Gunnison sage grouse are native to North America, and are found in southwestern Colorado and southeastern Utah. However, population distributions have been declining rapidly due to habitat destruction. Only five distinct populations remain, and the Gunnison Basin has the highest population diversity. Efforts to introduce sage grouse to New Mexico, Oregon, Montana, Wyoming, Utah, Colorado, and Idaho have been unsuccessful.
Gunnison sage grouse have a potential distribution of 46,521 sq km, but a current range of 4,787 sq km. There is a large difference between the potential and actual distribution of populations, which may be due to habitat alteration and degradation.
Biogeographic Regions: nearctic (Native )
endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (1000-5000 square km (about 400-2000 square miles)) This species occurs locally in the Gunnison Basin and southwestern Colorado, and in adjacent southeastern (San Juan County) Utah south and east of the Colorado River (AOU 2000, Beck et al. 2003, Schroeder et al. 2004, Gunnison Sage-grouse Rangewide Steering Committee 2005). The historical range is thought to have included southwestern Colorado, northwestern New Mexico, northeastern Arizona, and southeastern Utah (Schroeder et al. 2004). Gunnison Sage-grouse Rangewide Steering Committee (2005) includes a fairly detailed range map.
Schroeder et al. (2004) estimated that the current range is 4,787 square kilometers.
Historically, sage-grouse occurred in at least 15 states and 3 provinces from British Columbia east to Saskatchewan and south to New Mexico and California. Presently they are found in 11 states and 2 provinces [27,99]. Sage-grouse have been translocated in New Mexico, Oregon, Montana, Wyoming, Utah, Colorado, Idaho and British Columbia. New Mexico initiated the earliest attempts at translocations in 1933 after the species was extirpated from the state in 1912. Efforts were unsuccessful. British Columbia attempted to reintroduce sage-grouse in 1958. No sage-grouse have been reported since 1966 and are considered to have been extirpated within the province [68,99]. In addition, sage-grouse have been extirpated in most of North and South Dakota, Nebraska, Kansas, Oklahoma, central California [60,64,68,87], and Arizona .
Greater sage-grouse are distributed from north-central Oregon, southern Idaho, and southern Alberta and Saskatchewan south to eastern California and extreme western North and South Dakota. Isolated populations also occur in eastern Washington [66,87,124]. Western sage-grouse occur only in eastern Washington and Oregon. The ranges of western and eastern sage-grouse overlap in Oregon. Eastern sage-grouse occur in all states and provinces within the range of sage-grouse except Washington [1,24].
Gunnison sage-grouse occur in 7 counties in southwestern Colorado and 1 county in southeastern Utah .
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
BLM PHYSIOGRAPHIC REGIONS :
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
16 Upper Missouri Basin and Broken Lands
Occurrence in North America
Gunnison sage grouse display sexual dimorphism. Males have white breasts with two round yellow air sacs (cervical apteria) on their chest. These air sacs have scale-like feathers that males inflate (making a popping noise) during the spring to attract mates. Males have a black belly with a white V-shaped area separating their throat from their chest. They also have spiky brown and white tail feathers that can be fanned out for sexual signaling. Females are smaller and lighter than males and have a gray-brown coloration. Female have shorter tail feathers with less plumage and also lack the prominent air sacs present on males. Chicks resemble females and have a brown and white speckled appearance for camouflage. Adult sage grouse from southwestern Colorado have shorter and narrower beaks than adult sage grouse from northern Colorado. There are also morphological variations between Gunnison sage grouse and their close relative, greater sage grouse Centrocercus urophasianus. Gunnison sage grouse are smaller with longer black filoplumes on their heads. They are typically 32 to 51 cm long with a wingspan of 6 to 76 cm and a mass of 990 to 2435 g.
Range mass: 990 to 2435 g.
Range length: 32 to 51 cm.
Range wingspan: 66 to 76 cm.
Sexual Dimorphism: male larger; male more colorful; sexes shaped differently; ornamentation
Other Physical Features: endothermic ; bilateral symmetry
Gunnison sage-grouse are significantly smaller than greater sage-grouse in size of culmen, carpel, and tarsus, and they weigh approximately 1/3 less (Hupp and Braun 1991, Young et al. 2000). The two species also exhibit genetic differences (Kahn et al. 1999, Oyler-McCance et al. 1999). Additionally, Gunnison sage-grouse males have more elaborate head plumes than do greater sage-grouse males, and they have broader white barring on the tail feathers (Young et al. 2000). The two species also differ in male display behavior; for example, the Gunnison sage-grouse display ends with a tail-shaking motion of the raised tail (absent in greater sage-grouse) (Barber 1991;Young et al. 1994, 2000).
