000 years before present (ybp)), when Ancient Lake Lahontan
covered much of western Nevada. After the lake receded (approximately
9,000 ybp), barriers to genetic mixing remained. Physical barriers in
the form of inhospitable habitats (Sierra-Nevada Mountains, salt desert
scrub, Mojave Desert) in most directions maintained this isolation.
With the establishment of Virginia City, Nevada (1859), any available
corridor that connected the Bi-State area to the remainder of the
greater sage-grouse range was removed.
Currently, no greater sage-grouse occur in the Virginia Range,
having been extirpated several decades ago. The population in closest
proximity to the Bi-State area occurs in the Pah Rah Range to the
northeast of Reno, Nevada, and approximately 50 km (31 mi) to the north
of the Bi-State area. The Pah Rah Range occurs immediately to the north
of the Virginia Range and south of the Virginia Mountains. It is
currently unknown if the small remnant population occurring in the Pah
Rah Range aligns more closely with the Bi-State birds or the remainder
of the greater sage-grouse. The range delineation occurs south of the
Virginia Mountains in one of three locations: (1) the small population
occurring in the Pah Rah Range, (2) the extirpated population
historically occurring in the Virginia Range, or (3) the Pine Nut
Mountains. Limited studies of behavioral differences between the Bi-
State population and other populations have not demonstrated any gross
differences that suggest behavioral barriers (Taylor and Young 2006, p.
39).
Conclusion for Discreteness
We conclude the Bi-State population of greater sage-grouse is
markedly separate from other populations of the greater sage-grouse
based on genetic data from mitochondrial DNA sequencing and from
nuclear microsatellites. The Bi-State area greater sage-grouse contain
a large number of unique haplotypes not found elsewhere within the
range of the species. The present genetic uniqueness exhibited by Bi-
State area greater sage-grouse occurred over thousands and perhaps tens
of thousands of years (Benedict et al. 2003, p. 308; Oyler-McCance et
al. 2005, p. 1307) and continues through today due to physical
isolation from the remainder of the range. These genetic data are the
principal basis for our conclusion that the Bi-State area greater sage-
grouse are markedly separated from other populations of greater sage-
grouse and therefore are discrete under the Service's DPS Policy.
Significance Analysis
The DPS Policy states that if a population segment is considered
discrete under one or both of the discreteness criteria, its biological
and ecological significance will then be considered in light of
Congressional guidance that the authority to list DPSs be used
``sparingly'' while encouraging the conservation of genetic diversity.
In carrying out this examination, the Service considers available
scientific evidence of the DPS's importance to the taxon to which it
belongs. As specified in the DPS Policy, this consideration of the
significance may include, but is not limited to, the following: (1)
persistence of the discrete population segment in an ecological setting
unusual or unique to the taxon; (2) evidence that its loss would result
in a significant gap in the range of the taxon; (3) evidence that it
[[Page 13990]]
is the only surviving natural occurrence of a taxon that may be more
abundant elsewhere as an introduced population outside its historical
range; or (4) evidence that the discrete population segment differs
markedly from other populations of the species in its genetic
characteristics. The DPS Policy further states that because precise
circumstances are likely to vary considerably from case to case, it is
not possible to describe prospectively all the classes of information
that might bear on the biological and ecological importance of a
discrete population segment.
(1) Persistence of the discrete population segment in an ecological
setting unusual or unique to the taxon. The Bi-State area greater sage-
grouse population occurs in the Mono province (Rowland et al. 2003, p.
63). This ecological province is part of the Great Basin, and on a
gross scale the ecological provinces that comprise this area are
characterized by basin and range topography. Basin and range topography
covers a large portion of the western United States and northern
Mexico. It is typified by a series of north-south-oriented mountain
ranges running parallel to each other, with arid valleys between the
mountains. Most of Nevada and eastern California comprise basin and
range topography with only slight variations in floristic patterns.
Hence, we do not consider Bi-State area greater sage-grouse to occur in
an ecological setting that is unique for the taxon.
(2) Evidence that its loss would result in a significant gap in the
range of the taxon. The estimated total extant range of greater sage-
grouse is 668,412 km\2\ (258,075 mi\2\) (Schroeder et al. 2004, p. 363)
compared to approximately 18,310 km\2\ (7,069 mi\2\) for the Bi-State
area sage-grouse (Bi-State Plan 2004). Bi-State area sage-grouse
therefore occupy about 3 percent of the total extant range of greater
sage-grouse. Loss of this population would not create a gap in the
remainder of the species range because the Bi-State population does not
provide for connectivity for other portions of the range. Therefore, we
conclude that loss of this population would not represent a significant
gap in the range of the species.
(3) Evidence that it is the only surviving natural occurrence of a
taxon that may be more abundant elsewhere as an introduced population
outside its historical range. Bi-State area greater sage-grouse are not
the only surviving occurrence of the taxon and represent a small
proportion of the total extant range of the species.
(4) Evidence that the discrete population segment differs markedly
from other populations of the species in its genetic characteristics.
Genetic analyses show the Bi-State area sage-grouse have a large number
of unique haplotypes not found elsewhere in the range of the species
(Benedict et al. 2003, p. 306; Oyler-McCance et al. 2005, p. 1300).
Benedict et al. (2003, p. 309) indicated that the preservation of
genetic diversity represented by this unique allelic composition is of
particular importance for conservation.
On the basis of the discussion presented above, we conclude the Bi-
State greater sage-grouse population meets the significance criterion
of our DPS Policy.
Conclusion of Distinct Population Segment Review
Based on the best scientific and commercial data available, as
described above, we find that under our DPS Policy, the Bi-State
greater sage-grouse population is discrete and significant to the
overall species. Because the Bi-State greater sage-grouse population is
both discrete and significant, we find that it is a distinct population
segment under our DPS Policy. We refer to this population segment as
the Bi-State DPS of the greater sage-grouse.
Conservation Status
Pursuant to the Act, as stated above, we announced our
determination that the petitions to list the Bi-State area population
of greater sage-grouse contained substantial information that the
action may be warranted. Having found the Bi-State population qualifies
as a DPS, we now must consider, based on the best available scientific
and commercial data whether the DPS warrants listing. We have evaluated
the conservation status of the Bi-State DPS of the greater sage-grouse
in order to make that determination. Our analysis follows below.
Life History Characteristics
Please see this section of the greater sage-grouse 12-month
petition finding (GSG finding) above for life history information.
Habitat Description and Characteristics
Please see this section of the GSG finding, above, for information
on sage-grouse habitat.
Distribution
The Bi-State DPS of the greater sage-grouse historically occurred
throughout most of Mono, eastern Alpine, and northern Inyo Counties,
California (Hall et al. 2008, p. 97), and portions of Carson City,
Douglas, Esmeralda, Lyon, and Mineral Counties, Nevada (Gullion and
Christensen 1957, pp. 131-132; Espinosa 2006a, pers. comm.). Although
the current range of the population in California was presumed reduced
from the historical range (Leach and Hensley, 1954, p. 386; Hall 1995,
p. 54; Schroeder et al. 2004, pp. 368-369), the extent of loss is not
well understood and there may, in fact, have been no net loss (Hall et
al. 2008, p. 96) in the California portion of the Bi-State area.
Gullion and Christensen (1957, pp. 131-132) reported that greater sage-
grouse occurred in Esmeralda, Mineral, Lyon, and Douglas Counties.
However, parts of Carson City County were likely part of the original
range of the species in Nevada and it is possible that greater sage-
grouse still persist there (Espinosa 2006a, pers. comm.). The extent of
the range loss in the Nevada portion of the Bi-State area not been
estimated (Stiver 2002, pers. comm.).
In 2001, the State of Nevada sponsored development of the Nevada
Sage-Grouse Conservation Strategy (Sage-Grouse Conservation Planning
Team 2001). This Strategy established Population Management Units
(PMUs) for Nevada and California as management tools for defining and
monitoring greater sage-grouse distribution (Sage-Grouse Conservation
Planning Team 2001, p. 31). The PMU boundaries are based on
aggregations of leks, greater sage-grouse seasonal habitats, and
greater sage-grouse telemetry data (Sage-Grouse Conservation Planning
Team 2001, p. 31). The PMUs that comprise the Bi-State planning area
are Pine Nut, Desert Creek-Fales, Mount Grant, Bodie, South Mono, and
White Mountains (Figure 4).
[[Page 13991]]
[GRAPHIC] [TIFF OMITTED] TP23MR10.003
Currently in the Bi-State area, sage-grouse leks occur in all of
the delineated PMUs, with the greatest concentration of leks occurring
in the Bodie and South Mono PMUs. Historically there were as many as
122 lek locations in the Bi-State area, although not all were active in
any given year. This number is likely inflated due to observer and
mapping error. The Nevada Department of Wildlife (NDOW) reports a total
of 89 known leks in the Bi-State area (NDOW 2008, p. 7; NDOW 2009,
unpublished data). Of these, approximately 39 are considered active and
approximately 30 appear to be core leks or occupied annually.
In the Pine Nut PMU, there are 10 known leks, 4 of which are
considered active. Only 1 or 2 appear to be core leks (occupied
annually) with the remainder considered satellite leks (active during
years of high bird abundance).
In the Desert Creek-Fales PMU, there are 19 known leks on the
Nevada portion consisting of 8 active leks and probably 4 core leks. In
California, on the Fales portion of this PMU, there are 6 known leks
consisting of 2 or 3 core leks and 3 satellite leks.
In the Mount Grant PMU, there are 12 known leks with 8 active
leks. Of the active leks, 2 to 4 appear to be annually attended. Survey
data are limited, and it is not known how many leks are active on an
annual basis versus in years of high bird abundance.
[[Page 13992]]
In the Bodie PMU, 29 leks have been mapped. Approximately 7 to
8 appear to be core leks, 6 to 12 appear to be satellite locations, and
the remainder are not well defined (i.e., satellites or changes in lek
focal activity, poorly mapped, one-time observations).
In the South Mono PMU there are 9 leks in the Long Valley area
near Mammoth Lakes, most of which are annually active. Additionally, 1
lek occurs in the Parker Meadows area south of Lee Vining, and 2 leks
occurred along Highway 120 at the base of Granite Mountain and in Adobe
Valley but these 2 leks may be extirpated.
In the White Mountains PMU 2 leks appear active in California
in the vicinity of the Mono and Inyo County line, and the NDOW reports
5 active leks in Esmeralda County.
Due to long-term and extensive survey efforts, it is unlikely that
new leks will be found in the Nevada or California portions of the Pine
Nut and Desert Creek-Fales PMUs or the Bodie and South Mono PMUs in
California (Espinosa 2006b, pers. comm.; Gardner 2006, pers. comm.). It
is possible that unknown leks exist in the Mount Grant PMU and the
Nevada and California portions of the White Mountains PMU, as these
PMUs are less accessible resulting in reduced survey effort (Espinosa
2006b, pers. comm.; Gardner 2006, pers. comm.).
Based on landownership, 46 percent of leks in the Bi-State area
occur on Bureau of Land Management (BLM) lands, 25 percent occur on
U.S. Forest Service (USFS) lands, 17 percent occur on private land, 7
percent occur on Los Angeles Department of Water and Power (LADWP)
lands, 4 percent occur on Department of Defense (DOD) lands, and 1
percent occur on State of California lands (Espinosa 2006c, pers.
comm.; Taylor 2006, pers. comm.). Of the 30-35 core leks in the Bi-
State area, only 3 are known to occur on private lands.
Population Trend and Abundance
In 2004, WAFWA conducted a partial population trend analysis for
the Bi-State area (Connelly et al. 2004, Chapter 6). The WAFWA
recognizes four populations of greater sage-grouse in the Bi-State area
but only two populations (North Mono Lake and South Mono Lake) had
sufficient data to warrant analysis (Connelly et al. 2004, pp. 6-60, 6-
61, 6-62). Essentially, the South Mono Lake population encompasses the
South Mono PMU, while the North Mono Lake population encompasses the
Bodie, Mount Grant, and Desert Creek-Fales PMUs. The authors reported
that the North Mono Lake population displayed a significant negative
trend from 1965 to 2003, and the South Mono Lake population displayed a
non-significant positive trend over this same period (Connelly et al.
2004, pp. 6-69, 6-70).
In 2008, WAFWA conducted a similar trend analysis on these two
populations using a different statistical method for the periods from
1965 to 2007, 1965 to 1985, and 1986 to 2007 (WAFWA 2008, Appendix D).
The 2008 WAFWA analysis reports the trend for the North Mono Lake
population, as measured by maximum male attendance at leks, was
negative from 1965 to 2007 and 1965 to 1985 but variable from 1986 to
2007, and suggests an increasing trend beginning in about 2000. WAFWA's
results for the South Mono Lake population suggest a negative trend
from 1965 to 2007, a stable trend from 1965 to 1985, and a variable
trend from 1986 to 2007, again suggesting a positive trend beginning
around 2000. These two populations do not encompass the entire Bi-State
area but do represent a large percentage of known leks. The two PMUs
excluded from this analysis were the Pine Nut and White Mountains,
which WAFWA delineates as separate populations that lacked sufficient
data for analysis.
A new analysis by Garton et al. (in press, pp. 36, 37), also
reports a decline in the North Mono Lake population from the 1965-1969
to 2000-2007 assessment periods, with no consistent long-term trend. In
the South Mono Lake population, Garton et al. (in press, pp. 37, 38)
report an increase in the 1965-1969 to 1985-1989 assessment periods but
a decline in the 1985-1989 to 2000-2007 assessment periods, with no
obvious trend. Garton et al. (in press, pp. 36, 38) report that the
estimated average annual rate of change for both of these populations
suggests that growth of these two populations has been, at times, both
positive and negative.
The CDFG and NDOW annually conduct greater sage-grouse lek counts
in the California and Nevada portions, respectively, of the Bi-State
area. These lek counts are used by the CDFG and NDOW to estimate
greater sage-grouse populations for each PMU in the Bi-State area. Low
and high population estimates are derived by combining a corrected
number of males detected on a lek, an assumed sex ratio of two females
to one male, and two lek detection rates (intended to capture the
uncertainty associated with finding leks). The lek detection rates vary
by PMU but range between 0.75 and 0.95.
Beginning in 2003, the CDFG and NDOW began using the same method to
estimate population numbers, and consequently, the most comparable
population estimates for the entire Bi-State area start in 2003. Prior
to 2003, Nevada survey efforts varied from year to year, with no data
for some years, and inconsistent survey methodology. The CDFG methods
for estimating populations of greater sage-grouse in California were
more consistent than NDOW's prior to 2003. However, using population
estimates for greater sage-grouse derived before 2003 could lead to
invalid and unjustified conclusions given the variation in the number
of leks surveyed, survey methodology, and population estimation
techniques between the NDOW and CDFG. Therefore, we are presenting
population numbers from 2003 to 2009. Population estimates derived from
spring lek counts are problematic due to unknown or uncontrollable
biases such as the true ratio of females to males or the percentage of
uncounted leks. We provide this information in order to place into
context what we consider to be a reasonable range as to the extent of
the population in the Bi-State area as well as to demonstrate the
apparent variability in annual estimates over the short term. For
reasons described above we caution against assigning too much certainty
to these results.
Spring population estimates are presented in Tables 11 and 12 for
the South Mono, Bodie, Mount Grant, and Desert Creek-Fales PMUs (CDFG
2009, unpublished data; NDOW 2009, unpublished data). They also include
population estimates for the Nevada portion of the Pine Nut PMU (NDOW
2009, unpublished data). However, they do not include population
estimates for the White Mountains PMU or the California portion of the
Pine Nut PMU. Due to the difficulty in accessing the White Mountains
PMU, no consistent surveys have been conducted and it appears that
birds are not present in the California portion of the Pine Nut PMU
(Gardner 2006, pers. comm.).
[[Page 13993]]
Table 11--Combined spring population estimates for Bi-State area greater
sage-grouse. (See text for citations.)
------------------------------------------------------------------------
Survey year Population estimate range
------------------------------------------------------------------------
2003 2,820 to 3,181
------------------------------------------------------------------------
2004 3,682 to 4,141
------------------------------------------------------------------------
2005 3,496 to 3,926
------------------------------------------------------------------------
2006 4,218 to 4,740
------------------------------------------------------------------------
2007 3,287 to 3,692
------------------------------------------------------------------------
2008 2,090 to 2,343
------------------------------------------------------------------------
2009 2,712 to 3,048
------------------------------------------------------------------------
Table 12--Population Management Unit (PMU) size, ownership and estimated suitable greater-sage-grouse habitat,
and estimated greater sage-grouse population for 2009. (See text for details and citations.)
----------------------------------------------------------------------------------------------------------------
Total Size acres Percent Federal Estimated Habitat Estimated
Population Management Unit (PMU) (ha) Land acres (ha) Population (2009)
----------------------------------------------------------------------------------------------------------------
Pine Nut 574,373 (232,441) 72 233,483 (94,488) 89-107
----------------------------------------------------------------------------------------------------------------
Desert Creek-Fales 567,992 (229,859) 88 191,985 (77,694) 512-575
----------------------------------------------------------------------------------------------------------------
Mount Grant 699,079 (282,908) 90 254,961 (103,180) 376-427
----------------------------------------------------------------------------------------------------------------
Bodie 349,630 (141,491) 74 183,916 (74,428) 829-927
----------------------------------------------------------------------------------------------------------------
South Mono 579,483 (234,509) 88 280,492 (113,512) 906-1,012
----------------------------------------------------------------------------------------------------------------
White Mountains 1,753,875 97 418,056 (169,182) NA
(709,771)
----------------------------------------------------------------------------------------------------------------
As shown in Table 12, Federal lands comprise the majority of the
area within PMUs. Although other land ownership is small in comparison,
these other lands contain important habitat for greater sage-grouse
life cycle requirements. In particular, mesic areas that provide
important brood rearing habitat are often on private lands.
