[Federal Register Volume 75, Number 187 (Tuesday, September 28, 2010)]
[Proposed Rules]
[Pages 59804-59863]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-23430]
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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; Determination for the
Gunnison Sage-grouse as a Threatened or Endangered Species; Proposed
Rule
Federal Register / Vol. 75, No. 187 / Tuesday, September 28, 2010 /
Proposed Rules
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[DOCKET NO. FWS-R6-ES-2009-0080]
MO 92210-0-0008
Endangered and Threatened Wildlife and Plants; Determination for
the Gunnison Sage-grouse as a Threatened or Endangered Species
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of the results of a status review.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce our
12-month finding on whether to list the Gunnison sage-grouse
(Centrocercus minimus) as threatened or endangered under the Endangered
Species Act of 1973, as amended (Act). After reviewing the best
available scientific and commercial information, we find that the
species is warranted for listing. Currently, however, listing the
Gunnison sage-grouse is precluded by higher priority actions to amend
the Lists of Endangered and Threatened Wildlife and Plants. Upon
publication of this 12-month finding, we will add the Gunnison sage-
grouse to our candidate species list. We will develop a proposed rule
to list this species as our priorities allow. We will make any
determination on critical habitat during development of the proposed
listing rule.
DATES: The determination announced in this document was made on
September 28, 2010.
ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R6-ES-2009-0080. Supporting
documentation we used in preparing this finding is available for public
inspection, by appointment, during normal business hours at the U.S.
Fish and Wildlife Service, Western Colorado Ecological Services Field
Office, U.S. Fish and Wildlife Service, 764 Horizon Drive, Building B,
Grand Junction, Colorado 81506-3946. Please submit any new information,
materials, comments, or questions concerning this finding to the above
address.
FOR FURTHER INFORMATION CONTACT: Allan Pfister, Western Colorado
Supervisor (see ADDRESSES section); by telephone at (970) 243-2778 ext.
29; or by facsimile at (970) 245-6933. If you use a telecommunications
device for the deaf (TDD), please call the Federal Information Relay
Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(A) of the Act (16 U.S.C. 1531 et seq.) requires
that, for any petition to revise the Federal Lists of Threatened and
Endangered Wildlife and Plants that contains substantial scientific or
commercial information that listing a species may be warranted, we make
a finding within 12 months of the date of receipt of the petition. In
this finding, we determine whether the petitioned action is: (a) Not
warranted, (b) warranted, or (c) warranted, but immediate proposal of a
regulation implementing the petitioned action is precluded by other
pending proposals to determine whether species are threatened or
endangered, and expeditious progress is being made to add or remove
qualified species from the Federal Lists of Endangered and Threatened
Wildlife and Plants. Section 4(b)(3)(C) of the Act requires that we
treat a petition for which the requested action is found to be
warranted but precluded as though resubmitted on the date of such
finding, that is, requiring a subsequent finding to be made within 12
months. We must publish these 12-month findings in the Federal
Register.
Previous Federal Actions
On January 18, 2000, we designated the Gunnison sage-grouse as a
candidate species under the Act, with a listing priority number of 5.
However, Candidate Notices of Review (CNOR) are only published
annually; therefore, the Federal Register notice regarding this
decision was not published until December 28, 2000 (65 FR 82310).
Candidate species are plants and animals for which the Service has
sufficient information on their biological status and threats to
propose them as endangered or threatened under the Act, but for which
the development of a proposed listing regulation is precluded by other
higher priority listing activities. A listing priority of 5 is assigned
to species with high magnitude threats that are non-imminent.
On January 26, 2000, American Lands Alliance, Biodiversity Legal
Foundation, and others petitioned the Service to list the Gunnison
sage-grouse (Webb 2000, pp. 94-95). In 2003, the U.S. District Court
ruled that the species was designated as a candidate by the Service
prior to receipt of the petition, and that the determination that a
species should be on the candidate list is equivalent to a 12-month
finding (American Lands Alliance v. Gale A. Norton, C.A. No. 00-2339,
D. D.C.). Therefore, we did not need to respond to the petition.
In the 2003 CNOR, we elevated the listing priority number for
Gunnison sage-grouse from 5 to 2 (69 FR 24876; May 4, 2004), as the
imminence of the threats had increased. In the subsequent CNOR (70 FR
24870; May 11, 2005), we maintained the listing priority number for
Gunnison sage-grouse as a 2. A listing priority number of 2 is assigned
to species with high magnitude threats that are imminent.
Plaintiffs amended their complaint in May 2004, to allege that the
Service's warranted but precluded finding and decision not to emergency
list the Gunnison sage-grouse were in violation of the Act. The parties
filed a stipulated settlement agreement with the court on November 14,
2005, which included a provision that the Service would make a proposed
listing determination by March 31, 2006. On March 28, 2006, the
plaintiffs agreed to a one-week extension (April 7, 2006) for this
determination.
In April 2005, the Colorado Division of Wildlife (CDOW) applied to
the Service for an Enhancement of Survival Permit for the Gunnison
sage-grouse pursuant to section 10(a)(1)(A) of the Act. The permit
application included a proposed Candidate Conservation Agreement with
Assurances (CCAA) between CDOW and the Service. The standard that a
CCAA must meet is that the ``benefits of the conservation measures
implemented under a CCAA, when combined with those benefits that would
be achieved if it is assumed that conservation measures were also to be
implemented on other necessary properties, would preclude or remove any
need to list the species.'' The CCAA, the permit application, and the
Environmental Assessment were made available for public comment on July
6, 2005 (70 FR 38977). The CCAA and Environmental Assessment were
finalized in October 2006, and the associated permit was issued on
October 23, 2006. Landowners with eligible property in southwestern
Colorado who wish to participate can voluntarily sign up under the CCAA
and associated permit through a Certificate of Inclusion by providing
habitat protection or enhancement measures on their lands. If the
Gunnison sage-grouse is listed under the Act, the permit authorizes
incidental take of Gunnison sage-grouse due to otherwise lawful
activities in accordance with the terms of the CCAA (e.g., crop
cultivation, crop harvesting, livestock grazing, farm equipment
operation, commercial/residential development, etc.), as long as the
participating landowner is performing
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activities identified in the Certificate of Inclusion. Four
Certificates of Inclusion have been issued by the CDOW and Service to
private landowners to date.
On April 11, 2006, the Service determined that listing the Gunnison
sage-grouse as a threatened or endangered species was not warranted and
published the final listing determination in the Federal Register on
April 18, 2006 (71 FR 19954). Consequently, we removed Gunnison sage-
grouse from the candidate species list at the time of the final listing
determination. On November 14, 2006, Plaintiffs (the County of San
Miguel, Colorado; Center for Biological Diversity; WildEarth Guardians;
Public Employees for Environmental Responsibility; National Audubon
Society; The Larch Company; Center for Native Ecosystems; Sinapu;
Sagebrush Sea Campaign; Black Canyon Audubon Society; and Sheep
Mountain Alliance) filed a Complaint for Declaratory and Injunctive
relief, pursuant to the Act, and on October 24, 2007, filed an amended
Complaint for Declaratory and Injunctive relief, alleging that the 12-
month finding on the Gunnison sage-grouse violated the Act. On August
18, 2009, a stipulated settlement agreement and Order was filed with
the court, with a June 30, 2010, date by which the Service shall submit
to the Federal Register a 12-month finding, pursuant to 16 U.S.C. Sec.
1533(b)(3)(B), that listing the Gunnison sage-grouse under the Act is
(a) warranted; (b) not warranted; or (c) warranted but precluded by
higher priority listing actions. We published a notice of intent to
conduct a status review of Gunnison sage-grouse on November 23, 2009
(74 Fr 61100). The Court approved an extension of the June 30, 2010,
deadline for the 12-month finding to September 15, 2010.
Additional Special Status Considerations
The Gunnison sage-grouse has an International Union for
Conservation of Nature (IUCN) Red List Category of ``endangered''
(Birdlife International 2009). NatureServe currently ranks the Gunnison
sage-grouse as G1--Critically Imperiled (Nature Serve 2010, entire).
The Gunnison sage-grouse is on the National Audubon Society's WatchList
2007 Red Category which is ``for species that are declining rapidly or
have very small populations or limited ranges, and face major
conservation threats.''
Biology and Ecology of Gunnison Sage-grouse
Gunnison Sage-grouse Species Description
Sage-grouse are the largest grouse in North America. Sage-grouse
(both greater and Gunnison) are most easily identified by their large
size, dark brown color, distinctive black bellies, long pointed tails,
and association with sagebrush habitats. They are dimorphic in size,
with females being smaller. Both sexes have yellow-green eye combs,
which are less prominent in females. Sage-grouse are known for their
elaborate mating ritual where males congregate on strutting grounds
called leks and ``dance'' to attract a mate. During the breeding
season, males have conspicuous filoplumes (specialized erectile
feathers on the neck), and exhibit yellow-green apteria (fleshy bare
patches of skin) on their breasts (Schroeder et al. 1999, p. 2, 18).
Gunnison sage-grouse are smaller in size, have more white barring in
their tail feathers, and have more filoplumes than greater sage-grouse.
Since Gunnison and greater sage-grouse were only recognized as
separate species in 2000, the vast majority of the research relative to
the biology and management of the two species has been conducted on
greater sage-grouse. Gunnison sage-grouse and greater sage-grouse have
similar life histories and habitat requirements (Young 1994, p. 44). In
this finding, we use information specific to the Gunnison sage-grouse
where available but still apply scientific management principles found
relevant for greater sage-grouse to Gunnison sage-grouse management
needs and strategies, a practice followed by the wildlife agencies that
have responsibility for management of both species and their habitat.
Taxonomy
Gunnison sage-grouse and greater sage-grouse are members of the
Phasianidae family. For many years, sage-grouse were considered a
single species. Gunnison sage-grouse (Centrocercus minimus) were
identified as a distinct species based on morphological (Hupp and Braun
1991, pp. 257-259; Young et al. 2000, pp. 447-448), genetic (Kahn et
al. 1999, pp. 820-821; Oyler-McCance et al. 1999, pp. 1460-1462), and
behavioral (Barber 1991, pp. 6-9; Young 1994; Young et al. 2000, p.
449-451) differences and geographical isolation (Young et al. 2000, pp.
447-451). Based on these differences, the American Ornithologist's
Union (2000, pp. 849-850) accepted the Gunnison sage-grouse as a
distinct species. The current ranges of the two species do not overlap
(Schroeder et al. 2004, p. 369). Due to the several lines of evidence
separating the two species cited above, we determined that the best
available information indicates that the Gunnison sage-grouse is a
valid taxonomic species and a listable entity under the Act.
Life History Characteristics
Gunnison and greater sage-grouse depend on a variety of shrub-
steppe habitats throughout their life cycle and are considered obligate
users of several species of sagebrush (Patterson 1952, p. 42; Braun et
al. 1976, p. 168; Schroeder et al. 1999, pp. 4-5; Connelly et al.
2000a, pp. 970-972; Connelly et al. 2004, p. 4-1, Miller et al. in
press, p. 10). Dietary requirements of the two species are also
similar, being composed of nearly 100 percent sagebrush in the winter,
and forbs and insects as well as sagebrush in the remainder of the year
(Wallestad et al. 1975, p. 21; Schroeder et al. 1999, p. 5; Young et
al. 2000, p. 452). Gunnison and greater sage-grouse do not possess
muscular gizzards and, therefore, lack the ability to grind and digest
seeds (Leach and Hensley 1954, p. 389).
In addition to serving as a primary year-round food source,
sagebrush also provides cover for nests (Connelly et al. 2000a, pp.
970-971). Thus, sage-grouse distribution is strongly correlated with
the distribution of sagebrush habitats (Schroeder et al. 2004, p. 364).
Connelly et al. (2000a, p. 970-972) segregated habitat requirements
into four seasons: (1) breeding (2) summer - late brood-rearing (3)
fall and (4) winter. Depending on habitat availability and proximity,
some seasonal habitats may be indistinguishable. The Gunnison Sage-
grouse Rangewide Steering Committee (GSRSC) (2005, p. 27-31) segregated
habitat requirements into three seasons: (1) breeding (2) summer-late
fall and (3) winter. For purposes of this finding, the seasons
referenced in GSRSC (2005) are used because that publication deals
specifically with Gunnison sage-grouse.
Sage-grouse exhibit strong site fidelity (loyalty to a particular
area) to seasonal habitats, which includes breeding, nesting, brood
rearing, and wintering areas, even when the area is no longer of value
(Connelly et al. 2004, p. 3-1). Adult sage-grouse rarely switch among
these habitats once they have been selected, limiting their
adaptability to changes. Sage-grouse distribution is associated with
sagebrush (Schroeder et al. 2004 p. 364), although sagebrush is more
widely distributed than sage-grouse because sagebrush does not
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always provide suitable habitat due to fragmentation and degradation
(Schroeder et al. 2004, pp. 369, 372). Very little of the extant
sagebrush in North America is undisturbed, with up to 50 to 60 percent
having altered understories (forb and grass vegetative composition
under the sagebrush) or having been lost to direct conversion (Knick et
al. 2003, p. 612 and references therein). Mapping altered and depleted
understories is challenging, particularly in semi-arid regions, so maps
depicting only sagebrush as a dominant cover type are deceptive in
their reflection of habitat quality and, therefore, use by sage-grouse
(Knick et al. 2003, p. 616 and references therein). As such, variations
in the quality of sagebrush habitats for sage-grouse (from either
abiotic or anthropogenic events) are better reflected by sage-grouse
distribution and densities, rather than by broad geographic scale maps
of the distribution of sagebrush.
Sage-grouse exhibit a polygamous mating system where a male mates
with several females. Males perform courtship displays and defend their
leks (Patterson 1952, p. 83). Lek displaying occurs from mid-March
through late May, depending on elevation (Rogers 1964, p. 21; Young et
al. 2000, p. 448). Numerous researchers have observed that a relatively
small number of dominant males account for the majority of copulations
on each lek (Schroeder et al. 1999, p. 8). However, an average of 45.9
percent (range 14.3 to 54.5 percent) of genetically identified males in
a population fathered offspring in a given year (Bush 2009, p. 106).
This more recent work suggests that males and females likely engage in
off-lek copulations. Males do not incubate eggs or assist in chick
rearing.
Lek sites can be located on areas of bare soil, wind-swept ridges,
exposed knolls, low sagebrush, meadows, and other relatively open sites
with good visibility and low vegetation structure (Connelly et al.
1981, pp. 153-154; Gates 1985, pp. 219-221; Klott and Lindzey 1989, pp.
276-277; Connelly et al. 2004, pp. 3-7 and references therein). In
addition, leks are usually located on flat to gently sloping areas of
less than 15 percent grade (Patterson 1952, p. 83; Giezentanner and
Clark 1974, p. 218; Wallestad 1975, p. 17; Autenrieth 1981, p. 13).
Leks are often surrounded by denser shrub-steppe cover, which is used
for escape, and thermal and feeding cover. Leks can be formed
opportunistically at any appropriate site within or adjacent to nesting
habitat (Connelly et al. 2000a, p. 970). Lek habitat availability is
not considered to be a limiting factor for sage-grouse (Schroeder 1997,
p. 939). However, adult male sage-grouse demonstrate strong yearly
fidelity to lek sites (Patterson 1952, p. 91; Dalke 1963 et al., pp.
817-818), and some Gunnison sage-grouse leks have been used since the
1950s (Rogers 1964, pp. 35-40).
The pre-laying period is from late-March to April. Pre-laying
habitats for sage-grouse need to provide a diversity of vegetation
including forbs that are rich in calcium, phosphorous, and protein to
meet the nutritional needs of females during the egg development period
(Barnett and Crawford 1994, p. 117; Connelly et al. 2000a, p. 970).
During the pre-egg laying period, female sage-grouse select forbs that
generally have higher amounts of calcium and crude protein than
sagebrush (Barnett and Crawford 1994, p. 117).
Nesting occurs from mid-April to June. Average earliest nest
initiation was April 30, and the average latest nest initiation was May
19, in the western portion of the Gunnison Basin (Childers 2009, p. 3).
Radio-tracked Gunnison sage-grouse nest an average of 4.3 kilometers
(km ) (2.7 miles (mi)) from the lek nearest to their capture site, with
almost half nesting within 3 km (2 mi) of their capture site (Young
1994, p. 37). Nest sites are selected independent of lek locations, but
the reverse is not true (Bradbury et al. 1989, p. 22; Wakkinen et al.
1992, p. 382). Thus, leks are indicative of nesting habitat. Eighty-
seven percent of all Gunnison sage-grouse nests were located less than
6 km (4 mi) from the lek of capture (Apa 2004, p. 21). While earlier
studies indicated that most greater sage-grouse hens nest within 3 km
(2 mi) of a lek, more recent research indicated that many hens actually
move much further from leks to nest based on nesting habitat quality
(Connelly et al. 2004, p. 4-4). Female greater sage-grouse have been
documented to travel more than 20 km (13 mi) to their nest site after
mating (Connelly et al. 2000a, p. 970). Female Gunnison sage-grouse
exhibit strong fidelity to nesting locations (Young 1994, p. 42; Lyon
2000, p. 20, Connelly et al. 2004, p. 4-5; Holloran and Anderson 2005,
p. 747). The degree of fidelity to a specific nesting area appears to
diminish if the female's first nest attempt in that area was
unsuccessful (Young 1994, p. 42). However, there is no statistical
indication that movement to new nesting areas results in increased
nesting success (Connelly et al. 2004, p. 3-6; Holloran and Anderson
2005, p. 748).
Gunnison sage-grouse typically select nest sites under sagebrush
cover with some forb and grass cover (Young 1994, p. 38), and
successful nests were found in higher shrub density and greater forb
and grass cover than unsuccessful nests (Young 1994, p. 39). The
understory of productive sage-grouse nesting areas contains native
grasses and forbs, with horizontal and vertical structural diversity
that provides an insect prey base, herbaceous forage for pre-laying and
nesting hens, and cover for the hen while she is incubating (Schroeder
et al. 1999, p. 11; Connelly et al. 2000a, p. 971; Connelly et al.
2004, pp. 4-5-4-8). Shrub canopy and grass cover provide concealment
for sage-grouse nests and young, and are critical for reproductive
success (Barnett and Crawford 1994, pp. 116-117; Gregg et al. 1994, pp.
164-165; DeLong et al. 1995, pp. 90-91; Connelly et al. 2004, p. 4-4).
Few herbaceous plants are growing in April when nesting begins, so
residual herbaceous cover from the previous growing season is critical
for nest concealment in most areas (Connelly et al. 2000a, p. 977).
Nesting success for Gunnison sage-grouse is highest in areas where
forb and grass covers are found below a sagebrush canopy cover of 15 to
30 percent (Young et al. 2000, p. 451). These numbers are comparable to
those reported for the greater sage-grouse (Connelly et al. 2000a, p.
971). Nest success for greater sage-grouse is greatest where grass
cover is present (Connelly et al. 2000a, p. 971). Because of the
similarities between these two species, we believe that increased nest
success in areas of forb and grass cover below the appropriate
sagebrush canopy cover is likely the case for Gunnison sage-grouse as
well.
Mean clutch size for Gunnison sage-grouse is 6.8 0.7
eggs (Young 1994, p. 37). The mean clutch size for Gunnison sage-grouse
in the Gunnison Basin was 6.3, with 94 percent of eggs in successful
nests hatching (Childers 2009, p. 3). Despite average clutch sizes of 7
eggs (Connelly et al. in press, p. 15), little evidence exists that
populations of sage-grouse produce large annual surpluses (Connelly et
al. in press, p. 15, 24). The inability of sage-grouse to produce large
annual surpluses limits their ability to respond under favorable
environmental conditions to make up for population declines. Re-nesting
rates following the loss of the original nest appear very low in
Gunnison sage-grouse, with one study reporting re-nesting rates of 4.8
percent (Young 1994, p. 37). Only one instance of re-nesting was
observed over a 5-year period during which a total of 91 nesting
Gunnison sage-grouse hens were monitored (Childers 2009, p. 3).
Most sage-grouse eggs hatch in June, with a peak between June 10
and June
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20 (GSRSC, 2005, p. 24). Chicks are precocial (mobile upon hatching)
and leave the nest with the hen shortly after hatching. Forbs and
insects are essential nutritional components for sage-grouse chicks
(Klebenow and Gray 1968, pp. 81-83; Peterson 1970, pp. 149-151; Johnson
and Boyce 1991, p. 90; Connelly et al. 2004, p. 3-3). Therefore, early
brood-rearing habitat for females with chicks must provide adequate
cover adjacent to areas rich in forbs and insects to assure chick
survival during this period (Connelly et al. 2000, p. 971; Connelly et
al. 2004, p. 4-11). Gunnison sage-grouse chick dietary requirements of
insects and forbs also are expected to be similar to greater sage-
grouse and other grouse species (Apa 2005, pers. comm.).
The availability of food and cover are key factors that affect
chick and juvenile survival. During the first 3 weeks after hatching,
insects are the primary food of chicks (Patterson 1952, p. 201;
Klebenow and Gray 1968, p. 81; Peterson 1970, pp. 150-151; Johnson and
Boyce 1990, pp. 90-91; Johnson and Boyce 1991, p. 92; Drut et al.
1994b, p. 93; Pyle and Crawford 1996, p. 320; Fischer et al. 1996a, p.
194). Diets of 4- to 8-week-old greater sage-grouse chicks were found
to have more plant material as the chicks matured (Peterson 1970, p.
151). Succulent forbs are predominant in the diet until chicks exceed 3
months of age, at which time sagebrush becomes a major dietary
component (Klebenow 1969, pp. 665-656; Connelly and Markham 1983, pp.
171-173; Fischer et al. 1996b, p. 871; Schroeder et al. 1999, p. 5).
Early brood-rearing habitat is found close to nest sites (Connelly
et al. 2000a, p. 971), although individual females with broods may move
large distances (Connelly 1982, as cited in Connelly et al. 2000a, p.
971). Young (1994, pp. 41-42) found that Gunnison sage-grouse with
broods used areas with lower slopes than nesting areas, high grass and
forb cover, and relatively low sagebrush cover and density. Broods
frequently used the edges of hay meadows, but were often flushed from
areas found in interfaces of wet meadows and habitats providing more
cover, such as sagebrush or willow-alder (Salix-Alnus).
By late summer and into the early fall, individuals become more
social, and flocks are more concentrated (Patterson 1952, p. 187).
Intermixing of broods and flocks of adult birds is common, and the
birds move from riparian areas to sagebrush-dominated landscapes that
continue to provide green forbs. During this period, Gunnison sage-
grouse can be observed in atypical habitat such as agricultural fields
(Commons 1997, pp. 79-81). However, broods in the Gunnison Basin
typically do not use hay meadows further away than 50 meters (m) (165
feet (ft)) of the edge of sagebrush stands (Colorado Sage Grouse
Working Group (CSGWG) 1997, p. 13).
As fall approaches, sage-grouse move from riparian to upland areas
and start to shift to a winter diet (GSRSC 2005, p. 25). Movements to
winter ranges are slow and meandering (Connelly et al. 1988, p. 119).
The extent of movement varies with severity of winter weather,
topography, and vegetation cover. Sage-grouse may travel short
distances or many miles between seasonal ranges. In response to severe
winters, Gunnison sage-grouse move as far as 27 km (17 mi) (Root 2002,
p. 14). Flock size in winter is variable (15 to 100+), and flocks
frequently consist of a single sex (Beck 1977, p. 21).
From late autumn through early spring, greater and Gunnison sage-
grouse diet is almost exclusively sagebrush (Rasmussen and Griner 1938,
p. 855; Batterson and Morse 1948, p. 20; Patterson 1952, pp. 197-198;
Wallestad et al. 1975, pp. 628-629; Young et al. 2000, p. 452). Many
species of sagebrush can be consumed (Remington and Braun 1985, pp.
1056-1057; Welch et al. 1988, p. 276, 1991; Myers 1992, p. 55).
Characteristics of sage-grouse winter habitats are also similar through
the range of both species (Connelly et al. 2000a, p. 972). In winter,
Gunnison sage-grouse are restricted to areas of 15 to 30 percent
sagebrush cover, similar to the greater sage-grouse (Connelly et al.
2000a, p. 972; Young et al. 2000, p. 451). However, they may also use
areas with more deciduous shrubs during the winter (Young et al. 2000,
p. 451).
Sagebrush stand selection in winter is influenced by snow depth
(Patterson 1952, pp. 188-189; Connelly 1982 as cited in Connelly et al.
2000a, p. 980) and in some areas, topography (Beck 1977, p. 22;
Crawford et al. 2004, p. 5). Winter areas are typically characterized
by canopy cover greater than 25 percent and sagebrush greater than 30
to 41 cm (12 to 16 in) tall (Shoenberg 1982, p. 40) associated with
drainages, ridges, or southwest aspects with slopes less than 15
percent (Beck 1977, p. 22). Lower flat areas and shorter sagebrush
along ridge tops provide roosting areas. In extreme winter conditions,
greater sage-grouse will spend nights and portions of the day burrowed
into ``snow burrows'' (Back et al. 1987, p. 488).
Hupp and Braun (1989, p. 825) found that most Gunnison sage-grouse
feeding activity in the winter occurred in drainages and on slopes with
south or west aspects in the Gunnison Basin. During a severe winter in
the Gunnison Basin in 1984, less than 10 percent of the sagebrush was
exposed above the snow and available to sage-grouse (Hupp, 1987, pp.
45-46). In these conditions, the tall and vigorous sagebrush typical in
drainages was an especially important food source.
Sage-grouse typically live between 3 and 6 years, but individuals
up to 9 years of age have been recorded in the wild (Connelly et al.
2004, p. 3-12). Adult female Gunnison sage-grouse apparent survival
rates from April through September averaged 57 percent, and adult male
survival averaged 45 percent (Childers 2009, p. 2). From October
through March, adult female Gunnison sage-grouse apparent survival
rates averaged 79 percent, and adult male survival averaged 96 percent
(Childers 2009, p.2). In one study, Gunnison sage-grouse survival from
April 2002 through March 2003 was 48 ( 7) percent for males
and 57 ( 7) percent for females (Apa 2004, p. 22).
Preliminary results from the Gunnison and San Miguel populations
indicate potential important temporal and spatial variation in
demographic parameters, with apparent annual adult survival rates
ranging from approximately 65 to 80 percent (CDOW 2009a, p. 8).
Gunnison sage-grouse female survival in small isolated populations was
52 ( 8) percent, compared to 71 ( 11) percent
survival in the Gunnison Basin, the only population with greater than
500 individuals (Apa 2004, p. 22). Higher adult survival has been
observed in a lower elevation and warmer area (Dry Creek Basin of the
San Miguel population - 90 percent) than in a higher elevation and
colder, snowier, area (Miramonte portion of the San Miguel population -
65 percent) (CDOW 2009a, p.8). Other factors affecting survival rates
include climatic differences between years and age (Zablan 1993, pp. 5-
6).
Apparent chick survival from hatch to the beginning of fall (30
September) averaged 7 percent over a 5-year period in the western
portion of the Gunnison Basin (Childers 2009, pp. 4-6). Apparent chick
survival to 90 days of age has ranged from approximately 15 to 30
percent in the Gunnison Basin, with no juvenile recruitment observed
over several years in the San Miguel population (CDOW 2009a, p. 8).
Based on a review of many field studies, juvenile survival rates range
from 7 to 60 percent (Connelly et al. 2004, p. 3-12). The variation in
juvenile survival rates may be associated with sex, weather, harvest
rates (no harvesting of Gunnison sage-grouse is currently permitted),
age of brood female (broods with adult females have higher
[[Page 59808]]
survival), and with habitat quality (rates decrease in poor habitats)
(Schroeder et al. 1999, p. 14; Connelly et al., in press, p. 20).
Greater sage-grouse require large, interconnected expanses of
sagebrush with healthy, native understories (Patterson 1952, p. 9;
Knick et al. 2003, p. 623; Connelly et al. 2004, pp. 4-15; Connelly et
al. in press, p. 10; Pyke in press, p. 7; Wisdom et al. in press, p.
4). However, little information is available regarding minimum
sagebrush patch sizes required to support populations of greater or
Gunnison sage-grouse. Gunnison sage-grouse have not been observed to
undertake the large seasonal and annual movements observed in greater
sage-grouse. However, movements of up to 24 km (15 mi) have been
observed in individual Gunnison sage-grouse in the Gunnison Basin
population only (Phillips 2010, pers. comm.).
Sage-grouse typically occupy large expanses of sagebrush-dominated
habitats composed of a diversity of sagebrush species and subspecies.
Use of other habitats intermixed with sagebrush, such as riparian
meadows, agricultural lands, steppe dominated by native grasses and
forbs, scrub willow (Salix spp.), and sagebrush habitats with some
conifer or quaking aspen (Populus tremuloides), is not uncommon
(Connelly et al 2004, p. 4-18 and references therein). Sage-grouse have
been observed using human-altered habitats throughout their range.
However, the use of non-sagebrush habitats by sage-grouse is
dependent on the presence of sagebrush habitats in close proximity
(Connelly et a.lal 2004, p. 4-18 and references therein).
Historic Range and Distribution of Gunnison Sage-grouse
Based on historical records, museum specimens, and potential
habitat distribution, Gunnison sage-grouse historically occurred in
southwestern Colorado, northwestern New Mexico, northeastern Arizona,
and southeastern Utah (Schroeder et al. 2004, pp. 370-371). Accounts of
Gunnison sage-grouse in Kansas and Oklahoma, as suggested by Young et
al. (2000, pp. 446-447), are not supported with museum specimens, and
Schroeder et al. (2004, p. 371) found inconsistencies with the
historical records and the sagebrush habitat currently available in
those areas. Applegate (2001, p. 241) found that none of the sagebrush
species closely associated with sage-grouse occurred in Kansas. He
attributed historical, anecdotal reports as mistaken locations or
misidentification of lesser prairie chickens. For these reasons,
southwestern Kansas and western Oklahoma are not considered within the
historic range of Gunnison sage-grouse (Schroeder et al. 2004, p. 371).
The GSRSC (2005) modified the historic range from Schroeder et al.
(2004), based on more complete information on historic and current
habitat and the distribution of the species (GSRSC 2005, pp. 34-35).
Based on this information, the maximum Gunnison sage-grouse historical
(presettlement) range is estimated to have been 55,350 square
kilometers (km\2\) (21,370 square miles (mi\2\)) (GSRSC 2005, p. 32).
To be clear, only a portion of the historical range would have been
occupied at any one time, while all of the current range is considered
occupied. Also, we do not know what portion of the historical range was
simultaneously occupied, or what the total population was.
Much of what was once Gunnison sage-grouse sagebrush habitat was
already lost prior to 1958. A qualitative decrease in sagebrush was
attributed to overgrazing from the 1870s until about 1934 (Rogers 1964,
p. 13). Additional adverse effects occurred as a result of newer range
management techniques implemented to support livestock by the Bureau of
Land Management (BLM), Soil Conservation Service, and U.S. Forest
Service (USFS) (Rogers 1964, p. 13). In the 1950s, large areas of
sagebrush within the range of Gunnison sage-grouse were eradicated by
herbicide spraying or burning (Rogers 1964, pp. 12-13, 22-23, 26).
About 155,673 hectares (ha) (384,676 ac) of sagebrush habitat was
lost from 1958 to 1993 within southwestern Colorado (Oyler-McCance et
al. 2001, p. 327). Sagebrush loss was lower in the Gunnison Basin (11
percent) compared to all other areas in southwestern Colorado (28
percent) (Oyler-McCance et al. 2001, p. 328). Considerable
fragmentation of sagebrush vegetation was also quantitatively
documented during that same time period (Oyler-McCance et al. 2001, p.
329). Sage-grouse habitat in southwestern Colorado (the majority of the
range of Gunnison sage-grouse) has been more severely impacted than
sagebrush habitat elsewhere in Colorado.
The Colorado River Storage Project (CRSP) resulted in construction
of three reservoirs within the Gunnison Basin in the mid-late 1960s
(Blue Mesa and Morrow) and mid-1970s (Crystal). Several projects
associated with CRSP were constructed in this same general timeframe to
provide additional water storage and resulted in the loss of an
unquantified, but likely small, amount of sagebrush habitat. These
projects provide water storage and, to a certain extent, facilitate
agricultural activities that maintain the fragmentation and habitat
lost historically throughout the range of Gunnison sage-grouse.
In summary, a substantial amount of sagebrush habitat within the
range of the Gunnison sage-grouse had been lost prior to 1960. The
majority of the remaining habitat is highly fragmented, although to a
lesser extent in the Gunnison Basin than in the remainder of the
species habitat.
Current Distribution and Population Estimates
The historic and current geographic ranges of Gunnison's and
greater sage-grouse were quantitatively analyzed to determine the
species' response to habitat loss and detrimental land uses (Wisdom et
al., in press, 2009, entire). A broad spectrum of biotic, abiotic, and
anthropogenic conditions were found to be significantly different
between extirpated and occupied ranges (Wisdom et al., in press, 2009,
p. 1.). Sagebrush area is one of the best landscape predictors of sage-
grouse persistence (Wisdom et al., in press, 2009, p. 17 and references
therein). Because of the loss and fragmentation of habitat within its
range, no expansive, contiguous areas that could be considered
strongholds (areas of occupied range where the risk of extirpation
appears low) are evident for Gunnison sage-grouse (Wisdom et al., in
press, 2009, p. 24). We do not know the minimum amount of sagebrush
habitat needed by Gunnison sage-grouse to ensure long-term persistence.
However, based on Wisdom et al., in press, we do know that landscapes
containing large and contiguous sagebrush patches and sagebrush patches
in close proximity increase the likelihood of sage-grouse persistence.
Gunnison sage-grouse currently occur in seven widely scattered and
isolated populations in Colorado and Utah, occu2pying 3,795 km\2\
(1,511mi\2\) (GSRSC 2005, pp. 36-37; CDOW 2009b, p. 1). The seven
populations are Gunnison Basin, San Miguel Basin, Monticello-Dove
Creek, Pinon Mesa, Crawford, Cerro Summit-Cimarron-Sims Mesa, and
Poncha Pass (Figure 1). A comparative summary of the land ownership and
recent population estimates among these seven populations is presented
in Table 1 and Table 2, respectively. Population trends over the last
nine years indicate that six of the populations are in decline. The
Gunnison Basin population, while showing variation over the years, has
been relatively stable through the period (CDOW 2009a p. 2). Six of the
[[Page 59809]]
populations are very small and fragmented (all with less than 40,500 ha
(100,000 acres) of habitat likely used by grouse and less than 50 males
counted on leks) (CDOW 2009a, p. 5). The San Miguel population, the
second largest, comprises six fragmented subpopulations.
Figure 1. Locations of Current Gunnison Sage-grouse Populations.
[GRAPHIC] [TIFF OMITTED] TP28SE10.000
Table 1. Percent surface ownership of total Gunnison sage-grouse occupied\a\ habitat (from GSRSC\b\ 2005, pp. D-3-D-6; CDOW\c\ 2009b, p. 1)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gunnison Sage-grouse Occupied Habitat Management and Ownership
-----------------------------------------------------------------------------------------------------------------------------------------------
Population hectares acres BLM\d\ NPS\e\ USFS\f\ CDOW CO State State of Private
----------------------------------------------------------------------------------------------------------------- Land UT ----------
Board ----------
% % % % ---------- %
% %
-----------------------------------------------------------------------------------------------------------------------------------------------
Gunnison Basin 239,953 592,936 51 2 14 3 <1 0 29
--------------------------------------------------------------------------------------------------------------------------------------------------------
San Miguel Basin 41,022 101,368 36\g\ 0 1 11 3\g\ 0 49\g\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello-Dove Creek (Combined) 45,275 111,877 7 0 0 3 0 <1 90
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dove Creek 16,706 41,282 11 0 0 8 0 0 81
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello 28,569 70,595 4 0 0 0 0 1 95
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pi[ntilde]on Mesa 15,744 38,904 28 0 2 19 0 0 51
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cerro Summit-Cimarron-Sims Mesa 15,039 37,161 13 <1 0 11 0 0 76
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crawford 14,170 35,015 63 12 0 2 0 0 23
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 59810]]
Poncha Pass 8,262 20,415 48 0 26 0 2 0 23
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rangewide 379,464 937,676 42 2 10 5 <1 <1 41
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\Occupied Gunnison sage-grouse habitat is defined as areas of suitable habitat known to be used by Gunnison sage-grouse within the last 10 years from
the date of mapping, and areas of suitable habitat contiguous with areas of known use, which have no barriers to grouse movement from known use areas
(GSRSC 2005, p. 54).
\b\Gunnison Sage-grouse Rangewide Steering Committee
\c\Colorado Division of Wildlife
\d\Bureau of Land Management
\e\National Park Service
\f\United States Forest Service
\g\Estimates reported in San Miguel Basin Gunnison Sage-grouse Conservation Plan (2009 p. 28) vary by up to 2 percent in these categories from those
reported here. We consider these differences insignificant.
Table 2. Gunnison Sage-grouse population estimates by year derived from the formula presented in the Gunnison sage-grouse Rangewide Conservation Plan
(GSRSC\a\ 2005, pp. 44-45) applied to high male counts on leks (CDOW\b\ 2009a, p. 2).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated Population
-----------------------------------------------------------------------------------------------------------------
Year
-----------------------------------------------------------------------------------------------------------------
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gunnison Basin 3,493 3,027 2,453 2,443 4,700 5,205 4,616 3,669 3,817 3,655
--------------------------------------------------------------------------------------------------------------------------------------------------------
San Miguel Basin 392 383 250 255 334 378 324 216 162 123
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello-Dove Creek (Combined) 363 270 186 162 196 191 245 245 191 n/a\c\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello 231 172 147 152 162 118 216 216 182 n/a\c\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dove Creek 132 98 39 10 34 74 29 29 10 44
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pi[ntilde]on Mesa 152 132 123 142 167 152 123 108 78 74
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cerro Summit-Cimarron-Sims Mesa 59 39 29 39 25 49 34 10 39 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crawford 137 206 118 128 191 201 113 103 78 20
--------------------------------------------------------------------------------------------------------------------------------------------------------
Poncha Pass 25 44 34 39 44 44 25 25 20 15
--------------------------------------------------------------------------------------------------------------------------------------------------------
Totals 4,621 4,101 3,194 3,208 5,656 6,220 5,480 4,376 4,386 n/a\c\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\Gunnison Sage-grouse Rangewide Steering Committee
\b\Colorado Division of Wildlife
\c\2010 lek count data for the Monticello group was not available at the time of publication
Gunnison Basin Population - The Gunnison Basin is an intermontane
basin that includes parts of Gunnison and Saguache Counties, Colorado.
The current Gunnison Basin population is distributed across
approximately 240,000 ha (593,000 ac), roughly centered on the town of
Gunnison. Elevations in the area range from 2,300 to 2,900 m (7,500 to
9,500 ft). Approximately 70 percent of the land area is managed by
Federal agencies (67 percent) and CDOW (3 percent), and the remaining
30 percent comprises primarily private lands. Big sagebrush (Artemesia
tridentata) dominates the upland vegetation and has a highly variable
growth form depending on local site conditions. In 2009, 83 leks were
surveyed for breeding activity in the Gunnison Basin, and 42 of these
leks were active (at least two males in attendance during at least two
of four 10-day count periods), 6 inactive
[[Page 59811]]
(inactive for at least 5 consecutive years), 9 historic (inactive for
at least 10 consecutive years), and 26 were of unknown status
(variability in counts resulted in lek not meeting requirements for
active, inactive, or historic) (CDOW 2009d, pp. 28-30). Approximately
45 percent of leks in the Gunnison Basin occur on private land and 55
percent on public land, primarily BLM (GSRSC 2005, p. 75). The 2010
population estimate for the Gunnison Basin was 3,655 (CDOW 2010a, p.
2). Rogers (1964, p. 20) stated that Gunnison County was one of five
counties containing the majority of sage-grouse in Colorado in 1961.
The vast majority (87 percent) of Gunnison sage-grouse are now found
only in the Gunnison Basin population.
San Miguel Basin Population - The San Miguel Basin population is in
Montrose and San Miguel Counties in Colorado, and is composed of six
small subpopulations using different areas--(Dry Creek Basin, Hamilton
Mesa, Miramonte Reservoir, Gurley Reservoir, Beaver Mesa, and Iron
Springs) occupying a total of approximately 41,000 ha (101,000 ac).
Some of these six areas are used year-round by sage-grouse, and others
are used seasonally. The overall acreage figure for this population is
heavily skewed by the large percentage (approximately 62 percent) of
land in the Dry Creek Basin (San Miguel Basin Gunnison Sage-grouse
Working Group 2009, p. 28). The Dry Creek Basin area contains some of
the poorest habitat and smallest grouse populations in the San Miguel
population (San Miguel Basin Gunnison sage-grouse Conservation Plan
2009, pp. 28, 36). Gunnison sage-grouse in the San Miguel Basin move
widely between these areas (Apa 2004, p. 29; Stiver and Gibson 2005, p.
12). The area encompassed by this population is believed to have once
served as critical migration corridors between populations to the north
(Cerro Summit-Cimarron-Sims Mesa) and to the south (Monticello-Dove
Creek) (San Miguel Basin Gunnison Sage-grouse Working Group 2009, p.
9).
Sagebrush habitat in the Dry Creek Basin area is patchily
distributed, and the understory is either lacking in grass and forb
diversity or nonexistent. Where irrigation is possible, private lands
in the southeast portion of Dry Creek Basin are cultivated. Sagebrush
habitat on private land has been heavily thinned or removed entirely
(GSRSC 2005, p. 96). Gunnison sage-grouse use the Hamilton Mesa area
(1,940 ha (4,800 ac)) in the summer, but use of Hamilton Mesa during
other seasons is unknown. Gunnison sage-grouse occupy approximately
4,700 ha (11,600 ac) around Miramonte Reservoir (GSRSC 2005, p. 96).
