[Federal Register Volume 74, Number 154 (Wednesday, August 12, 2009)]
[Proposed Rules]
[Pages 40650-40683]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-18691]
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Part II
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; Listing Seven Brazilian
Bird Species as Endangered Throughout Their Range; Proposed Rule
Federal Register / Vol. 74, No. 154 / Wednesday, August 12, 2009 /
Proposed Rules
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R9-IA-2009-0028; 96100-1671-0000-B6]
RIN 1018-AV74
Endangered and Threatened Wildlife and Plants; Listing Seven
Brazilian Bird Species as Endangered Throughout Their Range
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to
list the following seven Brazilian bird species and subspecies
(collectively referred to as ``species'' for purposes of this proposed
rule) as endangered under the Endangered Species Act of 1973, as
amended (Act) (16 U.S.C. 1531 et seq.): black-hooded antwren
(Formicivora erythronotos), Brazilian merganser (Mergus octosetaceus),
cherry-throated tanager (Nemosia rourei), fringe-backed fire-eye
(Pyriglena atra), Kaempfer's tody-tyrant (Hemitriccus kaempferi),
Margaretta's hermit (Phaethornis malaris margarettae), and southeastern
rufous-vented ground-cuckoo (Neomorphus geoffroyi dulcis). This
proposal, if made final, would extend the Act's protection to these
species. The Service seeks data and comments from the public on this
proposed rule.
DATES: We will accept comments received or postmarked on or before
October 13, 2009. We must receive requests for public hearings, in
writing, at the address shown in the FOR FURTHER INFORMATION CONTACT
section by September 28, 2009.
ADDRESSES: You may submit comments by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the instructions for submitting comments.
U.S. mail or hand-delivery: Public Comments Processing,
Attn: FWS-R9-IA-2009-0028; Division of Policy and Directives
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive,
Suite 222; Arlington, VA 22203.
We will post all comments on http://www.regulations.gov. This
generally means that we will post any personal information you provide
us (see the Public Comments section below for more information).
FOR FURTHER INFORMATION CONTACT: Douglas Krofta, Chief, Branch of
Listing, Endangered Species Program, U.S. Fish and Wildlife Service,
4401 N. Fairfax Drive, Room 420, Arlington, VA 22203; telephone 703-
358-2105; facsimile 703-358-1735. If you use a telecommunications
device for the deaf (TDD), call the Federal Information Relay Service
(FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Public Comments
We intend that any final action resulting from this proposal will
be as accurate and as effective as possible. Therefore, we request
comments or suggestions on this proposed rule. We particularly seek
comments concerning:
(1) Biological, commercial trade, or other relevant data concerning
any threats (or lack thereof) to these species and regulations that may
be addressing those threats.
(2) Additional information concerning the taxonomy, range,
distribution, and population size of these species, including the
locations of any additional populations of these species.
(3) Any information on the biological or ecological requirements of
these species.
(4) Current or planned activities in the areas occupied by these
species and possible impacts of these activities on these species.
(5) Any information concerning the effects of climate change on
these species or their habitats.
You may submit your comments and materials concerning this proposed
rule by one of the methods listed in the ADDRESSES section. We will not
consider comments sent by e-mail or fax or to an address not listed in
the ADDRESSES section.
If you submit a comment via http://www.regulations.gov, your entire
comment--including any personal identifying information--will be posted
on the Web site. If you submit a hardcopy comment that includes
personal identifying information, you may request at the top of your
document that we withhold this information from public review. However,
we cannot guarantee that we will be able to do so. We will post all
hardcopy comments on http://www.regulations.gov.
Comments and materials we receive, as well as supporting
documentation we used in preparing this proposed rule, will be
available for public inspection on http://www.regulations.gov, or by
appointment, during normal business hours, at the U.S. Fish and
Wildlife Service, Endangered Species Program, 4401 N. Fairfax Drive,
Room 420, Arlington, VA 22203; telephone 703-358-2171.
Background
Section 4(b)(3)(A) of the Act requires us to make a finding (known
as a ``90-day finding'') on whether a petition to add a species to,
remove a species from, or reclassify a species on the Federal Lists of
Endangered and Threatened Wildlife and Plants has presented substantial
information indicating that the requested action may be warranted. To
the maximum extent practicable, the finding must be made within 90 days
following receipt of the petition and must be published promptly in the
Federal Register. If we find that the petition has presented
substantial information indicating that the requested action may be
warranted (a positive finding), section 4(b)(3)(A) of the Act requires
us to commence a status review of the species if one has not already
been initiated under our internal candidate assessment process. In
addition, section 4(b)(3)(B) of the Act requires us to make a finding
within 12 months following receipt of the petition (``12-month
finding'') on whether the requested action is warranted, not warranted,
or warranted but precluded by higher priority listing. Section
4(b)(3)(C) of the Act requires that a finding of warranted but
precluded for petitioned species should be treated as having been
resubmitted on the date of the warranted but precluded finding, and is,
therefore, subject to a new finding within 1 year and subsequently
thereafter until we publish a proposal to list or a finding that the
petitioned action is not warranted. The Service publishes an annual
notice of resubmitted petition findings (annual notice) for all foreign
species for which listings were previously found to be warranted but
precluded.
The following seven Brazilian bird species are addressed in this
proposed rule: Black-hooded antwren (Formicivora erythronotos),
previously recognized under the genus Myrmotherula; Brazilian merganser
(Mergus octosetaceus); cherry-throated tanager (Nemosia rourei);
fringe-backed fire-eye (Pyriglena atra), previously referred to as
Swainson's fire-eye; Kaempfer's tody-tyrant (Hemitriccus kaempferi),
previously recognized under the genus Idioptilon; Margaretta's hermit
(Phaethornis malaris margarettae), previously referred to as the Klabin
Farm long-tailed hermit and recognized at the species level as P.
margarettae; and southeastern rufous-vented ground-cuckoo (Neomorphus
geoffroyi dulcis). All of the above species are found in the Atlantic
Forest and neighboring regions of southeastern Brazil.
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We are addressing the seven Brazilian bird species identified above
under a single proposed rule primarily for three reasons. First, all of
these species are found in the Atlantic Forest and neighboring regions
of southeastern Brazil, thus addressing them together makes sense from
a regional conservation perspective. Second, these seven species are
subject to similar threats of comparable magnitude, primarily the loss
and degradation of habitat due to deforestation and other ongoing
development practices affecting southeastern Brazil, as well as
concomitant threats due to severely restricted distributions and small
population sizes (such as potential loss of genetic viability).
Combining species that face similar threats within the same general
geographic area into one proposed rule allows us to maximize our
limited staff resources, thus increasing our ability to complete the
listing process for warranted-but-precluded species.
Previous Federal Actions
On November 28, 1980, we received a petition (the 1980 petition)
from Dr. Warren B. King, Chairman, United States Section of the
International Council for Bird Preservation (ICBP), to add 60 foreign
bird species to the List of Endangered and Threatened Wildlife (50 CFR
17.11(h)), including 5 of the 7 Brazilian bird species (black-hooded
antwren, cherry-throated tanager, fringe-backed fire-eye, Margaretta's
hermit, and southeastern rufous-vented ground-cuckoo) that are the
subject of this proposed rule. Two of the foreign species identified in
the petition were already listed under the Act; therefore, in response
to the 1980 petition, we published a substantial 90-day finding on May
12, 1981 (46 FR 26464), for 58 foreign species and initiated a status
review. On January 20, 1984 (49 FR 2485), we published a 12-month
finding within an annual review on pending petitions and description of
progress on all pending petition findings. In that notice, we found
that all 58 foreign bird species from the 1980 petition were warranted
but precluded by higher priority listing actions. On May 10, 1985, we
published the first annual notice (50 FR 19761) in which we continued
to find that listing all 58 foreign bird species from the 1980 petition
was warranted but precluded. We published additional annual notices on
the 58 species included in the 1980 petition on January 9, 1986 (51 FR
996), July 7, 1988 (53 FR 25511), December 29, 1988 (53 FR 52746),
April 25, 1990 (55 FR 17475), November 21, 1991 (56 FR 58664), and May
21, 2004 (69 FR 29354). These notices indicated that the black-hooded
antwren, cherry-throated tanager, fringe-backed fire-eye, Margaretta's
hermit, and southeastern rufous-vented ground-cuckoo, along with the
remaining species in the 1980 petition, continued to be warranted but
precluded.
On May 6, 1991, we received a second petition (the 1991 petition)
from ICBP to add an additional 53 foreign bird species to the List of
Endangered and Threatened Wildlife, including the 2 remaining Brazilian
bird species (Brazilian merganser and Kaempfer's tody-tyrant) that are
the subject of this proposed rule. In response to the 1991 petition, we
published a substantial 90-day finding on December 16, 1991 (56 FR
65207), for all 53 species and initiated a status review. On March 28,
1994 (59 FR 14496), we published a 12-month finding on the 1991
petition, along with a proposed rule to list 30 African birds under the
Act (15 each from the 1980 petition and 1991 petition). In that
document, we announced our finding that listing the remaining 38
species from the 1991 petition, including the Brazilian merganser and
Kaempfer's tody-tyrant, was warranted but precluded by higher priority
listing actions. We made a subsequent warranted-but-precluded finding
for all outstanding foreign species from the 1980 and 1991 petitions,
including the seven Brazilian bird species that are the subject of this
proposed rule, as published in our annual notice of review (ANOR) on
May 21, 2004 (69 FR 29354).
Per the Service's listing priority guidelines (September 21, 1983;
48 FR 43098), our 2007 ANOR identified the listing priority numbers
(LPNs) (ranging from 1 to 12) for all outstanding foreign species. The
LPNs for the seven Brazilian bird species that are the subject of this
proposed rule are as follows: The black-hooded antwren, Brazilian
merganser, cherry-throated tanager, fringe-backed fire-eye, and
Kaempfer's tody-tyrant (LPN 2); and the Margaretta's hermit and
southeastern rufous-vented ground-cuckoo (LPN 3). Listing priorities of
2 and 3 indicate that the subject species and subspecies, respectively,
face imminent threats of high magnitude. With the exception of listing
priority ranking of 1, which addresses monotypic genera that face
imminent threats of high magnitude, categories 2 and 3 represent the
Service's highest priorities.
On July 29, 2008 (73 FR 44062), we published in the Federal
Register a notice announcing our annual petition findings for foreign
species. In that notice, we announced listing to be warranted for 30
foreign bird species, including the seven Brazilian bird species which
are the subject of this proposed rule, and stated that we would
``promptly publish proposals to list these 30 taxa.''
On September 8, 2008, the Service received a 60-day notice of
intent to sue from the Center for Biological Diversity (CBD) over
violations of section 4 of the Act for the Service's failure to
promptly publish listing proposals for the 30 ``warranted'' species
identified in our 2008 ANOR. Under a settlement agreement approved by
the U.S. District Court for the Northern District of California on June
15, 2009, (CDB v. Salazar, 09-cv-02578-CRB), the Service must submit to
the Federal Register proposed listing rules for the black-hooded
antwren, Brazilian merganser, cherry-throated tanager, fringe-backed
fire-eye, Kaempfer's tody-tyrant, Margaretta's hermit, and southeastern
rufous-vented ground-cuckoo by July 31, 2009.
Species Information and Factors Affecting the Species
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. A species may be determined to be an endangered or threatened
species due to one or more of the five factors described in section
4(a)(1) of the Act. The five factors are: (A) The present or threatened
destruction, modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; and (E) other natural or manmade
factors affecting its continued existence. Listing actions may be
warranted based on any of the above threat factors, singly or in
combination.
If we consider that wildlife habitat is not only defined by
substrates (vegetation, soil, water), but also atmospheric conditions,
then changes in air temperature and moisture can effectively change a
species' habitat. Climate change is characterized by variations in the
earth's temperature and precipitation causing changes in atmospheric,
oceanic, and terrestrial conditions (Parmesan and Mathews 2005, p.
334). Global climate change and other periodic climatic patterns (e.g.,
El Ni[ntilde]o and La Ni[ntilde]a) can cause or exacerbate such
negative impacts on a broad range of terrestrial ecosystems and
neotropical bird populations (Crick 2004, p. 1; England 2000, p. 86;
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Holmgren et al. 2001, p. 89; Plumart 2007, pp. 1-2). For example, trees
cool their area of influence through high rates of evapotranspiration,
or water loss to the atmosphere from their leaves (Parmesan and Mathews
2005, p. 337). Areas where trees have been replaced with pastures have
lower evapotranspiration rates, thus causing local areas to be warmer
(Parmesan and Mathews 2005, p. 337). According to the Intergovernmental
Panel on Climate Change (IPCC), climate change can contribute to
modifications of Amazonian rainforest habitats that are affected by
deforestation (IPCC 1997, p. 11). Parmesan and Mathews (2005, p. 373)
suggest that climate change is more likely to cause range reductions
rather than range shifts. This may be due to the lack of areas where a
species could shift to or the spaces between habitat patches are too
large for individuals to reach. This suggests that climate change could
be an agent of habitat loss or modification.
Despite the fact that global climate changes are occurring and
affecting habitat, the climate change models that are currently
available are not yet able to make meaningful predictions of climate
change for specific, local areas (Parmesan and Matthews 2005, p. 354),
such as the Atlantic Forest and Cerrado (savanna) bioregions. In
addition, we do not have models to predict how the climate in the range
of these Brazilian bird species will change, and we do not know how any
change that may occur, would affect these species. We also do not have
information on past and future weather patterns within the specific
range of these species. Therefore, based on the current lack of
information and data, we did not evaluate climate change as a threat to
these species. We are, however, seeking additional information on this
subject (see Public Comments) that can be used in preparing the final
rule.
Below is a species-by-species analysis of the five factors. The
species are considered in alphabetical order, beginning with the black-
hooded antwren, followed by the Brazilian merganser, cherry-throated
tanager, fringe-backed fire-eye, Kaempfer's tody-tyrant, Margaretta's
hermit, and the southeastern rufous-vented ground-cuckoo.
I. Black-hooded Antwren (Formicivora erythronotos)
Species Description
The black-hooded antwren measures 10.5 to 11.5 centimeters (cm) (4
to 4.5 inches (in)) (BirdLife International (BLI) 2007d, p. 1; Sisk
1993, p. 414). Males are black with a reddish-brown back. They have a
black narrow bill and a long tail. There are three thin white stripes
on the wings. Females have similar coloring, except they have brown-
olive feathers where black feathers appear on males (BLI 2007d, p. 1).
Taxonomy
The black-hooded antwren is a small member of the diverse
``antbird'' family (Thamnophilidae). The species was previously
recognized under the genus Myrmotherula (BLI 2007d, p. 1; Collar et al.
1992, p. 667; Sick 1993, p. 414).
Habitat and Life History
The Atlantic Forest biome encompasses a region of tropical and
subtropical moist forests, tropical dry forests, and mangrove forests,
that extend along the Atlantic coast of Brazil from Rio Grande do Norte
in the north to Rio Grande do Sul in the south, and inland as far as
Paraguay and Misiones Province of northeastern Argentina (Conservation
International 2007a, p. 1; H[ouml]fling 2007, p. 1; Morellato and
Haddad 2000, pp. 786-787). The black-hooded antwren inhabits lush
understories of remnant old-growth and early successional secondary-
growth coastal forests, and it may also occur in dense understories of
modified ``restinga,'' (``restinga'' is a Brazilian term that describes
a patchwork of vegetation types consisting of beach vegetation, open
shrubby vegetation, and dry and swamp forests distributed over coastal
plains from northeastern to southeastern Brazil (McGinley 2007, pp. 1-
2)), swampy woodlands, abandoned banana plantations, and eucalyptus
stands (BLI 2007d, p. 1; Tobias and Williams 1996, p. 64).
Although the specific habitat requirements of the black-hooded
antwren are still unclear, the species is not considered a tropical
forest specialist. The black-hooded antwren typically forages in pairs
or small family groups and consumes various insects, spiders, and small
frogs (Collar et al. 1992, p. 667; del Hoyo 2003, p. 616; Sick 1993, p.
405; Tobias and Williams 1996, p. 65). Black-hooded antwrens usually
forage in dense vegetation within approximately 3 meters (m) (10 feet
(ft)) of the ground, but they are also known to feed higher up (ca. 7 m
(23 ft)).
Females typically lay two eggs in fragile nests resembling small
cups made of plant material (e.g., rootlets, stems, moss) that are
attached to horizontal branches within roughly 1 m (3.3 ft) of the
ground (Collar et al. 1992, p. 667; Sick 1993, p. 405). Both sexes help
to build the nests, brood clutches, and attend their young.
Range and Distribution
The black-hooded antwren is endemic to the Atlantic Forest biome in
the southeast of the state of Rio de Janeiro (BLI 2007d, p. 1; Collar
et al. 1992, p. 667). Currently, the only confirmed population is
believed to be restricted to remnant patches of forest habitat along
roughly 30 kilometers (km) (19 miles (mi)) of coast in southern Rio de
Janeiro, near the border with S[atilde]o Paulo (Browne 2005, p. 95;
Tobias and Williams 1996, p. 64). However, there have also been recent
unconfirmed reports that the species may occur at the state Ecological
Reserve of Jacarepi[aacute], located roughly 75 km (47 mi) northeast of
the city of Rio de Janeiro (ADEJA 2007, p. 3; WorldTwitch 2007, p. 12).
Population Estimates
The black-hooded antwren was known from 20 specimens that were
purportedly collected in the 1800s in montane forest habitats of
central Rio de Janeiro, Brazil. The species had not been reported since
that collection until it was rediscovered in 1987 in the Atlantic
forest in south Rio de Janeiro (BLI 2007d, p. 1).
The extant population is estimated to be between 1,000 and 2,499
birds, and is fragmented among seven occupied sites, including
Bracu[iacute], Frade, S[atilde]o Gon[ccedil]alo, Taquari and Barra
Grande, Arir[oacute], and Vale do Mambucaba. Vale do Mambucaba has the
highest known density of pairs (156 pairs per square kilometer
(km\2\)), followed by Mambucaba (densities of 89 pairs/km\2\). There
are no known estimates for the other locations, but it is believed that
the numbers are few (BLI 2007d, p. 1). At least one of the fragmented
populations is believed to be reproductively isolated. The population,
as a whole, is also believed to be declining rapidly due to continued
loss of habitat (BLI 2007d, pp. 1-3).
Conservation Status
The IUCN considers the black-hooded antwren to be ``Endangered''
because ``it has a very small and severely fragmented range that is
likely to be declining rapidly in response to habitat loss'' (BLI
2007d, p. 3). The species is also protected by Brazilian law and occurs
in the buffer area of Serra da Boca[iacute]na National Park (BLI 2007d,
p. 2).
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Summary of Factors Affecting the Black-hooded Antwren
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Based on a number of recent estimates, 92 to 95 percent of the area
historically covered by tropical forests within the Atlantic Forest
biome has been converted or severely degraded as a result of various
human activities (Butler 2007, p. 2; Conservation International 2007a,
p. 1; H[ouml]fling 2007, p. 1; Morellato and Haddad 2000, p. 786; Myers
et al. 2000, pp. 853-854; The Nature Conservancy 2007, p. 1; Saatchi et
al. 2001, p. 868; World Wildlife Fund 2007, pp. 2-41). In addition to
the overall loss and degradation of native habitats within this biome,
the remaining tracts of habitat are severely fragmented. The current
rate of habitat decline is unknown.
The region has the two largest cities in Brazil, S[atilde]o Paulo
and Rio de Janeiro, and is home to approximately 70 percent of Brazil's
169 million people (CEPF 2002; IBGE 2007). The major human activities
that have resulted in the loss, degradation, and fragmentation of
native habitats within the Atlantic Forest biome include extensive
establishment of agricultural fields (e.g., soy beans, sugarcane,
corn), plantations (e.g., eucalyptus, pine, coffee, cocoa, rubber,
bananas), livestock pastures, centers of human habitation, and
industrial developments (e.g., charcoal production, steel plants,
hydropower reservoirs). Forestry practices (e.g., commercial logging,
subsistence activities, fuelwood collection) and changes in fire
frequencies (BLI 2003a, p. 4; J[uacute]nior et al. 1995, p. 147; The
Nature Conservancy 2007, p. 2; Nunes and Kraas 2000, p. 44; Peixoto and
Silva 2007, p. 5; Saatchi et al. 2001, pp. 868-869; Scott and Brooke
1985, p. 118; World Wildlife Fund 2007, pp. 3-51) also contribute to
the degradation of native habitat.
The black-hooded antwren is not strictly tied to primary forest
habitats and can make use of secondary-growth forests or other
disturbed areas, such as modified ``restinga,'' eucalyptus stands,
abandoned banana plantations, and recently burned sites (BLI 2007d, p.
1; Tobias and Williams 1996, p. 64). However, this does not necessarily
lessen the threat to the species from the effects of deforestation and
habitat degradation. Atlantic Forest birds, such as the black-hooded
antwren, which are tolerant of secondary-growth forests or other
disturbed sites, are also rare or have severely restricted ranges
(i.e., less than 21,000 km\2\ (8,100 square miles (mi\2\))). Thus
habitat degradation can adversely impact such species, just as equally
as it impacts primary forest-obligate species (Harris and Pimm 2004,
pp. 1612-1613). While the black-hooded antwren is relatively abundant
locally, the entire range of the species encompasses only about 130
km\2\ (50 mi\2\), with only 45 percent of this area considered occupied
(BLI 2007d, pp. 3-4).
The susceptibility to habitat destruction of limited-range species
that are tolerant of secondary-growth forests or other disturbed sites
can occur for a variety of reasons, such as when a species' remaining
population is already too small or its distribution too fragmented such
that it may not be demographically or genetically viable (Harris and
Pimm 2004, pp. 1612-1613). In addition, while the black-hooded antwren
may be tolerant of secondary-growth forests or other disturbed sites,
these areas may not represent optimal conditions for the species, which
would include dense understories and abundant prey species. For
example, management of plantations often involves intensive control of
the site's understory vegetation and long-term use of pesticides, which
eventually results in severely diminished understory cover and
potential prey species (Rolim and Chiarello 2004, pp. 2687-2691;
Saatchi et al. 2001, pp. 868-869; Scott and Brooke 1985, p. 118). Such
management activities make these sites unsuitable for the black-hooded
antwren (BLI 2007d, p. 2).
Impacts associated with the destruction of native habitat by human
activities within the Atlantic Forest biome include extensive
fragmentation of the remaining tracts of forested habitat potentially
used by the black-hooded antwren (see Factor E). As a secondary impact,
habitat destruction of these remaining tracts increases the potential
introduction of disease vectors or exotic predators within the species'
historic range (see Factor C). Furthermore, even when potentially
occupied sites may be formally protected, such as the state Ecological
Reserve of Jacarepi[aacute] (see Factor D), the remaining fragments of
forested habitat will likely undergo further degradation due to their
altered dynamics and isolation (ADEJA 2007, pp. 1-2; Tabanez and Viana
2000, pp. 929-932). Altered dynamics and isolation are characterized by
a decrease in gene flow and inbreeding, which decrease the fitness of
forest species (Tabanez and Viana 2000, pp. 929-932). In addition,
fragmented Atlantic forests of Brazil are observed to be overtaken by
lianas (long-stemmed woody vines), which cause tree falls and gaps in
the forest structure. These gaps in the forest encourage gap-
opportunistic vegetation to grow. Hence, a decrease in gene flow, and
increases in inbreeding, liana density, and presence of gap-
opportunistic species change the character and dynamics of the Atlantic
Forest biome and isolate fragmented habitat patches (Tabanez and Viana
2000, pp. 930-931). These changes may result in the loss of important
species that comprise the black-hooded antwren habitat. As a result of
these secondary impacts, there is often a time lag between the initial
conversion or degradation of suitable habitats and the extinction of
endemic bird populations (Brooks et al. 1999a, p. 1; Brooks et al.
1999b, p. 1140). Therefore, even without further habitat loss or
degradation, the black-hooded antwren remains at risk from past impacts
to its suitable habitats.
The black-hooded antwren occurs in one of the most densely
populated regions of Brazil, and most of the tropical forest habitats
believed to have been used historically by the species have been
converted or are severely degraded due to the wide range of human
activities identified above (BLI 2003a, p. 4; BLI 2007d, p. 2; Collar
et al. 1992, p. 667; Conservation International 2007a, p. 1; del Hoyo
2003, p. 616; H[ouml]fling 2007, p. 1; The Nature Conservancy 2007, p.
1; World Wildlife Fund 2007, pp. 3-51). In addition, the remaining
tracts of suitable habitat in Rio de Janeiro and S[atilde]o Paulo are
threatened by ongoing development of coastal areas, primarily for
tourism enterprises (e.g., large hotel complexes, beachside housing)
and associated infrastructure support, as well as widespread clearing
for expansion of livestock pastures and plantations, primarily for
Euterpe palms (BLI 2003a, p. 4; BLI 2007d, p. 2; Collar et al. 1992, p.
667; del Hoyo 2003, p. 616; World Wildlife Fund 2007, pp. 7 and 36-37).
These impacts have recently reduced suitable habitats at various key
sites known to be occupied by the black-hooded antwren such as Vale do
Mambucaba and Arir[oacute], and the remaining occupied habitats at
these sites are subject to ongoing human disturbances, such as off-road
vehicle use, burning, and recreational activities (BLI 2007d, p. 2;
Collar et al. 1994, p. 134; del Hoyo 2003, p. 616).