Gunnison sage grouse are a sagebrush (Artemisia) obligate species and also depend on a variety of other grasses and habitats for mating, nesting, and brood-rearing. There are three categories of sage grouse populations: non-migratory, one stage migratory, and two stage migratory. Populations that are non-migratory display limited movement regardless of season. One stage migratory populations prefer different habitat conditions in summer and winter. Three stage migratory populations prefer different habitats for winter, summer, and mating seasons. Mating habitats are often low vegetative density areas with high visibility called leks. Regardless of migratory preferences, all sage grouse populations rely on sagebrush and riparian habitats for feeding and cover. They are found at elevations of 2,200 to 4,300 m.
Range elevation: 2200 to 4300 m.
Range depth: 8.5 (high) m.
Average depth: 4.8 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland
Other Habitat Features: agricultural ; riparian
Habitat and Ecology
Comments: Most information is based on studies of the greater sage-grouse but likely applies to a large degree to Gunnison sage-grouse as well.
Sage-grouse use a variety of habitats throughout the year, but the primary component necessary is sagebrush (Artemisia spp.), especially big sagebrush (A. tridentata) (Braun 1995). Sagebrush is used for hiding and thermal cover as well as for food in the winter (Hupp and Braun 1989).
Leks, used for male displays from mid-March to early June, consist of open areas with good visibility (for predator detection) and acoustics (for transmission of male display sounds).
Female nesting sites typically are in relatively tall and dense stands of sagebrush, about 0.2-8.0 kilometers from the leks. Nest sites also have grass and forbs that provide additional hiding cover. Females with young remain in sagebrush uplands if hiding cover is adequate and if food (succulent forbs and insects) is available. As chicks mature and vegetation in the uplands desiccates, females move their broods to wet meadow areas that retain succulent forbs and insects through the summer (Klebenow 1969, Wallestad 1971). Preferred wet meadow areas also contain tall grasses for hiding and sagebrush stands at least 150 meters wide (Dunn and Braun 1986) along the periphery for hiding and foraging.
From mid-September into November all individuals use upland areas with 20 percent or greater sagebrush cover and some green forbs. As winter progresses and snow cover is extensive (> 80 percent) and deep (> than 30 centimeters), individuals forage in tall sagebrush (> 41 centimeters) in valleys and lower flat areas (Hupp and Braun 1989) and roost in shorter sagebrush along ridge tops. Roosting and foraging is typically restricted to south- or west- facing slopes where snow is typically shallower and less extensive (Hupp and Braun 1989). Small foraging areas that have 30-40 percent big sagebrush canopy cover also are important.
Sage-grouse are totally dependent on sagebrush-dominated habitats . Sagebrush is a crucial component of their diet year-round, and sage-grouse select sagebrush almost exclusively for cover . Because sage-grouse habitat and cover requirements are inseparably tied to sagebrush, they will be discussed together.
Breeding: Open areas such as swales, irrigated fields, meadows, burns, roadsides, and areas with low, sparse sagebrush cover are used as leks . Of 45 leks, Patterson  reported that 11 were on windswept ridges or exposed knolls, 10 were in flat sagebrush, 7 were in bare openings, and the remaining 17 were on various other site types. Leks are usually surrounded by areas with 20 to 50% sagebrush cover, with sagebrush no more than 1 foot (30.5 cm) tall.
When not on the lek, sage-grouse disperse to the surrounding areas . Wallestad and Schladweiler  studied habitat selection of male greater sage-grouse in central Montana during breeding season and recorded sagebrush height and canopy cover at 110 daytime feeding and loafing sites of cocks. Eighty percent of the locations occurred in sagebrush with a canopy cover of 20-50%. In another Montana study , sagebrush cover averaged 30% on a cock-use area, and no cocks were observed in areas of less than 10% canopy cover.
Some females probably travel between leks. In Mono County, California, the home range of marked female greater sage-grouse during 1 month of the breeding season was 750 to 875 acres (300-350 ha), enough area to include several active leks .
Nesting: Within a week to 10 days following breeding, the hen builds a nest in the vicinity of the lek . Hens usually nest near the lekking grounds , but some hens have been noted to fly as far as 12 to 20 miles (19-32 km) to favorable nesting sites [56,105]. Distances greater sage-grouse hens traveled from the lek to nest in central Montana in a study by Wallestad and Pyrah  were:
|distance (miles)||0.00-0.50||0.51-1.00||1.01-1.50||1.51-2.00||2.01-3.00||3.01 plus|
|number of nests||1||8||6||1||4||2|
In Idaho, Autenrieth  found the proximity of nests to leks to be:
|distance to lek (miles)||0-0.96||0.96-1.92||1.92-2.88||2.88-3.84||3.84-4.80||4.80-5.76||5.76-6.72|
Quality of nesting habitat surrounding the lek is the single most important factor in population success . Adequacy of cover is critical for nesting. There can be too little: where 13% was the average percent total crown cover on Idaho range, nests were located where average cover was 17%. No greater sage-grouse hens nested in the most arid, open areas with less than 10% total shrub cover. There can be too much: average shrub cover at 87 nest sites was 18.4%, and in more dense cover, sage-grouse did not nest where total shrub cover was greater than 25% . In Utah no nests occurred where threetip sagebrush cover exceeded 35% .