Movement, Habitat Use, Nest Success, and Survival
Casazza et al. (2009, pp. 1-49) conducted a 3-year study on greater
sage-grouse movements in the Bi-State area. The researchers radio-
marked 145 birds, including 104 females and 41 males, in Mono County
within the Desert Creek-Fales, Bodie, White Mountains, and South Mono
PMUs (Casazza et al. 2009, p. 6). The greatest distance moved by radio-
marked birds between any two points is as follows: 29 percent moved
from 0 to 8 km (0 to 5 mi); 41 percent moved from 8 to 16 km (5 to 10
mi); 25 percent moved from 16 to 24 km (10 to 15 mi); 4 percent moved
from 24 to 32 km (15 to 20 mi); and 1 percent moved greater than 32 km
(20 mi).
Female greater sage-grouse home range size ranged from 2.3 to 137.1
km\2\ (0.9 to 52.9 mi\2\), with a mean home range size of 38.6 km\2\
(14.9 mi\2\) (Overton 2006, unpublished data). Male greater sage-grouse
home range size ranged from 6.1 to 245.7 km\2\ (2.3 to 94.9 mi\2\) with
a mean home range size of 62.9 km\2\ (24.1 mi\2\) (Overton 2006,
unpublished data). Annual home ranges were largest in the Bodie PMU and
smallest in the Parker Meadows area of the South Mono PMU and the
California portion of the Desert Creek-Fales PMU.
The data from more than 7,000 telemetry locations, representing the
145 individuals indicate movement between populations in the Bi-State
area is limited. No birds caught within the White Mountains, South
Mono, or Desert Creek-Fales PMUs made movements outside their
respective PMUs of capture. Previously, the NDOW tracked a female
greater sage-grouse radio-marked near Sweetwater Summit in the Nevada
portion of the Desert Creek-Fales PMU to Big Flat in the northern
portion of the Bodie PMU, suggesting possible interaction between these
PMUs. Also, some birds caught in the Bodie PMU made seasonal movements
on the order of 8 to 24 km (5 to 15 mi) east into Nevada and the
adjacent Mount Grant PMU. Within the Bi-State area some known bird
movements would be classified as migratory, but the majority of radio-
marked individuals have not shown movements large enough to be
characterized as migratory (Casazza et al. 2009, p. 8).
In association with Casazza et al. (2009), Kolada (2007) conducted
a study examining nest site selection and nest survival of greater
sage-grouse in Mono County, These greater sage-grouse selected nest
sites high in shrub cover (42 percent on average), and these shrubs
were often species other than sagebrush (i.e., bitterbrush (Purshia
tridentata)) (Kolada 2007, p. 18). The reported amount of shrub cover
was not outside the normal range found in other studies (Connelly et
al. 2000a, p. 970). However, there was a large contribution of non-
sagebrush shrubs to greater sage-grouse nesting habitat in Mono County.
There was no evidence that greater sage-grouse hens were selecting for
nest sites with greater residual grass cover or height as compared to
random sites. Overall nest success among birds in Mono County during
the 3-year study (2003-2005) appears to be among the highest of any
population rangewide (Kolada 2007, p. 70). However, nest
[[Page 13994]]
success in Long Valley (South Mono PMU) was substantially lower than
for either the Bodie or Desert Creek-Fales PMUs.
Also in association with Casazza et al. (2009), Farinha et al.
(2008, unpublished data) found that survival of adults was lowest in
the northern Bi-State area and highest in Long Valley. Near Sonora
Junction, California (Desert Creek-Fales PMU) and in the Bodie Hills
(Bodie PMU), adult survival was 4 and 18 percent, respectively.
Sedinger et al. (unpublished data, p. 12) derived a similar adult
survival estimate (16 percent) for an immediately adjacent area in
Nevada. Survival estimates at these three locations are unusually low
(Sedinger et al. unpublished data, p. 12). In Long Valley, Farinha et
al. (2008, unpublished data) estimated adult survival at 53 percent,
which is more consistent with annual survival estimates reported in
other portions of the species' range.
Summary of Factors Affecting the Bi-State DPS of the Greater Sage-
Grouse
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
at 50 CFR part 424, set forth procedures for adding species to the
federal Lists of Endangered and Threatened Wildlife and Plants. In
making this finding, we summarize below information regarding the
status and threats to the Bi-State DPS of the greater sage-grouse in
relation to the five factors provided in section 4(a)(1) of the Act.
Under section (4) of the Act, we may determine a species to be
endangered or threatened on the basis of any of the following five
factors: (A) Present or threatened destruction, modification, or
curtailment of habitat or range; (B) overutilization for commercial,
recreational, scientific, or educational purposes; (C) disease or
predation; (D) inadequacy of existing regulatory mechanisms; or (E)
other natural or manmade factors affecting its continued existence. We
evaluated whether threats to the Bi-State area greater sage-grouse DPS
may affect its survival. Our evaluation of threats is based on
information provided in the petitions, available in our files, and
other sources considered to be the best scientific and commercial
information available including published and unpublished studies and
reports.
Our understanding of the biology, ecology, and habitat associations
of the Bi-State DPS of the greater sage-grouse, and the potential
effects of perturbations such as disease, urbanization, and
infrastructure development on this population, is based primarily on
research conducted across the range of the entire greater sage-grouse
species. The available information indicates that the members of the
species have similar physiological and behavioral characteristics, and
consequently similar habitat associations. We believe the potential
effects of specific stressors on the Bi-State DPS of the greater sage-
grouse are the same as those described in the GSG finding, above. To
avoid redundancy, the descriptions of these effects are omitted below
and further detail and citations may be found in the corresponding
analysis in the GSG finding, above.
The range of the Bi-State DPS of the greater sage-grouse is roughly
3 percent of the area occupied by the entire greater sage-grouse
species, and the relative impact of effects caused by specific threats
may be greater at this smaller scale. We have considered these
differences of scale in our analysis and our subsequent discussion is
focused on the degree to which each threat influences the Bi-State DPS
of the greater sage-grouse. Individual threats described within Factors
A through E below are not all present across the entire Bi-State area.
However, the influence of each threat on specific populations may
influence the resiliency and redundancy of the entire Bi-State greater
sage-grouse population.
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
Urbanization
Changing land uses have and continue to occur in the Bi-State area.
Where traditional private land use was primarily farming and ranching
operations, today, some of these lands are being sold and converted to
low-density residential housing developments. About 8 percent of the
land base in the Bi-State area is privately owned. A 2004 threat
analysis recognized urban expansion as a risk to greater sage-grouse in
the Pine Nut, Desert Creek-Fales, Bodie, and South Mono PMUs (Bi-State
Plan 2004, pp. 24, 47, 88, 169). The CDFG reports that private lands
have been sold and one parcel was recently developed on Burcham Flat
within the Desert Creek-Fales PMU (CDFG 2006). Additionally, a planned
subdivision of a 48 ha (120 ac) parcel that is in close proximity to
the Burcham Flat lek, 1 of 3 remaining leks in the California portion
of the Desert Creek-Fales PMU, is currently under review by the County
of Mono, California. The subdivision would replace a single ranch
operation with three private residences.
Sagehen (16.2 ha (40 ac)) and Gaspipe (16.2 ha (40 ac)) Meadows
located in the South Mono PMU have recently been affected by
development. Also, Sinnamon (~485 ha, ~1,200 ac) and Upper Summers
Meadows (~1,214 ha; ~3,000 ac) located in the Bodie PMU are currently
for sale (Taylor 2008, pers. comm.). Each of these private parcels is
important to greater sage-grouse because of the summer brood-rearing
habitat they provide (Taylor 2008, pers. comm.). The NDOW is concerned
that the urbanization or the division of larger tracts of private lands
into smaller ranchettes will adversely affect greater sage-grouse
habitat in the Nevada portion of the Pine Nut and Desert Creek-Fales
PMUs (NDOW 2006, p. 4). The NDOW reported that expansions of Minden,
Gardnerville, and Carson City, Nevada, are encroaching into the Pine
Nut Range (within the Pine Nut PMU) and that housing development in
Smith Valley and near Wellington, Nevada, has fragmented and diminished
greater sage-grouse habitats in the north portion of the Desert Creek-
Fales PMU (NDOW 2006, p. 4).
Development of private lands is known to impact greater sage-grouse
habitat (Connelly et al. 2004, pp. 7-25, 7-26), and federal and state
agencies may actively work to purchase parcels important for greater
sage-grouse conservation. Recently, the State of California purchased a
470 ha (1,160 ac) parcel in the Desert Creek-Fales PMU comprising the
largest contiguous private land parcel in the California portion of the
PMU.
When private lands adjacent to public lands are developed, there
can be impacts to greater sage-grouse on the public lands.
Approximately 89 percent of the land contained within the Bi-State area
is federally managed land, primarily by the USFS and BLM. The BLM and
USFS manage public lands under federal laws that provide for multiple-
use management, which allows a number of actions that are either
detrimental or beneficial to sage-grouse (Bi-State Plan 2004). The Bi-
State Plan (2004, pp. 24, 88) reported within the Pine Nut and Bodie
PMUs, habitat loss and fragmentation associated with land use change
and development is not restricted to private lands. Rights-of-way (ROW)
across public lands for roads, utility lines, sewage treatment plants,
and other public purposes are frequently granted to support development
activities on adjacent private parcels.
Based on location data from radio-marked birds in the Desert Creek-
Fales, Bodie, and South Mono PMUs, greater sage-grouse home ranges
consist of a
[[Page 13995]]
combination of public and privately owned lands (Casazza 2009, p. 9).
In the Desert Creek-Fales PMU, use of private lands was most pronounced
near Burcham and Wheeler Flats. Home ranges of these individuals
encompassed between 10 and 15 percent private lands, depending on the
season (Casazza et al. 2009, p. 19). In the Bodie PMU radio-marked
birds were found to use private lands between 10 and 20 percent of the
time, with use most pronounced during the summer and winter months
(Casazza 2009, p. 27). In the South Mono and White Mountains PMUs, use
of private lands was greatly restricted. We have limited quantitative
data for birds breeding in the Nevada portion of the Bi-State area.
However, some greater sage-grouse breeding in the Bodie PMU moved to
wintering habitat on private land in Nevada on the adjacent Mount Grant
PMU. Also, private lands in the Nevada portion of the Desert Creek-
Fales PMU and the Mount Grant PMU are used by sage-grouse throughout
the year, especially during the late summer brood-rearing period
(Espinosa 2008, pers. comm.).
The Town of Mammoth Lakes, California, located in the southern
extent of the Bi-State planning area recently adopted measures that
will allow for more development on private lands (Town of Mammoth Lakes
General Plan 2007). Increased indirect effects to greater sage-grouse
habitat are expected due increases in the human population in the area.
The proposed expansion of the Mammoth Yosemite Airport is located
in occupied greater sage-grouse habitat within the South Mono PMU.
Approximately 1.6 ha (4 ac) of land immediately surrounding the airport
is zoned for development. Also, the Federal Aviation Administration
(FAA) recently resumed regional commercial air service at the Airport
with two winter flights per day beginning in 2008 and potentially
increasing to a maximum of eight winter flights per day by 2011 (FAA
2008, ES-1). The Mammoth Yosemite Airport formerly had regional
commercial air service from 1970 to the mid-1990's (FAA 2008, p. 1-5),
and it currently supports about 400 flights per month of primarily
single-engine, private aircraft (Town of Mammoth Lakes 2005, p. 4-204).
All greater sage-grouse in the Long Valley portion of the South Mono
PMU occur in close proximity to the Airport and have been exposed to
commercial air traffic in the past, and are currently exposed to
private air traffic. Effects of reinstating commercial air service at
the Mammoth Yosemite Airport on greater sage-grouse are unknown as the
level of commercial flight traffic these birds may be exposed to is
undetermined as is the impact this exposure will have on population
dynamics.
The Benton Crossing landfill in Mono County is located north of
Crowley Lake in Long Valley (South Mono PMU) on a site leased from the
LADWP. Common ravens (Corvus corax) and California gulls (Larus
californicus) are known to heavily use the facility (Coates 2008, pers.
comm.), although no specific surveys of either species' abundance have
been conducted. The influence these known predators have on the
population dynamics of the South Mono PMU is not known. However, Kolada
(2007, p. 66) reported that nest success in Long Valley was
significantly lower in comparison to other populations within the Bi-
State planning area. This result may be attributable to the increased
avian predators subsidized by landfill operations (Casazza 2008, pers.
comm.).
Summary: Urbanization
Development of private lands for housing and the associated
infrastructure within the Bi-State area is resulting in the destruction
and modification of habitat of the Bi-State area greater sage-grouse
DPS. The threat of development is greatest in the Pine Nut, Desert
Creek-Fales, and Bodie PMUs, where development is, and will likely
continue to impact Bi-State area greater sage-grouse DPS use of
specific seasonal sites. The small private holdings in the Bi-State
area are typically associated with mesic meadow or spring habitats that
play an important role in greater sage-grouse life history. Greater
sage-grouse display strong site fidelity to traditional seasonal
habitats and loss of specific sites can have pronounced population
impacts. The influence of land development on the population dynamics
of greater sage-grouse in the Bi-State area is greater than a simple
measure of spatial extent. As noted above, resumption of commercial air
service at the Mammoth Yosemite Airport, combined with the construction
of an adjacent business park, will likely affect greater sage-grouse in
the South Mono PMU through increasing aircraft and human activity in or
near sage-grouse habitat.
Development of public and private lands for a variety of purposes,
including residential homes and ROWs to support associated
infrastructure can negatively affect sage-grouse and their habitat, and
while these threats may not be universal, localized areas of impacts
are anticipated. Based on the data available, direct and indirect
effects of urbanization have exerted and will continue to exert a
negative influence in specific portions of greater sage-grouse range in
the Bi-State area. This is already especially apparent in the northern
portion of the range of the Bi-State DPS of the greater sage-grouse, in
the Pine Nut, Desert Creek-Fales, and Bodie PMUs (NDOW 2006, p. 4; Bi-
State Plan 2004, pp. 24, 88).
Infrastructure - Fences, Powerlines, and Roads
Fences are considered a risk to greater sage-grouse in all Bi-State
PMUs (Bi-State Plan 2004, pp. 54, 80, 120, 124, 169). As stated in the
December 19, 2006, 90-day finding (71 FR 76058), the BLM Bishop Field
Office reported increased greater sage-grouse mortality and decreased
use of leks when fences were in close proximity. Known instances of
collision, and the potential to fragment and degrade habitat quality by
providing movement pathways and perching substrates for invasive
species and predators have been cited.
Fences can also provide a valuable rangeland management tool. If
properly sited and designed, fencing may ultimately improve habitat
conditions for greater sage-grouse. Near several leks in the Long
Valley area of the South Mono PMU, the BLM and LADWP are currently
using ``let down'' fences as a means of managing cattle. This design
utilizes permanent fence posts but allows the horizontal wire strands
to be effectively removed (let down) during the greater sage-grouse
breeding season or when cattle are not present. While this method does
not ameliorate all negative aspects of fence presence such as perches
for avian predators, it does reduce the likelihood of collisions.
Currently, data on the total extent (length and distribution) of
existing fences and the amount of new fences being constructed are not
available for the Bi-State area.
Powerlines occur in all Bi-State PMUs and are a known threat to the
greater sage-grouse, but the degree of effect varies by location. In
the Pine Nut PMU, powerlines border the North Pine Nut lek complex on
two sides (Bi-State Plan 2004, p. 28). An additional line segment to
the northwest of this complex is currently undergoing review by the BLM
Carson City District. If this additional line is approved, powerlines
will surround the greater sage-grouse habitat in the area. Of the four
leks considered active in the area, the distance between the leks and
the powerlines ranges from approximately 1.2 to 2.9 km (0.74 to 1.8
mi). Additionally, one line currently bisects the relatively limited
nesting habitat in
[[Page 13996]]
the area. Proximity to powerlines is negatively associated with greater
sage-grouse habitat use, with avoidance of otherwise suitable breeding
habitat (as indicated by the location of active leks), which may be the
result of predator avoidance (e.g., ravens and raptors) (Bi-State Plan
2004, p. 81; and see Powerlines discussion under Factor A in the GSG
finding above).
In the Desert Creek-Fales PMU, powerlines are one of several types
of infrastructure development that impact greater sage-grouse through
displacement and habitat fragmentation (Bi-State Plan 2004, p. 54).
Recent declines in populations near Burcham and Wheeler Flats in the
California portion of the Desert Creek-Fales PMU may be related to
construction of powerlines and associated land use activities (Bi-State
Plan 2004, p. 54). This area continues to see urban development which
will likely require additional distribution lines. In the Bodie PMU,
utility lines are a current and future threat that affects multiple
sites (Bi-State Plan 2004, p. 81). In northern California, utility
lines have a negative effect on lek attendance and strutting activity.
Radio-tagged greater sage-grouse loss to avian predation increased as
the distance to utility lines decreased (Bi-State Plan 2004, p. 81).