Summary of Factor A
A significant portion of Atlantic Forest habitats have been, and
continue to be, lost and degraded by various ongoing human activities,
including
[[Page 40654]]
logging, establishment and expansion of plantations and livestock
pastures, urban and industrial developments (including many new
hydroelectric dams), slash-and-burn clearing, intentional and
accidental ignition of fires, and establishment of invasive species
(CEPF 2001, pp. 9-15). Even with the recent passage of a national
forest policy and in light of many other legal protections in Brazil
(see Factor D), the rate of habitat loss throughout the Atlantic Forest
biome has increased since the mid-1990s (CEPF 2001, p. 10; Hodge et al.
1997, p. 1; Rocha et al. 2005, p. 270), and native habitats at many of
the remaining sites may be lost over the next several years (Rocha et
al. 2005, p. 263). Furthermore, because the black-hooded antwren's
extant population is already small, highly fragmented, and believed to
be declining (BLI 2007d, pp. 1-3), any further loss or degradation of
its remaining suitable habitat represents a significant threat to the
species (see Factor E). Therefore, we find that destruction and
modification of habitat are threats to the continued existence of the
black-hooded antwren throughout its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The extant population of the black-hooded antwren is considered to
be small, fragmented, and declining. The species was deliberately not
collected when it was rediscovered in 1987 (Collar et al. 1992, p.
667). This is because the removal or dispersal of just a few
individuals from any of the black-hooded antwren's subpopulations or
even a slight decline in their fitness due to intentional or
inadvertent hunting, specimen collection, or other human disturbances
(e.g., scientific research, birding) could represent significant risks
to the species' overall viability (see Factor E). However, while these
potential influences remain a concern for future management of the
species, we are not aware of any other information currently available
that indicates the use of this species for any commercial,
recreational, scientific, or educational purpose. As a result, we are
not considering overutilization to be a contributing factor to the
continued existence of the black-hooded antwren.
C. Disease or Predation
Large, stable populations of wildlife species have adapted to
natural levels of disease and predation within their historic ranges.
However, the extant population of the black-hooded antwren is
considered to be small, fragmented, and declining. In addition,
extensive human activity in previously undisturbed or isolated areas
can lead to the introduction and spread of exotic diseases, some of
which (e.g., West Nile virus) can negatively impact endemic bird
populations (Naugle et al. 2004, p. 704; Neotropical News 2003, p. 1).
Extensive human activity in previously undisturbed or isolated areas
can also result in altered predator populations and the introduction of
various exotic predator species, some of which (e.g., feral cats (Felis
catus) and rats (Ratus sp.)) can be especially harmful to populations
of endemic bird species (American Bird Conservancy 2007, p. 1;
Courchamp et al. 1999, p. 219; Duncan and Blackburn 2007, pp. 149-150;
Salo et al. 2007, pp. 1241-1242; Small 2005, p. 257). Any additive
mortality to the black-hooded antwren's subpopulations or a decrease in
their fitness due to an increase in the incidence of disease or
predation could represent significant threats to the species' overall
viability (see Factor E).
Although disease and predation may be a concern for future
management of the black-hooded antwren, we are not aware of any
species-specific information currently available that indicates that
disease or predation poses a threat to the species. As a result, we are
not considering disease or predation to be a contributing factor to the
continued existence of the black-hooded antwren.
D. The Inadequacy of Existing Regulatory Mechanisms
The black-hooded antwren is formally recognized as ``endangered''
in Brazil (Order No. 1.522) and is directly protected by various laws
promulgated by the Brazilian government (BLI 2007d, p. 2; Collar et al.
1992, p. 667; ECOLEX 2007, pp. 1-2). For example, there are measures
that prohibit, or regulate through Federal agency oversight, the
following activities with regard to endangered species: export and
international trade (e.g., Decree No. 76.623, Order No. 419-P), hunting
(e.g., Act No. 5.197), collection and research (Order No. 332), captive
propagation (Order No. 5), and general harm (e.g., Decree No. 3.179).
In addition, there are a wide range of regulatory mechanisms in Brazil
that indirectly protect the black-hooded antwren through measures that
protect its remaining suitable habitat (ECOLEX 2007, pp. 2-5). For
example, there are measures that: (1) Prohibit exploitation of the
remaining primary forests within the Atlantic Forest biome (e.g.,
Decree No. 750, Resolution No. 10); (2) govern various practices
associated with the management of primary and secondary forests, such
as logging, charcoal production, reforestation, recreation, and water
resources (e.g., Resolution No. 9, Act No. 4.771, Decree No. 1.282,
Decree No. 3.420, Order No. 74-N, Act No. 7.803); (3) establish
provisions for controlling forest fires (e.g., Decree No. 97.635, Order
No. 231-P, Order No. 292-P, Decree No. 2.661); and (4) regulate
industrial developments, such as hydroelectric plants and biodiesel
production (e.g., Normative Instruction No. 65, Law No. 11.116).
Finally, there are various measures (e.g., Law No. 11.516, Act No.
7.735, Decree No. 78, Order No. 1, Act No. 6.938) that direct Federal
and state agencies to promote the protection of lands and natural
resources under their jurisdictions (ECOLEX 2007, pp. 5-6).
There are also various regulatory mechanisms in Brazil that govern
the formal establishment and management of protected areas to promote
conservation of the country's natural resources (ECOLEX 2007, pp. 6-7).
These mechanisms generally aim to protect endangered wildlife and plant
species, genetic resources, overall biodiversity, and native ecosystems
on Federal, state, and privately owned lands (e.g., Law No. 9.985, Law
No. 11.132, Resolution No. 4, Decree No. 1.922). Brazil's formally
established protection areas are categorized based on their overall
management objectives (e.g., National Parks versus Biological
Reserves); and based on those categories, they allow varying uses and
provide varying levels of protection for specific resources (Costa
2007, pp. 5-19).
The black-hooded antwren occurs in the buffer zone around Serra da
Bocaina National Park and, possibly, within Tamoios Environmental
Protection Area and the Ecological Reserve of Jacarepi[aacute] (BLI
2007d, p. 2; del Hoyo 2003, p. 616; WorldTwitch 2007, p. 12). It has
been recommended that some of these sites should be expanded and other
sites designated to ensure the species' currently occupied range is
encompassed within protected areas. However, for various reasons (e.g.,
lack of funding, personnel, or local management commitment), some of
Brazil's protected areas exist without the current capacity to achieve
their stated natural resource objectives (ADEJA 2007, pp. 1-2; Bruner
et al. 2001, p. 125; Costa 2007, p. 7; IUCN 1999, pp. 23-24;
Neotropical News 1996, pp. 9-10; Neotropical News 1999, p. 9).
Therefore, even with the expansion or further designation of protected
areas, it is likely that not all of the identified resource concerns
for
[[Page 40655]]
the black-hooded antwren (e.g., residential and agricultural
encroachment, resource extraction, unregulated tourism, grazing) would
be sufficiently addressed at these sites.
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil, which helped
facilitate the large-scale habitat conversions that have occurred
throughout the Atlantic Forest biome (Brannstrom 2000, p. 326; Butler
2007, p. 3; Conservation International 2007c, p. 1; Pivello 2007, p. 2;
Ratter et al. 1997, pp. 227-228; Saatchi et al. 2001, p. 874). More
recently, the Brazilian government has given greater recognition to the
environmental consequences of such rapid expansion, and has taken steps
to better manage some of the natural resources potentially impacted
(Butler 2007, p. 7; Costa 2007, p. 7; Neotropical News 1997a, p. 10;
Neotropical News 1997b, p. 11; Neotropical News 1998b, p. 9;
Neotropical News 2003, p. 13; Nunes and Kraas 2000, p. 45). Despite
these efforts, pressures to develop coastal areas containing black-
hooded antwren habitat for tourism (e.g., large hotel complexes,
beachside housing) and plantation agriculture continue to be a threat
to the species (ADEJA 2007, pp. 1-2; BLI 2007d, p. 2; Tobias and
Williams 1996, p. 65).
Summary of Factor D
Brazil's wide variety of laws requiring resource protection that
would ultimately benefit the black-hooded antwren are tested by the
intense development pressure that exists in coastal areas south of Rio
de Janeiro. Despite the existence of these regulatory mechanisms,
habitat loss throughout the Atlantic Forest biome has increased for
more than a decade. The existing regulatory mechanisms have proven
difficult to enforce (BLI 2003a, p. 4; Conservation International
2007c, p. 1; Costa 2007, p. 7; The Nature Conservancy 2007, p. 2;
Neotropical News 1997b, p. 11; Peixoto and Silva 2007, p. 5; Scott and
Brooke 1985, pp. 118, 130). As a result, threats to the black-hooded
antwren's remaining habitat are ongoing (see Factor A) due to the
challenges that Brazil faces to balance its competing development and
environmental priorities. Therefore, when combined with Factors A and
E, we find that the existing regulatory mechanisms are inadequate to
ameliorate the current threats to the black-hooded antwren throughout
its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the black-hooded
antwren. In basic terms, demographic stochasticity is defined by chance
changes in the population growth rate for the species (Gilpin and
Soul[eacute] 1986, p. 27). Population growth rates are influenced by
individual birth and death rates (Gilpin and Soul[eacute] 1986, p. 27),
immigration and emigration rates, as well as changes in population sex
ratios. Natural variation in survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27). Genetic stochasticity is caused by changes in gene
frequencies due to genetic drift, and diminished genetic diversity,
and/or effects due to inbreeding (i.e., inbreeding depression) (Lande
1995, p. 786). Inbreeding can have individual or population-level
consequences either by increasing the phenotypic expression (the
outward appearance, or observable structure, function, or behavior of a
living organism) of recessive, deleterious alleles or by reducing the
overall fitness of individuals in the population (Charlesworth and
Charlesworth 1987, p. 231; Shaffer 1981, p. 131). Environmental
stochasticity is defined as the susceptibility of small, isolated
populations of wildlife species to natural levels of environmental
variability and related ``catastrophic'' events (e.g., severe storms,
prolonged drought, extreme cold spells, wildfire) (Dunham et al. 1999,
p. 9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). Each risk
will be analyzed specifically for the black-hooded antwren.
Small, isolated populations of wildlife species are susceptible to
demographic and genetic problems (Shaffer 1981, pp. 130-134). These
threat factors, which may act in concert, include: natural variation in
survival and reproductive success of individuals, chance disequilibrium
of sex ratios, changes in gene frequencies due to genetic drift,
diminished genetic diversity and associated effects due to inbreeding
(i.e., inbreeding depression), dispersal of just a few individuals, a
few clutch failures, a skewed sex ratio in recruited offspring over
just one or a few years, and chance mortality of just a few
reproductive-age individuals.
There is very little information available regarding the historic
distribution and abundance of the black-hooded antwren. However, the
species' historic population was likely larger and more widely
distributed than today, and it must have maintained a minimum level of
genetic interchange among its local subpopulations in order for them to
have persisted (Middleton and Nisbet 1997, p. 107; Vil[agrave] et al.
2002, p. 91; Wang 2004, p. 332). The available information indicates
that suitable habitats currently occupied by the black-hooded antwren
are highly fragmented and that the species' extant population is small
and declining (BLI 2007d, pp. 1-3). Without efforts to maintain buffer
areas and reconnect some of the remaining tracts of suitable habitat
near the species' currently occupied sites, it is doubtful that the
individual tracts are currently large enough to support viable
populations of many birds endemic to the Atlantic Forest, like the
black-hooded antwren, and the eventual loss of any small, isolated
populations appears to be inevitable (Goerck 1997, p. 117; Harris and
Pimm 2004, pp. 1609-1610; IUCN 1999, pp. 23-24; Machado and Da Fonseca
2000, pp. 914, 921-922; Saatchi et al. 2001, p. 873; Scott and Brooke
1985, p. 118).
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the black-hooded antwren (see Factors A and D).
We expect that any additional loss or degradation of habitats that are
used by the black-hooded antwren will have disproportionately greater
impacts on the species due to the population's fragmented state. This
is because with each contraction of an existing subpopulation, the
likelihood of interchange with other subpopulations within patches
decreases, while the likelihood of its complete reproductive isolation
increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986,
[[Page 40656]]
p. 31). Furthermore, as a species' status continues to decline, often
as a result of deterministic forces such as habitat loss or
overutilization, it will become increasingly vulnerable to a broad
array of other forces. If this trend continues, its ultimate extinction
due to one or more stochastic events becomes more likely.
We expect that the black-hooded antwren's increased vulnerability
to demographic stochasticity and inbreeding will be operative even in
the absence of any human-induced threats or stochastic environmental
events, which only act to further exacerbate the species' vulnerability
to local extirpations and eventual extinction. Demographic and genetic
stochastic forces typically operate synergistically. Initial effects of
one threat factor can later exacerbate the effects of other threat
factors, as well as itself (Gilpin and Soul[eacute] 1986, pp. 25-26).
For example, any further fragmentation of the populations will, by
definition, result in the further removal or dispersal of individuals,
which will exacerbate the other threats. Conversely, lack of a
sufficient number of individuals in a local area or a decline in their
individual or collective fitness may cause a decline in the population
size, despite the presence of suitable habitat patches.
Small, isolated populations of wildlife species, such as the black-
hooded antwren, are also susceptible to natural levels of environmental
variability and related ``catastrophic'' events (e.g., severe storms,
prolonged drought, extreme cold spells, wildfire), which we will refer
to as environmental stochasticity (Dunham et al. 1999, p. 9; Mangel and
Tier 1994, p. 612; Young 1994, pp. 410-412). A single stochastic
environmental event can severely reduce existing wildlife populations
and, if the affected population is already small or severely
fragmented, it is likely that demographic stochasticity or inbreeding
will become operative, which would place the population in jeopardy
(Gilpin and Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-789).
Summary of Factor E
The small and declining numbers that make up the black-hooded
antwren's population makes it susceptible to natural environmental
variability or chance events. In addition to its declining numbers, the
high level of population fragmentation makes the species susceptible to
genetic and demographic stochasticity. Therefore, we find that
demographic, genetic, and environmental stochastic events are a threat
to the continued existence of the black-hooded antwren throughout its
range.
Status Determination for the Black-hooded Antwren
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the black-hooded antwren. The species is
currently at risk throughout all of its range due to ongoing threats of
habitat destruction and modification (Factor A), and demographic,
genetic, and environmental stochastic events associated with the
species' high level of population fragmentation (Factor E).
Furthermore, we have determined that the existing regulatory mechanisms
(Factor D) are not adequate to ameliorate the current threats to the
species.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Based on the threats to the black-hooded antwren throughout
its entire range, as described above, we determine that the black-
hooded antwren is in danger of extinction throughout all of its range.
Therefore, on the basis of the best available scientific and commercial
information, we are proposing to list the black-hooded antwren as an
endangered species throughout all of its range.
II. Brazilian Merganser (Mergus Octosetaceus)
Species Description
The 49-56 cm (19-22 in) (BLI 2007a, p. 1) Brazilian merganser is
described as resembling a cormorant (Sisk 1993, p. 163). The bird has a
white wing speculum and red feet. The breast is pale grey with dark
markings, and there is dark grey coloring in the upper breast (BLI
2007a, p. 1). The species has a distinctive green crest that extends
over the nape of the neck (more developed in the male) (Sisk 1993, p.
163).
Taxonomy
The Brazilian merganser was first described by Vieillot in 1817
(Partridge 1956, p. 473). The species belongs in the family Anatidae
(BLI 2007a, p. 1).
Habitat and Life History
The Brazilian merganser is highly adapted to shallow, rapid, clear-
water streams and rivers, typically bordered by dense, tropical forest
(Bruno et al. 2006, p. 26; Collar et al. 1992, pp. 80-86; Ducks
Unlimited 2007, p. 1; Hughes et al. 2006, p. 23; Partridge 1956, pp.
478-480; Sibley and Monroe 1990, p. 41). Where suitable riverine
conditions exist, the Brazilian merganser also occurs in the Cerrado
biome, which is characterized by open tropical savannah and
comparatively sparse ``gallery'' forest at the river margins,
indicating that the species is not strictly tied to tropical forest
habitats (Bianchi et al. 2005, p. 73; Braz et al. 2003, p. 70).
Brazilian mergansers are strong swimmers and divers. They typically
feed in river rapids or in pools adjacent to waterfalls, whereas they
rest and perch in more slack water areas or at the river edges (Braz et
al. 2003, p. 70; Hughes et al. 2006, p. 21; Partridge 1956, pp. 481-
482). Brazilian mergansers feed primarily on a variety of fish species,
with sizes up to approximately 19 cm (7.5 in), and occasionally on
insects, snails, and other aquatic macro-invertebrates (Hughes et al.
2006, p. 32; Partridge 1956, p. 483).
Brazilian mergansers are believed to be monogamous and sedentary.
Breeding pairs appear to maintain their territories along a stretch of
river (up to ca. 12 km (7.5 mi)) throughout the year (Braz et al. 2003,
p. 70; Ducks Unlimited 2007, p. 1; Hughes et al. 2006, pp. 23, 33;
Partridge 1956, p. 477). The breeding season begins in June and young
hatch around August (Partridge 1956, p. 487). Females establish their
nests relatively high up (25 m (82 ft)) in the cavities of tall trees
that overlook the river and incubate their eggs alone, although males
are attentive and remain nearby feeding and perching at the river
shoreline (Bruno et al. 2006, p. 29; Lamas and Santos 2004, p. 38;
Partridge 1956, pp. 484-485). Females may also locate their nests lower
down (10 m (33 ft)) in the cavities of cliffs or rocky outcrops near
preferred riverine habitat in areas where suitable nesting trees are
absent (Lamas and Santos 2004, pp. 38-39).
Range and Distribution
The Brazilian merganser occurs in a few fragmented locations in
south-central Brazil, including the upper-tributaries of rivers within
the Atlantic Forest biome and to the east in the Cerrado (savanna)
biome (BLI 2007a, p. 1). The species is a diving duck that occurred
historically in riverine habitats throughout southeastern Brazil,
northeastern Argentina, and eastern Paraguay (Hughes et al. 2006, p.
24). Currently, the species is found in extremely low numbers at six
highly disjunct localities, of which five are in southeastern Brazil
and one is in northeastern Argentina and, possibly,
[[Page 40657]]
extreme eastern Paraguay (BLI 2007a, pp. 1-5; Hughes et al. 2006, pp.
28-31). The vast majority of the species' extant population and
remaining suitable habitats occur in Brazil, including its largest
subpopulation that is estimated to contain fewer than 50 individuals
(BLI 2007a, p. 5).
The Brazilian merganser is thought to have been extirpated from
Mato Grosso do Sul, S[atilde]o Paolo, Rio de Janeiro, and Santa
Catarina (BLI 2007a, pp. 1-2). There is only a single recent record of
the Brazilian merganser (ca. 2002) in the province of Misiones,
Argentina, while the last confirmed sighting of the species in Paraguay
is from 1984 (BLI 2007a, p. 2; Hughes et al. 2006, p. 31). For purposes
of this proposed rule, our analysis will focus on the most current
estimates of the species, which are based in Brazil.
The species likely still occurs in the Brazilian states of
Tocantins, Bahia, Goi[aacute]s, Minas Gerais, and Paran[aacute] (Hughes
et al. 2006, pp. 51-52). Along with other recent sightings of the
species in previously undocumented areas of Brazil (Bianchi et al.
2005, p. 72; Pineschi 1999, p. 1), this information indicates that the
Brazilian merganser may be more abundant and widespread than previously
considered.
Population Estimates
The extant population is estimated to be between 50 and 249
individuals and is presumed to be declining, as evidenced by the
species' recent history of extirpation from major portions of its
historic range (BLI 2007a, p. 1).
Conservation Status
IUCN considers the Brazilian merganser to be ``Critically
Endangered'' because ``although recent records from Brazil, and
particularly a recent northerly range extension, indicate that this
species' status is better than previously thought, the remaining
population is still extremely small and severely fragmented, and the
perturbation and pollution of rivers continues to cause declines'' (BLI
2007a, p. 1). In addition, the species occurs in three parks in Brazil
and in the Urugua[iacute] Provincial Park in Argentina (BLI 2007a, p.
1).
Summary of Factors Affecting the Brazilian Merganser
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Based on a number of recent estimates, 92 to 95 percent of the area
historically covered by tropical forests within the Atlantic Forest
biome has been converted or severely degraded as a result of various
human activities (Conservation International 2007a, p. 1; H[ouml]fling
2007, p. 1; Morellato and Haddad 2000, p. 786; Myers et al. 2000, pp.
853-854; The Nature Conservancy 2007, p. 1; Saatchi et al. 2001, p.
868; World Wildlife Fund 2007, pp. 2-41). The Cerrado biome has also
been heavily impacted by human activities, and current estimates
indicate that between 67 and 80 percent of the tropical savannah
habitat historically comprising this biome has been converted or
severely degraded (Butler 2007, p. 1; Conservation International 2007b,
p. 1; Mantovani and Pereira 1998, p. 1455; Myers et al. 2000, p. 854;
World Wildlife Fund 2007, p. 50). In addition to the overall loss and
degradation of native habitat within these biomes, the remaining tracts
of habitat are severely fragmented. The current rate of habitat loss in
the Atlantic Forest and Cerrado biomes is unknown.
The region has the two largest cities in Brazil, S[atilde]o Paulo
and Rio de Janeiro, and is home to approximately 70 percent of Brazil's
169 million people (CEPF 2002; IBGE 2007). The major human activities
that have resulted in the loss, degradation, and fragmentation of
native habitats within these biomes include extensive establishment of
agricultural fields (e.g., soy beans, sugarcane, and corn), plantations
(e.g., eucalyptus, pine, coffee, cocoa, rubber, and bananas), livestock
pastures, centers of human habitation, and industrial developments
(e.g., diamond mining, hydropower reservoirs, and charcoal production).
Forestry practices (e.g., commercial logging), subsistence activities
(e.g., collection of fuelwood), and changes in fire frequencies also
contribute to the degradation of native habitat (BLI 2003a, p. 4; BLI
2003b, pp. 1-2; Butler 2007, p. 1; Hughes et al. 2006, pp. 37-48;
J[uacute]nior et al. 1995, p. 147; Nunes and Kraas 2000, p. 44; Pivello
2007, pp. 1-2; Ratter et al. 1997, pp. 227-228; Saatchi et al. 2001,
pp. 868-869; World Food Prize 2007, pp. 1-5; World Wildlife Fund 2007,
pp. 3-51).
The Brazilian merganser is extremely susceptible to habitat loss
and degradation, habitat fragmentation, and hydrological changes from
human activity (Collar et al. 1992, pp. 83-84; Hughes et al. 2006, pp.
36-41; Silveira 1998, p. 58). The loss of appropriate aquatic and
terrestrial habitats throughout the historic range of the Brazilian
merganser due to the above human activities is believed to have
drastically reduced the species' abundance and extent of occupied
range, and these activities currently represent a significant risk to
the species' continued existence because populations are being limited
to highly fragmented patches of habitat (Benstead 1994, p. 8; Benstead
et al. 1994, p. 36; BLI 2007a, pp. 1-6; Collar and Andrew 1988, p. 21;
Collar et al. 1992, pp. 83-84; Collar et al. 1994, p. 51; Hughes et al.
2006, pp. 37-48; Silveira 1998, pp. 57-58).
The species is highly adapted to shallow, rapid-flowing riverine
conditions and, therefore, can not occupy the lacustrine conditions of
reservoirs that result from dam building activities within their
occupied range (Hughes et al. 2006, pp. 23, 41). The loss of the
species' terrestrial habitat has occurred due to the removal of forest
cover and suitable nesting trees adjacent to occupied river corridors.
A variety of secondary impacts that degrade suitable habitats have
also resulted from the above activities and represent significant risks
to the Brazilian merganser. These secondary impacts include increased
runoff and severe siltation from agricultural fields, livestock
pastures, deforestation, diamond mining, and population centers;
changes in hydrologic conditions and local water tables as a result of
dam operations (e.g., flood control, power generation) and excessive
pumping for irrigation or domestic and industrial water use; and
increases in water pollutants due to agricultural, industrial, and
domestic waste products (Benstead 1994, p. 8; Bianchi et al. 2005, p.
73; BLI 2007a, pp. 1-6; Braz et al. 2003, p. 70; Collar et al. 1994, p.
51; del Hoyo et al. 1992, p. 625; Ducks Unlimited 2007, p. 1; Hughes et
al. 2006, pp. 40-48; Lamas and Santos 2004, p. 40; Pineschi 1999, p.
1). These secondary impacts negatively affect the Brazilian merganser
by reducing water clarity, altering water depths and flow patterns,
removing or limiting populations of preferred prey species; introducing
toxic compounds; and creating barriers to movements and producing
hazardous conditions along river corridors that limit interchange
between the species' remaining subpopulations (see Factor E). These
secondary impacts also increase the risk of introducing disease vectors
and expanding populations of potential predator and competitor species
into areas occupied by the Brazilian merganser (see Factor C).
Summary of Factor A
The above mentioned human activities and their secondary impacts
have significantly reduced the amount of suitable habitat for the
Brazilian merganser (Benstead 1994, p. 8;
[[Page 40658]]
Benstead et al. 1994, p. 36; BLI 2007a, pp. 1-6; Collar and Andrew
1988, p. 21; Collar et al. 1992, pp. 83-84; Collar et al. 1994, p. 51;
Hughes et al. 2006, pp. 37-48; Silveira 1998, pp. 57-58), and the
remaining areas of occupied habitat are highly fragmented (see Factor
E). In addition, these activities are ongoing and continue to adversely
impact all of the remaining suitable habitat within the Atlantic Forest
and Cerrado biomes that may still harbor the Brazilian merganser (BLI
2003a, p. 4; BLI 2003b, pp. 1-2; BLI 2007a, pp. 1-7; Brannstrom 2000,
p. 326; Ducks Unlimited 2007, p. 1; Harris and Pimm 2004, p. 1610;
Hughes et al. 2006, pp. 37-48; Morellato and Haddad 2000, p. 786;
Saatchi et al. 2001, pp. 868-873; Tabanez and Viana 2000, pp. 929-932).