Sagebrush forms the nesting cover for most sage-grouse nests throughout the West with concealment being the basic requirement . Rabbitbrush (Chrysothamnus spp.) is occasionally used for nesting cover with greasewood (Sarcobatus vermiculatus) and shadscale (Atriplex canescens) being rarely used .
Sage-grouse prefer relatively tall sagebrush with an open canopy for nesting. In Utah, 33% of 161 nests were under silver sagebrush that was 14 to 25 inches (36-63.5 cm) tall, while big sagebrush of the same height accounted for 24% of nests . In a threetip sagebrush (A. tripartata) habitat averaging 8 inches (20 cm) in height, hens selected the tallest plants for nesting cover. Similarly, Patterson  reported that in Wyoming, 92% of greater sage-grouse nests in Wyoming big sagebrush were in areas where vegetation was 10 to 20 inches (25-51 cm) tall and cover did not exceed 50%.
Klott and others  measured variables at greater sage-grouse nests by habitat type in Idaho. Shrub cover and height were greater at nest sites than random sites in Wyoming big sagebrush and low sagebrush:
|variable||Wyoming big sagebrush||low sagebrush||crested wheatgrass seeding|
|grass cover (class)*||3||1||2||1||3||4|
|grass height (cm)||9.1||14.5||12.9||15.2||33.4||33.4|
|forb cover (class)*||2||2||1||1||1||3|
|number plant species||11.8||10.0||10.0||10.0||5.5||23.0|
|bare ground (class)*||4||3||5||5||5||4|
|shrub cover (%)||23||31.5||15.1||15.1||3.9||0.0|
|shrub height (cm)||43.2||53.8||16.6||23.7||23.0||0.0|
|Robel pole (cm)**||23||46||7||13||10||19|
|*Cover class values: 1 = trace-1%, 2 = 1.01-5, 3 = 5.01-25%, 4 = 25.01-50%, 5 = 50.01-75% |
** A measure of density 
In Montana, Wallestad and Pyrah  compared sagebrush characteristics around 31 successful and 10 unsuccessful nests. Successful nests had greater than average sagebrush cover surrounding the nest and were located in stands with a higher average canopy cover (27%) than unsuccessful nests (20%). Difference was significant at the 0.005 level. They also found the average height of sagebrush cover over all nests was 15.9 inches (40.4 cm) as compared to an average height of 9.2 inches (23.4) cm in adjacent areas (significant at 0.005 level).
Brood rearing: Sagebrush is an essential part of sage-grouse brood habitat. An interspersion of sagebrush densities, from scattered to dense, are utilized by broods throughout the summer. Broods can be grouped into 2 categories: those that remain in sagebrush types through the summer and those that shift from sagebrush types in mid-summer and later return to sagebrush.
Throughout the summers of 1968-1969 in a study in Montana, areas that received the greatest amount of utilization by greater sage-grouse broods were areas of sagebrush density characterized as scattered (1-10%) and common (10-25%). Scattered sagebrush received heaviest utilization in June. "Common" sagebrush was utilized heavily throughout the summer. "Dense" sagebrush had greatest use during late August and early September; "rare" sagebrush cover received greatest use in July and August.
Combined data for both years of the study at brood sites showed an average sagebrush cover of 14% during June, 12% during July, 10% during August and 21% during September, which reflects the vegetational types utilized by broods during the summer. Height of sagebrush at brood sites ranged mainly between 6 to 18 inches (15.2-45.7 cm) . In 158 Montana locations, young greater sage-grouse broods used areas of low plant height 9 to 15 inches (23-38 cm)) and density, while older broods and adults used areas where plants were taller (7 to 25 inches (18-63.5 cm) .
Early in summer the size of the area used by greater sage-grouse hens with broods in Idaho seemed to depend upon the interspersion of sagebrush types that provided an adequate amount of food and cover. Areas with sagebrush in scattered densities, with occasional clumps in the common to dense categories, appeared to be preferred. In their daily activity, broods tended to use more open sites for feeding and to seek more dense clumps of sagebrush for roosting.
Throughout early summer, daily movements of broods were relatively long, reflecting the great daily activity required of broods to meet their nutritional needs. Klott and others  found that greater sage-grouse hens with broods had the following home ranges in Idaho:
|home range sizes for 4 female greater sage-grouse with broods|
|home range (acres)||habitat type|
|50.8||Wyoming big sagebrush|
|47.4||Wyoming big sagebrush|
|159.9||Wyoming big sagebrush/low sagebrush|
|66.1||Wyoming big sagebrush/low sagebrush|
Cover types used by hens with broods typically had greater availability of forbs during periods of high use, but differences in availability between areas influenced use of cover types, movements, and diets.
In Oregon, the greater sage-grouse hens at Jackass Creek selectively used sites with forb cover greater than typically found there and similar to that generally available to broods at Hart Mountain National Antelope Refuge. This amount of forb cover (12-14%) may represent the minimum needed for greater sage-grouse brood habitat in Oregon .