Common ravens are a capable nest predator and often nest on power poles
or are found in association with roads. The Bi-State Plan also
identifies numerous small-distribution utility lines in the Bodie PMU
that are likely negatively affecting greater sage-grouse. The plan
references the expected development of new lines to service private
property developments. The BLM Bishop Field Office reported reduced
activity at one lek adjacent to a recently developed utility line and
suggested this may have been influenced by the development (Bi-State
Plan 2004, p. 81). Since 2004, however, numbers at this lek have
rebounded. Currently, there are no high-voltage utility lines in the
Bodie PMU, nor are there any designated corridors for this use in
existing land use plans (Bi-State Plan 2004, p. 82).
A high-voltage powerline currently fragments the Mount Grant PMU
from north to south, with two to three additional smaller distribution
lines extending from Hawthorne, Nevada, west to the California border.
The larger north-south trending powerline is sited in a corridor that
was recently adopted as part of the West-wide Energy Corridor
Programmatic EIS (BLM/USFS 2009), thus future development of this
corridor is anticipated. There are two leks that likely represent a
single complex in proximity to this line segment that have been
sporadically active over recent years. Whether this variation in active
use is due to the powerline is not clear. Additionally, there is strong
potential for geothermal energy development in the Mount Grant PMU that
will require additional distribution lines to tie into the existing
electrical grid (see Renewable Energy Development below; RETAAC 2007).
Of significant concern will be additional distribution lines in
proximity to the historic mining district of Aurora, Nevada, which
supports the largest lek in the Mount Grant PMU and occurs about 2.5 km
(1.5 mi) from the main north-south line.
The Bi-State Plan (2004, p. 169) mentions three transmission lines
in the South Mono PMU that may be impacting birds in the area on a year
round basis including three leks that are in proximity to existing
utility lines. Future geothermal development may also result in
expansion of transmission lines in the South Mono PMU (Bi-State Plan
2004, p. 169). Threats posed by powerlines to the White Mountains PMU
are not currently imminent, although future development is possible.
An extensive road network occurs throughout the Bi-State area. The
type of road varies from paved, multilane highways to rough jeep trails
but the majority of road miles are unpaved, dirt two-track roads.
Traffic volume varies significantly, as does individual population
exposure. For a comprehensive discussion of the effects of roads on
greater sage-grouse see Roads under Factor A in the GSG finding above.
In the Desert Creek-Fales PMU, roads are a risk to greater sage-grouse
(Bi-State Plan 2004, p. 54). All leks in this PMU are in close
proximity to dirt two-track roads. Seven of eight consistently occupied
leks in recent years are in relatively close proximity (< 2.5 km (1.5
mi)) to well- traveled highways. Although abundant, roads were not
presented as a specific risk factor for the Pine Nut, Bodie, or Mount
Grant PMUs during the development of their respective risk assessments
(Bi-State Plan 2004). Large portions of these PMUs are not accessible,
due to heavy winter snow until early summer after the completion of the
breeding season and many of the roads are not frequently traveled.
However, several leks in the Bodie PMU are in proximity to well-
maintained and traveled roads.
In the South Mono PMU, roads are recognized as a risk factor that
affects greater sage-grouse habitat and populations (Bi-State Plan
2004, p. 169). A variety of roads in this area have access to many
significant lek sites. In Long Valley, lek sites are accessible via
well maintained gravel roads. Recreational use of these areas is high
and road traffic is substantial. Two lek sites that were in close
proximity (< 300 m (1,000 ft)) to Highway 120 are thought to be
extirpated although the exact cause of extirpation is unknown. Roads in
the White Mountains PMU may negatively impact greater sage-grouse
populations and their habitats, and construction of new roads in this
PMU will fragment occupied or potential habitat for the species (Bi-
State Plan 2004, pp. 120, 124).
Although greater sage-grouse have been killed due to vehicle
collisions in the Bi-State area (Wiechmann 2008, p. 3), the greater
threat with respect to roads is their influence on predator movement,
invasion by nonnative annual grasses, and human disturbance. Currently
in the Bi-State area, all federal lands except those managed by the
BLM's Carson City District Office have restrictions limiting vehicular
travel to designated routes. The lands where these restrictions apply
account for roughly 1.6 million ha (4 million ac) or 86 percent of the
land base in the Bi-State area. Both the Inyo and Humboldt-Toiyabe
National Forests have recently mapped existing roads and trails on
Forest Lands in the Bi-State area as part of a USFS Travel Management
planning effort including identification of designated routes (Inyo
National Forest 2009; Humboldt-Toiyabe National Forest 2009). These
planning efforts will most directly influence the South Mono, Desert
Creek-Fales, and Mount Grant PMUs; however, the degree to which they
will influence greater sage-grouse populations is unclear. While the
planning effort of the Inyo National Forest has, and the planning
effort of the Humboldt-Toiyabe National Forest will likely add many
miles of unauthorized routes to the National Forest System, these
routes have already been in use for decades and any future negative
impacts will be the result of an increase in use of these routes.
Starting in 2005, the BLM's Bishop Field Office implemented
seasonal closures of several roads in proximity to three lek complexes
in the Long Valley area of the South Mono PMU during the spring
breeding season as part of a greater sage-grouse management strategy
(BLM 2005c, p. 3). The Field Office is also rehabilitating several
miles of redundant routes to consolidate use and minimize habitat
degradation and disturbance for these same lek complexes.
[[Page 13997]]
Summary: Infrastructure - Fences, Powerlines, and Roads
Existing fences, powerlines, and roads fragment and degrade greater
sage-grouse habitat, and contribute to direct mortality through
collisions. Additionally, new fences, powerlines, and roads increase
predators and invasive plants that increase fire risk and or displace
native sagebrush vegetation. In the Bi-State area, all of these linear
features adversely affect each of the PMUs both directly and indirectly
to varying degrees. However, we do not have consistent and comparable
information on miles of existing or new fences, powerlines and roads,
or densities of these features within PMUs for the Bi-State area as a
whole. Wisdom et al. (in press, p. 58) reported that across the entire
range of the greater sage-grouse species, the mean distance to highways
and transmission lines for extirpated populations was approximately 5
km (3.1 mi) or less. In the Bi-State area between 35 and 45 percent of
annually occupied leks, which are indicative of the presence of nesting
habitat, are within this distance to state or federal highways and
between 40 and 50 percent are within this distance to existing
transmission lines.
Lek counts suggest that greater sage-grouse populations in Long
Valley, and to a lesser degree Bodie Hills, have been relatively stable
over the past 15 years. The remaining populations in the Bi-State area
appear considerably less stable. Research on adult and yearling
survival suggests that annual survival is relatively low in the
northern half of the Bi-State area (Farinha 2008, unpublished data).
Annual survival was lowest in birds captured in association with the
Wheeler and Burcham Flat leks in the California portion of the Desert
Creek-Fales PMU, an area in very close proximity to Highway 395 and
several transmission lines. Research conducted on nest success,
however, shows an opposite trend from that of adult survival, with
overall nest success relatively high in the northern half of the Bi-
State area and lower in the southern half (Kolada 2007, p. 52). In Long
Valley, where nest success was lowest, the combination of linear
features (infrastructure) and an increased food source (Benton Crossing
landfill) for avian predators may be influencing nest survival. Given
current and future development (based on known energy resources), the
Mount Grant, Desert Creek-Fales, Pine Nut, and South Mono PMUs are
likely to be the most directly influenced by new powerlines and
associated infrastructure.
Greater sage-grouse in the Bi-State area have been affected by
roads and associated human disturbance for many years. The geographic
extent, density, type, and frequency of disturbance have changed over
time, and the impact has likely increased with the proliferation of
off-highway vehicles. There are no indications that the increasing
trend of these activities will diminish in the near future.
Mining
Mineral extraction has a long history throughout the Bi-State area.
Currently, the PMUs with the greatest exposure are Bodie, Mount Grant,
Pine Nut, and South Mono (Bi-State Plan 2004, pp. 89, 137, 178).
Although mining represents a year round risk to greater sage-grouse,
direct loss of key seasonal habitats or population disturbances during
critical seasonal periods are of greatest impact. In the Bodie PMU,
mining impacts to the ecological conditions were most pronounced in the
late 1800's and early 1900's when as many as 10,000 people inhabited
the area. The area is still open to mineral development, and
exploration is likely to continue into the future (Bi-State Plan 2004,
pp. 89-90). In the Bodie Hills, current mining operations are
restricted to small-scale gold and silver exploration and sand and
gravel extraction activities with limited impacts on greater sage-
grouse (Bi-State Plan 2004, p. 90). An exploratory drilling operation
is currently authorized in the Bodie Hills near the historic Paramount
Mine, approximately 8 km (5 mi) north of Bodie, California. The
proposed action may influence movement and use of important seasonal
habitats near Big Flat. If subsequent development occurs, restricted
use of or movement through this area will adversely influence
connectivity between the Bodie and Mount Grant PMUs.
The Mount Grant and Pine Nut PMUs also have a long history of
mining activity. Activity in the Mount Grant PMU has typically
consisted of open pit mining. Two open pit mines exist, one of which is
currently active. It is likely that mining will continue and may
increase during periods when prices for precious metals are high,
negatively effecting the sage-grouse populations in those areas. Mining
in the Mount Grant PMU is largely concentrated around the Aurora
historic mining district. This area contains the largest remaining lek
in the PMU, which is located on private land. In the Pine Nut PMU, most
mining activity is confined in woodland habitat but there is some
overlap with sage-grouse habitats.
Summary: Mining
The effect of mining is not evenly distributed throughout the Bi-
State area. It is greatest in the Mount Grant and Bodie PMUs where
mining impacts to habitat may decrease the persistence of greater sage-
grouse in the Mount Grant PMU Aurora lek complex area. This area
represents a significant stronghold for the Mount Grant PMU and serves
as a potential connection between breeding populations in the Bodie
Hills to the west with breeding populations occurring further east in
the Wassuk Range located on the eastern edge of the Mount Grant PMU.
Further mineral extraction in either of these PMUs will negatively
influence the spatial extent of the breeding population occurring in
the Bodie Hills and the long term persistence of these populations.
Energy Development
Although energy development and the associated infrastructure was
identified as a risk for greater sage-grouse occurring in the Bi-State
area (Bi-State Plan 2004, pp. 30, 178), the risk assessment preceded
the current heightened interest in renewable energy and underestimated
the threats to the species. Several locations in the Bi-State area have
suitable wind resources, but currently only the Pine Nut Mountains have
active leases that overlap sage-grouse distribution. Approximately
3,696 ha (9,135 ac) have been leased from the BLM Carson City District
and are being evaluated for wind development. The areas under lease are
on the main ridgeline of the Pine Nut Mountains extending from Sunrise
Pass near the Lyon and Douglas County line south to the Mount Siegel
area. The area is a mix of shrub and woodland habitats containing year-
round greater sage-grouse habitat. The ridgeline occurs between the
north and south greater sage-grouse populations in the Pine Nut PMU.
The area was recently designated as a renewable energy ``wind zone'' by
Nevada Governor Jim Gibbons' Renewable Energy Transmission Access
Advisory Committee (RETAAC; RETAAC 2007, Figure 2). Development of the
Pine Nut area will have a significant impact on the connectivity within
this small population and greatly restrict access to nesting and
brooding habitat. Additional areas located in sage-grouse habitat may
have suitable wind resources and could be developed in the future.
In the South Mono PMU there are two geothermal plants located on
private land immediately east of U.S. 395 at
[[Page 13998]]
Casa Diablo. These are the only operating geothermal plants in the Bi-
State area. Within the South Mono PMU about 3,884 ha (9,600 ac) are
under geothermal lease. The leased areas are located to the west of
U.S. 395 and immediately north of Highway 203 and largely outside of
occupied sage-grouse habitat.
Within the Desert Creek-Fales PMU, about 2,071 ha (5,120 ac) on the
north end of the Pine Grove Hills near Mount Etna are leased for
geothermal development. The leases in this area are valid through 2017.
Several locations within the Mount Grant PMU are also under current
leases and several more areas are currently proposed for leasing. Based
on location and vegetation community, two of the leased areas in the
Mount Grant PMU are of great importance to sage-grouse. Four sections
(1,035 ha, 2,560 ac) are leased approximately 1.6-4.8 km (1-3 mi)
southeast of the confluence between Rough Creek and the East Walker
River near the Lyon and Mineral County line on lands managed by the
USFS. This area is considered year-round greater sage-grouse habitat
with from one to three active leks in proximity. Additionally,
approximately 13 sections (3,366 ha, 8,320 ac) are leased around the
Aurora historic mining district near the Nevada and California border.
Much of this area is dominated by pinyon-juniper woodlands, but at
least three sections (776 ha, 1,920 ac) contain sagebrush communities
and there is one known lek in close proximity. The leased sections
within the Desert Creek-Fales and Mount Grant PMUs also fall within the
boundary delineated for geothermal development proposed by RETAAC
(RETAAC 2007, Figure 2).
Summary: Energy Development
The likelihood of renewable energy facility development in the Bi-
State area is high. There is strong support for energy diversification
in both Nevada and California, and the energy industry considers the
available resources in the area to warrant investment (RETAAC 2007, p.
8). Greater sage-grouse habitat in the Pine Nut and Mount Grant PMUs
will likely be most affected by facility and infrastructure
development. Given this anticipated development, additional
fragmentation and isolation as well as some degree of range contraction
will occur that will significantly affect the Pine Nut and Mount Grant
PMUs. Renewable energy development is not evenly distributed across the
entire Bi-State area, but it will likely be a significant threat to
populations in the Pine Nut and Mount Grant PMUs.
Grazing
In the Bi-State area, all PMUs are subject to livestock grazing
with the majority of ``public'' allotments allocated to cattle and
sheep (Bi-State Plan 2004). Determining how grazing impacts greater
sage-grouse habitat and populations is complicated. There are data to
support both beneficial and detrimental aspects of grazing (Klebenow
1981, p. 122; Beck and Mitchell 2000, p. 993), suggesting that the risk
of livestock grazing to greater sage-grouse is dependent on site-
specific management.
Kolada (2007, p. 52) reports nest success of greater sage-grouse in
the Bi-State area on average to be as high as any results reported
across the range of the species. However, nest success is varied among
PMUs, and residual grass cover did not appear to be as significant a
factor to nest success as in other western U.S. locations. These
findings suggest that grazing in the Bi-State area may not be strongly
influencing this portion of the bird's life history.
Important mesic meadow sites are relatively limited outside of Long
Valley and the South Mono PMU, especially north of Mono Lake (Bi-State
Plan 2004, pp. 17, 65, 130). This limitation may influence greater
sage-grouse population growth rates. Although most of the grazed lands
in the Bi-State area are managed by the BLM and USFS under rangeland
management practices and are guided by agency land use plans, much of
the suitable mesic habitats are located on private lands. Given their
private ownership assessing the condition of these sites is difficult
and conditions are not well known. Although there are federal grazing
allotments that are exhibiting adverse impacts from livestock grazing,
such as the Churchill Allotment in the Pine Nut PMU (Axtell 2008, pers.
comm.), most allotments in the Bi-State area are classified as being in
fair to good condition (Axtell 2008, pers. comm.; Murphy 2008, pers.
comm.; Nelson 2008, pers. comm.). We have no information indicating how
allotment condition classifications used by the BLM and USFS correlate
with greater sage-grouse population health.
Feral horses are present in the Bi-State area. Connelly et al.
(2004, pp. 7-36-7-37) stated that areas occupied by horses have lower
grass, shrub, and total vegetative cover and that horse alteration of
spring or other mesic areas may be a concern with regard to greater
sage-grouse brood rearing. The most significant impact from feral
horses has occurred in the Mount Grant and Pine Nut PMUs (Axtell 2008,
pers. comm.). The Bodie PMU has also been impacted by feral horses and
these animals pose a risk of disturbance to the 7-Troughs lek
population (Bi-State Plan 2004, pp. 86-87). The intent of the agencies
involved is to maintain horse numbers at or below those established for
the herd management areas (HMA) and wild horse territories (WHT). In
2003, the BLM captured and removed 26 horses from the Powell Mountain
WHT located in the Mount Grant PMU and 7 horses from the Bodie PMU.
Currently there are relatively low numbers of horses (10 to 20) in the
Bodie PMU. The Bodie Hills have no defined HMA/WHT but the horses
present are likely coming from the Powell Mountain WHT located in the
Mount Grant PMU (Bi-State Plan 2004, pp. 86-87). In 2007, the USFS took
an additional 87 horses off the Powell Mountain WHT (Murphy 2008, pers.
comm.). The herd management level set for the Powell Mountain WHT is 35
individuals. Although management of feral horse populations is an
ongoing issue, local land managers consider it to be controllable given
sufficient funding and public support.
Summary: Grazing
There are localized areas of habitat degradation attributable to
grazing that indirectly and cumulatively affect greater sage-grouse.
Overall population estimates, while variable from year-to-year, show no
discernable trend attributable to grazing. The impact on ecosystems by
different ungulate taxa may have a combined negative influence on
greater sage-grouse habitats (Beever and Aldridge in press, p. 20).
Cattle, horses, mule deer, and antelope each use the sagebrush
ecosystem somewhat differently and the combination of multiple species
may produce a different result than simply more of a single species.