Even with the recent passage of national forest policy and in light of
many other legal protections in Brazil (see Factor D), the rate of
habitat loss throughout southeastern Brazil has increased since the
mid-1990s (CEPF 2001, p. 10; Hodge et al. 1997, p. 1; Rocha et al.
2005, p. 270). Furthermore, because the Brazilian merganser's extant
population is already extremely small, highly fragmented, and believed
to be declining (BLI 2007a, pp. 1-4), any further loss or degradation
of its remaining suitable habitat will severely impact the species (see
Factor E). Therefore, we find that destruction and modification of
habitat are threats to the continued existence of the Brazilian
merganser throughout its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Historically, there was likely little range-wide hunting pressure
on the Brazilian merganser, presumably due to the species' secretive
nature, naturally low densities in relatively inaccessible areas, and
poor palatability (Partridge 1956, p. 478). However, low levels of
subsistence hunting of some local populations still occurs, most
notably in Argentina (Benstead 1994, p. 8; del Hoyo et al. 1992, p.
625; Hughes et al. 2006, p. 48).
Since the first formal description of the species in the early
1800s, the Brazilian merganser has also been collected for scientific
study and museum exhibition (BLI 2007a, p. 2; Hughes et al. 2006, p.
46). Past hunting and specimen collection may have contributed to the
species' decline in some areas (Hughes et al. 2006, p. 46). These
activities continue today, although presumably at low levels (Benstead
1994, p. 8; Hughes et al. 2006, p. 48; Lamas and Santos 2004, p. 39).
Summary of Factor B
Species collection for scientific study and museum exhibition, and
hunting, are believed to affect the population of the Brazilian
merganser. Considering the extremely small size and level of
fragmentation of the extant Brazilian merganser population, the removal
or dispersal of any individuals from a local area, or even a slight
decline in the population's fitness, represent significant risks to the
species' overall viability (see Factor E). However, we do not have
information on the extent of species collection or hunting to determine
whether these activities are a threat to the continued existence of the
species. As a result, we are not considering overutilization to be a
contributing factor to the continued existence of the Brazilian
merganser.
C. Disease or Predation
Extensive human activity in previously undisturbed or isolated
areas can lead to the introduction and spread of exotic diseases, some
of which (e.g., West Nile virus) can negatively impact endemic bird
populations (Neotropical News 2003, p. 1; Naugle et al. 2004, p. 704).
In addition, there are a number of suspected predators of the Brazilian
merganser (Hughes et al. 2006, p. 44; Lamas and Santos 2004, p. 39;
Partridge 1956, p. 486). Partridge (1956, p. 480) hypothesized that the
species' distribution may be naturally limited to upper river
tributaries above waterfalls due to predation of their young by large
predatory fish, such as the dourado (Salminus brasiliensis, syn.
maxillosus). Finally, extensive human activity in previously
undisturbed or isolated areas can result in altered predator or
competitor (e.g., cormorant (Phalacrocorax sp.)) populations and the
introduction of various exotic predator species, such as feral dogs
(Canis familiaris) and game fish like largemouth bass (Micropterus
salmoides) (Hughes et al. 2006, pp. 44-45).
The available information indicates that there is a greatly
expanded human population within the Brazilian merganser's historic
range and that the species' extant population is extremely small,
highly fragmented, and likely declining. Although large, stable
populations of wildlife species have adapted to natural levels of
disease and predation within their historic ranges, any additive
mortality to the Brazilian merganser population or a decrease in its
fitness due to an increase in the incidence of disease or predation
could adversely impact the species' overall viability (see Factor E).
However, while these potential influences remain a concern for future
management of the species, we are not aware of any information
currently available that specifically indicates the occurrence of
disease in the Brazilian merganser, or that documents actual predation
levels incurred by any of the species' local subpopulations. As a
result, we are not considering disease or predation to be a
contributing factor to the continued existence of the Brazilian
merganser.
D. The Inadequacy of Existing Regulatory Mechanisms
The Brazilian merganser is legally protected by national
legislation promulgated by the governments in all three countries where
it historically occurred (Hughes et al. 2006, pp. 50-57). In Brazil,
where the vast majority of the species' extant population and remaining
suitable habitats occur (BLI 2007a, pp. 1-2; Hughes et al. 2006, pp.
28-31), the Brazilian merganser is formally recognized as
``endangered'' (Order No. 1.522), and there are regulatory mechanisms
that require direct protection of the species (ECOLEX 2007, pp. 1-2).
These include measures that prohibit, or regulate through Federal
agency oversight, the following activities with regard to endangered
species: export and international trade (e.g., Decree No. 76.623, Order
No. 419-P), hunting (e.g., Act No. 5.197), collection and research
(Order No. 332), captive propagation (Order No. 5), and general harm
(e.g., Decree No. 3.179).
There are also a wide range of regulatory mechanisms in Brazil that
indirectly protect the Brazilian merganser through measures that
protect its remaining suitable habitats (ECOLEX 2007, pp. 2-5). For
example, there are measures that: (1) Prohibit exploitation of the
remaining primary forests within the Atlantic Forest biome and gallery
forests adjacent to river corridors (e.g., Decree No. 750, Resolution
No. 10, Act No. 7.754); (2) govern various practices associated with
the management of primary and secondary forests, such as logging,
charcoal production, reforestation, recreation, and water resources
(e.g., Resolution No. 9, Act No. 4.771, Decree No. 1.282, Decree No.
3.420, Order No. 74-N, Act No. 7.803); (3) establish provisions for
controlling forest fires (e.g., Decree No. 97.635, Order No. 231-P,
Order No. 292-P, Decree No. 2.661); and (4) regulate industrial
developments, such as hydroelectric plants and biodiesel production
(e.g., Normative Instruction No. 65, Law No. 11.116). Measures also
exist (e.g., Law No. 11.516, Act No. 7.735, Decree No.
[[Page 40659]]
78, Order No. 1, Act No. 6.938) that direct Federal and State agencies
to promote the protection of lands and natural resources under their
jurisdictions (ECOLEX 2007, pp. 5-6).
Regulatory mechanisms in Brazil govern the formal establishment and
management of protected areas to promote conservation of the country's
natural resources (ECOLEX 2007, pp. 6-7). These mechanisms generally
aim to protect endangered wildlife and plant species, genetic
resources, overall biodiversity, and native ecosystems on Federal,
State, and privately owned lands (e.g., Law No. 9.985, Law No. 11.132,
Resolution No. 4, Decree No. 1.922). Brazil's formally established
protection areas are categorized based on their overall management
objectives (e.g., National Parks versus Biological Reserves) and, based
on those categories, allow varying uses and provide varying levels of
protection for specific resources (Costa 2007, pp. 5-19). Four of
Brazil's protected areas represent the major sites where the Brazilian
merganser still occurs (Hughes et al. 2006, pp. 53-54). These areas are
considered critical for protecting some of the species' key remaining
subpopulations (Bianchi et al. 2005, pp. 72-74; BLI 2007a, pp. 1-2;
Braz et al. 2003, pp. 68-71; Bruno et al. 2006, p. 30; Collar et al.
1992, pp. 84-85; del Hoyo et al. 1992, p. 625; Lamas and Santos 2004,
pp. 39-40; Silveira 1998, pp. 57-58). Notable among these areas are the
Serra da Canastra National Park in Minas Gerais, which currently
encompasses a portion of the species' largest known subpopulation
(Bruno et al. 2006, p. 25), and the Chapada dos Veadeiros National Park
in Goi[aacute]s (Bianchi et al. 2005, pp. 72-73). The Service recently
provided funding for a project to develop and strengthen conservation
partnerships with local agricultural producers in the Serra da Canastra
region, which could benefit the Brazilian merganser (USFWS 2006, p. 3).
Although four categories of protected areas under Brazilian law
include important sites where the species occurs, unregulated tourism,
resource extraction, and livestock grazing continue in these areas and
pose threats to the Brazilian merganser. In addition, not all of the
remaining Brazilian mergansers occur in these protected areas. Some key
areas where the species occurs are currently not formally protected and
are subject to ongoing threats, such as proposed hydropower projects,
logging, and continuing development.
Due to various reasons (e.g., lack of funding, personnel, or local
management commitment), some of Brazil's protected areas exist without
current capacity to achieve their stated natural resource objectives
(IUCN 1999, pp. 23-24; Neotropical News 1996, pp. 9-10; Neotropical
News 1999, p. 9; Costa 2007, p. 7). For example, the Worldwide Fund for
Nature found in its study that 47 of 86 protected areas were found to
be below the minimum level of implementation of Federal requirements,
with only 7 considered to be fully implemented (Neotropical News 1999,
p. 9).
Despite the existence of these regulatory mechanisms, habitat loss
throughout the Atlantic Forest biome has increased for more than a
decade (BLI 2003a, p. 4; BLI 2003b, pp. 1-2; Braz et al. 2003, p. 70;
Collar et al. 1992, p. 84; Hughes et al. 2006, p. 61; Lamas and Santos
2004, p. 40; The Nature Conservancy 2007, p. 2; Neotropical News 1997b,
p. 11; Scott and Brooke 1985, p. 118). Illegal or unauthorized
activities that continue to impact the Brazilian merganser include
logging of gallery forests within riverine buffer areas; encroachment
of logging, livestock grazing, and subsistence activities within
protected primary and secondary forests; hunting; intentional burning;
and collection of eggs and adult birds from the wild (BLI 2003b, p. 1;
Hughes et al. 2006, p. 61; The Nature Conservancy 2007, p. 2).
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil, which helped
facilitate the large-scale conversions that have occurred in the
Atlantic Forest and Cerrado biomes (Brannstrom 2000, p. 326; Butler
2007, p. 3; Conservation International 2007c, p. 1; Pivello 2007, p. 2;
Ratter et al. 1997, pp. 227-228; Saatchi et al. 2001, p. 874). Some of
these projects, if developed, would impact important sites for the
Brazilian merganser and would affect habitat within and adjacent to
established protection areas. These projects include further
development of dams for hydroelectric power, irrigation, or municipal
water supplies; expansion of agricultural practices, primarily for
soybean production; and increasing tourism enterprises (Braz et al.
2003, p. 70; Hughes et al. 2006, pp. 51-56).
Summary of Factor D
Brazil's wide variety of laws requiring resource protection would
ultimately benefit the Brazilian merganser, but they are tested by the
intense development pressure that exists within the species' range.
Government-sponsored measures in Brazil continue to facilitate
development projects, however regulatory mechanisms also exist that
require protection of the Brazilian merganser and its habitat. Despite
the existence of these regulatory mechanisms, there are a few
challenges, including the fact that protected areas do not address all
the threats to the Brazilian merganser, protected areas do not
encompass all occupied habitat of the species, there are government
sponsored programs that encourage development within the range of the
species, and protections that would benefit the species are not
adequately enforced. As a result, threats to the species' remaining
habitat are ongoing (see Factor A). Therefore, when combined with
Factors A and E, we find that the existing regulatory mechanisms are
inadequate to ameliorate the current threats to the Brazilian merganser
throughout its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the Brazilian
merganser. In basic terms, demographic stochasticity is defined by
chance changes in the population growth rate for the species (Gilpin
and Soul[eacute] 1986, p. 27). Population growth rates are influenced
by individual birth and death rates (Gilpin and Soul[eacute] 1986, p.
27), immigration and emigration rates, as well as changes in population
sex ratios. Natural variation in survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27). Genetic stochasticity is caused by changes in gene
frequencies due to genetic drift, and diminished genetic diversity,
and/or effects due to inbreeding (i.e., inbreeding depression) (Lande
1995, p. 786). Inbreeding can have individual or population-level
consequences either by increasing the phenotypic expression (the
outward appearance or observable structure, function or behavior of a
living organism) of recessive, deleterious alleles or by reducing the
overall fitness of individuals in the population (Charlesworth and
Charlesworth 1987, p. 231; Shaffer 1981, p. 131). Environmental
stochasticity is defined as the susceptibility of small, isolated
populations of wildlife species to natural levels of environmental
variability and related ``catastrophic'' events (e.g., severe storms,
prolonged drought, extreme cold spells, wildfire)
[[Page 40660]]
(Young 1994, pp. 410-412; Mangel and Tier 1994, p. 612; Dunham et al.
1999, p. 9). Each risk will be analyzed specifically for the Brazilian
merganser.
Small, isolated populations of wildlife species are susceptible to
demographic and genetic problems (Shaffer 1981, pp. 130-134). These
threat factors, which may act in concert, include: natural variation in
survival and reproductive success of individuals, chance disequilibrium
of sex ratios, changes in gene frequencies due to genetic drift,
diminished genetic diversity and associated effects due to inbreeding
(i.e., inbreeding depression), dispersal of just a few individuals, a
few clutch failures, a skewed sex ratio in recruited offspring over
just one or a few years, and chance mortality of just a few
reproductive-age individuals.
The Brazilian merganser has likely always been a rare species, with
small local populations occupying the naturally restricted sites of
suitable habitat within the upper-tributaries of river systems in east-
central South America (Lamas and Santos 2004, pp. 38-39; Partridge
1956, pp. 477-478). In addition, while there is no direct evidence
currently available, Yamashita (in Hughes et al. 2006, p. 43)
speculated that the species has likely always had a naturally low level
of genetic variability as a result of its life history strategy.
It was further speculated that inbreeding in the Brazilian
merganser has not significantly affected the species, presumably due to
the species' natural tolerance for low genetic variability (Hughes et
al. 2006, p. 43). However, relatively low levels of genetic interchange
between local subpopulations can act to maintain the genetic viability
of a metapopulation (Vil[agrave] et al. 2002, p. 91; Wang 2004, p. 332)
and, historically, it seems likely that the Brazilian merganser
maintained such minimum levels of interchange across its occupied range
in order for its subpopulations to have persisted (Middleton and Nisbet
1997, p. 107).
In the absence of more species-specific life history data, a
general approximation of a minimum viable population size is referred
to as the 50/500 rule (Franklin 1980, p. 147). This rule states that an
effective population (Ne) of 50 individuals is the minimum
size required to avoid imminent risks from inbreeding. Ne
represents the number of animals in a population that actually
contribute to reproduction, and is often much smaller than the total
number of individuals in the population (N). For example, not all
individuals reproduce. Furthermore, the rule states that the long-term
fitness of a population requires an Ne of at least 500
individuals so that it will not lose its genetic diversity over time
and will maintain an enhanced capacity to adapt to changing conditions.
The available information indicates that the extant Brazilian
merganser population is extremely small (i.e., between 50 and 249
individuals) and highly fragmented. The lower limit of the population
(50 individuals) teeters on the edge of the minimum number of
individuals required to avoid imminent risks from inbreeding
(Ne = 50). The current maximum estimate of 249 individuals
for the entire population (BLI 2007a, p. 1) is only half of the upper
threshold (Ne = 500) required to maintain genetic diversity
over time and to maintain an enhanced capacity to adapt to changing
conditions. Furthermore, these small, fragmented populations are likely
reproductively isolated due to extensive habitat modifications that
have taken place throughout the species' historic distribution (see
Factor A). As such, we currently consider the Brazilian merganser to be
at risk due to its lack of near- and long-term genetic viability.
Available information indicates that the Brazilian merganser is
still subject to low levels of hunting, specimen collection, and other
human disturbances (see Factors E and D). For species with large and/or
well-interconnected subpopulations, low levels of the above influences
would normally be of little consequence. However, considering the
extremely small size and likely isolation of the species' extant
subpopulations, and the likelihood of continued fragmentation of its
occupied habitats, the removal or dispersal of any individuals from a
local area, or even a slight decline in the individual or population
fitness of these birds, represent significant risks to the continued
existence of the Brazilian merganser.
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the Brazilian merganser (see Factors A and D). We
expect that any additional loss or degradation of habitats that are
used by the Brazilian merganser will have disproportionately greater
impacts on the species due to the population's fragmented state. This
is because with each contraction of an existing subpopulation, the
likelihood of interchange with other subpopulations within patches
decreases, while the likelihood of its complete reproductive isolation
increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986, p. 31).
Without efforts to maintain buffer areas and reconnect some of the
remaining tracts of suitable habitat near the species' currently
occupied sites, it is doubtful that the individual tracts are currently
large enough to support viable populations, and the eventual loss of
any small, isolated populations appears to be inevitable (Goerck 1997,
p. 117; Harris and Pimm 2004, pp. 1609-1610; IUCN 1999, pp. 23-24;
Machado and Da Fonseca 2000, pp. 914, 921-922; Saatchi et al. 2001, p.
873; Scott and Brooke 1985, p. 118). Furthermore, as a species' status
continues to decline, often as a result of deterministic forces such as
habitat loss or overutilization, it will become increasingly vulnerable
to a broad array of other forces. If this trend continues, its ultimate
extinction due to one or more stochastic events becomes more likely.
We expect that the Brazilian merganser's increased vulnerability to
demographic stochasticity and inbreeding will be operative even in the
absence of any human-induced threats or stochastic environmental
events, which only act to further exacerbate the species' vulnerability
to local extirpations and eventual extinction. Demographic and genetic
stochastic forces typically operate synergistically. Initial effects of
one threat factor can later exacerbate the effects of other threat
factors, as well as itself (Gilpin and Soul[eacute] 1986, pp. 25-26).
For example, any further fragmentation of populations will, by
definition, result in the further removal or dispersal of individuals,
which will exacerbate the other threats. Conversely, lack of a
sufficient number of individuals in a local area or a decline in their
individual or collective fitness may cause a decline in the population
size, despite the presence of suitable habitat patches.
Small, isolated populations of wildlife species, such as the
Brazilian merganser, are also susceptible to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged
[[Page 40661]]
drought, extreme cold spells, wildfire), which we will refer to as
environmental stochasticity (Dunham et al. 1999, p. 9; Mangel and Tier
1994, p. 612; Young 1994, pp. 410-412). A single stochastic
environmental event can severely reduce existing wildlife populations
and, if the affected population is already small or severely
fragmented, it is likely that demographic stochasticity or inbreeding
will become operative, which would place the population in jeopardy
(Gilpin and Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-789).
In addition to these stochastic threats, the Brazilian merganser is
sensitive to human disturbance activities. Each breeding pair of the
Brazilian merganser requires relatively long segments of river (up to
ca. 12 km (7.5 mi)) (Braz et al. 2003, p. 70; Bruno et al. 2006, p. 30;
Silvera 1998, pp. 57-58). Breeding success and recruitment of young in
a local area is believed to be negatively affected by human
disturbance. Sources of human disturbance include various ongoing
activities associated with a vastly expanded human population within
the species' occupied range, including tourism (e.g., birding, river
rafting, trekking, off-road vehicle use) and scientific research
programs (Braz et al. 2003, p. 70; Bruno et al. 2006, p. 30; Silvera
1998, pp. 57-58).
Summary of Factor E
The small and declining numbers that make up the Brazilian
merganser's population makes it susceptible to natural environmental
variability or chance events. In addition to its declining numbers, the
high level of population fragmentation makes the species susceptible to
genetic and demographic stochasticity. Therefore, we find that
demographic, genetic, and environmental stochastic events are a threat
to the continued existence of the Brazilian merganser throughout its
range.
Status Determination for the Brazilian merganser
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the Brazilian merganser. Activities associated
with a vastly expanded human population within the species' occupied
range, including tourism (e.g., birding, river rafting, trekking, off-
road vehicle use), scientific research programs, livestock grazing, and
infrastructure development, all represent multiple sources of
additional disturbance to the Brazilian merganser. The species is
currently at risk throughout all of its range due to ongoing threats of
habitat destruction and modification (Factor A), and its lack of near-
and long-term genetic viability due to threats associated with
demographic, genetic, and environmental stochasticity (Factor E).
Furthermore, we have determined that the existing regulatory mechanisms
(Factor D) are not adequate to ameliorate the current threats to the
species.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Based on the threats to the Brazilian merganser throughout its
entire range, as described above, we determine that the Brazilian
merganser is in danger of extinction throughout all of its range.
Therefore, on the basis of the best available scientific and commercial
information, we are proposing to list the Brazilian merganser as an
endangered species throughout all of its range.
III. Cherry-throated Tanager (Nemosia rourei)
Species Description
The cherry-throated tanager has distinctive black plumage on its
head with a white crown, black coloring on the back and wings, white
feathers on its undersides, and red coloring on its throat and upper
chest (BLI 2007g, p. 1).
Taxonomy
The cherry-throated tanager is a member of the Thraupidae family.
It was first described by Cabanis in 1870 (BLI 2007g, p. 1).
Habitat and Life History
The cherry-throated tanager is endemic to the Atlantic Forest biome
and inhabits the upper canopies of trees within humid, montane, primary
forests (Bauer et al. 2000, pp. 97-104; BLI 2007g, pp. 1-2; Venturini
et al. 2005, pp. 60-64). The cherry-throated tanager is a primary
forest-obligate species that typically forages within the interior
crowns of tall, epiphyte-laden trees and occasionally within lower
levels (ca. 2 m (6.6 ft)) at the forest edge. The species' diet
includes caterpillars, butterflies, ants, and various other arthropods
(Bauer et al. 2000, BLI 2007g, p. 1; p. 104; Venturini et al. 2005, p.
65). Cherry-throated tanagers can be found in mixed-species flocks and
appear to require relatively large territories (ca. 3.99 km2
(1.544 mi2)) (Venturini et al. 2005, p. 66). Within its
current distribution, the species makes sporadic use of coffee (Coffea
spp.), pine (Pinus spp.), and eucalyptus (Eucalyptus spp.) plantations,
presumably as travel corridors between remaining patches of primary
forest (Venturini et al. 2005, p. 66).
Little is known about the breeding behavior of the cherry-throated
tanager. However, a single field observation indicates that perhaps
both sexes help build nests (Venturini et al. 2002, pp. 43-44). An
observed nest was constructed of moss, and possibly thin twigs, and the
material was placed in natural depressions of branches near the trunk
within the mid-canopy (Venturini et al. 2002, pp. 43-44).
Range and Distribution
The cherry-throated tanager is found in primary forest habitats in
Esp[iacute]rito Santo and, possibly, Minas Gerais and Rio de Janeiro,
Brazil (BLI 2007g, p. 1). Since 1998, the cherry-throated tanager has
been documented at two sites of remnant primary forest in south-central
Esp[iacute]rito Santo. One site is located in Fazenda Pindobas IV in
the municipality of Concei[ccedil][atilde]o; the other is found in
Caet[eacute]s, in the Vargem Alta municipality in southern
Esp[iacute]rito Santo (30 km (18.6 mi) southeast of Pindobas)
(Venturini et al. 2005, p. 61).
Population Estimates
The cherry-throated tanager was presumed to be extinct because the
species was only known from a single specimen collected in the 1800s
and a reliable sighting of eight individuals from 1941 (Collar et al.
1992, p. 896; Ridgely and Tudor 1989, p. 34; Scott and Brooke 1985, p.
126). However, the species was rediscovered in 1998 (Bauer et al. 2000,
p. 97; Venturini et al. 2005, p. 60). IUCN estimates the population to
range from 50 to 249 individuals, and it is believed to be declining
(BLI 2007g, p. 1). However, Venturini et al. (2005, p. 66) speculate
that the IUCN population estimate is too high, considering that the
maximum number of individuals recently recorded was 14, including 6
birds in Pindobas and 8 birds in Caet[eacute]s.
Conservation Status
IUCN considers the cherry-throated tanager to be ``Critically
Endangered'' because its extant population is extremely small
(estimated to be between 50 and 249 individuals), highly fragmented,
and presumed to be declining (BLI 2007g, p. 1).
[[Page 40662]]
Summary of Factors Affecting the Cherry-Throated Tanager
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Based on a number of recent estimates, 92 to 95 percent of the area
historically covered by tropical forests within the Atlantic Forest
biome has been converted or severely degraded as a result of human
activities (Butler 2007, p. 2; Conservation International 2007a, p. 1;
H[ouml]fling 2007, p. 1; Morellato and Haddad 2000, p. 786; Myers et
al. 2000, pp. 853-854; The Nature Conservancy 2007, p. 1; Saatchi et
al. 2001, p. 868; World Wildlife Fund 2007, pp. 2-41). In addition to
the overall loss and degradation of native habitat within this biome,
the remaining tracts of habitat are severely fragmented. The current
rate of habitat decline within the Atlantic Forest is unknown.
The region has the two largest cites in Brazil, S[atilde]o Paulo
and Rio de Janeiro, and is home to approximately 70 percent of Brazil's
169 million people (CEPF 2002; IBGE 2007). The major human activities
that have resulted in the loss, degradation, and fragmentation of
native habitats within the Atlantic Forest biome include extensive
establishment of agricultural fields (e.g., soy beans, sugarcane, and
corn), plantations (e.g., eucalyptus, pine, coffee, cocoa, rubber, and
bananas), livestock pastures, centers of human habitation, and
industrial developments (e.g., charcoal production, steel plants, and
hydropower reservoirs). Forestry practices (e.g., commercial logging),
subsistence activities (e.g., fuelwood collection), and changes in fire
frequencies also contribute to the degradation of native habitat (BLI
2003a, p. 4; J[uacute]nior et al. 1995, p. 147; The Nature Conservancy
2007, p. 2; Nunes and Kraas 2000, p. 44; Peixoto and Silva 2007, p. 5;
Saatchi et al. 2001, pp. 868-869; Scott and Brooke 1985, p. 118; World
Wildlife Fund 2007, pp. 3-51).
