3.4.6. Fish and Wildlife Resources – Wildlife

The BLM has grouped the wildlife species described in this RMP and EIS according to Wyoming Statutory Wildlife Categories. This section describes existing conditions and management challenges for habitat types and statutory wildlife groups in the Planning Area. Management actions are incorporated in the alternatives and described in more detail in Chapter 2. For purposes of this discussion, the terms habitat and vegetative types are used interchangeably.

Wildlife and Habitats in the Planning Area

There is a diversity of wildlife habitats in the Planning Area, primarily because of its location between three physiographic areas - the Northern Shortgrass Prairie to the north and east, the Central Rocky Mountains to the west, and the Wyoming Basin to the south of and including the Planning Area. Also, the Bighorn Basin is a basin bounded by mountains that affect floral and faunal distribution, which also defines the diversity of habitats and species in the Bighorn Basin.

Lands in the Planning Area contain a variety of habitats that possess the biological and physical attributes important in the life-cycles of many wildlife species. The diversity of habitats and landscapes provide important areas for breeding, birthing, foraging, wintering, and migration. Wildlife and their habitats are representative of Great Basin fauna and flora. Wildlife habitat is best characterized by vegetation types, water resources, geology, and topography. Vegetation types are characterized as successional stages, commonly influenced by disturbance regimes like fire, grazing, and drought. Just as a diversity of vegetation types is important to wildlife, so are these successional stages within types. Habitats in the Planning Area include sagebrush-steppe shrublands, coniferous forests, juniper woodlands, aspen stands, mountain shrub, canyons and rim rock, badlands, grasslands, and riparian/wetland areas. See the Vegetation sections in this chapter for more information about these habitat types in the Planning Area.

Factors such as fire, forestry, ROWs, livestock grazing management, motorized vehicle use, and OHV use and other types of recreation also influence the quality of habitat, as do management actions applied throughout BLM-administered lands. It also is noteworthy that many wildlife populations spend considerable time on non-BLM-administered lands and these populations often depend to a great extent on, and are therefore affected by, management of these non-BLM-administered lands. Most wildlife species utilize vegetation on the basis of its structure (height and spacing) and the growth form (gross morphology and growth aspect) of the predominant species. Therefore, mapping vegetation zones and successional stages characterizes wildlife habitat in general terms. The BLM manages wildlife habitat in the Planning Area according to a number of HMPs and habitat management recommendations provided through the WGFD Strategic Habitat Plan (WGFD 2001); Table 3–28 lists these HMPs.

Table 3.28. Habitat Management Plans Applicable to the Planning Area

Plan

Year

Absaroka Front Habitat Management Plan (BLM 1986a)

1986

Bighorn River Habitat and Recreation Management Plan (BLM 1987)

1978 (updated 1986)

Grass Creek Resource Area Reservoir Habitat Management Plan (BLM 1983a)

1983

Washakie Resource Area Reservoir Habitat Management Plan (BLM 1994b)

1994

Grass Creek Resource Area Streams Habitat Management Plan (BLM 1984a)

1984

West Slope Habitat Management Plan (BLM 1984b)

1984

Source: BLM 2009b


Habitat in the Planning Area ranges from montane areas in the Absaroka, Owl Creek, and Big Horn Mountains to salt desert shrublands with extensive grassland and shrublands in between. See the Vegetation section in this chapter and Section 3.4.3 Riparian/Wetland Resources for descriptions of plant communities in the Bighorn Basin.

The Planning Area contains important crucial winter range for a variety of animals. Crucial winter range is often the determining factor in maintaining big game populations at objective levels.

Terrestrial vertebrate wildlife species present in the Bighorn Basin represent all major vertebrate classesreptiles, amphibians, birds, and mammals. Management emphasis is primarily placed on birds and mammals because of interest in them by the hunting and recreating public. The following paragraphs describe terrestrial wildlife species in the Planning Area. The descriptions are based on WGFD statutory wildlife categories to facilitate discussion regarding these species. The Special Status Species section in this chapter addresses species of special concern (threatened, endangered, and sensitive species).

Big Game

Big game species in the Planning Area include pronghorn, deer (mule deer and white-tailed deer), elk, moose, bighorn sheep, and mountain goat. Boundaries of the herd unit areas are established to encompass all the seasonal ranges and habitats or special life-function areas (e.g., calving and lambing areas) utilized by a more or less discreet population or herd. Because there will always be some interchange of animals between adjacent populations, and portions of populations change important use patterns over time, these boundaries are well defined, but not permanent. They do, however, represent the best available data and identify population units consistent with the most recent biological and climatic conditions. Table 3–29 provides information about the relative size and amount of BLM-administered lands in Planning Area big game herd units.