Greater sage-grouse habitat in the Pine Nut PMU, as well as limited
portions of the Bodie PMU, is affected by grazing management practices
and has a negative effect on sage-grouse in those areas. Overall, the
available data do not provide evidence that grazing by domestic or
feral animals is a major impact to habitat of greater sage-grouse
throughout the entire Bi-State area. However, the loss or degradation
of habitat due to grazing contributes to the risk of extirpation of
some local populations, which in turn contributes to increased risk to
the persistence of the Bi-State DPS.
Fire
As discussed above, in the GSG finding, changes in the fire ecology
that result in an altered wildfire regime are a present and future risk
in all PMUs in
[[Page 13999]]
the Bi-State area (Bi-State Plan 2004). A reduction in fire occurrence
has facilitated the expansion of woodlands into montane sagebrush
communities. In the Pine Nut and Desert Creek-Fales PMUs this has
resulted in a loss of sagebrush habitat (Bi-State Plan 2004, pp. 20,
39), while in other locations such as the Bodie and Mount Grant PMUs
the most significant impact of conifer expansion is the additional
fragmentation of sage-grouse habitat and isolation of the greater sage-
grouse populations (Bi-State Plan 2004, pp. 95-96, 133).
Invasion by annual grasses (e.g., Bromus tectorum) can lead to a
shortening of the fire frequency that is difficult to reverse. Often
invasive species become established or become apparent only following a
fire or similar disturbance event. In the Bi-State area, there has been
little recent fire activity (Finn et al. 2004, http://wildfire.cr.usgs.gov/firehistory/data.html). One exception is in the
southern portion of the Pine Nut PMU where B. tectorum has readily
invaded a recent burn in the Minnehaha Canyon area. In 2007, the Adrian
Fire burned about 5,600 ha (14,000 ac) of important nesting habitat at
the north end of the Pine Nut PMU. Although there does appear to be
native grass establishment in the burn, B. tectorum is present and
recovery of this habitat will likely be slow or impossible (Axtell
2008, pers. comm.). In 1996, a wildfire burned in the center of the
Pine Nut PMU, in important brood rearing habitat. The area is
recovering and has little invasive annual grass establishment. However,
after 15 years the burned area has very limited sagebrush cover. While
birds still use the meadow habitat, the number of individuals in the
Pine Nut PMU is small. It is not known to what degree this loss of
habitat has influenced population dynamics in the area but it is likely
that it has and will continue to be a factor in the persistence of the
Pine Nut population given its small size. Across the remainder of the
Bi-State area wildfires occur on an annual basis, however, impacts to
sagebrush habitats have been limited to date. Most species of sagebrush
are killed by fire (West 1983, p. 341; Miller and Eddleman 2000, p. 17;
West and Young 2000, p. 259), and historic fire-return intervals were
as long as 350 years, depending on sagebrush type and environmental
conditions (Baker in press, p. 16). Natural sagebrush recolonization in
burned areas depends on the presence of adjacent live plants for a seed
source or on the seed bank, if present (Miller and Eddleman 2000, p.
17), and requires decades for full recovery.
Summary: Fire
Within the Bi-State area, wildfire is a potential threat to greater
sage-grouse habitat in all PMUs. To date few large landscape scale
fires have occurred and we have not yet seen changes to the fire cycle
(e.g., shorter) due to invasion by nonnative annual grasses. The BLM
and USFS manage the area under what is essentially a full-suppression
fire-fighting policy given adequate resources. Based on the available
information, wildfire is not currently a significant threat to the Bi-
State DPS of the greater sage-grouse. However, the future threat of
wildfire, given the fragmented nature and small size of the populations
within the DPS, would have a significant effect on the overall
viability of the DPS based on its effects on the habitat in the Pine
Nut PMU.
Invasive Species, Noxious Weeds, and Pinyon-Juniper Encroachment
A variety of nonnative, invasive plant species are present in all
PMUs that comprise the Bi-State area, with Bromus tectorum (cheatgrass)
being of greatest concern. (For a general discussion on the effects of
non-native and invasive plant species, please see Invasive plants under
Factor A in the GSG finding above).
Wisdom et al. (2003, pp. 4-3 to 4-13) assessed the risk of Bromus
tectorum displacement of native vegetation for Nevada and reported that
44 percent of existing sagebrush habitat is either at moderate or high
risk of displacement and correspondingly 56 percent of sagebrush
habitat is at low risk of displacement. In conjunction with Wisdom et
al. (2003), Rowland et al. (2003, p. 40) found that 48 percent of
greater sage-grouse habitat on lands administered by the BLM Carson
City Field Office is at low risk of B. tectorum replacement, about 39
percent is at moderate risk, and about 13 percent is at high risk. Both
assessments, however, included large portions of land outside the Bi-
State area. Peterson (2003), in association with the Nevada Natural
Heritage Program, estimated percent cover of B. tectorum in
approximately the northern half of the Bi-State area using satellite
data. Land managers and this satellite data assessment indicate that B.
tectorum is present throughout the Bi-State area but percent cover is
low. Conversion to an annual grass dominated community is limited to
only a few locations. Areas of greatest concern are along main travel
corridors and in the Pine Nut, Bodie, and Mount Grant PMUs.
Bromus tectorum out-competes beneficial understory plant species
and can dramatically alter fire ecology (See Wildfire discussion
above). In the Bi-State area, essential sage-grouse habitat is often
highly concentrated and a fire event would have significant adverse
effects to sage-grouse populations. Land managers have had little
success preventing B. tectorum invasion in the West. Occurrence of B.
tectorum in the Bi-State area is apparent at elevations above that
thought to be relatively immune based on the grass's ecology. This
suggests that few locations in the Bi-State area will be safe from B.
tectorum invasion in the future. Climate change may strongly influence
the outcome of these interactions; the available data suggest that
future conditions will be most influenced by precipitation (Bradley
2008, p. 9) (Also see Climate Change discussion below).
Pinyon-juniper encroachment into sagebrush habitat is a threat
occurring in the Bi-State area (USFS 1966, p. 22). Pinyon-juniper
encroachment is occurring to some degree in all PMUs, with the greatest
loss and fragmentation of important sagebrush habitat in the Pine Nut,
Desert Creek-Fales, Mount Grant, and Bodie PMUs (Bi-State Plan 2004,
pp. 20, 39, 96, 133, 137, 167). No data exist for the Bi-State area
that quantify the amount of sagebrush habitat lost to encroachment, or
that clearly demonstrate pinyon-juniper encroachment has caused greater
sage-grouse populations to decline. However, land managers consider it
a significant threat impacting habitat quality, quantity and
connectivity and increasing the risk of avian predation to sage-grouse
populations (Bi-State Plan 2004, pp. 20, 39, 96) and several previously
occupied locations are thought to have been abandoned due to
encroachment (Bi-State Plan 2004, pp. 20, 133). Management treatment of
pinyon-juniper is feasible but is often constrained by competing
resource values and cost. Several thinning projects have been completed
in the Bi-State area, accounting for approximately 1,618 ha (4,000 ac)
of woodland removed.
Summary: Invasive Species, Noxious Weeds, Pinyon-Juniper Encroachment
While the current occurrence of Bromus tectorum in the Bi-State
area is relatively low, it is likely the species will continue to
expand and adversely impact sagebrush habitats and the greater sage-
grouse by out-competing beneficial understory plant species and
altering the fire ecology of the area. Alteration of the fire ecology
of the Bi-State area is of greatest concern (see Fire
[[Page 14000]]
discussion above). Land managers have had little success preventing B.
tectorum invasion in the West and elevational barriers to invasion are
not apparent in the Bi-State area. While climate change may strongly
influence the outcome of these interactions, the available data suggest
that future conditions will be most influenced by precipitation
(Bradley 2008, p. 9). Bromus tectorum is a serious threat to the
sagebrush shrub community and will be detrimental to greater sage-
grouse in the Bi-State area. Encroachment of sagebrush habitats by
woodlands is occurring throughout the Bi-State area and continued
isolation and reduction of suitable habitats will influence both short-
and long-term persistence of sage-grouse.
Climate Change
Global climate change is expected to affect the Bi-State area
(Lenihan et al. 2003, p. 1674; Diffenbaugh et al. 2008, p. 3; Lenihan
et al. 2008, p. S223). Impacts are not well defined and precise
predictions are problematic due to the coarse nature of the climate
models and relatively small geographic extent of the area. In general,
model predictions tend to agree on an increasing temperature regime
(Cayan et al. 2008, pp. S38-S40). Model predictions for the Bi-State
area, using the mid-range ensemble emissions scenario, show an overall
increase in annual temperatures, with some areas projected to
experience mean annual temperature increases of 1 to 3 degrees
Fahrenheit over the next 50 years (TNC Climate Wizard, 2009). Of
greater uncertainty is the influence of climate change on local
precipitation (Diffenbaugh et al. 2005, p. 15776; Cayan et al. 2008, p.
S28). This variable is of major importance to greater sage-grouse, as
timing and quantity of precipitation greatly influences plant community
composition and extent, specifically forb production, which in turn
affects nest and chick survival. Across the west, models predict a
general increase in precipitation (Neilson et al. 2005, p. 150),
although scaled-down predictions for the Bi-State area show an overall
decrease in annual precipitation ranging from under 1 inch up to 3
inches over the next 50 years (TNC Climate Wizard 2009).
A warming trend in the mountains of western North America is
expected to decrease snow pack, accelerate spring runoff, and reduce
summer stream flows (Intergovernmental Panel on Climate Change (IPCC)
2007, p. 11). Specifically in the Sierra Nevada, March temperatures
have warmed over the last 50 years resulting in more rain than snow
precipitation, which translates into earlier snowmelt. This trend is
likely to continue and accelerate into the future (Kapnick and Hall
2009, p. 11). This change in the type of precipitation and the timing
of snow melt will influence reproductive success by altering the
availability of understory vegetation and meadow habitats. Increased
summer temperature is also expected to increase the frequency and
intensity of wildfires. Westerling et al. (2009, pp. 10-11) modeled
potential wildfire occurrences as a function of land surface
characteristics in California. Their model predicts an overall increase
in the number of wildfires and acreage burned by 2085 (Westerling et
al. 2009, pp. 17-18). Increases in the number of sites susceptible to
invasive annual grass and increases in WNv outbreaks are reasonably
anticipated (IPCC 2007, p. 13; Lenihan et al. 2008, p. S227). Reduction
in summer precipitation is expected to produce the most suitable
condition for B. tectorum. Recent warming is linked, in terrestrial
ecosystems, to poleward and upward shifts in plant and animal ranges
(IPCC 2007, p. 2).
While it is reasonable to assume the Bi-State area will experience
vegetation changes, we do not know how climate change will ultimately
effect this greater sage-grouse population. It is unlikely that the
current extent of shrub habitat will remain unchanged, whether the
shift is toward a grass or woodland dominated system is unknown. Either
result will negatively affect greater sage-grouse in the area.
Additionally, it is also reasonable to assume that changes in
atmospheric carbon dioxide levels, temperature, precipitation, and
timing of snowmelt, will act synergistically with other threats such as
wildfire and invasive species to produce yet unknown but likely
negative effects to greater sage-grouse habitat and populations in the
Bi-State area.
Summary of Factor A
Destruction and modification of greater sage-grouse habitat is
occurring and will continue in the Bi-State area due to urbanization,
infrastructure (e.g., fences, powerlines, and roads), mining, renewable
energy development, grazing, wildfire, and invasive plant species. At
the individual PMU level the impact and timing of these threats vary.
The Pine-Nut PMU has the lowest number of individuals of all Bi-State
area (approximately 89 to 107 in 2009) PMUs and is threatened by
urbanization, grazing management, wildfire, invasive species, and
energy development. The threats to habitat in this PMU are likely to
continue in the future which may result in continued declines in the
populations over the short term.
The Desert-Creek Fales PMU contains the greatest number of sage-
grouse of all Bi-State PMUs in Nevada (approximately 512 to 575 in
2009). The most significant threats in this PMU are wildfire, invasive
species (specifically conifer encroachment), urbanization, and
fragmentation. Private lands purchase in California and pinyon-juniper
forest removal in Nevada reduced some of the threats at two important
locations within this PMU. However, a recent proposal for a land parcel
subdivision in proximity to Burcham Flat, California, threatens nesting
habitat and one of the two remaining leks in the area. The imminence of
these threats varies, however, with urbanization and fragmentation
being the most imminent threats to habitat in this PMU.
The Mount Grant PMU has an estimated population of 376 to 427
individuals based on 2009 surveys. Threats in this PMU include
renewable energy development and mining associated infrastructure.
Additional threats include infrastructure (fences, powerlines, and
roads), conifer encroachment, fragmentation, and impacts to mesic
habitat on private land from grazing and water table alterations. These
threats currently fragment, and may in the future continue to fragment
habitat in this PMU and reduce or eliminate connectivity to populations
in the Bodie Hills PMU to the west.
The Bodie and South Mono PMUs are the core of greater sage-grouse
populations in the Bi-State area, and have estimated populations of 829
to 927 and 906 to 1,012 individuals based on 2009 surveys,
respectively. These two PMUs comprise approximately 65 percent of the
total population in the Bi-State area. Future loss or conversion of
limited brood rearing habitat on private lands in the Bodie PMU is a
significant threat to the population. The threat of future wildfire and
subsequent habitat loss of conversion to annual grassland is of great
concern. Threats from existing and future infrastructure, grazing,
mineral extraction, and conifer encroachment are also present but
believed to have a relatively lower impact. The most significant threat
in the South Mono PMU involves impacts associated with human activity
in the forms of urbanization and recreation. Other threats in this PMU
include existing and future infrastructure, mining activities, and
wildfire, but pose a relatively lower risk to habitat and the DPS.
Information on threats in White Mountains PMU is limited. The area
is
[[Page 14001]]
remote and difficult to access and most data are in the form of random
observations. Threats to the habitat in this PMU are low due to the
remote location. Activities such as grazing, recreation, and invasive
species may be influencing the population but this is speculation.
Potential future actions in the form of transmission line, road, and
mineral developments are threats that could lead to the loss of the
remote but contiguous nature of the habitat.
Predicting the impact of global climate change on sage-grouse
populations is challenging due to the relatively small spatial extent
of the Bi-State area. It is likely that vegetation communities will not
remain static and the amount of sagebrush shrub habitat will decrease.
Further, increased variation in drought cycles due to climate change
will likely place additional stress on sage-grouse habitat and
populations. While greater sage-grouse evolved with drought, drought
has been correlated with population declines and shown to be a limiting
factor to population growth in areas where habitats have been
compromised.
Taken cumulatively, the habitat-based threats in all PMUs will
likely act to fragment and isolate populations of the DPS in the Bi-
State area. Over the short term (10 years) the persistence of the Pine
Nut PMU is not likely. Populations occurring in the Desert Creek-Fales
and Mount Grant PMUs are under significant pressure and continued
threats to habitat will likely increase likelihood of extirpation. The
Bodie and South Mono PMUs are larger and more stable and should
continue to persist. While the South Mono PMU appears to be an isolated
entity, the Bodie PMU interacts with the Mount Grant and the Desert
Creek-Fales PMUs, and the continued loss of habitat in these other
locations will likely influence the population dynamics and possibly
the persistence of the breeding population occurring in the Bodie PMU.
The White Mountain PMU is likely already an isolated population and
does not currently or would in the future contribute to the South Mono
PMU.
Therefore, based on our review of the best scientific and
commercial data available, we conclude threats from the present or
threatened destruction, modification, or curtailment of greater sage-
grouse habitat or range are significant to the Bi-State DPS of the
greater sage-grouse.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Hunting
The only known assessment of hunting effects specific to the Bi-
State area is an analysis conducted by Gibson (1998) for the Bodie
Hills and Long Valley lek complexes. This assessment indicated that
populations in the South Mono PMU (Long Valley area) were depressed by
hunting from the late 1960's to 2000 but the Bodie Hills population was
not. The results of Gibson (1998) influenced the CDFG management of the
Long Valley population through the limitation of allocated hunting
permits (Gardner 2008, pers. comm.).
Prior to 1983, California had no limit on hunting permits in the
area which covers the Bodie Hills portion of the Bodie PMU (North Mono
Hunt Area) and the Long Valley portion of the South Mono PMU (South
Mono Hunt Area). In 1983, CDFG closed the hunting season (Bi-State Plan
2004, pp. 73-74); however, it was reopened in 1987 when CDFG instituted
a permit system that resulted in limiting the number of permits
(hundreds) issued annually. In 1998, the number of permits issued was
significantly reduced (Bi-State Plan 2004, pp. 74-75; Gardner 2008,
pers. comm.).
From 1998 to the present, the number of hunting permits issued by
the CDFG has ranged from 10 to 35 per year for the North Mono and South
Mono Hunt Areas (Bi-State Plan 2004, p. 173; CDFG 2008). In 2008, 25
single bird harvest permits were issued for the North Mono Hunt Area,
and 35 single bird harvest permits were issued for the South Mono Hunt
Area (CDFG 2008). Assuming all permits were filled, and comparing these
estimated harvest levels to the low spring population estimates for the
Bodie and South Mono PMUs for 2008, there was an estimated loss of
about 4 percent for each population (25 of 573 and 35 of 838 for Bodie
PMU and South Mono PMU, respectively). These harvest levels are within
the harvest rate of 10 percent or less recommended by Connelly et al.