Most of the tropical forest habitats believed to have been used
historically by the cherry-throated tanager have been converted or are
severely degraded due to the above human activities (Bauer et al. 2000,
pp. 98-105; BLI 2007, p. 2; Ridgely and Tudor 1989, p. 34; Venturini et
al. 2005, p. 68). Degraded and fragmented forests experience a decrease
in gene flow, which may cause inbreeding and decreased fitness of
forest species (Tabanez and Viana 2000, pp. 929-932). In addition,
increased liana density has been observed in degraded and fragmented
Atlantic forests of Brazil. Liana infestation of these forest fragments
cause tree falls and encourage gap-opportunistic species to take over
(Tabanez and Viana 2000, pp. 929-932), thus altering the old forest
structure and the cherry-throated tanager's habitat.
Secondary impacts that are associated with forest fragmentation and
degradation include the potential introduction of disease vectors or
exotic predators within the species' historic range (see Factor C). As
a result of these secondary impacts, there is often a time lag between
the initial conversion or degradation of suitable habitats and the
extinction of endemic bird populations (Brooks et al. 1999a, p. 1;
Brooks et al. 1999b, p. 1140). Therefore, even without further habitat
loss or degradation, the cherry-throated tanager remains at risk from
past impacts to its primary forest habitats.
Summary of Factor A
The above human activities and their secondary impacts continue to
threaten the last known tracts of habitat within the Atlantic Forest
biome that may still harbor the cherry-throated tanager (BLI 2003a, p.
4; BLI 2007g, p. 5; Conservation International 2007a, p. 1;
H[ouml]fling 2007, p. 1; The Nature Conservancy 2007, p. 1; Venturini
et al. 2005, p. 68; World Wildlife Fund 2007, pp. 3-51). Because the
species' extant population is extremely small, highly fragmented, and
believed to be declining (BLI 2007g, p. 1), any further loss or
degradation of its remaining suitable habitat will adversely impact the
cherry-throated tanager. Therefore, we find that past and ongoing
destruction and modification of the cherry-throated tanager's habitat
are threats to the continued existence of the species throughout its
range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The extant population of the cherry-throated tanager is considered
to be extremely small, highly fragmented, and declining (BLI 2007g, p.
1; Venturini et al. 2005, p. 66). Because of the cherry-throated
tanager's rarity, it has been recommended that no further specimen
collection of the species occur (Collar et al. 1992, p. 896). However
we do not have specific information as to the level of specimen
collection, scientific research, or birding that occurs. Although the
removal or dispersal of any individuals or even a slight decline in the
species' fitness due to any intentional or inadvertent disturbances
would represent significant risks to the cherry-throated tanager's
overall viability (see Factor E), we are not aware of any information
currently available that indicates overutilization of the cherry-
throated tanager for commercial, recreational, scientific, or
educational purposes is occurring. As a result, we are not considering
overutilization to be a contributing factor to the continued existence
of the cherry-throated tanager.
C. Disease or Predation
Large, stable populations of wildlife species have adapted to
natural levels of disease and predation within their historic ranges.
However, the extant population of the cherry-throated tanager is
considered to be extremely small, highly fragmented, and declining,
making it particularly vulnerable to slight levels of disease and
predation.
Extensive human activity in previously undisturbed or isolated
areas can lead to the introduction and spread of exotic diseases, some
of which (e.g., West Nile virus) can negatively impact endemic bird
populations (Naugle et al. 2004, p. 704; Neotropical News 2003, p. 1).
It can also result in altered predator populations and the introduction
of exotic predator species, some of which (e.g., feral cats (Felis
catus) and rats (Ratus sp.)) can be especially harmful to populations
of endemic bird species (American Bird Conservancy 2007, p. 1;
Courchamp et al. 1999, p. 219; Duncan and Blackburn 2007, pp. 149-150;
Salo et al. 2007, pp. 1241-1242; Small 2005, p. 257). Any additive
mortality to the cherry-throated tanager population or a decrease in
its fitness due to an increase in the incidence of disease or predation
would represent significant risks to the species' overall viability
(see Factor E). However, while these potential influences remain a
concern for future management of the species, we are not aware of any
information currently available that indicates the occurrence of
disease in the cherry-throated tanager, or that documents any predation
incurred by the species. As a result, we are not considering disease or
predation to be a contributing factor to the continued existence of the
cherry-throated tanager.
D. The Inadequacy of Existing Regulatory Mechanisms
The cherry-throated tanager is formally recognized as
``endangered'' in Brazil (Order No. 1.522) and is directly protected by
various laws promulgated by the Brazilian government (BLI 2007, p. 2;
Collar et al. 1992, p. 896; ECOLEX 2007, pp. 1-2). For example, there
are measures that prohibit, or regulate through Federal agency
oversight, the following activities with regard to endangered species:
export and international trade (e.g., Decree No.
[[Page 40663]]
76.623, Order No. 419-P), hunting (e.g., Act No. 5.197), collection and
research (Order No. 332), captive propagation (Order No. 5), and
general harm (e.g., Decree No. 3.179).
In addition, there are a wide range of regulatory mechanisms in
Brazil that indirectly protect the cherry-throated tanager through
measures that protect its remaining suitable habitat (ECOLEX 2007, pp.
2-5). For example, there are measures that: (1) Prohibit exploitation
of the remaining primary forests within the Atlantic Forest biome
(e.g., Decree No. 750, Resolution No. 10); (2) govern various practices
associated with the management of primary and secondary forests, such
as logging, charcoal production, reforestation, recreation, and water
resources (e.g., Resolution No. 9, Act No. 4.771, Decree No. 1.282,
Decree No. 3.420, Order No. 74-N, Act No. 7.803); (3) establish
provisions for controlling forest fires (e.g., Decree No. 97.635, Order
No. 231-P, Order No. 292-P, Decree No. 2.661); and (4) regulate
industrial developments, such as hydroelectric plants and biodiesel
production (e.g., Normative Instruction No. 65, Law No. 11.116).
Finally, there are various measures (e.g., Law No. 11.516, Act No.
7.735, Decree No. 78, Order No. 1, Act No. 6.938) that direct Federal
and state agencies to promote the protection of lands and natural
resources under their jurisdictions (ECOLEX 2007, pp. 5-6).
There are also various regulatory mechanisms in Brazil that govern
the formal establishment and management of protected areas to promote
conservation of the country's natural resources (ECOLEX 2007, pp. 6-7).
These mechanisms generally aim to protect endangered wildlife and plant
species, genetic resources, overall biodiversity, and native ecosystems
on Federal, state, and privately owned lands (e.g., Law No. 9.985, Law
No. 11.132, Resolution No. 4, Decree No. 1.922). Brazil's formally
established protection areas are categorized based on their overall
management objectives (e.g., National Parks versus Biological Reserves)
and, based on those categories, allow varying uses and provide varying
levels of protection for specific resources (Costa 2007, pp. 5-19).
Few sites have recent confirmed observations of the cherry-throated
tanager. There have been possible sightings of the cherry-throated
tanager in the Augusto Ruschi Biological Reserve (also known as Nova
Lombardia Biological Reserve), which comprises approximately 5,000
hectares (ha) (12,355 acres (ac)) in Espiritu Santo; however, there is
doubt that the species occupies the reserve due to a lack of records by
ornithologists, since the 1970s, of birds that frequent the area (BLI
2007, p. 2; Bauer et al. 2000, p. 106; Scott 1997, p. 62). One of the
key sites still occupied by the species is the Pindobas IV Farm. It has
been recommended that the farm be formally designated as a protected
area to help ensure the species' future protection, and the owners of
this farm have expressed interest in this recommendation (Bauer et al.
2000, p. 106; BLI 2007g, p. 2). Under Brazilian law, the remaining
native forest on the owner's land could be designated as a Private
Natural Heritage Reserve.
For various reasons (e.g., lack of funding, personnel, or local
management commitment), some of Brazil's protected areas exist without
the current capacity to achieve their stated natural resource
objectives (ADEJA 2007, pp. 1-2; Bruner et al. 2001, p. 125; Costa
2007, p. 7; IUCN 1999, pp. 23-24; Neotropical News 1996, pp. 9-10;
Neotropical News 1999, p. 9). Enforcement has been a challenge to
implement. Therefore, even with the further designation of protected
areas, it is unlikely that all of the identified resource concerns for
the cherry-throated tanager (e.g., residential and agricultural
encroachment, resource extraction, unregulated tourism, and grazing)
would be sufficiently addressed at these sites.
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil (Brannstrom
2000, p. 326; Butler 2007, p. 3; Conservation International 2007c, p.
1; Pivello 2007, p. 2; Ratter et al. 1997, pp. 227-228; Saatchi et al.
2001, p. 874). More recently, the Brazilian government has given
greater recognition to the environmental consequences of such rapid
expansion, and has taken steps to better manage some of the natural
resources potentially impacted (Butler 2007, p. 7; Costa 2007, p. 7;
Neotropical News 1997a, p. 10; Neotropical News 1997b, p. 11;
Neotropical News 1998b, p. 9; Neotropical News 2003, p. 13; Nunes and
Kraas 2000, p. 45; Venturini et al. 2005, p. 68). Despite these
efforts, pressures to develop areas containing cherry-throated tanager
habitat continue (ADEJA 2007, pp. 1-2; BLI 2007d, p. 2; Tobias and
Williams 1996, p. 65).
Summary of Factor D
Brazil is faced with competing priorities of encouraging
development for economic growth and resource protection. Although there
are various government-sponsored measures that remain in place in
Brazil that continue to facilitate development projects, there are also
a wide variety of regulatory mechanisms in Brazil that require
protection of the cherry-throated tanager and its habitat throughout
the species' potentially occupied range. Due to competing priorities,
threats to the species' remaining habitat are ongoing (see Factor A).
Therefore, when combined with Factors A and E, we find that the
existing regulatory mechanisms are inadequate to ameliorate the current
threats to the cherry-throated tanager throughout its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the cherry-throated
tanager. In basic terms, demographic stochasticity is defined by chance
changes in the population growth rate for the species (Gilpin and
Soul[eacute] 1986, p. 27). Population growth rates are influenced by
individual birth and death rates (Gilpin and Soul[eacute] 1986, p. 27),
immigration and emigration rates, as well as changes in population sex
ratios. Natural variation in survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27). Genetic stochasticity is caused by changes in gene
frequencies due to genetic drift, and diminished genetic diversity,
and/or effects due to inbreeding (i.e., inbreeding depression) (Lande
1995, p. 786). Inbreeding can have individual or population-level
consequences either by increasing the phenotypic expression (the
outward appearance or observable structure, function or behavior of a
living organism) of recessive, deleterious alleles or by reducing the
overall fitness of individuals in the population (Charlesworth and
Charlesworth 1987, p. 231; Shaffer 1981, p. 131). Environmental
stochasticity is defined as the susceptibility of small, isolated
populations of wildlife species to natural levels of environmental
variability and related ``catastrophic'' events (e.g., severe storms,
prolonged drought, extreme cold spells, wildfire) (Dunham et al. 1999,
p. 9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). Each risk
will be analyzed specifically for the cherry-throated tanager.
Small, isolated populations of wildlife species are susceptible to
demographic
[[Page 40664]]
and genetic problems (Shaffer 1981, pp. 130-134). These threat factors,
which may act in concert, include: Natural variation in survival and
reproductive success of individuals, chance disequilibrium of sex
ratios, changes in gene frequencies due to genetic drift, diminished
genetic diversity and associated effects due to inbreeding (i.e.,
inbreeding depression), dispersal of just a few individuals, a few
clutch failures, a skewed sex ratio in recruited offspring over just
one or a few years, and chance mortality of just a few reproductive-age
individuals.
The cherry-throated tanager is believed to have been rare
historically with a naturally patchy, low density distribution, as
indicated by the paucity of confirmed sightings of this colorful bird
in areas that have been heavily visited by experienced birders (Bauer
et al. 2000, p. 98; Collar et al. 1994, p. 190; Venturini et al. 2005,
pp. 63-64; BLI 2007g, p. 1). However, the species must have maintained
a minimum level of genetic interchange among its local subpopulations
in order for them to have persisted (Middleton and Nisbet 1997, p. 107;
Vil[agrave] et al. 2002, p. 91; Wang 2004, p. 332).
In the absence of more species-specific life history data, a
general approximation of a minimum viable population size is referred
to as the 50/500 rule (Franklin 1980, p. 147), as described under
Factor E of the Brazilian merganser. Currently, the cherry-throated
tanager is only known from two occupied sites where an approximate
total of 14 birds have been observed since 1998 (Venturini et al. 2005,
p. 66). Given this information, current population estimates are 50 to
249 individuals, or below (BLI 2007g, p. 1; Venturini et al. 2005, p.
66). The lower limit of the population is at or below the minimum
number of individuals required to avoid imminent risks from inbreeding
(Ne = 50). The current maximum estimate of 249 individuals
for the entire population is only half of the upper threshold
(Ne = 500) required to maintain genetic diversity over time
and to maintain an enhanced capacity to adapt to changing conditions.
As such, we currently consider the species to be at risk due to its
lack of near- and long-term genetic viability.
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the cherry-throated tanager (see Factors A and
D). We expect that any additional loss or degradation of habitats that
are used by the cherry-throated tanager will have disproportionately
greater impacts on the species due to the population's fragmented
state. This is because with each contraction of an existing
subpopulation, the likelihood of interchange with other subpopulations
within patches decreases, while the likelihood of its complete
reproductive isolation increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986, p. 31).
Without efforts to maintain buffer areas and reconnect some of the
remaining tracts of suitable habitat near the species' currently
occupied sites, it is doubtful that the individual tracts are currently
large enough to support viable populations of many birds endemic to the
Atlantic Forest, and the eventual loss of any small, isolated
populations appears to be inevitable (Goerck 1997, p. 117; Harris and
Pimm 2004, pp. 1609-1610; IUCN 1999, pp. 23-24; Machado and Da Fonseca
2000, pp. 914, 921-922; Saatchi et al. 2001, p. 873; Scott and Brooke
1985, p. 118). Furthermore, as a species' status continues to decline,
often as a result of deterministic forces such as habitat loss or
overutilization, it will become increasingly vulnerable to a broad
array of other forces. If this trend continues, its ultimate extinction
due to one or more stochastic events becomes more likely.
We expect that the cherry-throated tanager's increased
vulnerability to demographic stochasticity and inbreeding will be
operative even in the absence of any human-induced threats or
stochastic environmental events, which only act to further exacerbate
the species' vulnerability to local extirpations and eventual
extinction. Demographic and genetic stochastic forces typically operate
synergistically. Initial effects of one threat factor can later
exacerbate the effects of other threat factors, as well as itself
(Gilpin and Soul[eacute] 1986, pp. 25-26). For example, any further
fragmentation of populations will, by definition, result in the further
removal or dispersal of individuals, which will exacerbate the other
threats. Conversely, lack of a sufficient number of individuals in a
local area or a decline in their individual or collective fitness may
cause a decline in the population size, despite the presence of
suitable habitat patches.
Small, isolated populations of wildlife species, such as the
cherry-throated tanager, are also susceptible to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged drought, extreme cold spells, wildfire), which
we will refer to as environmental stochasticity (Dunham et al. 1999, p.
9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). A single
stochastic environmental event can severely reduce existing wildlife
populations and, if the affected population is already small or
severely fragmented, it is likely that demographic stochasticity or
inbreeding will become operative, which would place the population in
jeopardy (Gilpin and Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-
789).
Summary of Factor E
The small and declining numbers that make up the cherry-throated
tanager's population makes it susceptible to natural environmental
variability or chance events. In addition to its declining numbers, the
high level of population fragmentation makes the species susceptible to
genetic and demographic stochasticity. Therefore, we find that
demographic, genetic, and environmental stochastic events are a threat
to the continued existence of the cherry-throated tanager throughout
its range.
Status Determination for the Cherry-throated Tanager
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the cherry-throated tanager. The species is
currently at risk throughout all of its range due to ongoing threats of
habitat destruction and modification (Factor A), and its lack of near-
and long-term genetic viability due to threats associated with
demographic, genetic, and environmental stochasticity (Factor E).
Furthermore, we have determined that the existing regulatory mechanisms
(Factor D) are not adequate to ameliorate the current threats to the
cherry-throated tanager.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become
[[Page 40665]]
an endangered species within the foreseeable future throughout all or a
significant portion of its range.'' Based on the threats to the cherry-
throated tanager throughout its entire range, as described above, we
determine that the cherry-throated tanager is in danger of extinction
throughout all of its range. Therefore, on the basis of the best
available scientific and commercial information, we are proposing to
list the cherry-throated tanager as an endangered species throughout
all of its range.
IV. Fringe-backed Fire-eye (Pyriglena atra)
Species Description
The fringe-backed fire-eye has distinctive red eyes and measures
approximately 17.5 cm (7 in). Males are black with a small patch on
their backs of black feathers lined with white edges. Females are more
of a reddish-brown color, with a black tail, brown underparts and a
whitish throat (BLI 2007e, p. 1).
Taxonomy
The fringe-backed fire-eye belongs in the ``antbird'' family
Thamnophilidae, and was first described by Swainson in 1825 (BLI 2007e,
p. 1). Sick (1991, p. 416) describes this species to be similar to the
white-backed fire-eye (Pyriglena leuconota). The fringe-backed fire-eye
was previously referred to as Swainson's fire-eye, and is also called
``Alapi noir'' in French, ``Fleckenmantel-Feuerauge'' in German, and
``Ojodefuego de Bah[iacute]a'' in Spanish (del Hoyo 2003, p. 637).
Habitat and Life History
The fringe-backed fire-eye is endemic to the Atlantic Forest biome
and typically inhabits dense understories at the edges of lowland
primary tropical forests (BLI 2007e, p. 2; Collar et al. 1992, p. 677;
del Hoyo et al. 2003, p. 637). The species has also been found to
occupy degraded forests and dense understories of secondary-growth
forest stands. It can also occupy early-successional forest stands, but
avoids any areas with open understories (e.g., sunny openings, interior
forest) (del Hoyo et al. 2003, p. 637).
The fringe-backed fire-eye forages in dense, tangled vegetation
with numerous horizontal perches within approximately 3 m (10 ft) of
the ground, although it occasionally feeds higher up (ca. 10 m (33 ft))
(Collar et al. 1992, p. 677; del Hoyo et al. 2003, p. 637). The species
typically occurs as individual birds, in closely associated pairs, or
in small family groups. The bird often relies on army ant (Eciton sp.)
swarms to flush their prey, which may include cockroaches (superfamily
Blattoidea), grasshoppers (family Acrididae), winged ants (class
Chilopoda), caterpillars (order Lepidoptera), and geckos (family
Gekkonidae) (del Hoyo et al. 2003, pp. 637-638; Sick 1993, pp. 403-
404).
Limited specific information is known about the species' breeding
behavior (del Hoyo et al. 2003, p. 638). However, females of this genus
typically lay two eggs in spherical nests that are approximately 10 cm
(4 in) in diameter, have a side entrance, and are attached to
vegetation within roughly 1 m (3.3 ft) of ground (Sick 1993, pp. 405-
406). In addition, both sexes in this genus typically help to build
nests, brood clutches, and attend their young (Sick 1993, pp. 405-406).
Range and Distribution
The fringe-backed fire-eye occurs along a narrow belt of coastal
forest habitats from southern Sergipe to northeastern Bahia, Brazil
(BLI 2007e, p. 1; Collar et al. 1992, p. 677; del Hoyo et al. 2003, p.
637; Sick 1993, p. 416). The species' entire population was previously
believed to be restricted to a few sites of remnant primary forest,
totaling roughly 9 km\2\ (3.5 mi\2\) in northeastern Bahia. In 2002,
approximately 18 individuals were observed in a forested site in
Sergipe (del Hoyo et al. 2003, p. 638). This discovery extended the
species' known range to the north by approximately 175 km (109 mi) (del
Hoyo et al. 2003, p. 638). However, the fringe-backed fire-eye has not
been located at several sites from where it was previously known in
Bahia (del Hoyo et al. 2003, p. 638).
Population Estimates
The fringe-backed fire-eye's extant population is estimated to be
between 1,000 and 2,499 individuals. The available information
indicates that the species' population is fragmented among 6 to 10
occupied areas, with the largest subpopulation between 50 and 249
individuals (BLI 2007e, p. 3). Its population, along with the extent
and quality of its habitat, continues to decline (BLI 2007e, p. 1).
Conservation Status
IUCN considers the fringe-backed fire-eye to be ``Endangered''
because it has ``a very small fragmented range, within which the extent
and quality of its habitat are continuing to decline and where it is
only known from a few localities'' (BLI 2007e, p. 1). In addition, the
species is protected under Brazilian law (Collar et al. 1992, p. 678).
Summary of Factors Affecting the Fringe-backed Fire-eye
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
The fringe-backed fire-eye occurs in one of the most densely
populated regions of Brazil, and most of the tropical forest habitats
believed to have been used historically by the species have been
converted or are severely degraded due to the wide range of human
activities (BLI 2003a, p. 4; BLI 2007e, p. 2; Collar and Andrew 1988,
p. 102; Collar et al. 1992, p. 678; Collar et al. 1994, p. 135;
Conservation International 2007a, p. 1; del Hoyo et al. 2003, p. 638;
H[ouml]fling 2007, p. 1; The Nature Conservancy 2007, p. 1; Sick 1993,
p. 407; World Wildlife Fund 2007, pp. 3-51). Based on a number of
recent estimates, 92 to 95 percent of the area (over 1,250,000 km\2\
(482,628 mi\2\)) historically covered by tropical forests within the
Atlantic Forest biome has been converted or severely degraded as a
result of various human activities (Butler 2007, p. 2; Conservation
International 2007a, p. 1; H[ouml]fling 2007, p. 1; IUCN 1999;
Morellato and Haddad 2000, p. 786; Myers et al. 2000, pp. 853-854; The
Nature Conservancy 2007, p. 1; Saatchi et al. 2001, p. 868; World
Wildlife Fund 2007, pp. 2-41). The current rate of habitat decline
within the Atlantic Forest biome is unknown.
In addition to the overall loss and degradation of native habitat
within this biome, the remaining tracts of habitat are severely
fragmented. The region has the two largest cites in Brazil, S[atilde]o
Paulo and Rio de Janeiro, and is home to approximately 70 percent of
Brazil's 169 million people (CEPF 2002; IBGE 2007). The major human
activities that have resulted in the loss, degradation, and
fragmentation of native habitats within the Atlantic Forest biome
include extensive establishment of agricultural fields (e.g., soy
beans, sugarcane, and corn), plantations (e.g., eucalyptus, pine,
coffee, cocoa, rubber, and bananas), livestock pastures, centers of
human habitation, and industrial developments (e.g., charcoal
production, steel plants, and hydropower reservoirs). Forestry
practices (e.g., commercial logging), subsistence activities (e.g.,
fuelwood collection), and changes in fire frequencies also contribute
to the degradation of the native habitat (BLI 2003a, p. 4;
J[uacute]nior et al. 1995, p. 147; The Nature Conservancy 2007, p. 2;
Nunes and Kraas 2000, p. 44; Peixoto and Silva 2007, p. 5; Saatchi et
al. 2001, pp. 868-869; Scott and Brooke 1985,
[[Page 40666]]
p. 118; World Wildlife Fund 2007, pp. 3-51).
The fringe-backed fire-eye is not strictly tied to primary forest
habitats and can make use of early-successional, secondary-growth
forests with dense understory vegetation (BLI 2007e, p. 2; Collar et
al. 1992, p. 677; del Hoyo et al. 2003, p. 637). However, this does not
necessarily lessen the risk to the species from the effects of
deforestation and habitat degradation. Atlantic Forest birds, such as
the fringe-backed fire-eye, which are tolerant of secondary-growth
forests, are also rare or have severely restricted ranges (i.e., less
than 21,000 km\2\ (8,100 mi\2\)). Thus habitat degradation can
adversely impact such species as equally as it impacts primary forest-
obligate species (Harris and Pimm 2004, pp. 1612-1613). The entire
range of the fringe-backed fire-eye encompasses approximately 4,990
km\2\ (1,924 mi\2\), with only 20 percent of this area considered
occupied (BLI 2007e, pp. 1-4).
The susceptibility to extirpation of limited-range species that are
tolerant of secondary-growth forests or other disturbed sites can occur
for a variety of reasons, such as when a species' remaining population
is already too small or its distribution too fragmented such that it
may not be demographically or genetically viable (Harris and Pimm 2004,
pp. 1612-1613). In addition, while the fringe-backed fire-eye may be
tolerant of secondary-growth forests or other disturbed sites, these
areas may not represent optimal conditions for the species, which would
include dense understories and abundant prey species. For example,
management of plantations often involves intensive control of the
site's understory vegetation and long-term use of pesticides, which
eventually result in severely diminished understory cover and potential
prey species (Rolim and Chiarello 2004, pp. 2687-2691; Saatchi et al.