Table 3.29. Relative Size and Amount of BLM-administered LandsOccupied by Big Game Herd Units

Big Game Species

Herd Unit Name

Total Herd Unit Acreage in Wyoming

Herd Unit Acreage in the Planning Area

Herd Unit Percentage in the Planning Area

Herd Unit Acreage on BLM-Administered Lands

Herd Unit Percentage on BLM-Administered Lands

Pronghorn

Badger Basin

881,130

744,568

85

243,138

28

Big Horn

798,713

798,713

100

357,147

45

Copper Mountain

1,453,689

1,338,088

92

765,273

53

Fifteen Mile

2,018,131

1,542,251

76

1,136,662

56

Carter Mountain

1,342,867

1,158,195

86

625,575

47

Upper Powder River

530,156

9,702

2

572

0

Middle Fork

403,667

11,453

3

6,869

2

Badwater

672,853

38,791

6

1,488

0

Project

1,963,323

0

0

0

0

North Natrona

854,358

626

0

379

0

NOH

4,236,183

707

0

276

0

Total

15,155,070

5,643,094

37

3,137,379

21

Mule Deer

Paintrock

912,951

677,559

74

470,352

52

Southwest Bighorns

1,947,962

1,222,433

63

653,943

34

Basin

779,239

779,239

100

636,066

82

Greybull River

515,022

535,420

104

364,662

71

Clarks Fork

969,830

457,968

47

154,777

16

Upper Shoshone

1,257,245

264,246

21

58,304

5

Shoshone River

658,211

658,192

100

345,840

53

Owl Creek/Meeteetse

1,274,195

724,870

57

279,955

22

North Bighorn

1,646,136

306,423

19

218,032

13

Upper Powder River

889,715

21,353

2

7,431

1

North Natrona

874,208

629

0

380

0

Total

11,724,714

5,648,332

48

3,189,742

27

White-Tailed Deer

Bighorn Basin

8,136,731

5,597,882

69

3,180,846

39

Powder River

5,470,072

21,116

0

7,403

0

Central

4,805,444

626

0

378

0

NOH

22,662,357

28,707

0

1,115

0

Total

41,074,604

5,648,331

14

3,189,742

8

Elk

Medicine Lodge

972,778

694,547

71

477,061

49

Gooseberry

1,054,106

579,468

56

238,293

23

Cody

2,652,717

1,606,426

45

986,265

18

North Bighorn

1,537,195

304,776

20

217,988

14

Clark’s Fork

1,823,065

1,266,495

69

616,236

34

South Bighorn

3,246,973

832,979

26

350,636

11

Total

11,286,834

5,284,691

47

2,886,479

26

Moose

Owl Creek/Meeteetse

1,009,291

486,189

48

223,794

22

Bighorn Moose

2,660,671

840,783

32

580,400

22

Absaroka

3,218,987

624,552

19

149,615

5

NOH

38,619,454

2,348,893

6

1,514,836

4

NOH/W

1,914,614

658

0

123

0

Total

47,423,017

4,301,075

9

2,468,768

5

Bighorn Sheep

Francs Peak

1,552,105

863,928

56

291,591

19

Clark’s Fork

444,405

51,242

12

19,797

4

Devils Canyon

145,560

94,553

65

68,011

47

Trout Peak

503,218

134,074

27

42,828

9

Wapiti Ridge

442,642

61,699

14

19,225

4

NOH

45,530,772

2,893,272

6

1,878,377

4

NOH/W

1,332,861

652

0

122

0

Total

49,951,563

4,099,420

8

2,319,951

5

Mountain Goat

Beartooth

622,404

117,752

19

34,975

6

Total

622,404

117,752

19

34,975

6

Source: BLM 1990; BLM 2009a

BLM Bureau of Land Management


The Planning Area contains 2,417,631 acres of crucial winter range for big game, 1,313,731 acres of which is on BLM-administered lands (BLM 2009a) (Map 35). Winter is a crucial and stressful time for big game; therefore, crucial winter range is often the focus of management and a criterion for analyzing the impacts to big game from resource management. There are no feed grounds on BLM-administered lands in the Planning Area. The Planning Area contains all or part of 47 herd units (11 pronghorn, 11 mule deer, 4 white-tailed deer, 8 elk, 5 moose, 7 bighorn sheep, and 1 mountain goat). Appendix K shows the location of WGFD herd units. Specific information about population trends is available through the WGFD via the agency’s Job Completion Reports (http://gf.state.wy.us/wildlife/index.asp).