(2000a, p. 976). The CDFG evaluated the effect of their greater sage-
grouse hunting season for California as part of an overall assessment
of the effects of their resident game bird hunting seasons (CDFG 2002).
They concluded that the removal of individual animals from resident
game bird populations statewide (including greater sage-grouse) will
not significantly reduce those populations and will therefore not have
a significant environmental impact on resident game birds (CDFG 2002,
p. 7).
Hunting (gun) has been closed in the Nevada portion of the Bi-State
area since 1999 (NDOW 2006, p. 2). The falconry season in this area was
closed in 2003 (Espinosa 2006b, pers. comm.). The Washoe Tribe has
authority over hunting on tribal allotments in the Pine Nut PMU. There
are anecdotal reports of harvest by Tribal members but currently the
Washoe Tribe Hunting and Fishing Commission does not issue harvest
permits for greater sage-grouse nor are historical harvest records
available (J. Warpea 2009, pers. comm.).
Neither the CDFG nor NDOW had any information on poaching of
greater sage-grouse or the accidental taking of this species by hunters
pursuing other upland game birds with open seasons for the Bi-State
area. Gibson (2001, p. 4) does mention that a low level of known
poaching occurred in Long Valley. Hunting has suppressed some
populations in the Bi-State area historically. Harvest has been
estimated to be as much as 4 percent of the population in Bodie and
South Mono PMUs. While this may be considered to be at levels
considered compensatory and within harvest guidelines, in Long Valley
it likely continues to impact population growth.
Recreational, Scientific, and Religious Use
The CDFG and NDOW provide public direction to leks and guidelines
to minimize viewing disturbance on a case-by-case basis. Overall, lek
locations in the Bi-State area are well known and some are frequently
visited. Disturbance is possible; however, we have no data to suggest
that non-consumptive recreational uses of greater sage-grouse are
impacting local populations in the Bi-State area (Gardner 2008, pers.
comm.; Espinosa 2008, pers. comm.). We are not aware of any studies of
lek viewing or other forms of non-consumptive recreational uses related
to greater sage-grouse population trends. We have no information that
this type of recreational activity is having a negative impact on local
populations or contributing to declining population trends of greater
sage-grouse in the Bi-State area.
Regarding possible effects from scientific studies of greater sage-
grouse, in the past 5 years, approximately 200 greater sage-grouse have
been captured and handled by researchers. Casazza et al. (2009, p. 45)
indicates that, in 3 years of study of radio-marked greater sage-
grouse, the deaths of four birds in the Bi-State area were attributed
to researchers.
[[Page 14002]]
Summary of Factor B
Overall in the Bi-State area hunting is limited to such a degree
that it is not apparently restrictive to overall population growth.
However, hunting was shown to limit the population of greater sage-
grouse occurring within the South Mono PMU historically and even at its
current reduced level still likely suppresses this population. While
hunting in the Bodie PMU appears to be compensatory, given this PMU's
connection with the neighboring and non-hunted Mount Grant PMU and the
current declines apparent in the Mount Grant population, additional
evaluation of this hunting across jurisdictional boundaries is
warranted. We have no information indicating poaching, non-consumptive
uses, or scientific use significantly impact Bi-State greater sage-
grouse populations, either separately of collectively. Therefore, based
on our review of the best scientific and commercial data available we
find that overutilization for commercial, recreational, scientific, or
educational purposes is not a significant threat to the Bi-State DPS of
the greater sage-grouse.
Factor C: Disease and Predation
Disease
West Nile virus (WNv) is the only identified disease that warrants
concern for greater sage-grouse in the Bi-State area. Small
populations, such as those in the Bi-State area, are at higher risk of
extirpation due to their low numbers and the additive mortality WNv
causes (see Disease discussion under Factor C in the GSG finding,
above). Larger populations may be better able ``absorb'' losses due to
WNv simply due to their size (Walker and Naugle in press, p. 25). The
documented loss of four greater sage-grouse to WNv in the Bodie (n=3)
and Desert Creek-Fales (n=1) PMUs (Casazza et al. 2009, p. 45) has
heightened our concern about the impact of this disease in the Bi-State
area, especially given the small population sizes. These mortalities
represented four percent of the total greater sage-grouse mortalities
observed, but additional reported mortality due to predation could have
been due in part to disease-weakened individuals. Mortality caused by
disease acts in a density independent, or additive, manner. While four
percent may not appear substantial, the fact that it can act
independently of habitat and has the potential to suppress a population
below carrying capacity makes disease of a greater concern.
Annual and spatial variations in temperature and precipitation
influence WNv outbreaks. Much of the Bi-State area occurs at relatively
high elevations with short summers, and these conditions likely limit
the extent of mosquito and WNv occurrence, or at least may limit
outbreaks to the years with above-average temperatures. The Bi-State
area represents the highest known elevation at which greater sage-
grouse have been infected with WNv, about 2,300 m (7,545 ft; Walker and
Naugle in press, p. 12). Casazza et al. (2009) captured birds in the
White Mountains, South Mono, Bodie, and California portion of the
Desert Creek-Fales PMUs, and mortality rates at these locations may not
be representative of the remainder of the Bi-State area, which occurs
at lower elevations on average. The WNv was first documented in the
State of California in 2003 (Reisen et al. 2004, p. 1369), thus, the
impact of the virus during the 2003-2005 study years may be an
underrepresentation of current conditions. From 2004 to 2008, the U.S.
Geological Survey reported 79 cases of WNv in birds (species undefined)
from Mono, Douglas, Lyon, and Mineral Counties (http://diseasemaps.usgs.gov), accessed February 27, 2009).
The extent that WNv influences greater sage-grouse population
dynamics in the Bi-State area is uncertain, and barring a severe
outbreak, natural variations in survival and reproductive rates that
drive population growth may be masking the true impact of the disease.
However, the dramatic fluctuations in recent lek counts in the Desert
Creek-Fales and Mount Grant PMUs may indicate past outbreaks. Based on
our current knowledge of the virus, the relatively high elevations and
cold temperatures common in much of the Bi-State area likely reduce the
chance of a population-wide outbreak. However, there may be localized
areas of significant outbreaks that could influence individual
populations. West Nile virus is a relatively new source of mortality
for greater sage-grouse and to date has been limited in its impact in
the Bi-State area. Although predicting precisely when and where further
outbreaks will occur is not possible, the best scientific data
available support a conclusion that outbreaks are very likely to
continue to occur. However, the loss of individual populations from WNv
outbreaks, which is particularly a risk for smaller populations, may
influence the persistence of the Bi-State DPS through the loss of
redundancy to the overall population and the associated challenges of
recolonizing extirpated sites through natural emigration.
Predation
Range-wide, annual mortality of breeding-age greater sage-grouse
varies from 55 to 75 percent for females and 38 to 60 percent for
males, with the majority of mortality attributable to predation
(Schroeder and Baydack 2001, p. 25). Although not delineated by sex,
the best data available for the Bi-State population reports apparent
annual adult mortality due to predation of between 58 and 64 percent
(Casazza et al. 2009, p. 45). This loss of radio-collared greater sage-
grouse in the Bi-State area to predators is well within normal levels
across the range of the species. However, estimates of adult survival
vary substantially across the Bi-State area and in several locations
adult survival in the Bi-State area is below that considered
sustainable by some researchers (Farinha et al. 2008, unpublished data;
Sedinger et al. unpublished data., p. 12). Where good-quality habitat
is not a limiting factor, research suggests it is unlikely that
predation influences the persistence of the species (see Predation
under the Greater sage-grouse finding above). Thus, we consider the low
estimates of adult survival in the northern half of the Bi-State area
to be a manifestation of habitat degradation or other anthropogenic
factors that can alter natural predator-prey dynamics such as
introduced nonnative predators or human-subsidized native predators.
Nest success across the Bi-State area is within the normal range,
with some locations even higher than previously documented (Kolada
2007, p. 52). The lowest estimates occur in Long Valley (21 percent;
Kolada 2007, p. 66). The low estimates in Long Valley are of concern as
this population represents the stronghold for the species in the Bi-
State area and is also the population most likely exposed to the
greatest predation (Coates 2008, pers. comm.). Although significantly
more birds were present in the past, the Long Valley population appears
stable. The negative impact from reduced nesting success is presumably
being offset by other demographic statistics such as high chick or
adult survival.
Summary of Factor C
We have a poor understanding of the effects of disease on Bi-State
greater sage-grouse populations, and we are concerned about the
potential threat, especially in light of recent documented presence of
WNv and the potential impacts this disease can have on population
growth. WNv is a substantial mortality factor for greater sage-grouse
populations when outbreaks occur. We
[[Page 14003]]
will continue to monitor future infections and observe population
response. Predation is the primary cause of mortality in the Bi-State
area (Casazza et al. 2009, p. 45), as it is for greater sage-grouse
throughout its range (see discussion of predation related to the
greater sage-grouse rangewide, above). In several locations in the
northern Bi-State area (Bodie Hills, Desert Creek, Fales), adult
survival is below what some researchers consider to be sustainable
(Farinha et al. 2008, unpublished data; Sedinger et al. unpublished
data., p. 12). Low (21 percent) nest success in at least one area (Long
Valley) may be associated with higher local densities of predators
(Coates 2008, pers. comm.). Studies suggest predator influence is more
pronounced in areas of poor habitat conditions. The ultimate cause of
reduced population growth and survival appears to stem from impacts
from degraded habitat quality. The impacts from roads, powerlines, and
other anthropogenic features (landfills, airports, and urbanization)
degrade habitat quality and increase the densities of native and
nonnative predators which results in negative effects to greater sage-
grouse population dynamics. Therefore, after reviewing the best
scientific and commercial data available we have determined that
disease and predation are threats to the Bi-State DPS, although the
impact of these threats is relatively low and localized at this time
compared to other threats.
Factor D: Inadequacy of Existing Regulatory Mechanisms
As discussed in Factor D of the GSG finding above, existing
regulatory mechanisms that could provide some protection for greater
sage-grouse include: (1) local land use laws, processes, and
ordinances; (2) State laws and regulations; and (3) Federal laws and
regulations. Actions adopted by local groups, states, or federal
entities that are discretionary, including conservation strategies and
guidance, are not regulatory mechanisms.
Local Laws and Regulations
Approximately 8 percent of the land in the Bi-State area is
privately owned (Bi-State Plan 2004). We are not aware of any existing
county or city ordinances that provide protection specifically for the
greater sage-grouse or their habitats on private lands.
State Laws and Regulations
In the Bi-State area, greater sage-grouse are managed by two state
wildlife agencies (NDOW and CDFG) as resident native game birds. The
game bird classification allows the direct human taking of greater
sage-grouse during hunting seasons authorized and conducted under state
laws and regulations. Currently, harvest of greater sage-grouse is
authorized in two hunt units in California, covering approximately the
Long Valley and Bodie Hills populations (CDFG 2008). Greater sage-
grouse hunting is prohibited in the Nevada portion of the Bi-State
area, where the season has been closed since 1999 (Greater Sage-Grouse
Conservation Plan for Nevada and Eastern California 2004, pp. 59-61).
Each State bases its hunting regulations on local population
information and peer-reviewed scientific literature regarding the
impacts of hunting on the greater sage-grouse. Hunting seasons or
closures are reviewed annually, and States implement adaptive
management based on harvest and population data (Espinosa 2008, pers.
com.; Gardner 2008, pers. com.). Based on the best data available, we
can not determine whether or how hunting mortality, is affecting the
populations. Therefore, we do not have information to indicate how
regulated hunting is affecting the DPS.
State agencies directly manage approximately 1 percent of the total
landscape dominated by sagebrush in the Bi-State area, and various
State laws and regulations identify the need to conserve wildlife
habitat (Bi-State Plan 2004). Laws and regulations in both California
and Nevada allow for acquisition of funding to acquire and conserve
wildlife habitats, including land purchases and entering into easements
with landowners. California recently purchased approximately 470 ha
(1,160 ac) in the Desert Creek-Fales PMU largely for the conservation
of greater sage-grouse (Taylor 2008, pers. com.). However, any
acquisitions authorized are discretionary on the part of the agencies
and cannot be considered an adequate mechanism that alleviates threats
to the DPS or its habitat.
The Bi-State Plan (2004) represents more than 2 years of
collaborative analysis by numerous local biologists, land managers, and
land users who share a common concern for the greater sage-grouse
occurring in western Nevada and eastern California. The intent of the
plan was to identify factors that negatively affect greater sage-grouse
populations in the Bi-State area as well as conservation measures
likely to ameliorate these threats and maintain these populations.
These efforts are in addition to current research and monitoring
efforts conducted by the States. These voluntary recommended
conservation measures are in various stages of development and depend
on the cooperation and participation of interested parties and
agencies. The Bi-State Plan does not include any prohibitions against
actions that harm greater sage-grouse or their habitat. Since
development of the Bi-State Plan, the NDOW has committed approximately
$250,000 toward conservation efforts, some of which have been
implemented while others are pending. Other support has come from
various federal, state, and local agencies. For example, a partnership
between the NDOW and the USFS resulted in a recently completed pinyon-
juniper removal project in the Sweetwater Range in the Desert Creek-
Fales PMU encompassing about 1,300 ha (3,200 ac) of important greater
sage-grouse habitat (NDOW 2008, p. 24). Additional efforts are also
being developed to target restoration of important nesting, brood
rearing, and wintering habitat components across the Bi-State area.
However, the Bi-State Plan is not a regulation and its implementation
depends on voluntary efforts. Thus the Bi-State Plan can not be
considered to be an adequate regulatory mechanism.
The California Environmental Quality Act (CEQA) (Public Resources
Code sections 21000-21177), requires full disclosure of the potential
environmental impacts of projects proposed by state and local agencies.
The public agency with primary authority or jurisdiction over the
project is responsible for conducting an environmental review of the
project, and consulting with the other agencies concerned with the
resources affected by the project. Section 15065 of the CEQA guidelines
requires a finding of significance if a project has the potential to
``reduce the number or restrict the range of a rare or endangered plant
or animal.'' Species that are eligible for listing as rare, threatened,
or endangered but are not so listed are given the same protection as
those species that are officially listed with the State. However, once
significant effects are identified, the lead agency has the option to
mitigate the effects through changes in the project, or decide that
overriding considerations, such as social or economic considerations,
make mitigation infeasible (CEQA section 21002). In the latter case,
projects may be approved that cause significant environmental damage,
such as destruction of endangered species, and their habitat.
Protection of listed species through CEQA is dependent upon the
[[Page 14004]]
discretion of the agency involved. Therefore, CEQA may not act as a
regulatory mechanism for the protection of the DPS.
Federal Laws and Regulations
Federally owned and managed land make up the majority of the
landscape within the DPS's range. For a comprehensive discussion and
analysis of federal laws and regulations please see this section under
Factor D of the GSG finding.
Approximately 50 percent of the land base in the Bi-State area
occurs on lands managed by the BLM. As stated in the GSG finding, FLPMA
is the primary federal law governing most land uses on BLM-administered
lands. Under FLPMA, the BLM has authority over livestock grazing,
recreation, OHV travel and human disturbance, infrastructure
development, fire management, and either in combination with or under
the MLA and other mineral and mining laws, energy development and
mining on its lands. In Nevada and California, the BLM manages for many
of these activities within their jurisdiction. In Nevada and
California, the BLM has designated the greater sage-grouse a sensitive
species. BLM's management of lands in the Bi-State area is conducted
consistent with its management of its lands across the greater sage-
grouse range. Therefore, we refer the reader to the GSG finding above
for a detailed discussion and analysis BLM's management of sage-grouse
habitat on its lands.
The USFS manages approximately 35 percent of the land base in the
Bi-State area. As stated in the GSG finding, management of activities
on lands under USFS jurisdiction is guided principally by NFMA through
associated LRMPs for each forest unit. Under NFMA and other federal
laws, the USFS has authority to regulate recreation, OHV travel and
other human disturbance, livestock grazing, fire management, energy
development, and mining on lands within its jurisdiction. Please see
the GSG finding for general information and analysis. All of the LRMPs
that currently guide the management of sage-grouse habitats on USFS
lands were developed using the 1982 implementing regulations for land
and resource management planning (1982 Rule, 36 CFR 219), including two
existing USFS LRMPs (USFS 1986, 1988) within greater sage-grouse
habitat in the Bi-State area.
The greater sage-grouse is designated as a USFS Sensitive Species
in the Intermountain Region (R4) and Pacific Southwest Region (R5),
which include the Humboldt-Toiyabe National Forest's Bridgeport Ranger
District and the Inyo National Forest in the Bi-State area. The
specifics of how sensitive species status has conferred protection to
sage-grouse on USFS lands varies significantly across the range, and is
largely dependent on LRMPs and site-specific project analysis and
implementation. The Inyo National Forest identifies sage-grouse as a
Management Indicator Species. This identification requires the USFS to
establish objectives for the maintenance and improvement of habitat for
the species during all planning processes, to the degree consistent
with overall multiple use objectives (1982 rule, 36 CFR 219.19(a)).
As part of the USFS Travel Management planning effort, both the
Humboldt-Toiyabe National Forest and the Inyo National Forest are
revising road designations in their jurisdictions. The Humboldt-Toiyabe
National Forest released its Draft Environmental Impact Statement in
July, 2009. The Inyo National Forest completed and released its Final
Environmental Impact Statement and Record of Decision in August 2009
for Motorized Travel Management. The ROD calls for the permanent
prohibition on cross country travel off designated authorized roads.