Succulence of their favored foods appears to be a key to sage-grouse movements . As plants mature and dry, the grouse move to areas still supporting succulent vegetation. A delay in maturing of forbs has a noticeable effect on bird movements .
Broodless: A study by Gregg and others  in Oregon revealed differences in chronology of summer movements and cover types used between broodless greater sage-grouse hens and greater sage-grouse hens with broods. Broodless hens gathered in flocks and remained separate from but in the vicinity of hens with broods during early summer. However, broodless hens moved to meadows earlier in summer and used a greater diversity of cover types than hens with broods perhaps because dietary needs of broodless hens might be less specific than those of hens with broods.
Winter: A winter-use area appears to be both a key habitat segment and a major factor in sage-grouse distribution over a large area . The best winter habitat is below snowline, where sagebrush is available all winter . Dalke and others  reported wintering grounds of greater sage-grouse in Idaho were usually where snow accumulation was less than 6 inches (15 cm). In areas of deep snow, greater sage-grouse winter where sagebrush has grown above the snow level .
Sage-grouse appear to select areas of little or no slope. In a Colorado study, nearly 80% of Gunnison sage-grouse winter use of 500 square miles (1,252 km2) of sagebrush was on less than 35 square miles (87 km2): on flat areas where sagebrush projected above the snow, or on south- or west-facing sites of less than 5% slope, where sagebrush was sometimes quite short but still accessible . In Montana, prime wintering areas were flat, large expanses of dense sagebrush; winter home ranges of 5 greater sage-grouse females in Montana varied from 2,615 to 7,760 acres (1,050-3,100 ha) during 2 different years .
Winter-use areas are determined by amount of snow rather than affinity to a particular site . Majority of winter observations are in sagebrush with more than 20% canopy coverage. Species and subspecies of sagebrush that seem to be preferred by grouse in the winter are black sagebrush, low sagebrush, and some subspecies of big sagebrush [4,33].
Associated Plant Communities
Sage-grouse are obligate residents of the sagebrush (Artemisia spp.) ecosystem, usually inhabiting sagebrush-grassland or juniper (Juniperus spp.) sagebrush-grassland communities. Meadows surrounded by sagebrush may be used as feeding grounds . Use of meadows with a crown cover of silver sagebrush (A. cana) is especially important in Nevada during the summer .
Sage-grouse occur throughout the range of big sagebrush (A. tridentata), except on the periphery of big sagebrush distribution or in areas where it has been eliminated . Sage-grouse prefer mountain big sagebrush (A. t. ssp. vaseyana) and Wyoming big sagebrush (A. t. spp. wyomingensis) communities to basin big sagebrush (A. t. spp. tridentata) communities.
Sagebrush cover types other than big sagebrush can fulfill sage-grouse habitat requirements; in fact, sage-grouse may prefer other sagebrush cover types to big sagebrush. Sage-grouse in Antelope Valley, California, for example, use black sagebrush (A. nova) cover types more often than the more common big sagebrush cover types . Drut and others  found hens with broods on the National Antelope Refuge in Oregon were most frequently found (54-67% of observations) in low sagebrush (A. arbuscular) cover. Desert shrub habitat may also be utilized by sage-grouse .
Sagebrush communities not included in SRM Cover Types but supporting sage-grouse include silver sagebrush and fringed sagebrush (A. frigida) , . Sage-grouse use of less common sagebrush communities (e.g. Bigelow sagebrush (A. bigelovii)) may occur but is not documented in the current literature.
Habitat: Rangeland Cover Types
This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):
More info for the term: cover
SRM (RANGELAND) COVER TYPES :
107 Western juniper/big sagebrush/bluebunch wheatgrass
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
316 Big sagebrush-rough fescue
320 Black sagebrush-bluebunch wheatgrass
321 Black sagebrush-Idaho fescue
324 Threetip sagebrush-Idaho fescue
401 Basin big sagebrush
402 Mountain big sagebrush
403 Wyoming big sagebrush
404 Threetip sagebrush
405 Black sagebrush
406 Low sagebrush
407 Stiff sagebrush
408 Other sagebrush types
414 Salt desert shrub
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
More info for the term: cover
SAF COVER TYPES :
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
KUCHLER  PLANT ASSOCIATIONS:
K024 Juniper steppe woodland
K038 Great Basin sagebrush
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES30 Desert shrub
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
This species is basically nonmigratory in some areas, but in other areas it makes limited seasonal movements among different habitats. For example, in San Juan County, Utah, females nested within 3.3 km of lek sites, broods remained within 3.0 km of nest sites, and males stayed within 4.0 km of the nearest lek site (Lupis 2005). Females without broods traveled the farthest, moving up to 7.4 km from the lek on which they were captured (Lupis 2005). In the Gunnison basin, 20 of 25 nests were within 6.4 km of the lek on which the female was captured (Young 1994, Apa 2004, Gunnison Sage-grouse Rangewide Steering Committe 2005). Overall, the vast majority of nests are within 6.4 km of the lek of capture (Gunnison Sage-grouse Rangewide Steering Committee 2005). Longer movements sometimes occur. Movements of up to 24 km have been observed in individual Gunnison sage-grouse in the Gunnison Basin population (Phillips 2010, pers. comm., cited by USFWS 2010).Sage-grouse sometimes move 30 km or more between winter range and nesting areas (see Gunnison Sage-grouse Rangewide Steering Committee 2005).