2001, pp. 868-869; Scott and Brooke 1985, p. 118). Such management
practices eventually result in the loss of native understory plant
species, creating relatively open understories, which the fringe-backed
fire-eye avoids (BLI 2007e, p. 2; Collar et al. 1992, p. 677; del Hoyo
et al. 2003, p. 637).
Secondary impacts that are associated with the above human
activities that fragment the remaining tracks of Atlantic forest used
by the fringe-backed fire-eye include the potential introduction of
disease vectors or exotic predators within the species' historic range
(see Factor C). As a result of these secondary impacts, there is often
a time lag between the initial conversion or degradation of suitable
habitats and the extinction of endemic bird populations (Brooks et al.
1999a, p. 1; Brooks et al. 1999b, p. 1140). Even when potentially
occupied sites may be formally protected (see Factor D), the remaining
fragments of forested habitat will likely undergo further degradation
due to their altered dynamics and isolation (through infestation of
gap-opportunistic species, which alter forest structure, and decrease
in gene flow between species) (Tabanez and Viana 2000, pp. 929-932).
Therefore, even without further habitat loss or degradation, the
fringe-backed fire-eye remains at risk from past impacts to its
suitable habitats.
Summary of Factor A
Most of the tropical forest habitats believed to have been used
historically by the fringe-backed fire-eye have been converted or are
severely degraded due to the above human activities (BLI 2003a, p. 4;
BLI 2007e, p. 2; Collar and Andrew 1988, p. 102; Collar et al. 1992, p.
678; Collar et al. 1994, p. 135; Conservation International 2007a, p.
1; del Hoyo et al. 2003, p. 638; H[ouml]fling 2007, p. 1; The Nature
Conservancy 2007, p. 1; Sick 1993, p. 407; World Wildlife Fund 2007,
pp. 3-51). In addition, the remaining tracts of suitable habitat
potentially used by the species, including many secondary-growth
forests, are subject to ongoing clearing for agriculture fields and
plantations (e.g., sugar cane and oil palm), livestock pastures, and
industrial and residential developments (Collar and Andrew 1988, p.
102; Collar et al. 1992, p. 678).
Even with the recent passage of national forest policy and in the
face of many other legal protections in Brazil (see Factor D), the rate
of habitat loss throughout the Atlantic Forest biome has increased
since the mid-1990s (CEPF 2001, p. 10; Hodge et al. 1997, p. 1; Rocha
et al. 2005, p. 270), and native habitats at many of the remaining
sites may be lost over the next several years (Rocha et al. 2005, p.
263). Furthermore, because the species' extant population is already
small, highly fragmented, and believed to be declining (BLI 2007e, p.
1), any further loss or degradation of its remaining suitable habitat
represent significant threat to the species (see Factor E). Therefore,
we find that destruction and modification of habitat are threats to the
continued existence of the fringe-backed fire-eye throughout its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The extant population of the fringe-backed fire-eye is considered
to be small, fragmented, and declining. Therefore, the removal or
dispersal of just a few individuals from any of the species'
subpopulations or even a slight decline in their fitness due to
intentional or inadvertent hunting or specimen collection could
represent a significant threat to the fringe-backed fire-eye's overall
viability (see Factor E). However, while these potential influences
remain a concern for future management of the species, we are not aware
of any information currently available that indicates that this species
is being used for any commercial, recreational, scientific, or
educational purpose. As a result, we are not considering
overutilization to be a contributing factor to the continued existence
of the fringe-backed fire-eye.
C. Disease or Predation
Extensive human activity in previously undisturbed or isolated
areas can lead to the introduction and spread of exotic diseases, some
of which (e.g., West Nile virus) can negatively impact endemic bird
populations (Naugle et al. 2004, p. 704; Neotropical News 2003, p. 1).
It can also result in altered predator populations and the introduction
of exotic predator species, some of which (e.g., feral cats (Felis
catus) and rats (Ratus sp.)) can be especially harmful to populations
of endemic bird species (American Bird Conservancy 2007, p. 1;
Courchamp et al. 1999, p. 219; Duncan and Blackburn 2007, pp. 149-150;
Salo et al. 2007, pp. 1241-1242; Small 2005, p. 257).
Although large, stable populations of wildlife species have adapted
to natural levels of disease and predation within their historic
ranges, the extant population of the fringe-backed fire-eye is
considered to be small, fragmented, and declining (BLI 2007e, p. 1).
Any additive mortality to the fringe-backed fire-eye's subpopulations
or a decrease in their fitness due to an increase in the incidence of
disease or predation could adversely impact the species' overall
viability (see Factor E). However, while these potential influences
remain a concern for future management of the species, we are not aware
of any information currently available that specifically indicates the
occurrence of disease in the fringe-backed fire-eye, or that documents
any predation incurred by the species. As a result, we are not
considering disease or predation to be a contributing factor to the
continued existence of the fringe-backed fire-eye.
D. The Inadequacy of Existing Regulatory Mechanisms
The fringe-backed fire-eye is formally recognized as ``endangered''
in Brazil
[[Page 40667]]
(Order No. 1.522) and is directly protected by various laws promulgated
by the Brazilian government (BLI 2007e, p. 2; Collar et al. 1992, p.
678; ECOLEX 2007, pp. 1-2). For example, there are measures that
prohibit, or regulate through Federal agency oversight, the following
activities with regard to endangered species: Export and international
trade (e.g., Decree No. 76.623, Order No. 419-P), hunting (e.g., Act
No. 5.197), collection and research (Order No. 332), captive
propagation (Order No. 5), and general harm (e.g., Decree No. 3.179).
In addition, there are a wide range of regulatory mechanisms in Brazil
that indirectly protect the fringe-backed fire-eye through measures
that protect its remaining suitable habitat (ECOLEX 2007, pp. 2-5). For
example, there are measures that: (1) Prohibit exploitation of the
remaining primary forests within the Atlantic Forest biome (e.g.,
Decree No. 750, Resolution No. 10); (2) govern various practices
associated with the management of primary and secondary forests, such
as logging, charcoal production, reforestation, recreation, and water
resources (e.g., Resolution No. 9, Act No. 4.771, Decree No. 1.282,
Decree No. 3.420, Order No. 74-N, Act No. 7.803); (3) establish
provisions for controlling forest fires (e.g., Decree No. 97.635, Order
No. 231-P, Order No. 292-P, Decree No. 2.661); and (4) regulate
industrial developments, such as hydroelectric plants and biodiesel
production (e.g., Normative Instruction No. 65, Law No. 11.116).
Finally, there are various measures (e.g., Law No. 11.516, Act No.
7.735, Decree No. 78, Order No. 1, Act No. 6.938) that direct Federal
and state agencies to promote the protection of lands and natural
resources under their jurisdictions (ECOLEX 2007, pp. 5-6).
There are also various regulatory mechanisms in Brazil that govern
the formal establishment and management of protected areas to promote
conservation of the country's natural resources (ECOLEX 2007, pp. 6-7).
These mechanisms generally aim to protect endangered wildlife and plant
species, genetic resources, overall biodiversity, and native ecosystems
on Federal, State, and privately owned lands (e.g., Law No. 9.985, Law
No. 11.132, Resolution No. 4, Decree No. 1.922). Brazil's formally
established protection areas are categorized based on their overall
management objectives (e.g., National Parks versus Biological
Reserves), and based on those categories they allow varying uses and
provide varying levels of protection for specific resources (Costa
2007, pp. 5-19).
Currently, the fringe-backed fire-eye does not occur within any
protected areas, although it has been recommended that some of the key
sites it still occupies should be formally designated as protected
areas to help ensure the species' future protection (BLI 2007e, p. 2;
Collar et al. 1992, p. 678; del Hoyo et al. 2003, p. 638). However, for
various reasons (e.g., lack of funding, personnel, or local management
commitment), some of Brazil's protected areas exist without the current
capacity to achieve their stated natural resource objectives (Bruner et
al. 2001, p. 125; Costa 2007, p. 7; IUCN 1999, pp. 23-24; Neotropical
News 1996, pp. 9-10; Neotropical News 1999, p. 9). Therefore, even with
any future designation of protected areas, it is unlikely that all of
the identified resource concerns for the fringe-backed fire-eye (e.g.,
residential and agricultural encroachment, resource extraction,
unregulated tourism, and grazing) would be sufficiently addressed at
these sites.
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil (Brannstrom
2000, p. 326; Butler 2007, p. 3; Conservation International 2007c, p.
1; Pivello 2007, p. 2; Ratter et al. 1997, pp. 227-228; Saatchi et al.
2001, p. 874). More recently, the Brazilian government has given
greater recognition to the environmental consequences of such rapid
expansion, and has taken steps to better manage some of the natural
resources potentially impacted (Butler 2007, p. 7; Costa 2007, p. 7;
Neotropical News 1997a, p. 10; Neotropical News 1997b, p. 11;
Neotropical News 1998b, p. 9; Neotropical News 2003, p. 13; Nunes and
Kraas 2000, p. 45). Despite these efforts, development projects
continue to degrade and clear potentially occupied habitat for
plantations within the Atlantic Forest biome (Butler 2007, p. 3; Collar
et al. 1992, p. 678; Neotropical News 1998a, p. 10; Ratter et al. 1997,
pp. 227-228; Saatchi et al. 2001, p. 874).
Summary of Factor D
Brazil is faced with competing priorities of encouraging
development for economic growth and resource protection. Although there
are various government-sponsored measures that remain in place in
Brazil that continue to facilitate potentially harmful development
projects, there are also a wide variety of regulatory mechanisms in
Brazil that require protection of the fringe-backed fire-eye and its
habitat throughout the species' potentially occupied range. Due to
competing priorities, significant threats to the species' remaining
habitat are ongoing (see Factor A). Therefore, when combined with
Factors A and E, we find that the existing regulatory mechanisms are
inadequate to ameliorate the current threats to the fringe-backed fire-
eye throughout its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the fringe-backed
fire-eye. In basic terms, demographic stochasticity is defined by
chance changes in the population growth rate for the species (Gilpin
and Soul[eacute] 1986, p. 27). Population growth rates are influenced
by individual birth and death rates (Gilpin and Soul[eacute] 1986, p.
27), immigration and emigration rates, as well as changes in population
sex ratios. Natural variation in survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27). Genetic stochasticity is caused by changes in gene
frequencies due to genetic drift, and diminished genetic diversity,
and/or effects due to inbreeding (i.e., inbreeding depression) (Lande
1995, p. 786). Inbreeding can have individual or population-level
consequences either by increasing the phenotypic expression (the
outward appearance or observable structure, function or behavior of a
living organism) of recessive, deleterious alleles or by reducing the
overall fitness of individuals in the population (Charlesworth and
Charlesworth 1987, p. 231; Shaffer 1981, p. 131). Environmental
stochasticity is defined as the susceptibility of small, isolated
populations of wildlife species to natural levels of environmental
variability and related ``catastrophic'' events (e.g., severe storms,
prolonged drought, extreme cold spells, wildfire) (Dunham et al. 1999,
p. 9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). Each risk
will be analyzed specifically for the fringe-backed fire-eye.
Small, isolated populations of wildlife species are susceptible to
demographic and genetic problems (Shaffer 1981, pp. 130-134). These
threat factors, which may act in concert, include: Natural variation in
survival and reproductive success of individuals, chance disequilibrium
of sex ratios, changes in
[[Page 40668]]
gene frequencies due to genetic drift, diminished genetic diversity and
associated effects due to inbreeding (i.e., inbreeding depression),
dispersal of just a few individuals, a few clutch failures, a skewed
sex ratio in recruited offspring over just one or a few years, and
chance mortality of just a few reproductive-age individuals.
There is very little information available regarding the historic
abundance and distribution of the fringe-backed fire-eye. However, the
species' historic population was likely larger and more widely
distributed than today (BLI 2007e, p. 1), and it must have maintained a
minimum level of genetic interchange among its local subpopulations in
order for them to have persisted (Middleton and Nisbet 1997, p. 107;
Vila et al. 2002, p. 91; Wang 2004, p. 332).
In the absence of more species-specific life history data, the 50/
500 rule (as explained under Factor E for the Brazilian merganser) may
be used to approximate minimum viable population size (Franklin 1980,
p. 147). The available information indicates that the fringe-backed
fire-eye population is fragmented among 6 to 10 occupied areas, with
little likelihood for interchange of individuals among the species'
subpopulations (BLI 2007e, p. 3-4). The largest subpopulation is
estimated between 50 and 249 individuals, and therefore, it is at or
just below the minimum number of individuals required to avoid imminent
risks from inbreeding (Ne = 50). The current maximum
estimate of 249 individuals for the largest subpopulation (BLI 2007e,
p. 3) is only half of the upper threshold (Ne = 500)
required to maintain genetic diversity over time and to maintain an
enhanced capacity to adapt to changing conditions. As such, we
currently consider the species to be at risk due to its lack of near-
and long-term genetic viability.
Available information also indicates that suitable habitats
currently occupied by the fringe-backed fire-eye are highly fragmented
and that the species' extant population is small and declining. In
addition, the fringe-backed fire-eye has not been located at several
sites from where it was previously known in Bahia, and the
subpopulation recently discovered in Sergipe only included
approximately 18 individuals (del Hoyo et al. 2003, p. 638). Continued
loss of suitable habitats (see Factor A) will exacerbate fragmentation
of the remaining occupied patches and will act to further isolate the
species' subpopulations.
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the fringe-backed fire-eye (see Factors A and D).
We expect that any additional loss or degradation of habitats that are
used by the fringe-backed fire-eye will have disproportionately greater
impacts on the species due to the population's fragmented state. This
is because with each contraction of an existing subpopulation, the
likelihood of interchange with other subpopulations within patches
decreases, while the likelihood of its complete reproductive isolation
increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986, p. 31).
Without efforts to maintain buffer areas and reconnect some of the
remaining tracts of suitable habitat near the species' currently
occupied sites, it is doubtful that the individual tracts are currently
large enough to support viable populations of many birds endemic to the
Atlantic Forest, such as the fringe-backed fire-eye, and the eventual
loss of any small, isolated populations appears to be inevitable
(Goerck 1997, p. 117; Harris and Pimm 2004, pp. 1609-1610; IUCN 1999,
pp. 23-24; Machado and Da Fonseca 2000, pp. 914, 921-922; Saatchi et
al. 2001, p. 873; Scott and Brooke 1985, p. 118). Furthermore, as a
species' status continues to decline, often as a result of
deterministic forces such as habitat loss or overutilization, it will
become increasingly vulnerable to a broad array of other forces. If
this trend continues, its ultimate extinction due to one or more
stochastic events becomes more likely.
We expect that the fringe-backed fire-eye's increased vulnerability
to demographic stochasticity and inbreeding will be operative even in
the absence of any human-induced threats or stochastic environmental
events, which only act to further exacerbate the species' vulnerability
to local extirpations and eventual extinction. Demographic and genetic
stochastic forces typically operate synergistically. Initial effects of
one threat factor can later exacerbate the effects of other threat
factors, as well as itself (Gilpin and Soul[eacute] 1986, pp. 25-26).
For example, any further fragmentation of populations will, by
definition, result in the further removal or dispersal of individuals,
which will exacerbate the other threats. Conversely, lack of a
sufficient number of individuals in a local area or a decline in their
individual or collective fitness may cause a decline in the population
size, despite the presence of suitable habitat patches.
Small, isolated populations of wildlife species, such as the
fringe-backed fire eye, are also susceptible to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged drought, extreme cold spells, wildfire), which
we will refer to as environmental stochasticity (Dunham et al. 1999, p.
9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). A single
stochastic environmental event can severely reduce existing wildlife
populations and, if the affected population is already small or
severely fragmented, it is likely that demographic stochasticity or
inbreeding will become operative, which would place the population in
jeopardy (Gilpin and Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-
789).
Summary of Factor E
The small and declining numbers that make up the fringe-backed
fire-eye's population makes it susceptible to natural environmental
variability or chance events. In addition to its declining numbers, the
high level of population fragmentation makes the species susceptible to
genetic and demographic stochasticity. Therefore, we find that
demographic, genetic, and environmental stochastic events are a threat
to the continued existence of the fringe-backed fire-eye throughout its
range.
Status Determination for the Fringe-Backed Fire-Eye
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the fringe-backed fire-eye. The species is
currently at risk throughout all of its range due to ongoing threats of
habitat destruction and modification (Factor A), and its lack of near-
and long-term genetic viability due to threats associated with
demographic, genetic, and environmental stochasticity (Factor E).
Furthermore, we have determined that the existing regulatory mechanisms
[[Page 40669]]
(Factor D) are not adequate to ameliorate the current threats to the
species.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Based on the threats to the fringe-backed fire-eye throughout
its entire range, as described above, we determine that the fringe-
backed fire-eye is in danger of extinction throughout all of its range.
Therefore, on the basis of the best available scientific and commercial
information, we are proposing to list the fringe-backed fire-eye as an
endangered species throughout all of its range.
V. Kaempfer's Tody-tyrant (Hemitriccus kaempferi)
Species Description
The Kaempfer's tody-tyrant is an olive-green bird measuring 10 cm
(4 in) (BLI 2007f, p. 1). The head and face have olive-brown coloring,
while the upper parts and breast are a dull olive-green, the underparts
are a pale greenish-yellow, and the throat is a pale yellow color. The
primary wings are dark and the secondary wings have greenish-yellow
borders. Each eye has a pale ring (BLI 2007f, p. 1).
Taxonomy
The Kaempfer's tody-tyrant is a member of the flycatcher family
(Tyrannidae) (BLI 2007f, p. 1). The species was previously recognized
under the genus Idioptilon, and was first described by Zimmer in 1953
(BLI 2007f, p. 1).
Habitat and Life History
The Kaempfer's tody-tyrant is endemic to the Atlantic Forest biome
and inhabits well shaded edges of medium-height (ca. 12 to 15 m (39 to
49 ft)) primary- and secondary-growth forests that are typically in
close proximity to rivers. The species appears to avoid tall, mature,
primary forest habitats (Barnett et al. 2000, pp. 372-373; BLI 2007f,
pp. 1-2; Collar et al. 1992, p. 776). The Kaempfer's tody-tyrant feeds
predominantly in the outer canopies of trees within roughly 1 to 3 m
(3.3 to 10 ft) of the ground, but may also feed higher up (ca. 6 m (20
ft)).
There is little information available describing the diet of the
Kaempfer's tody-tyrant; however, similar species within the Tyrannidae
family feed on a variety of insects, which they often catch while in
flight (Sick 1993, pp. 452-453). Breeding pairs typically forage
together and appear to maintain small, well-defined, permanent
territories (Barnett et al. 2000, p. 373; BLI 2007f, p. 2).
Both sexes help to build their nests, which can be located up to
approximately 6 m (20 ft) above the ground and 2-3 m (6.6-10 ft) within
the primary forest margin. Nests resemble elongated cups that can be up
to 45 cm (18 in) long and are made of live mosses, grass, and dead
leaves wrapped around a horizontal branch near the main trunk (Barnett
et al. 2000, p. 373).
Range and Distribution
The Kaempfer's tody-tyrant inhabits humid, lowland forests in
northeastern Santa Catarina, Brazil (Barnett et al. 2000, p. 371; BLI
2007f, p. 1; Collar et al. 1992, p. 776; Collar et al. 1994, p. 139).
The Kaempfer's tody-tyrant is only known with certainty from three
localities in the state of Santa Catarina: Brusque, Itapo[aacute], and
Vila Nova and nearby areas. The last record for Brusque is from 1950,
and the area has not been resurveyed since that time. The species has
not been located at Vila Nova since 1991, despite repeated searches
(BLI 2007f, pp. 1-2). The species was reported in 1998 and in 2000 in a
reserve called Reserva Particular do Patrimonio Natural de Ponta Velha
in Itapo[aacute]. This reserve is close to the state border with
Paran[aacute]; thus it is possible that the species may be found in
similar habitat in Paran[aacute]; however, surveys have not been
conducted (Barnett et al. 2000, p. 378).
Population Estimates
There is very little information currently available that
specifically addresses the Kaempfer's tody-tyrant's abundance; however,
its extant population is estimated to be between 1,000 and 2,499
individuals and is believed to be declining. The largest subpopulation
of the species is estimated to be between 250 and 1,000 individuals
(BLI 2007f, pp. 1-3).
Conservation Status
IUCN considers the Kaempfer's tody-tyrant to be ``Critically
Endangered'' because ``it is estimated to have an extremely small and
severely fragmented range, with recent records from only two locations,
and ongoing deforestation in the vicinity of these sites'' (BLI 2007f,
p. 1).
Summary of Factors Affecting the Kaempfer's Tody-tyrant
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Based on a number of recent estimates, 92 to 95 percent of the area
historically covered by tropical forests within the Atlantic Forest
biome has been converted or severely degraded as a result of various
human activities (Butler 2007, p. 2; Conservation International 2007a,
p. 1; H[ouml]fling 2007, p. 1; Morellato and Haddad 2000, p. 786; Myers
et al. 2000, pp. 853-854; The Nature Conservancy 2007, p. 1; Saatchi et
al. 2001, p. 868; World Wildlife Fund 2007, pp. 2-41). In addition to
the overall loss and degradation of native habitat within this biome,
the remaining tracts of habitat are severely fragmented. The current
rate of deforestation of Brazil's Atlantic Forest is unknown.
The region has the two largest cites in Brazil, S[atilde]o Paulo
and Rio de Janeiro, and is home to approximately 70 percent of Brazil's
169 million people (CEPF 2002; IBGE 2007). The major human activities
that have resulted in the loss, degradation, and fragmentation of
native habitats within the Atlantic Forest biome include extensive
establishment of agricultural fields (e.g., soy beans, sugarcane, and
corn), plantations (e.g., eucalyptus, pine, coffee, cocoa, rubber, and
bananas), livestock pastures, centers of human habitation, and
industrial developments (e.g., charcoal production, steel plants, and
hydropower reservoirs). Forestry practices (e.g., commercial logging),
subsistence activities (e.g., fuelwood collection), and changes in fire
frequencies also contribute to the degradation of the native habitat
(BLI 2003a, p. 4; J[uacute]nior et al. 1995, p. 147; The Nature
Conservancy 2007, p. 2; Nunes and Kraas 2000, p. 44; Peixoto and Silva
2007, p. 5; Saatchi et al. 2001, pp. 868-869; Scott and Brooke 1985, p.
118; World Wildlife Fund 2007, pp. 3-51).
The Kaempfer's tody-tyrant is not strictly tied to primary forest
habitats and can inhabit secondary-growth forests (Barnett et al. 2000,
pp. 372-373; BLI 2007f, pp. 1-2; Collar et al. 1992, p. 776). However,
this does not lessen the threat to the species from the effects of
ongoing deforestation and habitat degradation. Atlantic Forest birds,
such as the Kaempfer's tody-tyrant, which are tolerant of secondary-
growth forests, are also rare or have restricted ranges (i.e., less
than 21,000 km\2\ (8,100 mi\2\)). Thus, habitat degradation can
adversely impact such species just as equally as it
[[Page 40670]]
impacts primary forest-obligate species (Harris and Pimm 2004, pp.
1612-1613). Currently, the entire known range of the Kaempfer's tody-
tyrant is restricted to only 19 km\2\ (7.3 mi\2\) (BLI 2007f, p. 3).
The susceptibility to extirpation of rare, limited-range species
that are tolerant of secondary-growth forests occurs for a variety of
reasons such as when a species' remaining population is already too
small or its distribution too fragmented such that it may not be
demographically or genetically viable (Harris and Pimm 2004, pp. 1612-
1613). In addition, while the Kaempfer's tody-tyrant may be tolerant of
secondary-growth forests or other disturbed sites, these areas may not
represent optimal conditions for the species. For example, management
of plantations often involves intensive control of the site's
understory vegetation and long-term use of pesticides, which eventually
result in severely diminished understory cover and potential prey
species (Rolim and Chiarello 2004, pp. 2687-2691; Saatchi et al. 2001,
pp. 868-869; Scott and Brooke 1985, p. 118). Such management practices
eventually result in the loss of native understory plant species and
relatively open understories. Insectivorous birds that feed in the
understory, including those in the genus Hemitriccus, are especially
vulnerable to such habitat modifications (Goerck 1997, p. 117), and the
Kaempfer's tody-tyrant does not occupy these types of altered sites
(Barnett et al. 2000, p. 377).
Even when potentially occupied sites may be formally protected (see
Factor D), the remaining fragments of forested habitat will likely
undergo further degradation due to their altered dynamics and isolation
as defined by decreased gene flow, increase in inbreeding, decrease in
species fitness, increase in liana infestation, and dominance of gap-
obligate species (Tabanez and Viana 2000, pp. 929-932). Moreover,
secondary impacts that are associated with human activities that
degrade and remove native habitats within the Atlantic Forest biome
include the potential introduction of disease vectors or exotic
predators within the species' historic range (see Factor C). As a
result of these secondary impacts, there is often a time lag between
the initial conversion or degradation of suitable habitats and the
extinction of endemic bird populations (Brooks et al. 1999a, p. 1;
Brooks et al. 1999b, p. 1140). Therefore, even without further habitat
loss or degradation, the Kaempfer's tody-tyrant remains at risk from
past impacts to its suitable forested habitats.
Summary of Factor A
The Kaempfer's tody-tyrant occurs in one of the most densely
populated regions of Brazil, and most of the tropical forest habitats
believed to have been used historically by the species have been
converted or are severely degraded due to the wide range of human
activities identified above (Barnett et al. 2000, pp. 377-378; BLI
2003a, p. 4; BLI 2007f, p. 2; Collar et al. 1992, p. 776; Collar et al.