Sagebrush stands there are generally contiguous with a mixed grass and
forb understory. Occupied habitat at the Gurley Reservoir area (3,305
ha (7,500 ac)) is heavily fragmented by urban development, and the
understory is a mixed grass and forb community. Farming attempts in the
early 20th century led to the removal of much of the sagebrush,
although agricultural activities are now restricted primarily to the
seasonally irrigated crops (hay meadows), and sagebrush has
reestablished in most of the failed pastures. However, grazing pressure
and competition from introduced grasses have kept the overall sagebrush
representation low (GSRSC 2005, pp. 96-97). Sagebrush stands in the
Iron Springs and Beaver Mesa areas (2,590 ha and 3,560 ha (6,400 ac and
8,800 ac respectively)) are contiguous with a mixed grass understory.
The Beaver Mesa area has numerous scattered patches of oakbrush
(Quercus gambelii). Rogers (1964, p. 9) reported that all big
sagebrush-dominated habitats in San Miguel and Montrose Counties were
historically used by Gunnison sage-grouse.
The 2010 population estimate for the entire San Miguel Basin was
123 individuals on nine leks (CDOW 20010, p. 3). With the exception of
2007, CDOW has been translocating Gunnison sage-grouse from the
Gunnison Basin to Dry Creek Basin on a yearly basis since the spring of
2006 (CDOW 2009a, p. 133). In the spring of 2006, six individuals were
released near the Desert Lek. An additional two individuals were
released in the fall. Nine individuals were translocated in the spring
of 2008. An additional 30 individuals were translocated in the fall of
2009. A 40 to 50 percent mortality rate has been observed within the
first year after release, compared to an average annual mortality rate
of approximately 20 percent for radiomarked adult sage-grouse (CDOWa
2009, p. 9).
Monticello-Dove Creek Population - This population is divided into
two disjunct subpopulations of Gunnison sage-grouse. Currently, the
largest group is near the town of Monticello, in San Juan County, Utah.
Gunnison sage-grouse in this subpopulation inhabit a broad plateau on
the northeast side of the Abajo Mountains, with fragmented patches of
sagebrush interspersed with large grass pastures and agricultural
fields. The Utah Division of Wildlife Resources (UDWR) estimated
population numbers between 583 and 1,050 individuals in 1972 and
between 178 and 308 individuals in 2002 (UDWR 2009, 29.21 p. 1). The
UDWR estimates that Gunnison sage-grouse currently occupy about 24,000
ha (60,000 ac) in the Monticello area. The 2009 population estimate for
Monticello was 182 individuals with three active and one inactive leks
(UDWR 2009, p. 5).
The Dove Creek subpoulation is located primarily in western Dolores
County, Colorado, north and west of Dove Creek, although a small
portion of occupied habitat extends north into San Miguel County.
Habitat north of Dove Creek is characterized as mountain shrub habitat,
dominated by oakbrush interspersed with sagebrush. The area west of
Dove Creek is dominated by sagebrush, but the habitat is highly
fragmented. Lek counts in the Dove Creek area were over 50 males in
1999, suggesting a population of about 245 birds, but declined to 2
males in 2009 (CDOW 2009a, p. 71), suggesting a population of 10 birds.
A new lek was found in 2010, and the 2010 population estimate was 44
individuals on 2 leks (CDOW 2010, p. 1). Low sagebrush canopy cover, as
well as low grass height, exacerbated by drought, may have led to nest
failure and subsequent population declines (Connelly et al. 2000a, p.
974; Apa 2004, p. 30). Rogers (1964, p. 9) reported that all sagebrush-
dominated habitats in Dolores and Montezuma Counties within Gunnison
sage-grouse range in Colorado were historically used by Gunnison sage-
grouse.
Pinon Mesa Population - The Pinon Mesa population occurs on the
northwest end of the Uncompahgre Plateau in Mesa County, about 35 km
(22 mi) southwest of Grand Junction, Colorado. The 2010 population
estimate for Pinon Mesa was 74 (CDOW 2010, p. 2). Of the ten known
leks, only four were active in 2009 (CDOW, 2009a, p. 3). The Pinon Mesa
area may have additional leks, but the high percentage of private land,
a lack of roads, and heavy snow cover during spring make locating
additional leks difficult. Gunnison sage-grouse likely occurred
historically in all suitable sagebrush habitat in the Pinon Mesa area,
including the Dominguez Canyon area of the Uncompaghre Plateau,
southeast of Pinon Mesa proper (Rogers 1964, p. 114). Their current
distribution has been substantially reduced from historic levels to
15,744 ha (38,904 ac) (GSRSC 2005, p. 87).
Crawford Population - The Crawford population of Gunnison sage-
grouse is in Montrose County, Colorado, about 13 km (8 mi) southwest of
the town of Crawford and north of the Gunnison River. Basin big
sagebrush (Artemisia tridentata tridentata) and black
[[Page 59812]]
sagebrush (A. nova) dominate the mid-elevation uplands (GSRSC 2005, p.
62). The 2010 population estimate for Crawford was 20 individuals (CDOW
2010, p. 1) in 14,170 ha (35,015 ac) of occupied habitat. Four active
leks are currently in the Crawford population on BLM lands in sagebrush
habitat adjacent to an 11-km (7-mi) stretch of road. This area
represents the largest contiguous sagebrush-dominated habitat within
the Crawford boundary (GSRSC 2005, p. 64).
Cerro Summit-Cimarron-Sims Mesa Population - This population is
divided into two geographically separated subpopulations, both in
Montrose County, Colorado. The Cerro Summit-Cimarron subpopulation is
centered about 24 km (15 mi) east of Montrose. The habitat consists of
15,039 ha (37,161 ac) of patches of sagebrush habitat fragmented by
oakbrush and irrigated pastures. Five leks are currently known in the
Cerro Summit-Cimarron group, but only one individual was observed on
one lek in 2010 resulting in a population estimate of 5 individuals for
the population (CDOW 2010, p. 1). Rogers (1964, p. 115) noted a small
population of sage-grouse in the Cimarron River drainage, but did not
report population numbers. He noted that lek counts at Cerro Summit in
1959 listed four individuals.
The Sims Mesa area, about 11 km (7 mi) south of Montrose, consists
of small patches of sagebrush that are heavily fragmented by pinyon-
juniper, residential and recreational development, and agriculture. The
one known lek in Sims Mesa has lacked Gunnison sage-grouse attendance
for the last six years, which indicates this population is likely
extirpated (CDOW 2009a, p. 43). In 2000, the CDOW translocated six
Gunnison sage-grouse from the Gunnison Basin to Sims Mesa (Nehring and
Apa 2000, p. 12). Rogers (1964, p. 95) recorded eight males in a lek
count at Sims Mesa in 1960. We do not know if sage-grouse move between
the Cerro Summit-Cimarron and Sims Mesa subpopulations.
Poncha Pass Population - The Poncha Pass Gunnison sage-grouse
population is located in Saguache County, approximately 16 km (10 mi)
northwest of Villa Grove, Colorado. This population was established
through the reintroduction of 30 birds from the Gunnison Basin in 1971
and 1972 during efforts to reintroduce the species to the San Luis
Valley (GSRSC 2005, p. 94). The known population distribution is in
8,262 ha (20,415 ac) of sagebrush habitat from the summit of Poncha
Pass extending south for about 13 km (8 mi) on either side of U.S.
Highway 285. Sagebrush in this area is continuous with little
fragmentation; sagebrush habitat quality throughout the area is
adequate to support the species (Nehring and Apa 2000 p. 25). San Luis
Creek runs through the area, providing a year-round water source and
lush, wet meadow riparian habitat for brood-rearing.
A high male count of 3 males was made in 2010 (CDOW 2009a, p. 121),
resulting in an estimated population size of 15 for the Poncha Pass
population (CDOW 2010, p. 3). The only current lek is located on BLM-
administered land. In 1992, a CDOW effort to simplify hunting
restrictions inadvertently opened the Poncha Pass area to sage-grouse
hunting, and at least 30 grouse were harvested from this population.
Due to declining population numbers since the 1992 hunt, CDOW
translocated 24 additional birds from the Gunnison Basin (Nehring and
Apa 2000, p. 11). In 2001 and 2002, an additional 20 and 7 birds,
respectively, were moved to Poncha Pass by the CDOW (GSRSC 2005, p.
94). Translocated females have bred successfully (Apa 2004, pers.
comm.), and display activity resumed on the historic lek in spring
2001.
Summary of Information Pertaining to the Five Factors
Section 4 of the Act (16 U.S.C. 1533), and implementing regulations
(50 CFR 424), set forth procedures for adding species to the Federal
Lists of Endangered and Threatened Wildlife and Plants. Under section
4(a)(1) of the Act, a species may be determined to be endangered or
threatened based on any of the following five factors: (1) The present
or threatened destruction, modification, or curtailment of its habitat
or range; (2) overutilization for commercial, recreational, scientific,
or educational purposes; (3) disease or predation; (4) the inadequacy
of existing regulatory mechanisms; or (5) other natural or manmade
factors affecting its continued existence. In making this finding,
information pertaining to the Gunnison sage-grouse, in relation to the
five factors provided in section 4(a)(1) of the Act, is discussed
below.
In considering what factors might constitute threats to a species,
we must look beyond the exposure of the species to a factor to evaluate
whether the species may respond to the factor in a way that causes
actual impacts to the species. If there is exposure to a factor and the
species responds negatively, the factor may be a threat and we attempt
to determine how significant a threat it is. The threat is significant
if it drives, or contributes to, the risk of extinction of the species
such that the species warrants listing as endangered or threatened as
those terms are defined in the Act.
The Gunnison Basin contains 87 percent of the current rangewide
Gunnison sage-grouse population and 62 percent of the area occupied by
the species. The remaining six populations cumulatively and
individually have substantially smaller population sizes and occupy
substantially less habitat than the Gunnison Basin population (see
Table 2).
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Sagebrush habitats within the range of Gunnison sage-grouse are
becoming increasingly fragmented as a result of various changes in land
uses and the expansion in the density and distribution of invasive
plant species (Oyler-McCance et al. 2001, pp. 329-330; Schroeder et al.
2004, p. 372). Habitat fragmentation is the separation or splitting
apart of previously contiguous, functional habitat components of a
species. Fragmentation can result from direct habitat losses that leave
the remaining habitat in non-contiguous patches, or from alteration of
habitat areas that render the altered patches unusable to a species
(i.e., functional habitat loss). Functional habitat losses include
disturbances that change a habitat's successional state or remove one
or more habitat functions; physical barriers that preclude use of
otherwise suitable areas; or activities that prevent animals from using
suitable habitat patches due to behavioral avoidance.
A variety of human developments including roads, energy
development, and other factors that cause habitat fragmentation have
contributed to or been associated with Gunnison and greater sage-grouse
extirpation (Wisdom et al. in press, p. 18). Based on a quantitative
analysis of environmental factors most closely associated with
extirpation, no strongholds (areas where the risk of Gunnison sage-
grouse extirpation is low) exist (Wisdom et al. in press, p. 26).
Estimating the impact of habitat fragmentation on sage-grouse is
complicated by time lags in response to habitat changes (Garton et al.,
in press, p. 71), particularly since these relatively long-lived birds
will continue to return to altered breeding areas (leks, nesting areas,
and early brood-rearing areas) due to strong site fidelity despite
nesting or productivity failures (Rogers 1964, pp. 35-40; Wiens and
Rotenberry 1985, p. 666; Young 1994, p. 42; Lyon
[[Page 59813]]
2000, p. 20, Connelly et al. 2004, p. 45; Holloran and Anderson 2005,
p. 747).
Habitat fragmentation can have an adverse effect on Gunnison sage-
grouse populations. Many of the factors that result in fragmentation
may be exacerbated by the effects of climate change, which may
influence long-term habitat and population trends. The following
sections examine factors that can contribute to habitat fragmentation
to determine whether they threaten Gunnison sage-grouse and their
habitat.
Historic Modification of Gunnison Sage-grouse Habitat
The historic and current distribution of the Gunnison sage-grouse
closely matches the distribution of sagebrush. Potential Gunnison sage-
grouse range is estimated to have been 5,536,358 ha (13,680,640 ac)
historically (GSRSC 2005, p. 32). Gunnison sage-grouse currently occupy
approximately 379,464 ha (937,676 ac) in southwestern Colorado and
southeastern Utah (CDOW 2009b, p. 1; GSRSC 2005, p. 81), an area that
represents approximately 7 percent of the species' potential historic
range. The following describes the factors affecting Gunnison sage-
grouse and Gunnison sage-grouse habitat within the current range of the
species.
The onset of EuroAmerican settlement in the late 1800s resulted in
significant alterations to sagebrush ecosystems throughout North
America (West and Young 2000, pp. 263-265; Miller et al. in press, p.
6), primarily as a result of urbanization, agricultural conversion, and
irrigation projects. Areas that supported basin big sagebrush
(Artemisia tridentata ssp. tridentata) were among the first sagebrush
community types converted to agriculture because their typical soils
and topography are well suited for agriculture (Rogers 1964, p. 13).
In southwestern Colorado, Oyler-McCance et al. (2001, p. 326) found
that, between 1958 and 1993, 20 percent (155,673 ha (384,676 ac)) of
sagebrush was lost in Colorado, and 37 percent of sagebrush plots
examined were fragmented. In another analysis, it was estimated that
approximately 342,000 ha (845,000 ac) of sagebrush, or 13 percent of
the pre-EuroAmerican settlement sagebrush extent, were lost in
Colorado, which includes both greater sage-grouse and Gunnison sage-
grouse habitat (Boyle and Reeder 2005, p. 3-3). However, the authors
noted that the estimate of historic sagebrush area used in their
analyses was conservative, possibly resulting in a substantial
underestimate of historic sagebrush losses (Boyle and Reeder 2005, p.
3-4). Within the range of Gunnison sage-grouse, the principal areas of
sagebrush loss were in the Gunnison Basin, San Miguel Basin, and areas
near Dove Creek, Colorado. The authors point out that the rate of loss
in the Gunnison Basin was lower than other areas of sagebrush
distribution in Colorado. The Gunnison Basin contains approximately
250,000 ha (617,000 ac) of sagebrush; this area partially comprises
other habitat types such as riparian areas and patches of non-sagebrush
vegetation types, including aspen forest, mixed-conifer forest, and
oakbrush (Boyle and Reeder 2005, p. 3-3). Within the portion of the
Gunnison Basin currently occupied by Gunnison sage-grouse, 170,000 ha
(420,000 ac) comprises exclusively sagebrush vegetation types, as
derived from Southwest Regional Gap Analsis Project (SWReGAP) landcover
data (multi-season satellite imagery acquired between 1999 and 2001)
(USGS 2004, entire).
Conversion to Agriculture
While sage-grouse may forage on agricultural croplands, they avoid
landscapes dominated by agriculture (Aldridge et al. 2008, p. 991).
Influences resulting from agricultural activities extend into adjoining
sagebrush, and include increased predation and reduced nest success due
to predators associated with agriculture (Connelly et al. 2004, p. 7-
23). Agricultural conversion can provide some limited benefits for
sage-grouse. Some crops, such as alfalfa (Medicago sativa) and young
bean sprouts (Phaseolus spp.), are eaten or used for cover by Gunnison
sage-grouse (Braun 1998, pers. comm.). However, crop monocultures do
not provide adequate year-round food or cover (GSRSC 2005, pp. 22-30).
Current Agriculture in All Gunnison Sage-grouse Population Areas -
The following estimates of land area dedicated to agriculture
(including grass/forb pasture) were derived from SWReGAP landcover data
(USGS 2004, entire). Habitat conversion to agriculture is most
prevalent in the Monticello-Dove Creek population area where
approximately 23,220 ha (57,377 ac) or 51 percent of Gunnison sage-
grouse occupied range is currently in agricultural production. In the
Gunnison Basin, approximately 20,754 ha (51,285 ac) or 9 percent of the
occupied range is currently in agricultural production. Approximately
6,287 ha (15,535 ac) or 15 percent of the occupied range in the San
Miguel Basin is currently in agricultural production. In the Cerro
Summit-Cimarron-Sims Mesa population, approximately 14 percent (5,133
ha (2,077 ac)) of the occupied range is currently in agricultural
production. Habitat conversion due to agricultural activities is
limited in the Crawford, Pinon Mesa, and Poncha Pass populations, with
3 percent or less of the occupied range currently in agricultural
production in each of the population areas.
Other than in Gunnison County, total area of harvested cropland has
declined over the past two decades in all counties within the occupied
range of Gunnison sage-grouse (USDA NASS 2010, entire). Information on
the amount of land area devoted to cropland was not available for
Gunnison County, most likely because the majority of agricultural land
use in the county is for hay production. However, total area in hay
production has correspondingly declined in Gunnison County over the
past two decades (USDA NASS 2009, p. 1). Because of this long-term
trend in reduced land area devoted to agriculture, we do not expect a
significant amount of Gunnison sage-grouse habitat to be converted to
agricultural purposes in the future.
Conservation Reserve Program - The loss of Gunnison sage-grouse
habitat to conversion to agriculture has been mitigated somewhat by the
Conservation Reserve Program (CRP). The CRP is administered by the
United States Department of Agriculture (USDA) Farm Service Agency
(FSA) and provides incentives to agricultural landowners to convert
certain cropland to more natural vegetative conditions. Except in
emergency situations, CRP-enrolled lands are not hayed or grazed.
Lands within the occupied range of Gunnison sage-grouse enrolled
into the CRP are limited to Dolores and San Miguel counties in
Colorado, and San Juan County in Utah (USDA FSA 2010, entire). From
2000 to 2008, CRP-enrollment averaged 10,622 ha (26,247 ac) in Dolores
County, 1,350 ha (3,337 ac) in San Miguel County, and 14,698 ha (36,320
ac) in San Juan County (USDA FSA 2010, entire). These CRP enrolled
areas potentially constitute approximately 56 percent of the
Monticello-Dove Creek population and 3 percent of the San Miguel
population; however, we are unsure of the proportion of these CRP lands
that are within Gunnison sage-grouse habitat. Approximately 735 ha
(1,816 ac) of leases on these CRP-enrolled lands expired on September
30, 2009, and 10,431 ha (25,778 ac) are due to expire on September 30,
2010 (UDWR 2009, p. 7).
In San Juan County, Gunnison sage-grouse use CRP lands in
proportion to their availability (Lupis et al. 2006, p. 959). The CRP
areas are used by grouse primarily as brood-rearing habitat, but
[[Page 59814]]
these areas vary greatly in plant diversity and forb abundance, and
generally lack any shrub cover (Lupis et al. 2006, pp. 959-960). In
response to a severe drought, four CRP parcels totaling 1,487 ha (3,674
ac) in San Juan County, UT, were emergency grazed for a duration of 1
to 2 months in the summer of 2002 (Lupis 2006, p. 959).
Largely as a result of agricultural conversion, sagebrush patches
in the Monticello-Dove Creek subpopulation area have progressively
become smaller and more fragmented, which has limited the amount of
available nesting and winter habitat (GSRSC 2005, pp. 82, 276).
Overall, the CRP has protected a portion of the Monticello-Dove Creek
population from more intensive agricultural use and development.
However, the overall value of CRP lands is limited because they largely
lack sagebrush cover required by Gunnison sage-sage grouse throughout
most of the year. The CRP was renewed under the Food, Conservation, and
Energy Act of 2008. A new CRP sign-up for individual landowners is not
anticipated until 2012 and the extent to which existing CRP lands will
be re-enrolled is unknown (UDWR 2009, p. 4).
Summary of Conversion to Agriculture
Throughout the range of Gunnison sage-grouse there is a declining
trend in the amount of land area devoted to agriculture. Therefore,
although we expect a large proportion of land currently in agricultural
production to remain so indefinitely, we do not expect significant
additional, future habitat conversion to agriculture within the range
of Gunnison sage-grouse. The loss of sagebrush habitat from 1958 to
1993 was estimated to be approximately 20 percent throughout the range
of Gunnison sage-grouse (Oyler-McCance et al. 2001, p. 326). The
exception is the Monticello-Dove Creek population where more than half
of the occupied range is currently in agriculture or other land uses
incompatible with Gunnison sage-grouse conservation. This habitat loss
is being somewhat mitigated by the current enrollment of lands in the
CRP. Even so, this relative scarcity of sagebrush cover indicates a
high risk of population extirpation (Wisdom et al. in press, p. 19) for
this population. Because of its limited extent, we do not consider the
conversion of sagebrush habitats to agriculture alone to be a current
or future significant threat to Gunnison sage-grouse and its habitat.
However, we recognize lands already converted to agriculture are
located throughout all Gunnison sage-grouse populations and are,
therefore, contributing to the fragmentation of remaining habitat.
Water Development
Water Development in All Population Areas - Irrigation projects
have resulted in loss of sage-grouse habitat (Braun 1998, p. 6).
Reservoir development in the Gunnison Basin flooded 3,700 ha (9,200
ac), or 1.5 percent of likely sage-grouse habitat (McCall 2005, pers.
comm.). Three other reservoirs inundated approximately 2 percent of
habitat in the San Miguel Basin population area (Garner 2005, pers.
comm.). We are unaware of any plans for additional reservoir
construction. Because of the small amount of Gunnison sage-grouse
habitat lost to water development projects and the unlikelihood of
future projects, we do not consider water development alone to be a
current or future significant threat to the Gunnison sage-grouse.
However, we expect these existing reservoirs to be maintained
indefinitely, thus acting as another source of fragmentation of
Gunnison sage-grouse habitat.
Residential Development
Human population growth in the rural Rocky Mountains is driven by
the availability of natural amenities, recreational opportunities,
aesthetically desirable settings, grandiose viewscapes, and perceived
remoteness (Riebsame 1996, p. 396, 402; Theobald 1996, p. 408; Gosnell
and Travis 2005, pp. 192-197; Mitchell et al. 2002, p. 6; Hansen et al.
2005, pp. 1899-1901). This human population growth is occurring
throughout much of the range of Gunnison sage-grouse. The human
population in all counties within the range of Gunnison sage-grouse
averaged a 70 percent increase since 1980 (Colorado Department of Local
Affairs (CDOLA) 2009a, pp. 2-3). The year 2050 projected human
population for the Gunnison River basin (an area that encompasses the
majority of the current range of Gunnison sage-grouse) is expected to
be 2.3 times greater than the 2005 population (CWCB 2009, p. 15). The
population of Gunnison County, an area that supports over 80 percent of
all Gunnison sage-grouse, is predicted to more than double to
approximately 31,100 residents by 2050 (CWCB 2009, p. 53).
The increase in residential and commercial development associated
with the expanding human population is different from historic land use
patterns (Theobald 2001, p. 548). The allocation of land for resource-
based activities such as agriculture and livestock production is
decreasing as the relative economic importance of these activities
diminishes (Theobald 1996, p. 413; Sammons 1998, p. 32; Gosnell and
Travis 2005, pp. 191-192). Currently, agribusiness occupations
constitute approximately 3 percent of the total job base in Gunnison
County (CDOLAb 2009, p. 4). Recent conversion of farm and ranch lands
to housing development has been significant in Colorado (Odell and
Knight 2001, p. 1144). Many large private ranches in the Rocky
Mountains, including the Gunnison Basin, are being subdivided into both
high-density subdivisions and larger, scattered ranchettes with lots
typically greater than 14 ha (35 ac), which encompass a large, isolated
house (Riebsame 1996, p. 399; Theobald 1996, p. 408).
The resulting pattern of residential development is less associated
with existing town sites or existing subdivisions, and is increasingly
exurban in nature (Theobald et al. 1996, pp. 408, 415; Theobald 2001,
p. 546). Exurban development is described as low-density growth outside
of urban and suburban areas (Clark et al. 2009, p. 178; Theobald 2004,
p.140) with less than one housing unit per 1 ha (2.5 ac) (Theobald
2003, p. 1627; Theobald 2004, p. 139). The resulting pattern is one of
increased residential lot size and the diffuse scattering of
residential lots in previously rural areas with a premium placed on
adjacency to federal lands and isolated open spaces (Riebsame et al.
1996, p. 396, 398; Theobald 1996, pp. 413, 417; Theobald 2001, p. 546;
Brown et al. 2005, p. 1858). The residential subdivision that results
from exurban development causes landscape fragmentation (Gosnell and
Travis 2005, p. 196) primarily through the accumulation of roads,
buildings, (Theobald 1996, p. 410; Mitchell et al. 2002, p. 3) and
other associated infrastructure such as power lines, and pipelines. In
the East River Valley of Gunnison County, residential development in
the early 1990s increased road density by 17 percent (Theobald et al.
1996, p. 410). The habitat fragmentation resulting from this
development pattern is especially detrimental to Gunnison sage-grouse
because of their dependence on large areas of contiguous sagebrush
(Patterson 1952, p. 48; Connelly et al. 2004, p. 4- 1; Connelly et al.
in press a, p. 10; Wisdom et al. in press, p. 4).
Residential Development in the Gunnison Basin Population Area -
Nearly three quarters (approximately 71 percent) of the Gunnison Basin
population of Gunnison sage-grouse occurs within Gunnison County, with
the remainder occurring in Saguache
[[Page 59815]]
County. Within Gunnison County, approximately 30 percent of the
occupied range of this species occurs on private lands. We performed a
GIS analysis of parcel ownership data that was focused on the spatial
and temporal pattern of human development within occupied Gunnison
sage-grouse habitat. Some of our analyses were limited to the portion
of occupied habitat in Gunnison County because parcel data was only
available for Gunnison County and not for Saguache County. The
cumulative number of human developments has increased dramatically in
Gunnison County, especially since the early 1970s (USFWS 2010a, p. 1).
The number of new developments averaged approximately 70 per year from
the late 1800s to 1969, increasing to approximately 450 per year from
1970 to 2008 (USFWS 2010a, pp. 2-5). Furthermore, there has been an
increasing trend toward development away from major roadways (primary
and secondary paved roads) into areas that had previously undergone
very limited development in occupied Gunnison sage-grouse habitat
(USFWS 2010b, p. 7). Between 1889 and 1968, there were approximately 51
human developments located more than 1.6 km (1 mi) from a major road in
currently occupied Gunnison sage-grouse habitat. Between 1969 and 2008,
this number increased to approximately 476 developments (USFWS 2010b,
p. 7).
In order to assess the impacts of existing residential development,
we relied on two evaluations of Gunnison sage-grouse response and
habitat availability in relation to development. The first was a
landscape-scale spatial model predicting Gunnison sage-grouse nesting
probability in the Gunnison Basin (Aldridge et al. 2010, entire). The
model indicated that Gunnison sage-grouse select nest sites in areas
with moderate shrub cover, and avoid residential development within a
radius of 1.5 km (0.9 mi) (Aldridge et al. 2010, p. 18). The model was
applied to the entire Gunnison Basin population area to predict the
likelihood of Gunnison sage-grouse nesting based on data from the
western portion (Aldridge et al. 2010, p. 16). We used Aldridge et al.
(2010)'s radius of 1.5 km (0.9 mi) avoidance distance to calculate the
indirect effects likely from the current level of development within
occupied Gunnison sage-grouse habitat in Gunnison County. We found that
49 percent of the land area within the range of Gunnison sage-grouse
has at least one housing unit within a radius of 1.5 km (0.9 mi) (USFWS
2010b, p. 7). This residential development is currently compromising
the likelihood of use by Gunnison sage-grouse for nesting habitat in
these areas.
Furthermore, since early brood-rearing habitat is often in close
proximity to nest sites (Connelly et al. 2000a, p. 971), the functional
loss of nesting habitat is closely linked with the loss of early brood-
rearing habitat. Limitations in the quality and quantity of nesting and
early brood-rearing habitat are particularly problematic because
Gunnison sage-grouse population dynamics are most sensitive during
these life-history stages (GSRSC 2005, p. G-15). We recognize that the
potential percentages of habitat loss mentioned above, whether direct
or functional, will not necessarily correspond to the same percentage
loss in sage-grouse numbers. The recent efforts to conserve Gunnison
sage-grouse and their habitat within the Basin provide protection for
the foreseeable future for several areas of high-quality habitat (see
discussion in Factor D). Nonetheless, given the large landscape-level
needs of this species, we expect this current level of habitat loss,
degradation, and fragmentation, from residential development, as
described above, to substantially limit the probability of persistence
of Gunnison sage-grouse in the Gunnison Basin.
We also calculated a ``lower'' development impact scenario using
the smaller impact footprint hypothesized by the GSRSC (2005, pp. 160-
161). This analysis assumed that residential density in excess of one
housing unit per 1.3 km\2\ (0.5 mi\2\) could cause declines in Gunnison
sage-grouse populations. Within Gunnison County, 18 percent of the land
area within the range of Gunnison sage-grouse currently has a
residential density greater than one housing unit per 1.3 km\2\ (0.5
mi\2\) (USFWS 2010b, p. 8). Therefore, according to the GSRSC estimate
of potential residential impacts, human residential densities in the
Gunnison Basin population area are such that we expect they are
limiting the Gunnison sage-grouse population in at least 18 percent of
the population area.
We expect the density and distribution of human residences to
expand in the future. Based on our GIS analysis, we estimate that
approximately 20,236 ha (50,004 ac) of private lands on approximately
1,190 parcels not subject to conservation easements currently lack
human development in occupied Gunnison sage-grouse habitat in Gunnison
County (USFWS 2010b, p. 11). These lands are scattered throughout
occupied Gunnison sage-grouse habitat in the Gunnison Basin. We used
the 20,236 ha (50,004 ac) as an initial basis to assess the potential
impacts of future development. A lack of parcel data availability from
surrounding counties precluded expanding this analysis beyond Gunnison
County; however, the analysis area constitutes 71 percent of the
Gunnison Basin population area. Approximately 93 percent of occupied
Gunnison sage-grouse habitat in Gunnison County consists of parcels
greater than 14.2 ha (35 ac), allowing exemptions from some county land
development regulations. Applying a 1.7 percent average annual
population increase under a ``middle'' growth scenario (CWCB 2009, p.
56) and an average 2.29 persons per household (CDOLA 2009b, p. 6) to
the 2008 Gunnison County human population estimate results in the
potential addition of nearly 7,000 housing units to the county by 2050.
Currently, approximately two-thirds of the human population in
Gunnison County occurs within the currently mapped occupied range of
Gunnison sage-grouse. Assuming this pattern will continue, two-thirds
of the population increase will occur within occupied Gunnison sage-
grouse habitat. The above projection could potentially result in the
addition of approximately 4,630 housing units and the potential for
25,829 ha (63,824 ac) of new habitat loss, whether direct or
functional, on parcels that currently have no development. Based on the
estimated area of impact determined by Aldridge et al. (2010), this
potential functional habitat loss constitutes an additional impact of
15 percent of the current extent of the Gunnison Basin population area
(USFWS 2010b, p. 14). When combined with the existing loss, whether
direct or functional, of 49 percent of Gunnison sage-grouse nesting
habitat, the total amount of habitat subject to the indirect effects of
residential development now and in the foreseeable future increases to
64 percent.
Using the same methodology as discussed above, but applying the
estimated area of impact determined by GSRSC (2005, p. F-3), results in
a future potential functional habitat loss of 9 percent. When combined
with the existing loss, whether direct or functional, of 18 percent of
Gunnison sage-grouse habitat, an estimated 27 percent of habitat will
be functionally lost for Gunnison sage-grouse under this minimum impact
scenario. We believe that impacts to Gunnison sage-grouse implicit in
even the lower or more conservative estimates of direct and
[[Page 59816]]
functional habitat loss are limiting the persistence of the species.
We also anticipate increased housing density in many areas of
occupied Gunnison sage-grouse habitat because the anticipated number of
new housing units will exceed the number of undeveloped parcels by
nearly four times (USFWS 2010b, p. 16). Some of this anticipated
development and subsequent functional habitat loss will undoubtedly
occur on parcels that currently have existing human development, which
could lessen the effects to Gunnison sage-grouse. However, the above
calculation of an increase in future housing units is likely an
underestimate because it does not take into account the expected
increase in second home development (CDOLA 2009b, p. 7), which could
increase negative effects to Gunnison sage-grouse. The U.S. Census
Bureau only tallies the inhabitants of primary residences in population
totals. This methodology results in an underestimate of the population,
particularly in amenity communities, because of the increased number of
part-time residents inhabiting second homes and vacation homes in these
areas (Riebsame 1996, p. 397; Theobald 2001, p. 550, Theobald 2004, p.
143). In Gunnison County, approximately 90 percent of vacant housing
units were seasonal-use units (CDOLA 2009c, p. 1). The housing vacancy
rate, which is computed by dividing the number of vacant housing units
by the total housing units, was 42.5 percent in Gunnison County over
the last two decades (CDOLA 2009d, p. 2).
We expect some development to be moderated by the establishment of
additional voluntary landowner conservation easements such as those
currently facilitated by the CDOW and land trust organizations. While
conservation easements can minimize the overall impacts to Gunnison
sage-grouse, because less than 5 percent of occupied Gunnison sage-
grouse habitat in the Gunnison Basin has been placed in conservation
easements to date, we do not expect the amount of land potentially
placed in future easements will significantly offset the overall
affects of human development.
Our analyses, based on the evaluations of impacts to Gunnison sage-
grouse discussed above, result in estimates of existing functional
habitat loss of 18 to 49 percent of the Gunnison Basin population area.
Future estimates of functional habitat loss result in an increase of 9
to 15 percent, for a cumulative total of 27 and 64 percent loss of the
Gunnison Basin population area. We believe that impacts within these
ranges limit the persistence of Gunnison sage-grouse.
Residential Development in All Other Population Areas - In 2004,
within the Crawford Population area, approximately 951 ha (2,350 ac),
or 7 percent of the occupied Gunnison sage-grouse habitat, was
subdivided into 48 parcels ranging in size from 14.2 ha (35 ac) to 28.3
ha (70 ac) (CDOW 2009a, p. 59). Local landowners and the National Park
Service (NPS) have ongoing efforts to protect portions of the
subdivided area through conservation easements. Residential subdivision
continues to occur in the northern part of the Poncha Pass population
area, and the CDOW considers this to be the highest priority threat to
this population (CDOW 2009a, p. 124). The rate of residential
development in the San Miguel Basin population increased between 2005
and 2008 but slowed in 2009 (CDOW 2009a, p. 135). However, a 429 ha
(1,057 ac) parcel north of Miramonte Reservoir is currently being
developed as a retreat. The CDOW reports that potential impacts to
Gunnison sage-grouse resulting from the development may be reduced by
possibly placing a portion of the property into a conservation easement
and the relocation of a proposed major road to avoid occupied habitat
(CDOW 2009a, p. 136). No recent or planned residential developments are
known for the Cerro Summit-Cimarron-Sims Mesa population area (CDOW
2009a, p. 45), Monticello-Dove Creek population area (CDOW 2009a, p.
73), or Pinon Mesa population area (CDOW 2009a, p. 109). The remaining
limited amounts of habitat, the fragmented nature of this remaining
habitat, and the anticipated increases in exurban development within
each of the six smaller populations pose a significant threat to these
six populations.
Summary of Residential Development
Because Gunnison sage-grouse are dependent on expansive, contiguous
areas of sagebrush habitat to meet their life-history needs, the
development patterns described above have resulted in the direct and
functional loss of sagebrush habitat and have negatively affected the
species by limiting already scarce habitat, especially within the six
smaller populations. The collective influences of fragmentation and
disturbance from human activities around residences and associated
roads reduce the effective habitat around these areas, making them
inhospitable to Gunnison sage-grouse (Aldridge et al. 2010, pp. 24-25;
Knick, et al. 2009, in press, p. 25 and references therein; Aldridge
and Boyce 2007, p.520). Human population growth that results in a
dispersed exurban development pattern throughout sagebrush habitats
will reduce the likelihood of sage-grouse persistence in these areas.
Human populations are increasing throughout the range of Gunnison sage-
grouse, and we expect this trend to continue. Given the current
demographic trends described above, we believe the rate of residential
development in Gunnison sage-grouse habitat will continue at least
through 2050, and likely longer. The resulting habitat loss and
fragmentation from residential development is a significant threat to
Gunnison sage-grouse now and in the foreseeable future.
Fences
The effects of fencing on sage-grouse include direct mortality
through collisions, creation of raptor and corvid (Family Corvidae:
crows, ravens, magpies, etc.) perch sites, the potential creation of
predator corridors along fences (particularly if a road is maintained
next to the fence), incursion of exotic species along the fencing
corridor, and habitat fragmentation (Call and Maser 1985, p. 22; Braun
1998, p. 145; Connelly et al. 2000a, p. 974; Beck et al. 2003, p. 211;
Knick et al. 2003, p. 612; Connelly et al. 2004, p. 1-2). Corvids are
significant sage-grouse nest predators and were responsible for more
than 50 percent of nest predations in Nevada (Coates 2007, pp. 26-30).
Sage-grouse frequently fly low and fast across sagebrush flats, and
fences can create a collision hazard resulting in direct mortality
(Call and Maser 1985, p. 22). Not all fences present the same mortality
risk to sage-grouse. Mortality risk appears to be dependent on a
combination of factors including design of fencing, landscape
topography, and spatial relationship with seasonal habitats
(Christiansen 2009). This variability in fence mortality rate and the
lack of systematic fence monitoring make it difficult to determine the
magnitude of impacts to sage-grouse populations; however, in some cases
the level of mortality is likely significant to localized areas within
populations. Fences directly kill greater sage grouse (Call and Maser
1985, p. 22; Christiansen 2009, pp. 1-2); we assume that Gunnison sage-
grouse are also killed by fences but do not have species-specific data.
Although the effects of direct strike mortality on populations are not
fully analyzed, fences are ubiquitous across the landscape. Fence
collisions continue to be identified as a source of mortality for
Gunnison and greater sage-grouse and we expect this source of mortality
to continue into the foreseeable future (Braun 1998, p. 145;
[[Page 59817]]
Connelly et al. 2000a, p. 974; Oyler-McCance et al. 2001, p. 330;
Connelly et al. 2004, p. 7-3).
Fence posts create perching places for raptors and corvids, which
may increase their ability to prey on sage-grouse (Braun 1998, p. 145;
Oyler-McCance et al. 2001, p. 330; Connelly et al. 2004, p. 13-12). We
anticipate that the effect on sage-grouse populations through the
creation of new raptor perches and predator corridors into sagebrush
habitats is similar to that of powerlines discussed below (Braun 1998,
p. 145; Connelly et al. 2004, p. 7-3). Fences and their associated
roads also facilitate the spread of invasive plant species that replace
sagebrush plants upon which sage-grouse depend (Braun 1998, p. 145;
Connelly et al. 2000a, p. 973; Gelbard and Belnap 2003, p. 421;
Connelly et al. 2004, p. 7-3). Greater sage-grouse avoidance of habitat
adjacent to fences, presumably to minimize the risk of predation,
effectively results in habitat fragmentation even if the actual habitat
is not removed (Braun 1998, p. 145). Because of similarities in
behavior and habitat use, we believe the response of Gunnison sage-
grouse is similar to that observed in greater sage-grouse.
At least 1,540 km (960 mi) of fence are on BLM lands within the
Gunnison Basin (Borthwick 2005a, pers. comm.; BLM 2005a, 2005e) and an
unquantified amount of fence on land owned or managed by other
landowners. Fences are present within all other Gunnison sage-grouse
population areas, but we have no quantitative information on the amount
or types of fencing in these areas.
Summary of Fences
While fences contribute to habitat fragmentation and increase the
potential for loss of individual grouse through collisions or enhanced
predation, such effects have been ongoing since the first agricultural
conversions occurred in sage-grouse habitat. We expect that the
majority of existing fences will remain on the landscape indefinitely.
However, because we do not expect a major increase in the number of
fences, particularly 3-wire range fencing, we do not believe fencing,
on its own, is a significant threat to Gunnison sage-grouse at the
species level. In the smaller Gunnison sage-grouse populations, the
impacts of fencing could become another source of mortality that
cumulatively affects the species. We also recognize that fences are
located throughout all Gunnison sage-grouse populations and are,
therefore, contributing to the fragmentation of remaining habitat.
Roads
Impacts from roads may include direct habitat loss, direct
mortality, barriers to migration corridors or seasonal habitats,
facilitation of predation and spread of invasive vegetative species,
and other indirect influences such as noise (Forman and Alexander 1998,
pp. 207-231). Greater sage-grouse mortality resulting from collisions
with vehicles does occur, but mortalities are typically not monitored
or recorded (Patterson 1952, p. 81). Therefore, we are unable to
determine the importance of this factor on sage-grouse populations. We
have no information on the number of direct mortalities of Gunnison
sage-grouse resulting from vehicles or roads; however, because of
similarities in their habitat and habitat use, we expect similar
effects as those observed in greater sage-grouse. Roads within Gunnison
sage-grouse habitats have been shown to impede movement of local
populations between the resultant patches, with road avoidance
presumably being a behavioral means to limit exposure to predation
(Oyler-McCance et al. 2001, p. 330).
The presence of roads increases human access and resulting
disturbance effects in remote areas (Forman and Alexander 1998, p. 221;
Forman 2000, p. 35; Connelly et al. 2004, pp. 7-6 to 7-25). In
addition, roads can provide corridors for predators to move into
previously unoccupied areas. For some mammalian species known to prey
on sage-grouse, such as red fox (Vulpes vulpes), raccoons (Procyon
lotor), and striped skunks (Mephitis mephitis), dispersal along roads
has greatly increased their distribution (Forman and Alexander 1998, p.
212; Forman 2000, p. 33; Frey and Conover 2006, pp. 1114-1115). Corvids
also use linear features such as primary and secondary roads as travel
routes, expanding their movements into previously unused regions
(Knight and Kawashima 1993, p. 268; Connelly et al. 2004, p. 12-3).
Corvids are significant sage-grouse nest predators and were responsible
for more than 50 percent of nest predations in Nevada (Coates 2007, pp.
26-30). Ravens were documented following roads in oil and gas fields
while foraging (Bui 2009, p. 31).