Pronghorn

Pronghorn are a unique animal of the western plains and are the only living species in their taxonomic family (Antilocapridae). Wyoming is the center of the pronghorn’s range. Pronghorn inhabit a wide variety of open rangeland habitat types throughout the Planning Area and forage primarily on shrubs, especially sage species.

Population projections for pronghorn generally have been below objectives for several years, except where herds have access to large areas of irrigated fields. This is partly due to adverse effects on the quality of the shrub component of their pronghorn habitat in many ranges. Habitat condition of many of the Wyoming big sagebrush communities associated with pronghorn winter ranges is declining due to poor productivity, plant recruitment, old age, and cheatgrass invasion that has out-competed native herbaceous and sagebrush species. Declines in habitat quality also have affected the reproduction and survival rates for pronghorn. Lower reproduction and lower recruitment of young into populations has inhibited the ability of herd populations to recover from declining numbers.

Deer

Both mule deer and white-tailed deer occur in the Planning Area, although mule deer are by far the more abundant species. Mule deer generally prefer habitat types in the early to mid stages of plant succession with numerous shrubs. They use the woody riparian, shrublands, juniper woodland, and aspen woodland habitat types extensively during spring, summer, and fall. These habitat types provide adequate forage areas with succulent vegetation for lactating females and adequate cover for security and fawning. During winter, mule deer move to lower elevations to avoid deep snow that covers their forage. They are often found in juniper and limber pine woodlands, big sagebrush/rabbitbrush, sagebrush steppe, and riparian habitat types. Because of seasonal dependence on woody plant communities, mule deer are generally declining in numbers due to a decline in habitat quality and quantity. Mule deer populations are generally below WGFD-objective numbers throughout the Planning Area.

White-tailed deer use woody riparian habitats (willow and cottonwood) along major creeks and rivers for both forage and cover. They are found mainly on private lands in the Planning Area. White-tailed deer are expanding into new areas, but it is not clear if the population is actually increasing or whether it is spreading into expanded habitat types. White-tailed deer have been affected by periodic disease outbreaks that have caused short-term, localized population declines, but overall have shown population increases.

Elk

Elk are distributed throughout the Planning Area, especially adjacent to and in areas of higher elevation that have forest or woodland cover. In summer, elk use aspen and conifer woodlands for security and thermal cover, ranging out into upland meadows, sagebrush/mixed grass, and mountain shrub habitat types to forage. In winter, elk move to lower elevations, foraging especially in sagebrush/mixed grass, and mountain shrub habitat types, and in windswept areas where snow is less deep. Elk depend on these habitats in designated crucial winter ranges to maintain populations at objective levels. For parturition, elk move into areas that provide particularly good hiding cover and succulent forage.

Elk numbers have been generally at or over objective for most herd units in the Bighorn Basin for the past two decades. Elk have possibly fared better because they are more generalist feeders than species like deer and pronghorn.

Moose

Moose are distributed in low densities throughout the Absaroka, Owl Creek, and Big Horn Mountains in the Planning Area, especially along the river and stream corridors adjacent to these mountains and in areas of higher elevation that have forest or woodland cover. In summer and fall, moose use willow, aspen, and mixed conifer forests for forage and security. Moose are primarily browsers and feed on woody species like willow, aspen, and some young conifer species. In winter, moose in the Big Horn Mountains seem to concentrate primarily in riparian corridors and mixed conifer habitats, while in the Absaroka Mountains they tend to move up in elevation to forage in mixed conifer and spruce/fir forest habitat types. Occasionally, severe winter snows push moose to lower elevations. Moose populations are generally below WGFD-objective numbers.

Bighorn Sheep

Bighorn sheep are present predominantly in the Absaroka Mountains, Owl Creek Mountains, and the Devil’s Canyon and Shell Canyon areas of the Big Horn Mountains. Populations in the Pryor Mountains across the border in Montana occasionally move into the Planning Area.