In greater sage-grouse (Centrocercus urophasianus) in northwestern Colorado, median dispersal distance from place of hatching to place of breeding or attempted breeding was 8.8 km for 12 females and 7.4 km for 12 males (Dunn and Braun 1985).
Gunnison sage grouse have varying food preferences, depending on the life stage and season. In the early summer, insects and forbs are an essential component of the chicks' diet. Insects provide a source of protein for growth and development. In late summer, chicks begin to forage on forbs, and sagebrush is later added to the diet. As sagebrush habitats dry out in colder months, adults and chicks forage on forbs and sagebrush in riparian habitats. In the fall and winter, most sage grouse consume mainly sagebrush leaves. Certain types of sagebrush can be preferred based on protein levels and leaf textures. Gunnison sage grouse do not have muscular gizzards, so it is difficult for them to grind and digest seeds.
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; fruit
Foraging Behavior: stores or caches food
Primary Diet: omnivore
Comments: Sage-grouse diet consists of almost exclusively sagebrush in winter; during the remainder of the years Gunnison sage-grouse eat sagebrush, forbs, and insects (Wallestad et al. 1975, Schroeder et al. 1999, Young et al. 2000). Insects are important in the diet of chicks during their first three weeks of life; subsequently, forbs and sagebrush increase in importance (see Gunnison Sage-grouse Rangewide Steering Committee 2005).
Adults: The importance of sagebrush in the diet of adult sage-grouse is impossible to overestimate. Numerous studies have documented its year-round use by sage-grouse [9,23,24,72,92,108,110,124,125]. A Montana study, based on 299 crop samples, showed that 62% of total food volume of the year was sagebrush. Between December and February it was the only food item found in all crops. Only between June and September did sagebrush constitute less than 60% of the greater sage-grouse diet . Sage-grouse select sagebrush species differentially. Greater sage-grouse in Antelope Valley, California, browsed black sagebrush more frequently than the more common big sagebrush . Young and Palmquist  state the browse of black sagebrush is highly preferred by greater sage-grouse in Nevada. In southeastern Idaho, black sagebrush was preferred as forage .
Among the big sagebrush subspecies, basin big sagebrush is less nutritious and higher in terpenes than either mountain or Wyoming big sagebrush. Sage-grouse prefer the other two subspecies to basin big sagebrush . In a common garden study done in Utah, Welch, Wagstaff and Robertson  found sage-grouse preferred mountain big sagebrush over Wyoming and basin big sagebrush. However, when leaves and buds of the preferred species became limited, the birds shifted to the lesser-liked plants. The authors concluded the birds, while expressing preference, are capable of shifting their eating habits.
Sage-grouse lack a muscular gizzard and cannot grind and digest seeds; they must consume soft-tissue foods . Apart from sagebrush, the adult sage-grouse diet consists largely of herbaceous leaves, which are utilized primarily in late spring and summer . Additionally, sage-grouse use perennial bunchgrasses for food .
Sage-grouse are highly selective grazers, choosing only a few plant genera. Dandelion (Taraxacum spp.), legumes (Fabaceae), yarrow (Achillea spp.) and wild lettuce (Lactuca spp.) account for most of their forb intake [6,110]. Martin  found that from July to September, dandelion comprised 45% of greater sage-grouse intake; sagebrush comprised 34%. Collectively, dandelion, sagebrush, and two legume genera (Trifolium and Astragalus) contributed more than 90% of the sage-grouse diet. Insects are a minor diet item for adult sage-grouse. Martin and others  reported insects comprised 2% of the adult greater sage-grouse diet in spring and fall and 9% in summer. Sagebrush made up 71% of the year-round diet.
Prelaying females: Herbaceous dicots are used heavily by females before egg laying and may be essential for sage-grouse nutrition because of their high protein and nutrient content .