However, since this prohibition is not specific to sage-grouse habitat
and we cannot assess how this will be enforced, we cannot consider the
policy to be a regulatory mechanism that can protect the DPS.
Additional federally managed lands in the Bi-State area include the
DOD Hawthorne Army Depot, which represents less than 1 percent of the
total land base. However, these lands provide relatively high quality
habitat (Nachlinger 2003, p. 38) and likely provide some of the best
greater sage-grouse habitat remaining in the Mount Grant PMU because of
the exclusion of livestock and the public (Bi-State Plan 2004, p. 149).
There are no National Parks or National Wildlife Refuges in any of the
PMUs in the Bi-State area, and we are unaware of any private lands in
the area that are enrolled in the United States Department of
Agriculture Conservation Reserve Program.
Summary of Factor D
As described above, habitat destruction and modification in the Bi-
State area is a threat to the DPS. Federal agencies' abilities to
adequately address several issues such as wildfire, invasive species,
and disease across the Bi-State area are limited. For other stressors
such as grazing, the regulatory mechanisms in place could be adequate
to protect sage-grouse habitats; however, the application of these
mechanisms varies. In some locations rangelands are not meeting habitat
standards necessary for sage-grouse persistence, however, overall
population estimates, while variable from year-to-year, show no
discernable trend attributable to grazing.
The statutes, regulations, and policies guiding renewable energy
development and associated infrastructure development, and mineral
extraction for the greater sage-grouse range-wide generally are
implemented similarly in the Bi-State area as they are across the range
of the greater sage-grouse, and it is our conclusion that this
indicates that current measures do not ameliorate associated impacts to
the DPS.
The existing state and federal regulatory mechanisms to protect
greater sage-grouse in the Bi-State area afford sufficient discretion
to decision makers as to render them inadequate to ameliorate threats
to the Bi-State DPS. We do not suggest that all resource decisions
impacting sage-grouse have failed to adequately address sage-grouse
needs and in fact commend the individuals and agencies working in the
Bi-State area. However, the flexibility built into the regulatory
process greatly reduces the adequacy of these mechanisms. Because of
this, the available regulatory mechanisms are not sufficiently reliable
to provide for conservation of the species in light of the alternative
resource demands. Therefore, after a review of the best scientific and
commercial data available, we find that the existing regulatory
mechanisms are inadequate to ameliorate the threats to the Bi-State DPS
of the greater sage-grouse.
Factor E: Other Natural or Manmade Factors Affecting the Species'
Continued Existence
Recreational Activities
A variety of recreational activities are pursued across the Bi-
State area, including traditional activities such as fishing, hiking,
horseback riding, and camping as well as more recently popularized
activities, such as off-road-vehicle travel and mountain biking. As
discussed under Recreational Activities under Factor E in the GSG
finding above, these activities can degrade habitat and affect sage-
grouse reproduction and survival by causing disturbance in these areas.
The Bi-State Plan (2004) discusses the risk associated with off-
road vehicles in the Pine Nut and the Mount Grant PMUs (Bi-State Plan
2004, pp. 27, 137-138). Additionally, for the Bodie and South Mono
PMUs, the Bi-State Plan (2004, pp. 91-92, 170-171) discusses off-road
vehicles in the context of all
[[Page 14005]]
types of recreational activities (motorized and non-motorized). We are
not aware of any scientific reports that document direct mortality of
greater sage-grouse through collision with off-road vehicles (70 FR
2278), although mortality from collision with vehicles on U.S. 395 near
Mammoth Lakes is known (Wiechmann 2008, p. 3). Off-road vehicle use has
indirect impacts to greater sage-grouse habitat; it is known to reduce
or eliminate sagebrush canopy cover through repeated trips in an area,
degrade meadow habitat, increase sediment production, and decrease soil
infiltration rates through compaction (70 FR 2278).
Potential disturbance caused by nonmotorized forms of recreation
(fishing, camping, hiking, big game hunting, dog training) are most
prevalent in the South Mono and Bodie PMUs. These PMUs are also exposed
to tourism-associated activity centered around Mono Lake and the towns
of Mammoth Lakes and Bodie. The exact amount of recreational activity
or user days occurring in the area is not known, however, the number of
people in the area is increasing annually (Nelson 2008, pers. comm.;
Taylor 2008, pers. comm.). Additionally, with the recent
reestablishment of commercial air service to the Mammoth Yosemite
Airport during the winter, greater sage-grouse in the South Mono PMU
will be exposed to more flights during leking and the early nesting
season than previously experienced. The early nesting season (in
addition to the already busy summer months) will present the most
significant new overlap between birds and human activity in the area.
Leu et al. (2008, p. 1133) reported that slight increases in human
densities in ecosystems with low biological productivity (such as
sagebrush) may have a disproportional negative impact on these
ecosystems due to reduced resiliency to anthropogenic disturbances. The
greatest concern is the relatively concentrated recreational activity
occurring in the South Mono PMU, which overlaps with the single most
abundant greater sage-grouse population in the Bi-State area.
We are unaware of instances where off-road vehicle (including
snowmobile) activity precluded greater sage-grouse use, or affected
survival in the Bi-State area. There are areas where concerns may arise
though, especially in brood rearing and wintering habitats, which are
extremely limited in the Bi-State area. For example, during heavy snow
years, essentially the entire population of birds in Long Valley has
congregated in a very small area (Gardner 2008, pers. comm.). Off-road
vehicle or snowmobile use in occupied winter areas could displace them
to less optimal habitats (Bi-State Plan 2004, p. 91). Given the
likelihood of a continuing influx of people into Mono County,
especially in proximity to Long Valley, with access to recreational
opportunities on public lands, we anticipate effects from recreational
activity will increase.
Life History Traits Affecting Population Viability
Greater sage-grouse have comparatively slower potential population
growth rates than other species of grouse and display a high degree of
site fidelity to seasonal habitats (see this section under Factor E in
the GSG finding above for further discussion and analysis). While these
natural history characteristics would not limit greater sage-grouse
populations across large geographic scales under historical conditions
of extensive habitat, they may contribute to local declines where
humans alter habitats, or when natural mortality rates are high in
small, isolated populations such as in the case of the Bi-State DPS.
Isolated populations are typically at greater risk of extinction
due to genetic and demographic concerns such as inbreeding depression,
loss of genetic diversity, and Allee effect (the difficulty of
individuals finding one another), particularly where populations are
small (Lande 1988, pp. 1456-1457; Stephens et al. 1999, p. 186;
Frankham et al. 2002, pp. 312-317). The best estimates for the Bi-State
DPS of the greater sage-grouse place the spring breeding population
between 2,000 and 5,000 individuals annually (Gardner 2008, pers.
comm.; Espinosa 2008, pers. comm.). Based on radio-telemetry and
genetic data, the local populations of greater sage-grouse in the Bi-
State area appear to be isolated to varying degrees from one another
(Farinha 2008, pers. comm.). Birds occurring in the White Mountains PMU
as well as those occurring in the Long Valley and Parker Meadows area
of the South Mono PMU are isolated from the remainder of the Bi-State
populations, and apparently from one another (Casazza et al. 2009, pp.
34, 41; Oyler-McCance 2009, pers. comm.). The isolation of populations
occurring to the north of Mono Lake is less clear. Birds occurring in
the Bodie and Mount Grant PMUs mix during parts of the year, as do
birds occurring in the California and Nevada portions of the Desert
Creek-Fales PMUs (Casazza et al. 2009, pp. 13, 21). Within the Mount
Grant PMU, populations occurring on and around Mount Grant do not
interact with populations in the remainder of the PMU. However,
movement of birds between Mount Grant and Desert Creek-Fales or Bodie
and Desert Creek-Fales PMUs appears less consistent. The interaction
among birds occurring in the Pine Nut PMU with PMUs to the south is
unknown. Based on about 150 marked individuals, no dispersal events
were documented among any of the PMUs, suggesting that even though some
populations were mixing during certain times of the year, there was no
documented integration among breeding individuals (Farinha 2008, pers.
comm.). While adults are unlikely to switch breeding populations, it is
likely that genetic material is transferred among these northern
populations through the natural movements of chicks or young of the
year, as long as there are established populations available to
emigrate into.
We have concern regarding viability of populations within PMUs in
the Bi-State area due to their small size (Table 12) and isolation from
one another. Although there is disagreement among scientists and
considerable uncertainty as to the population size adequate for long-
term persistence of wildlife populations, there is agreement that
population viability is more likely to be ensured viability if
population sizes are in the thousands of individuals rather than
hundreds (Allendorf and Ryman 2002, p. 76; Aldridge and Brigham 2003,
p. 30; Reed 2005, p. 565; Traill et al., 2009 entire). For example,
Traill et al. (2009, pp. 30, 32-33) concluded that, in general, both
evolutionary and demographic constraints on wildlife populations
require sizes to be at least 5,000 adult individuals.
The Bi-State population of greater sage-grouse is small and both
geographically and genetically isolated from the remainder of the
greater sage-grouse distribution, which increases risk of genetic,
demographic, stochastic events. To date, however, available genetic
data suggest genetic diversity in the Bi-State area is as high as or
higher than most other populations of greater sage-grouse occurring in
the West (Oyler-McCance and Quinn in press, p. 18). Thus, we currently
do not have clear indications that genetic factors such as inbreeding
depression, hybridization, or loss of genetic diversity place this DPS
at risk. However, recent genetic analysis shows that greater sage-
grouse occupying the White Mountains display a unique allelic frequency
in comparison to other populations in the Bi-State area suggesting
greater isolation (Oyler-McCance 2009, pers. comm.). Additionally,
recent field studies in the Parker Meadows area (a single isolated lek
system located in the South Mono
[[Page 14006]]
PMU) documented a disproportionally high degree of nest failures due to
nonviable eggs (Gardner 2009, pers. comm.).
In addition to the potential negative effects to small populations
due to genetic considerations, small populations such as those found in
the Bi-State area are at greater risk than larger populations from
stochastic events, such as environmental catastrophes or random
fluctuations in birth and death rates, as well disease epidemics,
predation, fluctuations in habitat available, and various other factors
(see Traill et al., p. 29.). Interactions between climate change,
drought, wildfire, WNv, and the limited potential to recover from
population downturns or extirpations place significant impediments to
the persistence of the Bi-State DPS of the greater sage-grouse.
Summary of Factor E
Our analysis shows certain recreational activities have the
potential to directly and indirectly affect sage-grouse and their
habitats. However, based on the information available, it does not
appear that current disturbances are occurring at such a scale that
would adversely affect sage-grouse populations in the Bi-State area.
While this determination is highly constrained by lack of data,
populations in the South Mono PMU, which are arguably exposed to the
greatest degree of recreational activity, appear relatively stable at
present. When issues such as recreation and changes in habitat are
considered in conjunction with other threats, it is likely that
populations in the northern half of the Bi-State area will be
extirpated. Reintroduction efforts involving greater sage-grouse have
had very limited success elsewhere, and natural recolonization of these
areas will be slow or impossible due to their isolation and the limited
number of birds in surrounding PMUs, as well as the constraints
inferred by the species' life history characteristics. Therefore, based
on our evaluation of the best scientific and commercial data available,
we find threats from other natural or manmade factors are significant
to the Bi-State DPS of the greater sage-grouse.
Finding
We have carefully assessed the best scientific and commercial data
available regarding the past, present, and future threats to the Bi-
State DPS of the greater sage-grouse. We have reviewed the petition,
information available in our files, and other published and unpublished
information, and consulted with recognized greater sage-grouse and
sagebrush experts.
Threats identified under Factors A, C, D, and E are a threat to the
Bi-State DPS of the greater sage-grouse. These threats are exacerbated
by the small population sizes, isolated nature, and limited
availability of important seasonal habitats for many Bi-State area
populations. The major threat is current and future destruction,
modification, or curtailment of habitats in the Bi-State area due to
urbanization, infrastructure, mining, energy development, grazing,
invasive and exotic species, pinyon-juniper encroachment, recreation,
wildfire, and the likely effects of climate change. Individually, any
one of these threats appears unlikely to severely affect persistence
across the entire Bi-State DPS of the greater sage-grouse.
Cumulatively, however, these threats interact in such a way as to
fragment and isolate, and will likely contribute to the loss of
populations in the Pine Nut and Desert Creek-Fales PMUs and will result
in a significant range contraction for the Bi-State DPS. The Bodie and
South Mono PMUs currently comprise approximately 65 percent of the
entire DPS and will likely become smaller but persist barring
catastrophic events. In light of on-going threats, the northern extent
of the Bi-State area including the Pine Nut, Desert Creek-Fales, and
Mount Grant PMUs are and will be most at risk. We anticipate loss of
populations and contraction of others which would leave them
susceptible to extirpation from stochastic events, such as wildfire,
drought, and disease.
While sport hunting is currently limited and within harvest
guidelines, if hunting continues it may add to the overall decline of
adult populations in the Bodie and South Mono PMUs. Overall in the Bi-
State area hunting is limited to such a degree that it is not
apparently restrictive to overall population growth. We have no
information indicating poaching, non-consumptive uses, or scientific
use significantly impact Bi-State greater sage-grouse populations.
Therefore, we find that overutilization for commercial, recreational,
scientific, or educational purposes is not a significant threat to the
Bi-State area DPS.
West Nile virus is a threat to the greater sage-grouse, and its
occurrence and impacts are likely underestimated due to lack of
monitoring. While the impact of this disease is currently limited by
ambient temperatures that do not allow consistent vector and virus
maturation, predicted temperature increases associated with climate
change may result in this threat becoming more consistently prevalent.
Predation facilitated by habitat fragmentation due to infrastructure
(fences, powerlines and roads) and other human activities may be
altering natural population dynamics in localized areas such as Long
Valley. We find that disease and predation are threats to the Bi-State
area DPS, although the impact of these threats is relatively low and
localized at this time compared to other threats.
An examination of regulatory mechanisms for both the Bi-State DPS
of the greater sage-grouse and sagebrush habitats revealed that while
some mechanisms exist, it appears that they are being implemented in a
manner that is not consistent with our current understanding of the
species' life history requirements, reaction to disturbances, and
currently understood conservation needs. Therefore, we find the
existing regulatory mechanisms are ineffective at ameliorating habitat-
based threats. Furthermore, certain threats (disease, drought, fire)
may not be able to be adequately addressed by existing regulatory
mechanisms.
Our analysis under Factor E indicates the current level of
recreational activities do not appear to be adversely affecting sage-
grouse populations in the Bi-State area. Populations in the South Mono
PMU, which are arguably exposed to the greatest degree of recreational
activity, appear relatively stable at present.
The relatively low number of local populations of greater sage-
grouse, their small size, and relative isolation is problematic. The
Bi-State area is composed of approximately 35 active leks representing
4 to 8 individual populations. Research has shown fitness and
population size are strongly correlated and smaller populations are
more subject to environmental and demographic stochasticity. When
coupled with mortality stressors related to human activity and
significant fluctuations in annual population size, long-term
persistence of small populations is always problematic.
Given the species' relatively low rate of growth and strong site
fidelity, recovery and repopulation of extirpated areas will be slow
and infrequent. Translocation of this species is difficult and to date
has not been successful, and given the limited number of source
individuals, translocation efforts, if needed, are unlikely.
Within 30 years it is likely that greater sage-grouse in the Bi-
State area will only persist in one or two populations located in the
South Mono PMU (Long Valley) and the Bodie Hills PMU. These populations
will likely be isolated from one another and due to decreased
[[Page 14007]]
population numbers, each will be at greater risk to stochastic events.
As required by the Act, we have reviewed and taken into account
efforts being made to protect the greater sage-grouse in the Bi-State
area. Although some local conservation efforts have been implemented
and are effective in small areas, they are neither individually nor
collectively at a scale that is sufficient to ameliorate threats to the
DPS as a whole, or to local populations. Other conservation efforts are
being planned but there is substantial uncertainty as to whether,
where, and when they will be implemented, and whether they will be
effective.
We have carefully assessed the best scientific and commercial
information available regarding the present and future threats to the
Bi-State DPS of the greater sage-grouse. We have reviewed the
petitions, information available in our files, and other published and
unpublished information, and consulted with recognized greater sage-
grouse and sagebrush experts. We have considered and taken into account
efforts being made to protect the species. On the basis of the best
scientific and commercial information available, we find that listing
of the Bi-State DPS of the greater sage-grouse is warranted across its
range. However, listing this DPS is precluded by higher priority
listing actions at this time, as discussed in the Preclusion and
Expeditious Progress section below.
We have reviewed the available information to determine if the
existing and foreseeable threats render the Bi-State DPS of the greater
sage-grouse at risk of extinction now such that issuing an emergency
regulation temporarily listing the species as per section 4(b)(7) of
the Act is warranted. We have determined that issuing an emergency
regulation temporarily listing the Bi-State DPS is not warranted at
this time (see discussion of listing priority for this DPS, below).
However, if at any time we determine that issuing an emergency
regulation temporarily listing the Bi-State DPS is warranted, we will
initiate this action at that time.
Preclusion and Expeditious Progress
Preclusion is a function of the listing priority of a species in
relation to the resources that are available and competing demands for
those resources. Thus, in any given fiscal year (FY), multiple factors
dictate whether it will be possible to undertake work on a proposed
listing regulation or whether promulgation of such a proposal is
warranted but precluded by higher-priority listing actions.