Bighorn sheep prefer open grassy ridges, slopes, or benches close to escape cover in the form of rocky outcrops, precipitous cliffs, or steep rocky slopes. They most commonly prefer herbaceous forage and typically use alpine meadows and mountain shrub habitat types, primarily foraging on forbs and grasses and converting to browsing on shrubs when snow depths dictate.

Bighorn sheep also are known to be susceptible to Pasteurella sp. bacteria commonly carried within the nasal cavities of domestic sheep and domestic goats. Pasteurella, when transferred, usually through nose to nose contact, causes sickness and death, and has caused the decline of numerous bighorn sheep populations.

The Wyoming Statewide Bighorn/Domestic Sheep Interactions Working Group has designated areas of Wyoming as bighorn sheep native core areas, cooperative review areas, and non-emphasis areas. The western edge of the Bighorn Basin is generally considered a core area and the eastern edge is a non‐emphasis area.

Bighorn sheep populations in the Planning Area have increased due to the establishment of native core areas in occupied bighorn sheep habitat and because of habitat augmentation and improvement through burning and livestock permit changes.

Mountain Goat

There are mountain goats on BLM-administered lands near Clarks Fork of the Yellowstone River canyon, predominantly in high, steep and rocky habitat. This habitat provides escape cover and shelter from the wind and storms coming off the Beartooth Plateau. It also is lower in elevation than predominantly spring and summer habitat that is higher on the Beartooth Plateau.

Mountain goat populations are stable in the Planning Area. There is one herd unit in the Planning Area, which has been hunted, and harvests are adjusted to maintain a stable, local population.

Management Challenges

Management challenges for big game species include poor habitat conditions, fire management, drought, increased development and urbanization, habitat fragmentation, motorized vehicle misuse, disease, hunter access, and the impacts of livestock grazing management on the frequency, quality, and composition of key forage species. The WGFD monitors disease in big game species. The BLM and the WGFD continually coordinate and evaluate actions affecting herd units and habitat conditions to determine the appropriate management direction.

Big game species that depend on woody plant communities (e.g., pronghorn, mule deer, and moose) are generally declining in numbers due to a decline in habitat quality and quantity. Species that depend on herbaceous plants (e.g., elk and bighorn sheep) generally have stable or increasing populations.

Trophy Game

The WGFD classifies cougar, black bear, grizzly bear, and gray wolves as trophy animals. Cougars are typically found in remote areas with dense cover and rocky, rugged terrain. They are found in most habitats where deer, their primary prey base, are present. Black bear are found throughout both the foothills and mountains of the Absaroka front and the Big Horn Mountains, with occasional occurrences along riparian corridors such as the Greybull, Bighorn, and Nowood rivers. They are typically associated with forested and riparian habitats in higher precipitation zones. Grizzly bear are found in the Absaroka and Beartooth mountain areas and have been observed along the western part of the Owl Creek Mountains. Section 3.4.9 Special Status Species - Wildlife addresses the grizzly bear and gray wolf.

In the Planning Area, there are management areas for cougar (throughout) and black bear (Absaroka, Owl Creek, and Big Horn Mountains). These represent areas where populations of these species are sufficient to support hunting and to warrant hunting management. Black bear populations are fairly stable and cougars appear to be expanding into a few new areas. However, due to the reclusive nature of black bears and cougars, it is difficult to estimate population. For additional information on trophy game, refer to the WGFD website, http://gf.state.wy.us/.

Furbearing Animals

Badger, beaver, bobcat, marten, mink, muskrat, skunk, and weasel are classified as furbearing animals and are found throughout the Bighorn Basin. Population figures for furbearing animals are available only on a statewide basis. Trapping seasons apply to most furbearers; badgers are taken year-round, while others are typically trapped in early winter (bobcat, muskrat, mink, and weasel). Trapping dates vary for beaver and marten.

Beaver, mink, and muskrat populations have likely declined across much of the Planning Area due to drought conditions. Water volumes have decreased in many riparian systems from a loss of water storage capability and from a lack of precipitation. The distribution of mink and muskrat populations has shrunk due to a loss of water in some riparian systems. Beaver depend on aspen, willow, and cottonwood trees to build and maintain their dams and lodges. Conifer trees have invaded many riparian areas adjacent to streams due to drying of these sites from a drop in the water table. Conifers take up available water and space, both surface and subsurface, choking out aspen, willow, and cottonwood communities.