The expansion of road networks contributes to exotic plant
invasions via introduced road fill, vehicle transport, and road
maintenance activities (Forman and Alexander 1998, p. 210; Forman 2000,
p. 32; Gelbard and Belnap 2003, p. 426; Knick et al. 2003, p. 619;
Connelly et al. 2004, p. 7-25). Invasive species are not limited to
roadsides, but also encroach into surrounding habitats (Forman and
Alexander 1998, p. 210; Forman 2000, p. 33; Gelbard and Belnap 2003, p.
427). In their study of roads on the Colorado Plateau of southern Utah,
Gelbard and Belnap (2003, p. 426) found that improving unpaved four-
wheel drive roads to paved roads resulted in increased cover of exotic
plant species within the interior of adjacent plant communities. This
effect was associated with road construction and maintenance activities
and vehicle traffic, and not with differences in site characteristics.
The incursion of exotic plants into native sagebrush systems can
negatively affect Gunnison sage-grouse through habitat losses and
conversions (see further discussion below in Invasive Plants).
Additional indirect effects of roads may result from birds'
behavioral avoidance of road areas because of noise, visual
disturbance, pollutants, and predators moving along a road. The
landscape-scale spatial model predicting Gunnison sage-grouse nest site
selection showed strong avoidance of areas with high road densities of
roads classed 1 through 4 (primary paved highways through primitive
roads with 2-wheel drive sedan clearance) within 6.4 km (4 mi)) of nest
sites (Aldridge et al. 2010 p. 18). The occurrence of Gunnison sage-
grouse nest sites also decreased with increased proximity to primary
and secondary paved highways (roads classes 1 and 2) (Aldridge et al.
2010, p. 27). Male greater sage-grouse lek attendance was shown to
decline within 3 km (1.9 mi) of a methane well or haul road with
traffic volume exceeding one vehicle per day (Holloran 2005, p. 40).
Male sage-grouse depend on acoustical signals to attract females to
leks (Gibson and Bradbury 1985, p. 82; Gratson 1993, p. 692). If noise
interferes with mating displays, and thereby female attendance, younger
males will not be drawn to the lek and eventually leks will become
inactive (Amstrup and Phillips 1977, p. 26; Braun 1986, pp. 229-230).
In a study on the Pinedale Anticline in Wyoming, greater sage-
grouse hens that bred on leks within 3 km (1.9 mi) of roads associated
with oil and gas development traveled twice as far to nest as did hens
that bred on leks greater than 3 km (1.9 mi) from roads. Nest
initiation rates for hens bred on leks close to roads also were lower
(65 versus 89 percent), affecting population recruitment (33 versus 44
percent) (Lyon 2000, p. 33; Lyon and Anderson 2003, pp. 489-490). Lyon
and Anderson (2003, p. 490) suggested that roads may be the primary
impact of oil and gas
[[Page 59818]]
development to sage-grouse, due to their persistence and continued use
even after drilling and production have ceased. Lek abandonment
patterns suggested that daily vehicular traffic along road networks for
oil wells can impact greater sage-grouse breeding activities (Braun et
al. 2002, p. 5). We believe the effects of vehicular traffic on
Gunnison sage-grouse, regardless of its purpose (e.g., in support of
energy production or local commuting and recreation), are similar to
those observed in greater sage-grouse.
Aldridge et al. (2008, p. 992) did not find road density to be an
important factor affecting greater sage-grouse persistence or rangewide
patterns in sage-grouse extirpation. However, the authors did not
consider the intensity of human use of roads in their modeling efforts.
They also indicated that their analyses may have been influenced by
inaccuracies in spatial road data sets, particularly for secondary
roads (Aldridge et al. 2008, p. 992). Historic range where greater and
Gunnison sage grouse have been extirpated has a 25 percent higher
density of roads than occupied range (Wisdom et al. in press, p. 18).
Wisdom et al.'s (in press) greater and Gunnison sage-grouse rangewide
analysis supports the findings of numerous local studies showing that
roads can have both direct and indirect impacts on sage-grouse
distribution and individual fitness (reproduction and survival) (e.g.,
Lyon and Anderson 2003 p. 490 , Aldridge and Boyce 2007, p. 520).
Recreational activities including off highway vehicles (OHV), all-
terrain vehicles (ATV), motorcycles, mountain biking and other
mechanized methods of travel have been recognized as a potential direct
and indirect threat to Gunnison sage-grouse and their habitat (BLM
2009, p. 36). In Colorado, the number of annual off highway vehicle
(OHV) registrations has increased from 12,000 in 1991 to 131,000 in
2007 (BLM 2009, p. 37). Four wheel drive, OHV, motorcycle, specialty
vehicle, and mountain bike use is expected to increase in the future
based on increased population in general and increased population
density in the area (as discussed above). Numerous off-road routes and
access points to habitat used by Gunnison sage-grouse combined with
increasing capabilities for mechanized travel and increased human
population further contribute to habitat fragmentation.
Roads in the Gunnison Basin Population Area - On BLM lands in the
Gunnison Basin there are currently 2,050 km (1,274 mi) of roads within
6.4 km (4 mi) of Gunnison sage-grouse leks. Eighty-seven percent of all
Gunnison sage-grouse nests were located less than 6.4 km (4 mi) from
the lek of capture (Apa 2004, p. 21). However, the BLM proposes to
reduce road length to 1,157 km (719 mi) (BLM 2010, p. 147). Currently,
1,349 km (838 mi) of roads accessible to 2-wheel drive passenger cars
exist in occupied Gunnison sage-grouse habitat in the Gunnison Basin.
Four-wheel-drive vehicle roads, as well as motorcycle, mountain bike,
horse, and hiking trails are heavily distributed throughout the range
of Gunnison sage-grouse (BLM 2009, pp. 27, 55, 86), which further
increases the overall density of roads and their direct and indirect
effects on Gunnison sage-grouse. User-created roads and trails have
increased since 2004 (BLM 2009, p. 33), although we do not know the
percentage increase.
Using a spatial dataset of roads in the Gunnison Basin we performed
GIS analyses on the potential effects of roads to Gunnison sage-grouse
and their habitat. To account for secondary effects from invasive weed
spread from roads (see discussion below in Invasive Plants), we applied
a 0.7 km (0.4 mi) buffer (Bradley and Mustard 2006, p. 1146) to all
roads in the Gunnison Basin. Results of these analyses indicate that
approximately 85 percent of occupied habitat in the Gunnison Basin has
an increased likelihood of current or future road-related invasive weed
invasion. When all roads in the Gunnison basin are buffered by 6.4 km
(4 mi) or 9.6 km (6 mi) to account for nesting avoidance (Aldridge et
al. 2010, p. 27) and secondary effects from mammal and corvid foraging
areas (Knick et al in press, p. 113), respectively, all occupied
habitat in the Gunnison Basin is indirectly affected by roads.
Roads in All Other Population Areas - Approximately 140 km (87 mi),
243 km (151 mi), and 217 km (135 mi) of roads (all road classes) occur
on BLM lands within the Cerro Summit-Cimarron-Sims Mesa, Crawford, and
San Miguel Basin population areas, respectively, all of which are
managed by the BLM (BLM 2009, p. 71). We do not have information on the
total length of roads within the Monticello-Dove Creek, Pinon Mesa, or
Poncha Pass Gunnison sage-grouse populations. However, several maps
provided by the BLM show that roads are widespread and common
throughout these population areas (BLM 2009, pp. 27, 55, 86).
Summary of Roads
As described above in the `Residential Development' section, the
human population is increasing throughout the range of Gunnison sage-
grouse (CDOLA 2009a, pp. 2-3; CWCB 2009, p. 15), and we have no data
indicating this trend will be reversed. Gunnison sage-grouse are
dependent on large contiguous and unfragmented landscapes to meet their
life-history needs (GSRSC 2005, pp. 26-30), and the existing road
density throughout much of the range of Gunnison sage-grouse has
negatively affected the species. The collective influences of
fragmentation and disturbance from roads reduce the effective habitat
around these areas making them inhospitable to sage-grouse (Aldridge et
al. 2010, pp. 24-25; Aldridge and Boyce 2007, p. 520; Knick et al.
2009, in press, p. 25 and references therein). Given the current human
demographic and economic trends described above in the Residential
Development section, we believe that increased road use and increased
road construction associated with residential development will continue
at least through 2050, and likely longer. The resulting habitat loss,
degradation, and fragmentation from roads is a significant threat to
Gunnison sage-grouse now and in the foreseeable future.
Powerlines
Powerlines can directly affect greater sage-grouse by posing a
collision and electrocution hazard (Braun 1998, pp. 145-146; Connelly
et al. 2000a, p. 974), and can have indirect effects by decreasing lek
recruitment (Braun et al. 2002, p. 10), increasing predation (Connelly
et al. 2004, p. 13-12), fragmenting habitat (Braun 1998, p. 146), and
facilitating the invasion of exotic annual plants (Knick et al. 2003,
p. 612; Connelly et al. 2004, p. 7-25). Proximity to powerlines is
associated with Gunnison and greater sage-grouse extirpation (Wisdom et
al. in press, p. 20). Due to the potential spread of invasive species
and predators as a result of powerline construction and maintenance,
the impact from a powerline is greater than its actual footprint. We
believe the effects to Gunnison sage-grouse are similar to those
observed in greater sage-grouse and that the impact from a powerline is
greater than its footprint.
In areas where the vegetation is low and the terrain relatively
flat, power poles provide an attractive hunting and roosting perch, as
well as nesting stratum for many species of raptors and corvids
(Steenhof et al. 1993, p. 27; Connelly et al. 2000a, p. 974; Manville
2002, p. 7; Vander Haegen et al. 2002, p. 503). Power poles increase a
raptor's range of vision, allow for greater speed during attacks on
prey, and serve as
[[Page 59819]]
territorial markers (Steenhof et al. 1993, p. 275; Manville 2002, p.
7). Raptors may actively seek out power poles where natural perches are
limited. For example, within 1 year of construction of a 596-km (3-2 -
mi) transmission line in southern Idaho and Oregon, raptors and common
ravens began nesting on the supporting poles (Steenhof et al. 1993, p.
275). Within 10 years of construction, 133 pairs of raptors and ravens
were nesting along this stretch (Steenhof et al. 1993, p. 275). Raven
counts increased by approximately 200 percent along the Falcon-Gondor
transmission line corridor in Nevada within 5 years of construction
(Atamian et al. 2007, p. 2). The increased abundance of raptors and
corvids within occupied greater and Gunnison sage-grouse habitats can
result in increased predation. Ellis (1985, p. 10) reported that golden
eagle (Aquila chryrsaetos) predation on sage-grouse on leks increased
from 26 to 73 percent of the total predation after completion of a
transmission line within 200 meters (m) (220 yards (yd)) of an active
sage-grouse lek in northeastern Utah. The lek was eventually abandoned,
and Ellis (1985, p. 10) concluded that the presence of the powerline
resulted in changes in sage-grouse dispersal patterns and caused
fragmentation of the habitat. Golden eagles are found throughout the
range of Gunnison sage-grouse (USGS 2010, p. 1), and golden eagles were
found to be the dominant species recorded perching on power poles in
Utah in Gunnison sage-grouse habitat (Prather and Messmer 2009, p. 12).
Leks within 0.4 km (0.25 mi) of new powerlines constructed for
coalbed methane development in the Powder River Basin of Wyoming had
significantly lower growth rates, as measured by recruitment of new
males onto the lek, compared to leks further from these lines,
presumably resulting from increased raptor predation (Braun et al.
2002, p. 10). Within their analysis area, Connelly et al. (2004, p. 7-
26) assumed a 5 to 6.9-km (3.1 to 4.3-mi) radius buffer around the
perches, based on the average foraging distance of these corvids and
raptors, and estimated that the area potentially influenced by
additional perches provided by powerlines was 672,644 to 837,390 km\2\
(259,641 to 323,317 mi\2\), or 32 to 40 percent of their assessment
area. The actual impact on an area would depend on corvid and raptor
densities within the area (see discussion in Factor C, below).
The presence of a powerline may fragment sage-grouse habitats even
if raptors are not present. The use of otherwise suitable habitat by
sage-grouse near powerlines increased as distance from the powerline
increased for up to 600 m (660 yd) (Braun 1998, p. 8). Based on those
unpublished data, Braun (1998, p. 8) reported that the presence of
powerlines may limit Gunnison and greater sage-grouse use within 1 km
(0.6 mi) in otherwise suitable habitat. Similar results were recorded
for other grouse species. For example, lesser and greater prairie-
chickens (Tympanuchus pallidicinctus and T. cupido, respectively)
avoided otherwise suitable habitat near powerlines (Pruett et al. 2009,
p. 6). Additionally, both species also crossed powerlines less often
than nearby roads, which suggests that powerlines are a particularly
strong barrier to movement (Pruett et al. 2009, p. 6).
Sage-grouse also may avoid powerlines as a result of the
electromagnetic fields present (Wisdom et al. in press, p. 19).
Electromagnetic fields have been demonstrated to alter the behavior,
physiology, endocrine systems and immune function in birds, with
negative consequences on reproduction and development (Fernie and
Reynolds 2005, p. 135). Birds are diverse in their sensitivities to
electromagnetic field exposures, with domestic chickens being very
sensitive. Many raptor species are less affected (Fernie and Reynolds
2005, p. 135). No studies have been conducted specifically on sage-
grouse. Therefore, we do not know the impact to the Gunnison sage-
grouse from electromagnetic fields.
Linear corridors through sagebrush habitats can facilitate the
spread of invasive species, such as cheatgrass (Bromus tectorum)
(Gelbard and Belnap 2003, pp. 424-426; Knick et al. 2003, p. 620;
Connelly et al. 2004, p. 1-2). However, we were unable to find any
information regarding the amount of invasive species incursion as a
result of powerline construction.
Powerlines in the Gunnison Basin Population Area - On approximately
121,000 ha (300,000 ac) of BLM land in the Gunnison Basin, 36 rights-
of-way for power facilities, power lines, and transmission lines have
resulted in the direct loss of 350 ha (858 ac) of occupied habitat
(Borthwick 2005b, pers comm.). As discussed above, the impacts of these
lines likely extend beyond their actual footprint. We performed a GIS
analysis of transmission line location in relation to overall habitat
area and Gunnison sage-grouse lek locations in the Gunnison Basin
Population area to obtain an estimate of the potential effects in the
Basin. Results of these analyses indicate that 68 percent of the
Gunnison Basin population area is within 6.9 km (4.3 mi) of an
electrical transmission line and is potentially influenced by avian
predators utilizing the additional perches provided by transmission
lines. This area contains 65 of 109 active leks (60 percent) in the
Gunnison Basin population. These results suggest that potential
increased predation resulting from transmission lines have the
potential to affect a substantial portion of the Gunnison Basin
population.
Powerlines in All Other Population Areas - A transmission line runs
through the Dry Creek Basin group in the San Miguel Basin population,
and the Beaver Mesa group has two transmission lines. None of the
transmission lines in the San Miguel Basin have raptor proofing, nor do
most distribution lines (Ferguson 2005, pers comm.) so their use by
raptors and corvids as perch sites for hunting and use for nest sites
is not discouraged. One major electric transmission line runs east-west
in the northern portion of the current range of the Monticello group
(San Juan County Gunnison Sage-grouse Working Group (GSWG) 2005, p.
17). Powerlines do not appear to be present in sufficient density to
pose a significant threat to Gunnison sage-grouse in the Pinon Mesa
population at this time. One transmission line parallels Highway 92 in
the Crawford population, and distribution lines run from there to homes
on the periphery of the current range (Ferguson 2005, pers. comm.).
Summary of Powerlines
The projected human population growth rate in and near most
Gunnison sage-grouse populations is high (see discussion under
Residential Development). As a result, we expect an associated increase
in distribution powerlines. Powerlines are likely negatively affecting
Gunnison sage-grouse as they contribute to habitat loss and
fragmentation and facilitation of predators of Gunnison sage-grouse.
Given the current demographic and economic trends described above, we
believe that existing powerlines and anticipated distribution of
powerlines associated with residential development will continue at
least through 2050, and likely longer. The resulting habitat loss and
fragmentation from powerlines, and the effects of avian predators that
use them, is a significant threat to Gunnison sage-grouse now and in
the foreseeable future.
Fire
The nature of historical fire patterns in sagebrush communities,
particularly in Wyoming big sagebrush (Artemisia
[[Page 59820]]
tridentata var. wyomingensis), is not well understood, and a high
degree of variability likely occurred (Miller and Eddleman 2000, p. 16;
Zouhar et al. 2008, p. 154; Baker in press, p. 16). In general, mean
fire return intervals in low-lying, xeric (dry) big sagebrush
communities range from more than 100 to 350 years, and return intervals
decrease from 50 to more than 200 years in more mesic (wet) areas, at
higher elevations, during wetter climatic periods, and in locations
associated with grasslands (Baker 2006, p. 181; Mensing et al. 2006, p.
75; Baker, in press, pp. 15-16; Miller et al., in press, p. 35).
Mountain big sagebrush (Artemisia tridenata var. vaseyana), the
most important and widespread sagebrush species for Gunnison sage-
grouse, is killed by fire and can require decades to recover. In
nesting and wintering sites, fire causes direct loss of habitat due to
reduced cover and forage (Call and Maser 1985, p. 17). While there may
be limited instances where burned habitat is beneficial, these gains
are lost if alternative sagebrush habitat is not readily available
(Woodward 2006, p. 65).
Herbaceous understory vegetation plays a critical role throughout
the breeding season as a source of forage and cover for Gunnison sage-
grouse females and chicks. The response of herbaceous understory
vegetation to fire varies with differences in species composition, pre-
burn site condition, fire intensity, and pre- and post-fire patterns of
precipitation. In general, when not considering the synergistic effects
of invasive species, any beneficial short-term flush of understory
grasses and forbs is lost after only a few years and little difference
is apparent between burned and unburned sites (Cook et al. 1994, p.
298; Fischer et al. 1996, p. 196; Crawford 1999, p. 7; Wrobleski 1999,
p. 31; Nelle et al. 2000, p. 588; Paysen et al. 2000, p. 154; Wambolt
et al. 2001, p. 250).
In addition to altering plant community structure, fires can
influence invertebrate food sources (Schroeder et al. 1999, p. 5).
However, because few studies have been conducted and the results of
those available vary, the specific magnitude and duration of the
effects of fire on insect communities is still uncertain.
A clear positive response of Gunnison or greater sage-grouse to
fire has not been demonstrated (Braun 1998, p. 9). The few studies that
have suggested fire may be beneficial for greater sage-grouse were
primarily conducted in mesic areas used for brood-rearing (Klebenow
1970, p. 399; Pyle and Crawford 1996, p. 323; Gates 1983, in Connelly
et al. 2000c, p. 90; Sime 1991, in Connelly et al. 2000a, p. 972). In
this type of habitat, small fires may maintain a suitable habitat
mosaic by reducing shrub encroachment and encouraging understory
growth. However, without available nearby sagebrush cover, the utility
of these sites is questionable, especially within the six small
Gunnison sage-grouse populations where fire could further degrade and
fragment the remaining habitat. Sagebrush loss as a result of fire is
likely to have proportionally more individual bird and population level
impacts as the amount of sagebrush declines within each of the
remaining populations. As the amount of sagebrush remaining within a
population declines, the greater the potential impact is to that
population.
The invasion of the exotic cheatgrass increases fire frequency
within the sagebrush ecosystem (Zouhar et al. 2008, p. 41; Miller et
al. in press, p. 39). Cheatgrass readily invades sagebrush communities,
especially disturbed sites, and changes historical fire patterns by
providing an abundant and easily ignitable fuel source that facilitates
fire spread. While sagebrush is killed by fire and is slow to
reestablish, cheatgrass recovers within 1 to 2 years of a fire event
(Young and Evans 1978, p. 285). This annual recovery leads to a readily
burnable fuel source and ultimately a reoccurring fire cycle that
prevents sagebrush reestablishment (Eiswerth et al. 2009, p. 1324). The
extensive distribution and highly invasive nature of cheatgrass poses
substantial increased risk of fire and permanent loss of sagebrush
habitat, as areas disturbed by fire are highly susceptible to further
invasion and ultimately habitat conversion to an altered community
state. For example, Link et al. (2006, p. 116) show that risk of fire
increases from approximately 46 to 100 percent when ground cover of
cheatgrass increases from 12 to 45 percent or more. We do not have a
reliable estimate of the amount of area occupied by cheatgrass in the
range of Gunnison sage-grouse. However, cheatgrass is found at numerous
locations throughout the Gunnison Basin (BLM 2009, p. 60).
Fire in the Gunnison Basin Population Area - Six prescribed burns
have occurred on BLM lands in the Gunnison Basin since 1984, totaling
approximately 409 ha (1,010 ac) (BLM 2009, p. 35). The fires created
large sagebrush-free areas that were further degraded by poor post-burn
livestock management (BLM 2005a, p. 13). As a result, these areas are
no longer suitable as Gunnison sage-grouse habitat. Approximately 8,470
ha (20,930 ac) of prescribed burns occurred on Forest Service lands in
the Gunnison Basin since 1983 (USFS 2009, p. 1). A small wildfire on
BLM lands near Hartman Rocks burned 8 ha (20 ac) in 2007 (BLM 2009, p.
35). The total area of occupied Gunnison sage-grouse habitat burned in
recent decades is approximately 8,887 ha (21,960 ac), which constitutes
1.5 percent of the occupied Gunnison sage-grouse habitat area.
Cumulatively, this equates to a relatively small amount of habitat
burned over a period of nearly three decades. This information suggests
that there has not been a demonstrated change in fire cycle in the
Gunnison Basin population area to date.
Fire in All Other Population Areas - Two prescribed burns conducted
in 1986 (105 ha (260 ac)) and 1992 (140 ha (350 ac)) on BLM land in the
San Miguel Basin on the north side of Dry Creek Basin had negative
impacts on sage-grouse. The burns were conducted for big game forage
improvement, but the sagebrush died and was largely replaced with weeds
(BLM 2005b, pp. 7-8). The Burn Canyon fire in the Dry Creek Basin and
Hamilton Mesa areas burned 890 ha (2,200 ac) in 2000. Three fires have
occurred in Gunnison sage-grouse habitat since 2004 on lands managed by
the BLM in the Crawford, Cerro Summit-Cimarron-Sims Mesa, and San
Miguel Basin population areas. There have been no fires since 2004 on
lands managed by the BLM within the Monticello-Dove Creek population.
Because these fires were mostly small in size, we do not believe they
resulted in substantial impacts to Gunnison sage-grouse.
Several wildfires near or within the Pinon Mesa population area
have occurred in the past 20 years. One fire burned a small amount of
occupied Gunnison sage-grouse habitat in 1995, and several fires burned
in potential Gunnison sage-grouse habitat. Individual burned areas
ranged from 3.6 ha (9 ac) to 2,160 ha (5,338 ac). A wildfire in 2009
burned 1,053 ha (2,602 ac), predominantly within vacant or unknown
Gunnison sage-grouse habitat (suitable habitat for sage-grouse that is
separated from occupied habitats that has not been adequately
inventoried, or without recent documentation of grouse presence) near
the Pinon Mesa population. Since 2004, a single 2.8 ha (7 ac) wildfire
occurred in the Cerro Summit-Cimarron-Sims Mesa population area, and
two prescribed fires, both less than 12 ha (30 ac), were implemented in
the San Miguel population area. There was no fire activity within
occupied Gunnison sage-grouse habitat in the last two decades in
[[Page 59821]]
the Poncha Pass population area (CDOW 2009a, pp. 125-126) or the
Monticello-Dove Creek population area (CDOW 2009a, p. 75; UDWR 2009, p.
5).
Summary of Fire
Fires can cause the proliferation of weeds and can degrade suitable
sage-grouse habitat, which may not recover to suitable conditions for
decades, if at all (Pyke in press, pp. 18-19). Recent fires in Gunnison
sage-grouse habitat were mostly small in size and did not result in
substantial impacts to Gunnison sage-grouse, and there has been no
obvious change in fire cycle in any Gunnison sage-grouse population
area. Therefore, we do not consider fire to be a significant threat to
Gunnison sage-grouse or its habitat at this time. It is not currently
possible to predict the extent or location of future fire events.
However, existing data indicates that climate change has the potential
to alter changes in the distribution and extent of cheatgrass and
sagebrush and associated fire frequencies. The best available data
indicates that fire frequency may increase in the foreseeable future
(which we consider to be indefinite) because of increases in cover of
cheatgrass (Zouhar et al. 2008, p. 41; Miller et al. in press, p. 39;
Whisenant 1990, p. 4) and the projected effects of climate change
(Miller et al. in press, p. 47; Prevey et al. 2009, p. 11) (see
Invasive Plants and Climate Change discussions below). Therefore, fire
is likely to become an increasingly significant threat to the Gunnison
sage-grouse in the foreseeable future.
Invasive Plants
For the purposes of this finding, we define invasive plants as
those that are not native to an ecosystem and that have a negative
impact on Gunnison sage-grouse habitat. Invasive plants alter native
plant community structure and composition, productivity, nutrient
cycling, and hydrology (Vitousek 1990, p. 7) and may cause declines in
native plant populations through competitive exclusion and niche
displacement, among other mechanisms (Mooney and Cleland 2001, p.
5446). Invasive plants reduce and, in cases where monocultures of them
occur, eliminate vegetation that sage-grouse use for food and cover.
Invasive plants do not provide quality sage-grouse habitat. Sage-grouse
depend on a variety of native forbs and the insects associated with
them for chick survival, and sagebrush, which is used exclusively
throughout the winter for food and cover.
Along with replacing or removing vegetation essential to sage-
grouse, invasive plants fragment existing sage-grouse habitat. They can
create long-term changes in ecosystem processes, such as fire-cycles
(see discussion under Fire above) and other disturbance regimes that
persist even after an invasive plant is removed (Zouhar et al. 2008, p.
33). A variety of nonnative annuals and perennials are invasive to
sagebrush ecosystems (Connelly et al. 2004, pp. 7-107 and 7-108; Zouhar
et al. 2008, p. 144). Cheatgrass is considered most invasive in
Artemisia tridentata ssp. wyomingensis communities (Connelly et al.
2004, p. 5-9). Other invasive plants found within the range of Gunnison
sage-grouse that are reported to take over large areas include: spotted
knapweed (Centaurea maculosa), Russian knapweed (Acroptilon repens),
oxeye daisy (Leucanthemum vulgare), yellow toadflax (Linaria vulgaris),
and field bindweed (Convolvulus arvensis) (BLM 2009, p. 28, 36;
Gunnison Watershed Weed Commission (GWWC) 2009, pp. 4-6). Although not
yet reported to create large expanses in the range of Gunnison sage-
grouse, the following weeds are also known from the species' range and
do cover large expanses in other parts of western North America:
diffuse knapweed (Centaurea diffusa), whitetop (Cardaria draba),
jointed goatgrass (Aegilops cylindrica), and yellow starthistle
(Centaurea solstitialis). Other invasive plant species present within
the range of Gunnison sage-grouse that are problematic yet less likely
to overtake large areas include: Canada thistle (Cirsium arvense), musk
thistle (Carduus nutans), bull thistle (Cirsium vulgare), houndstongue
(Cynoglossum officinale), black henbane (Hyoscyamus niger), common
tansy (Tanacetum vulgare), and absinth wormwood (Artemisia biennis)
(BLM 2009, p. 28, 36; GWWC 2009, pp. 4-6).
Cheatgrass impacts sagebrush ecosystems by potentially shortening
fire intervals from several decades, depending on the type of sagebrush
plant community and site productivity, to as low as 3 to 5 years,
perpetuating its own persistence and intensifying the role of fire
(Whisenant 1990, p. 4). Connelly et al. (2004, p. 7-5) suggested that
cheatgrass shortens fire intervals to less than 10 years. As discussed
under the discussion of climate change below, temperature increases may
increase the competitive advantage of cheatgrass in higher elevation
areas where its current distribution is limited (Miller et al. in
press, p. 47). Decreased summer precipitation reduces the competitive
advantage of summer perennial grasses, reduces sagebrush cover, and
subsequently increases the likelihood of cheatgrass invasion (Bradley
2009, pp. 202-204; Prevey et al. 2009, p. 11). This could increase the
susceptibility of sagebrush areas in Utah and Colorado to cheatgrass
invasion (Bradley 2009, p. 204).
A variety of restoration and rehabilitation techniques are used to
treat invasive plants, but they can be costly and are mostly unproven
and experimental at a large scale. In the last approximately 100 years,
no broad-scale cheatgrass eradication method has been developed.
Habitat treatments that either disturb the soil surface or deposit a
layer of litter increase cheatgrass establishment in the Gunnison Basin
when a cheatgrass seed source is present (Sokolow 2005, p. 51).
Therefore, researchers recommend using habitat treatment tools, such as
brush mowers, with caution and suggest that treated sites should be
monitored for increases in cheatgrass emergence (Sokolow 2005, p. 49).
Invasive Plants in the Gunnison Basin Population Area - Quantifying
the total amount of Gunnison sage-grouse habitat impacted by invasive
plants is difficult due to differing sampling methodologies, incomplete
sampling, inconsistencies in species sampled, and varying
interpretations of what constitutes an infestation (Miller et al., in
press, p. 19). Cheatgrass has invaded areas in Gunnison sage-grouse
range, supplanting sagebrush habitat in some areas. However, we do not
have a reliable estimate of the amount of area occupied by cheatgrass
in the range of Gunnison sage-grouse. While not ubiquitous, cheatgrass
is found at numerous locations throughout the Gunnison Basin (BLM 2009,
p. 60). Cheatgrass infestation within a particular area can range from
a small number of individuals scattered sparsely throughout a site, to
complete or near-complete understory domination of a site. Cheatgrass
has increased throughout the Gunnison Basin in the last decade and is
becoming increasingly detrimental to sagebrush community types (BLM
2009, p. 7). Currently in the Gunnison Basin, cheatgrass attains site
dominance most often along roadways; however, other highly disturbed
areas have similar cheatgrass densities. Cheatgrass is currently
present in almost every grazing allotment in Gunnison sage-grouse
occupied habitat and other invasive plant species, such as Canada
thistle, black henbane, spotted knapweed, Russian knapweed, Kochia,
bull thistle, musk thistle, oxeye daisy, yellow toadflax and field
bindweed, are found in riparian areas and roadsides
[[Page 59822]]
throughout the Gunnison Basin (BLM 2009, p. 7).
Although disturbed areas most often contain the highest cheatgrass
densities, cheatgrass can readily spread into less disturbed and even
undisturbed habitat. A strong indicator for future cheatgrass locations
is the proximity to current locations (Bradley and Mustard 2006, p.
1146) as well as summer, annual, and spring precipitation, and winter
temperature (Bradley 2009, p. 196). Although we lack the information to
make a detailed determination on the actual extent or rate of increase,
given its invasive nature, we believe cheatgrass and its negative
influence on Gunnison sage-grouse will increase in the Gunnison Basin
in the future because of potential exacerbation from climate change
interactions and the limited success of broad-scale control efforts.
Invasive Plants in All Other Population Areas - Cheatgrass is
present throughout much of the current range in the San Miguel Basin
(BLM 2005c, p. 62005d), but is most abundant in the Dry Creek Basin
group (CDOW 2005a, p. 101), which comprises 62 percent of the San
Miguel Basin population. It is present in the five Gunnison sage-grouse
subpopulations east of Dry Creek Basin although at much lower densities
and does not currently pose a serious threat to Gunnison sage-grouse
(CDOW 2005a, p. 101). Invasive species are present at low levels in the
Monticello group (San Juan County GSGWG 2005, p. 20). However, there is
no evidence that they are affecting the population. Cheatgrass
dominates 10-15 percent of the sagebrush understory in the current
range of the Pinon Mesa population (Lambeth 2005, pers comm.). It
occurs in the lower elevation areas below Pinon Mesa that were formerly
Gunnison sage-grouse range. Cheatgrass invaded two small prescribed
burns in or near occupied habitat conducted in 1989 and 1998 (BLM
2005d, p. 62005a), and continues to be a concern with new ground-
disturbing projects. Invasive plants, especially cheatgrass, occur
primarily along roads, other disturbed areas, and isolated areas of
untreated vegetation in the Crawford population. The threat of
cheatgrass may be greater to sage-grouse than all other nonnative
species combined and could be a significant limiting factor when and if
disturbance is used to improve habitat conditions, unless mitigated
(BLM 2005c, p. 6). No current estimates of the extent of weed invasion
are available (BLM 2005c, p. 82005d).
Within the Pinon Mesa Gunnison sage-grouse population area, 520 ha
(1,284 ac) of BLM lands are currently mapped with cheatgrass as the
dominant species (BLM 2009, p. 3). This is not a comprehensive
inventory of cheatgrass occurrence, as it only includes areas where
cheatgrass dominates the plant community and does not include areas
where the species is present at lower densities. Cheatgrass
distribution has not been comprehensively mapped for the Monticello-
Dove Creek population area; however, cheatgrass is beginning to be
assessed on a site-specific and project-level basis. No significant
invasive plant occurrences are currently known in the Poncha Pass
population area.
Summary of Invasive Plants
Invasive plants negatively impact Gunnison sage-grouse primarily by
reducing or eliminating native vegetation that sage-grouse require for
food and cover, resulting in habitat loss and fragmentation. Although
invasive plants, especially cheatgrass, have affected some Gunnison
sage-grouse habitat, the impacts do not currently appear to be
threatening individual populations or the species rangewide. However,
invasive plants continue to expand their range, facilitated by ground
disturbances such as fire, grazing, and human infrastructure. Climate
change will likely alter the range of individual invasive species,
increasing fragmentation and habitat loss of sagebrush communities.
Even with treatments, given the history of invasive plants on the
landscape, and our continued inability to control such species, we
anticipate invasive plants will persist and will likely continue to
spread throughout the range of the species. Therefore, invasive plants
and associated fire risk will be on the landscape for the foreseeable
future. Although currently not a significant threat to the Gunnison
sage-grouse at the species level, we anticipate invasive species to
become an increasingly significant threat to the species in the
foreseeable future, particularly when considered in conjunction with
future climate projections and potential changes in sagebrush plant
community composition and dynamics.
Pinon-Juniper Encroachment
Pinon-juniper woodlands are a native habitat type dominated by
Pinon pine (Pinus edulis) and various juniper species (Juniperus spp.)
that can encroach upon, infill, and eventually replace sagebrush
habitat. Pinon-juniper extent has increased 10-fold in the
Intermountain West since EuroAmerican settlement, causing the loss of
many bunchgrass and sagebrush-bunchgrass communities (Miller and Tausch
2001, pp. 15-16). Pinon-juniper woodlands have also been expanding
throughout portions of the range of Gunnison sage-grouse (BLM 2009, pp.
14, 17, 25). Pinon-juniper expansion has been attributed to the reduced
role of fire, the introduction of livestock grazing, increases in
global carbon dioxide concentrations, climate change, and natural
recovery from past disturbance (Miller and Rose 1999, pp. 555-556;
Miller and Tausch 2001, p. 15; Baker, in press, p. 24). In addititon,
Gambel oak invasion as a result of fire suppression also has been
identified as a potential threat to Gunnison sage-grouse (CDOW 2002, p.
139).
Similar to powerlines, trees provide perches for raptors, and as a
consequence, Gunnison sage-grouse avoid areas with Pinon-juniper
(Commons et al. 1999, p. 239). The number of male Gunnison sage-grouse
on leks in southwest Colorado doubled after Pinon-juniper removal and
mechanical treatment of mountain sagebrush and deciduous brush (Commons
et al. 1999, p. 238).
Pinon-Juniper Encroachment in All Population Areas - We have no
information indicating that the Gunnison Basin population area is
currently undergoing significant Pinon-juniper encroachment. A
significant portion of the Pinon Mesa population is undergoing Pinon-
juniper encroachment. Approximately 9 percent (1,140 ha [3,484 ac]) of
occupied habitat in the Pinon Mesa population area have Pinon-juniper
coverage, while 7 percent (4,414 ha [10,907 ac)] of vacant or unknown
and 13 percent (7,239 ha [17,888 ac]) of potential habitat (unoccupied
habitats that could be suitable for occupation of sage-grouse if
practical restoration were applied) have encroachment (BLM 2009, p.
17).
Some areas on lands managed by the BLM are known to be undergoing
Pinon-juniper invasion. However, the extent of the area affected has
not been quantified (BLM 2009, p. 74; BLM 2009, p. 9). Approximately 9
percent of the 1,300 ha (3,200 ac) of the current range in the Crawford
population is classified as dominated by Pinon-juniper (GSRSC 2005, p.
264). However, BLM (2005d, p. 8) estimates that as much as 20 percent
of the population area is occupied by Pinon-juniper. Pinon and juniper
trees have been encroaching in peripheral habitat on Sims Mesa, and to
a lesser extent on Cerro Summit, but not to the point where it is a
serious threat to the Cerro Summit-Cimarron-Sims Mesa population area
(CDOW 2009a, p. 47). Pinon and juniper trees are reported to be
encroaching throughout the current
[[Page 59823]]
range in the Monticello group, based on a comparison of historical
versus current aerial photos, but no quantification or mapping of the
encroachment has occurred (San Juan County GSWG 2005, p. 20). A
relatively recent invasion of Pinon and juniper trees between the Dove
Creek and Monticello groups appears to be contributing to their
isolation from each other (GSRSC 2005, p. 276).
Within the range of Gunnison sage-grouse, approximately 5,341 ha
(13,197 ac) of Pinon-juniper have been treated with various methods
designed to remove Pinon and juniper trees since 2005, and nearly half
of which occurred in the Pinon Mesa population (CDOW 2009c, entire).
Mechanical treatment of areas experiencing Pinon-juniper encroachment
continues to be one of the most successful and economical habitat
treatments for the benefit of Gunnison sage-grouse.
Summary of Pinon-Juniper Encroachment
Most Gunnison sage-grouse population areas are experiencing low to
moderate levels of Pinon-juniper encroachment; however, Pinon-juniper
encroachment in the Pinon Mesa population has been significant. The
encroachment of Pinon-juniper into sagebrush habitats contributes to
the fragmentation of Gunnison sage-grouse habitat. However, Pinon-
juniper treatments, particularly when completed in the early stages of
encroachment when the sagebrush and forb understory is still intact,
have the potential to provide an immediate benefit to sage-grouse.
Approximately 5,341 ha (13,197 ac) of Pinon-juniper encroachment within
the range of Gunnison sage-grouse has been treated. We expect Pinon-
juniper encroachment and corresponding treatment efforts to continue
into the foreseeable future, which we consider to be indefinite for
this threat. Although Pinon-juniper encroachment is contributing to
habitat fragmentation in a limited area, the level of encroachment is
not sufficient to pose a significant threat to Gunnison sage-grouse at
a population or rangewide level either now or in the foreseeable
future. Pinon-juniper encroachment may become an increasingly
significant threat to the Gunnison sage-grouse if mechanical treatment
of areas experiencing Pinon-juniper encroachment declines, and if
suitable habitat continues to be lost due to other threats such as
residential and associated infrastructure development.
Domestic Grazing and Wild Ungulate Herbivory
At least 87 percent of occupied Gunnison sage-grouse habitat on
Federal lands is currently grazed by domestic livestock (USFWS 2010c,
entire). We lack information on the proportion of Gunnison sage-grouse
habitat on private lands that is currently grazed. Excessive grazing by
domestic livestock during the late 1800s and early 1900s, along with
severe drought, significantly impacted sagebrush ecosystems (Knick et
al. 2003, p. 616). Although current livestock stocking rates in the
range of Gunnison sage-grouse are substantially lower than historical
levels (Laycock et al. 1996, p. 3), long-term effects from this
overgrazing, including changes in plant communities and soils, persist
today (Knick et al. 2003, p.116).
Although livestock grazing and associated land treatments have
likely altered plant composition, increased topsoil loss, and increased
spread of exotic plants, the impacts on Gunnison sage-grouse are not
clear. Few studies have directly addressed the effect of livestock
grazing on sage-grouse (Beck and Mitchell 2000, pp. 998-1000; Wamboldt
et al. 2002, p. 7; Crawford et al. 2004, p. 11), and little direct
experimental evidence links grazing practices to Gunnison sage-grouse
population levels (Braun 1987, pp. 136-137, Connelly and Braun 1997, p.
7-9). Rowland (2004, p. 17-18) conducted a literature review and found
no experimental research that demonstrates grazing alone is responsible
for reduction in sage-grouse numbers.
Despite the obvious impacts of grazing on plant communities within
the range of the species, the GSRSC (2005, p. 114) could not find a
direct correlation between historic grazing and reduced Gunnison sage-
grouse numbers. While implications on population-level impacts from
grazing can be made based on impacts of grazing on individuals, no
studies have documented (positively or negatively) the actual impacts
of grazing at the population level.
Sage-grouse need significant grass and shrub cover for protection
from predators, particularly during nesting season, and females will
preferentially choose nesting sites based on these qualities (Hagen et
al. 2007, p. 46). In particular, nest success in Gunnison sage-grouse
habitat is related to greater grass and forb heights and shrub density
(Young 1994, p. 38). The reduction of grass heights due to livestock
grazing in sage-grouse nesting and brood-rearing areas has been shown
to negatively affect nesting success when cover is reduced below the 18
cm (7 in.) needed for predator avoidance (Gregg et al. 1994, p. 165).
Based on measurements of cattle foraging rates on bunchgrasses both
between and under sagebrush canopies, the probability of foraging on
under-canopy bunchgrasses depends on sagebrush size and shape and,
consequently, the effects of grazing on nesting habitats might be site
specific (France et al. 2008, pp. 392-393).
Several authors have noted that grazing by livestock could reduce
the suitability of breeding and brood-rearing habitat, negatively
affecting sage-grouse populations (Braun 1987, p. 137; Dobkin 1995, p.