1994, p. 139; Conservation International 2007a, p. 1; H[ouml]fling
2007, p. 1; The Nature Conservancy 2007, p. 1; World Wildlife Fund
2007, pp. 3-51). In addition, the remaining tracts of suitable habitat
potentially used by the species, including many secondary-growth
forests, are subject to ongoing clearing for agricultural fields,
plantations (e.g., banana, palmetto, and rice), logging, livestock
pastures, and industrial and residential developments (Barnett et al.
2000, pp. 377-378; BLI 2007f, p. 4; Collar et al. 1992, p. 776).
Even with the recent passage of national forest policy and in light
of many other legal protections in Brazil (see Factor D), the rate of
habitat loss throughout the Atlantic Forest biome has increased since
the mid-1990s (CEPF 2001, p. 10; Hodge et al. 1997, p. 1; Rocha et al.
2005, p. 270), and native habitats at many of the remaining sites may
be lost over the next several years (Rocha et al. 2005, p. 263). In
addition, because the extant population of the Kaempfer's tody-tyrant
is already small, highly fragmented, and believed to be declining (BLI
2007f, pp. 1-3), any further loss or degradation of its remaining
suitable habitat will adversely impact the species. Therefore, we find
that destruction and modification of habitat are threats to the
continued existence of the Kaempfer's tody-tyrant throughout its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The extant population of the Kaempfer's tody-tyrant is considered
to be small, fragmented, and declining. Therefore, the removal or
dispersal of just a few individuals from any of the species'
subpopulations or even a slight decline in their fitness due to
intentional or inadvertent hunting, specimen collection, or other human
disturbances (e.g., scientific research, birding) could represent a
significant threat to the species' overall viability (see Factor E).
However, while these potential influences remain a concern for future
management of the Kaempfer's tody-tyrant, we are not aware of any
information currently available that indicates the use of this species
for any commercial, recreational, scientific, or educational purpose.
As a result, we are not considering overutilization to be a
contributing factor to the continued existence of the Kaempfer's tody-
tyrant.
C. Disease or Predation
Extensive human activity in previously undisturbed or isolated
areas can lead to the introduction and spread of exotic diseases, some
of which (e.g., West Nile virus) can negatively impact endemic bird
populations (Naugle et al. 2004, p. 704; Neotropical News 2003, p. 1).
It can also result in altered predator populations and the introduction
of various exotic predator species, some of which (e.g., feral cats
(Felis catus) and rats (Ratus sp.)) can be especially harmful to
populations of endemic bird species (American Bird Conservancy 2007, p.
1; Courchamp et al. 1999, p. 219; Duncan and Blackburn 2007, pp. 149-
150; Salo et al. 2007, pp. 1241-1242; Small 2005, p. 257). Although
large, stable populations of wildlife species have adapted to natural
levels of disease and predation within their historic ranges, the
extant population of the Kaempfer's tody-tyrant is considered to be
small, fragmented, and declining (BLI 2007f, pp. 1-3). In addition,
extensive human activity in previously undisturbed or isolated areas
can lead to the introduction and spread of exotic diseases, some of
which (e.g., West Nile virus) can negatively impact endemic bird
populations (Naugle et al. 2004, p. 704; Neotropical News 2003, p. 1).
Any additive mortality to the subpopulations of the Kaempfer's
tody-tyrant or a decrease in their fitness due to an increase in the
incidence of disease or predation could severely impact the species'
overall viability (see Factor E). However, while these potential
influences remain a concern for future management of the species, we
are not aware of any information currently available that indicates the
occurrence of disease in the Kaempfer's tody-tyrant, or that documents
any predation incurred by the species. As a result, we are not
considering disease or predation to be a contributing factor to the
continued existence of the Kaempfer's tody-tyrant.
D. The Inadequacy of Existing Regulatory Mechanisms
The Kaempfer's tody-tyrant is formally recognized as ``endangered''
in Brazil (Order No. 1.522) and is directly protected by various laws
promulgated by the Brazilian government (Barnett et al. 2000, p. 377;
BLI 2007f, p. 2; Collar
[[Page 40671]]
et al. 1992, p. 776; ECOLEX 2007, pp. 1-2). For example, there are
measures that prohibit, or regulate through Federal agency oversight,
the following activities with regard to endangered species: export and
international trade (e.g., Decree No. 76.623, Order No. 419-P), hunting
(e.g., Act No. 5.197), collection and research (Order No. 332), captive
propagation (Order No. 5), and general harm (e.g., Decree No. 3.179).
In addition, there are a wide range of regulatory mechanisms in Brazil
that indirectly protect the Kaempfer's tody-tyrant through measures
that protect its remaining suitable habitat (ECOLEX 2007, pp. 2-5). For
example, there are measures that: (1) Prohibit exploitation of the
remaining primary forests within the Atlantic Forest biome (e.g.,
Decree No. 750, Resolution No. 10); (2) govern various practices
associated with the management of primary and secondary forests, such
as logging, charcoal production, reforestation, recreation, and water
resources (e.g., Resolution No. 9, Act No. 4.771, Decree No. 1.282,
Decree No. 3.420, Order No. 74-N, Act No. 7.803); (3) establish
provisions for controlling forest fires (e.g., Decree No. 97.635, Order
No. 231-P, Order No. 292-P, Decree No. 2.661); and (4) regulate
industrial developments, such as hydroelectric plants and biodiesel
production (e.g., Normative Instruction No. 65, Law No. 11.116).
Finally, there are various measures (e.g., Law No. 11.516, Act No.
7.735, Decree No. 78, Order No. 1, Act No. 6.938) that direct Federal
and state agencies to promote the protection of lands and natural
resources under their jurisdictions (ECOLEX 2007, pp. 5-6).
Various regulatory mechanisms in Brazil govern the formal
establishment and management of protected areas to promote conservation
of the country's natural resources (ECOLEX 2007, pp. 6-7). These
mechanisms generally aim to protect endangered wildlife and plant
species, genetic resources, overall biodiversity, and native ecosystems
on Federal, state, and privately owned lands (e.g., Law No. 9.985, Law
No. 11.132, Resolution No. 4, Decree No. 1.922). Brazil's formally
established protection areas are categorized based on their overall
management objectives (e.g., National Parks versus Biological Reserves)
and, based on those categories, they allow varying uses and provide
varying levels of protection for specific resources (Costa 2007, pp. 5-
19).
Currently, the Kaempfer's tody-tyrant is known to occur within one
15 km\2\ (6 mi\2\) protected area, the privately owned Volta Velha
Natural Heritage Reserve (Barnett et al. 2000, pp. 377-378; BLI 2007f,
p. 3; Collar et al. 1992, p. 776). In addition, the species is known to
occur in forested habitat adjacent to another 4 km\2\ (1.5 mi\2\)
protected area, the Bracinho State Ecological Station, which was
established as a water-catchment buffer zone for a hydroelectric plant.
It has been recommended that both of these sites should be expanded to
ensure that the species' currently occupied range and other potentially
suitable habitats are encompassed within protected areas (Barnett et
al. 2000, pp. 377-378; BLI 2007f, p. 3; Collar et al. 1992, p. 776).
However, for various reasons (e.g., lack of funding, personnel, or
local management commitment), some of Brazil's protected areas exist
without the current capacity to achieve their stated natural resource
objectives (ADEJA 2007, pp. 1-2; Bruner et al. 2001, p. 125; Costa
2007, p. 7; IUCN 1999, pp. 23-24; Neotropical News 1996, pp. 9-10;
Neotropical News 1999, p. 9). Therefore, even with the expansion or
further designation of protected areas, it is unlikely that all of the
identified impacts to the Kaempfer's tody-tyrant (e.g., residential and
agricultural encroachment, resource extraction, unregulated tourism,
and grazing) would be sufficiently addressed at these sites.
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil (Brannstrom
2000, p. 326; Butler 2007, p. 3; Conservation International 2007c, p.
1; Pivello 2007, p. 2; Ratter et al. 1997, pp. 227-228; Saatchi et al.
2001, p. 874). More recently, the Brazilian government has given
greater recognition to the environmental consequences of such rapid
expansion, and has taken steps to better manage some of the natural
resources potentially impacted (Butler 2007, p. 7; Costa 2007, p. 7;
Neotropical News 1997a, p. 10; Neotropical News 1997b, p. 11;
Neotropical News 1998b, p. 9; Neotropical News 2003, p. 13; Nunes and
Kraas 2000, p. 45). However, there are still various government-
sponsored measures in place, both at the national and state levels,
that help facilitate development projects (Barnett et al. 2000, pp.
377-378; Butler 2007, p. 3; Collar et al. 1992, p. 776; Neotropical
News 1998a, p. 10; Ratter et al. 1997, pp. 227-228; Saatchi et al.
2001, p. 874) some of which, such as continued logging, housing and
tourism developments, and expansion of plantations, could impact
potentially important sites for the Kaempfer's tody-tyrant (Barnett et
al. 2000, p. 377-378; Collar et al. 1992, p. 776).
Summary of Factor D
Although there are government-sponsored measures that remain in
place in Brazil that continue to facilitate development projects, there
are also a wide variety of regulatory mechanisms in Brazil that require
protection of the Kaempfer's tody-tyrant and its habitat throughout the
species' potentially occupied range. However, the existing regulatory
mechanisms that apply to the species have proven difficult to enforce
(BLI 2003a, p. 4; Conservation International 2007c, p. 1; Costa 2007,
p. 7; The Nature Conservancy 2007, p. 2; Neotropical News 1997b, p. 11;
Peixoto and Silva 2007, p. 5; Scott and Brooke 1985, pp. 118, 130). As
a result, significant threats to the species' remaining habitats are
ongoing (see Factor A) due to competing priorities. Therefore, when
combined with Factors A and E, we find that the existing regulatory
mechanisms are inadequate to ameliorate the current threats to the
Kaempfer's tody-tyrant throughout its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the Kaempfer's tody-
tyrant. In basic terms, demographic stochasticity is defined by chance
changes in the population growth rate for the species (Gilpin and
Soul[eacute] 1986, p. 27). Population growth rates are influenced by
individual birth and death rates (Gilpin and Soul[eacute] 1986, p. 27),
immigration and emigration rates, as well as changes in population sex
ratios. Natural variation in survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27). Genetic stochasticity is caused by changes in gene
frequencies due to genetic drift, and diminished genetic diversity,
and/or effects due to inbreeding (i.e., inbreeding depression) (Lande
1995, p. 786). Inbreeding can have individual or population-level
consequences either by increasing the phenotypic expression (the
outward appearance or observable structure, function or behavior of a
living organism) of recessive, deleterious alleles or by reducing the
overall fitness of individuals in the population (Charlesworth and
Charlesworth 1987, p. 231; Shaffer 1981,
[[Page 40672]]
p. 131). Environmental stochasticity is defined as the susceptibility
of small, isolated populations of wildlife species to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged drought, extreme cold spells, wildfire)
(Dunham et al. 1999, p. 9; Mangel and Tier 1994, p. 612; Young 1994,
pp. 410-412). Each risk will be analyzed specifically for the
Kaempfer's tody-tyrant.
Small, isolated populations of wildlife species are susceptible to
demographic and genetic problems (Shaffer 1981, pp. 130-134). These
threat factors, which may act in concert, include: Natural variation in
survival and reproductive success of individuals, chance disequilibrium
of sex ratios, changes in gene frequencies due to genetic drift,
diminished genetic diversity and associated effects due to inbreeding
(i.e., inbreeding depression), dispersal of just a few individuals, a
few clutch failures, a skewed sex ratio in recruited offspring over
just one or a few years, and chance mortality of just a few
reproductive-age individuals.
There is very little information available regarding the historic
distribution and abundance of the Kaempfer's tody-tyrant. However, the
species' historic population was likely larger and more widely
distributed than today, and it must have maintained a minimum level of
genetic interchange among its local subpopulations in order for them to
have persisted (Middleton and Nisbet 1997, p. 107; Vil[agrave] et al.
2002, p. 91; Wang 2004, p. 332).
In the absence of more species-specific life history data, a
general approximation of a minimum viable population size is referred
to as the 50/500 rule (Franklin 1980, p. 147), as described under
Factor E for the Brazilian merganser. The extant population of the
Kaempfer's tody-tyrant is estimated to be between 1,000 and 2,499
individuals that are fragmented among several potentially occupied
sites, with the largest subpopulation estimated to be between 250 and
1,000 individuals (BLI 2007f, p. 3). The other subpopulations are even
smaller in size, and there is currently little likelihood for
interchange of individuals among them. The largest subpopulation
exceeds the minimum number of individuals required to avoid imminent
risks from inbreeding (Ne = 50), but may be only half of the
upper threshold (Ne = 500) required to maintain genetic
diversity and the capacity to adapt to changing conditions over time.
Continued loss of suitable habitats (see Factor A) will exacerbate
fragmentation of the remaining occupied patches and will act to further
isolate the species' subpopulations. As such, we currently consider the
species to be at risk due to its lack of long-term genetic viability.
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the Kaempfer's tody-tyrant (see Factors A and D).
We expect that any additional loss or degradation of habitats that are
used by the Kaempfer's tody-tyrant will have disproportionately greater
impacts on the species due to the population's fragmented state. This
is because with each contraction of an existing subpopulation, the
likelihood of interchange with other subpopulations within patches
decreases, while the likelihood of its complete reproductive isolation
increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986, p. 31).
Without efforts to maintain buffer areas and reconnect some of the
remaining tracts of suitable habitat near the species' currently
occupied sites, it is doubtful that the individual tracts are currently
large enough to support viable populations of many birds endemic to the
Atlantic Forest, like the Kaempfer's tody-tyrant, and the eventual loss
of any small, isolated populations appears to be inevitable (Goerck
1997, p. 117; Harris and Pimm 2004, pp. 1609-1610; IUCN 1999, pp. 23-
24; Machado and Da Fonseca 2000, pp. 914, 921-922; Saatchi et al. 2001,
p. 873; Scott and Brooke 1985, p. 118). Furthermore, as a species'
status continues to decline, often as a result of deterministic forces
such as habitat loss or overutilization, it will become increasingly
vulnerable to a broad array of other forces. If this trend continues,
its ultimate extinction due to one or more stochastic events becomes
more likely.
We expect that the Kaempfer's tody-tyrant's increased vulnerability
to demographic stochasticity and inbreeding will be operative even in
the absence of any human-induced threats or stochastic environmental
events, which only act to further exacerbate the species' vulnerability
to local extirpations and eventual extinction. Demographic and genetic
stochastic forces typically operate synergistically. Initial effects of
one threat factor can later exacerbate the effects of other threat
factors, as well as itself (Gilpin and Soul[eacute] 1986, pp. 25-26).
For example, any further fragmentation of populations will, by
definition, result in the further removal or dispersal of individuals,
which will exacerbate the other threats. Conversely, lack of a
sufficient number of individuals in a local area or a decline in their
individual or collective fitness may cause a decline in the population
size, despite the presence of suitable habitat patches.
Small, isolated populations of wildlife species, such as the
Kaempfer's tody-tyrant, are also susceptible to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged drought, extreme cold spells, wildfire), which
we will refer to as environmental stochasticity (Dunham et al. 1999, p.
9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). A single
stochastic environmental event can severely reduce existing wildlife
populations and, if the affected population is already small or
severely fragmented, it is likely that demographic stochasticity or
inbreeding will become operative, which would place the population in
jeopardy (Gilpin and Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-
789).
Summary of Factor E
The small and declining numbers that make up the Kaempfer's tody-
tyrant's population makes it susceptible to natural environmental
variability or chance events. In addition to its declining numbers, the
high level of population fragmentation makes the species susceptible to
genetic and demographic stochasticity. Therefore, we find that
demographic, genetic, and environmental stochastic events are a threat
to the continued existence of the Kaempfer's tody-tyrant throughout its
range.
Status Determination for the Kaempfer's Tody-tyrant
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the Kaempfer's tody-tyrant. The species is
currently at risk throughout all of its range due to ongoing threats of
habitat destruction and modification (Factor A), and its lack of long-
term genetic
[[Page 40673]]
viability due to threats associated with demographic, genetic, and
environmental stochasticity (Factor E). Furthermore, we have determined
that the existing regulatory mechanisms (Factor D) are not adequate to
ameliorate the current threats to the Kaempfer's tody-tyrant.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Based on the threats to the Kaempfer's tody-tyrant throughout
its entire range, as described above, we determine that the Kaempfer's
tody-tyrant is in danger of extinction throughout all of its range.
Therefore, on the basis of the best available scientific and commercial
information, we are proposing to list the Kaempfer's tody-tyrant as an
endangered species throughout all of its range.
VI. Margaretta's Hermit (Phaethornis malaris margarettae)
Species Description
The Margaretta's hermit is a long-billed hummingbird. The average
bill length is 37 millimeters (mm) (1.5 in) and the average tail length
is 42 mm (1.7 in) (Hinkelmann 1996, pp. 122-123). Hinkelmann (1996, p.
147) describes the species to be morphologically similar to Phaethornis
margarettae bolvianus with a paler underside.
Taxonomy
The Margaretta's hermit is in the hummingbird family, Trochilidae.
Margaretta's hermit was first described as a new species in 1972 by A.
Ruschi (Sibley and Monroe 1990). This bird has variously been
considered a full species (Phaethornis margarettae) and placed as a
subspecies with the long-billed hermit (P. superciliosus). However, the
available information indicates that it is most appropriately
considered to be a subspecies of the great-billed hermit (P. malaris)
(del Hoyo et al. 1999, p. 543; Dickinson 2003, p. 256; Hinkelmann 1996,
pp. 125-135; Howard and Moore 1980, p. 205; ICBP 1981, p. 2; Sibley and
Monroe 1990, p. 143; Sick 1993, p. 341; Stiles 2005, pp. 1-5).
Habitat and Life History
The Margaretta's hermit is endemic to the Atlantic Forest biome and
is found in shrubby understories of primary- and secondary-growth
tropical, lowland rainforest (del Hoyo et al. 1999, p. 543; ICBP 1981,
p. 2; Hinkelmann 1996, pp. 133-140; Sibley and Monroe 1990, p. 143).
Hummingbirds feed on the nectar of a variety of plant species,
especially bromeliads, and often have a symbiotic relationship with
specific plants for which they function as pollinators (Buzato et al.
2000, p. 824; del Hoyo et al. 1999, p. 543; Sick 1993, pp. 324-326).
They also feed on a variety of small arthropods, which are an
especially important source of protein for raising their young.
Females typically lay two eggs and are solely responsible for
tending their young. Hummingbird nests are usually constructed on
vegetation of items such as detritus, webs, leaves, and animal hair
cemented together with regurgitated nectar and saliva (Sick 1993, pp.
330-331). Little is known of the subspecies' seasonal movements, but
its daily movements within a local area are likely associated with the
timing of flowering plants that are used for feeding (del Hoyo et al.
1999, p. 543; Sick 1993, pp. 324-336).
Range and Distribution
The Margaretta's hermit historically occurred in coastal forested
habitats from Penambuco to Esp[iacute]rito Santo, Brazil (del Hoyo et
al. 1999, p. 543; Hinkelmann 1996, pp. 132-135; Sibley and Monroe 1990,
p. 143). The last confirmed occurrence of the Margaretta's hermit is
from a relatively old (ca. 1978) sighting of the subspecies on a
privately-owned, remnant forest called Klabin Farm, which is located in
Esp[iacute]rito Santo which presently includes 40 km\2\ (15.46 mi\2\)
of land (ICBP 1981, p. 2). A portion of this area (ca. 15 km\2\ (5.79
mi\2\)) was designated as the C[oacute]rrego Grande Biological Reserve
in 1989 (Costa 2007, p. 20; Willis and Oniki 2002, p. 21). Margaretta's
hermit likely also occurred at the Sooretama Biological Reserve in
Esp[iacute]rito Santo until around 1977 (ICBP 1981, p. 2).
Population Estimates
Unknown, although likely to be small in light of the very limited
area the subspecies may occupy (ICBP 1981, p. 2).
Conservation Status
IUCN considers the Margaretta's hermit to be ``Endangered'' because
its extant population is believed to have an extremely restricted
distribution and it is likely very small, if it survives at all (ICBP
1981, p. 2). The species, as a whole, is listed under Appendix II of
the Convention on International Trade in Endangered Species of Wild
Fauna and Flora (CITES) (UNEP-World Conservation Monitoring Centre
(WCMC) 2009b). Appendix II includes species that are not necessarily
threatened with extinction, but may become so unless trade is subject
to strict regulation to avoid utilization becoming incompatible with
the species' survival.
Summary of Factors Affecting the Margaretta's Hermit
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Based on a number of recent estimates, 92 to 95 percent of the area
historically covered by tropical forests within the Atlantic Forest
biome has been converted or severely degraded as a result of various
human activities (Morellato and Haddad 2000, p. 786; Myers et al. 2000,
pp. 853-854; Saatchi et al. 2001, p. 868; Conservation International
2007a, p. 1; The Nature Conservancy 2007, p. 1; World Wildlife Fund
2007, pp. 2-41; H[ouml]fling 2007, p. 1; Butler 2007, p. 2). In
addition to the overall loss and degradation of native habitat within
this biome, the remaining tracts of habitat are severely fragmented.
The current rate of habitat loss in the Atlantic Forest biome is
unknown.
The region has the two largest cites in Brazil, S[atilde]o Paulo
and Rio de Janeiro, and is home to approximately 70 percent of Brazil's
169 million people (CEPF 2002; IBGE 2007). The major human activities
that have resulted in the loss, degradation, and fragmentation of
native habitats within the Atlantic Forest biome include extensive
establishment of agricultural fields (e.g., soy beans, sugarcane, and
corn), plantations (e.g., eucalyptus, pine, coffee, cocoa, rubber, and
bananas), livestock pastures, centers of human habitation, and
industrial developments (e.g., charcoal production, steel plants, and
hydropower reservoirs). Forestry practices (e.g., commercial logging),
subsistence activities (e.g., fuelwood collection), and changes in fire
frequencies also contribute to the degradation of native habitat (BLI
2003a, p. 4; J[uacute]nior et al. 1995, p. 147; The Nature Conservancy
2007, p. 2; Nunes and Kraas 2000, p. 44; Peixoto and Silva 2007, p. 5;
Saatchi et al. 2001, pp. 868-869; Scott and Brooke 1985, p. 118; World
Wildlife Fund 2007, pp. 3-51).
Most of the tropical forest habitats believed to have been used
historically by the Margaretta's hermit have been converted or are
severely degraded due to the above human activities, and the subspecies
can not occupy these extensively altered areas (del Hoyo et al. 1999,
p. 543; ICBP 1981, p. 2; Scott and
[[Page 40674]]
Brooke 1985, p. 118; Sick 1993, p. 338). While the Margaretta's hermit
is not strictly tied to primary forest habitats and can make use of
secondary-growth forests, this does not lessen the threat to the
subspecies from the effects of deforestation and habitat degradation.
Atlantic Forest birds, such as Margaretta's hermit, which are tolerant
of secondary-growth forests, are also rare or have restricted ranges
(i.e., less than 21,000 km\2\ (8,100 mi\2\)). Thus, habitat degradation
can adversely impact such species just as equally as it impacts primary
forest obligate species (Harris and Pimm 2004, pp. 1612-1613). The last
site known to be occupied by the Margaretta's hermit totaled only about
40 km\2\ (15 mi\2\) (ICBP 1981, p. 2).
The susceptibility to extirpation of rare, limited-range species
that are tolerant of secondary-growth forests occurs for a variety of
reasons such as when a species' remaining population is already too
small or its distribution too fragmented such that it may not be
demographically or genetically viable (Harris and Pimm 2004, pp. 1612-
1613). In addition, while the Margaretta's hermit may be tolerant of
secondary-growth forests, these areas may not represent optimal
conditions for the species. For example, many hummingbird species are
susceptible to excessive sun and readily abandon their nests at altered
forested sites with too much exposure (Sick 1993, p. 331), as can occur
with various human activities that result in partial clearing (e.g.,
selective logging). In addition, management of plantations often
involves intensive control of the site's understory vegetation, which
eventually results in severely diminished understory cover (Rolim and
Chiarello 2004, pp. 2679-2680; Saatchi et al. 2001, pp. 868-869). Even
if the forest canopy structure remains largely intact, such management
practices eventually result in loss of native understory plant species
and severely altered understory structure and dynamics, which can be
especially detrimental to pollinator species such as the Margaretta's
hermit.
Even when forested lands are formally protected (see Factor D), the
remaining fragments of habitat where the subspecies may still occur
will likely continue to undergo degradation due to their altered
dynamics and isolation (Tabanez and Viana 2000, pp. 929-932). Moreover,
secondary impacts that are associated with human activities that
degrade the remaining tracts of forested habitat potentially used by
the subspecies include the potential introduction of disease vectors or
exotic predators within the subspecies' historic range (see Factor C).
As a result of these secondary impacts, there is often a time lag
between the initial conversion or degradation of suitable habitats and
the extinction of endemic bird populations (Brooks et al. 1999a, p. 1;
Brooks et al. 1999b, p. 1140). Therefore, even without further habitat
loss or degradation, the Margaretta's hermit remains at risk from past
impacts to its suitable forested habitats.