Predatory Animals

According to Wyoming statute, predatory animals include jackrabbit, porcupine, coyote, gray wolf, red fox, raccoon, and skunk. Section 3.4.9 Special Status Species - Wildlife addresses the gray wolf. All of these species can be found in the Planning Area. From the standpoint of BLM management, most management efforts and attention focus on coyote, red fox, and skunk damage-control activities. The BLM does not conduct any habitat management activities for predatory animals.

USDA APHIS-Wildlife Services performs predatory animal damage-control activities on public lands, and performs these activities in response to requests from individuals, organizations, and agencies experiencing damage caused by wildlife. Animal damage-control activities primarily include mechanical (trapping, shooting, and denning), chemical (poison), and nonlethal methods (e.g., noise devices and aversive conditioning). Through the Animal Damage Management Board, the state of Wyoming also performs animal damage-control activities, particularly actions involving rabies and other diseases.

Management challenges for animal damage-control activities are to implement a program that responds to predation problems and remains socially acceptable and safe in accordance with applicable laws and regulations. Predator populations typically follow prey populations, particularly when the relationship is prey specific.

Small Game

Small game includes cottontail rabbits, snowshoe hare and fox, and gray and red squirrels. Cottontails, snowshoe hares, and squirrels are found throughout the Planning Area and are hunted from early to mid winter. Snowshoe hare are found in transition areas adjacent to conifer forest and are indicator species for Canada lynx habitat. Cottontail and white-tailed jackrabbits occur in many habitat types and are broadly distributed in the Bighorn Basin. Red squirrels are found in conifer and mixed forest habitats, generally at higher elevations. There are no available estimates of population size, mortality, and natality rates for these species.

Rabbit and squirrel populations are cyclic, so trends are difficult to determine, however, populations appear to be generally stable. Information regarding hunter days and harvest are available from the WGFD. Snowshoe hare are present in wetter forests, which occur in limited BLM-administered areas. This prey species is important for Canada lynx reproduction and survival.

Game Birds

Game bird management direction for the BLM is identified in the BLM Fish and Wildlife 2000: Upland Game Bird Habitat Management (BLM 1992a). All game bird species in Wyoming are managed for recreational use such as hunting and bird watching.

Upland game birds in the Planning Area include pheasant, ptarmigan, quail, chukar, gray partridge, blue grouse, ruffed grouse, greater sage-grouse, and turkeys. Section 3.4.9 Special Status Species - Wildlife discusses the greater sage-grouse. The forest-woodland edges adjacent to Bighorn and Shoshone National Forests support appreciable stands of preferred habitat that supports populations of blue and ruffed grouse. Chukar and gray partridges are found in hilly and rolling terrain along mountain foothills and to some extent in badland topography in lower elevations of the Bighorn Basin; the best chukar partridge habitat is along the west slope of the Big Horn Mountains in the canyons and foothills. Gray partridge are found in similar foothills and badlands habitat types in the Bighorn Basin. Pheasants are found primarily in habitat associated with riparian areas or corridors, and near or along agricultural fields.

Waterfowl

Ducks and geese occur in aquatic areas throughout the Bighorn Basin. A small number of species breed, winter, or remain yearlong in the state, while larger numbers pass through during spring or fall migration. The entire Bighorn Basin is within the Central Flyway (east of the continental divide). The various sources of water, natural lakes, streams, and manmade reservoirs are important resting areas for a variety of ducks, geese and shorebirds. Waterfowl species include ducks, geese, coots, snipe, and rails. Scattered aquatic resources found throughout the Bighorn Basin support various waterfowl species during nesting periods, and private agricultural lands provide important foraging habitat where grains and hay are grown. Most of these species depend on wetlands or open water that is sufficiently shallow to support rooted vegetation, and they feed on the biotic communities in such habitats.

One important waterfowl habitat is the Bighorn River, primarily because the southern reaches of this river remain open during winter. Many small ponds and reservoirs that have stable water levels have wetlands along their shores. In addition, pools in the numerous streams and their tributaries throughout the Planning Area provide important habitat. Only some of these aquatic resources are on BLM-administered public lands.

As a result of livestock grazing management practices, some riparian zones on public land adjacent to streams, small reservoirs, and ponds have been degraded. This results in the removal of nesting cover for waterfowl and shorebird species that could nest in these riparian zones. There are several large wetland areas in the Bighorn Basin with large amounts of BLM-administered public land that are protected from or have controlled livestock grazing. These include the Yellowtail Wildlife Habitat Management Area (WHMA), Bighorn River tracts, Wardell and Harrington Reservoirs, Loch Katrine, Renner Habitat Management Area, and several smaller fenced reservoirs that provide good nesting habitat for waterfowl and shorebirds.