18; Connelly and Braun 1997, p. 231; Beck and Mitchell 2000, pp. 998-
1000). Domestic livestock grazing reduces water infiltration rates and
the cover of herbaceous plants and litter, compacts the soil, and
increases soil erosion (Braun 1998, p. 147; Dobkin et al. 1998, p.
213). These impacts change the proportion of shrub, grass, and forb
components in the affected area, and facilitate invasion of exotic
plant species that do not provide suitable habitat for sage-grouse
(Mack and Thompson 1982, p. 761; Miller and Eddleman 2000, p. 19; Knick
et al., in press, p. 41).
Livestock may compete directly with sage-grouse for rangeland
resources. Cattle are grazers, feeding mostly on grasses, but they will
make seasonal use of forbs and shrub species like sagebrush (Vallentine
1990, p. 226), a primary source of nutrition for sage-grouse. A sage-
grouse hen's nutritional condition affects nest initiation rate, clutch
size, and subsequent reproductive success (Barnett and Crawford 1994,
p. 117; Coggins 1998, p. 30). Other effects of direct competition
between livestock and sage-grouse depend on condition of the habitat
and the grazing practices. Thus, the effects vary across the range of
Gunnison sage-grouse. For example, poor livestock management in mesic
sites results in a reduction of forbs and grasses available to sage-
grouse chicks, thereby affecting chick survival (Aldridge and Brigham
2003, p. 30). Chick survival is one of the most important factors in
maintaining Gunnison sage-grouse population viability (GSRSC 2005, p.
173).
Livestock can trample sage-grouse and its habitat. Although the
effect of trampling at a population level is unknown, outright nest
destruction has been documented, and the presence of livestock can
cause sage-grouse to abandon their nests (Rasmussen and Griner 1938, p.
863; Patterson 1952, p. 111; Call and Maser 1985, p. 17; Holloran and
Anderson 2003, p. 309; Coates 2007, p. 28). Coates (2007, p. 28)
documented nest abandonment
[[Page 59824]]
following partial nest depredation by a cow. In general, all recorded
encounters between livestock and grouse nests resulted in hens flushing
from nests, which could expose the eggs to predation. Visual predators
like ravens likely use hen movements to locate sage-grouse nests
(Coates 2007, p. 33). Livestock also may trample sagebrush seedlings,
thereby removing a source of future sage-grouse food and cover
(Connelly et al. 2004, pp. 7-31). Trampling of soil by livestock can
reduce or eliminate biological soil crusts making these areas
susceptible to cheatgrass invasion (Mack 1981, pp. 148-149; Young and
Allen 1997, p. 531).
Livestock grazing may have positive effects on sage-grouse under
some habitat conditions. Evans (1986, p. 67) found that sage-grouse
used grazed meadows significantly more during late summer than ungrazed
meadows because grazing had stimulated the regrowth of forbs. Greater
sage-grouse sought out and used openings in meadows created by cattle
grazing in northern Nevada (Klebenow 1981, p. 121). Also, both sheep
and goats have been used to control invasive weeds (Mosley 1996 in
Connelly et al. 2004, pp. 7-49; Merritt et al. 2001, p. 4; Olsen and
Wallander 2001, p. 30) and woody plant encroachment (Riggs and Urness
1989, p. 358) in sage-grouse habitat.
Sagebrush plant communities are not adapted to domestic grazing
disturbance. Grazing changed the functioning of systems into less
resilient, and in some cases, altered communities (Knick et al., in
press, p. 39). The ability to restore or rehabilitate areas depends on
the condition of the area relative to the ability of a site to support
a specific plant community (Knick et al., in press, p. 39). For
example, if an area has a balanced mix of shrubs and native understory
vegetation, a change in grazing management can restore the habitat to
its potential historic species composition (Pyke, in press, p. 11).
Wambolt and Payne (1986, p. 318) found that rest from grazing had a
better perennial grass response than other treatments. Active
restoration would be required where native understory vegetation is
much reduced (Pyke, in press, p. 15). But, if an area has soil loss or
invasive species, returning the site to the native historical plant
community may be impossible (Daubenmire 1970, p. 82; Knick et al., in
press, p. 39; Pyke, in press, p. 17). Aldridge et al. (2008, p. 990)
did not find any relationship between sage-grouse persistence and
livestock densities. However, the authors noted that livestock numbers
do not necessarily correlate with range condition. They concluded that
the intensity, duration, and distribution of livestock grazing are more
influential on rangeland condition than the livestock density values
used in their modeling efforts (Aldridge et al. 2008, p. 990).
Currently, there is little direct evidence linking grazing practices to
population levels of Gunnison or greater sage-grouse. Although grazing
has not been examined at large spatial scales, as discussed above, we
do know that grazing can have negative impacts to individuals, nests,
breeding productivity, and sagebrush and, consequently, to sage-grouse
at local scales.
Public Lands Grazing in the Gunnison Basin Population Area - Our
analysis of grazing is focused on BLM lands because nearly all of the
information available to us regarding current grazing management within
the range of Gunnison sage-grouse was provided by the BLM. However,
this information is pertinent to over 40 percent of the land area
currently occupied by Gunnison sage-grouse. A summary of domestic
livestock grazing management on BLM and USFS lands in occupied Gunnison
sage-grouse habitat is provided in Table 3. The BLM manages
approximately 122,376 ha (301,267 ac), or 51 percent of the area
currently occupied by Gunnison sage-grouse in the Gunnison Basin, and
approximately 98 percent of this area is actively grazed. The USFS
manages approximately 34,544 ha (85,361 ac) or 14 percent of the
occupied portion of the Gunnison Basin population area. In 2009, within
the occupied range in the Gunnison Basin population, 13 of 62 (21
percent) active BLM grazing allotments and 3 of 35 (9 percent) of USFS
grazing allotments had Gunnison sage-grouse habitat objectives
incorporated into the allotment management plans or Records of Decision
for permit renewals (USFWS 2010c, pp. 1-2). Habitat objectives for
Gunnison sage-grouse within allotment management plans were designed
such that they provide good habitat for the species when allotments are
managed in accordance with the objectives. In 2009, 57 percent of the
area of occupied habitat in active BLM grazing allotments (45 percent
of the entire Gunnison Basin population area) had a recently completed
land health assessment (LHA), and 94 percent of the area in occupied
habitat in active allotments was deemed by the BLM as not meeting LHA
objectives specific to Gunnison sage-grouse. The remainder of the LHA-
monitored allotments were deemed to be meeting objectives or as
``unknown''. LHAs are assessments of the on-the-ground condition and
represent the best available information on the status of the habitat.
We are uncertain of habitat conditions on the remaining 55 percent of
BLM lands in the Gunnison Basin. Based on the assumption that the same
proportion of these lands are also not meeting LHA objectives results
in an estimate of 94 percent of BLM lands in the Gunnison Basin not
meeting LHA objectives specific to Gunnison sage-grouse habitat. This
analysis indicates that, without taking into account habitat conditions
on private lands and other Federal and State lands, up to 48 percent of
the entire Gunnison Basin population area is not providing optimal
habitat conditions for Gunnison sage-grouse.
The fact that most grazing allotments are not meeting LHA
objectives indicates that grazing is a factor that is likely
contributing to Gunnison sage-grouse habitat degradation. In addition,
grazing has negatively impacted several Gunnison sage grouse treatments
(projects aimed at improving habitat condition) in the Gunnison Basin
(BLM 2009, p. 34). Although these areas are generally rested for 2
years after treatment, several have been heavily used by cattle shortly
after the treatment, and the effectiveness of the treatments decreased
(BLM 2009, p. 34) and reduced the potential benefits of the treatments.
[[Page 59825]]
Table 3. Summary of domestic livestock grazing management on BLM and USFS lands in occupied habitat for each of the Gunnison sage-grouse populations
(from USFWS\a\ 2010c, compilation of data provided by BLM\b\ and USFS\c\).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Percent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Assessed BLM
Number of Active USFS Number of Active BLM Active Allotments BLM Allotments Allotments
Population Allotments Allotments with GUSG\d\ with Completed Meeting LHA
Objectives LHA\e\ Objectives
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gunnison 34 62 21 66 22
--------------------------------------------------------------------------------------------------------------------------------------------------------
San Miguel Basin no data 13 0 77 40
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello-Dove Creek: ..................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dove Creek n/a 3 0 0 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello n/a\f\ 6 100 83 80
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pi[ntilde]on Mesa no data 15 53 27 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cerro Summit-Cimarron-Sims Mesa n/a\f\ 10 10 50 40
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crawford\g\ n/a\f\ 7 71 100 86
--------------------------------------------------------------------------------------------------------------------------------------------------------
Poncha Pass no data 8 13 100 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rangewide Averages 34 63 59
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\United States Fish and Wildlife Service
\b\Bureau of Land Management
\c\United States Forest Service
\d\Gunnison sage-grouse
\e\Land Health Assessments
\f\No United States Forest Service Land in occupied habitat in this population area.
\f\Includes allotments on National Park Service lands but managed by the Bureau of Land Management.
Public Lands Grazing in All Other Population Areas - The BLM
manages approximately 36 percent of the area currently occupied by
Gunnison sage-grouse in the San Miguel Basin, and approximately 79
percent of this area is actively grazed. Within the occupied range in
the San Miguel population, no active BLM grazing allotments have
Gunnison sage-grouse habitat objectives incorporated into the allotment
management plans or Records of Decision for permit renewals (USFWS
2010c, p. 9). In 2009, 10 of 15 (77 percent) active allotments had LHAs
completed in the last 15 years; 4 of 10 allotments (40 percent) were
deemed by the BLM to meet LHA objectives. Gunnison sage-grouse habitat
within the 60 percent of allotments not meeting LHA objectives and the
5 allotments with no LHAs completed are likely being adversely impacted
by grazing. Therefore, it appears that grazing in a large portion of
this population area is a factor that is likely contributing to
Gunnison sage-grouse habitat degradation.
The BLM manages 11 percent of the occupied habitat in the Dove
Creek group, and 41 percent of this area is actively grazed. Within the
occupied range in the Dove Creek group of the Monticello-Dove Creek
population, no active BLM grazing allotments have Gunnison sage-grouse
habitat objectives incorporated into the allotment management plans or
Records of Decision for permit renewals (USFWS 2010c, p. 3). In 2009,
no active allotments in occupied habitat had completed LHAs. Gunnison
sage-grouse are not explicitly considered in grazing management
planning, and the lack of habitat data limits our ability to determine
the impact to the habitat on public lands.
The BLM manages on 4 percent of the occupied habitat in the
Monticello group, and 83 percent of this area is grazed. Within the
occupied range in the Monticello group, 6 of 6 active BLM grazing
allotments have Gunnison sage-grouse habitat objectives incorporated
into the allotment management plans or Records of Decision for permit
renewals (USFWS 2010c, p. 6). In 2009, 88 percent of the area of
occupied habitat in active allotments had a recently completed LHA.
Approximately 60 percent of the area in occupied habitat in active
allotments were deemed by the BLM to meet LHA objectives. This
information suggests that grazing the majority of lands managed by the
BLM is not likely significantly contributing to Gunnison sage-grouse
habitat degradation in the Monticello population group.
The BLM manages 28 percent of occupied habitat in the Pinon Mesa
population area, and approximately 97 percent of this area is grazed.
Over 50 percent of occupied habitat in this population area is
privately owned and, while grazing certainly occurs on these lands, we
have no information on its extent. Within the occupied range in the
Pinon Mesa population, 8 of 15 (53 percent) active BLM grazing
allotments have Gunnison sage-grouse habitat objectives incorporated
into the allotment management plans or Records of Decision for permit
renewals (USFWS 2010c, p. 5). In 2009, 23 percent of the area of
occupied Gunnison sage-grouse habitat in active allotments in the Pinon
Mesa population area had LHAs completed in the last 15 years, and all
of these were deemed by the BLM to meet LHA objectives. Therefore, for
the portion of the Pinon Mesa population area for which we have
information, it appears that grazing is not likely significantly
contributing to Gunnison sage-grouse habitat degradation.
The BLM manages on 13 percent of the occupied habitat in the Cerro
Summit-Cimarron-Sims Mesa population area, and 83 percent of this area
is grazed. Within the occupied
[[Page 59826]]
range in the Cerro Summit-Cimarron-Sims Mesa population, 1 of 10 (10
percent) active BLM grazing allotments have Gunnison sage-grouse
habitat objectives incorporated into the allotment management plans or
Records of Decision for permit renewals (USFWS 2010c, p. 7). In 2009, 5
of the 10 active allotments had LHAs completed in the last 15 years and
3 (60 percent) of these were deemed by the BLM as not meeting LHA
objectives. Therefore, for the small portion of the Cerro Summit-
Cimarron-Sims Mesa population area for which we have information, it
appears that grazing is a factor that is likely contributing to some
Gunnison sage-grouse habitat degradation.
Lands administered by the BLM and NPS comprise over 75 percent of
occupied habitat in the Crawford population, and 96 percent of this
area is actively grazed. Grazing allotments on NPS lands in this area
are administered by the BLM. Within occupied range in the Crawford
population, 1 of 7 (14 percent) active BLM grazing allotments have
Gunnison sage-grouse habitat objectives incorporated into the allotment
management plans or Records of Decision for permit renewals (USFWS
2010c, p. 8). In 2009, all of the active allotments had LHAs completed
in the last 15 years, and 86 percent were deemed by the BLM to meet LHA
objectives. Seasonal forage utilization levels were below 30 percent in
most Crawford Area allotments, although a small number of allotments
had nearly 50 percent utilization (BLM 2009x, p. 68). Based on this
information, it appears that grazing is not likely significantly
contributing to Gunnison sage-grouse habitat degradation in the
majority of the Crawford population area.
The BLM manages nearly half of occupied habitat in the Poncha Pass
population area, and approximately 98 percent of this area is actively
grazed. Within the occupied range in the Poncha Pass population, 1 of 8
(13 percent) active BLM grazing allotments have Gunnison sage-grouse
habitat objectives incorporated into the allotment management plans or
Records of Decision for permit renewals (USFWS 2010c, p. 4). In 2009,
all active allotments in occupied habitat had completed LHAs, and all
were meeting LHA objectives. Based on this information it appears that
grazing is not likely significantly contributing to Gunnison sage-
grouse habitat degradation in the majority of the Poncha Pass
population area.
Non-federal Lands Grazing in All Population Areas -Livestock
grazing on private and other non-federal lands, where present, has the
potential to impact Gunnison sage-grouse, but we lack sufficient
information to make an assessment. Table 1 summarizes the percentage of
land area potentially available to grazing within each of the
populations.
As discussed earlier, some private lands are enrolled in the CRP
program and provide some benefits to Gunnison sage-grouse. The CRP land
in the Monticello group has provided a considerable amount of brood-
rearing habitat because of its forb component. Grazing of CRP land in
Utah occurred in 2002 under emergency Farm Bill provisions due to
drought and removed at least some of the grass and forb habitat
component thus likely negatively affecting Gunnison sage-grouse chick
survival. Radio-collared males and non-brood-rearing females exhibited
temporary avoidance of grazed fields during and after grazing (Lupis et
al. 2006, pp. 959-960), although one hen with a brood continued to use
a grazed CRP field. This indicates that when CRP lands are grazed,
negative impacts to their habitat and behavior may result. Since we
have very little information on the status of Gunnison sage-grouse
habitat on non-federal lands, we cannot assess whether the impacts that
are occurring rise to the level of being a threat.
Wild Ungulate Herbivory in All Population Areas - Overgrazing by
deer and elk may cause local degradation of habitats by removal of
forage and residual hiding and nesting cover. Hobbs et al. (1996, pp.
210-213) documented a decline in available perennial grasses as elk
densities increased. Such grazing could negatively impact nesting cover
for sage-grouse. The winter range of deer and elk overlaps the year-
round range of the Gunnison sage-grouse. Excessive but localized deer
and elk grazing has been documented in the Gunnison Basin (BLM 2005a,
pp. 17-18; Jones 2005, pers. comm.).
Grazing by deer and elk occurs in all Gunnison sage-grouse
population areas. Although we have no information indicating that
competition for resources is limiting Gunnison sage-grouse in the
Gunnison Basin, BLM observed that certain mountain shrubs were being
browsed heavily by wild ungulates (BLM 2009, p. 34). Subsequent results
of monitoring in mountain shrub communities indicated that drought and
big game were having large impacts on the survivability and size of
mountain mahogany (Cercocarpus utahensis), bitterbrush (Purshia
tridentata), and serviceberry (Amelanchier alnifolia) in the Gunnison
Basin (Jupuntich et al. 2010, pp. 7-9). The authors raised concerns
that observed reductions in shrub size and vigor will reduce drifting
snow accumulation, resulting in decreased moisture availability to
grasses and forbs during the spring melt. Reduced grass and forb growth
could negatively impact Gunnison sage-grouse nesting and early brood-
rearing habitat.
Grazing Summary
Livestock management and domestic grazing have the potential to
seriously degrade Gunnison sage-grouse habitat. Grazing can adversely
impact nesting and brood-rearing habitat by decreasing vegetation
available for concealment from predators. Grazing also has been shown
to compact soils, decrease herbaceous abundance, increase erosion, and
increase the probability of invasion of exotic plant species.
The impacts of livestock operations on Gunnison sage-grouse depend
upon stocking levels and season of use. We recognize that not all
livestock grazing result in habitat degradation and many livestock
operations within the range of Gunnison sage-grouse are employing
innovative grazing strategies and conservation actions (Gunnison County
Stockgrowers 2009, entire). However, available information suggests
that LHA objectives specific to Gunnison sage-grouse are not being met
on more than 50 percent of BLM-managed occupied Gunnison sage-grouse
habitat in the Gunnison Basin, San Miguel Basin, and the Cerro Summit-
Cimarron-Sims Mesa population areas. Cumulatively, the BLM-managed
portion of these populations constitutes approximately 33 percent of
the entire range of the species. Reduced habitat quality, as reflected
in unmet LHA objectives is likely to negatively impact Gunnison sage-
grouse, particularly nesting and early brood-rearing habitat, and chick
survival is one of the most important factors in maintaining Gunnison
sage-grouse population viability (GSRSC 2005, p. 173).
We know that grazing can have negative impacts to sagebrush and
consequently to Gunnison sage-grouse at local scales. Available data
indicates that impacts to sagebrush are occurring on a significant
portion of the range of the species. Given the widespread nature of
grazing within the range of Gunnison sage-grouse, the potential for
population-level impacts is highly likely. Further, we expect grazing
to persist throughout the range of Gunnison sage-grouse for the
foreseeable future. Effects of domestic livestock grazing are likely
being exacerbated by intense browsing of
[[Page 59827]]
woody species by wild ungulates in portions of the Gunnison Basin. We
conclude that habitat degradation that can result from improper grazing
is a significant threat to Gunnison sage-grouse now and in the
foreseeable future.
Nonrenewable Energy Development
Energy development on Federal (BLM and USFS) lands is regulated by
the BLM and can contain conservation measures for wildlife species (see
Factor D for a more thorough discussion). The BLM (1999, p. 1)
classified the area encompassing all Gunnison sage-grouse habitat for
its gas and oil potential. Three of the populations have areas with
high (San Miguel Basin, Monticello group) or medium (Crawford) oil and
gas potential. San Miguel County, where much oil and gas activity has
occurred in the last few years, ranked 9 out of 39 in Colorado counties
producing natural gas in 2009 (Colorado Oil and Gas Conservation
Commission 2010, p. 1) and 29 of 39 in oil production in 2009 (Colorado
Oil and Gas Conservation commission 2010, p. 2).
Energy development impacts sage-grouse and sagebrush habitats
through direct habitat loss from well pad construction, seismic
surveys, roads, powerlines and pipeline corridors, and indirectly from
noise, gaseous emissions, changes in water availability and quality,
and human presence. The interaction and intensity of effects could
cumulatively or individually lead to habitat fragmentation (Suter 1978,
pp. 6-13; Aldridge 1998, p. 12; Braun 1998, pp. 144-148; Aldridge and
Brigham 2003, p. 31; Knick et al. 2003, pp. 612, 619; Lyon and Anderson
2003, pp. 489-490; Connelly et al. 2004, pp. 7-40 to 7-41; Holloran
2005, pp. 56-57; Holloran 2007 et al.,, pp. 18-19; Aldridge and Boyce
2007, pp. 521-522; Walker et al. 2007a, pp. 2652-2653; Zou et al. 2006,
pp. 1039-1040; Doherty et al. 2008, p. 193; Leu and Hanser, in press,
p. 28). Increased human presence resulting from oil and gas development
can impact sage-grouse either through avoidance of suitable habitat, or
disruption of breeding activities (Braun et al. 2002, pp. 4-5; Aldridge
and Brigham 2003, pp. 30-31; Aldridge and Boyce 2007, p. 518; Doherty
et al. 2008, p. 194).
The development of oil and gas resources requires surveys for
economically recoverable reserves, construction of well pads and access
roads, subsequent drilling and extraction, and transport of oil and
gas, typically through pipelines. Ancillary facilities can include
compressor stations, pumping stations, electrical generators and
powerlines (Connelly et al. 2004, p. 7-39; BLM 2007, p. 2-110). Surveys
for recoverable resources occur primarily through noisy seismic
exploration activities. These surveys can result in the crushing of
vegetation. Well pads vary in size from 0.10 ha (0.25 ac) for coal-bed
natural gas wells in areas of level topography to greater than 7 ha
(17.3 ac) for deep gas wells and multiwell pads (Connelly et al. 2004,
pp. 7-39; BLM 2007, pp. 2-123). Pads for compressor stations require 5-
7 ha (12.4-17.3 ac) (Connelly et al. 2004, pp. 7-39).
The amount of direct habitat loss within an area is ultimately
determined by well densities and the associated loss from ancillary
facilities. Roads associated with oil and gas development were
suggested to be the primary impact to greater sage-grouse due to their
persistence and continued use even after drilling and production ceased
(Lyon and Anderson 2003, p. 489). Declines in male greater sage-grouse
lek attendance were reported within 3 km (1.9 mi) of a well or haul
road with a traffic volume exceeding one vehicle per day (Holloran
2005, p. 40). Because of reasons discussed previously, we believe the
effects to Gunnison sage-grouse are similar to those observed in
greater sage-grouse. Sage-grouse also may be at increased risk for
collision with vehicles simply due to the increased traffic associated
with oil and gas activities (Aldridge 1998, p. 14; BLM 2003, p. 4-222).
Habitat fragmentation resulting from oil and gas development
infrastructure, including access roads, may have greater effects on
sage-grouse than the associated direct habitat losses. Energy
development and associated infrastructure works cumulatively with other
human activity or development to decrease available habitat and
increase fragmentation. Greater sage-grouse leks had the lowest
probability of persisting (40-50 percent) in a landscape with less than
30 percent sagebrush within 6.4 km (4 mi) of the lek (Walker et al.
2007a, p. 2652). These probabilities were even less in landscapes where
energy development also was a factor.
Nonrenewable Energy Development in All Population Areas -
Approximately 33 percent of the Gunnison Basin population area ranked
as low oil and gas potential with the remainder having no potential for
oil and gas development (GSRSC 2005, p. 130). Forty-three gas wells
occur on private lands within the occupied range of the Gunnison sage-
grouse. Of these, 27 wells occur in the San Miguel population, 8 in the
Gunnison Basin population, 6 in the Dove Creek group of the Monticello-
Dove Creek population, and 1 in each of the Crawford and Cerro Summit-
Cimarron-Sims Mesa populations (derived from Colorado Oil and Gas
Commission 2010, GIS dataset).
No federally leased lands exist within the Gunnison Basin
population area (BLM and USFS 2010). The Monticello group is in an area
of high energy potential (GSRSC 2005, p. 130); however, less than two
percent of the population area contains Federal leases upon which
production is occurring, and no producing leases occur in currently
occupied Gunnison sage-grouse habitat (BLM Geocommunicator, 2010). No
oil and gas wells or authorized Federal leases are within the Pinon
Mesa population area (BLM 2009, p. 1; BLM Geocommunicator), and no
potential for oil or gas exists in this area except for a small area on
the eastern edge of the largest habitat block (BLM 1999, p. 1; GSRSC
2005, p. 130). The Crawford population is in an area with high to
medium potential for oil and gas development (GSRSC 2005, p. 130). A
single authorized Federal lease (BLM Geocommunicator) constitutes less
than 1 percent of the Crawford population area.
Energy development is occurring primarily in the San Miguel Basin
Gunnison sage-grouse population area in Colorado. The entire San Miguel
Basin population area has high potential for oil and gas development
(GSRSC 2005, p. 130). Approximately 13 percent of occupied habitat area
within the San Miguel Basin population has authorized Federal leases;
of that, production is occurring on approximately 5 percent (BLM
National Integrated Lands System (NILS) p. 1). Currently, 25 gas wells
are active within occupied habitat of the San Miguel Basin, and an
additional 18 active wells occur immediately adjacent to occupied
habitat (San Miguel County 2009, p. 1). All of these wells are in or
near the Dry Creek group. The exact locations of any future drill sites
are not known, but because the area is small, they will likely lie
within 3 km (2 mi) of one of only three leks in this group (CDOW 2005a,
p. 108).
Although the BLM has deferred (temporarily withheld from recent
lease sales) oil and gas parcels nominated for leasing in occupied
Gunnison sage-grouse habitat in Colorado since 2005, we expect energy
development in the San Miguel Basin on public and private lands to
continue over the next 20 years based on the length of development and
production projects described in existing project and management plans.
Current impacts from gas development may exacerbate Gunnison sage-
grouse imperilment in the Dry Creek group
[[Page 59828]]
because this area contains some of the poorest habitat and smallest
grouse populations within the San Miguel population (San Miguel Basin
Gunnison sage-grouse Working Group, 2009 pp. 28 and 36).
The San Miguel Basin population area is the only area within the
Gunnison sage-grouse range with a high potential for oil and gas
development. However, the immediate threat to Gunnison sage-grouse is
limited because the BLM is deferring leases until they can be
considered within Land Use Plans (BLM 2009, p. 78). We anticipate
energy development activities to continue over the next 20 years.
However, because nonrenewable energy activities are limited to a small
portion of the range, primarily the Dry Creek portion of the San Miguel
Basin population of Gunnison sage-grouse, we do not consider
nonrenewable energy development to be a significant threat to the
species.
Renewable Energy - Geothermal, Solar, Wind
Geothermal energy production is similar to oil and gas development
in that it requires surface exploration, exploratory drilling, field
development, and plant construction and operation. Wells are drilled to
access the thermal source and could take from 3 weeks to 2 months of
drilling occurring on a continuous basis (Suter 1978, p. 3), which may
cause disturbance to sage-grouse. The ultimate number of wells, and
therefore potential loss of habitat, depends on the thermal output of
the source and expected production of the plant (Suter 1978, p. 3).
Pipelines are needed to carry steam or superheated liquids to the
generating plant, which is similar in size to a coal- or gas-fired
plant, resulting in further habitat destruction and indirect
disturbance. Direct habitat loss occurs from well pads, structures,
roads, pipelines and transmission lines, and impacts would be similar
to those described previously for oil and gas development. The
development of geothermal energy requires intensive human activity
during field development and operation. Geothermal development could
cause toxic gas release. The type and effect of these gases depends on
the geological formation in which drilling occurs (Suter 1978, pp. 7-
9). The amount of water necessary for drilling and condenser cooling
may be high. Local water depletions may be a concern if such depletions
result in the loss of brood-rearing habitat.
Renewable Energy in the Gunnison Basin Population Area -
Approximately 87 percent of the occupied range of Gunnison sage-grouse
is within a region of known geothermal potential (BLM Geocommunicator
2010, p. 1). We were unable to find any information on the presence of
active geothermal energy generation facilities; however, we are aware
of three current applications for geothermal leases within the range of
Gunnison sage-grouse. All of the applications are located in the same
general vicinity on private, BLM, USFS, and Colorado State Land Board
lands near Tomichi Dome and Waunita Hot Springs in southeastern
Gunnison County. The cumulative area of the geothermal lease
application parcels is approximately 4,061 ha (10,035 ac), of which
approximately 3,802 ha (9,395 ac) is occupied Gunnison sage-grouse
habitat, or approximately 2 percent of the Gunnison Basin population
area. One active lek and two inactive leks are located within the lease
application parcels. In addition, six active leks and four inactive
leks are within 6.4 km (4 mi) of the lease application parcels
indicating that over 80 percent of Gunnison sage-grouse seasonal use
occurs within the area associated with these leks (GSRSC 2005, p. J-4).
There are 74 active leks in the Gunnison Basin population, so
approximately 10 percent of active leks may be affected. A significant
amount of high-quality Gunnison sage-grouse nesting habitat exists on
and near the lease application parcels (Aldridge et al. 2010, in
press). This potential geothermal development would likely negatively
impact Gunnison sage-grouse through the direct loss of habitat and the
functional loss of habitat resulting from increased human activity in
the area; however, we cannot determine the potential extent of the
impact at this time because the size and location of potential
geothermal energy generation infrastructure and potential resource
protection conditions are unknown at this time.
Renewable Energy in All Other Population Areas - We could find no
information on the presence of existing, pending, or authorized wind
energy sites, solar energy sites, nor any solar energy study areas
within the range of Gunnison sage-grouse. A 388-ha (960-ac) wind energy
generation facility is authorized on BLM lands in San Juan County, UT.
However, the authorized facility is approximately 12.9 km (8 mi) from
the nearest lek in the Monticello group of the Monticello-Dove Creek
Gunnison sage-grouse population. Therefore, we conclude that wind and
solar energy development are not a significant threat to the Gunnison
sage-grouse and we do not expect these activities to become significant
threats in the foreseeable future.
The only existing or proposed renewable energy project we are aware
of is located in the Gunnison Basin. A portion of the Gunnison Basin
population will likely be adversely affected by proposed geothermal
development if it is implemented. Because of the current preliminary
status of geothermal development, we lack the specific project details
to evaluate the extent to which this activity will affect the
population's overall viability. Therefore, we do not consider renewable
energy development to be a threat to the Gunnison sage-grouse at this
time. Geothermal energy development could become a future threat to the
species, but we do not know to what extent future geothermal energy
development will occur. Future geothermal development could be
encouraged by a new Colorado State law, signed April 30, 2010, that
will facilitate streamlining of the State permitting process.
Summary of Nonrenewable and Renewable Energy Development
The San Miguel Basin population area is the only area within the
Gunnison sage-grouse range with a high potential for oil and gas
development. However, the immediate threat to Gunnison sage-grouse is
limited because the BLM is temporarily deferring leases until they can
be considered within Land Use Plans. We anticipate energy development
activities to continue over the next 20 years. Although we recognize
that the Dry Creek portion of the San Miguel Basin population may be
impacted by nonrenewable energy development, we do not consider
nonrenewable energy development to be a significant threat to the
species now or in the foreseeable future, because its current and
anticipated extent is limited throughout the range of Gunnison sage-
grouse. Similarly, we do not consider renewable energy development to
be a significant threat to Gunnison sage-grouse now or in the
foreseeable future. However, geothermal energy development could
increase in the future and could (depending on the level of development
and minimization and mitigation measures) substantially influence the
overall long-term viability of the Gunnison Basin population.
Climate Change
According to the Intergovernmental Panel on Climate Change (IPCC),
``Warming of the climate system in recent decades is unequivocal, as is
now evident from observations of increases in global average air and
ocean
[[Page 59829]]
temperatures, widespread melting of snow and ice, and rising global sea
level'' (IPCC 2007, p. 1). Average Northern Hemisphere temperatures
during the second half of the 20th century were very likely higher than
during any other 50-year period in the last 500 years and likely the
highest in at least the past 1,300 years (IPCC 2007, p. 30). Over the
past 50 years cold days, cold nights, and frosts have become less
frequent over most land areas, and hot days and hot nights have become
more frequent. Heat waves have become more frequent over most land
areas, and the frequency of heavy precipitation events has increased
over most areas (IPCC 2007, p. 30). For the southwestern region of the
United States, including western Colorado, warming is occurring more
rapidly than elsewhere in the country (Karl et al. 2009, p. 129).
Annual average temperature in west-central Colorado increased 3.6
[deg]C (2 [deg]F) over the past 30 years, but high variability in
annual precipitation precludes the detection of long-term trends (Ray
et al. 2008, p. 5).
Under high emission scenarios, future projections for the
southwestern United States show increased probability of drought (Karl
et al. 2009, pp. 129-134) and the number of days over 32 [deg]C (90
[deg]F) could double by the end of the century (Karl et al. 2009, p.
34). Climate models predict annual temperature increase of
approximately 2.2 [deg]C (4 [deg]F) in the southwest by 2050, with
summers warming more than winters (Ray et al. 2008, p. 29). Projections
also show declines in snowpack across the West, with the most dramatic
declines at lower elevations (below 2,500 m (8,200 ft)) (Ray et al., p.
29).
Localized climate projections are problematic for mountainous areas
because current global climate models are unable to capture this
topographic variability at local or regional scales (Ray et al. 2008,
pp. 7, 20). To obtain climate projections specific to the range of
Gunnison sage-grouse, we requested a statistically downscaled model
from the National Center for Atmospheric Research for a region covering
western Colorado. The resulting projections indicate the highest
probability scenario is that average summer (June through September)
temperature could increase by 2.8 [deg]C (5.1 [deg]F), and average
winter (October through March) temperature could increase by 2.2 [deg]C
(4.0 [deg]F) by 2050 (University Corporation for Atmospheric Research
(UCAR) 2009, pp. 1-15). Annual mean precipitation projections for
Colorado are unclear; however, multi-model averages show a shift
towards increased winter precipitation and decreased spring and summer
precipitation (Ray et al. 2008, p. 34; Karl et al. 2009, p. 30).
Similarly, the multi-model averages show the highest probability of a
five percent increase in average winter precipitation and a five
percent decrease in average spring-summer precipitation in 2050 (UCAR
2009, p. 15).
While it is unclear at this time whether or not the year 2050
predicted changes in precipitation and temperature will be of
significant magnitude to alter sagebrush plant community composition
and dynamics, we believe climate change is likely to alter fire
frequency, community assemblages, and the ability of nonnative species
to proliferate. Increasing temperature as well as changes in the timing
and amount of precipitation will alter the competitive advantage among
plant species (Miller et al. in press, p. 44), and may shift individual
species and ecosystem distributions (Bachelet et al. 2001, p. 174). For
sagebrush, spring and summer precipitation comprises the majority of
the moisture available to the species; thus, the interaction between
reduced precipitation in the spring-summer growing season and increased
summer temperatures will likely decrease growth of mountain big
sagebrush (Artemisia tridentata ssp. vaseyana). This could result in a
significant long-term reduction in the distribution of sagebrush
communities (Miller et al. in press, pp. 41-45). In the Gunnison Basin,
increased summer temperature was strongly correlated with reduced
growth of mountain big sagebrush (Poore et al. 2009, p. 558). Based on
these results and the likelihood of increased winter precipitation
falling as rain rather than snow, Poore et al. (2009, p. 559) predict
decreased growth of mountain big sagebrush, particularly at the lower
elevation limit of the species. Because Gunnison sage-grouse are
sagebrush obligates, loss of sagebrush would result in a reduction of
suitable habitat and negatively impact the species. The interaction of
climate change with other stressors likely has impacted and will impact
the sagebrush steppe ecosystem within which Gunnison sage-grouse occur.
Temperature increases may increase the competitive advantage of
cheatgrass in higher elevation areas where its current distribution is
limited (Miller et al. in press, p. 47). Decreased summer precipitation
reduces the competitive advantage of summer perennial grasses, reduces
sagebrush cover, and subsequently increases the likelihood of
cheatgrass invasion (Prevey et al. 2009, p. 11). This impact could
increase the susceptibility of areas within Gunnison sage-grouse range
to cheatgrass invasion (Bradley 2009, p. 204), which would reduce the
overall cover of native vegetation, reduce habitat quality, and
potentially decrease fire return intervals, all of which would
negatively affect the species.
Summary of Climate Change
Climate change predictions are based on models with assumptions,
and there are uncertainties regarding the magnitude of associated
climate change parameters such as the amount and timing of
precipitation and seasonal temperature changes. There is also
uncertainty as to the magnitude of effects of predicted climate
parameters on sagebrush plant community dynamics. These factors make it
difficult to predict the effects of climate change on Gunnison sage-
grouse. We recognize that climate change has the potential to alter
Gunnison sage-grouse habitat by facilitating an increase in the
distribution of cheatgrass and concurrently increase the potential for
wildfires, which would have negative effects on Gunnison sage-grouse.
However, based on the best available information on climate change
projections into the next 40 years, we do not consider climate change
to be a significant threat to the Gunnison sage-grouse at this time.
Existing data indicates that climate change has the potential to alter
changes in the distribution and extent of cheatgrass and sagebrush and
associated fire frequencies and therefore is likely to become an
increasingly important factor affecting Gunnison sage-grouse and its
habitat in the foreseeable future.
Summary of Factor A
Gunnison sage-grouse require large, contiguous areas of sagebrush
for long-term persistence, and thus are affected by factors that occur
at the landscape scale. Broad-scale characteristics within surrounding
landscapes influence habitat selection, and adult Gunnison sage-grouse
exhibit a high fidelity to all seasonal habitats, resulting in low
adaptability to habitat changes. Fragmentation of sagebrush habitats
has been cited as a primary cause of the decline of Gunnison and
greater sage-grouse populations (Patterson 1952, pp. 192-193; Connelly
and Braun 1997, p. 4; Braun 1998, p. 140; Johnson and Braun 1999, p.
78; Connelly et al. 2000a, p. 975; Miller and Eddleman 2000, p. 1;
Schroeder and Baydack 2001, p. 29; Johnsgard 2002, p. 108; Aldridge and
Brigham 2003, p. 25; Beck et al. 2003, p. 203; Pedersen et al. 2003,
pp. 23-24; Connelly et al. 2004, p. 4-15; Schroeder et al. 2004, p.
368; Leu et al. in press,
[[Page 59830]]
p. 19). Documented negative effects of fragmentation include reduced
lek persistence, lek attendance, population recruitment, yearling and
adult annual survival, female nest site selection, and nest initiation
rates, as well as the loss of leks and winter habitat (Holloran 2005,
p. 49; Aldridge and Boyce 2007, pp. 517-523; Walker et al. 2007a, pp.
2651-2652; Doherty et al. 2008, p. 194).
We examined several factors that result in habitat loss and
fragmentation. Historically, losses of sagebrush habitats occurred due
to conversion for agricultural croplands; however, this trend has
slowed or slightly reversed in recent decades. Currently, direct and
functional loss of habitat due to residential and road development in
all populations, including the largest population in the Gunnison
Basin, is the principal threat to Gunnison sage-grouse. Functional
habitat loss also contributes to habitat fragmentation as sage-grouse
avoid areas due to human activities, including noise, even when
sagebrush remains intact. The collective disturbance from human
activities around residences and roads reduces the effective habitat
around these areas, making them inhospitable to Gunnison sage-grouse.
Human populations are increasing in Colorado and throughout the range
of Gunnison sage-grouse. This trend is expected to continue at least
through 2050. The resulting habitat loss and fragmentation will
continue to negatively affect Gunnison sage-grouse and its habitat.
Other threats from human infrastructure such as fences and
powerlines may not individually threaten the Gunnison sage-grouse.
However, the cumulative presence of all these features, particularly
when considered in conjunction with residential and road development,
does constitute a significant threat to Gunnison sage-grouse as they
collectively contribute to habitat loss and fragmentation. This impact
is particularly of consequence in light of the decreases in Gunnison
sage-grouse population sizes observed in the six smallest populations.
These infrastructure components are associated with overall increases
in human populations and thus we expect them to continue to increase in
the foreseeable future.
Several issues discussed above, such as fire, invasive species, and
climate change, may not individually threaten the Gunnison sage-grouse.
However, the documented synergy among these issues result in a high
likelihood that they will threaten the species in the future. Nonnative
invasive plants, including cheatgrass and other noxious weeds, continue
to expand their range, facilitated by ground disturbances such as fire,
grazing, and human infrastructure. Invasive plants negatively impact
Gunnison sage-grouse primarily by reducing or eliminating native
vegetation that sage-grouse require for food and cover, resulting in
habitat loss (both direct and functional) and fragmentation. Cheatgrass
is present at varying levels in nearly all Gunnison sage-grouse
population areas, but there has not yet been a demonstrated change in
fire cycle in the range of Gunnison sage-grouse. However, climate
change may alter the range of invasive plants, intensifying the
proliferation of invasive plants to the point that they and their
effects on Gunnison sage-grouse habitat will likely become a threat to
the species. Even with aggressive treatments, invasive plants will
persist and will likely continue to spread throughout the range of
Gunnison sage-grouse in the foreseeable future.
Livestock management has the potential to degrade sage-grouse
habitat at local scales by causing the loss of nesting cover and
decreases in native vegetation, and by increasing the probability of
incursion of invasive plants. Given the widespread nature of grazing
within the range of Gunnison sage-grouse, the potential for population-
level impacts is highly likely. Effects of domestic livestock grazing
are likely being exacerbated by intense browsing of woody species by
wild ungulates in portions of the Gunnison Basin. We conclude that
habitat degradation that can result from improper grazing is a
significant threat to Gunnison sage-grouse now and in the foreseeable
future.
Threats identified above, particularly residential development and
associated infrastructure such as fences, roads, and powerlines, are
cumulatively causing significant habitat fragmentation that is
negatively affecting Gunnison sage-grouse. We have evaluated the best
available scientific information available on the present or threatened
destruction, modification or curtailment of the Gunnison sage-grouse's
habitat or range. Based on the current and anticipated habitat threats
identified above, and their cumulative effects as they contribute to
the overall fragmentation of Gunnison sage-grouse habitat, we have
determined that the present or threatened destruction, modification, or
curtailment of Gunnison sage-grouse habitat poses a significant threat
to the species throughout its range.