The resources available for listing actions are determined through
the annual Congressional appropriations process. The appropriation for
the Listing Program is available to support work involving the
following listing actions: proposed and final listing rules; 90-day and
12-month findings on petitions to add species to the Lists of
Endangered and Threatened Wildlife and Plants (Lists) or to change the
status of a species from threatened to endangered; annual
determinations on prior ``warranted but precluded'' petition findings
as required under section 4(b)(3)(C)(i) of the Act; critical habitat
petition findings; proposed and final rules designating critical
habitat; and litigation-related, administrative, and program-management
functions (including preparing and allocating budgets, responding to
Congressional and public inquiries, and conducting public outreach
regarding listing and critical habitat). The work involved in preparing
various listing documents can be extensive and may include, but is not
limited to: gathering and assessing the best scientific and commercial
data available and conducting analyses used as the basis for our
decisions; writing and publishing documents; and obtaining, reviewing,
and evaluating public comments and peer review comments on proposed
rules and incorporating relevant information into final rules. The
number of listing actions that we can undertake in a given year also is
influenced by the complexity of those listing actions; that is, more
complex actions generally are more costly. For example, during the past
several years, the cost (excluding publication costs) for preparing a
12-month finding, without a proposed rule, has ranged from
approximately $11,000 for one species with a restricted range and
involving a relatively uncomplicated analysis, to $305,000 for another
species that is wide-ranging and involved a complex analysis.
We cannot spend more than is appropriated for the Listing Program
without violating the Anti-Deficiency Act (see 31 U.S.C. Sec.
1341(a)(1)(A)). In addition, in FY 1998 and for each FY since then,
Congress has placed a statutory cap on funds which may be expended for
the Listing Program, equal to the amount expressly appropriated for
that purpose in that fiscal year. This cap was designed to prevent
funds appropriated for other functions under the Act (for example,
recovery funds for removing species from the Lists), or for other
Service programs, from being used for Listing Program actions (see
House Report 105-163, 105\th\ Congress, 1st Session, July 1, 1997).
Recognizing that designation of critical habitat for species
already listed would consume most of the overall Listing Program
appropriation, Congress also put a critical habitat subcap in place in
FY 2002, and has retained it each subsequent year to ensure that some
funds are available for other work in the Listing Program: ``The
critical habitat designation subcap will ensure that some funding is
available to address other listing activities'' (House Report No. 107-
103, 107\th\ Congress, 1st Session, June 19, 2001). In FY 2002 and each
year until FY 2006, the Service has had to use virtually the entire
critical habitat subcap to address court-mandated designations of
critical habitat. Consequently, none of the critical habitat subcap
funds have been available for other listing activities. In FY 2007, we
were able to use some of the critical habitat subcap funds to fund
proposed listing determinations for high-priority candidate species. In
FY 2009, while we were unable to use any of the critical habitat subcap
funds to fund proposed listing determinations, we did use some of this
money to fund the critical habitat portion of some proposed listing
determinations, so that the proposed listing determination and proposed
critical habitat designation could be combined into one rule, thereby
being more efficient in our work. In FY 2010, we are using some of the
critical habitat subcap funds to fund actions with statutory deadlines.
Thus, through the listing cap, the critical habitat subcap, and the
amount of funds needed to address court-mandated critical habitat
designations, Congress and the courts have, in effect, determined the
amount of money available for other listing activities. Therefore, the
funds in the listing cap, other than those needed to address court-
mandated critical habitat for already-listed species, set the limits on
our determinations of preclusion and expeditious progress.
Congress also recognized that the availability of resources was the
key element in deciding, when making a 12-month petition finding,
whether we would prepare and issue a listing proposal or instead make a
``warranted but precluded'' finding for a given species. The Conference
Report accompanying Public Law 97-304, which established the current
statutory deadlines for listing and the warranted-but-precluded finding
requirements that are currently contained in the Act, states (in a
discussion on 90-day petition findings that by its own terms also
covers 12-month findings) that the
[[Page 14008]]
deadlines were ``not intended to allow the Secretary to delay
commencing the rulemaking process for any reason other than that the
existence of pending or imminent proposals to list species subject to a
greater degree of threat would make allocation of resources to such a
petition [i.e., for a lower-ranking species] unwise.''
In FY 2010, expeditious progress is that amount of work that can be
achieved with $10,471,000, which is the amount of money that Congress
appropriated for the Listing Program (that is, the portion of the
Listing Program funding not related to critical habitat designations
for species that are already listed). However these funds are not
enough to fully fund all our court-ordered and statutory listing
actions in FY 2010, so we are using $1,114,417 of our critical habitat
subcap funds in order to work on all of our required petition findings
and listing determinations. This brings the total amount of funds we
have for listing actions in FY 2010 to $11,585,417. Our process is to
make our determinations of preclusion on a nationwide basis to ensure
that the species most in need of listing will be addressed first and
also because we allocate our listing budget on a nationwide basis. The
$11,585,417 is being used to fund work in the following categories:
compliance with court orders and court-approved settlement agreements
requiring that petition findings or listing determinations be completed
by a specific date; section 4 (of the Act) listing actions with
absolute statutory deadlines; essential litigation-related,
administrative, and listing program-management functions; and high-
priority listing actions for some of our candidate species. In 2009,
the responsibility for listing foreign species under the Act was
transferred from the Division of Scientific Authority, International
Affairs Program, to the Endangered Species Program. Starting in FY
2010, a portion of our funding is being used to work on the actions
described above as they apply to listing actions for foreign species.
This has the potential to further reduce funding available for domestic
listing actions, although there are currently no foreign species issues
included in our high priority listing actions at this time. The
allocations for each specific listing action are identified in the
Service's FY 2010 Allocation Table (part of our administrative record).
In FY 2007, we had more than 120 species with a Listing Priority
Number (LPN) of 2, based on our September 21, 1983, guidance for
assigning an LPN for each candidate species (48 FR 43098). Using this
guidance, we assign each candidate an LPN of 1 to 12, depending on the
magnitude of threats (high vs. moderate to low), immediacy of threats
(imminent or nonimminent), and taxonomic status of the species (in
order of priority: monotypic genus (a species that is the sole member
of a genus); species; or part of a species (subspecies, DPS, or
significant portion of the range)). The lower the listing priority
number, the higher the listing priority (that is, a species with an LPN
of 1 would have the highest listing priority).
Because of the large number of high-priority species, we further
ranked the candidate species with an LPN of 2 by using the following
extinction-risk type criteria: International Union for the Conservation
of Nature and Natural Resources (IUCN) Red list status/rank, Heritage
rank (provided by NatureServe), Heritage threat rank (provided by
NatureServe), and species currently with fewer than 50 individuals, or
4 or fewer populations. Those species with the highest IUCN rank
(critically endangered), the highest Heritage rank (G1), the highest
Heritage threat rank (substantial, imminent threats), and currently
with fewer than 50 individuals, or fewer than 4 populations, comprised
a group of approximately 40 candidate species (``Top 40''). These 40
candidate species have had the highest priority to receive funding to
work on a proposed listing determination. As we work on proposed and
final listing rules for these 40 candidates, we are applying the
ranking criteria to the next group of candidates with LPNs of 2 and 3
to determine the next set of highest priority candidate species. There
currently are 56 candidate species with an LPN of 2 that have not
received funding for preparation of proposed listing rules.
To be more efficient in our listing process, as we work on proposed
rules for these species in the next several years, we are preparing
multi-species proposals when appropriate, and these may include species
with lower priority if they overlap geographically or face the same
threats as a species with an LPN of 2. In addition, available staff
resources also are a factor in determining high-priority species
provided with funding. Finally, proposed rules for reclassification of
threatened species to endangered are lower priority, since as listed
species, they are already afforded the protection of the Act and
implementing regulations.
We assigned the greater sage-grouse an LPN of 8 based on our
finding that the species faces threats that are of moderate magnitude
and are imminent. These threats include the present or threatened
destruction, modification, or curtailment of its habitat, and the
inadequacy of existing regulatory mechanisms to address such threats.
Under the Service's LPN Guidance, the magnitude of threat is the first
criterion we look at when establishing a listing priority. The guidance
indicates that species with the highest magnitude of threat are those
species facing the greatest threats to their continued existence. These
species receive the highest listing priority. We consider the threats
that the greater sage-grouse faces to be moderate in magnitude because
the threats do not occur everywhere across the range of the species at
this time, and where they are occurring, they are not of uniform
intensity or of such magnitude that the species requires listing
immediately to ensure its continued existence. Although many of the
factors we analyzed (e.g, disease, fire, urbanization, invasive
species) are present throughout the range, they are not to the level
that they are causing a significant threat to greater sage-grouse in
some areas. Other threats are of high magnitude in some areas but are
of low magnitude or nonexistent in other areas such that overall across
the species' range, they are of moderate magnitude. Examples of this
include: oil and gas development, which is extensive in the eastern
part of the range but limited in the western portion; pinyon-juniper
encroachment, which is substantial in some parts of the west but is of
less concern in Wyoming and Montana; and agricultural development which
is extensive in the Columbia Basin, Snake River Plain, and eastern
Montana, but more limited elsewhere. While sage-grouse habitat has been
lost or altered in many portions of the species' range, substantial
habitat still remains to support the species in many areas of its range
(Connelly et al. in press c, p. 23), such as higher elevation
sagebrush, and areas with a low human footprint (activities sustaining
human development) such as the Northern and Southern Great Basin (Leu
and Hanser in press, p. 14) indicating that threats currently are not
high in these areas. The species has a wide distribution across 11
western states. In addition, two strongholds of contiguous sagebrush
habitat (the southwest Wyoming Basin and the Great Basin area
straddling the States of Oregon, Nevada, and Idaho) contain the highest
densities of males in the range of the species (Wisdom et al. in press,
pp. 24-25; Knick and Hanser (in press, p. 17). We believe that the
ability of these strongholds to maintain high densities
[[Page 14009]]
in the presence of several threat factors is an indication that the
magnitude of threats is moderate overall.
We also lack data on the actual future location of where some
potential threats will occur (e.g., wind energy development exact
location, location of the next wildfire). If these threats occur within
unoccupied habitat, the magnitude of the threat to greater sage-grouse
is greatly reduced. The likelihood that some occupied habitat will not
be affected by threats in the foreseeable future leads us to consider
the magnitude of threats to the greater sage-grouse as moderate. This
likelihood is evidenced by our expectation that two strongholds of
contiguous habitat will still remain in fifty years even though the
threats discussed above will continue there.
Under our LPN Guidance, the second criterion we consider in
assigning a listing priority is the immediacy of threats. This
criterion is intended to ensure that the species facing actual,
identifiable threats are given priority over those for which threats
are only potential or that are intrinsically vulnerable but are not
known to be presently facing such threats. We consider the threats
imminent because we have factual information that the threats are
identifiable and that the species is currently facing them in many
portions of its range. These actual, identifiable threats are covered
in great detail in factor A of this finding and include habitat
fragmentation from agricultural activities, urbanization, increased
fire frequency, invasive plants, and energy development.
The third criterion in our LPN guidance is intended to devote
resources to those species representing highly distinctive or isolated
gene pools as reflected by taxonomy. The greater sage-grouse is a valid
taxon at the species level, and therefore receives a higher priority
than subspecies or DPSs, but a lower priority than species in a
monotypic genus.
We will continue to monitor the threats to the greater sage-grouse,
and the species' status on an annual basis, and should the magnitude or
the imminence of the threats change, we will re-visit our assessment of
LPN.
Because we assigned the greater sage-grouse an LPN of 8, work on a
proposed listing determination for the greater sage-grouse is precluded
by work on higher priority candidate species (i.e., entities with LPN
of 7 or lower); listing actions with absolute statutory, court ordered,
or court-approved deadlines; and final listing determinations for those
species that were proposed for listing with funds from FY 2009. This
work includes all the actions listed in the tables below under
expeditious progress (see Tables 13 and 14).
We also have assigned a listing priority number to the Bi-State DPS
of the greater sage-grouse. As described above, under the Service's LPN
Guidance, the magnitude of threat is the first criterion we look at
when establishing a listing priority. The guidance indicates that
species with the highest magnitude of threat are those species facing
the greatest threats to their continued existence. These species
receive a higher listing priority. Many of the threats to the Bi-State
DPS that we analyzed are present throughout the range and currently
impact the DPS to varying degrees (e.g. urbanization, invasive grasses,
habitat fragmentation from existing infrastructure), and will continue
into the future. The northern extent of the Bi-State area including the
Pine Nut, Desert Creek-Fales, and Mount Grant PMUs are now and will
continue to be most at risk. We anticipate loss of some local
populations, and contraction of the range of others which would leave
them susceptible to extirpation from stochastic events, such as
wildfire, drought, and disease. Occupied habitat will continue to be
affected by threats in the future and we expect that only two isolated
populations in the Bodie and South Mono PMUs may remain in thirty
years. The threats that are of high magnitude include: the present or
threatened destruction, modification or curtailment of its habitat and
range; the inadequacy of existing regulatory mechanisms; and other
natural or manmade factors affecting the DPS's continued existence,
such as the small size of the DPS (in terms of both the number of
individual populations and their size) which increases the risk of
extinction, particularly for the smaller local populations. Also the
small number and size and isolation of the populations may magnify the
impact of the other threats. We consider disease and predation to be
relatively low magnitude threats compared to other existing threats.
The Bi-State DPS of the greater sage-grouse is composed of
approximately 35 active leks representing 4 to 8 individual local
populations, based on current information on genetics and connectivity.
While some of the threats do not occur everywhere across the range of
the DPS at this time (e.g. habitat-based impacts from wildfire, WNv
infections), where threats are occurring, the risk they pose to the DPS
may be exacerbated and magnified due to the small number and size and
isolation of local populations within the DPS. We acknowledge that we
lack data on the precise future location of where some impacts will
manifest on the landscape (e.g., effects of climate change, location of
the next wildfire). To the extent to which these impacts occur within
unoccupied habitat, the magnitude of the threat to the Bi-State DPS is
reduced. However, to the extent these impacts occur within habitat used
by greater sage-grouse, due to the low number of populations and small
size of most of them, the effects to the DPS may be greatly magnified.
Due to the scope and scale of the high magnitude threats and current
and anticipated future loss of habitat and isolation of already small
populations, leads us to determine that the magnitude of threats to the
Bi-State DPS of the greater sage-grouse is high.
Under our LPN Guidance, the second criterion we consider in
assigning a listing priority is the immediacy of threats. This
criterion is intended to ensure that the species facing actual,
identifiable threats are given priority over those for which threats
are only potential or that are intrinsically vulnerable but are not
known to be presently facing such threats. We have factual information
the threats imminent because we have factual information that the
threats are identifiable and that the DPS is currently facing them in
many areas of its range. In particular these actual, identifiable
threats are covered in great detail in factor A of this finding and
include habitat fragmentation and destruction due to urbanization,
infrastructure (e.g. fences, powerlines, and roads), mining, energy
development, grazing, invasive and exotic species, pinyon-juniper
encroachment, recreation, and wildfire. Therefore, based on our LPN
Policy the threats are imminent (ongoing).
The third criterion in our LPN guidance is intended to devote
resources to those species representing highly distinctive or isolated
gene pools as reflected by taxonomy. We have determined the Bi-State
greater sage-grouse population to be a valid DPS according to our DPS
Policy. Therefore under our LPN guidance, the Bi-State DPS of the
greater sage-grouse is assigned a lower priority than a species in a
monotypic genus or a full species that faces the same magnitude and
imminence of threats.
Therefore, we assigned the Bi-State DPS of the greater sage-grouse
an LPN of 3 based on our determination that the DPS faces threats that
are overall of high magnitude and are imminent (i.e. ongoing). We will
continue to monitor the threats to the Bi-State DPS of the greater
sage-grouse, and the DPS' status
[[Page 14010]]
on an annual basis, and should the magnitude or the imminence of the
threats change, we will re-visit our assessment of LPN.
Because we assigned the Bi-State DPS of the greater sage-grouse an
LPN of 3, work on a proposed listing determination for this DPS is
precluded by work on higher priority candidate species (i.e., entities
with LPN of 2 or lower); listing actions with absolute statutory, court
ordered, or court-approved deadlines; and completion of listing
determinations for those species for which work already has been
initiated but is not yet completed. This work includes all the actions
listed in the tables below under expeditious progress (see Tables 13
and 14).
As explained above, a determination that listing is warranted but
precluded also must demonstrate that expeditious progress is being made
to add or remove qualified species to and from the Lists of Endangered
and Threatened Wildlife and Plants. (Although we do not discuss it in
detail here, we also are making expeditious progress in removing
species from the list under the Recovery Program, which is funded by a
separate line item in the budget of the Endangered Species Program. As
explained above in our description of the statutory cap on Listing
Program funds, the Recovery Program funds and actions supported by them
cannot be considered in determining expeditious progress made in the
Listing Program.) As with our ``precluded'' finding, expeditious
progress in adding qualified species to the Lists is a function of the
resources available and the competing demands for those funds. Given
that limitation, we find that we are making progress in FY 2010 in the
Listing Program. This progress included preparing and publishing the
following determinations (Table 13):
Table 13--Fiscal year 2010 completed listing actions.
----------------------------------------------------------------------------------------------------------------
Publication Date Title Actions FR Pages
----------------------------------------------------------------------------------------------------------------
10/08/2009 Listing Lepidium Final Listing 74 FR 52013-52064
papilliferum Threatened
(Slickspot
Peppergrass) as a
Threatened Species
Throughout Its Range...