Favored foods of prelaying and brood-rearing greater sage-grouse hens in Oregon are :
common dandelion (Taraxacum officinale)
goatsbeard (Tragopogon dubuis)
western yarrow (Achillea millifolium)
prickly lettuce (Lactuca serriola)
sego lily (Calcochortus macrocarpus)
In southeastern Oregon, Barnett and Crawford  studied prelaying nutrition of greater sage-grouse hens, March to April, 1990 and 1991.
|frequency of occurrence among crops||relative dry weight|
|big sagebrush 1990 |
(N = 7) %
|low sagebrush 1990 |
(N = 13) %
|low sagebrush 1990 |
(N = 22) %
|big sagebrush 1990 |
(N = 7) %
|low sagebrush 1990 |
(N = 13) %
|low sagebrush 1990 |
(N = 22) %
|desert-parsley (Lomatium spp.)||86||92||68||7||16||8|
|hawksbeard (Crepis spp.)||57||62||37||11||14||3|
|long-leaf phlox (Phlox longifolia)||86||92||55||12||4||2|
|mountain dandelion (Agoseris spp.)||28||69||11||2||4||1|
|clover (Trifolium spp.)||0||31||18||0||4||1|
|everlasting (Antennaria spp.)||43||69||41||8||3||2|
|woollypod milk-vetch (Astragalus purshii)||57||31||9||2||<1||<1|
|buckwheat (Eriogonum spp.)||14||8||0||2||<1||0|
|arcane milk-vetch (A. obscurus)||0||31||5||0||2||<1|
|buttercup (Ranunuculus spp.)||0||8||0||0||<1||0|
|other phlox (Phlox spp.)||14||15||18||<1||<1||<1|
|blue-eyed Mary (Collinsia spp.)||0||38||9||0||<1||<1|
|bluebells (Mertensia spp.)||0||0||5||0||0||<1|
|larkspur (Delphinium spp.)||0||0||5||0||0||<1|
|rockcress (Arabis spp.)||14||0||0||<1||0||0|
Juveniles: In their 1st week of life, sage-grouse chicks consume primarily insects, especially ants and beetles . Their diet then switches to forbs, with sagebrush gradually assuming primary importance. In a Utah study, forbs composed 54 to 60% of the summer diet of juvenile sage-grouse, while the diet of adult birds was 39 to 47% forbs .
In a Wyoming study, Johnson and Boyce  evaluated effects of eliminating insects from the diet of newly-hatched greater sage-grouse chicks. All chicks hatched in captivity and not provided insects died between the ages of 4 and 10 days, whereas all chicks fed insects survived the 1st 10 days. Captive greater sage-grouse chicks required insects for survival until they were at least 3 weeks old. Greater sage-grouse chicks > 3 weeks old survived without insects, but their growth rates were lowered significantly, indicating insects were still required for normal growth after 3 weeks of age. As quantity of insects in the diet increased, survival and growth rates also increased up to 45 days, the length of the experiment.
In a study conducted in Idaho, Klebenow and Gray  measured food items for juvenile greater sage-grouse for each age class, classes being defined by weeks since birth. In the 1st week insects were very important - 52% of the total diet. Beetles, primarily family Scarabaeidae, were the main food item. Beetles were taken by all other age classes of chicks, but in smaller amounts. All ages fed upon ants and while the volume was generally low, ants were found in most of the crops. After week 3, insect volume dropped and stayed at a lower level throughout all the age classes, fluctuating but always under 25%.
Forbs were the major plant food of the chicks. Harkness gilia (Linanthus harknessii) was the main forb species in the 1st week and then steadily decreased. It was not found in the diet after 6 weeks. Loco (Arabis convallarius) and common dandelion were important food items for most of the collection period and occurred with generally high frequencies. Common dandelion was the most abundant food item and the mainstay of the sage-grouse chicks. At 6 weeks of age, goatsbeard reached its peak in the diet and sego lily was found in greatest volume a week later. These 5 species were the most important forbs.
The only shrub of importance was big sagebrush. It appeared in the diet at 4 weeks of age and as the ages progressed, the volume increased steadily. These 6 plants comprised 83% of the total sample and are listed in order of decreasing percent total volume :
|food item||part||% of total|
|common dandelion||buds, seeds||80|
|Sego lily||buds, capsules||100|
With plants like common dandelion and goatsbeard, all aboveground parts of the plant were sometimes eaten. The stems, however, were not of main importance. The reproductive parts, mainly buds, flowers, and capsules, were the only parts taken from some of the other species. Conversely, leaves were the only parts of sagebrush found in the crops. Leaves and flowers of the species listed above and other dicots contained higher amounts of crude protein, calcium, and phosphorus than sagebrush and may be important in greater sage-grouse diets for these reasons .