The species is being impacted by several other factors, but their
significance is not at a level that they cause the species to become
threatened or endangered in the foreseeable future. We do not consider
nonrenewable energy development to be a significant threat to the
species because its current and anticipated extent is limited
throughout the range of Gunnison sage-grouse. Similarly, we do not
consider renewable energy development to be a significant threat to the
Gunnison sage-grouse at this time. However, geothermal energy
development could increase in the future. Pinon-juniper encroachment
does not pose a significant threat to Gunnison sage-grouse at a
population or rangewide level because of its limited distribution
throughout the range of Gunnison sage-grouse and the observed
effectiveness of treatment projects.
A review of a database compiled by the CDOW that included local,
State, and Federal ongoing and proposed Gunnison sage-grouse
conservation actions (CDOW 2009c, entire) revealed a total of 224
individual conservation efforts. Of these 224 efforts, a total of 165
efforts have been completed and were focused on habitat improvement or
protection. These efforts resulted in the treatment of 9,324 ha (23,041
ac), or approximately 2.5 percent of occupied Gunnison sage-grouse
habitat. A monitoring component was included in 75 (45 percent) of
these 165 efforts, although we do not have information on the overall
effectiveness of these efforts. Given the limited collective extent of
these efforts, they do not ameliorate the effects of habitat
fragmentation at a sufficient scale range-wide to effectively reduce or
eliminate the most significant threats to the species. We recognize
ongoing and proposed conservation efforts by all entities across the
range of the Gunnison sage-grouse, and all parties should be commended
for their conservation efforts. Our review of conservation efforts
indicates that the measures identified are not adequate to address the
primary threat of habitat fragmentation at this time in a manner that
effectively reduces or eliminates the most significant contributors
(e.g., residential development) to this threat. All of the conservation
efforts are limited in size and the measures provided to us were simply
not implemented at the scale (even when considered cumulatively) that
would be required to effectively reduce the threats to the species
across its range. Although the ongoing conservation efforts are a
positive step toward the conservation of the Gunnison sage-grouse, and
some have likely reduced the severity of some threats to the species
(e.g., Pinon-juniper invasion), on the whole we find
[[Page 59831]]
that the conservation efforts in place at this time are not sufficient
to offset the degree of threat posed to the species by the present and
threatened destruction, modification, or curtailment of its habitat.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Hunting
Hunting for Gunnison sage-grouse does not currently occur. Hunting
was eliminated in the Gunnison Basin in 2000 due to concerns with
meeting Gunnison sage-grouse population objectives (CSGWG 1997, p. 66).
Hunting has not occurred in the other Colorado populations of Gunnison
sage-grouse since 1995 when the Pinon Mesa area was closed (GSRSC 2005,
p. 122). Utah has not allowed hunting of Gunnison sage-grouse since
1989 (GSRSC 2005, p. 82).
Both Colorado and Utah will only consider hunting of Gunnison sage-
grouse if populations can be sustained (GSRSC 2005, pp. 5, 8, 229). The
Gunnison Basin Plan calls for a minimum population of 500 males counted
on leks before hunting would occur again (CSGWG 1997, p. 66). The
minimum population level has been exceeded in all years since 1996,
except 2003 and 2004 (CDOW 2009d, p. 18-19). However, the sensitive
State regulatory status and potential political ramifications of
hunting the species has precluded the States from opening a hunting
season. If hunting does ever occur again, harvest will likely be
restricted to only 5 to 10 percent of the fall population, and will be
structured to limit harvest of females to the extent possible (GSRSC
2005, p. 229). However, the ability of these measures to be implemented
is in question, as adequate means to estimate fall population size have
not been developed (Reese and Connelly in press, p. 21) and limiting
female harvest may not be possible (WGFD 2004, p. 4; WGFD 2006, pp. 5,
7). Despite these questions, we believe that the low level of hunting
that could be allowed in the future would not be a significant threat
to the Gunnison sage-grouse.
One sage-grouse was known to be illegally harvested in 2001 in the
Poncha Pass population (Nehring 2010, pers. comm.), but based on the
best available information we do not believe that illegal harvest has
contributed to Gunnison sage-grouse population declines in either
Colorado or Utah. We do not anticipate hunting to be opened in the
Gunnison Basin or smaller populations for many years, if ever.
Consequently, we do not consider hunting to be a significant threat to
the species now or in the foreseeable future.
Lek Viewing
The Gunnison sage-grouse was designated as a new species in 2000
(American Ornithologists' Union 2000, pp. 847-858), which has prompted
increased interest by bird watchers to view the species on their leks
(Pfister 2010, pers. comm.). Daily human disturbances on sage-grouse
leks could cause a reduction in mating, and some reduction in total
production (Call and Maser 1985, p. 19). Human disturbance,
particularly if additive to disturbance by predators, could reduce the
time a lek is active, as well as reduce its size by lowering male
attendance (Boyko et al. 2004, in GSRSC 2005, p. 125). Smaller lek
sizes have been hypothesized to be less attractive to females, thereby
conceivably reducing the numbers of females mating. Disturbance during
the peak of mating also could result in some females not breeding
(GSRSC 2005, p. 125). Furthermore, disturbance from lek viewing might
affect nesting habitat selection by females (GSRSC 2005, p. 126), as
leks are typically close to areas in which females nest. If females
move to poorer quality habitat farther away from disturbed leks, nest
success could decline. If chronic disturbance causes sage-grouse to
move to a new lek site away from preferred and presumably higher
quality areas, both survival and nest success could decline. Whether
any or all of these have significant population effects would depend on
timing and degree of disturbance (GSRSC 2005, p. 126).
Throughout the range of Gunnison sage-grouse, public viewing of
leks is limited by a general lack of knowledge in the public of lek
locations, seasonal road closures in some areas, and difficulty in
accessing many leks. Furthermore, 52 of 109 active Gunnison sage-grouse
leks occur on private lands, which further limits access by the public.
The BLM closed a lek in the Gunnison Basin to viewing in the late 1990s
due to declining population counts, which were perceived as resulting
from recreational viewing, although no scientific studies were
conducted (BLM 2005a, p. 13; GSRSC 2005, pp. 124, 126). The Waunita lek
east of Gunnison is the only lek in Colorado designated by the CDOW for
public viewing (CDOW 2009a, p. 86). Since 1998, a comparison of male
counts on the Waunita lek versus male counts on other leks in the
Doyleville zone show that the Waunita lek's male counts generally
follow the same trend as the others (CDOW 2009d, pp. 31-32). In fact,
in 2008 and 2009 the Waunita lek increased in the number of males
counted along with three other leks, while seven leks decreased in the
Doyleville zone (CDOW 2009d, pp. 31-32). These data suggest that lek
viewing on the Waunita lek has not impacted the Gunnison sage-grouse.
Two lek-viewing tours per year are organized and led by UDWR on a
privately owned lek in the Monticello population. The lek declined in
males counted in 2009, but 2007 and 2008 had the highest counts for
several years, suggesting that lek viewing is also not impacting that
lek. Data collected by CDOW on greater sage-grouse viewing leks also
indicates that controlled lek visitation has not impacted greater sage-
grouse at the viewed leks (GSRSC 2005, p. 124).
A lek viewing protocol has been developed and has largely been
followed on the Waunita lek, likely reducing impacts to sage-grouse
using the lek (GSRSC 2005, p. 125). During 2004-2009, the percentage of
individuals or groups of people in vehicles following the Waunita lek
viewing protocol in the Gunnison Basin ranged from 71-92 percent (CDOW
2009a, p. 86, 87; Magee et al. 2009, p. 7, 10). Violations of the
protocol, such as showing up after the sage-grouse started to display
and creating noise, caused one or more sage-grouse to flush from the
lek (CDOW 2009a, pp. 86, 87). Despite the protocol violations, the
percentage of days from 2004 to 2009 that grouse were flushed by humans
was relatively low, ranging from 2.5 percent to 5.4 percent (Magee et
al. 2009, p.10). Nonetheless, the lek viewing protocol is currently
being revised to make it more stringent and to include considerations
for photography, research, and education related viewing (CDOW 2009a,
p. 86). Maintenance of this protocol should preclude lek viewing from
becoming a threat to this lek.
The CDOW and UDWR will continue to coordinate and implement lek
counts to determine population levels. We expect annual lek viewing and
lek counts to continue indefinitely. However, all leks counted will
receive lower disturbance from counters than the Waunita lek received
from public viewing, so we do not consider lek counts and viewing a
threat to the Gunnison sage-grouse now or in the foreseeable future.
Scientific Research
Gunnison sage-grouse have been the subject of scientific research
studies, some of which included the capture and handling of the
species. Most of the research has been conducted in the Gunnison Basin
population, San Miguel
[[Page 59832]]
Basin population, and Monticello portion of the Monticello-Dove Creek
population. Between zero and seven percent mortality of handled adults
or juveniles and chicks has occurred during recent Gunnison sage-grouse
studies where trapping and radio-tagging was done (Apa 2004, p. 19;
Childers 2009, p. 14; Lupis 2005, p. 26; San Miguel Basin Working Group
2009, p. A-10). Additionally, one radio-tagged hen was flushed off a
nest during subsequent monitoring and did not return after the second
day, resulting in loss of 10 eggs (Ward 2007, p. 52). The CDOW does not
believe that these losses or disturbance have any significant impacts
on the sage-grouse (CDOW 2009a, p. 29).
Some of the radio-tagged sage-grouse have been translocated from
the Gunnison Basin to other populations. Over a 5-year period (2000-
2002 and 2006-2007), 68 sage-grouse were translocated from the Gunnison
Basin to the Poncha Pass and San Miguel Basin populations (CDOW 2009a,
p. 9). These experimental translocations were conducted to determine
translocation techniques and survivorship in order to increase both
size of the receiving populations and to increase genetic diversity in
populations outside of the Gunnison Basin. However, the translocated
grouse experienced 40-50 percent mortality within the first year after
release, which is double the average annual mortality of non-
translocated sage-grouse (CDOW 2009a, p. 9). Greater sage-grouse
translocations have not appeared to fare any better. Over 7,200 greater
sage-grouse were translocated between 1933 and 1990, but only five
percent of the translocation efforts were considered to be successful
in producing sustained, resident populations at the translocation sites
(Reese and Connelly 1997, pp. 235-238, 240). More recent translocations
from 2003 to 2005 into Strawberry Valley, Utah, resulted in a 40
percent annual mortality rate (Baxter et al. 2008, p. 182). We believe
the lack of success of translocations found in greater sage-grouse is
applicable to Gunnison sage-grouse since the two species exhibit
similar behavior and life-history traits, and are managed accordingly.
Because the survival rate for translocated sage-grouse has not been
as high as desired, the CDOW started a captive-rearing program in 2009
to study whether techniques can be developed to captively rear and
release Gunnison sage-grouse and enhance their survival (CDOW 2009a,
pp. 9-12). The Gunnison Sage-grouse Rangewide Steering Committee
conducted a review of captive-rearing attempts for both greater sage-
grouse and other gallinaceous birds and concluded that survival will be
very low, unless innovative strategies are developed and tested (GSRSC
2005, pp. 181-183). However, greater sage-grouse have been captively
reared, and survival of released chicks was similar to that of wild
chicks (CDOW 2009a, p. 10). Consequently, the CDOW decided to try
captive rearing. Of 40 Gunnison sage-grouse eggs taken from the wild,
only 11 chicks (about 25 percent) survived through October 2009.
Although chick survival was low, the CDOW believes they have gained
valuable knowledge on Gunnison sage-grouse rearing techniques. As
techniques improve, the CDOW intends to develop a captive-breeding
manual (CDOW 2009a, p. 11). Although adults or juveniles have been
captured and moved out of the Gunnison Basin, as well as eggs, the
removal of the grouse only accounts for a very small percentage of the
total population of the Gunnison Basin sage-grouse population (about 1
percent).
The CDOW has a policy regarding trapping, handling, and marking
techniques approved by their Animal Use and Care Committee (San Miguel
Basin Working Group 2009, p. A-10, Childers 2009, p. 13). Evaluation of
research projects by the Animal Use and Care Committee and improvement
of trapping, handling, and marking techniques over the last several
years has resulted in fewer mortalities and injuries. In fact, in the
San Miguel Basin, researchers have handled over 200 sage-grouse with no
trapping mortalities (San Miguel Basin Working Group (SMBWG) 2009, p.
A-10). The CDOW has also drafted a sage-grouse trapping and handling
protocol, which is required training for people handling Gunnison sage-
grouse, to minimize mortality and injury of the birds (CDOW 2002, pp.
1-4 in SMBWG 2009, pp. A-22-A-25). Injury and mortality does
occasionally occur from trapping, handling, marking, and flushing off
nests. However, research-related mortality is typically below three
percent of handled birds and equates to one half of one percent or less
of annual population estimates (Apa 2004, p. 19; Childers 2009, p. 14;
Lupis 2005, p. 26; San Miguel Basin Working Group 2009, p. A-10).
Research needs may gradually dwindle over the years but annual or
occasional research is expected to occur for at least 50 years
constituting the foreseeable future for this potential threat. Short-
term disturbance effects to individuals occur as does injury and
mortality, but we do not believe these effects cause a threat to the
Gunnison sage-grouse population as a whole. Based on the available
information, we believe scientific research on Gunnison sage-grouse has
a relatively minor impact that does not rise to the level of a threat
to the species now or is it expected to do so in the foreseeable
future.
Summary of Factor B
We have no evidence suggesting that hunting, when it was legal,
resulted in overutilization of Gunnison sage-grouse. If hunting is
allowed again, future hunting may result in additive mortality due to
habitat degradation and fragmentation, despite harvest level
restrictions and management intended to limit impacts to hens.
Nonetheless, we do not expect hunting to be reinstated in the
foreseeable future. Illegal hunting has been documented only once in
Colorado and is not considered a threat to the species. Lek viewing has
not affected the Gunnison sage-grouse, and lek viewing protocols
designed to reduce disturbance have generally been followed. CDOW is
currently revising their lek viewing protocol to make it more stringent
and to include considerations for photography, research, and education-
related viewing. Mortality from scientific research is low (2 percent)
and is not considered a threat. We know of no overutilization for
commercial or educational purposes. Thus, based on the best scientific
and commercial data available, we have concluded that overutilization
for commercial, recreational, scientific, or educational purposes does
not constitute a significant threat to the Gunnison sage-grouse.
C. Disease or Predation
Disease
No research has been published about the types or pathology of
diseases in Gunnison sage-grouse. However, multiple bacterial and
parasitic diseases have been documented in greater sage-grouse
(Patterson 1952, pp. 71-72; Schroeder et al. 1999, p. 14, 27). Some
early studies have suggested that greater sage-grouse populations are
adversely affected by parasitic infections (Batterson and Morse 1948,
p. 22). However, the role of parasites or infectious diseases in
population declines of greater sage-grouse is unknown based on the few
systematic surveys conducted (Connelly et al. 2004, p. 10-3). No
parasites have been documented to cause mortality in Gunnison sage-
grouse, but the protozoan, Eimeria spp., which causes coccidiosis, has
been reported to cause
[[Page 59833]]
death in greater sage-grouse (Connelly et al. 2004, p. 10-4).
Infections tend to be localized to specific geographic areas, and no
cases of greater sage-grouse mortality resulting from coccidiosis have
been documented since the early 1960s (Connelly et al. 2004, p. 10-4).
Parasites have been implicated in greater sage-grouse mate
selection, with potentially subsequent effects on the genetic diversity
of this species (Boyce 1990, p.263; Deibert 1995, p. 38). These
relationships may be important to the long-term ecology of greater
sage-grouse, but they have not been shown to be significant to the
immediate status of populations (Connelly et al. 2004, p. 10-6).
Although diseases and parasites have been suggested to affect isolated
sage-grouse populations (Connelly et al. 2004, p. 10-3), we have no
evidence indicating that parasitic diseases are a threat to Gunnison
sage-grouse populations.
Greater sage-grouse are subject to a variety of bacterial, fungal,
and viral pathogens. The bacterium Salmonella sp. has caused a single
documented mortality in the greater sage-grouse and studies have shown
that infection rates in wild birds are low (Connelly et al. 2004, p.
10-7). The bacteria are apparently contracted through exposure to
contaminated water supplies around livestock stock tanks (Connelly et
al. 2004, p. 10-7). Other bacteria found in greater sage-grouse include
Escherichia coli, botulism (Clostridium spp.), avian tuberculosis
(Mycobacterium avium), and avian cholera (Pasteurella multocida). These
bacteria have never been identified as a cause of mortality in greater
sage-grouse and the risk of exposure and hence, population effects, is
low (Connelly et al. 2004, p. 10-7 to 10-8). We have no reason to
expect that mortality and exposure risk are different in Gunnison sage-
grouse; therefore, we do not believe these bacteria to be a threat to
the species.
West Nile virus was introduced into the northeastern United States
in 1999 and has subsequently spread across North America (Marra et al.
2004, p.394). In sagebrush habitats, West Nile virus transmission is
primarily regulated by environmental factors, including temperature,
precipitation, and anthropogenic water sources, such as stock ponds and
coal-bed methane ponds that support the mosquito vectors (Reisen et al.
2006, p. 309; Walker and Naugle in press, pp. 10-12). The virus
persists largely within a mosquito-bird-mosquito infection cycle
(McLean 2006, p. 45). However, direct bird-to-bird transmission of the
virus has been documented in several species (McLean 2006, pp. 54, 59)
including the greater sage-grouse (Walker and Naugle in press, p. 13;
Cornish 2009, pers. comm.). The frequency of direct transmission has
not been determined (McLean 2006, p. 54). Cold ambient temperatures
preclude mosquito activity and virus amplification, so transmission to
and in sage-grouse is limited to the summer (mid-May to mid-September)
(Naugle et al. 2005, p. 620; Zou et al. 2007, p. 4), with a peak in
July and August (Walker and Naugle in press, p. 10). Reduced and
delayed West Nile virus transmission in sage-grouse has occurred in
years with lower summer temperatures (Naugle et al. 2005, p. 621;
Walker et al. 2007b, p. 694). In non-sagebrush ecosystems, high
temperatures associated with drought conditions increase West Nile
virus transmission by allowing for more rapid larval mosquito
development and shorter virus incubation periods (Shaman et al. 2005,
p. 134; Walker and Naugle in press, p. 11). Additional details on the
impacts of West Nile virus on greater sage-grouse can be found in our
recent finding (75 FR 13910; March 23, 2010).
Greater sage-grouse congregate in mesic habitats in the mid-late
summer (Connelly et al. 2000, p. 971), thereby increasing their risk of
exposure to mosquitoes. If West Nile virus outbreaks coincide with
drought conditions that aggregate birds in habitat near water sources,
the risk of exposure to West Nile virus will be elevated (Walker and
Naugle in press, p. 11). Greater sage-grouse inhabiting higher
elevation sites in summer (similar to the northern portion of the
Gunnison Basin) are likely less vulnerable to contracting West Nile
virus than birds at lower elevation (similar to Dry Creek Basin of the
San Miguel population) as ambient temperatures are typically cooler
(Walker and Naugle in press, p. 11).
West Nile Virus has caused population declines in wild bird
populations on the local and regional scale (Walker and Naugle in
press, p. 7) and has been shown to affect survival rates of greater
sage-grouse (Naugle et al. 2004, p. 710; Naugle et al. 2005, p. 616).
Experimental results, combined with field data, suggest that a
widespread West Nile virus infection has negatively affected greater
sage-grouse (Naugle et al. 2004, p. 711; Naugle et al. 2005, p. 616).
Summer habitat requirements of sage-grouse potentially increase their
exposure to West Nile virus. Greater sage-grouse are considered to have
a high susceptibility to West Nile virus, with resultant high levels of
mortality (Clark et al. 2006, p. 19; McLean 2006, p. 54). Data
collected on greater sage-grouse suggest that sage-grouse do not
develop a resistance to the disease, and death is certain once an
individual is exposed (Clark et al. 2006, p. 18).
To date, West Nile virus has not been documented in Gunnison sage-
grouse despite the presence of West Nile virus-positive mosquitoes in
nearly all counties throughout their range (Colorado Department of
Public Health 2004, pp. 1-5; U.S. Centers for Disease Control and
Prevention 2004, entire). We do not know whether this is a result of
the small number of birds that are marked, the relatively few birds
that exist in the wild, or unsuitable conditions in Gunnison sage-
grouse habitat for the virus to become virulent. West Nile virus
activity within the range of Gunnison sage-grouse has been low compared
to other parts of Colorado and the western United States. A total of 77
wild bird (other than Gunnison sage-grouse) deaths resulting from West
Nile virus have been confirmed from counties within the occupied range
of Gunnison sage-grouse since 2002 when reporting began in Colorado
(USGS 2009, entire). Fifty-two (68 percent) of these West-Nile-virus-
caused bird deaths were reported from Mesa County (where the Pinon Mesa
population is found). Only San Miguel, Dolores, and Hinsdale Counties
had no confirmed avian mortalities resulting from West Nile virus.
Walker and Naugle (in press, p. 27) predict that West Nile virus
outbreaks in small, isolated, and genetically depauperate populations
could reduce sage-grouse numbers below a threshold from which recovery
is unlikely because of limited or nonexistent demographic and genetic
exchange from adjacent populations. Thus, a West Nile virus outbreak in
any Gunnison sage-grouse population, except perhaps the Gunnison Basin
population, could limit the persistence of these populations.
Although West Nile virus is a potential threat, the best available
information suggests that it is not currently a significant threat to
Gunnison sage-grouse, since West Nile virus has not been documented in
Gunnison sage-grouse despite the presence of West Nile virus-positive
mosquitoes in nearly all counties throughout their range. No other
diseases or parasitic infections are considered to be threatening the
Gunnison sage-grouse at this time.
Predation
Predation is the most commonly identified cause of direct mortality
for sage-grouse during all life stages (Schroeder et al. 1999, p. 9;
Connelly et al. 2000b, p. 228; Connelly et al. in press a, p. 23).
However, sage-grouse
[[Page 59834]]
have co-evolved with a variety of predators, and their cryptic plumage
and behavioral adaptations have allowed them to persist despite this
mortality factor (Schroeder et al. 1999, p. 10; Coates 2008 p. 69;
Coates and Delehanty 2008, p. 635; Hagen in press, p. 3). Until
recently, little published information has been available that
indicates predation is a limiting factor for the greater sage-grouse
(Connelly et al. 2004, p. 10-1), particularly where habitat quality has
not been compromised (Hagen in press, p. 3). Although many predators
will consume sage-grouse, none specialize on the species (Hagen in
press, p. 5). Generalist predators have the greatest effect on ground-
nesting birds because predator numbers are independent of the density
of a single prey source since they can switch to other prey sources
when a given prey source (e.g., Gunnison sage-grouse) is not abundant
(Coates 2007, p. 4). We believe that the effects of predation observed
in greater sage-grouse are applicable to the effects anticipated in
Gunnison sage-grouse since overall behavior and life-history traits are
similar for the two species.
Major predators of adult sage-grouse include many species including
golden eagles (Aquila chrysaetos), red foxes (Vulpes fulva), and
bobcats (Felis rufus) (Hartzler 1974, pp. 532-536; Schroeder et al.
1999, pp. 10-11; Schroeder and Baydack 2001, p. 25; Rowland and Wisdom
2002, p. 14; Hagen in press, pp. 4-5). Juvenile sage-grouse also are
killed by many raptors as well as common ravens (Corvus corax), badgers
(Taxidea taxus), red foxes, coyotes (Canis latrans) and weasels
(Mustela spp.) (Braun 1995, entire; Schroeder et al. 1999, p. 10). Nest
predators include badgers, weasels, coyotes, common ravens, American
crows (Corvus brachyrhyncos) and magpies (Pica spp.), elk (Cervus
canadensis) (Holloran and Anderson 2003, p.309), and domestic cows
(Bovus spp.) (Coates et al. 2008, pp. 425-426). Ground squirrels
(Spermophilus spp.) also have been identified as nest predators
(Patterson 1952, p. 107; Schroeder et al. 1999, p. 10; Schroder and
Baydack 2001, p. 25), but recent data show that they are physically
incapable of puncturing eggs (Holloran and Anderson 2003, p. 309;
Coates et al. 2008, p. 426; Hagen in press, p. 6). Several other small
mammals visited sage-grouse nests in Nevada, but none resulted in
predation events (Coates et al. 2008, p. 425). The most common
predators of Gunnison sage-grouse eggs are weasels, ground squirrels,
coyotes, and corvids (Young 1994, p. 37). Most raptor predation of
sage-grouse is on juveniles and older age classes (GSRSC 2005, p. 135).
Golden eagles were found to be the dominant species recorded perching
on power poles in Utah in Gunnison sage-grouse habitat (Prather and
Messmer 2009, p. 12). Twenty-two and 40 percent of 111 adult
mortalities were the result of avian and mammalian predation,
respectively (Childers 2009, p. 7). Twenty-five and 35 percent of 40
chick mortalities were caused by avian and mammalian predation,
respectively (Childers 2009, p. 7). A causative agent of mortality was
not determined in the remaining depredations observed in the western
portion of the Gunnison Basin from 2000 to 2009 (Childers 2009, p. 7).
Adult male Gunnison sage-grouse are very susceptible to predation
while on the lek (Schroeder et al. 1999, p. 10; Schroeder and Baydack
2001, p. 25; Hagen in press, p. 5), presumably because they are
conspicuous while performing their mating displays. Because leks are
attended daily by numerous grouse, predators also may be attracted to
these areas during the breeding season (Braun 1995, p. 2). Connelly et
al. (2000b, p. 228) found that among 40 radio-collared males, 83
percent of the mortality was due to predation and 42 percent of those
mortalities occurred during the lekking season (March through June).
Adult female greater sage-grouse are susceptible to predators while on
the nest, but mortality rates are low (Hagen in press, p. 6). Hens will
abandon their nest when disturbed by predators (Patterson 1952, p.
110), likely reducing this mortality (Hagen in press, p. 6). Among 77
adult hens, 52 percent of the mortality was due to predation and 52
percent of those mortalities occurred between March and August, which
includes the nesting and brood-rearing periods (Connelly et al. 2000b,
p. 228). Sage-grouse populations are likely more sensitive to predation
upon females given the highly negative response of Gunnison sage-grouse
population dynamics to adult female reproductive success and chick
mortality (GSRSC, 2005, p. 173). Predation of adult sage-grouse is low
outside the lekking, nesting, and brood-rearing season (Connelly et al.
2000b, p. 230; Naugle et al. 2004, p. 711; Moynahan et al. 2006, p.
1536; Hagen in press, p. 6).
Estimates of predation rates on juveniles are limited due to the
difficulties in studying this age class (Aldridge and Boyce 2007, p.
509; Hagen in press, p. 8). For greater sage-grouse, chick mortality
from predation ranged from 10 to 51 percent in 2002 and 2003 on three
study sites in Oregon (Gregg et al. 2003a, p. 15; 2003b, p. 17).
Mortality due to predation during the first few weeks after hatching
was estimated to be 82 percent (Gregg et al. 2007, p. 648). Survival of
juveniles to their first breeding season was estimated to be low (10
percent). It is reasonable, given the sources of adult mortality, to
assume that predation is a contributor to the high juvenile mortality
rates (Crawford et al. 2004, p. 4).
Sage-grouse nests are subject to varying levels of predation.
Predation can be total (all eggs destroyed) or partial (one or more
eggs destroyed). However, hens abandon nests in either case (Coates,
2007, p. 26). Gregg et al. (1994, p. 164) reported that over a 3-year
period in Oregon, 106 of 124 nests (84 percent) were preyed upon (Gregg
et al. 1994, p. 164). Patterson (1952, p.104) reported nest predation
rates of 41 percent in Wyoming. Holloran and Anderson (2003, p. 309)
reported a predation rate of 12 percent (3 of 26) in Wyoming. Moynahan
et al. (2007, p. 1777) attributed 131 of 258 (54 percent) nest failures
to predation in Montana. Studies have shown that re-nesting rates are
low in Gunnison sage-grouse (Young, 1994, p. 44; Childers, 2009, p. 7),
suggesting that re-nesting is unlikely to offset losses due to
predation. Losses of breeding hens and young chicks to predation
potentially can influence overall greater and Gunnison sage-grouse
population numbers, as these two groups contribute most significantly
to population productivity (GSRSC, 2005, p. 29, Baxter et al. 2008, p.
185; Connelly et al, in press a, p. 18).
Nesting success of greater sage-grouse is positively correlated
with the presence of big sagebrush and grass and forb cover (Connelly
et al. 2000, p. 971). Females actively select nest sites with these
qualities (Schroeder and Baydack 2001, p. 25; Hagen et al. 2007, p.
46). Nest predation appears to be related to the amount of herbaceous
cover surrounding the nest (Gregg et al. 1994, p. 164; Braun 1995, pp.
1-2; DeLong et al. 1995, p. 90; Braun 1998; Coggins 1998, p. 30;
Connelly et al. 2000b, p. 975; Schroeder and Baydack 2001, p. 25;
Coates and Delehanty 2008, p. 636). Loss of nesting cover from any
source (e.g., grazing, fire) can reduce nest success and adult hen
survival. However, Coates (2007, p. 149) found that badger predation
was facilitated by nest cover as it attracts small mammals, a badger's
primary prey. Similarly, habitat alteration that reduces cover for
young chicks can increase their rate of predation (Schroeder and
Baydack 2001, p. 27).
In a review of published nesting studies, Connelly et al. (in
press, p. 14) reported that nesting success was greater in unaltered
habitats versus
[[Page 59835]]
habitats affected by anthropogenic activities. Where greater sage-
grouse habitat has been altered, the influx of predators can decrease
annual recruitment into a population (Gregg et al. 1994, p. 164; Braun
1995, pp. 1-2; Braun 1998; DeLong et al. 1995, p. 91; Schroeder and
Baydack 2001, p. 28; Coates 2007, p. 2; Hagen in press, p. 7).
Agricultural development, landscape fragmentation, and human
populations have the potential to increase predation pressure on all
life stages of greater sage-grouse by forcing birds to nest in less
suitable or marginal habitats, increasing travel time through altered
habitats where they are vulnerable to predation, and increasing the
diversity and density of predators (Ritchie et al. 1994, p. 125;
Schroeder and Baydack 2001, p. 25; Connelly et al. 2004, p. 7-23; and
Summers et al. 2004, p. 523). We believe the aforementioned is also
applicable to Gunnison sage-grouse because overall behavior and life-
history traits are similar for the two species (Young 1994, p. 4).
Abundance of red fox and corvids, which historically were rare in
the sagebrush landscape, has increased in association with human-
altered landscapes (Sovada et al. 1995, p. 5). In the Strawberry Valley
of Utah, low survival of greater sage-grouse may have been due to an
unusually high density of red foxes, which apparently were attracted to
that area by anthropogenic activities (Bambrough et al. 2000). The red
fox population has increased within the Gunnison Basin (BLM, 2009, p.
37). Ranches, farms, and housing developments have resulted in the
introduction of nonnative predators including domestic dogs (Canis
domesticus) and cats (Felis domesticus) into greater sage-grouse
habitats (Connelly et al. 2004, p. 12-2). We believe this is also
applicable to Gunnison sage-grouse because of the habitat similarities
of the two species and similar patterns of human development. Local
attraction of ravens to nesting hens may be facilitated by loss and
fragmentation of native shrublands, which increases exposure of nests
to potential predators (Aldridge and Boyce 2007, p. 522; Bui 2009, p.
32). The presence of ravens was negatively associated with greater
sage-grouse nest and brood fate in western Wyoming (Bui 2009, p. 27).
Raven abundance has increased as much as 1,500 percent in some
areas of western North America since the 1960s (Coates 2007, p. 5).
Breeding bird survey trends from 1966 to 2007 indicate increases
throughout Colorado and Utah (USGS, 2009, pp. 1-2). Increases in raven
numbers are suggested in the Pinon Mesa population, though data have
not been collected (CDOW 2009a, p. 110). Human-made structures in the
environment increase the effect of raven predation, particularly in low
canopy cover areas, by providing ravens with perches (Braun 1998,
pp.145-146; Coates 2007, p. 155; Bui 2009, p. 2). Reduction in patch
size and diversity of sagebrush habitat, as well as the construction of
fences, powerlines and other infrastructure also are likely to
encourage the presence of the common raven (Coates et al. 2008, p. 426;
Bui 2009, p. 4). For example, raven counts have increased by
approximately 200 percent along the Falcon-Gondor transmission line
corridor in Nevada (Atamian et al. 2007, p. 2). Atamian et al. (2007,
p. 2) found that ravens contributed to lek disturbance events in the
areas surrounding the transmission line. However, cause of decline in
surrounding sage-grouse population numbers could not be separated from
other potential impacts. Holloran (2005, p. 58) attributed increased
sage-grouse nest depredation to high corvid abundances, which resulted
from anthropogenic food and perching subsidies in areas of natural gas
development in western Wyoming. Bui (2009, p. 31) also found that
ravens used road networks associated with oil fields in the same
Wyoming location for foraging activities. Holmes (2009, pp. 2-4) also
found that common raven abundance increased in association with oil and
gas development in southwestern Wyoming. Raven abundance was strongly
associated with sage-grouse nest failure in northeastern Nevada, with
resultant negative effects on sage-grouse reproduction (Coates 2007, p.
130). The presence of high numbers of predators within a sage-grouse
nesting area may negatively affect sage-grouse productivity without
causing direct mortality. Coates (2007, pp. 85-86) suggested that
ravens may reduce the time spent off the nest by female sage-grouse,
thereby potentially compromising their ability to secure sufficient
nutrition to complete the incubation period.
As more suitable grouse habitat is converted to exurban
development, agriculture, or other non-sagebrush habitat types, grouse
nesting and brood-rearing become increasingly spatially restricted (Bui
2009, p. 32). As discussed in Factor A, we anticipate a substantial
increase in the distribution of residential development throughout the
range of Gunnison sage-grouse. This increase will likely cause
additional restriction of nesting habitat within the species' range,
given removal of sagebrush habitats and the strong selection for
sagebrush by the species. Additionally, Gunnison sage-grouse avoid
residential development, resulting in functional habitat loss (Aldridge
et al. 2010, p. 24). Ninety-one percent of nest locations in the
western portion of the Gunnison Basin population occur within 35
percent of the available habitat (Aldridge et al. 2010, p. 25-26).
Unnaturally high nest densities which result from habitat fragmentation
or disturbance associated with the presence of edges, fencerows, or
trails may increase predation rates by making foraging easier for
predators (Holloran 2005, p. C37). Increased nest density could
negatively influence the probability of a successful hatch (Holloran
and Anderson, 2005, p. 748). The influence of the human footprint in
sagebrush ecosystems may be underestimated (Leu and Hanser, in press,
pp. 24-25) since it is uncertain how much more habitat sage-grouse (a
large landscape-scale species) need for persistence in increasingly
fragmented landscapes (Connelly et al., in press, pp. 28-34).
Therefore, the influence of ravens and other predators associated with
human activities may be underestimated.
Ongoing studies in the San Miguel population suggest that the lack
of recruitment in Gunnison sage-grouse is likely due to predation (CDOW
2009a, p. 31). In this area, 6 of 12 observed nests were destroyed by
predation, with none of the chicks from the remaining nests surviving
beyond two weeks (CDOW 2009a, p. 30). In small and declining
populations, small changes to habitat abundance or quality, or in
predator abundance, could have large consequences.
Predator removal efforts have sometimes shown short-term gains that
may benefit fall populations, but not breeding population sizes (Cote
and Sutherland 1997, p. 402; Hagen in press, p. 9; Leu and Hanser in
press, p. 27). Predator removal may have greater benefits in areas with
low habitat quality, but predator numbers quickly rebound without
continual control (Hagen in press, p. 9). Red fox removal in Utah
appeared to increase adult greater sage-grouse survival and
productivity, but the study did not compare these rates against other
non-removal areas, so inferences are limited (Hagen in press, p. 11).
Slater (2003, p. 133) demonstrated that coyote control failed to
have an effect on greater sage-grouse nesting success in southwestern
Wyoming. However, coyotes may not be an important predator of sage-
grouse. In a coyote prey base analysis, Johnson and
[[Page 59836]]
Hansen (1979, p. 954) showed that sage-grouse and bird egg shells made
up a very small percentage (0.4-2.4 percent) of analyzed scat samples.
Additionally, coyote removal can have unintended consequences resulting
in the release of smaller predators, many of which, like the red fox,
may have greater negative impacts on sage-grouse (Mezquida et al. 2006,
p. 752).
Removal of ravens from an area in northeastern Nevada caused only
short-term reductions in raven populations (less than one year), as
apparently transient birds from neighboring sites repopulated the
removal area (Coates 2007, p. 151). Additionally, badger predation
appeared to partially compensate for decreases due to raven removal
(Coates 2007, p. 152). In their review of literature regarding
predation, Connelly et al. (2004, p. 10-1) noted that only two of nine
studies examining survival and nest success indicated that predation
had limited a sage-grouse population by decreasing nest success, and
both studies indicated low nest success due to predation was ultimately
related to poor nesting habitat. Bui (2009, pp. 36-37) suggested
removal of anthropogenic subsidies (e.g., landfills, tall structures)
may be an important step to reducing the presence of sage-grouse
predators. Leu and Hanser (in press, p. 27) also argue that reducing
the effects of predation on sage-grouse can only be effectively
addressed by precluding these features.
Summary of Predation
Predation has a strong relationship with anthropogenic factors on
the landscape, and human presence on the landscape will continue to
increase for the foreseeable future.
Gunnison sage-grouse are adapted to minimize predation by cryptic
plumage and behavior. Gunnison sage-grouse may be increasingly subject
to levels of predation that would not normally occur in the
historically contiguous unaltered sagebrush habitats. The impacts of
predation on greater sage-grouse can increase where habitat quality has
been compromised by anthropogenic activities (exurban development, road
development, etc.) (e.g., Coates 2007, p. 154, 155; Bui 2009, p. 16;
Hagen in press, p. 12). Landscape fragmentation, habitat degradation,
and human populations have the potential to increase predator
populations through increasing ease of securing prey and subsidizing
food sources and nest or den substrate. Thus, otherwise suitable
habitat may change into a habitat sink for grouse populations (Aldridge
and Boyce 2007, p. 517).
Anthropogenic influences on sagebrush habitats that increase
suitability for ravens may also limit sage-grouse populations (Bui
2009, p. 32). Current land-use practices in the intermountain West
favor high predator (in particular, raven) abundance relative to
historical numbers (Coates et al. 2008, p. 426). The interaction
between changes in habitat and predation may have substantial effects
to the Gunnison sage-grouse at the landscape level (Coates 2007, p. 3-
5). Since the Gunnison and greater sage-grouse have such similar
behavior and life-history traits, we believe the current impacts on
Gunnison sage-grouse are at least as significant as those documented in
greater sage-grouse and to date in Gunnison sage-grouse. Given the
small population sizes and fragmented nature of the remaining Gunnison
sage-grouse habitat, we believe that the impacts of predation will
likely be even greater as habitat fragmentation continues.
The studies presented above for greater sage-grouse suggest that,
in areas of intensive habitat alteration and fragmentation, sage-grouse
productivity and, therefore, populations could be negatively affected
by increasing predation. Nest predation may be higher, more variable,
and have a greater impact on the small, fragmented Gunnison sage-grouse
populations, particularly the six smallest populations (GSRSC 2005, p.
134). Unfortunately, except for the relatively few studies presented
here, data are lacking that link Gunnison sage-grouse population
numbers and predator abundance. However, in at least six of the seven
populations (Gunnison Basin potentially excluded), where habitats have
been significantly altered by human activities, we believe that
predation could be limiting Gunnison sage-grouse populations. As more
habitats face development, even dispersed development such as that
occurring throughout the range of Gunnison sage-grouse, we expect this
threat to spread and increase. Studies of the effectiveness of predator
control have failed to demonstrate a long-term inverse relationship
between the predator numbers and sage-grouse nesting success or
population numbers. Therefore, we believe that predation is currently a
threat to the Gunnison sage-grouse and will continue to be a threat to
the species within the foreseeable future.
Summary of Factor C
We have reviewed the available information on the effects of
disease and predation on the Gunnison sage-grouse. The only disease
that currently presents a potential impact to the Gunnison sage-grouse
is West Nile virus. This virus is distributed throughout most of the
species' range. However, despite its near 100 percent lethality,
disease occurrence is sporadic in other taxa across the species' range
and has not been detected to date in Gunnison sage-grouse. While we
have no evidence of West Nile virus acting on the Gunnison sage-grouse,
because of its presence within the species' range and the continued
development of anthropogenic water sources in the area, the virus may
pose a future threat to the species. We anticipate that West Nile virus
will persist within the range of Gunnison sage-grouse indefinitely and
will be exacerbated by any factor (e.g., climate change) that increases
ambient temperatures and the presence of the vector on the landscape.
We believe that existing and continued landscape fragmentation will
increase the effects of predation on this species, particularly in the
six smaller populations, resulting in a reduction in sage-grouse
productivity and abundance in the future.
We have evaluated the best available scientific information
regarding disease and predation and their effects on the Gunnison sage-
grouse. Based on the information available, we have determined that
predation is a significant threat to the species throughout all or a
significant portion of its range. Furthermore, we determine that
disease is not currently a significant threat but has the potential to
become a significant threat at any time.
D. The Inadequacy of Existing Regulatory Mechanisms
Under this factor, we examine whether threats to the Gunnison sage-
grouse are adequately addressed by existing regulatory mechanisms.
Existing regulatory mechanisms that could provide some protection for
Gunnison sage-grouse include: (1) local land use laws, processes, and
ordinances; (2) State laws and regulations; and (3) Federal laws and
regulations. An example of a regulatory mechanism is the terms and
conditions attached to a grazing permit that describe how a permittee
will manage livestock on a BLM allotment. They are non-discretionary
and enforceable, and are considered a regulatory mechanism under this
analysis. Other examples include city or county ordinances, State
governmental actions enforced under a State statute or constitution, or
Federal action under statute. Actions adopted by local groups, States,
or Federal entities that are discretionary or are not enforceable,
including conservation
[[Page 59837]]
strategies and guidance, are typically not regulatory mechanisms.