Summary of Factor A
The Margaretta's hermit occurs in one of the most densely populated
regions of Brazil, and human activities and their secondary impacts
identified above continue to threaten the last known tracts of habitat
within the Atlantic Forest biome that may still harbor the Margaretta's
hermit (BLI 2003a, p. 4; Conservation International 2007a, p. 1; del
Hoyo et al. 1999, p. 543; H[ouml]fling 2007, p. 1; ICBP 1981, p. 2; The
Nature Conservancy 2007, p. 1; Sick 1993, p. 338; World Wildlife Fund
2007, pp. 3-51). Even with the recent passage of national forest policy
and in light of many other legal protections in Brazil (see Factor D),
the rate of habitat loss throughout the Atlantic Forest biome has
increased since the mid-1990s (CEPF 2001, p. 10; Hodge et al. 1997, p.
1; Rocha et al. 2005, p. 270), and native habitats at many of the
remaining sites may be lost over the next several years (Rocha et al.
2005, p. 263). The Margaretta's hermit has already been reduced to such
an extent that it is now only known from a relatively old (ca. 1978)
sighting (ICBP 1981, p. 2; Willis and Oniki 2002, p. 21) and any
further loss or degradation of its remaining suitable habitat could
cause the extinction of this subspecies. Therefore, we find that
destruction and modification of habitat are threats to the continued
existence of the Margaretta's hermit throughout its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
In the past, many species of hummingbirds that occur in
southeastern Brazil were collected for use in the fashion industry due
to their colorful plumage, and populations of some species have been
extirpated or remain severely diminished as a result (Sick 1993, pp.
337-338). Due to concerns about hummingbirds in international trade, in
1987, the entire family, Trochilidae, was listed in Appendix II of
CITES (UNEP-WCMC 2009b), a treaty that regulates international trade in
certain protected animal and plant species.
Appendix II of CITES includes species that, although not
necessarily threatened presently with extinction, may become so unless
the trade in specimens is strictly controlled. International trade in
specimens of Appendix-II species is authorized through permits or
certificates, once the granting authorities have ascertained certain
factors, including that trade will not be detrimental to the survival
of the species in the wild and that the specimen was legally acquired
(UNEP-WCMC 2009b).
Since the listing of the family under CITES in 1987, there have
been eight CITES-permitted international transactions in specimens of
the species Phaethornis malaris; however, no trade has been reported at
the subspecies level, Phaethornis malaris margarettae (John Caldwell,
UNEP-WCMC, pers. comm., May 13, 2008). According to WCMC, the eight
transactions involved a total of 30 specimens of Phaethornis malaris,
which were imported into the United States from the United Kingdom,
Peru and Suriname; the two latter countries are within the species'
range (John Caldwell, UNEP-WCMC, pers. comm., May 12, 2008). Due to the
suspected small population size and restricted range of the
Margaretta's hermit, we believe that the 30 specimens reported in trade
were of the species and not the subspecies. Furthermore, we are unaware
of any unreported CITES trade or illegal international trade in
specimens of Margaretta's hermit. Therefore, we believe that
international trade is not a factor influencing the subspecies' status
in the wild.
Local hummingbird populations may also be impacted by collection
for various uses, including scientific research, preparation of
``novelty'' exhibits, consumption in local dishes, and for the zoo or
pet trade (Rolim and Chiarello 2004, pp. 2679-2680; Scott and Brooke
1985, p. 118; Sick 1993, pp. 337-338).
If it exists at all, the extant population of the Margaretta's
hermit is likely extremely small and occurs within a severely
restricted range. Due to its rarity, the removal or dispersal of any
individuals of this subspecies or even a slight decline in the
population's fitness due to any intentional or inadvertent hunting and
specimen collection would adversely impact the subspecies' overall
viability (see Factor E). However, while these potential influences
remain a concern for future management of the Margaretta's hermit, we
are not aware of any information currently available that specifically
indicates the use of this subspecies for any commercial, recreational,
scientific, or educational purpose. As a result, we are not
[[Page 40675]]
considering overutilization to be a contributing factor to the
continued existence of the Margaretta's hermit.
C. Disease or Predation
Young hummingbirds are sometimes severely affected by botflies
(Philornis sp.) (Sick 1993, pp. 336-337). In addition, extensive human
activity in previously undisturbed or isolated areas can lead to the
introduction and spread of exotic diseases, some of which (e.g., West
Nile virus) can negatively impact endemic bird populations (Naugle et
al. 2004, p. 704; Neotropical News 2003, p. 1). With regard to
predation, a variety of reptiles (e.g., snakes, lizards) and predatory
birds (e.g., owls, hawks) are known to prey on hummingbirds (Sick 1993,
pp. 336-337). Furthermore, nestling hummingbirds can be killed by
raiding army ants (Eciton sp.), while some hornets and bees are
potential competitors for flower nectar and have been known to lethally
sting adult hummingbirds. In addition, extensive human activity in
previously undisturbed or isolated areas can result in altered predator
populations and the introduction of various exotic predator species,
some of which (e.g., feral cats (Felis catus) and rats (Ratus sp.)) can
be especially harmful to populations of endemic bird species (American
Bird Conservancy 2007, p. 1; Courchamp et al. 1999, p. 219; Duncan and
Blackburn 2007, pp. 149-150; Salo et al. 2007, pp. 1241-1242; Small
2005, p. 257).
Large, stable populations of wildlife species have adapted to
natural levels of disease and predation within their historic ranges.
However, the extant population of the Margaretta's hermit is considered
to be extremely small and occurs within a severely restricted range, if
it currently exists at all, and there is a greatly expanded human
population within the subspecies' historic distribution. Any additive
mortality to the Margaretta's hermit population or a decrease in its
fitness due to an increase in the incidence of disease or predation
would severely impact the subspecies' overall viability (see Factor E).
Nevertheless, while these potential influences remain a concern for
future management of the subspecies, we are not aware of any
information currently available that indicates the occurrence of
disease in the Margaretta's hermit, or that documents any predation
incurred by this subspecies. As a result, we are not considering
disease or predation to be a contributing factor to the continued
existence of the Margaretta's hermit.
D. The Inadequacy of Existing Regulatory Mechanisms
The Margaretta's hermit is formally recognized as ``endangered'' in
Brazil (Order No. 1.522) and is directly protected by various laws
promulgated by the Brazilian government (ECOLEX 2007, pp. 1-2; ICBP
1981, p. 2). For example, there are measures that prohibit, or regulate
through Federal agency oversight, the following activities with regard
to endangered species: export and international trade (e.g., Decree No.
76.623, Order No. 419-P), hunting (e.g., Act No. 5.197), collection and
research (Order No. 332), captive propagation (Order No. 5), and
general harm (e.g., Decree No. 3.179).
The Margaretta's hermit is listed in Appendix II of CITES (UNEP-
WCMC 2009b). CITES is an international treaty among 173 nations,
including Brazil and the United States, that entered into force in 1975
(UNEP-WCMC 2009a). In the United States, CITES is implemented through
the U.S. Endangered Species Act (Act). The Act designates the Secretary
of the Interior as the Scientific and Management Authorities to
implement the treaty with all functions carried out by the Service.
Under this treaty, countries work together to ensure that international
trade in animal and plant species is not detrimental to the survival of
wild populations by regulating the import, export, re-export, and
introduction from the sea of CITES-listed animal and plant species
(USFWS 2009). As discussed under Factor B, we do not consider
international trade to be a threat to the Margaretta's hermit.
Therefore, this international treaty does not reduce any current
threats to the subspecies. Any international trade that occurs in the
future would be effectively regulated under CITES.
There are also a wide range of regulatory mechanisms in Brazil that
indirectly protect the Margaretta's hermit through measures that
protect its remaining suitable habitat (ECOLEX 2007, pp. 2-5). For
example, there are measures that: (1) Prohibit exploitation of the
remaining primary forests within the Atlantic Forest biome (e.g.,
Decree No. 750, Resolution No. 10); (2) govern various practices
associated with the management of primary and secondary forests, such
as logging, charcoal production, reforestation, recreation, and water
resources (e.g., Resolution No. 9, Act No. 4.771, Decree No. 1.282,
Decree No. 3.420, Order No. 74-N, Act No. 7.803); (3) establish
provisions for controlling forest fires (e.g., Decree No. 97.635, Order
No. 231-P, Order No. 292-P, Decree No. 2.661); and (4) regulate
industrial developments, such as hydroelectric plants and biodiesel
production (e.g., Normative Instruction No. 65, Law No. 11.116).
Finally, there are various measures (e.g., Law No. 11.516, Act No.
7.735, Decree No. 78, Order No. 1, Act No. 6.938) that direct Federal
and state agencies to promote the protection of lands and natural
resources under their jurisdictions (ECOLEX 2007, pp. 5-6).
Various regulatory mechanisms exist in Brazil that govern the
formal establishment and management of protected areas to promote
conservation of the country's natural resources (ECOLEX 2007, pp. 6-7).
These mechanisms generally aim to protect endangered wildlife and plant
species, genetic resources, overall biodiversity, and native ecosystems
on Federal, state, and privately owned lands (e.g., Law No. 9.985, Law
No. 11.132, Resolution No. 4, Decree No. 1.922). Brazil's formally
established protection areas are categorized based on their overall
management objectives (e.g., National Parks versus Biological
Reserves), and based on those categories they allow varying uses and
provide varying levels of protection for specific resources (Costa
2007, pp. 5-19).
Successful efforts to protect the last site known to harbor the
Margaretta's hermit from further development occurred in the mid-1980s
(Pereira 2007, p. 2), and a portion of this area was designated as the
C[oacute]rrego Grande Biological Reserve in 1989 (Costa 2007, p. 20).
However, nearly the entire site burned in 1986, and the subspecies has
not been recorded there since that time (Willis and Oniki 2002, p. 21).
The Margaretta's hermit likely also occurred at the Sooretama
Biological Reserve in Esp[iacute]rito Santo in 1977 (ICBP 1981, p. 2).
For various reasons (e.g., lack of funding, personnel, or local
management commitment), some of Brazil's protected areas exist without
the current capacity to achieve their stated natural resource
objectives (Bruner et al. 2001, p. 125; Costa 2007, p. 7; IUCN 1999,
pp. 23-24; Neotropical News 1996, pp. 9-10; Neotropical News 1999, p.
9; Peixoto and Silva 2007, p. 5; World Wildlife Fund 2007, pp. 3-51).
For example, according to a World Wide Fund for Nature report, 47 of 86
management plans for protected areas that have been assessed are
considered to remain below their minimum level of implementation of
Federal requirements, with only 7 considered to be fully implemented
(Neotropical News 1999, p. 9). Therefore, even with formal designation
of protected areas, it is unlikely that all of the identified threats
to the Margaretta's hermit (e.g., residential and agricultural
[[Page 40676]]
encroachment, resource extraction, unregulated tourism, grazing, and
fire) are sufficiently addressed at these sites.
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil, which helped
facilitate the large-scale habitat conversions that have occurred
throughout the Atlantic Forest biome (Brannstrom 2000, p. 326; Butler
2007, p. 3; Conservation International 2007c, p. 1; Pivello 2007, p. 2;
Ratter et al. 1997, pp. 227-228; Saatchi et al. 2001, p. 874). More
recently, the Brazilian government has given greater recognition to the
environmental consequences of such rapid expansion, and has taken steps
to better manage some of the natural resources potentially impacted
(Butler 2007, p. 7; Costa 2007, p. 7; Neotropical News 1997a, p. 10;
Neotropical News 1997b, p. 11; Neotropical News 1998b, p. 9;
Neotropical News 2003, p. 13; Nunes and Kraas 2000, p. 45). However,
due to competing priorities, these regulatory mechanisms have proven
difficult to enforce.
Summary of Factor D
Although there are government-sponsored measures that remain in
place in Brazil that continue to facilitate potentially harmful
development projects, there are also a wide variety of regulatory
mechanisms in Brazil that require protection of the Margaretta's hermit
and its habitat throughout the subspecies' potentially occupied range.
The existing regulatory mechanisms that apply to the Margaretta's
hermit have been difficult to enforce (BLI 2003a, p. 4; Conservation
International 2007c, p. 1; Costa 2007, p. 7; The Nature Conservancy
2007, p. 2; Neotropical News 1997b, p. 11; Peixoto and Silva 2007, p.
5; Scott and Brooke 1985, pp. 118, 130). As a result, significant
threats to the subspecies' remaining habitats are ongoing (see Factor
A). Therefore, when combined with Factors A and E, we find that the
existing regulatory mechanisms are inadequate to ameliorate the current
threats to the Margaretta's hermit throughout its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the Margaretta's
hermit. In basic terms, demographic stochasticity is defined by chance
changes in the population growth rate for the species (Gilpin and
Soul[eacute] 1986, p. 27). Population growth rates are influenced by
individual birth and death rates (Gilpin and Soul[eacute] 1986, p. 27),
immigration and emigration rates, as well as changes in population sex
ratios. Natural variation in survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27). Genetic stochasticity is caused by changes in gene
frequencies due to genetic drift, and diminished genetic diversity,
and/or effects due to inbreeding (i.e., inbreeding depression) (Lande
1995, p. 786). Inbreeding can have individual or population-level
consequences either by increasing the phenotypic expression (the
outward appearance or observable structure, function or behavior of a
living organism) of recessive, deleterious alleles or by reducing the
overall fitness of individuals in the population (Charlesworth and
Charlesworth 1987, p. 231; Shaffer 1981, p. 131). Environmental
stochasticity is defined as the susceptibility of small, isolated
populations of wildlife species to natural levels of environmental
variability and related ``catastrophic'' events (e.g., severe storms,
prolonged drought, extreme cold spells, wildfire) (Young 1994, pp. 410-
412; Mangel and Tier 1994, p. 612; Dunham et al. 1999, p. 9). Each risk
will be analyzed specifically for the Margaretta's hermit.
Small, isolated populations of wildlife species are susceptible to
demographic and genetic problems (Shaffer 1981, pp. 130-134). These
threat factors, which may act in concert, include: natural variation in
survival and reproductive success of individuals, chance disequilibrium
of sex ratios, changes in gene frequencies due to genetic drift,
diminished genetic diversity and associated effects due to inbreeding
(i.e., inbreeding depression), dispersal of just a few individuals, a
few clutch failures, a skewed sex ratio in recruited offspring over
just one or a few years, and chance mortality of just a few
reproductive-age individuals.
Historically, the Margaretta's hermit population was more abundant
and widespread throughout its range (ICBP 1981, p. 2), and the
subspecies must have maintained a minimum level of genetic interchange
among its local subpopulations in order for them to have persisted
(Middleton and Nisbet 1997, p. 107; Vil[agrave] et al. 2002, p. 91;
Wang 2004, p. 332). In the absence of more species-specific life
history data, the 50/500 rule (as explained under Factor E for the
Brazilian merganser) may be used to approximate minimum viable
population size (Franklin 1980, p. 147). There are no specific past or
present abundance estimates for the Margaretta's hermit. However, the
available information indicates that its extant population, if it still
exists, is likely well below both of the thresholds (Ne = 50
and Ne = 500) for an effective population size because of
the very limited area that it is known to occupy (see Factor A) (ICBP
1981, p. 2). This means that the subspecies' population likely does not
have enough individuals to avoid risks from inbreeding or the ability
to maintain genetic diversity and adapt to changing conditions over
time. Furthermore, if the subspecies does still exist, continued loss
of suitable habitats (see Factor A) is likely to further exacerbate
fragmentation of any remaining occupied patches. As such, we currently
consider the subspecies to be at risk due to its lack of near- and
long-term genetic viability.
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the Margaretta's hermit (see Factors A and D). We
expect that any additional loss or degradation of habitats that are
used by the Margaretta's hermit will have disproportionately greater
impacts on the subspecies due to the population's fragmented state.
This is because with each contraction of an existing subpopulation, the
likelihood of interchange with other subpopulations within patches
decreases, while the likelihood of its complete reproductive isolation
increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986, p. 31).
Without efforts to maintain buffer areas and reconnect some of the
remaining tracts of suitable habitat near the subspecies' currently
occupied sites, it is doubtful that the individual tracts are currently
large enough to support viable populations of many birds endemic to the
Atlantic Forest, like the Margaretta's hermit, and the eventual
[[Page 40677]]
loss of any small, isolated populations appears to be inevitable
(Goerck 1997, p. 117; Harris and Pimm 2004, pp. 1609-1610; IUCN 1999,
pp. 23-24; Machado and Da Fonseca 2000, pp. 914, 921-922; Saatchi et
al. 2001, p. 873; Scott and Brooke 1985, p. 118). Furthermore, as a
species' status continues to decline, often as a result of
deterministic forces such as habitat loss or overutilization, it will
become increasingly vulnerable to a broad array of other forces. If
this trend continues, its ultimate extinction due to one or more
stochastic events becomes more likely.
We expect that the Margaretta's hermit's increased vulnerability to
demographic stochasticity and inbreeding will be operative even in the
absence of any human-induced threats or stochastic environmental
events, which only act to further exacerbate the subspecies'
vulnerability to local extirpations and eventual extinction.
Demographic and genetic stochastic forces typically operate
synergistically. Initial effects of one threat factor can later
exacerbate the effects of other threat factors, as well as itself
(Gilpin and Soul[eacute] 1986, pp. 25-26). For example, any further
fragmentation of populations will, by definition, result in the further
removal or dispersal of individuals, which will exacerbate the other
threats. Conversely, lack of a sufficient number of individuals in a
local area or a decline in their individual or collective fitness may
cause a decline in the population size, despite the presence of
suitable habitat patches.
Small, isolated populations of wildlife species, such as the
Margaretta's hermit, are also susceptible to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged drought, extreme cold spells, wildfire), which
we will refer to as environmental stochasticity (Dunham et al. 1999, p.
9; Mangel and Tier 1994, p. 612; Young 1994, pp. 410-412). A single
stochastic environmental event can severely reduce existing wildlife
populations and, if the affected population is already small or
severely fragmented, it is likely that demographic stochasticity or
inbreeding will become operative, which would place the population in
jeopardy (Gilpin and Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-
789).
Summary of Factor E
The small and declining numbers that make up the Margaretta's
hermit's population make it susceptible to natural environmental
variability or chance events. In addition to its declining numbers, the
high level of population fragmentation makes the subspecies susceptible
to genetic and demographic stochasticity. Therefore, we find that
demographic, genetic, and environmental stochastic events are a threat
to the continued existence of the Margaretta's hermit throughout its
range.
Status Determination for the Margaretta's Hermit
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the Margaretta's hermit. The subspecies is
currently at risk throughout all of its range due to ongoing threats of
habitat destruction and modification (Factor A), and its lack of near-
and long-term genetic viability due to threats associated with
demographic, genetic, and environmental stochasticity (Factor E).
Furthermore, we have determined that the existing regulatory mechanisms
(Factor D) are not adequate to ameliorate the current threats to the
Margaretta's hermit.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Based on the threats to the Margaretta's hermit throughout its
entire range, as described above, we determine that the Margaretta's
hermit is in danger of extinction throughout all of its range.
Therefore, on the basis of the best available scientific and commercial
information, we are proposing to list the Margaretta's hermit as an
endangered species throughout all of its range.
VII. Southeastern Rufous-vented Ground-cuckoo (Neomorphus geoffroyi
dulcis)
Species Description
The southeastern rufous-vented ground-cuckoo is a large-sized
terrestrial bird. The cuckoo has a distinctive flat frontal crest, a
long tail and long legs, and a yellow-green curved bill (Payne 2005, p.
206; Roth 1981, p. 388). The species is blackish-brown or reddish black
in color, and has brown scale-like coloring on the breast with a black
breast band and a reddish belly. It has a bare face with gray to blue
coloring (Payne 2005, p. 206).
Taxonomy
The southeastern rufous-vented ground-cuckoo is one of seven
subspecies of the rufous-vented ground-cuckoo (Neomorphus geoffroyi)
that occur at several disjunct localities from Nicaragua to central
South America (del Hoyo et al. 1997, pp. 606-607; Howard and Moore
1980, p. 178; Payne 2005, pp. 204-207; Sibley and Monroe 1990, p. 107).
Habitat and Life History
The southeastern rufous-vented ground-cuckoo is an extremely shy,
ground-foraging bird that requires large blocks of mature, undisturbed,
tropical lowland forest within the Atlantic Forest biome (del Hoyo et
al. 1997, pp. 606-607; ICBP 1981, p. 1; Sick 1993, p. 286; Payne 2005,
pp. 204-207). This species is unable to sustain flight for long
distances, and major rivers and other extensive areas of non-habitat
are thought to impede their movements.
Southeastern rufous-vented ground-cuckoos feed on large insects,
scorpions, centipedes, spiders, small frogs, lizards, and occasionally
on seeds and fruit. The species is agile when on the ground and highly
adept at running and jumping through branches in pursuit of prey (Sick
1993, p. 278). The species is often associated with army ant (Eciton
sp.) and red ant (Solenopsis sp.) colonies, whose foraying columns they
use as ``beaters'' to flush their prey (Sick 1993, p. 286). They are
also known to forage for flushed prey behind other species, such as the
white-lipped peccary (Tayassu pecari) (Sick 1993, p. 286).
Unlike some other species of cuckoos, southeastern rufous-vented
ground-cuckoos are not believed to be parasitic nesters and build their
own nests approximately 2.5 m (8 ft) up in the branches of swampy
vegetation (Roth 1981, p. 388; Sick 1993, p. 286). The species' nest
resembles a shallow bowl, roughly 25 cm (10 in) across, made of sticks
and lined with leaves. Once the young are fledged, the adults care for
them away from the nest site (del Hoyo et al. 1997, pp. 606-607).
Range and Distribution
Although the southeastern rufous-vented ground-cuckoo had a
widespread distribution historically, it has likely always been locally
rare (ICBP 1981, p. 1). Historic distributions included the Brazilian
cities of Bahia, Minas Gerais, Esp[iacute]rito Santo, and, possibly,
Rio de Janeiro (ICBP 1981, p. 1; Payne 2005, p. 207). The last
confirmed sighting of this subspecies was from Sooretama Biological
Reserve north of the Doce River in Esp[iacute]rito Santo in 1977, and
it may now be extinct (Payne 2005, p. 207; Roth 1981, p. 388; Scott and
Brooke 1985, pp. 125-126). However, a recent photographic record (ca.
2004) indicates
[[Page 40678]]
that the subspecies may still occur at Doce River State Park in Minas
Gerais (Scoss et al. 2006, p. 1).
Population Estimates
Unknown, although certainly very low if it still exists (ICBP 1981,
p. 1).
Conservation Status
IUCN considers the southeastern rufous-vented ground-cuckoo to be
``Endangered'' because although the subspecies was ``never numerous,
this extremely shy species is among the first to disappear if its
primary forest habitat is disturbed and in south-eastern Brazil where
it occurs, most of such forest has been destroyed'' (ICBP 1981, p. 1).
Summary of Factors Affecting the Southeastern Rufous-vented Ground-
cuckoo
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Based on a number of recent estimates, 92 to 95 percent of the area
historically covered by tropical forests within the Atlantic Forest
biome has been converted or severely degraded as a result of various
human activities (Butler 2007, p. 2; Conservation International 2007a,
p. 1; H[ouml]fling 2007, p. 1; Morellato and Haddad 2000, p. 786; Myers
et al. 2000, pp. 853-854; The Nature Conservancy 2007, p. 1; Saatchi et
al. 2001, p. 868; World Wildlife Fund 2007, pp. 2-41). In addition to
the overall loss and degradation of native habitat within this biome,
the remaining tracts of habitat are severely fragmented. The current
rate of habitat decline within the Atlantic Forest is unknown.
The region has the two largest cites in Brazil, S[atilde]o Paulo
and Rio de Janeiro, and is home to approximately 70 percent of Brazil's
169 million people (CEPF 2002; IBGE 2007). The major human activities
that have resulted in the loss, degradation, and fragmentation of
native habitats within the Atlantic Forest biome include extensive
establishment of agricultural fields (e.g., soy beans, sugarcane, and
corn), plantations (e.g., eucalyptus, pine, coffee, cocoa, rubber, and
bananas), livestock pastures, centers of human habitation, and
industrial developments (e.g., charcoal production, steel plants, and
hydropower reservoirs). Forestry practices (e.g., commercial logging),
subsistence activities (e.g., fuelwood collection), and changes in fire
frequencies also contribute to the destruction of native habitats (BLI
2003a, p. 4; J[uacute]nior et al. 1995, p. 147; The Nature Conservancy
2007, p. 2; Nunes and Kraas 2000, p. 44; Peixoto and Silva 2007, p. 5;
Saatchi et al. 2001, pp. 868-869; Scott and Brooke 1985, p. 118; World
Wildlife Fund 2007, pp. 3-51).
Most of the tropical forest habitats believed to have been used
historically by the southeastern rufous-vented ground-cuckoo have been
converted or severely degraded by the above human activities (del Hoyo
et al. 1997, pp. 606-607; ICBP 1981, p. 1; Payne 2005, p. 207; Scott
and Brooke 1985, p. 118; Sick 1993, p. 286). Terrestrial insectivorous
birds that are primary forest-obligate species, such as the
southeastern rufous-vented ground-cuckoo, are especially vulnerable to
habitat modifications (Goerck 1997, p. 116), and can not occupy these
extensively altered habitats.
Even when they are formally protected (see Factor D), the remaining
fragments of primary forest habitat where the subspecies may still
occur will likely undergo further degradation due to their altered
dynamics and isolation (Tabanez and Viana 2000, pp. 929-932).