In a central Montana study, Peterson  analyzed crop contents of juvenile greater sage-grouse. Data indicate increasing use of sage species and decreasing use of insects. Percent frequency and percent volume of food items commonly utilized by 1- to 12-week-old greater sage-grouse collected during 1966 and 1968 were:
|1-4 n = 26||5-8 n = 47||9-12 n = 54|
|food item||%Freq/(%Vol)||%Freq /(%Vol)||%Freq /(%Vol)||Total1 % Freq/ (%Vol)|
|curlycup gumweed (Grindelia squarrosa)||9/trace||28/3||39/4||25/2|
|alfalfa (Medicago sativa)||--||21/2||22/2||14/1|
|littlepod false flax (Camelina microcarpa)||9/1||2/trace||--||4/trace|
|skunkbush sumac (Rhus trilobata)||--||3/3||--||1/1|
|wheat (Triticum aestivum)||--||--||9/3||3/1|
|Ttotal volumes of trace material||2||1||1||1|
|TOTAL PERCENT PLANT VOLUME||70||76||83||76|
|TOTAL VOLUMES OF TRACE MATERIAL||8||--||--||3|
|TOTAL PERCENT ANIMAL VOLUME||30||24||17||24|
Five most preferred1 plant species in each 2-week age division of juvenile sage-grouse, 1966 and 1968 are listed below. Note only 1 sagebrush species is listed and that it is not preferred until weeks 7-8 :
|food item||1-2 |
|common pepperweed (Lepidium densiflorum)||4||2||-||-||-||-||-|
|littlepod false flax||-||4||-||-||-||-||-|
|American vetch (Vicia americana)||1||-||-||-||-||-||-|
|Breitung blue lettuce (Lactuca pulchella)||-||-||1||-||-||-||-|
|sedges (Carex spp.)||-||-||-||-||-||-||1|
Water: Sage-grouse apparently do not require open water for day-to-day survival if succulent vegetation is available. They utilize free water if it is available, however. Sage-grouse distribution is apparently seasonally limited by water in some areas. In summer, sage-grouse in desert regions occur only near streams, springs, and water holes. In winter in Eden Valley, Wyoming, sage-grouse have been observed regularly visiting partially frozen streams to drink from holes in the ice .
Light to moderate grazing in the early season can promote forb and arthropod abundance in both upland and riparian habitats, whereas intense foraging can cause detrimental decreases in sagebrush distribution and promote introduction of invasive grasses. Gunnison sage grouse are infected with some kinds of blood parasites (Haemoproteus).
Ecosystem Impact: keystone species
- sagebrush (Artemisia tridentata )
- blood parasites (Haemoproteus)
Sage grouse are easy targets due to their large size and inability to run fast. Males are also ostentatious and can be spotted by predators relatively easily. Females and chicks have a lower mortality rate due to smaller mass and the ability to camouflage with their surroundings. There has been research showing that a decrease in black tailed jackrabbit (Lepus californicus) populations has led to an increase in predation of sage grouse. In other regions, decreases in preferred prey populations have resulted in a shift of preferred prey to sage grouse. Dense, tall vegetation can help provide cover to protect nests from predators. Coyotes (Canis latrans), ground squirrels (Sciuridae), and American badgers (Taxidea taxus) are common nest predators. Sage grouse are also a popular game bird. Colorado and Utah have prohibited hunting for sage grouse in certain areas to protect dwindling population numbers.
- golden eagles (Aquila chrysaetos)
- coyotes (Canis latrans)
- foxes (Vulpes)
- American badgers (Taxidea taxus)
- magpies (Pica hudsonia)
- weasels (Mustela)
- ravens (Corvus corax)
- red-tailed hawks (Buteo jamaicensis)
- ferruginous hawks (Buteo regalis)
Anti-predator Adaptations: cryptic
Predators are commonly believed to negatively impact sage-grouse populations and of most importance is timing of death. Nest loss to predators is most important when potential production of young and recruitment are seriously impacted . Lack of adequate nesting and brooding cover may account for high juvenile losses in many regions .
Studies by Gregg and others , Delong and others  in Oregon, and Sveum and others  in Washington suggest that nest success is related to herbaceous cover near the nest site. Taller, more dense herbaceous cover apparently reduces nest predation and likely increases early brood survival . Although predators were the proximate factor influencing nest loss, the ultimate cause may relate to the vegetation available to nesting sage-grouse . Tall dense vegetation may provide visual, scent, and physical barriers between predators and nests of ground-nesting birds. Greater amounts of both tall grass and medium-height shrub cover were associated collectively with a lower probability of nest predation . In a series of Nevada studies, artificial nest predation experiments were conducted. Artificial nests experienced 100% mortality with the loss of 1,400 eggs in 200 simulated sage-grouse nests in 2 weeks in 1 study, 84% of the nests were destroyed in 3 days in another study, while just 3% of the nests were destroyed in 10 days in an area of significantly better cover (t test, P < 0.05) .
Generally, quantity and quality of habitats used by sage-grouse control the degree of predation. Thus, predation would be expected to be most important as habitat size and herbaceous cover within sagebrush decreases .
A decline in preferred prey may also result in increased predation on sage-grouse. Kindschy  suggested that in southeastern Oregon, a decline in black-tailed jackrabbit (Lepus californicus) numbers may have caused predators to switch to sage-grouse as their primary prey.
Predator species: Coyote (Canis latrans) [69,116], bobcat (Lynx rufus) , badger (Taxidea taxus) , falcons (Falconidae) , and hawks, kites, and eagles (Accipitridae) [9,40,96] prey on adult and juvenile sage-grouse. Crows and ravens (Corvus spp.) and magpies (Pica spp.) consume juvenile birds [69,116]. Coyote, ground squirrels (Spermophilus spp.), and badger are the most important mammalian nest predators. Among bird species, magpies and ravens commonly prey on sage-grouse nests [63,66,124].