Regulatory mechanisms, if they exist, may preclude the need for
listing if such mechanisms are judged to adequately address the threat
to the species such that listing is not warranted. Conversely, threats
on the landscape are exacerbated when not addressed by existing
regulatory mechanisms, or when the existing mechanisms are not adequate
(or not adequately implemented or enforced). We cannot predict when or
how local, State, and Federal laws, regulations, and policies will
change; however, most Federal land use plans are valid for at least 20
years. In this section we review actions undertaken by local, State,
and Federal entities designed to reduce or remove threats to Gunnison
sage-grouse and its habitat.
Local Laws and Regulations
Rangewide approximately 41 percent of occupied Gunnison sage-grouse
habitat is privately owned (calculation from Table 1). Gunnison County
and San Miguel County, Colorado, are the only local or County entities
that have regulations and policy, respectively, that provide a level of
conservation consideration for the Gunnison sage-grouse or its habitats
on private land (Dolores County 2002; Mesa County 2003; Montrose County
2003). In 2007, the Gunnison County, Colorado Board of County
Commissioners approved Land Use Resolution (LUR) Number 07-17 to ensure
all applications for land use change permits, including building
permits, individual sewage disposal system permits, Gunnison County
access permits, and Gunnison County Reclamation permits be reviewed for
impact to Gunnison sage-grouse habitat within 1 km (0.6 mile) of an
active lek. If impacts are determined to result from a project, impacts
are to be avoided, minimized, and/or mitigated. Approximately 79
percent of private land occupied by the Gunnison Basin population is in
Gunnison County, and thereby under the purview of these regulations.
The remaining 21 percent of the private lands in the Gunnison Basin
population is in Saguache County where similar regulations are not in
place or applicable. Actions outside the 1 km (0.6 mi) buffer are not
subject to Gunnison County LUR 07-17.
Colorado State statute (C.R.S. 30-28-101) exempts parcels of land
of 14 ha (35 ac) or more per home from regulation, so county zoning
laws in Colorado such as LUR 07-17 only apply to properties with
housing densities greater than one house per 14 ha (35 ac). This
statute allows these parcels to be exempt from county regulation and
may negatively affect Gunnison sage-grouse by allowing for further
development, degradation, and loss of the species' habitat. A total of
1,190 parcels, covering 16,351 ha (40,405 ac), within occupied habitat
in Gunnison County currently contain development. Of those 1,190
parcels, 851 are less than 14 ha (35 ac) in size and subject to County
review. However, those 851 parcels encompass only 13.1 percent of
private land area with existing development in occupied habitat within
Gunnison County. Parcels greater than 14 ha (35 ac) in size (339 of the
1,190) encompass 86.9 of the existing private land area within occupied
habitat within Gunnison County. Cumulatively, 91 percent of the private
land within the Gunnison County portion of the Gunnison Basin
population that either has existing development or is potentially
developable land is allocated in lots greater than 14 ha (35 ac) in
size and therefore not subject to Gunnison County LUR 07-17. This
situation limits the effectiveness of LUR 07-17 in providing protection
to Gunnison sage-grouse in Gunnison County.
The only required review by Gunnison County under LUR 07-17
pertains to the construction of roads, driveways, and individual
building permits. Of the 79 percent of area occupied by the Gunnison
Basin population that falls within Gunnison County, 37 percent of the
private land is not subject to the County LUR because the action would
not be within 1 km (0.6 mi) of a lek. Gunnison County reviewed 231
projects from July 2006 through November 2009 under the LUR for impacts
to Gunnison sage-grouse. All but one project was within the overall
boundary of the Gunnison Basin population's occupied habitat, with most
of the activity focused in the northern portion of this population. All
of these projects were approved and allowed to proceed. The majority of
these projects were within established areas of development, and some
were for activities such as outbuildings or additions to existing
buildings; nonetheless, these projects provide an indication of further
encroachment and fragmentation of the remaining occupied habitat.
Nineteen percent (44) of the projects were within 1 km (0.6 mi) of a
lek. Nineteen percent (45) of the projects contained language within
the permit that established conditions for control of pets. The use of
the 1-km (0.6-mi) buffer around the lek provides some conservation
benefit to the grouse. This buffer is not as large as that recommended
by GSRSC (2005 entire) to meet all the species' year-round life-history
needs (6.4 km (4 mi)). Because research summarized in GSRSC (2005
entire) has shown that impacts occur up to 6.4 km (4 mi) from the point
of disturbance, these minimally or unregulated negative impacts will
continue to fragment the habitat and thus have substantial impacts on
the local, as well as landscape, conservation of the species. In
summary, Gunnison County is to be highly commended for the regulatory
steps they have implemented. However, the scope and implementation of
that regulatory authority is limited in its ability to effectively and
collectively conserve Gunnison sage-grouse due to the County's limited
authority within the Gunnison Basin portion of the species' range.
In 2005, San Miguel County amended its Land Use Codes to include
consideration and implementation, to the extent possible, of
conservation measures recommended in GSRSC (2005, entire) for the
Gunnison sage-grouse when considering land use activities and
development located within its habitat (San Miguel County 2005). The
County is only involved when there is a request for a special use
permit, which limits their involvement in review of projects adversely
affecting Gunnison sage-grouse and their habitat and providing
recommendations. Conservation measures are solicited from the CDOW and
a local Gunnison sage-grouse working group. Implementation of the
conservation measure is dependent on negotiations between the County
and the applicant. Some positive measures (e.g., locating a special use
activity outside grouse habitat, establishing a 324-ha (800-ac)
conservation easement; implementing speed limits to reduce likelihood
of bird/vehicle collisions) have been implemented as a result of the
policy. Typically, the County has not been involved with residential
development, and most measures that result from discussions with
applicants result in measures that the Service considers minimization,
not mitigation measures, but which the County considers mitigation
(Henderson 2010, pers. comm.). The San Miguel County Land Use Codes
provide some conservation benefit to the species through some
minimization of impacts and encouraging landowners to voluntarily
minimize/mitigate impacts of residential development in grouse habitat.
However, the codes allow for limited regulatory authority but are not
sufficient to prevent or mitigate for the continued degradation and
[[Page 59838]]
fragmentation of Gunnison sage-grouse habitat.
In addition to the county regulations, Gunnison County hired a
Gunnison Sage-grouse Coordinator (2005 to present) and organized a
Strategic Committee (2005 to present) to facilitate implementation of
conservation measures in the Gunnison Basin under both the local
Conservation Plan and Rangewide Conservation Plan (RCP) (GSRSC 2005).
San Miguel County hired a Gunnison Sage-grouse Coordinator for the San
Miguel Basin population in March 2006. The Crawford working group hired
a Gunnison sage-grouse coordinator in December 2009. Saguache County
has applied for a grant to hire a part-time coordinator for the Poncha
Pass population (grant status still pending). These efforts facilitate
coordination relative to sage-grouse management and reflect positively
on these Counties' willingness to conserve Gunnison sage-grouse, but
have no regulatory authority. None of the other Counties with Gunnison
sage-grouse populations have regulations, or staff, that implement
regulation or policy review that consider the conservation needs of
Gunnison sage-grouse. The inadequacy of existing regulatory mechanisms
that address habitat loss, fragmentation, and degradation, in the other
populations constitutes a threat to those populations.
Conservation measures that have regulatory authority that have been
implemented as a result of the aforementioned collective efforts
include: closing of shed antler collection in the Gunnison Basin by the
Colorado Wildlife Commission due to its disturbance of Gunnison sage-
grouse during the early breeding season; and a BLM/USFS/Gunnison
County/CDOW collective effort to implement and enforce road closures
during the early breeding season (March 15 to May 15). These regulatory
efforts have provided benefits to Gunnison sage-grouse during the
breeding season. However, these measures do not adequately address the
primary threat to the species of fragmentation of the habitat.
Habitat loss is not regulated or monitored in Colorado counties
where Gunnison sage-grouse occur. Therefore, conversion of agricultural
land from one use to another, such as native pasture containing
sagebrush converted to another use, such as cropland, would not
normally come before a county zoning commission. Based on the
information we have available for the range of the species, we do not
believe that habitat loss from conversion of sagebrush habitat to
agricultural lands is occurring at a level that makes it a threat. The
permanent loss, and associated fragmentation and degradation, of
sagebrush habitat is considered the largest threat to Gunnison sage-
grouse (GSRSC 2005, p. 2). The minimally regulated residential/exurban
development found throughout the vast majority of the species range is
a primary cause of this loss, fragmentation, and degradation of
Gunnison sage-grouse habitat. We are not aware of any existing local
regulatory mechanisms that adequately address this threat.
We recognize that county or city ordinances in San Juan County,
Utah, that address agricultural lands, transportation, and zoning for
various types of land uses have the potential to influence sage-grouse.
However, we are not aware of any existing County regulations that
provide adequate regulatory mechanisms to address threats to the
Gunnison sage-grouse and its habitat.
Each of the seven populations of Gunnison sage-grouse has a
Conservation Plan written by the respective local working group with
publication dates of 1999 to 2009. These plans provide recommendations
for management of Gunnison sage-grouse and have been the basis for
identifying and prioritizing local conservation efforts, but do not
provide regulatory protection for Gunnison sage-grouse or its habitat.
State Laws and Regulations
State laws and regulations provide specific authority for sage-
grouse conservation over lands that are directly owned by the State,
provide broad authority to regulate and protect wildlife on all lands
within their borders, and provide a mechanism for indirect conservation
through regulation of threats to the species (e.g., noxious weeds).
Colorado Revised Statutes, Title 33, Article 1 gives CDOW
responsibility for the management and conservation of wildlife
resources within State borders. Title 33 Article 1-101, Legislative
Declaration requires a continuous operation of planning, acquisition,
and development of wildlife habitats and facilities for wildlife-
related opportunities. The CDOW is required by statute (C.R.S. 106-7-
104) to provide counties with information on ``significant wildlife
habitat,'' and provide technical assistance in establishing guidelines
for designating and administering such areas, if asked. The CDOW also
has authority to regulate possession of the Gunnison sage-grouse, set
hunting seasons, and issue citations for poaching. These authorities
provide individual Gunnison sage-grouse with protection from direct
human-caused mortality to the level that hunting is not considered a
threat to the species (see Factor B discussion, above). The Colorado
Wildlife Commission is currently considering whether to include the
Gunnison sage-grouse as an endangered or threatened species in
accordance with Administrative Directive W-7 (State of Colorado, 2007,
entire). These authorities do not regulate the primary threat to the
species of fragmentation of habitat as described in Factor A.
The Wildlife Resources Code of Utah (Title 23) provides UDWR the
powers, duties, rights, and responsibilities to protect, propagate,
manage, conserve, and distribute wildlife throughout the State. Section
23-13-3 declares that wildlife existing within the State, not held by
private ownership and legally acquired, is property of the State.
Sections 23-14-18 and 23-14-19 authorize the Utah Wildlife Board to
prescribe rules and regulations for the taking and/or possession of
protected wildlife, including Gunnison sage-grouse. These authorities
provide adequate protection to individual Gunnison sage-grouse from
direct, human-caused mortality to the level that hunting is not
considered a threat to the species (see Factor B discussion, above).
However, these laws and regulations do not provide the regulatory
authority needed to conserve sage-grouse habitats from the threats
described in Factor A.
Gunnison sage-grouse are managed by CDOW and UDWR on all lands
within each State as resident native game birds. In both States this
classification allows the direct human taking of the bird during
hunting seasons authorized and conducted under State laws and
regulations. In 2000, CDOW closed the hunting season for Gunnison sage-
grouse in the Gunnison Basin, the only area then open to hunting for
the species. The hunting season for Gunnison sage-grouse in Utah has
been closed since 1989. The Gunnison sage-grouse is listed as a species
of special concern in Colorado, as a sensitive species in Utah, and as
a Tier I species under the Utah Wildlife Action Plan, providing
heightened priority for management (CDOW 2009a, p. 40; UDWR 2009, p.
9). The Colorado Wildlife Commission is currently considering a
proposal from CDOW to list the Gunnison sage-grouse as a State
endangered or threatened species. State listed species will be the
focus of conservation actions such as monitoring, research,
enhancement, restoration, or inventory, and will receive preferential
consideration in the
[[Page 59839]]
annual budget development process (State of Colorado, 2007, p. 1).
Hunting and other State regulations that deal with issues such as
harassment provide adequate protection for individual birds (see
discussion under Factor B), but do not protect the habitat. While we
strongly support the use of regulatory mechanisms to control hunting of
the species, the protection afforded through the aforementioned State
regulatory mechanisms is limited.
Easements that prevent long-term or permanent habitat loss by
prohibiting development are held by CDOW, UDWR, Natural Resources
Conservation Service (NRCS), NPS, and non-governmental organizations
(Table 4). Although the decision of whether to enter into a
conservation easement is voluntary on the part of the landowner,
conservation easements are legally binding documents. Therefore, we
have determined that perpetual conservation easements offer some level
of regulatory protection to the species. Some of the easements include
conservation measures that are specific for Gunnison sage-grouse, while
many are directed at other species, such as big game (GSRSC 2005, pp.
59-103). Some of these easements protect existing Gunnison sage-grouse
habitat. Sixty-nine percent of the area under conservation easements
have land cover types other than agricultural (covering 31 percent)
that provide habitat for Gunnison sage-grouse. However, considering
that the total easements recorded to date cover only 5.1 percent of
private lands rangewide, that not all easements have sage-grouse
specific habitat or conservation measures, and their scattered
distribution throughout the range of the species, we believe that while
easements provide some level of protection from future development,
they are not sufficient to ameliorate the threat of loss and
fragmentation of Gunnison sage-grouse habitat. We believe this to be
true now and into the future, especially considering the costs of
purchasing easements when compared to the cost paid for development of
those lands, and money available through all sources to purchase
easements. In addition, because entering into a conservation easement
is voluntary on the part of the landowner, we cannot be sure that any
future conservation easements will occur in such a configuration and
magnitude that they will offer the species or its habitat substantial
protection.
Table 4. Area of conservation easements in hectares (ha) and acres (ac)
by population and percentage of occupied habitat in conservation
easements as of September 2009.
------------------------------------------------------------------------
Percent of
Occupied
Population hectares acres Habitat in
Respective
Population
------------------------------------------------------------------------
Gunnison Basin 11,334 28,008 4.7
------------------------------------------------------------------------
Pi[ntilde]on Mesa 4,270 10,551 27.1
------------------------------------------------------------------------
Cerro Summit-Cimarron-Sims Mesa 1,395 3,447 9.3
------------------------------------------------------------------------
Monticello 1,036 2,560 3.6
------------------------------------------------------------------------
San Miguel Basin 843 2,084 2.1
------------------------------------------------------------------------
Dove Creek Group 330 815 2.0
------------------------------------------------------------------------
Crawford 249 616 1.8
------------------------------------------------------------------------
Poncha Pass 0 0 0
------------------------------------------------------------------------
Rangewide 19,457 48,081 5.1
------------------------------------------------------------------------
The CDOW has been implementing the CCAA referenced earlier in this
document. As of February 2010, 4 landowners have completed Certificates
of Inclusion (CI) for their properties enrolling 2,581 ha (6,377 ac).
Because the Service issues a permit to applicants with an approved
CCAA, we have some regulatory oversight over the implementation of the
CCAA. However, permit holders and landowners can voluntarily opt out of
the CCAA at any time. Thus, the CCAA provides important conservation
measures that assist the species, and provides regulatory protection to
enrolled landowners, but due to its voluntary nature, provides no
regulatory protection. An additional 38 landowners (totaling
approximately 18,211 ha (45,000 ac) within Gunnison sage-grouse
occupied habitat), have worked with the CDOW to complete baseline
reports in preparation for issuance of CIs. The reports describe
property infrastructure and number of acres of Gunnison sage-grouse
seasonal habitat. A CDOW review of all these reports and the condition
of the habitat is pending. The CCAA/CI efforts described in this
paragragh will provide conservation benefits to Gunnison sage-grouse
throughout their range where they are in place (27 in the Gunnison
Basin, 3 in San Miguel, 2 in Crawford, 5 in Pinon Mesa, 1 in Dove
Creek). Even assuming the area of all landowners expressing interest
and with completed baselines will ultimately be covered under CIs, the
fact remains that these properties constitute only 13 percent of the
total private land throughout the species range and that they are
scattered throughout the species range. Therefore, we do not believe
the CCAA/CI efforts would provide adequate regulatory coverage to
ensure the long-term conservation of the species on private lands.
On April 22, 2009, the Governor of Colorado signed into law new
rules (House Bill 1298) for the Colorado Oil and Gas Conservation
Commission (COGCC), which is the entity responsible for permitting oil
and gas well development in Colorado (COGCC 2009, entire). The rules
went into effect on private lands on April 1, 2009, and on Federal
lands July 1, 2009. The new rules require that permittees and
[[Page 59840]]
operators determine whether their proposed development location
overlaps with ``sensitive wildlife habitat,'' or is within a restricted
surface occupancy (RSO) area. For Gunnison sage-grouse, areas within 1
km (0.6 mi) of an active lek can be designated as RSOs (CDOW 2009a, p.
27), and surface area occupancy will be avoided except in cases of
economic or technical infeasibility (CDOW 2009a, p. 27). Areas within
approximately 6.4 km (4 mi) of an active lek are considered sensitive
wildlife habitat (CDOW 2009a, p. 27) and the development proponent is
required to consult with the CDOW to identify measures to (1) avoid
impacts on wildlife resources, including sage-grouse; (2) minimize the
extent and severity of those impacts that cannot be avoided; and (3)
mitigate those effects that cannot be avoided or minimized (COGCC 2009,
section 1202.a). The COGCC will consider CDOW's recommendations in the
permitting decision, although the final permitting and conditioning
authority remains with COGCC. As stated in Section 1202.d of the new
rules, consultation with CDOW is not required under certain
circumstances such as, the issuance of a variance by the Director of
the COGCC, the existence of a previously CDOW-approved wildlife
mitigation plan, and others. Other categories for potential exemptions
also can be found in the new rules (e.g., 1203.b).
Because the new rules have only been in place for less than a year
and their implementation is still being discussed, it remains to be
seen what level of protection will be afforded to Gunnison sage-grouse.
The new rules could provide for greater consideration of the
conservation needs of the species. It should be noted that leases that
have already been approved but not drilled (e.g., COGCC 2009,
1202.d(1)), or drilling operations that are already on the landscape,
may continue to operate without further restriction into the future. We
are not aware of any situations where RSOs have been effectively
applied or where conservation measures have been implemented for
potential oil and gas development impacts to Gunnison sage-grouse on
private lands underlain with privately owned minerals, which are
regulated by the appropriate governing bodies.
Colorado and Utah have laws that directly address the priorities
for use of State school section lands, which require that management of
these properties be based on maximizing financial returns. State school
section lands account for only one percent of occupied habitat in
Colorado and one percent in Utah, so impacts may be considered
negligible. We are not aware of any conservation measures that will be
implemented under regulatory authority for Gunnison sage-grouse on
State school section lands, other than a request to withdraw or apply
``no surface occupancy'' and conservation measures from the RCP (GSRSC
2005) to four sections available for oil and gas leasing in the San
Miguel Basin population (see Factor A for further discussion). The
State Land Board (SLB) recently purchased the Miramonte Meadows
property (approximately 809 ha (2,000 ac) next to the Dan Noble State
Wildlife Area (SWA). Roughly 526 ha (1,300 ac) is considered prime
Gunnison sage-grouse habitat (Garner 2010, pers. comm.). Discussions
with the SLB have indicated a willingness to implement habitat
improvements (juniper removal) on the property. They have also accepted
an application to designate the tract as a ``Stewardship Trust''
parcel. The Stewardship Trust program is capped at 119,383 to 121,406
ha (295,000 to 300,000 ac), and no more property can be added until
another tract is removed from the program. Because of this cap, it is
unknown if or when the designation of the tract as a Stewardship Trust
parcel may occur. The scattered nature of State school sections (single
sections) across the landscape and the requirement to conduct
activities to maximize financial returns minimize the likelihood of
implementation of measures that will benefit Gunnison sage-grouse.
Thus, mechanisms present on State trust lands are inadequate to
minimize degradation and fragmentation of habitat and thus ensure
conservation of the species.
Some States require landowners to control noxious weeds, a
potential habitat threat to sage-grouse (as discussed in Factor A). The
types of plants considered to be noxious weeds vary by State.
Cheatgrass is listed as a Class C species in Colorado (Colorado
Department of Agriculture 2010, p. 3). The Class C designation
delegates to local governments the choice of whether or not to
implement activities for the control of cheatgrass. Gunnison, Saguache,
and Hinsdale Counties target cheatgrass with herbicide applications
(GWWC 2009, pp. 2- 3). The CDOW annually sprays for weeds on SWAs (CDOW
2009a, p. 106). The State of Utah does not consider cheatgrass as
noxious within the State (Utah Department of Agriculture 2010, p. 1)
nor in San Juan County (Utah Department of Agriculture 2010a, p. 1).
The laws dealing with other noxious and invasive weeds may provide some
protection for sage-grouse in local areas by requiring some control of
the invasive plants, although large-scale control of the most
problematic invasive plants is not occurring. Rehabilitation and
restoration techniques for sagebrush habitats are mostly unproven and
experimental (Pyke in press, p. 25). Regulatory authority has not been
demonstrated to be effective in addressing the overall impacts of
invasive plants on the degradation and fragmentation of sagebrush
habitat within the species range.
Federal Laws and Regulations
Gunnison sage-grouse are not covered or managed under the
provisions of the Migratory Bird Treaty Act (16 U.S.C. 703-712) because
they are considered resident game species. Federal agencies are
responsible for managing 54 percent of the total Gunnison sage-grouse
habitat. The Federal agencies with the most sagebrush habitat are BLM,
an agency of the Department of the Interior, and USFS, an agency of the
Department of Agriculture. The NPS in the Department of the Interior
also has responsibility for lands that contain Gunnison sage-grouse
habitat.
BLM
About 42 percent of Gunnison sage-grouse occupied habitat is on
BLM-administered land (Table 1 details percent ownership within each
population). The Federal Land Policy and Management Act of 1976 (FLPMA)
(43 U.S.C. 1701 et seq.) is the primary Federal law governing most land
uses on BLM-administered lands. Section 102(a)(8) of FLPMA specifically
recognizes wildlife and fish resources as being among the uses for
which these lands are to be managed. Regulations pursuant to FLPMA and
the Mineral Leasing Act (30 U.S.C. 181 et seq.) that address wildlife
habitat protection on BLM-administered land include 43 CFR 3162.3-1 and
43 CFR 3162.5-1; 43 CFR 4120 et seq.; and 43 CFR 4180 et seq.
Gunnison sage-grouse have been designated as a BLM Sensitive
Species since they were first identified and described in 2000 (BLM
2009, p. 7). The management guidance afforded sensitive species under
BLM Manual 6840 - Special Status Species Management (BLM 2008, entire)
states that ``Bureau sensitive species will be managed consistent with
species and habitat management objectives in land use and
implementation plans to promote their conservation and to minimize the
likelihood and need for listing under the ESA'' (BLM 2008, p. 05V). BLM
Manual 6840 further requires
[[Page 59841]]
that Resource Management Plans (RMPs) should address sensitive species,
and that implementation ``should consider all site-specific methods and
procedures needed to bring species and their habitats to the condition
under which management under the Bureau sensitive species policies
would no longer be necessary'' (BLM 2008, p. 2A1). As a designated
sensitive species under BLM Manual 6840, sage-grouse conservation must
be addressed in the development and implementation of RMPs on BLM
lands.
RMPs are the basis for all actions and authorizations involving
BLM-administered lands and resources. They establish allowable resource
uses, resource condition goals and objectives to be attained, program
constraints and general management practices needed to attain the goals
and objectives, general implementation sequences, and intervals and
standards for monitoring and evaluating the plan to determine its
effectiveness and the need for amendment or revision (43 CFR 1601.0-
5(k)).
The RMPs provide a framework and programmatic guidance for activity
plans, which are site-specific plans written to implement decisions
made in a RMP. Examples include Allotment Management Plans that address
livestock grazing, oil and gas field development, travel management
(motorized and mechanized road and trail use), and wildlife habitat
management. Activity plan decisions normally require additional
planning and National Environmental Policy Act (NEPA) analysis. If an
RMP contains specific direction regarding sage-grouse habitat,
conservation, or management, it represents an enforceable regulatory
mechanism to ensure that the species and its habitats are considered
during permitting and other decision-making on BLM lands.
The BLM manages Gunnison sage-grouse habitat under five existing
RMPs. These RMPs contain some specific measures or direction pertinent
to management of Gunnison sage-grouse or their habitats. Three of these
RMPs (San Juan, Grand Junction, and Uncompahgre- covering all or
portions of the San Miguel, Pinon Mesa, Crawford, and Cerro Summit-
Cimarron-Sims Mesa populations, and the Dove Creek group) are in
various stages of revision. All RMPs currently propose some
conservation measures (measures that if implemented should provide a
level of benefit to Gunnison sage-grouse) outlined in GSRSC (2005,
entire) or local Gunnison sage-grouse Conservation Plans through
project- or activity-level NEPA reviews (BLM 2009, p. 6). In addition,
several offices have undergone other program-level planning, such as
travel management, that incorporate some conservation measures to
benefit the species (BLM 2009, p. 6). However, the information provided
to us by the BLM in Colorado did not specify what requirements,
direction, measures, or guidance will ultimately be included in the
revised Colorado RMPs to address threats to sage-grouse and sagebrush
habitat. Additionally we do not know the effectiveness of these
proposed measures.
We do not have information on RMP implementation by Utah BLM.
Therefore, we cannot assess the future value of BLM RMPs as regulatory
mechanisms for the conservation of the Gunnison sage-grouse. Current
BLM RMPs provide some limited regulatory authority as they are being
implemented through project-level planning (e.g., travel management
(the management of the motorized and nonmotorized use of public lands)
and grazing permit renewals). We do not know the final measures that
will be included in the revised RMPs and therefore what will be
implemented, so we cannot evaluate their effectiveness. Based on
modeling results demonstrating the effects of roads on Gunnison sage-
grouse (Aldridge and Saher 2010 entire - discussed in detail in Factor
A), we believe that implementation of even the most restrictive travel
management alternatives proposed by the BLM and USFS will still result
in further degradation and fragmentation of Gunnison sage-grouse
habitat in the Gunnison Basin.
In addition to land use planning, BLM uses Instruction Memoranda
(IM) to provide instruction to district and field offices regarding
specific resource issues. Instruction Memoranda are guidance that
require a process to be followed but do not mandate results.
Additionally, IMs are of short duration (1 to 2 years) and are intended
to address resource concerns by providing direction to staff until a
threat passes or the resource issue can be addressed in a long-term
planning document. BLM issued IM Number CO-2005-038 on July 12, 2005,
stating BLM's intent and commitment to assist with and participate in
the implementation of the RCP. Although this IM has not been formally
updated or reissued, it continues to be used for BLM-administered lands
in the State (BLM 2009, p. 6).
The BLM has regulatory authority for oil and gas leasing on Federal
lands and on private lands with a severed Federal mineral estate, as
provided at 43 CFR 3100 et seq., and they are authorized to require
stipulations as a condition of issuing a lease. The BLM's planning
handbook has program-specific guidance for fluid minerals (which
include oil and gas) that specifies that RMP decisions will identify
restrictions on areas subject to leasing, including closures, as well
as lease stipulations (BLM 2000, Appendix C, p.16). The handbook also
specifies that all stipulations must have waiver, exception, or
modification criteria documented in the plan, and notes that the least
restrictive constraint to meet the resource protection objective should
be used (BLM 2000, Appendix C, p. 16). The BLM has regulatory authority
to condition ``Application for Permit to Drill'' authorizations,
conducted under a lease that does not contain specific sage-grouse
conservation stipulations, but utilization of conditions is
discretionary and we are uncertain as to how this authority will be
applied. Also, oil and gas leases have a 200-m (650-ft) stipulation,
which allows movement of the drilling area by that distance to avoid
sensitive resources. Many of the BLM field offices work with the
operators to move a proposed drilling site farther or justify such a
move through the site-specific NEPA process.
For existing oil and gas leases on BLM land in occupied Gunnison
sage-grouse habitat, oil and gas companies can conduct drilling
operations if they wish, but are always subject to permit conditions.
The BLM has stopped issuing new drilling leases in occupied sage-grouse
habitat in Colorado at least until the new RMPs are in place. All
occupied habitat in the Crawford Area and Gunnison Basin populations
are covered by this policy. However, leases already exist in 17 percent
of the Pinon Mesa population, and 49 percent of the San Miguel Basin
population. Given the already small and fragmented nature of the
populations where oil and gas leases are likely to occur, additional
development within occupied habitat would negatively impact those
populations by causing additional actual and functional habitat loss
and fragmentation. Since we do not know what minimization and
mitigation measures might be applied, we cannot assess the overall
conservation impacts to those populations.
The oil and gas leasing regulations authorize BLM to modify or
waive lease terms and stipulations if the authorized officer determines
that the factors leading to inclusion of the term or stipulation have
changed sufficiently to no longer justify protection, or if proposed
operations would not cause unacceptable impacts (43 CFR 3101.1-
[[Page 59842]]
4). The Service has no information indicating that the BLM has granted
any waivers of stipulations pertaining to the Gunnison sage-grouse and
their habitat.
The Energy Policy and Conservation Act of 2000 included provisions
requiring the Secretary of the Department of the Interior to conduct a
scientific inventory of all onshore Federal lands to identify oil and
gas resources underlying these lands and the nature and extent of any
restrictions or impediments to the development of such resources
(U.S.C. Title 42, Chapter 77, Sec. 6217(a)). On May 18, 2001, President
Bush signed Executive Order 13212-Actions to Expedite Energy-Related
Projects (66 FR 28357, May 22, 2001), which states that the executive
departments and agencies shall take appropriate actions, to the extent
consistent with applicable law, to expedite projects that will increase
the production, transmission, or conservation of energy. The Executive
Order specifies that this includes expediting review of permits or
taking other actions as necessary to accelerate the completion of
projects, while maintaining safety, public health, and environmental
protections. Due to the relatively small amount of energy development
activities occurring within Gunnison sage-grouse habitat (with the
exception of the Dry Creek Basin subpopulation of the San Miguel
population), we believe that energy development activities are not a
significant threat. However, given scenarios such as Dry Creek Basin,
if the level of energy development activities should increase, current
regulations and policies do not provide adequate regulatory protection
to prevent oil and gas development from becoming a threat to this
subpopulation.
As stated previously, Gunnison sage-grouse are considered a BLM
Sensitive Species and therefore receive Special Status Species
management considerations. The BLM regulatory authority for grazing
management is provided at 43 CFR 4100 (Regulations on Grazing
Administration Exclusive of Alaska). Livestock grazing permits and
leases contain terms and conditions determined by BLM to be appropriate
to achieve management and resource condition objectives on the public
lands and other lands administered by BLM, and to ensure that habitats
are, or are making significant progress toward being, restored or
maintained for BLM special status species (43 CFR 4180.1(d)). The State
or regional standards for grazing administration must address habitat
for endangered, threatened, proposed, candidate, or special status
species, and habitat quality for native plant and animal populations
and communities (43 CFR 4180.2(d)(4) and (5)). The guidelines must
address restoring, maintaining, or enhancing habitats of BLM special
status species to promote their conservation, as well as maintaining or
promoting the physical and biological conditions to sustain native
populations and communities (43 CFR 4180.2(e)(9) and (10). The BLM is
required to take appropriate action not later than the start of the
next grazing year upon determining that existing grazing practices or
levels of grazing use are significant factors in failing to achieve the
standards and conform with the guidelines (43 CFR 4180.2(c)).
The BLM agreed to work with their resource advisory councils to
expand the rangeland health standards required under 43 CFR 4180 so
that there are public land health standards relevant to all ecosystems,
not just rangelands, and that they apply to all BLM actions, not just
livestock grazing (BLM Manual 180.06.A). Both Colorado and Utah have
resource advisory councils. Within the Gunnison Basin population, 16
percent of the BLM and USFS allotment management plans in occupied
habitat currently have incorporated Gunnison sage-grouse habitat
objectives (USFWS, 2010c, entire). Rangewide, of the offices providing
information specific to allotment management plans, only 24 percent of
148 BLM and USFS grazing allotments have thus far incorporated Gunnison
sage-grouse habitat objectives into the allotment management plans or
in permit renewals. Land health objectives were being met in 37 of the
80 (46 percent) BLM active allotments for which data were reported.
Land Health Assessments (LHAs) were not conducted in an additional 20
allotments.
The BLM Gunnison Field Office conducted Gunnison sage-grouse
habitat assessments in two major occupied habitat locations in the
Gunnison Basin population quantifying vegetation structural
characteristics and plant species diversity. Data were collected and
compared to Gunnison sage-grouse Structural Habitat Guidelines (GSRSC,
2005, Appendix H) during optimal growing conditions in these two major
occupied areas. Guidelines for sage cover, grass cover, forb cover,
sagebrush height, grass height, and forb height were met in 45, 30, 25,
75, 81, and 39 percent, respectively, of 97 transects (BLM 2009, pp.
31-32). Using the results of the two assessments along with results
from LHAs, habitat conditions are not being adequately managed to meet
the life history requirements of Gunnison sage-grouse in the majority
of the Gunnison Basin. Only 40 percent of the allotments in the San
Miguel population were meeting LHA objectives. This data suggests that
regulatory mechanisms applied within livestock grazing permits and
leases are not being implemented such that they ensure that habitats
within two of the largest Gunnison sage-grouse populations are making
significant progress toward being restored or maintained for Gunnison
sage-grouse.
USFS
The USFS manages 10 percent of the occupied Gunnison sage-grouse
habitat (Table 1). Management of National Forest System lands is guided
principally by the National Forest Management Act (NFMA) (16 U.S.C.
1600-1614, August 17, 1974, as amended). The NFMA specifies that all
National Forests must have a Land and Resource Management Plan (LRMP)
(16 U.S.C. 1600) to guide and set standards for all natural resource
management activities on each National Forest or National Grassland.
The NFMA requires USFS to incorporate standards and guidelines into
LRMPs (16 U.S.C. 1600). USFS conducts NEPA analysis on its LRMPs, which
include provisions to manage plant and animal communities for
diversity, based on the suitability and capability of the specific land
area in order to meet overall multiple-use objectives. The USFS
planning process is similar to that of BLM.
The Gunnison sage-grouse is a USFS sensitive species in both Region
2 (Colorado) and Region 4 (Utah). USFS policy provides direction to
analyze potential impacts of proposed management activities to
sensitive species in a biological evaluation. The forests within the
range of sage-grouse provide important seasonal habitats for the
species, particularly the Grand Mesa, Uncompahgre, and Gunnison (GMUG)
National Forests. The 1991 Amended Land and Resource Management Plan
for the GMUG National Forests has not directly incorporated Gunnison
sage-grouse conservation measures or habitat objectives. The Regional
Forester signed the RCP and as such has agreed to follow and implement
those recommendations. Three of the 34 grazing allotments in occupied
grouse habitat have incorporated Gunnison sage-grouse habitat
objectives. To date USFS has not deferred or withdrawn oil and gas
leasing in occupied habitat, but sage-grouse conservation measures can
be included at the ``Application for Permit to Drill'' stage. The BLM,
which regulates oil and gas leases on USFS lands, has the authority to
defer leases.
[[Page 59843]]
However, the only population within USFS lands that is in areas of
high or even medium potential for oil and gas reserves is the San
Miguel Basin, and USFS lands only make up 1.4 percent of that
population (GSRSC 2005, D-8). While consideration as a sensitive
species and following the recommendations contained in the Gunnison
sage-grouse Rangewide Conservation Plan (GSRSC 2005, entire) can
provide some conservation benefits, they are voluntary in nature.
Considering the aforementioned, the USFS has minimal regulatory
authority that has been implemented to provide for the long-term
conservation of Gunnison sage-grouse and its habitat.
NPS
The NPS manages two percent of occupied Gunnison sage-grouse
habitat (Table 1), which means that there is little opportunity for the
agency to affect range-wide conservation of the species. The NPS
Organic Act (39 Stat. 535; 16 U.S.C. 1, 2, 3, and 4) states that NPS
will administer areas under their jurisdiction ``by such means and
measures as conform to the fundamental purpose of said parks,
monuments, and reservations, which purpose is to conserve the scenery
and the natural and historical objects and the wild life therein and to
provide for the enjoyment of the same in such manner and by such means
as will leave them unimpaired for the enjoyment of future
generations.'' Lands in the Black Canyon of the Gunnison National Park
and the Curecanti National Recreation Area include portions of occupied
habitat of the Crawford and Gunnison Basin populations. The 1993 Black
Canyon of the Gunnison Resource Management Plan (NPS 1993, entire) and
the 1995 Curecanti National Recreation Area Resource Management Plan
(NPS 1995, entire) do not identify any specific conservation measures
for Gunnison sage-grouse. However, these Resource Management Plans are
outdated and will be replaced with Resource Stewardship Strategies,
which will be developed in the next five to seven years. In the mean
time, NPS ability to actively manage for species of special concern is
not limited by the scope of their management plans.
NPS completed a Fire Management Plan in 2006 (NPS 2006, entire).
Both prescribed fire and fire use (allowing wildfires to burn) are
identified as a suitable use in Gunnison sage-grouse habitat. However,
Gunnison sage-grouse habitat is identified as a Category C area,
meaning that while fire is a desirable component of the ecosystem,
ecological constraints must be observed. For Gunnison sage-grouse,
constraints include limitation of acreage burned per year and
limitation of percent of project polygons burned. The NPS is currently
following conservation measures in the local conservation plans and the
RCP (Stahlnecker 2010, pers. comm.).
In most cases, implementation of NPS fire management policies
should result in minimal adverse effects since emphasis is placed on
activities that will minimize, or ideally benefit, impacts to Gunnison
sage-grouse habitat. Overall, implementation of NPS regulations should
minimize impacts to Gunnison sage-grouse. Certain activities, such as
human recreation activities occurring within occupied habitat, may have
adverse effects, although we believe the limited nature of such
activities on NPS lands would limit their impacts on the species and
thus not be considered a threat to Gunnison sage-grouse. Grazing
management activities on NPS lands are governed by BLM regulations and
their implementation.
Summary of Factor D
Gunnison sage-grouse conservation has been addressed in some local,
State, and Federal plans, laws, regulations, and policies. Gunnison
County has implemented regulatory authority over development within
their area of jurisdiction, for which they are to be highly commended.
No other counties within the range of the species have implemented such
regulations. While regulations implemented in Gunnison County have
minimized some impacts, it has not curtailed the habitat loss,
fragmentation, and degradation occurring within the County's
jurisidictional boundary. Due to the limited scope and applicability of
these regulations throughout the range of the species and within all
populations, the current local land use or development planning
regulations do not provide adequate regulatory authority to protect
sage-grouse from development or other harmful land uses that result in
habitat loss, degradation, and fragmentation. The CDOW and UDWR have
implemented and continue to pursue conservation easements in Colorado
and Utah, respectively, to conserve Gunnison sage-grouse habitat and
meet the species' needs. These easements provide protection for the
species where they occur, but do not cover enough of the landscape to
provide for long-term conservation of the species. State wildlife
regulations provide protection for individual Gunnison sage-grouse from
direct mortality due to hunting but do not protect its habitat from the
main threat of loss and fragmentation. Our assessment of the
implementation of regulations and associated stipulations guiding
exurban development indicates that current regulatory measures do not
adequately ameliorate impacts to sage-grouse and its habitat.
Energy development is only considered a threat in the Dry Creek
Basin subpopulation of the San Miguel population. For the BLM and USFS,
RMPs and LRMPs are mechanisms through which adequate and enforceable
protections for Gunnison sage-grouse could be implemented. However, the
extent to which appropriate measures to reduce or eliminate threats to
sage-grouse resulting from the various activites the agencies manage
have been incorporated into those planning documents, or are being
implemented, vary across the range. As evidenced by the discussion
above, and the ongoing threats described under Factor A, BLM and the
USFS are not fully implementing the regulatory mechanisms available to
conserve Gunnison sage-grouse and their habitats on their lands.
We have evaluated the best available scientific information on the
adequacy of regulatory mechanisms to address threats to Gunnison sage-
grouse and its habitats. While 54 percent of Gunnison sage-grouse
habitat is managed by Federal agencies, these lands are interspersed
with private lands, which do not have adequate regulatory mechanisms to
ameliorate the further loss and fragmentation of habitat in all
populations. This interspersion of private lands throughout Federal and
other public lands extends the negative influence of those activities
beyond the actual 41 percent of occupied habitat that private lands
overlay. While we are unable to quantify the extent of the impacts on
Federal lands resulting from activities on private lands, we have
determined that the inadequacy of regulatory mechanisms on private
lands as they pertain to human infrastructure development and the
inadequate implementation of Federal authorities on some Federal lands
pose a significant threat to the species throughout its range. Further,
the threat of inadequate regulatory mechanisms is expected to continue
or even increase in the future.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Other factors potentially affecting the Gunnison sage-grouse's
continued existence include genetic risks, drought, recreational
activities, pesticides and herbicides, and contaminants.
[[Page 59844]]
Genetics and Small Population Size
Small populations face three primary genetic risks: inbreeding
depression; loss of genetic variation; and accumulation of new
mutations. Inbreeding can have individual and population consequences
by either increasing the phenotypic expression of recessive,
deleterious alleles (the expression of harmful genes through the
physical appearance) or by reducing the overall fitness of individuals
in the population (GSRSC 2005, p.109 and references therein). At the
species level, Gunnison sage-grouse have low levels of genetic
diversity particularly when compared to greater sage-grouse (Oyler-
McCance et al. 2005, p. 635). There is no consensus regarding how large
a population must be in order to prevent inbreeding depression.