Nongame Species

Nongame species include raptors, neotropical migrants, mammals, and reptiles and amphibians. Such species are numerous and diverse, especially given the diversity of habitats present in the Planning Area. This section addresses only a few of these species or groups. Many nongame species are on the BLM Wyoming State Director’s Sensitive Species List; Section 3.4.9 Special Status Species - Wildlife addresses those species. The hundreds of additional bird species that inhabit the Bighorn Basin for all or part of their life-cycles are important components of the ecosystem and an important focus of the large segment of recreationists who enjoy bird-watching.

Raptors

Raptor species (eagles, hawks, owls, falcons, and vultures) in the Bighorn Basin include osprey, red-tailed hawk, Swainson’s hawk, ferruginous hawk, northern harrier, goshawk, Cooper’s hawk, sharp-shinned hawk, rough-legged hawk, golden eagle, bald eagle, merlin, kestrel, peregrine falcon, American kestrel, prairie falcon, great-horned owl, long-eared owl, short-eared owl, great gray owl, and burrowing owl. Some raptors are sensitive to disturbance and occupy an ecological position at the top of the food chain; thus, they can act as biological indicators of environmental quality. Section 3.4.9 Special Status Species - Wildlife further discusses several of these species. Raptors are present in habitats throughout the Planning Area.

Most species have specific nest-site requirements, which are key factors in nest-site selection and in reproductive success. These generally include nesting strata, available prey base, and nest-site disturbance. Nests can occur in a myriad of habitats, including on steep cliffs and rock ledges, in trees, and on the ground. Raptors also use manmade structures such as barns, utility poles, and tanks for nesting. The nesting-reproductive season is considered the most critical period in the raptor life-cycle because it determines population productivity.

Many raptors concentrate their nests along a cliff and use this stratum for nesting year after year. These high-use/high-density raptor nesting sites are called raptor concentration areas. Golden eagles and prairie falcons usually build their nests on steep cliffs and rock ledges, and often, red-tailed hawks, great-horned owls, and American kestrels build on these sites.

Numerous raptors in the Planning Area typically nest in trees. Cooper’s hawks and sharp-shinned hawks usually nest in lodge pole, mixed conifer forests, or aspen woodlands. Swainson’s hawks prefer the more open plains area and usually nest in trees along drainage courses. Most nests in the Bighorn Basin, including most documented red-tailed hawk nests, are in cottonwood trees. Large cottonwood trees along major river corridors also are important nest sites for bald eagles. Northern harriers are ground nesters, but are generally associated with riparian/wetland sites and nest in marsh habitats.

At present, there is no population data for raptor populations; however, the golden eagle population and osprey sightings and nests appear to be increasing throughout the Planning Area.

Raptor habitat protection has been directed toward long-term nest-site protection and minimizing habitat disturbance around nesting sites during the critical nesting period. Raptor nesting stipulations have been applied to surface-disturbing activities such as ROWs and oil and gas leasing. Current stipulations consist of buffer zones around nests, season restrictions on human activities, and “raptor proofing” electrical transmission facilities to prevent electrocution of raptors.

Sensitivity to disturbance varies among individual pairs and species. Nesting pairs that choose to nest near an existing disturbance are probably less apt to abandon the nest than a pair disturbed by new activity.

Neotropical Migrants

This category includes shorebirds, water birds, and songbirds. A myriad of these species are found throughout the Bighorn Basin. Every plant community type in the Planning Area supports neotropical bird species. Riparian/wetland communities typically have the most diverse array of species.

There are no population estimates for most avian species; however, the USFWS has been organizing and conducting breeding bird surveys that provide some data on species occurrence and trend. In addition, the BLM has some observation and occurrence data for some species. In general, habitat-specific information related to migratory birds is incomplete or unknown and population status is undetermined. Degradation, fragmentation, and loss of native sagebrush landscapes have caused relatively large migratory bird declines in the important sagebrush habitat type across the West (Knick et al. 2003).

Sagebrush-obligate species populations have been declining, as indicated by the presence of these species on the BLM Sensitive Species List (BLM 2010a) and WGFD Species of Greatest Conservation Need List (WGFD 2005a). Juniper-obligate species have stable to upward trends due to the increase in juniper communities.

