Endangered and Threatened Wildlife and Plants:

Federal Register: September 28, 2010 (Volume 75, Number 187)

Proposed Rules

Page 59803-59863

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr28se10-25

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Part II

Department of the Interior

Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife and Plants; Determination for the

Gunnison Sage-grouse as a Threatened or Endangered Species; Proposed

Rule

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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.

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

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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

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