However, the San Miguel Basin Gunnison sage-grouse effective population
size was below the level at which inbreeding depression has been
observed to occur (Stiver et al. 2008, p. 479). Lowered hatching
success is a well documented correlate of inbreeding in wild bird
populations (Stiver et al. 2008, p. 479 and references therein). Stiver
et al. (2008, p. 479) suggested the observed lowered hatching success
rate of Gunnison sage-grouse in their study may be caused by inbreeding
depression. Similarities of hatchability rates exist among other bird
species that had undergone genetic bottlenecks. The application of the
same procedures of effective population size estimation as used for the
San Miguel Basin to the other Gunnison sage-grouse populations
indicated that all populations other than the Gunnison Basin population
may have population sizes low enough to induce inbreeding depression;
and all populations could be losing adaptive potential (Stiver et al.
2008, p. 479).
Population structure of Gunnison sage-grouse was investigated using
mitochondrial DNA sequence (mtDNA, maternally inherited DNA located in
cellular organelles called mitochondria) and nuclear microsatellite
data from seven geographic areas (Cerro Summit-Cimarron-Sims Mesa,
Crawford, Gunnison Basin, Curecanti area of the Gunnison Basin,
Monticello-Dove Creek, Pinon Mesa, and San Miguel Basin) (Oyler-McCance
et al. 2005, entire). The Cerro Summit-Cimarron-Sims Mesa population
was not included in the analysis due to inadequate sample sizes. The
Poncha Pass population also was not included as it is composed of
individuals transplanted from Gunnison Basin. Oyler-McCance et al.
(2005, entire) found that levels of genetic diversity were highest in
the Gunnison Basin, which consistently had more alleles and most of the
alleles present in other populations. All other populations had much
lower levels of diversity.
The lower diversity levels are linked to small population sizes and
a high degree of geographic isolation. Collectively, the smaller
populations contain 24 percent of the genetic diversity of the species.
Individually, each of the small populations may not be important
genetically to the survival of the species, but collectively it is
likely that 24 percent of the genetic diversity is important to future
rangewide survival of the species. Some of the genetic makeup contained
within the smaller populations (with the potential exception of the
Poncha Pass population since it consists of birds from the Gunnison
Basin) may be critical to maintaining adaptability in the face of
issues such as climate change or other environmental change. All
populations sampled were found to be genetically discrete units (Oyler-
McCance et al. 2005, p. 635), so the loss of any of them would result
in a decrease in genetic diversity of the species. In addition,
multiple populations across a broad geographic area provide insurance
against a single catastrophic event (such as the effects of a
significant drought even), and the aggregate number of individuals
across all populations increases the probability of demographic
persistence and preservation of overall genetic diversity by providing
an important genetic reservoir (GSRSC 2005, p. 179). Consequently, the
loss of any one population would have a negative effect on the species
as a whole.
Historically, the Monticello-Dove Creek, San Miguel, Crawford, and
Pinon Mesa populations were larger and were connected through more
contiguous areas of sagebrush habitat. A 20 percent loss of habitat and
37 percent fragmentation of sagebrush habitat was documented in
southwestern Colorado between the late 1950s and the early 1990s
(Oyler-McCance et al. 2001, p.), which led to the current isolation of
these populations and is consistent with the documented low amounts of
gene flow and isolation by distance (Oyler-McCance et al. 2005, p.
635). However, Oyler-McCance et al. (2005, p. 636) noted that a few
individuals in their analysis appeared to have the genetic
characteristics of a population other than their own, suggesting they
were dispersers from a different population. Two probable dispersers
were individuals moving from San Miguel into Monticello-Dove Creek and
Crawford. The San Miguel population itself appeared to have a mixture
of individuals with differing probabilities of belonging to different
clusters. This information suggests that the San Miguel population may
act as a conduit of gene flow among the satellite populations
surrounding the larger Gunnison Basin population. Additionally, another
potential disperser into Crawford was found from the Gunnison Basin
(Oyler-McCance et al. 2005, p. 636). This result is not surprising
given their close geographic proximity.
Effective population size (Ne) is an important parameter in
conservation biology. It is defined as the size of an idealized
population of breeding adults that would experience the same rate of
(1) loss of heterozygosity (the amount and number of different genes
within individuals in a population), (2) change in the average
inbreeding coefficient (a calculation of the amount of breeding by
closely related individuals), or (3) change in variance in allele (one
member if a pair or series of genes occupying a specific position in a
specific chromosome) frequency through genetic drift (the fluctuation
in gene frequency occurring in an isolated population) as the actual
population. The effective size of a population is often much less than
its actual size or number of individuals. As effective population size
decreases, the rate of loss of allelic diversity via genetic drift
increases. Two consequences of this loss of genetic diversity, reduced
fitness through inbreeding depression and reduced response to sustained
directional selection (``adaptive potential''), are thought to elevate
extinction risk (Stiver et al., 2008, p. 472 and references therein).
While no consensus exists on the population size needed to retain a
level of genetic diversity that maximizes evolutionary potential (i.e.,
the ability to adapt to local changes), up to 5,000 greater sage-grouse
may be necessary to maintain an effective population size of 500 birds
(Aldridge and Brigham, 2003, p. 30). Other recent recommendations also
suggest populations of at least 5,000 individuals to deal with
evolutionary and demographic constraints (Trail et al. 2009, in press,
p. 3, and references therein). While the persistence of wild
populations is usually influenced more by ecological rather than by
genetic effects, once they are reduced in size, genetic factors become
increasingly important (Lande 1995, p. 318).
The CDOW contracted for a population viability analysis (PVA) for
the Gunnison sage-grouse (GSRSC 2005, Appendix G). The purpose of the
Gunnison sage-grouse PVA was to assist
[[Page 59845]]
the CDOW in evaluating the relative risk of extinction for each
population under the conditions at that time (i.e., the risk of
extinction if nothing changed), to estimate relative extinction
probabilities and loss of genetic diversity over time for various
population sizes, and to determine the sensitivity of Gunnison sage-
grouse population growth rates to various demographic parameters (GSRSC
2005, p. 169). The PVA was used as a tool to predict the relative, not
absolute or precise, probability of extinction for the different
populations under various management scenarios based on information
available at that time and with the understanding that no data were
available to determine how demographic rates would be affected by
habitat loss or fragmentation. The analysis indicated that small
populations (< 50 birds) are at a serious risk of extinction within the
next 50 years (assuming some degree of consistency of environmental
influences in sage-grouse demography). In contrast, populations in
excess of 500 birds had an extinction risk of less than 5 percent
within the same time period. These results suggested that the Gunnison
Basin population is likely to persist long term in the absence of
threats acting on it. In the absence of intervention, the Cerro Summit-
Cimarron-Sims Mesa and Poncha Pass populations and the Dove Creek group
of the Monticello-Dove Creek population were likely to become
extirpated (GSRSC 2005, pp. 168-179). Based on 2009 population
estimates and an overall declining population trend, the same three
populations may soon be extirpated. Additionally, Gunnison sage-grouse
estimates in the Crawford and Pinon Mesa populations have declined by
over 50 percent since the PVA was conducted (Table 2), so they too are
likely trending towards extirpation. The San Miguel population has
declined by 40 percent since 2004, so cumulative factors may be
combining to cause its future extirpation also.
The lack of large expanses of sagebrush habitat required by
Gunnison sage-grouse in at least six of the seven Gunnison sage-grouse
populations (as discussed in Factor A), combined with the results of
the PVA and current population trends suggest that at least five, and
most likely six, of the seven Gunnison sage-grouse populations are at
high risk of extirpation. The loss of genetic diversity from the
extirpation of the aforementioned populations would result in a loss of
genetic diversity of the species as a whole and thus contribute to
decreased functionality of these remaining populations in maintaining
viability and adaptability, as well as the contribution of these
populations to connectivity and the continued existence of the entire
species.
Six of the seven Gunnison sage-grouse populations may have
effective sizes low enough to induce inbreeding depression and all
seven could be losing adaptive potential, with the assumption that the
five populations smaller than the San Miguel population are exhibiting
similar demography to the San Miguel population (Stiver et al. 2008, p.
479) and thus trending towards extirpation. Stiver et al. (2008, p.
479) suggested that long-term persistence of the six smaller
populations would require translocations to supplement genetic
diversity. The only population currently providing individuals to be
translocated is the Gunnison Basin population, but because of
substantial population declines such as those observed between the 2001
and 2004 lek counts (Stiver et al., 2008, p. 479), significant
questions arise as to whether this population would be able to sustain
the loss of individuals required by translocations. Lek counts, and
consequently population estimates, especially in the San Miguel Basin
and Gunnison Basin populations, have undergone substantial declines
(Table 2) since peaks observed in the annual 2004 and 2005 counts, thus
making inbreeding depression even more likely to be occurring within
all populations except the Gunnison Basin. While we recognize that
sage-grouse population sizes are cyclical, and that there are concerns
about the statistical reliability of lek counts and the resulting
population estimates (CDOW 2009a, pp. 1-3), we nonetheless believe that
the overall declining trends of 6 of the 7 Gunnison sage-grouse
populations, and for the species as a whole, are such that they are
having a significant impact on the species' ability to persist.
In summary, the declines in estimates of grouse numbers since 2005
are likely to contribute to even lower levels of genetic diversity and
higher levels of inbreeding depression than previously considered, thus
making the species as a whole less adaptable to environmental variables
and more vulnerable to extirpation. Based on the information presented
above, we have determined that genetic risks related to the small
population size of Gunnison sage-grouse are a threat to the species now
and in the foreseeable future.
Drought
Drought is a common occurrence throughout the range of the Gunnison
and greater sage-grouse (Braun 1998, p. 148) and is considered a
universal ecological driver across the Great Plains (Knopf 1996,
p.147). Infrequent, severe drought may cause local extinctions of
annual forbs and grasses that have invaded stands of perennial species,
and recolonization of these areas by native species may be slow (Tilman
and El Haddi 1992, p. 263). Drought reduces vegetation cover (Milton et
al. 1994, p. 75; Connelly et al. 2004, p. 7-18), potentially resulting
in increased soil erosion and subsequent reduced soil depths, decreased
water infiltration, and reduced water storage capacity. Drought also
can exacerbate other natural events such as defoliation of sagebrush by
insects. For example, approximately 2,544 km\2\ (982 mi\2\) of
sagebrush shrublands died in Utah in 2003 as a result of drought and
infestations with the Aroga (webworm) moth (Connelly et al. 2004, p. 5-
11). Sage-grouse are affected by drought through the loss of vegetative
habitat components, reduced insect production (Connelly and Braun 1997,
p. 9), and potential increased risk of virus infections, such as the
West Nile virus. These habitat component losses can result in declining
sage-grouse populations due to increased nest predation and early brood
mortality associated with decreased nest cover and food availability
(Braun 1998, p. 149; Moynahan et al. 2007, p. 1781).
Greater sage-grouse populations declined during the 1930s period of
drought (Patterson 1952, pp. 68-69; Braun 1998, p. 148). Drought
conditions in the late 1980s and early 1990s also coincided with a
period when sage-grouse populations were at historically low levels
(Connelly and Braun 1997, p. 8). Although drought has been a consistent
and natural part of the sagebrush-steppe ecosystem, drought impacts on
sage-grouse can be exacerbated when combined with other habitat
impacts, such as human developments, that reduce cover and food (Braun
1998, p. 148).
Aldridge et al. (2008, p. 992) found that the number of severe
droughts from 1950 to 2003 had a weak negative effect on patterns of
greater sage-grouse persistence. However, they cautioned that drought
may have a greater influence on future sage-grouse populations as
temperatures rise over the next 50 years, and synergistic effects of
other threats affect habitat quality (Aldridge et al. 2008, p. 992).
Populations on the periphery of the range may suffer extirpation during
a severe and prolonged drought (Wisdom et al. in press, p. 22).
Gunnison sage-grouse are capable of enduring moderate or severe,
but relatively short-term, drought as observed from persistence of the
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populations during drought conditions from 1999-2003 throughout much of
the range. The drought that began by at least 2001 and was most severe
in 2002 had varying impacts on Gunnison sage-grouse habitat and is
discussed in detail in our April 18, 2006, finding (71 FR 19954).
Habitat appeared to be negatively affected by drought across a broad
area of the Gunnison sage-grouse's range. However, the reduction of
sagebrush density in some areas, allowing for greater herbaceous growth
and stimulating the onset of sagebrush seed crops may have been
beneficial to sagebrush habitats over the long term. Six of the seven
grouse populations (except for the Gunnison Basin population) have
decreased in number since counts were conducted during the drought year
of 2002 (Table 2). Data are not available to scientifically determine
if the declines are due to the drought alone. The current status of the
various populations throughout the species' range make it highly
susceptible to stochastic factors such as drought, particularly when it
is acting in conjunction with other factors such as habitat
fragmentation, small population size, predation, and low genetic
diversity. We believe that the available information is too speculative
to conclude that drought alone is a threat to the species at this time;
however, based on rapid species decline in drought years, it is likely
that drought exacerbates other known threats and thus is an indirect
threat to the species.
Recreation
Studies have determined that nonconsumptive recreational activities
can degrade wildlife resources, water, and the land by distributing
refuse, disturbing and displacing wildlife, increasing animal
mortality, and simplifying plant communities (Boyle and Samson 1985,
pp. 110-112). Sage-grouse response to disturbance may be influenced by
the type of activity, recreationist behavior, predictability of
activity, frequency and magnitude, timing, and activity location
(Knight and Cole 1995, p. 71). We have not located any published
literature concerning measured direct effects of recreational
activities on Gunnison or greater sage-grouse, but can infer potential
impacts on Gunnison sage-grouse from studies on related species and
from research on nonrecreational activities. Baydack and Hein (1987, p.
537) reported displacement of male sharp-tailed grouse at leks from
human presence resulting in loss of reproductive opportunity during the
disturbance period. Female sharp-tailed grouse were observed at
undisturbed leks while absent from disturbed leks during the same time
period (Baydack and Hein 1987, p. 537). Disturbance of incubating
female sage-grouse could cause displacement from nests, increased
predator risk, or loss of nests. Disruption of sage-grouse during
vulnerable periods at leks, or during nesting or early brood rearing
could affect reproduction or survival (Baydack and Hein 1987, pp. 537-
538).
Recreational use of off-highway vehicles (OHVs) is one of the
fastest-growing outdoor activities. In the western United States,
greater than 27 percent of the human population used OHVs for
recreational activities between 1999 and 2004 (Knick et al., in press,
p. 19). Knick et al. (in press, p. 1) reported that widespread
motorized access for recreation facilitated the spread of predators
adapted to humans and the spread of invasive plants. Any high-frequency
human activity along established corridors can affect wildlife through
habitat loss and fragmentation (Knick et al. in press, p. 25). The
effects of OHV use on sagebrush and sage-grouse have not been directly
studied (Knick et al. in press, p. 25). However, local working groups
considered recreational uses, such as off-road vehicle use and biking,
to be a risk factor in many areas.
Recreation from OHVs, hikers, mountain bikes, campers, snowmobiles,
bird watchers, and other sources has affected many parts of the range,
especially portions of the Gunnison Basin and Pinon Mesa population
(BLM 2005a, p. 14; BLM 2005d, p. 4; BLM 2009, p. 36). These activities
can result in abandonment of lekking activities and nest sites, energy
expenditure reducing survival, and greater exposure to predators (GSRSC
2005).
Recreation is a significant use on lands managed by BLM (Connelly
et al. 2004, p. 7-26). Recreational activities within the Gunnison
Basin are widespread, occur during all seasons of the year, and have
expanded as more people move to the area or come to recreate (BLM 2009,
pp. 36-37). Four wheel drive, OHV, motorcycle, and other means of
mechanized travel have been increasing rapidly. The number of annual
OHV registrations in Colorado increased from 12,000 in 1991 to 131,000
in 2007 (BLM 2009, p. 37). Recreational activities are recognized as a
direct and indirect threat to the Gunnison sage-grouse and their
habitat (BLM 2009, p. 36). The Grand Mesa, Uncompaghre, and Gunnison
(GMUG) National Forest is the fourth most visited National Forest in
the Rocky Mountain Region of the USFS (Region 2) (Kocis et al., 2004 in
Draft Environmental Impact Statement for Gunnison Basin Federal Lands
Travel Management (2009, p. 137)). The GMUG is the second most heavily
visited National Forest on the western slope of Colorado (DEIS Gunnison
Basin Federal Lands Travel Management 2009, p. 137). However, it is
unknown what percentage of the visits occur within Gunnison sage-grouse
habitat on the Gunnison Ranger District ((DEIS Gunnison Basin Federal
Lands Travel Management 2009, p. 137). With human populations expected
to increase in towns and cities within and adjacent to the Gunnison
Basin and nearby populations (see Factor A), we believe the impacts to
Gunnison sage-grouse from recreational use will continue to increase.
The BLM and Gunnison County have 38 closure points within the Basin
from March 15 to May 15 each year (BLM 2009, p. 40). While road
closures may be violated in a small number of situations, we believe
that road closures are having a beneficial effect on Gunnison sage-
grouse through avoidance and/or minimization of impacts during the
breeding season.
Dispersed camping occurs at a low level on public lands in all of
the populations, particularly during the hunting seasons for other
species. However, we have no information indicating that these camping
activities are adversely affecting Gunnison sage-grouse.
Domestic dogs accompanying recreationists or associated with
residences can disturb, harass, displace, or kill Gunnison sage-grouse.
Authors of many wildlife disturbance studies concluded that dogs with
people, dogs on leash, or loose dogs provoked the most pronounced
disturbance reactions from their study animals (Sime 1999 and
references within). The primary consequences of dogs being off leash is
harassment, which can lead to physiological stress as well as the
separation of adult and young birds, or flushing incubating birds from
their nest. However, we have no data indicating that this activity is
adversely affecting Gunnison sage-grouse population numbers such that
it can be considered a rangewide or population-level threat.
Recreational activities as discussed above do not singularly pose a
significant threat to Gunnison sage-grouse now or are expected to do so
in the foreseeable future. However, there may be certain situations
where recreational activities are impacting local concentrations of
Gunnison sage-grouse, especially in areas where habitat is already
fragmented such as in the six
[[Page 59847]]
small populations and in certain areas within the Gunnison Basin.
Pesticides and Herbicides
Insects are an important component of sage-grouse chick and
juvenile diets (GSRSC 2005, p.132 and references therein). Insects,
especially ants (Hymenoptera) and beetles (Coleoptera), can comprise a
major proportion of the diet of juvenile sage-grouse and are important
components of early brood-rearing habitats (GSRSC 2005, p. 132 and
references therein). Most pesticide applications are not directed at
control of ants and beetles. Pesticides are used primarily to control
insects causing damage to cultivated crops on private lands and to
control grasshoppers (Orthoptera) and Mormon crickets (Mormonius sp.)
on public lands.
Few studies have examined the effects of pesticides to sage-grouse,
but at least two have documented direct mortality of greater sage-
grouse from use of these chemicals. Greater sage-grouse died as a
result of ingestion of alfalfa sprayed with organophosphorus
insecticides (Blus et al. 1989, p. 1142; Blus and Connelly 1998, p.
23). In this case, a field of alfalfa was sprayed with methamidophos
and dimethoate when approximately 200 greater sage-grouse were present;
63 of these sage-grouse were later found dead, presumably as a result
of pesticide exposure (Blus et al. 1989; p. 1142, Blus and Connelly
1998, p. 23). Both methamidophos and dimethoate remain registered for
use in the United States (Christiansen and Tate in press, p. 21), but
we found no further records of sage-grouse mortalities from their use.
In 1950, rangelands treated with toxaphene and chlordane bait to
control grasshoppers in Wyoming resulted in game bird mortality of 23.4
percent (Christian and Tate in press, p. 20). Forty-five greater sage-
grouse deaths were recorded, 11 of which were most likely related to
the pesticide (Christiansen and Tate in press, p. 20, and references
therein). Greater sage-grouse who succumbed to vehicle collisions and
mowing machines in the same area also were likely compromised from
pesticide ingestion (Christian and Tate in press, p. 20). Neither of
these chemicals has been registered for grasshopper control since the
early 1980s (Christiansen and Tate in press, p. 20, and references
therein).
Infestations of Russian wheat aphids (Diuraphis noxia) have
occurred in Gunnison sage-grouse occupied range in Colorado and Utah
(GSRSC 2005, p. 132). Disulfoton, a systemic organophosphate extremely
toxic to wildlife, was routinely applied to over 400,000 ha (million
ac) of winter wheat crops to control the aphids during the late 1980s.
We have no data indicating there were any adverse effects to Gunnison
sage-grouse (GSRSC 2005, p. 132). More recently, an infestation of army
cutworms (Euxoa auxiliaries) occurred in Gunnison sage-grouse habitat
along the Utah-Colorado State line. Thousands of ha (thousands of ac)
of winter wheat and alfalfa fields were sprayed with insecticides such
as permethrin by private landowners to control them (GSRSC 2005, p.
132) but again, we have no data indicating any adverse effects to
Gunnison sage-grouse.
Game birds that ingested sublethal levels of pesticides have been
observed exhibiting abnormal behavior that may lead to a greater risk
of predation (Dahlen and Haugen 1954, p. 477; McEwen and Brown 1966, p.
609; Blus et al. 1989, p. 1141). McEwen and Brown (1966, p. 689)
reported that wild sharp-tailed grouse poisoned by malathion and
dieldrin exhibited depression, dullness, slowed reactions, irregular
flight, and uncoordinated walking. Although no research has explicitly
studied the indirect levels of mortality from sublethal doses of
pesticides (e.g., predation of impaired birds), it has been assumed to
be the reason for mortality among some study birds (McEwen and Brown
1966 p. 609; Blus et al. 1989, p. 1142; Connelly and Blus 1991, p. 4).
Both Post (1951, p. 383) and Blus et al. (1989, p. 1142) located
depredated sage-grouse carcasses in areas that had been treated with
insecticides. Exposure to these insecticides may have predisposed sage-
grouse to predation. Sage-grouse mortalities also were documented in a
study where they were exposed to strychnine bait used to control small
mammals (Ward et al. 1942 as cited in Schroeder et al. 1999, p. 16).
While we do not have specific information of these effects occurring in
Gunnison sage-grouse, we believe the effects observed in greater sage-
grouse can be expected if similar situations arise within Gunnison
sage-grouse habitat.
Cropland spraying may affect populations that are not adjacent to
agricultural areas, given the distances traveled by females with broods
from nesting areas to late brood-rearing areas (Knick et al. in press,
p. 17). The actual footprint of this effect cannot be estimated,
because the distances sage-grouse travel to get to irrigated and
sprayed fields is unknown (Knick et al. in press, p. 17). Similarly,
actual mortalities from pesticides may be underestimated if sage-grouse
disperse from agricultural areas after exposure.
Much of the research related to pesticides that had either lethal
or sublethal effects on greater sage-grouse was conducted on pesticides
that have been banned or have had their use further restricted for more
than 20 years due to their toxic effects on the environment (e.g.,
dieldrin). We currently do not have any information to show that the
banned pesticides are having negative impacts to sage-grouse
populations through either illegal use or residues in the environment.
For example, sage-grouse mortalities were documented in a study where
they were exposed to strychnine bait used to control small mammals
(Ward et al. 1942 as cited in Schroeder et al. 1999, p. 16). According
to the U.S. Environmental Protection Agency (EPA), above-ground uses of
strychnine were prohibited in 1988 and those uses remain temporarily
cancelled today. We do not know when, or if, above-ground uses will be
permitted to resume. Currently, strychnine is registered for use only
below-ground as a bait application to control pocket gophers (Thomomys
sp.; EPA 1996, p. 4). Therefore, the current legal use of strychnine
baits is unlikely to present a significant exposure risk to sage-
grouse. No information on illegal use, if it occurs, is available. We
have no other information regarding mortalities or sublethal effects of
strychnine or other banned pesticides on sage-grouse.
Although a reduction in insect population levels resulting from
insecticide application can potentially affect nesting sage-grouse
females and chicks (Willis et al. 1993, p. 40; Schroeder et al. 1999,
p. 16), there is no information as to whether insecticides are
impacting survivorship or productivity of the Gunnison sage-grouse.
Herbicide applications can kill sagebrush and forbs important as
food sources for sage-grouse (Carr 1968 in Call and Maser 1985, p. 14).
The greatest impact resulting from a reduction of either forbs or
insect populations is to nesting females and chicks due to the loss of
potential protein sources that are critical for successful egg
production and chick nutrition (Johnson and Boyce 1991, p. 90;
Schroeder et al. 1999, p. 16). A comparison of applied levels of
herbicides with toxicity studies of grouse, chickens, and other
gamebirds (Carr 1968, in Call and Maser 1985, p. 15) concluded that
herbicides applied at recommended rates should not result in sage-
grouse poisonings.
Use of insecticides to control mosquitoes is infrequent and
probably does not have detrimental effects on sage-grouse. Available
insecticides that kill adult mosquitoes include synthetic pyrethroids
such as permethrin, which
[[Page 59848]]
are applied at very low concentrations and have very low vertebrate
toxicity (Rose 2004). Organophosphates such as malathion have been used
at very low rates to kill adult mosquitoes for decades, and are judged
relatively safe for vertebrates (Rose 2004).
In summary, historically insecticides have been shown to result in
direct mortality of individuals, and also can reduce the availability
of food sources, which in turn could contribute to mortality of sage-
grouse. Despite the potential effects of pesticides, we could find no
information to indicate that the use of these chemicals, at current
levels, negatively affects Gunnison sage-grouse population numbers.
Schroeder et al.'s (1999, p. 16) literature review found that the loss
of insects can have significant impacts on nesting females and chicks,
but those impacts were not detailed. Many of the pesticides that have
been shown to have an effect on sage-grouse have been banned in the
United States for more than 20 years. We currently do not have any
information to show that either the illegal use of banned pesticides or
residues in the environment are presently having negative impacts to
sage-grouse populations. While the reduction in insect availability via
insecticide application has not been documented to affect overall
population numbers in sage-grouse, we believe that insect reduction,
because of its importance to chick production and survival, could be
having as yet undetected negative impacts in populations with low
population numbers. There is no information available to indicate that
either herbicide or insecticide applications pose a threat to the
species now or in the foreseeable future.
Contaminants
Gunnison sage-grouse exposure to various types of environmental
contaminants may potentially occur as a result of agricultural and
rangeland management practices, mining, energy development and pipeline
operations, and transportation of materials along highways and
railroads.
We expect that the number of sage-grouse occurring in the immediate
vicinity of wastewater pits associated with energy development would be
small due to the small amount of energy development within the species'
range, the typically intense human activity in these areas, the lack of
cover around the pits, and the fact that sage-grouse do not require
free water. Most bird mortalities recorded in association with
wastewater pits are water-dependent species (e.g., waterfowl), whereas
dead ground-dwelling birds (such as the sage-grouse) are rarely found
at such sites (Domenici 2008, pers. comm.). However, if the wastewater
pits are not appropriately screened, sage-grouse may have access to
them and could ingest water and become oiled while pursing insects. If
these birds then return to sagebrush cover and die, their carcasses are
unlikely to be found as only the pits are surveyed.
A few gas and oil pipelines occur within the San Miguel population.
Exposure to oil or gas from pipeline spills or leaks could cause
mortalities or morbidity to Gunnison sage-grouse. Similarly, given the
network of highways and railroad lines that occur throughout the range
of the Gunnison sage-grouse, there is some potential for exposure to
contaminants resulting from spills or leaks of hazardous materials
being conveyed along these transportation corridors. We found no
documented occurrences of impacts to Gunnison sage-grouse from such
spills, and we do not expect they are a significant source of mortality
and a threat to the species because these types of spills occur
infrequently and may involve only a small area within the occupied
range of the species.
Summary of Factor E
Although genetic consequences of low Gunnison sage-grouse
population numbers have not been definitively detected to date, the
results from Stiver et al. (2008, p. 479) suggest that six of the seven
populations may have effective sizes low enough to induce inbreeding
depression and all seven could be losing adaptive potential. While some
of these consequences may be ameliorated by translocations, we believe
the long-term viability of Gunnison sage-grouse is compromised by this
situation, particularly when combined with threats discussed under
other Factors, and we have determined that genetics risks related to
the small population size of Gunnison sage-grouse are a threat to the
species now and in the foreseeable future.
While sage-grouse have evolved with drought, population numbers
suggest that drought is at least correlated with, and potentially an
underlying cause of, the declines. Although we cannot determine whether
drought alone is a threat to the species, we believe it is an indirect
threat exacerbating other threat factors such as predation or habitat
fragmentation. Based on the available information, insecticides are
being used infrequently enough and in accordance with manufacturer
labeling such that they are not adversely affecting populations of the
Gunnison sage-grouse. The most likely impact of pesticides on Gunnison
sage-grouse is the reduction of insect prey items. However, we could
find no information to indicate that use of pesticides, in accordance
with their label instructions, is a threat to Gunnison sage-grouse.
Thus, based on the best scientific and commercial data available,
we have concluded that other natural or manmade factors are a
significant threat to the Gunnison sage-grouse.
Finding
We have carefully assessed the best scientific and commercial
information available regarding the present and future threats to the
Gunnison sage-grouse. We have reviewed the information available in our
files, information received during the comment period, and other
published and unpublished information, and consulted with recognized
Gunnison-sage grouse and sagebrush habitat experts. On the basis of the
best scientific and commercial information available, we find that
listing of the Gunnison sage-grouse is warranted throughout all of its
range.
Gunnison sage-grouse, a sagebrush obligate, are a landscape-scale
species requiring large, contiguous areas of sagebrush for long-term
persistence. Gunnison sage-grouse occur in seven isolated and
fragmented populations, primarily in southwestern Colorado, with a
small portion of its range extending into southeastern Utah.
Populations have been declining since the 1960s, with the Gunnison
Basin population the only relatively stable population. Six of the
seven remaining populations are now small enough to be vulnerable to
extirpation (Stiver et al. 2008, p. 479). Specific issues identified
under Factors A, C, D, and E are threats to the Gunnison sage-grouse.
These threats are exacerbated by small population sizes, the isolated
and fragmented nature of the remaining sagebrush habitat, and the
potential effects of climate change.
Current and future direct and functional loss of habitat due to
residential and road development in all populations (as discussed in
Factor A) is the principal threat to the Gunnison sage-grouse. Other
threats from human infrastructure such as fences and powerlines (as
discussed in Factor A) may not individually threaten the Gunnison sage-
grouse; however, the cumulative presence of these features,
particularly when considered with residential and road development, do
constitute a threat to the continued existence of the Gunnison sage-
grouse as they collectively contribute to habitat loss and
fragmentation. These impacts
[[Page 59849]]
exacerbate the fragmentation that has already occurred in Gunnison
sage-grouse habitat from past agricultural conversion and residential
development. Gunnison sage-grouse are sensitive to these forms of
habitat fragmentation because they require large areas of contiguous,
suitable habitat. Given the increasing human population trends in
Gunnison sage-grouse habitat, we expect urban and exurban development
and associated roads and infrastructure to continue to expand.
Likewise, we expect direct and indirect effects from these activities,
including habitat loss, degradation and fragmentation, to increase in
sage-grouse habitats.
Invasive species, fire, and climate change (as discussed in Factor
A) may not individually threaten the Gunnison sage-grouse; however, the
documented synergy among these factors result in a high likelihood that
they will threaten the species in the future. Noxious and invasive
plant incursions into sagebrush ecosystems, which are facilitated by
human activities and fragmentation, are likely to increase wildfire
frequencies, further contributing to direct loss of habitat and
fragmentation. Climate change may alter the range of invasive plants,
intensifying the proliferation of invasive plants to the point that
they become a threat to the species. While recent local climatic
moderations may have produced some improved habitat quality (increased
forb and grass growth providing enhanced grouse productivity and
survival). Habitat conservation efforts have been implemented to
benefit local habitat conditions, but they have not cumulatively
resulted in local population recoveries because unfragmented sagebrush
habitats on the scale required that contain the necessary ecological
attributes (e.g., connectivity and landscape context) have been lost.
Sagebrush habitats are highly fragmented due to anthropogenic impacts,
and in most cases are not resilient enough to return to native
vegetative states following disturbance from fire, invasive species,
and the effects of climate change. We expect these threats to continue
and potentially increase in magnitude in the future.
We found no evidence that the threats summarized above, which
contribute to habitat loss, degradation and fragmentation will subside
within the foreseeable future. Six populations are extremely small and
compromised by existing fragmentation. The one remaining relatively
contiguous patch of habitat (Gunnison Basin) for the species is
somewhat compromised by existing fragmentation. Based on the current
and anticipated habitat threats and their cumulative effects as they
contribute to the overall fragmentation of Gunnison sage-grouse
habitat, we have determined that threats identified under Factor A pose
a significant threat to the species throughout its range. We find that
the present or threatened destruction, modification, or curtailment of
Gunnison sage-grouse habitat is a threat to the species future
existence.
We believe that existing and continued landscape fragmentation will
increase the effects of predation (discussed in Factor C above) on this
species, particularly in the six smaller populations, resulting in a
reduction in sage-grouse productivity and abundance in the future.
Predation has a strong relationship with anthropogenic factors on the
landscape, and human presence on the landscape will continue to
increase in the future. We find that predation is a significant threat
to the species.
West Nile virus (discussed in Factor C above) is the only disease
that currently presents a potential threat to the Gunnison sage-grouse.
While we have no evidence of West Nile virus acting on the Gunnison
sage-grouse, because of the virus's presence within the species' range
and the continued development of anthropogenic water sources in the
area, the virus may pose a future threat to the species. We have
determined that disease is not currently a threat to the species.
However, we anticipate that West Nile virus will persist within the
range of Gunnison sage-grouse indefinitely and will be exacerbated by
factors such as climate change that could increase ambient temperatures
and the presence of the vector on the landscape.
An examination of regulatory mechanisms (discussed in Factor D
above) for both the Gunnison sage-grouse and sagebrush habitats
revealed that while limited mechanisms exist, they are not broad enough
in their potential conservation value throughout the species range, and
are not being implemented consistent with our current understanding of
the species' biology and reaction to disturbances, to be effective at
ameliorating threats. This is particularly true on private lands, which
comprise 41 percent of the species' extant range and are highly
dispersed throughout all populations. Inadequate regulation of grazing
practices on public land is occurring in some locations within the
species' range. Public land management agencies should continue to
improve habitat conditions to be compatible with Gunnison sage-grouse
life-history requirements. Some local conservation efforts are
effective and should be continued, but to date have occurred on a scale
that is too small to remove threats at a range-wide level. Many
conservation efforts lacked sufficient monitoring to demonstrate their
overall effectiveness in minimizing or eliminating the primary threat
of habitat loss, fragmentation, and degradation. Therefore, we find the
existing regulatory mechanisms are ineffective at ameliorating habitat-
based threats.
Small population size and genetic factors (discussed in Factor E
above) subject at least six of the seven populations to a high risk of
extirpation from stochastic events. All populations are currently
isolated as documented by low amounts of gene flow (Oyler-McCance et
al. 2005, p. 635). The loss of connectivity and the concomitant
isolation of the populations also increase the species' extinction
risk. Fitness and population size are strongly correlated, and smaller
populations are more subject to environmental and demographic
stochasticity. When coupled with mortality stressors related to human
activity and significant fluctuations in annual population size, long-
term persistence of small populations is always problematic. Given the
species' relatively low rate of growth and strong site fidelity,
recovery and repopulation of extirpated, or nearly extirpated areas,
will be extremely challenging. Translocation of Gunnison sage-grouse is
difficult and to date has not been demonstrated to be successful in
maintaining and improving population and species viability. Given the
limited number of source individuals, sustainable, successful
translocation efforts involving large numbers of individuals are
unlikely at this time. Recent captive-rearing efforts by CDOW have
provided some optimistic results. Nonetheless, even assuming CDOW
captive-rearing and tranlocation efforts prove to be successful in the
long-term, the existing condition of the habitat throughout the
species' range will need to be improved, before captive rearing and
translocation can be relied on to maintain population and species
viability.
The existing and continuing loss, degradation, and fragmentation of
sage-grouse habitat; extremely small population sizes; occupancy of
extremely small, isolated, and fragmented sagebrush areas; increased
susceptibility to predation; lack of interconnectivity; low genetic
diversity; and the potential for catastrophic stochastic (random)
events, combined with the inadequacy of existing regulations to manage
habitat loss (either direct or functional), endanger all Gunnison sage-
grouse populations
[[Page 59850]]
and the species as a whole. Threat factors affecting the Gunnison sage-
grouse are summarized in Table 5 below. As required by the Act, we have
reviewed and taken into account efforts being made to protect Gunnison
sage-grouse. Although some local conservation efforts have been
implemented and are effective in small areas, they are not at a scale
that is sufficient to ameliorate threats to the species as a whole.
Other conservation efforts (such as habitat treatments, establishment
of conservation easements, improved grazing practices, additional
travel management efforts that benefit Gunnison sage-grouse) are being
planned, but there is substantial uncertainty as to whether, where, and
when they will be implemented, and whether they will be effective.
[[Page 59851]]
Table 5. Threat summary for factors affecting Gunnison sage-grouse. A ``+'' indicates higher level of threat.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Magnitude Imminence
------------------------------------------------------------------------------------------ Species' Foreseeable
Listing Factor Threat or Impact Overall Exposure Overall Response Future Overall Threat
Magnitude Intensity (percent) Imminence Likelihood
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Conversion to Moderate Moderate 40% Non-Imminent Low Past conversion Year 2050\a\ Low
Agriculture contributes to
current habitat
fragmentation
and.
degradation.....
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Water Development Low Low <20% Non-Imminent Low Past development Year 2050 Low
contributes to
habitat.
fragmentation
and degradation.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Residential High+ High 70% Imminent High Habitat loss, Year 2050 High
Development fragmentation
and
degradation;
increased
predation.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Fences Moderate Low 75% Imminent High Habitat Year 2050 Moderate
fragmentation
and
degradation;
increased
predation;
direct
mortality
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Roads High+ High 90% Imminent High Habitat loss, Year 2050 High
fragmentation
and
degradation;
increased
predation;
direct
mortality.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Powerlines Moderate Moderate 60% Imminent High Habitat loss, Year 2050 Moderate+
fragmentation
and
degradation;
increased
predation.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Fire Low Low 10% Non-Imminent Low Habitat loss, Likely to Low+
fragmentation, increase.......
and degradation indefinitely...
with...........
cheatgrass.....
invasion.......
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Invasive Plants Moderate Moderate 65% Imminent Moderate Habitat loss, Likely to Moderate+
fragmentation, increase.......
and degradation indefinitely
due to.
increased human
presence and
climate change.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Pi[ntilde]on- Low Low 15% Imminent Moderate Habitat Indefinitely Low
Juniper fragmentation
Encroachment and
degradation;
increased
predation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Domestic and Wild High Low 85% Imminent Moderate Habitat Indefinitely Moderate
Ungulate Herbivory degradation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 59852]]
A Non-renewable Low+ Moderate 10% Imminent Low Habitat Year 2050 Low
Energy fragmentation
Development........ and
degradation;
increased
predation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Renewable Energy Low+ Low+ 15% Non-Imminent Moderate Habitat Year 2050 Low
Development fragmentation
and
degradation;
increased
predation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A Climate Change Low Moderate 100% Imminent Moderate Unknown, but Climate Low
could models.........
facilitate predict out to
increase in 40 years.
invasive plants
and
corresponding
increased fire..
frequency.......
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
B Hunting Low Low 0% Non-Imminent Low None Year 2050 Low
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
B Lek Viewing Low Low 10% Imminent Moderate Harassment; Year 2050 Low
avoidance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
B Scientific Research Low+ Low+ 50% Imminent Moderate Harassment; Year 2050 Low
direct
mortality
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
C Disease Low Low 100% Non-Imminent Moderate Direct mortality Indefinitely Low
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
C Predation High Moderate+ 90% Imminent High Direct mortality Indefinitely Moderate+
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
D Inadequacy of Local High Moderate 50% Imminent High Habitat loss, Year 2050 High
Laws and fragmentation,
Regulations........ and degradation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
D Inadequacy of State Moderate High 60% Imminent High Habitat loss, Year 2050 Moderate
Laws and fragmentation,
Regulations........ and degradation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
D Inadequacy of High High 75% Imminent High Habitat loss, Year 2050 High
Federal Laws and fragmentation,
Regulations and degradation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E Genetic High Moderate+ 70% Imminent High Inbreeding Indefinitely High
Complications depression;
loss of
adaptive
potential
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E Small Population Moderate+ Moderate+ 60% Imminent High Population Indefinitely Moderate+
Size vulnerability
to stochastic
events
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E Drought Moderate+ High 100% Imminent Moderate Habitat Indefinitely Moderate
degradation;
decline in
species
reproductive
potential
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E Recreation Low Low+ 50% Imminent Moderate Harassment; Year 2050 Low
avoidance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E Pesticides and Low Low 10% Non-Imminent Low Direct Year 2050 Low
Herbicides mortality;
habitat
degradation.....
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E Contaminants Low Low <5% Non-Imminent Low Direct mortality Year 2050 Low
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The foreseeable future date of 2050 was determined for threats or impacts directly related to anthropogenic activities based on the furthest population projection from CWCB (2009, p. 53).
[[Page 59853]]
Listing factors include: (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; or (E) other natural or manmade factors
affecting its continued existence.
We have carefully assessed the best scientific and commercial
information available regarding the present and future threats to the
Gunnison sage-grouse. We have reviewed petitions, information available
in our files, and other published and unpublished information, and
consulted with recognized Gunnison sage-grouse and greater sage-grouse
experts. We have considered and taken into account efforts being made
to conserve protect the species. On the basis of the best scientific
and commercial information available, we find that listing of the
Gunnison sage-grouse is warranted throughout all of its range. However,
listing the Gunnison sage-grouse is precluded by higher priority
listing actions at this time, as discussed in the Preclusion and
Expeditious Progress section below.