Mammals

Nongame mammals include species such as mice, rats, voles, ground squirrels, shrews, bats, and prairie dogs. These species are found in habitats throughout the Bighorn Basin. White-tailed prairie dog surveys from 2001 to 2005 in the northern portion of the Bighorn Basin found a 37-percent decrease in the number of towns (105 to 66) and a 71-percent decrease in occupied area (164 acres to 74 acres) from 1980 to 1989 surveys. The black-tailed prairie dog population increased slightly over the same time period but may be vulnerable due to its small size and isolation from the rest of the species’ range (Harrell and Marks 2009). There have been bat surveys in suitable caves, mines, and shafts in the Planning Area. There are several known maternity roosts and hibernacula identified in the Planning Area, primarily natural caves that are common in limestone karst areas along the Big Horn Mountains. There is one complex of black-tailed prairie dogs in the Planning Area, and this group of animals is isolated from other populations outside the area. Black-tailed prairie dogs and special status bat species are discussed further in Section 3.4.9 Special Status Species - Wildlife.

Reptiles and Amphibians

Nongame mammals include species such as mice, rats, voles, ground squirrels, shrews, bats, and prairie dogs. These species are found in habitats throughout the Bighorn Basin. White-tailed prairie dog surveys from 2001 to 2005 in the northern portion of the Bighorn Basin found a 37-percent decrease in the number of towns (105 to 66) and a 71-percent decrease in occupied area (164 acres to 74 acres) from 1980 to 1989 surveys. The black-tailed prairie dog population increased slightly over the same time period but may be vulnerable due to its small size and isolation from the rest of the species’ range (Harrell and Marks 2009). There have been bat surveys in suitable caves, mines, and shafts in the Planning Area. There are several known maternity roosts and hibernacula identified in the Planning Area, primarily natural caves that are common in limestone karst areas along the Big Horn Mountains. There is one complex of black-tailed prairie dogs in the Planning Area, and this group of animals is isolated from other populations outside the area. Black-tailed prairie dogs and special status bat species are discussed further in Section 3.4.9 Special Status Species - Wildlife.

It is estimated that the trend for reptiles is downward, but this is difficult to confirm because there are no population estimates for these species in the Planning Area. Due to the number of species that are on the Wyoming BLM Sensitive Species List and on the WGFD Species of Greatest Conservation Need List, and the declining condition of suitable habitat on public lands, the BLM assumes that amphibians are generally on a downward trend.

Special Status Species

Several policies and agreements guide management of special status species and their habitat in the Planning Area. In March 1990, the WGFD and the BLM signed an MOU (WGFD and BLM 1990), the purpose of which is to strengthen the agencies’ cooperative approach to managing wildlife and wildlife habitat on public land and to encourage the agencies to work together to develop, enhance, maintain, and manage wildlife resources, including planning and sharing data concerning biological resources.

The BLM Wyoming Sensitive Species Policy and List is prepared to focus species management efforts on maintaining habitats for these species (BLM 2010a). The goals of this policy include:

objectives of this policy are to (1) conserve listed species and the ecosystems on which they depend and (2) ensure that actions requiring BLM authorization or approval are consistent with the conservation needs of special status species and do not contribute to the need to list special status species under the provisions of the ESA or BLM Manual 6840. In addition, management actions for federally listed species are often derived through the consultation process (i.e., Section 7 of the ESA).

The USFWS provides regulatory oversight for all species that are listed, proposed for listing, or are candidates for listing under the ESA. The USFWS also administers designation of critical habitat for listed species and the Migratory Bird Treaty Act, which protects migratory bird species whether they are hunted (e.g., waterfowl) or not (e.g., songbirds). The USFWS oversees management of federally listed species and the designation of critical habitats in accordance with the ESA. Formal consultation is required on any action a federal agency proposes that (1) may adversely affect a federally listed species or (2) will result in jeopardy or adverse modification of critical habitats. Informal consultation is required on any action a federal agency proposes that (1) may affect – not likely to adversely affect or (2) may affect – may have beneficial effects. Special status species discussed in this section include those species listed as threatened or endangered, those that are proposed for listing, those that are candidates for listing, and those the BLM State Director has designated as sensitive.

The BLM is responsible for managing habitat; state and federal wildlife management agencies oversee the management of special status wildlife and fish species. The WGFD manages resident special status fisheries and wildlife populations and waterfowl in the Planning Area.