----------------------------------------------------------------------------------------------------------------
10/27/2009 90-day Finding on a Notice of 90-day 74 FR 55177-55180
Petition To List the Petition Finding, Not
American Dipper in the substantial
Black Hills of South
Dakota as Threatened
or Endangered
----------------------------------------------------------------------------------------------------------------
10/28/2009 Status Review of Arctic Notice of Intent to 74 FR 55524-55525
Grayling (Thymallus Conduct Status
arcticus) in the Upper Review.................
Missouri River System
----------------------------------------------------------------------------------------------------------------
11/03/2009 Listing the British Proposed Listing 74 FR 56757-56770
Columbia Distinct Threatened
Population Segment of
the Queen Charlotte
Goshawk Under the
Endangered Species
Act: Proposed rule.
----------------------------------------------------------------------------------------------------------------
11/03/2009 Listing the Salmon- Proposed Listing 74 FR 56770-56791
Crested Cockatoo as Threatened
Threatened Throughout
Its Range with Special
Rule.
----------------------------------------------------------------------------------------------------------------
11/23/2009 Status Review of Notice of Intent to 74 FR 61100-61102
Gunnison sage-grouse Conduct Status
(Centrocercus minimus) Review.................
----------------------------------------------------------------------------------------------------------------
12/03/2009 12-Month Finding on a Notice of 12 month 74 FR 63343-63366
Petition to List the petition finding, Not
Black-tailed Prairie warranted
Dog as Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
12/03/2009 90-Day Finding on a Notice of 90-day 74 FR 63337-63343
Petition to List Petition Finding,
Sprague's Pipit as Substantial............
Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
12/15/2009 90-Day Finding on Notice of 90-day 74 FR 66260-66271
Petitions To List Nine Petition Finding,
Species of Mussels Substantial............
From Texas as
Threatened or
Endangered With
Critical Habitat.
----------------------------------------------------------------------------------------------------------------
12/16/2009 Partial 90-Day Finding Notice of 90-day 74 FR 66865-66905
on a Petition to List Petition Finding, Not
475 Species in the substantial and
Southwestern United Substantial
States as Threatened
or Endangered With
Critical Habitat;
Proposed Rule
----------------------------------------------------------------------------------------------------------------
12/17/2009 12-month Finding on a Notice of 12 month 74 FR 66937-66950
Petition To Change the petition finding,
Final Listing of the Warranted but precluded
Distinct Population
Segment of the Canada
Lynx To Include New
Mexico
----------------------------------------------------------------------------------------------------------------
1/05/2010 Listing Foreign Bird Proposed 75 FR 605-649
Species in Peru and ListingEndangered
Bolivia as Endangered
Throughout Their Range
----------------------------------------------------------------------------------------------------------------
1/05/2010 Listing Six Foreign Proposed 75 FR 286-310
Birds as Endangered ListingEndangered
Throughout Their Range.
----------------------------------------------------------------------------------------------------------------
1/05/2010 Withdrawal of Proposed Proposed rule, 75 FR 310-316
Rule to List Cook's withdrawal
Petrel
----------------------------------------------------------------------------------------------------------------
1/05/2010 Final Rule to List the Final Listing 75 FR 235-250
Galapagos Petrel and Threatened
Heinroth's Shearwater
as Threatened
Throughout Their Ranges
----------------------------------------------------------------------------------------------------------------
[[Page 14011]]
1/20/2010 Initiation of Status Notice of Intent to 75 FR 3190-3191
Review for Agave Conduct Status
eggersiana and Solanum Review.................
conocarpum
----------------------------------------------------------------------------------------------------------------
2/09/2010 12-month Finding on a Notice of 12 month 75 FR 6437-6471
Petition to List the petition finding, Not
American Pika as warranted
Threatened or
Endangered;.
Proposed Rule..........
----------------------------------------------------------------------------------------------------------------
2/25/2010 12-Month Finding on a Notice of 12 month 75 FR 8601-8621
Petition To List the petition finding, Not
Sonoran Desert warranted
Population of the Bald
Eagle as a
Threatened or
Endangered Distinct
Population.
Segment................
----------------------------------------------------------------------------------------------------------------
2/25/2010 Withdrawal of Proposed Withdrawal of Proposed 75 FR 8621-8644
Rule To List the Rule to List
Southwestern Washington/
Columbia River
Distinct Population
Segment of Coastal
Cutthroat Trout
(Oncorhynchus clarki
clarki) as Threatened.
----------------------------------------------------------------------------------------------------------------
Our expeditious progress also includes work on listing actions that
we funded in FY 2010, and for which work is ongoing but not yet
completed to date. These actions are listed below (Table 14). Actions
in the top section of the table are being conducted under a deadline
set by a court. Actions in the middle section of the table are being
conducted to meet statutory timelines, that is, timelines required
under the Act. Actions in the bottom section of the table are high-
priority listing actions. These actions include work primarily on
species with an LPN of 2, and selection of these species is partially
based on available staff resources, and when appropriate, include
species with a lower priority if they overlap geographically or have
the same threats as the species with the high priority. Including these
species together in the same proposed rule results in considerable
savings in time and funding, as compared to preparing separate proposed
rules for each of them in the future.
Table 14--Listing actions funded in fiscal year 2010 but not yet
completed.
------------------------------------------------------------------------
Species Action
------------------------------------------------------------------------
Actions Subject to Court Order/Settlement Agreement
------------------------------------------------------------------------
6 Birds from Eurasia Final listing determination
------------------------------------------------------------------------
Flat-tailed horned lizard Final listing determination
------------------------------------------------------------------------
6 Birds from Peru Proposed listing
determination
------------------------------------------------------------------------
Sacramento splittail Proposed listing
determination
------------------------------------------------------------------------
Mono basin sage-grouse 12-month petition finding
------------------------------------------------------------------------
Greater sage-grouse 12-month petition finding
------------------------------------------------------------------------
Big Lost River whitefish 12-month petition finding
------------------------------------------------------------------------
White-tailed prairie dog 12-month petition finding
------------------------------------------------------------------------
Gunnison sage-grouse 12-month petition finding
------------------------------------------------------------------------
Wolverine 12-month petition finding
------------------------------------------------------------------------
Arctic grayling 12-month petition finding
------------------------------------------------------------------------
Agave eggergsiana 12-month petition finding
------------------------------------------------------------------------
Solanum conocarpum 12-month petition finding
------------------------------------------------------------------------
Mountain plover 12-month petition finding
------------------------------------------------------------------------
Hermes copper butterfly 90-day petition finding
------------------------------------------------------------------------
Thorne's hairstreak butterfly 90-day petition finding
------------------------------------------------------------------------
Actions with Statutory Deadlines
------------------------------------------------------------------------
48 Kauai species Final listing determination
------------------------------------------------------------------------
[[Page 14012]]
Casey's June beetle Final listing determination
------------------------------------------------------------------------
Georgia pigtoe, interrupted rocksnail, Final listing determination
and rough hornsnail
------------------------------------------------------------------------
2 Hawaiian damselflies Final listing determination
------------------------------------------------------------------------
African penguin Final listing determination
------------------------------------------------------------------------
3 Foreign bird species (Andean flamingo, Final listing determination
Chilean woodstar, St. Lucia forest
thrush)
------------------------------------------------------------------------
5 Penguin species Final listing determination
------------------------------------------------------------------------
Southern rockhopper penguin - Campbell Final listing determination
Plateau population
------------------------------------------------------------------------
5 Bird species from Colombia and Ecuador Final listing determination
------------------------------------------------------------------------
7 Bird species from Brazil Final listing determination
------------------------------------------------------------------------
Queen Charlotte goshawk Final listing determination
------------------------------------------------------------------------
Salmon crested cockatoo Proposed listing
determination
------------------------------------------------------------------------
Black-footed albatross 12-month petition finding
------------------------------------------------------------------------
Mount Charleston blue butterfly 12-month petition finding
------------------------------------------------------------------------
Least chub\1\ 12-month petition finding
------------------------------------------------------------------------
Mojave fringe-toed lizard\1\ 12-month petition finding
------------------------------------------------------------------------
Pygmy rabbit (rangewide)\1\ 12-month petition finding
------------------------------------------------------------------------
Kokanee - Lake Sammamish population\1\ 12-month petition finding
------------------------------------------------------------------------
Delta smelt (uplisting) 12-month petition finding
------------------------------------------------------------------------
Cactus ferruginous pygmy-owl\1\ 12-month petition finding
------------------------------------------------------------------------
Tucson shovel-nosed snake\1\ 12-month petition finding
------------------------------------------------------------------------
Northern leopard frog 12-month petition finding
------------------------------------------------------------------------
Tehachapi slender salamander 12-month petition finding
------------------------------------------------------------------------
Coqui Llanero 12-month petition finding
------------------------------------------------------------------------
Susan's purse-making caddisfly 12-month petition finding
------------------------------------------------------------------------
White-sided jackrabbit 12-month petition finding
------------------------------------------------------------------------
Jemez Mountains salamander 12-month petition finding
------------------------------------------------------------------------
Dusky tree vole 12-month petition finding
------------------------------------------------------------------------
Eagle Lake trout\1\ 12-month petition finding
------------------------------------------------------------------------
29 of 206 species 12-month petition finding
------------------------------------------------------------------------
Desert tortoise - Sonoran population 12-month petition finding
------------------------------------------------------------------------
Gopher tortoise - eastern population 12-month petition finding
------------------------------------------------------------------------
Amargosa toad 12-month petition finding
------------------------------------------------------------------------
Wyoming pocket gopher 12-month petition finding
------------------------------------------------------------------------
Pacific walrus 12-month petition finding
------------------------------------------------------------------------
Wrights marsh thistle 12-month petition finding
------------------------------------------------------------------------
67 of 475 southwest species 12-month petition finding
------------------------------------------------------------------------
[[Page 14013]]
9 Southwest mussel species 12-month petition finding
------------------------------------------------------------------------
14 parrots (foreign species) 12-month petition finding
------------------------------------------------------------------------
Southeastern pop snowy plover & wintering 90-day petition finding
pop. of piping plover\1\
------------------------------------------------------------------------
Eagle Lake trout\1\ 90-day petition finding
------------------------------------------------------------------------
Berry Cave salamander\1\ 90-day petition finding
------------------------------------------------------------------------
Ozark chinquapin\1\ 90-day petition finding
------------------------------------------------------------------------
Smooth-billed ani\1\ 90-day petition finding
------------------------------------------------------------------------
Bay Springs salamander\1\ 90-day petition finding
------------------------------------------------------------------------
Mojave ground squirrel\1\ 90-day petition finding
------------------------------------------------------------------------
32 species of snails and slugs\1\ 90-day petition finding
------------------------------------------------------------------------
Calopogon oklahomensis\1\ 90-day petition finding
------------------------------------------------------------------------
Striped newt\1\ 90-day petition finding
------------------------------------------------------------------------
Southern hickorynut\1\ 90-day petition finding
------------------------------------------------------------------------
42 snail species 90-day petition finding
------------------------------------------------------------------------
White-bark pine 90-day petition finding
------------------------------------------------------------------------
Puerto Rico harlequin 90-day petition finding
------------------------------------------------------------------------
Fisher - Northern Rocky Mtns. population 90-day petition finding
------------------------------------------------------------------------
Puerto Rico harlequin butterfly\1\ 90-day petition finding
------------------------------------------------------------------------
42 snail species (Nevada & Utah) 90-day petition finding
------------------------------------------------------------------------
HI yellow-faced bees 90-day petition finding
------------------------------------------------------------------------
Red knot roselaari subspecies 90-day petition finding
------------------------------------------------------------------------
Honduran emerald 90-day petition finding
------------------------------------------------------------------------
Peary caribou 90-day petition finding
------------------------------------------------------------------------
Western gull-billed tern 90-day petition finding
------------------------------------------------------------------------
Plain bison 90-day petition finding
------------------------------------------------------------------------
Giant Palouse earthworm 90-day petition finding
------------------------------------------------------------------------
Mexican gray wolf 90-day petition finding
------------------------------------------------------------------------
Spring Mountains checkerspot butterfly 90-day petition finding
------------------------------------------------------------------------
Spring pygmy sunfish 90-day petition finding
------------------------------------------------------------------------
San Francisco manzanita 90-day petition finding
------------------------------------------------------------------------
Bay skipper 90-day petition finding
------------------------------------------------------------------------
Unsilvered fritillary 90-day petition finding
------------------------------------------------------------------------
Texas kangaroo rat 90-day petition finding
------------------------------------------------------------------------
Spot-tailed earless lizard 90-day petition finding
------------------------------------------------------------------------
Eastern small-footed bat 90-day petition finding
------------------------------------------------------------------------
Northern long-eared bat 90-day petition finding
------------------------------------------------------------------------
Prairie chub 90-day petition finding
------------------------------------------------------------------------
[[Page 14014]]
10 species of Great Basin butterfly 90-day petition finding
------------------------------------------------------------------------
.............................
------------------------------------------------------------------------
High Priority Listing Actions\3\
------------------------------------------------------------------------
19 Oahu candidate species\3\ (16 plants, Proposed listing
3 damselflies) (15 with LPN = 2, 3 with
LPN = 3, 1 with LPN =9)
------------------------------------------------------------------------
17 Maui-Nui candidate species\3\ (14 Proposed listing
plants, 3 tree snails) (12 with LPN = 2,
2 with LPN = 3, 3 with LPN = 8)
------------------------------------------------------------------------
Sand dune lizard\3\ (LPN = 2) Proposed listing
------------------------------------------------------------------------
2 Arizona springsnails\3\ (Pyrgulopsis Proposed listing
bernadina (LPN = 2), Pyrgulopsis
trivialis (LPN = 2))
------------------------------------------------------------------------
2 New Mexico springsnails\3\ (Pyrgulopsis Proposed listing
chupaderae (LPN = 2), Pyrgulopsis
thermalis (LPN = 11))
------------------------------------------------------------------------
2 mussels\3\ (rayed bean (LPN = 2), Proposed listing
snuffbox No LPN)
------------------------------------------------------------------------
2 mussels\3\ (sheepnose (LPN = 2), Proposed listing
spectaclecase (LPN = 4),)
------------------------------------------------------------------------
Ozark hellbender\2\ (LPN = 3) Proposed listing
------------------------------------------------------------------------
Altamaha spinymussel\3\ (LPN = 2) Proposed listing
------------------------------------------------------------------------
5 southeast fish\3\ (rush darter (LPN = Proposed listing
2), chucky madtom (LPN = 2), yellowcheek
darter (LPN = 2), Cumberland darter (LPN
= 5), laurel dace (LPN = 5))
------------------------------------------------------------------------
8 southeast mussels (southern kidneyshell Proposed listing
(LPN = 2), round ebonyshell (LPN = 2),
Alabama pearlshell (LPN = 2), southern
sandshell (LPN = 5), fuzzy pigtoe (LPN =
5), Choctaw bean (LPN = 5), narrow
pigtoe (LPN = 5), and tapered pigtoe
(LPN = 11))
------------------------------------------------------------------------
3 Colorado plants\3\ (Pagosa skyrocket Proposed listing
(Ipomopsis polyantha) (LPN = 2),
Parachute beardtongue (Penstemon
debilis) (LPN = 2), Debeque phacelia
(Phacelia submutica) (LPN = 8))
------------------------------------------------------------------------
\1\ Funds for listing actions for these species were provided in
previous FYs.
\2\ We funded a proposed rule for this subspecies with an LPN of 3 ahead
of other species with LPN of 2, because the threats to the species
were so imminent and of a high magnitude that we considered emergency
listing if we were unable to fund work on a proposed listing rule in
FY 2008.
\3\ Funds for these high-priority listing actions were provided in FY
2008 or 2009
We have endeavored to make our listing actions as efficient and
timely as possible, given the requirements of the relevant laws and
regulations, and constraints relating to workload and personnel. We are
continually considering ways to streamline processes or achieve
economies of scale, such as by batching related actions together. Given
our limited budget for implementing section 4 of the Act, the actions
described above collectively constitute expeditious progress.
The greater sage-grouse and the Bi-State DPS of the greater sage-
grouse will each be added to the list of candidate species upon
publication of these 12-month findings. We will continue to monitor
their status as new information becomes available. This review will
determine if a change in status is warranted, including the need to
make prompt use of emergency listing procedures. We acknowledge we must
reevaluate the status of the Columbia Basin population as it relates to
the greater sage-grouse; we will conduct this analysis as our
priorities allow. Other populations of the greater sage-grouse, as
appropriate, will be evaluated to determine if they meet the distinct
population segment (DPS) policy prior to a listing action, if necessary
and appropriate.
We intend that any proposed listing action for the greater sage-
grouse or Bi-State DPS of the greater sage-grouse will be as accurate
as possible. Therefore, we will continue to accept additional
information and comments from all concerned governmental agencies, the
scientific community, industry, or any other interested party
concerning these findings.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Wyoming Ecological
Services Office (see ADDRESS section).
Author
The primary authors of this notice are the staff members of the
Wyoming, Montana, Idaho, Nevada, and Oregon Ecological Services
Offices.
Authority: The authority for this section is section 4 of the
Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: March 3, 2010
Daniel M Ashe,
Acting Director, Fish and Wildlife Service
[FR Doc. 2010-5132 Filed 3-22- 10; 8:45 am]
BILLING CODE 4310-55-S