Listing Priority Number
The Service adopted guidelines on September 21, 1983 (48 FR 43098),
to establish a rational system for utilizing available resources for
the highest priority species when adding species to the Lists of
Endangered or Threatened Wildlife and Plants or reclassifying species
listed as threatened to endangered status. These guidelines, titled
``Endangered and Threatened Species Listing and Recovery Priority
Guidelines'' address the immediacy and magnitude of threats, and the
level of taxonomic distinctiveness by assigning priority in descending
order to monotypic genera (genus with one species), full species, and
subspecies (or equivalently, distinct population segments of
vertebrates).
As a result of our analysis of the best available scientific and
commercial information, we assigned the Gunnison sage-grouse an LPN of
2 based on our finding that the species faces threats that are of high
magnitude and are imminent. These threats include the present or
threatened destruction, modification, or curtailment of its habitat;
predation; the inadequacy of existing regulatory mechanisms; and other
natural or man-made factors affecting its continued existence. Our
rationale for assigning the Gunnison sage-grouse an LPN 2 is outlined
below.
Under the Service's LPN Guidance, the magnitude of threat is the
first criterion we look at when establishing a listing priority. The
guidance indicates that species with the highest magnitude of threat
are those species facing the greatest threats to their continued
existence. These species receive the highest listing priority. We
consider the threats that the Gunnison sage-grouse faces to be high in
magnitude because the major threats (exurban development, inadequacy of
regulatory mechanisms, genetic issues, roads) occur throughout all of
the species range. Based on an evaluation of biotic, abiotic, and
anthropogenic factors, no strongholds are believed to exist for
Gunnison sage-grouse (Wisdom et al., in press, entire). All seven
populations are experiencing habitat degradation and fragmentation due
to exurban development and roads. Six of the seven populations of
Gunnison sage-grouse currently contain so little occupied habitat that
continued degradation and fragmentation will place their continued
existence in question. The remaining population (Gunnison Basin) is so
interspersed with development and roads that it is likely to degrade
and fragment the habitat (Aldridge and Saher, in press, entire). We
believe it is not functional for a species that requires large expanses
of sagebrush. Six of the seven populations of Gunnison sage-grouse have
population sizes low enough to induce inbreeding depression, and all
seven may be losing their adaptive potential (Stiver 2008, p. 479).
Predation is exerting a strong influence on all populations, but
especially the six smaller populations. Invasive weeds are likely to
exert a strong influence on all populations in the future. Adequate
regulations are not in place at the local, State, or Federal level to
adequately minimize the threat of habitat degradation and fragmentation
resulting from exurban development. Regulatory mechanisms are not being
appropriately implemented such that land use practices result in
habitat conditions that adequately support the life-history needs of
the species. Adequate regulations are also not in place to ameliorate
the threats resulting from predation, genetic issues, or invasive
weeds. Due to the impacts resulting from the issues described above and
the current small population sizes and habitat areas, impacts from
other stressors such as fences, recreation, grazing, powerlines, and
drought/weather are likely acting cumulatively to further decrease the
likelihood of at least the six small populations, and potentially all
seven, persisting into the future. We believe the ability of all
remaining populations and habitat areas to retain the attributes
required for long-term sustainability of this landscape-scale species
are highly diminished indicating that the magnitude of threats is high.
Under our LPN Guidance, the second criterion we consider in
assigning a listing priority is the immediacy of threats. This
criterion is intended to ensure that the species facing actual,
identifiable threats are given priority over those for which threats
are only potential or that are intrinsically vulnerable but are not
known to be presently facing such threats. We consider the threats
imminent because we have factual information that the threats are
identifiable and that the species is currently facing them in many
portions of its range. These actual, identifiable threats are covered
in great detail in Factors A, C, D, and E of this finding and currently
include habitat degradation and fragmentation from exurban development
and roads, inadequate regulatory mechanisms, genetic issues, predation,
invasive plants, and drought/weather. In addition to their current
existence, we expect these threats to continue and likely intensify in
the foreseeable future.
The third criterion in our LPN guidance is intended to devote
resources to those species representing highly distinctive or isolated
gene pools as reflected by taxonomy. The Gunnison sage-grouse is a
valid taxon at the species level, and therefore receives a higher
priority than subspecies or DPSs, but a lower priority than species in
a monotypic genus.
We will continue to monitor the threats to the Gunnison sage-
grouse, and the species' status on an annual basis, and should the
magnitude or the imminence of the threats change, we will re-visit our
assessment of LPN.
Currently, work on a proposed listing determination for the
Gunnison sage-grouse is precluded by work on higher priority listing
actions with absolute statutory, court-ordered, or court-approved
deadlines and final listing determinations for those species that were
proposed for listing with funds from FY 2009. Additionally, remaining
listing funding from FY 2010 has been directed to work on listing
determinations for species at significantly greater risk of extinction
than the Gunnison sage-grouse faces. Because of the large number of
high-priority species, we further ranked the candidate species with an
LPN of 2. The resulting ``Top 40'' list of candidate species have the
highest priority to receive funding to work on a proposed
[[Page 59854]]
listing determination (see the Preclusion and Expeditious Progress
section below). This work includes all the actions listed in the tables
below under expeditious progress.
Preclusion and Expeditious Progress
Preclusion is a function of the listing priority of a species in
relation to the resources that are available and competing demands for
those resources. Thus, in any given fiscal year (FY), multiple factors
dictate whether it will be possible to undertake work on a proposed
listing regulation or whether promulgation of such a proposal is
warranted but precluded by higher-priority listing actions.
The resources available for listing actions are determined through
the annual Congressional appropriations process. The appropriation for
the Service Listing Program is available to support work involving the
following listing actions: Proposed and final listing rules; 90-day and
12-month findings on petitions to add species to the Lists of
Endangered and Threatened Wildlife and Plants (Lists) or to change the
status of a species from threatened to endangered; annual
determinations on prior ``warranted but precluded'' petition findings
as required under section 4(b)(3)(C)(i) of the Act; critical habitat
petition findings; proposed and final rules designating critical
habitat; and litigation-related, administrative, and program-management
functions (including preparing and allocating budgets, responding to
Congressional and public inquiries, and conducting public outreach
regarding listing and critical habitat). The work involved in preparing
various listing documents can be extensive and may include, but is not
limited to: Gathering and assessing the best scientific and commercial
data available and conducting analyses used as the basis for our
decisions; writing and publishing documents; and obtaining, reviewing,
and evaluating public comments and peer review comments on proposed
rules and incorporating relevant information into final rules. The
number of listing actions that we can undertake in a given year also is
influenced by the complexity of those listing actions; that is, more
complex actions generally are more costly. The median cost for
preparing and publishing a 90-day finding is $39, 276; for a 12-month
finding, $100,690; for a proposed rule with critical habitat, $345,000;
and for a final listing rule with critical habitat, the median cost is
$305,000.
We cannot spend more than is appropriated for the Listing Program
without violating the Anti-Deficiency Act (see 31 U.S.C.
1341(a)(1)(A)). In addition, in FY 1998 and for each fiscal year since
then, Congress has placed a statutory cap on funds which may be
expended for the Listing Program, equal to the amount expressly
appropriated for that purpose in that fiscal year. This cap was
designed to prevent funds appropriated for other functions under the
Act (for example, recovery funds for removing species from the Lists),
or for other Service programs, from being used for Listing Program
actions (see House Report 105-163, 105\th\ Congress, 1st Session, July
1, 1997).
Since FY 2002, the Service's budget has included a critical habitat
subcap to ensure that some funds are available for other work in the
Listing Program (``The critical habitat designation subcap will ensure
that some funding is available to address other listing activities''
(House Report No. 107 - 103, 107\th\ Congress, 1st Session, June 19,
2001)). In FY 2002 and each year until FY 2006, the Service has had to
use virtually the entire critical habitat subcap to address court-
mandated designations of critical habitat, and consequently none of the
critical habitat subcap funds have been available for other listing
activities. In FY 2007, we were able to use some of the critical
habitat subcap funds to fund proposed listing determinations for high-
priority candidate species. In FY 2009, while we were unable to use any
of the critical habitat subcap funds to fund proposed listing
determinations, we did use some of this money to fund the critical
habitat portion of some proposed listing determinations so that the
proposed listing determination and proposed critical habitat
designation could be combined into one rule, thereby being more
efficient in our work. In FY 2010, we are using some of the critical
habitat subcap funds to fund actions with statutory deadlines.
Thus, through the listing cap, the critical habitat subcap, and the
amount of funds needed to address court-mandated critical habitat
designations, Congress and the courts have in effect determined the
amount of money available for other listing activities. Therefore, the
funds in the listing cap, other than those needed to address court-
mandated critical habitat for already listed species, set the limits on
our determinations of preclusion and expeditious progress.
Congress also recognized that the availability of resources was the
key element in deciding, when making a 12-month petition finding,
whether we would prepare and issue a listing proposal or instead make a
``warranted but precluded'' finding for a given species. The Conference
Report accompanying Public Law 97-304, which established the current
statutory deadlines and the warranted-but-precluded finding, states (in
a discussion on 90-day petition findings that by its own terms also
covers 12-month findings) that the deadlines were ``not intended to
allow the Secretary to delay commencing the rulemaking process for any
reason other than that the existence of pending or imminent proposals
to list species subject to a greater degree of threat would make
allocation of resources to such a petition [that is, for a lower-
ranking species] unwise.''
In FY 2010, expeditious progress is that amount of work that can be
achieved with $10,471,000, which is the amount of money that Congress
appropriated for the Listing Program (that is, the portion of the
Listing Program funding not related to critical habitat designations
for species that are already listed). However these funds are not
enough to fully fund all our court-ordered and statutory listing
actions in FY 2010, so we are using $1,114,417 of our critical habitat
subcap funds in order to work on all of our required petition findings
and listing determinations. This brings the total amount of funds we
have for listing actions in FY 2010 to $11,585,417. Our process is to
make our determinations of preclusion on a nationwide basis to ensure
that the species most in need of listing will be addressed first and
also because we allocate our listing budget on a nationwide basis. The
$11,585,417 is being used to fund work in the following categories:
compliance with court orders and court-approved settlement agreements
requiring that petition findings or listing determinations be completed
by a specific date; section 4 (of the Act) listing actions with
absolute statutory deadlines; essential litigation-related,
administrative, and listing program-management functions; and high-
priority listing actions for some of our candidate species. In 2009,
the responsibility for listing foreign species under the Act was
transferred from the Division of Scientific Authority, International
Affairs Program, to the Endangered Species Program. Starting in FY
2010, a portion of our funding is being used to work on the actions
described above as they apply to listing actions for foreign species.
This has the potential to further reduce funding available for domestic
listing actions. Although there are currently no foreign species issues
included in our high-priority listing actions at this time, many
actions have statutory or court-
[[Page 59855]]
approved settlement deadlines, thus increasing their priority. The
allocations for each specific listing action are identified in the
Service's FY 2010 Allocation Table (part of our administrative record).
Based on our September 21, 1983, guidance for assigning an LPN for
each candidate species (48 FR 43098), we have a significant number of
species with a LPN of 2. Using this guidance, we assign each candidate
an LPN of 1 to 12, depending on the magnitude of threats (high vs.
moderate to low), immediacy of threats (imminent or nonimminent), and
taxonomic status of the species (in order of priority: monotypic genus
(a species that is the sole member of a genus); species; or part of a
species (subspecies, distinct population segment, or significant
portion of the range)). The lower the listing priority number, the
higher the listing priority (that is, a species with an LPN of 1 would
have the highest listing priority). Because of the large number of
high-priority species, we have further ranked the candidate species
with an LPN of 2 by using the following extinction-risk type criteria:
International Union for the Conservation of Nature and Natural
Resources (IUCN) Red list status/rank, Heritage rank (provided by
NatureServe), Heritage threat rank (provided by NatureServe), and
species currently with fewer than 50 individuals, or 4 or fewer
populations. Those species with the highest IUCN rank (critically
endangered), the highest Heritage rank (G1), the highest Heritage
threat rank (substantial, imminent threats), and currently with fewer
than 50 individuals, or fewer than 4 populations, originally comprised
a group of approximately 40 candidate species (``Top 40''). These 40
candidate species have had the highest priority to receive funding to
work on a proposed listing determination. As we work on proposed and
final listing rules for those 40 candidates, we apply the ranking
criteria to the next group of candidates with an LPN of 2 and 3 to
determine the next set of highest priority candidate species.
To be more efficient in our listing process, as we work on proposed
rules for the highest priority species in the next several years, we
are preparing multi-species proposals when appropriate, and these may
include species with lower priority if they overlap geographically or
have the same threats as a species with an LPN of 2. In addition,
available staff resources are also a factor in determining high-
priority species provided with funding. Finally, proposed rules for
reclassification of threatened species to endangered are lower
priority, since as listed species, they are already afforded the
protection of the Act and implementing regulations.
We assigned the Gunnison sage-grouse an LPN of 2, based on our
finding that the species faces immediate and high magnitude threats
from the present or threatened destruction, modification, or
curtailment of its habitat; predation; the inadequacy of existing
regulatory mechanisms; and other natural or man-made factors affecting
its continued existence. One or more of the threats discussed above
occurs in each known population. These threats are ongoing and, in some
cases, considered irreversible. Under our 1983 Guidelines, a
``species'' facing imminent high-magnitude threats is assigned an LPN
of 1, 2, or 3 depending on its taxonomic status. Because the Gunnison
sage-grouse is a species, we assigned it an LPN of 2 (the highest
category available for a species). Therefore, work on a proposed
listing determination for the Gunnison sage-grouse is precluded by work
on higher priority candidate species; listing actions with absolute
statutory, court ordered, or court-approved deadlines; and final
listing determinations for those species that were proposed for listing
with funds from previous fiscal years. This work includes all the
actions listed in the tables below under expeditious progress.
As explained above, a determination that listing is warranted but
precluded must also demonstrate that expeditious progress is being made
to add or remove qualified species to and from the Lists of Endangered
and Threatened Wildlife and Plants. (Although we do not discuss it in
detail here, we are also making expeditious progress in removing
species from the Lists under the Recovery program, which is funded by a
separate line item in the budget of the Endangered Species Program. As
explained above in our description of the statutory cap on Listing
Program funds, the Recovery Program funds and actions supported by them
cannot be considered in determining expeditious progress made in the
Listing Program.) As with our ``precluded'' finding, expeditious
progress in adding qualified species to the Lists is a function of the
resources available and the competing demands for those funds. Given
that limitation, we find that we are making progress in FY 2010 in the
Listing Program. This progress included preparing and publishing the
following determinations:
FY 2010 Completed Listing Actions
----------------------------------------------------------------------------------------------------------------
Publication Date Title Actions FR Pages
----------------------------------------------------------------------------------------------------------------
10/08/2009 Listing Lepidium Final Listing 74 FR 52013-52064
papilliferum Threatened
(Slickspot
Peppergrass) as a
Threatened Species
Throughout Its Range
----------------------------------------------------------------------------------------------------------------
10/27/2009 90-day Finding on a Notice of 90-day 74 FR 55177-55180
Petition To List the Petition Finding, Not
American Dipper in the substantial
Black Hills of South
Dakota as
Threatened or
Endangered.
----------------------------------------------------------------------------------------------------------------
10/28/2009 Status Review of Arctic Notice of Intent to 74 FR 55524-55525
Grayling (Thymallus Conduct Status Review
arcticus) in the Upper
Missouri River System
----------------------------------------------------------------------------------------------------------------
11/03/2009 Listing the British Proposed Listing 74 FR 56757-56770
Columbia Distinct Threatened
Population Segment of
the Queen Charlotte
Goshawk Under the
Endangered Species Act:
Proposed rule..
----------------------------------------------------------------------------------------------------------------
[[Page 59856]]
11/03/2009 Listing the Salmon- Proposed Listing 74 FR 56770-56791
Crested Cockatoo as Threatened
Threatened Throughout
Its Range with Special
Rule
----------------------------------------------------------------------------------------------------------------
11/23/2009 Status Review of Notice of Intent to 74 FR 61100-61102
Gunnison sage-grouse Conduct Status Review
(Centrocercus minimus)
----------------------------------------------------------------------------------------------------------------
12/03/2009 12-Month Finding on a Notice of 12-month 74 FR 63343-63366
Petition to List the petition finding, Not
Black-tailed Prairie warranted
Dog as Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
12/03/2009 90-Day Finding on a Notice of 90-day 74 FR 63337-63343
Petition to List Petition Finding,
Sprague's Pipit as Substantial
Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
12/15/2009 90-Day Finding on Notice of 90-day 74 FR 66260-66271
Petitions To List Nine Petition Finding,
Species of Mussels Substantial
From Texas as
Threatened or
Endangered With
Critical Habitat.
----------------------------------------------------------------------------------------------------------------
12/16/2009 Partial 90-Day Finding Notice of 90-day 74 FR 66865-66905
on a Petition to List Petition Finding, Not
475 Species in the substantial and
Southwestern United Subtantial
States as.
Threatened or
Endangered With.
Critical Habitat.......
----------------------------------------------------------------------------------------------------------------
12/17/2009 12-month Finding on a Notice of 12-month 74 FR 66937-66950
Petition To Change the petition finding,
Final Listing of the Warranted but
Distinct Population precluded
Segment of the Canada
Lynx To Include New.
Mexico.................
----------------------------------------------------------------------------------------------------------------
1/05/2010 Listing Foreign Bird Proposed Listing 75 FR 605-649
Species in Peru and Endangered
Bolivia as Endangered
Throughout Their Range
----------------------------------------------------------------------------------------------------------------
1/05/2010 Listing Six Foreign Proposed Listing 75 FR 286-310
Birds as Endangered
Endangered Throughout
Their Range.
----------------------------------------------------------------------------------------------------------------
1/05/2010 Withdrawal of Proposed Proposed rule, 75 FR 310-316
Rule to List Cook's withdrawal
Petrel
----------------------------------------------------------------------------------------------------------------
1/05/2010 Final Rule to List the Final Listing 75 FR 235-250
Galapagos Threatened
Petrel and Heinroth's
Shearwater as
Threatened Throughout
Their Ranges.
----------------------------------------------------------------------------------------------------------------
1/20/2010 Initiation of Status Notice of Intent to 75 FR 3190-3191
Review for Agave Conduct Status Review
eggersiana and Solanum
conocarpum
----------------------------------------------------------------------------------------------------------------
2/09/2010 12-month Finding on a Notice of 12-month 75 FR 6437-6471
Petition to List the petition finding, Not
American Pika as warranted
Threatened or
Endangered.
----------------------------------------------------------------------------------------------------------------
2/25/2010 12-Month Finding on a Notice of 12-month 75 FR 8601-8621
Petition To List the petition finding, Not
Sonoran Desert warranted
Population of the Bald
Eagle as a Threatened
or Endangered Distinct
Population Segment
----------------------------------------------------------------------------------------------------------------
2/25/2010 Withdrawal of Proposed Withdrawal of Proposed 75 FR 8621-8644
Rule To List the Rule to List
Southwestern
Washington/
Columbia River Distinct
Population Segment of
Coastal Cutthroat
Trout (Oncorhynchus
clarki clarki) as
Threatened.
----------------------------------------------------------------------------------------------------------------
3/18/2010 90-Day Finding on a Notice of 90-day 75 FR 13068-13071
Petition to List the Petition Finding,
Berry Cave salamander Substantial
as
Endangered.............
----------------------------------------------------------------------------------------------------------------
[[Page 59857]]
3/23/2010 90-Day Finding on a Notice of 90-day 75 FR 13717-13720
Petition to List the Petition Finding, Not
Southern Hickorynut substantial
Mussel (Obovaria
jacksoniana) as
Endangered or
Threatened.
----------------------------------------------------------------------------------------------------------------
3/23/2010 90-Day Finding on a Notice of 90-day 75 FR 13720-13726
Petition to List the Petition Finding,
Striped Newt as Substantial
Threatened
----------------------------------------------------------------------------------------------------------------
3/23/2010 12-Month Findings for Notice of 12-month 75 FR 13910-14014
Petitions to List the petition finding,
Greater Sage-Grouse Warranted but
(Centrocercus precluded
urophasianus) as
Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
3/31/2010 12-Month Finding on a Notice of 12-month 75 FR 16050-16065
Petition to List the petition finding,
Tucson Shovel-Nosed Warranted but
Snake (Chionactis precluded
occipitalis klauberi)
as Threatened or
Endangered with
Critical Habitat
----------------------------------------------------------------------------------------------------------------
4/5/2010 90-Day Finding on a Notice of 90-day 75 FR 17062-17070
Petition To List Petition Finding,
Thorne's Hairstreak Substantial
Butterfly as or
Endangered
----------------------------------------------------------------------------------------------------------------
4/6/2010 12-month Finding on a Notice of 12-month 75 FR 17352-17363
Petition To List the petition finding, Not
Mountain Whitefish in warranted
the Big Lost River,
Idaho, as
Endangered or
Threatened.
----------------------------------------------------------------------------------------------------------------
4/6/2010 90-Day Finding on a Notice of 90-day 75 FR 17363-17367
Petition to List a Petition Finding, Not
Stonefly (Isoperla substantial
jewetti) and a Mayfly
(Fallceon eatoni) as
Threatened or
Endangered with.
Critical Habitat.......
----------------------------------------------------------------------------------------------------------------
4/7/2010 12-Month Finding on a Notice of 12-month 75 FR 17667-17680
Petition to Reclassify petition finding,
the Delta Smelt From Warranted but
Threatened to precluded
Endangered Throughout
Its Range
----------------------------------------------------------------------------------------------------------------
4/13/2010 Determination of Final ListingEndangered 75 FR 18959-19165
Endangered Status for
48 Species on Kauai
and
Designation of Critical
Habitat.
----------------------------------------------------------------------------------------------------------------
4/15/2010 Initiation of Status Notice of Initiation of 75 FR 19591-19592
Review of the North Status Review
American Wolverine in
the Contiguous United
States
----------------------------------------------------------------------------------------------------------------
4/15/2010 12-Month Finding on a Notice of 12-month 75 FR 19592-19607
Petition to List the petition finding, Not
Wyoming Pocket Gopher warranted
as Endangered or
Threatened with
Critical Habitat
----------------------------------------------------------------------------------------------------------------
4/16/2010 90-Day Finding on a Notice of 90-day 75 FR 19925-19935
Petition to List a Petition Finding,
Distinct Population Substantial
Segment of the Fisher
in Its United States
Northern Rocky
Mountain Range as
Endangered or
Threatened with.
Critical Habitat.......
----------------------------------------------------------------------------------------------------------------
4/20/2010 Initiation of Status Notice of Initiation of 75 FR 20547-20548
Review for Status Review
Sacramento splittail
(Pogonichthys
macrolepidotus).
----------------------------------------------------------------------------------------------------------------
4/26/2010 90-Day Finding on a Notice of 90-day 75 FR 21568-21571
Petition to List the Petition Finding,
Harlequin Butterfly as Substantial
Endangered.............
----------------------------------------------------------------------------------------------------------------
4/27/2010 12-Month Finding on a Notice of 12-month 75 FR 22012-22025
Petition to List petition finding, Not
Susan's Purse-making warranted
Caddisfly
(Ochrotrichia susanae)
as
Threatened or
Endangered.
----------------------------------------------------------------------------------------------------------------
[[Page 59858]]
4/27/2010 90-day Finding on a Notice of 90-day 75 FR 22063-22070
Petition to List the Petition Finding,
Mohave Ground Squirrel Substantial
as
Endangered with
Critical Habitat.
----------------------------------------------------------------------------------------------------------------
5/4/2010 90-Day Finding on a Notice of 90-day 75 FR 23654-23663
Petition to List Petition Finding,
Hermes Copper Substantial
Butterfly as
Threatened or
Endangered.
----------------------------------------------------------------------------------------------------------------
6/1/2010 90-Day Finding on a Notice of 90-day 75 FR 30313-30318
Petition To List Petition Finding,
Castanea pumila var. Substantial
ozarkensis
----------------------------------------------------------------------------------------------------------------
6/1/2010 12-month Finding on a Notice of 12-month 75 FR 30338-30363
Petition to List the petition finding, Not
White-tailed Prairie warranted
Dog as Endangered or
Threatened
----------------------------------------------------------------------------------------------------------------
6/9/2010 90-Day Finding on a Notice of 90-day 75 FR 32728-32734
Petition To List van Petition Finding,
Rossem's Gull-billed Substantial
Tern as Endangered
orThreatened.
----------------------------------------------------------------------------------------------------------------
6/16/2010 90-Day Finding on Five Notice of 90-day 75 FR 34077-34088
Petitions to List Petition Finding,
Seven Species of Substantial
Hawaiian Yellow-faced
Bees as Endangered
----------------------------------------------------------------------------------------------------------------
6/22/2010 12-Month Finding on a Notice of 12-month 75 FR 35398-35424
Petition to List the petition finding,
Least Chub as Warranted but
Threatened or precluded
Endangered
----------------------------------------------------------------------------------------------------------------
6/23/2010 90-Day Finding on a Notice of 90-day 75 FR 35746-35751
Petition to List the Petition Finding,
Honduran Emerald Substantial
Hummingbird as
Endangered.
----------------------------------------------------------------------------------------------------------------
6/23/2010 Listing Ipomopsis Proposed Listing 75 FR 35721-35746
polyantha (Pagosa Endangered Proposed
Skyrocket) as Listing Threatened
Endangered Throughout
Its Range, and Listing
Penstemon debilis
(Parachute
Beardtongue) and
Phacelia submutica
(DeBeque Phacelia) as
Threatened Throughout
Their Range
----------------------------------------------------------------------------------------------------------------
6/24/2010 Listing the Flying Final Listing 75 FR 35990-36012
Earwig Hawaiian Endangered
Damselfly and Pacific
Hawaiian Damselfly As
Endangered
Throughout Their Ranges
----------------------------------------------------------------------------------------------------------------
6/24/2010 Listing the Cumberland Proposed Listing 75 FR 36035-36057
Darter, Rush Darter, Endangered
Yellowcheek Darter,
Chucky Madtom, and
Laurel Dace as
Endangered Throughout
Their Ranges.
----------------------------------------------------------------------------------------------------------------
6/29/2010 Listing the Mountain Reinstatement of 75 FR 37353-37358
Plover as Threatened Proposed Listing
Threatened
----------------------------------------------------------------------------------------------------------------
7/20/2010 90-Day Finding on a Notice of 90-day 75 FR 42033-42040
Petition to List Pinus Petition Finding,
albicaulis (Whitebark Substantial
Pine) as Endangered or
Threatened with
Critical Habitat
----------------------------------------------------------------------------------------------------------------
7/20/2010 12-Month Finding on a Notice of 12-month 75 FR 42040-42054
Petition to List the petition finding, Not
Amargosa Toad as warranted
Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
7/20/2010 90-Day Finding on a Notice of 90-day 75 FR 42059-42066
Petition to List the Petition Finding,
Giant Palouse Substantial
Earthworm (Driloleirus
americanus) as
Threatened or
Endangered.
----------------------------------------------------------------------------------------------------------------
7/27/2010 Determination on Final Listing 75 FR 43844-43853
Listing the Black- Endangered
Breasted Puffleg as
Endangered Throughout
its Range; Final Rule
----------------------------------------------------------------------------------------------------------------
[[Page 59859]]
7/27/2010 Final Rule to List the Final Listing 75 FR 43853-43864
Medium Tree-Finch Endangered
(Camarhynchus pauper)
as Endangered
Throughout Its Range
----------------------------------------------------------------------------------------------------------------
8/3/2010 Determination of Final ListingThreatened 75 FR 45497- 45527
Threatened Status for
Five Penguin Species
----------------------------------------------------------------------------------------------------------------
8/4/2010 90-Day Finding on a Notice of 90-day 75 FR 46894- 46898
Petition To List the Petition Finding,
Mexican Gray Wolf as Substantial
an
Endangered Subspecies
With Critical Habitat.
----------------------------------------------------------------------------------------------------------------
8/10/2010 90-Day Finding on a Notice of 90-day 75 FR 48294-48298
Petition to List Petition Finding,
Arctostaphylos Substantial
franciscana as
Endangered with
Critical Habitat.
----------------------------------------------------------------------------------------------------------------
8/17/2010 Listing Three Foreign Final Listing 75 FR 50813-50842
Bird Species from Endangered
Latin America and the
Caribbean as Endangered
Throughout Their Range.
----------------------------------------------------------------------------------------------------------------
8/17/2010 90-Day Finding on a Notice of 90-day 75 FR 50739-50742
Petition to List Brian Petition Finding, Not
Head Mountainsnail as substantial
Endangered or
Threatened with.
Critical Habitat.......
----------------------------------------------------------------------------------------------------------------
8/24/2010 90-Day Finding on a Notice of 90-day 75 FR 51969-51974
Petition to List the Petition Finding,
Oklahoma Grass Pink Substantial
Orchid as Endangered
or Threatened
----------------------------------------------------------------------------------------------------------------
9/1/2010 12-Month Finding on a Notice of 12-month 75 FR 53615-53629
Petition to List the petition finding, Not
White-Sided Jackrabbit warranted
as Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
9/8/2010 Proposed Rule To List Proposed Listing 75 FR 54561-54579
the Ozark Hellbender Endangered
Salamander as
Endangered.............
----------------------------------------------------------------------------------------------------------------
9/8/2010 Revised 12-Month Notice of 12-month 75 FR 54707-54753
Finding to List the petition finding,
Upper Missouri River Warranted but
Distinct precluded
Population Segment of
Arctic Grayling as
Endangered or.
Threatened.............
----------------------------------------------------------------------------------------------------------------
9/9/2010 12-Month Finding on a Notice of 12-month 75 FR 54822-54845
Petition to List the petition finding,
Jemez Mountains Warranted but
Salamander (Plethodon precluded
neomexicanus) as
Endangered or
Threatened with.
Critical Habitat.......
----------------------------------------------------------------------------------------------------------------
Our expeditious progress also includes work on listing actions that
we funded in FY 2010 but have not yet been completed to date. These
actions are listed below. Actions in the top section of the table are
being conducted under a deadline set by a court. Actions in the middle
section of the table are being conducted to meet statutory timelines,
that is, timelines required under the Act. Actions in the bottom
section of the table are high-priority listing actions. These actions
include work primarily on species with an LPN of 2, and selection of
these species is partially based on available staff resources, and when
appropriate, include species with a lower priority if they overlap
geographically or have the same threats as the species with the high
priority. Including these species together in the same proposed rule
results in considerable savings in time and funding, as compared to
preparing separate proposed rules for each of them in the future.
Actions funded in FY 2010 but not yet completed
------------------------------------------------------------------------
Species Action
------------------------------------------------------------------------
Actions Subject to Court Order/Settlement Agreement
------------------------------------------------------------------------
6 Birds from Eurasia Final listing determination
------------------------------------------------------------------------
[[Page 59860]]
African penguin Final listing determination
------------------------------------------------------------------------
Flat-tailed horned lizard Final listing determination
------------------------------------------------------------------------
Mountain plover\4\ Final listing determination
------------------------------------------------------------------------
6 Birds from Peru Proposed listing
determination
------------------------------------------------------------------------
Sacramento splittail 12-month petition finding
------------------------------------------------------------------------
Pacific walrus 12-month petition finding
------------------------------------------------------------------------
Gunnison sage-grouse 12-month petition finding
------------------------------------------------------------------------
Wolverine 12-month petition finding
------------------------------------------------------------------------
Agave eggergsiana 12-month petition finding
------------------------------------------------------------------------
Solanum conocarpum 12-month petition finding
------------------------------------------------------------------------
Sprague's pipit 12-month petition finding
------------------------------------------------------------------------
Desert tortoise - Sonoran population 12-month petition finding
------------------------------------------------------------------------
Pygmy rabbit (rangewide)\1\ 12-month petition finding
------------------------------------------------------------------------
Thorne's Hairstreak butterfly\3\ 12-month petition finding
------------------------------------------------------------------------
Hermes copper butterfly\3\ 12-month petition finding
------------------------------------------------------------------------
Actions with Statutory Deadlines
------------------------------------------------------------------------
Casey's june beetle Final listing determination
------------------------------------------------------------------------
Georgia pigtoe, interrupted rocksnail, Final listing determination
and rough hornsnail
------------------------------------------------------------------------
7 Bird species from Brazil Final listing determination
------------------------------------------------------------------------
Southern rockhopper penguin - Campbell Final listing determination
Plateau population
------------------------------------------------------------------------
5 Bird species from Colombia and Ecuador Final listing determination
------------------------------------------------------------------------
Queen Charlotte goshawk Final listing determination
------------------------------------------------------------------------
5 species southeast fish (Cumberland Final listing determination
darter, rush darter, yellowcheek darter,
chucky madtom, and laurel dace)
------------------------------------------------------------------------
Salmon crested cockatoo Proposed listing
determination
------------------------------------------------------------------------
CA golden trout 12-month petition finding
------------------------------------------------------------------------
Black-footed albatross 12-month petition finding
------------------------------------------------------------------------
Mount Charleston blue butterfly 12-month petition finding
------------------------------------------------------------------------
Mojave fringe-toed lizard\1\ 12-month petition finding
------------------------------------------------------------------------
Kokanee - Lake Sammamish population\1\ 12-month petition finding
------------------------------------------------------------------------
Cactus ferruginous pygmy-owl\1\ 12-month petition finding
------------------------------------------------------------------------
Northern leopard frog 12-month petition finding
------------------------------------------------------------------------
Tehachapi slender salamander 12-month petition finding
------------------------------------------------------------------------
Coqui Llanero 12-month petition finding
------------------------------------------------------------------------
Dusky tree vole 12-month petition finding
------------------------------------------------------------------------
3 MT invertebrates (mist forestfly(Lednia 12-month petition finding
tumana), Oreohelix sp.3, Oreohelix sp.
31) from 206 species petition
------------------------------------------------------------------------
[[Page 59861]]
5 UT plants (Astragalus hamiltonii, 12-month petition finding
Eriogonum soredium, Lepidium ostleri,
Penstemon flowersii, Trifolium
friscanum) from 206 species petition
------------------------------------------------------------------------
2 CO plants (Astragalus microcymbus, 12-month petition finding
Astragalus schmolliae) from 206 species
petition
------------------------------------------------------------------------
5 WY plants (Abronia ammophila, Agrostis 12-month petition finding
rossiae, Astragalus proimanthus,
Boechere (Arabis) pusilla, Penstemon
gibbensii) from 206 species petition
------------------------------------------------------------------------
Leatherside chub (from 206 species 12-month petition finding
petition)
------------------------------------------------------------------------
Frigid ambersnail (from 206 species 12-month petition finding
petition)
------------------------------------------------------------------------
Gopher tortoise - eastern population 12-month petition finding
------------------------------------------------------------------------
Wrights marsh thistle 12-month petition finding
------------------------------------------------------------------------
67 of 475 southwest species 12-month petition finding
------------------------------------------------------------------------
Grand Canyon scorpion (from 475 species 12-month petition finding
petition)
------------------------------------------------------------------------
Anacroneuria wipukupa (a stonefly from 12-month petition finding
475 species petition)
------------------------------------------------------------------------
Rattlesnake-master borer moth (from 475 12-month petition finding
species petition)
------------------------------------------------------------------------
3 Texas moths (Ursia furtiva, 12-month petition finding
Sphingicampa blanchardi, Agapema
galbina) (from 475 species petition)
------------------------------------------------------------------------
2 Texas shiners (Cyprinella sp., 12-month petition finding
Cyprinella lepida) (from 475 species
petition)
------------------------------------------------------------------------
3 South Arizona plants (Erigeron 12-month petition finding
piscaticus, Astragalus hypoxylus,
Amoreuxia gonzalezii) (from 475 species
petition)
------------------------------------------------------------------------
5 Central Texas mussel species (3 from 12-month petition finding
474 species petition)
------------------------------------------------------------------------
14 parrots (foreign species) 12-month petition finding
------------------------------------------------------------------------
Berry Cave salamander\1\ 12-month petition finding
------------------------------------------------------------------------
Striped Newt\1\ 12-month petition finding
------------------------------------------------------------------------
Fisher - Northern Rocky Mountain Range\1\ 12-month petition finding
------------------------------------------------------------------------
Mohave Ground Squirrel\1\ 12-month petition finding
------------------------------------------------------------------------
Puerto Rico Harlequin Butterfly 12-month petition finding
------------------------------------------------------------------------
Western gull-billed tern 12-month petition finding
------------------------------------------------------------------------
Ozark chinquapin (Castanea pumila var. 12-month petition finding
ozarkensis)
------------------------------------------------------------------------
HI yellow-faced bees 12-month petition finding
------------------------------------------------------------------------
Giant Palouse earthworm 12-month petition finding
------------------------------------------------------------------------
Whitebark pine 12-month petition finding
------------------------------------------------------------------------
OK grass pink (Calopogon oklahomensis)\1\ 12-month petition finding
------------------------------------------------------------------------
Southeastern pop snowy plover & wintering 90-day petition finding
pop. of piping plover\1\
------------------------------------------------------------------------
Eagle Lake trout\1\ 90-day petition finding
------------------------------------------------------------------------
Smooth-billed ani\1\ 90-day petition finding
------------------------------------------------------------------------
Bay Springs salamander\1\ 90-day petition finding
------------------------------------------------------------------------
32 species of snails and slugs\1\ 90-day petition finding
------------------------------------------------------------------------
42 snail species (Nevada & Utah) 90-day petition finding
------------------------------------------------------------------------
[[Page 59862]]
Red knot roselaari subspecies 90-day petition finding
------------------------------------------------------------------------
Peary caribou 90-day petition finding
------------------------------------------------------------------------
Plains bison 90-day petition finding
------------------------------------------------------------------------
Spring Mountains checkerspot butterfly 90-day petition finding
------------------------------------------------------------------------
Spring pygmy sunfish 90-day petition finding
------------------------------------------------------------------------
Bay skipper 90-day petition finding
------------------------------------------------------------------------
Unsilvered fritillary 90-day petition finding
------------------------------------------------------------------------
Texas kangaroo rat 90-day petition finding
------------------------------------------------------------------------
Spot-tailed earless lizard 90-day petition finding
------------------------------------------------------------------------
Eastern small-footed bat 90-day petition finding
------------------------------------------------------------------------
Northern long-eared bat 90-day petition finding
------------------------------------------------------------------------
Prairie chub 90-day petition finding
------------------------------------------------------------------------
10 species of Great Basin butterfly 90-day petition finding
------------------------------------------------------------------------
6 sand dune (scarab) beetles 90-day petition finding
------------------------------------------------------------------------
Golden-winged warbler 90-day petition finding
------------------------------------------------------------------------
Sand-verbena moth 90-day petition finding
------------------------------------------------------------------------
404 Southeast species 90-day petition finding
------------------------------------------------------------------------
High-Priority Listing Actions\3\
------------------------------------------------------------------------
19 Oahu candidate species\2\ (16 plants, Proposed listing
3 damselflies) (15 with LPN = 2, 3 with
LPN = 3, 1 with LPN =9)
------------------------------------------------------------------------
19 Maui-Nui candidate species\2\ (16 Proposed listing
plants, 3 tree snails) (14 with LPN = 2,
2 with LPN = 3, 3 with LPN = 8)
------------------------------------------------------------------------
Dune sagebrush lizard (formerly Sand dune Proposed listing
lizard)\3\ (LPN = 2)
------------------------------------------------------------------------
2 Arizona springsnails\2\ (Pyrgulopsis Proposed listing
bernadina (LPN = 2), Pyrgulopsis
trivialis (LPN = 2))
------------------------------------------------------------------------
New Mexico springsnail\2\ (Pyrgulopsis Proposed listing
chupaderae (LPN = 2)
------------------------------------------------------------------------
2 mussels\2\ (rayed bean (LPN = 2), Proposed listing
snuffbox No LPN)
------------------------------------------------------------------------
2 mussels\2\ (sheepnose (LPN = 2), Proposed listing
spectaclecase (LPN = 4),)
------------------------------------------------------------------------
Altamaha spinymussel\2\ (LPN = 2) Proposed listing
------------------------------------------------------------------------
8 southeast mussels (southern kidneyshell Proposed listing
(LPN = 2), round ebonyshell (LPN = 2),
Alabama pearlshell (LPN = 2), southern
sandshell (LPN = 5), fuzzy pigtoe (LPN =
5), Choctaw bean (LPN = 5), narrow
pigtoe (LPN = 5), and tapered pigtoe
(LPN = 11))
------------------------------------------------------------------------
\1\ Funds for listing actions for these species were provided in
previous FYs.
\2\ Although funds for these high-priority listing actions were provided
in FY 2008 or 2009, due to the complexity of these actions and
competing priorities, these actions are still being developed.
\3\Partially funded with FY 2010 funds; also will be funded with FY 2011
funds.
We have endeavored to make our listing actions as efficient and
timely as possible, given the requirements of the relevant law and
regulations, and constraints relating to workload and personnel. We are
continually considering ways to streamline processes or achieve
economies of scale, such as by batching related actions together. Given
our limited budget for implementing section 4 of the Act, these actions
described above collectively constitute expeditious progress.
The Gunnison sage-grouse will be added to the list of candidate
species upon publication of this 12-month finding. We will continue to
monitor the status of this species as new information becomes
available. This review will determine if a change in status is
[[Page 59863]]
warranted, including the need to make prompt use of emergency listing
procedures.
We intend that any proposed listing action for the Gunnison sage-
grouse will be as accurate as possible. Therefore, we will continue to
accept additional information and comments from all concerned
governmental agencies, the scientific community, industry, or any other
interested party concerning this finding.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Western Colorado
Ecological Services Field Office (see ADDRESSES section).
Author(s)
The primary authors of this notice are the staff members of the
Western Colorado Ecological Services Field Office.
Authority
The authority for this section is section 4 of the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: September 7, 2010
Paul R. Schmidt,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2010-23430 Filed 9-27-10; 8:45 am]
BILLING CODE 4310-55-S