In addition, secondary impacts that are associated with human
activities that cause severe fragmentation of the remaining tracts of
primary forest habitat potentially used by the subspecies include the
potential introduction of disease vectors or exotic predators within
the subspecies' historic range (see Factor C). As a result of the above
influences, there is often a time lag between the initial conversion or
degradation of suitable habitats and the extinction of endemic bird
populations (Brooks et al. 1999a, p. 1; Brooks et al. 1999b, p. 1140).
Therefore, even without further habitat loss or degradation, the
southeastern rufous-vented ground-cuckoo remains at risk from past
impacts to its primary forest habitats.
Summary of Factor A
The above human activities and their secondary impacts continue to
threaten the remaining tracts of habitat within the Atlantic Forest
biome that may still harbor the southeastern rufous-vented ground-
cuckoo (BLI 2003a, p. 4; Conservation International 2007a, p. 1; del
Hoyo et al. 1997, pp. 606-607; H[ouml]fling 2007, p. 1; The Nature
Conservancy 2007, p. 1; Payne 2005, p. 207; World Wildlife Fund 2007,
pp. 3-51). Even with the recent passage of national forest policy, and
in light of many other legal protections in Brazil (see Factor D), the
rate of habitat loss throughout southeastern Brazil has increased since
the mid-1990s (CEPF 2001, p. 10; Hodge et al. 1997, p. 1; Rocha et al.
2005, p. 270). The subspecies' population has already been reduced to
such an extent that it is now only known from one possible recent (ca.
2004) sighting of a single bird (Scoss et al. 2006, p. 1), and any
further loss or degradation of remaining suitable habitat could cause
the extinction of this subspecies. Therefore, we find that destruction
and modification of habitat are threats to the continued existence of
the southeastern rufous-vented ground-cuckoo throughout its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The extant population of the southeastern rufous-vented ground-
cuckoo is considered to be extremely small, if it currently exists at
all. Therefore, the removal or dispersal of any individuals of this
subspecies or even a slight decline in the population's fitness due to
any intentional or inadvertent hunting, specimen collection, or other
human disturbances (e.g., birding, hunting, specimen collection,
scientific research) would adversely impact the southeastern rufous-
vented ground-cuckoo's overall viability (see Factor E). However, while
these potential influences remain a concern for future management of
the subspecies, we are not aware of any information currently available
that indicates the use of this subspecies for any commercial,
recreational, scientific, or educational purpose. As a result, we are
not considering overutilization to be a contributing factor to the
continued existence of the southeastern rufous-vented ground-cuckoo.
C. Disease or Predation
Extensive human activity in previously undisturbed or isolated
areas can also result in altered predator populations and the
introduction of various exotic predator species, some of which (e.g.,
feral cats (Felis catus) and rats (Ratus sp.)) can be especially
harmful to populations of endemic bird species (American Bird
Conservancy 2007, p. 1; Courchamp et al. 1999, p. 219; Duncan and
Blackburn 2007, pp. 149-150; Salo et al. 2007, pp. 1241-1242; Small
2005, p. 257). Although large, stable populations of wildlife species
have adapted to natural levels of disease and predation within their
historic ranges, the extant population of the southeastern rufous-
vented ground-cuckoo is considered to be extremely small, if it
currently exists at all. In addition, extensive human activity in
previously undisturbed or isolated areas can lead to the introduction
and spread of exotic diseases, some of which (e.g., West Nile virus)
can negatively impact endemic bird populations (Neotropical
[[Page 40679]]
News 2003, p. 1; Naugle et al. 2004, p. 704).
Any additive mortality to the southeastern rufous-vented ground-
cuckoo population or a decrease in its fitness due to an increase in
the incidence of disease or predation would adversely impact the
subspecies' overall viability (see Factor E). However, while these
potential influences remain a concern for future management of the
subspecies, we are not aware of any information currently available
that indicates the occurrence of disease in the southeastern rufous-
vented ground-cuckoo, or that documents any predation incurred by the
subspecies. As a result, we are not considering disease or predation to
be a contributing factor to the continued existence of the southeastern
rufous-vented ground-cuckoo.
D. The Inadequacy of Existing Regulatory Mechanisms
The southeastern rufous-vented ground-cuckoo is formally recognized
as ``endangered'' in Brazil (Order No. 1.522) and is directly protected
by various laws promulgated by the Brazilian government (ICBP 1981, p.
1; ECOLEX 2007, pp. 1-2). For example, there are measures that
prohibit, or regulate through Federal agency oversight, the following
activities with regard to endangered species: export and international
trade (e.g., Decree No. 76.623, Order No. 419-P), hunting (e.g., Act
No. 5.197), collection and research (Order No. 332), captive
propagation (Order No. 5), and general harm (e.g., Decree No. 3.179).
In addition, there are a wide range of regulatory mechanisms in Brazil
that indirectly protect the southeastern rufous-vented ground-cuckoo
through measures that protect its remaining suitable habitat (ECOLEX
2007, pp. 2-5). For example, there are measures that: (1) Prohibit
exploitation of the remaining primary forests within the Atlantic
Forest biome (e.g., Decree No. 750, Resolution No. 10); (2) govern
various practices associated with the management of primary and
secondary forests, such as logging, charcoal production, reforestation,
recreation, and water resources (e.g., Resolution No. 9, Act No. 4.771,
Decree No. 1.282, Decree No. 3.420, Order No. 74-N, Act No. 7.803); (3)
establish provisions for controlling forest fires (e.g., Decree No.
97.635, Order No. 231-P, Order No. 292-P, Decree No. 2.661); and (4)
regulate industrial developments, such as hydroelectric plants and
biodiesel production (e.g., Normative Instruction No. 65, Law No.
11.116). Finally, there are various measures (e.g., Law No. 11.516, Act
No. 7.735, Decree No. 78, Order No. 1, Act No. 6.938) that direct
Federal and state agencies to promote the protection of lands and
natural resources under their jurisdictions (ECOLEX 2007, pp. 5-6).
Various regulatory mechanisms in Brazil govern the formal
establishment and management of protected areas to promote conservation
of the country's natural resources (ECOLEX 2007, pp. 6-7). These
mechanisms generally aim to protect endangered wildlife and plant
species, genetic resources, overall biodiversity, and native ecosystems
on Federal, state, and privately owned lands (e.g., Law No. 9.985, Law
No. 11.132, Resolution No. 4, Decree No. 1.922). Brazil's formally
established protection areas are categorized based on their overall
management objectives (e.g., National Parks versus Biological
Reserves), and based on those categories they allow varying uses and
provide varying levels of protection for specific resources (Costa
2007, pp. 5-19).
Two of these protected areas, Sooretama Biological Reserve and Doce
River State Park, represent the major sites where the southeastern
rufous-vented ground-cuckoo may still occur (Payne 2005, p. 207; Scott
and Brooke 1985, pp. 125-126), and the protective measures potentially
implemented at these two areas are considered critical for protecting
any remaining populations of the subspecies. However, not all of the
identified threats for the subspecies (e.g., unregulated tourism,
residential encroachment, resource extraction, grazing, and intentional
burning) are sufficiently addressed at the two protected areas that may
still harbor the southeastern rufous-vented ground-cuckoo (AMDA 2006,
p. 2; Barbosa 2007, p. 1; Bruner et al. 2001, pp. 125-128; Nunes and
Kraas 2000, p. 44). Due to various reasons (e.g., lack of funding,
personnel, or local management commitment), some of Brazil's protected
areas exist without the current capacity to achieve their stated
natural resource objectives (Costa 2007, p. 7; IUCN 1999, p. 23-24;
Neotropical News 1996, pp. 9-10; Neotropical News 1999, p. 9). For
example, the Worldwide Fund for Nature found that 47 of 86 protected
areas are considered to remain below their minimum level of
implementation of Federal requirements, with only 7 considered to be
fully implemented (Neotropical News 1999, p. 9).
In the past, the Brazilian government, through various regulations,
policies, incentives, and subsidies, has actively encouraged settlement
of previously undeveloped lands in southeastern Brazil which helped
facilitate the large-scale conversions that have occurred in the
Atlantic Forest biome (Brannstrom 2000, p. 326; Butler 2007, p. 3;
Conservation International 2007c, p. 1; Pivello 2007, p. 2; Ratter et
al. 1997, pp. 227-228; Saatchi et al. 2001, p. 874). More recently, the
Brazilian government has given greater recognition to the environmental
consequences of such rapid expansion, and has taken steps to better
manage some of the natural resources potentially impacted (Butler 2007,
p. 7; Costa 2007, p. 7; Neotropical News 1997a, p. 10; Neotropical News
1997b, p. 11; Neotropical News 1998b, p. 9; Neotropical News 2003, p.
13; Nunes and Kraas 2000, p. 45). These competing priorities make it
difficult to enforce regulations that protect the habitat of the
southeastern rufous-vented ground-cuckoo.
Summary of Factor D
Although there are various government-sponsored measures that
remain in place in Brazil that continue to facilitate development
projects that could harm the species, there are also a wide variety of
regulatory mechanisms in Brazil that require protection of the
southeastern rufous-vented ground-cuckoo and its habitat throughout the
subspecies' potentially occupied range. The existing regulatory
mechanisms, as currently enforced, do not reduce the threats to the
species (BLI 2003a, p. 4; Conservation International 2007c, p. 1; Costa
2007, p. 7; The Nature Conservancy 2007, p. 2; Neotropical News 1997b,
p. 11; Peixoto and Silva 2007, p. 5; Scott and Brooke 1985, p. 118,
130; Venturini et al. 2005, p. 68). Therefore, when combined with
Factors A and E, we find that the existing regulatory mechanisms are
inadequate to ameliorate the current threats to the southeastern
rufous-vented ground-cuckoo throughout its range.
E. Other Natural or Manmade Factors Affecting the Continued Existence
of the Species
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the southeastern
rufous-vented ground-cuckoo. In basic terms, demographic stochasticity
is defined by chance changes in the population growth rate for the
species (Gilpin and Soul[eacute] 1986, p. 27). Population growth rates
are influenced by individual birth and death rates (Gilpin and
Soul[eacute] 1986, p. 27), immigration and emigration rates, as well as
changes in population sex ratios. Natural variation in survival and
reproductive success of individuals and chance disequilibrium of sex
ratios may
[[Page 40680]]
act in concert to contribute to demographic stochasticity (Gilpin and
Soul[eacute] 1986, p. 27). Genetic stochasticity is caused by changes
in gene frequencies due to genetic drift, and diminished genetic
diversity, and/or effects due to inbreeding (i.e., inbreeding
depression) (Lande 1995, p. 786). Inbreeding can have individual or
population-level consequences either by increasing the phenotypic
expression (the outward appearance or observable structure, function or
behavior of a living organism) of recessive, deleterious alleles or by
reducing the overall fitness of individuals in the population
(Charlesworth and Charlesworth 1987, p. 231; Shaffer 1981, p. 131).
Environmental stochasticity is defined as the susceptibility of small,
isolated populations of wildlife species to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
severe storms, prolonged drought, extreme cold spells, wildfire)
(Dunham et al. 1999, p. 9; Mangel and Tier 1994, p. 612; Young 1994,
pp. 410-412). Each risk will be analyzed specifically for the
southeastern rufous-vented ground-cuckoo.
Small, isolated populations of wildlife species are susceptible to
demographic and genetic problems (Shaffer 1981, pp. 130-134). These
threat factors, which may act in concert, include: natural variation in
survival and reproductive success of individuals, chance disequilibrium
of sex ratios, changes in gene frequencies due to genetic drift,
diminished genetic diversity and associated effects due to inbreeding
(i.e., inbreeding depression), dispersal of just a few individuals, a
few clutch failures, a skewed sex ratio in recruited offspring over
just one or a few years, and chance mortality of just a few
reproductive-age individuals.
The southeastern rufous-vented ground-cuckoo requires large blocks
of undisturbed tropical forest (del Hoyo et al. 1997, pp. 606-607;
Payne 2005, pp. 204-207; Sick 1993, p. 286). In addition, while the
subspecies has likely always been rare throughout its historic range
(ICBP 1981, p. 1), it must have maintained a minimum level of genetic
interchange among its local subpopulations in order for them to have
persisted (Middleton and Nisbet 1997, p. 107; Vil[agrave] et al. 2002,
p. 91; Wang 2004, p. 332). However, the tropical forest habitats
throughout the Doce River valley, where the southeastern rufous-vented
ground-cuckoo was last documented, have been severely fragmented (see
Factor A) and the subspecies' extant population is extremely small and
isolated, if it currently exists at all.
In the absence of more species-specific life history data, a
general approximation of a minimum viable population size is referred
to as the 50/500 rule (Franklin 1980, p. 147), as described under
Factor E for the Brazilian merganser. There are no specific past or
present abundance estimates for the southeastern rufous-vented ground
cuckoo; however, the subspecies is only known from one possible recent
(ca. 2004) sighting of a single bird (Scoss et al. 2006, p. 1), and the
extant population is almost certainly well below both of the thresholds
(Ne = 50 and Ne = 500) for an effective
population size. This means that the subspecies' population likely does
not have enough individuals to avoid risks from inbreeding or the
ability to maintain genetic diversity and adapt to changing conditions
over time. Furthermore, if the subspecies does still exist, continued
loss of suitable habitats (see Factor A) is likely to further
exacerbate fragmentation of any remaining occupied patches. As such, we
currently consider the subspecies to be at risk due to its lack of
near- and long-term genetic viability.
Various past and ongoing human activities and their secondary
influences continue to impact all of the remaining suitable habitats
that may still harbor the southeastern rufous-vented ground cuckoo (see
Factors A and D). We expect that any additional loss or degradation of
habitats that are used by the southeastern rufous-vented ground cuckoo
will have disproportionately greater impacts on the subspecies due to
the population's fragmented state. This is because with each
contraction of an existing subpopulation, the likelihood of interchange
with other subpopulations within patches decreases, while the
likelihood of its complete reproductive isolation increases.
The combined effects of habitat fragmentation (Factor A) and
genetic and demographic stochasticity on a species population are
referred to as patch dynamics. Patch dynamics can have profound effects
on fragmented subpopulations and can potentially reduce a species'
respective effective population by orders of magnitude (Gilpin and
Soul[eacute] 1986, p. 31). For example, an increase in habitat
fragmentation can separate subpopulations to the point where
individuals can no longer disperse and breed among habitat patches,
causing a shift in the demographic characteristics of a population and
a reduction in genetic fitness (Gilpin and Soul[eacute] 1986, p. 31).
Without efforts to maintain buffer areas and reconnect some of the
remaining tracts of suitable habitat near the subspecies' currently
occupied sites, it is doubtful that the individual tracts are currently
large enough to support viable populations of many birds endemic to the
Atlantic Forest, like the southeastern rufous-vented ground cuckoo, and
the eventual loss of any small, isolated populations appears to be
inevitable (Goerck 1997, p. 117; Harris and Pimm 2004, pp. 1609-1610;
IUCN 1999, pp. 23-24; Machado and Da Fonseca 2000, pp. 914, 921-922;
Saatchi et al. 2001, p. 873; Scott and Brooke 1985, p. 118). Del Hoyo
et al. (1997, p. 207) suggests that the rufous-vented ground-cuckoo
would be one of the first species to be extirpated from an area when
their primary forest habitat is isolated, as has occurred to another
Neomorphus geoffroyi subspecies at Barro Colorado in response to
operations of the Panama Canal (del Hoyo et al. 1997, pp. 606-607;
Payne 2005, p. 207). Furthermore, as a species' status continues to
decline, often as a result of deterministic forces such as habitat loss
or overutilization, it will become increasingly vulnerable to a broad
array of other forces. If this trend continues, its ultimate extinction
due to one or more stochastic events becomes more likely.
We expect that the southeastern rufous-vented ground cuckoo's
increased vulnerability to demographic stochasticity and inbreeding
will be operative even in the absence of any human-induced threats or
stochastic environmental events, which only act to further exacerbate
the species' vulnerability to local extirpations and eventual
extinction. Demographic and genetic stochastic forces typically operate
synergistically. Initial effects of one threat factor can later
exacerbate the effects of other threat factors, as well as itself
(Gilpin and Soul[eacute] 1986, pp. 25-26). For example, any further
fragmentation of populations will, by definition, result in the further
removal or dispersal of individuals, which will exacerbate the other
threats. Conversely, lack of a sufficient number of individuals in a
local area or a decline in their individual or collective fitness may
cause a decline in the population size, despite the presence of
suitable habitat patches.
Small, isolated populations of wildlife species, such as the
southeastern rufous-vented ground cuckoo, are also susceptible to
natural levels of environmental variability and related
``catastrophic'' events (e.g., severe storms, prolonged drought,
extreme cold spells, wildfire), which we will refer to as environmental
stochasticity (Dunham et al. 1999, p. 9; Mangel and Tier 1994,
[[Page 40681]]
p. 612; Young 1994, pp. 410-412). A single stochastic environmental
event can severely reduce existing wildlife populations and, if the
affected population is already small or severely fragmented, it is
likely that demographic stochasticity or inbreeding will become
operative, which would place the population in jeopardy (Gilpin and
Soul[eacute] 1986, p. 27; Lande 1995, pp. 787-789).
Summary of Factor E
The small and declining numbers that make up the southeastern
rufous-vented ground cuckoo's population makes it susceptible to
natural environmental variability or chance events. In addition to its
declining numbers, the high level of population fragmentation makes the
subspecies susceptible to genetic and demographic stochasticity.
Therefore, we find that demographic, genetic, and environmental
stochastic events are a threat to the continued existence of the
southeastern rufous-vented ground cuckoo throughout its range.
Status Determination for the Southeastern Rufous-vented Ground-cuckoo
We have carefully assessed the best available scientific and
commercial information regarding the past, present, and potential
future threats faced by the southeastern rufous-vented ground-cuckoo.
The subspecies is currently at risk throughout all of its range due to
ongoing threats of habitat destruction and modification (Factor A), and
its lack of near- and long-term genetic and viability due to threats
associated with demographic, genetic, and environmental stochasticity
(Factor E). Furthermore, we have determined that the existing
regulatory mechanisms (Factor D) are not adequate to ameliorate the
current threats to the southeastern rufous-vented ground-cuckoo.
Section 3 of the Act defines an ``endangered species'' as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a ``threatened species'' as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Based on the threats to the southeastern rufous-vented ground-
cuckoo throughout its entire range, as described above, we determine
that the southeastern rufous-vented ground-cuckoo is in danger of
extinction throughout all of its range. Therefore, on the basis of the
best available scientific and commercial information, we are proposing
to list the southeastern rufous-vented ground-cuckoo as an endangered
species throughout all of its range.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, requirements for Federal
protection, and prohibitions against certain practices. Recognition
through listing results in public awareness, and encourages and results
in conservation actions by Federal and State governments, private
agencies and interest groups, and individuals.
Section 7(a) of the Act, as amended, and as implemented by
regulations at 50 CFR part 402, requires Federal agencies to evaluate
their actions within the United States or on the high seas with respect
to any species that is proposed or listed as endangered or threatened,
and with respect to its critical habitat, if any has been proposed or
designated. However, given that the black-hooded antwren, Brazilian
merganser, cherry-throated tanager, fringe-backed fire-eye, Kaempfer's
tody-tyrant, Margaretta's hermit, and southeastern rufous-vented
ground-cuckoo are not native to the United States, we are not
designating critical habitat in this rule.
Section 8(a) of the Act authorizes the provision of limited
financial assistance for the development and management of programs
that the Secretary of the Interior determines to be necessary or useful
for the conservation of endangered and threatened species in foreign
countries. Sections 8(b) and 8(c) of the Act authorize the Secretary to
encourage conservation programs for foreign endangered and threatened
species and to provide assistance for such programs in the form of
personnel and the training of personnel.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered and
threatened wildlife. As such, these prohibitions would be applicable to
the black-hooded antwren, Brazilian merganser, cherry-throated tanager,
fringe-backed fire-eye, Kaempfer's tody-tyrant, Margaretta's hermit,
and southeastern rufous-vented ground-cuckoo. These prohibitions, under
50 CFR 17.21, in part, make it illegal for any person subject to the
jurisdiction of the United States to ``take'' (take includes harass,
harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or
to attempt to engage in any such conduct) any endangered wildlife
species within the United States or upon the high seas; or to import or
export; deliver, receive, carry, transport, or ship in interstate or
foreign commerce in the course of commercial activity; or to sell or
offer for sale in interstate or foreign commerce any endangered
wildlife species. It is also illegal to possess, sell, deliver, carry,
transport, or ship any such wildlife that has been taken in violation
of the Act. Certain exceptions apply to agents of the Service and State
conservation agencies.
Permits may be issued to carry out otherwise prohibited activities
involving endangered and threatened wildlife species under certain
circumstances. Regulations governing permits are codified at 50 CFR
17.22 for endangered species, and 17.32 for threatened species. With
regard to endangered wildlife, a permit may be issued for the following
purposes: for scientific purposes, to enhance the propagation or
survival of the species, and for incidental take in connection with
otherwise lawful activities.
Peer Review
In accordance with our joint policy with National Marine Fisheries
Service, ``Notice of Interagency Cooperative Policy for Peer Review in
Endangered Species Act Activities,'' published in the Federal Register
on July 1, 1994 (59 FR 34270), we will seek the expert opinions of at
least three appropriate independent specialists regarding this proposed
rule. The purpose of peer review is to ensure that our final
determination is based on scientifically sound data, assumptions, and
analyses. We will send copies of this proposed rule to the peer
reviewers immediately following publication in the Federal Register. We
will invite these peer reviewers to comment during the public comment
period on our specific assumptions and conclusions regarding the
proposal to list the black-hooded antwren, Brazilian merganser, cherry-
throated tanager, fringed-backed fire-eye, Kaempfer's tody-tyrant,
Margaretta's hermit, and the southeastern rufous-vented ground-cuckoo.
We will consider all comments and information we receive during the
comment period on this proposed rule during our preparation of a final
determination. Accordingly, our final decision may differ from this
proposal.
Public Hearings
The Act provides for one or more public hearings on this proposal,
if we receive any requests for hearings. We must receive your request
for a public hearing within 45 days after the date of this Federal
Register publication (see DATES). Such requests must be made in writing
and be addressed to the Chief of the Branch of Listing at the address
[[Page 40682]]
shown in the FOR FURTHER INFORMATION CONTACT section. We will schedule
public hearings on this proposal, if any are requested, and announce
the dates, times, and places of those hearings, as well as how to
obtain reasonable accommodations, in the Federal Register at least 15
days before the first hearing.
Required Determinations
National Environmental Policy Act (NEPA)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.), need not be
prepared in connection with regulations adopted under section 4(a) of
the Act. We published a notice outlining our reasons for this
determination in the Federal Register on October 25, 1983 (48 FR
49244).
Clarity of the Rule
We are required by Executive Orders 12866 and 12988, and by the
Presidential Memorandum of June 1, 1998, to write all rules in plain
language. This means that each rule we publish must:
(a) Be logically organized;
(b) Use the active voice to address readers directly;
(c) Use clear language rather than jargon;
(d) Be divided into short sections and sentences; and
(e) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in the ADDRESSES section. To
better help us revise the rule, your comments should be as specific as
possible. For example, you should tell us the numbers of the sections
or paragraphs that are unclearly written, which sections or sentences
are too long, the sections where you feel lists or tables would be
useful, etc.
References Cited
A complete list of all references cited in this proposed rule is
available on the Internet at http://www.regulations.gov or upon request
from the Branch of Listing, Endangered Species Program, U.S. Fish and
Wildlife Service (see FOR FURTHER INFORMATION CONTACT).
Author(s)
The primary authors of this proposed rule are staff members of the
Division of Scientific Authority, U.S. Fish and Wildlife Service.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, we propose to amend part 17, subchapter B of chapter
I, title 50 of the Code of Federal Regulations, as set forth below:
PART 17--[AMENDED]
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.
2. Amend Sec. 17.11(h) by adding new entries for ``Antwren, Black-
hooded,'' ``Cuckoo, Southeastern Rufous-vented Ground,'' ``Fire-eye,
Fringe-backed,'' ``Hermit, Margaretta's,'' ``Merganser, Brazilian,''
``Tanager, Cherry-throated,'' and ``Tody-tyrant, Kaempfer's'' in
alphabetical order under BIRDS to the List of Endangered and Threatened
Wildlife as follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
-------------------------------------------------------- population where Critical Special
Historic range endangered or Status When listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Birds
* * * * * * *
Antwren, black-hooded............ Formicivora Brazil............. Entire............. E ........... NA NA
erythronotos.
* * * * * * *
Cuckoo, southeastern rufous- Neomorphus geoffroyi Brazil............ Entire............. E ........... NA NA
vented ground. dulcis.
* * * * * * *
Fire-eye, fringed-backed......... Pyriglena atra...... Brazil............. Entire............. E ........... NA NA
* * * * * * *
Hermit, Margaretta's............. Phaethornis malaris Brazil............. Entire............. E ........... NA NA
margarettae.
* * * * * * *
Merganser, Brazilian............. Mergus octosetaceus. Brazil, Argentina, Entire............. E ........... NA NA
Paraguay.
* * * * * * *
Tanager, cherry-throated......... Nemosia rourei...... Brazil............. Entire............. E ........... NA NA
* * * * * * *
Tody-tyrant, Kaempfer's.......... Hemitriccus Brazil............. Entire............. E ........... NA NA
kaempferi.
[[Page 40683]]
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dated: July 15, 2009.
James J. Slack,
Acting Deputy Director, U.S. Fish and Wildlife Service.
[FR Doc. E9-18691 Filed 8-11-09; 8:45 am]
BILLING CODE 4310-55-P