Sage-grouse are a popular game bird. Mortality due to hunting is generally considered to be compensatory [19,34] and replacive , where until mortality reaches a "threshold value" it has no effect on population levels. Autenrieth and others  state data are not available to suggest that closed or restricted hunting seasons will materially affect overall sage-grouse population levels on their primary range.
In a study on hunting in a low density greater sage-grouse population in Nevada, Stigar  concluded low sage-grouse populations may be a result of factors other than hunting. Protecting 1 sage-grouse population from hunting while doubling the birds harvested in a 4-year period on another population showed that despite low recruitment, both populations increased to nearly the same density.
In an Oregon study, no relationship existed between the rate of summer recruitment (chicks/adult) and harvest by hunters. Nor was any significant relationship found between the size of the fall harvest and population trends during the subsequent spring. Decline in greater sage-grouse populations was apparently unrelated to harvest because no relationship was found between the magnitude of the harvest and the size of subsequent spring populations .
Braun and Beck  demonstrated no relationship between harvest rates and subsequent breeding population size in Colorado. Gill , also in a Colorado study, concluded that hunter harvest had little effect on spring populations of male Gunnison sage-grouse.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 6 - 20
Comments: Gunnison Sage-grouse Rangewide Steering Committee (2005) identified eight extant populations (these are metapopulations, each of which includes gaps in occupied habitat).
2500 - 10,000 individuals
Comments: As of 2009, the total population was estimated to be about 4,400 individuals, with about 3,800 of these in the Gunnison Basin, Colorado (all other populations had estimated population sizes of fewer than 200 individuals.(USFWS 2010).
Sage-grouse are strong fliers but tend to travel slowly on foot unless threatened, in which case the grouse tend to hide or fly (less likely to run long distances) (Patterson 1952, Schroeder et al. 1999).
Habitat-related Fire Effects
Fire may be beneficial or detrimental to sage-grouse, depending on the particular setting and location relative to seasonal changes . Sage-grouse use sagebrush of different age classes and stand structure for different life history events at different seasons. Fire effects on these different sagebrush habitats vary and are treated separately. Additionally, some sage-grouse populations are migratory and others sedentary. Whether a population is migratory or not is dependent on precipitation, vegetation, and elevation [28,29]. Where precipitation is less than 10.4 inches/year (260 mm/yr)  or where sage-grouse move more than 10 miles (16 km)  to a seasonal range, populations are considered migratory. Plant communities that support these populations reflect differences in precipitation and elevation and may exhibit different fire effects. Where there is sufficient literature, differences in migratory and sedentary populations relative to HABITAT RELATED FIRE EFFECTS are discussed.
Breeding: Leks, where breeding occurs, are usually small open areas from 0.1 to 10.0 acres (0.4-4.0 ha) in size, but may be as large as 100 acres (40.5 ha) . Effects of fire on the lek itself are not as much a concern as they are on the area around the lek . This area is used by sage-grouse for loafing, feeding, and escape cover [4,73]. A study by Wallestad and Schladweiler  in Montana recorded sagebrush cover and height at 110 daytime sites of cock greater sage-grouse and found 80% of the locations occurred in sagebrush with a canopy cover of 20-50%. Sagebrush canopy cover for the 110 sites averaged 36%. Also in Montana, Eng and Schladweiler  found that a cock-use area during the breeding season had canopy coverage of sagebrush averaging 30%. In Idaho, Autenrieth  found 80% of cock greater sage-grouse locations occurred in sagebrush stands of 20-50% canopy coverage.
An Idaho study by Martin , after wildfires in 1981, found greater sage-grouse continued to use leks located within extensive burns. Attendance of males at burned leks did not decrease (after adjusting for population declines) despite extensive reduction of surrounding shrub cover. During this study, males and females attended leks in spite of the loss of vegetative cover immediately surrounding leks. Greater sage-grouse seemed to adapt to loss of sagebrush in travel corridors and in principal breeding season habitat of cocks. Cocks and hens appeared to feed, loaf, and roost primarily in unburned habitat and fly into burned leks. Martin found greater sage-grouse attended burned and unburned leks within perimeters of large burns and suggested there are 2 factors that account for why greater sage-grouse attended burned leks in his study area: 1) The summer wildfire burn occurred in a mosaic pattern and left many unburned islands, so abundant nesting habitat was available near all leks within the burn. 2) The long-term population within the burn area was well below average population when the burn occurred, allowing the smaller unburned portions of the study area to supply necessary habitat requirements. Gates  observed greater sage-grouse displaying and mating on a burned area in Idaho during the 1st 2 breeding seasons following a burn. These observations also took place during a population decline.
Fischer  studied lek attendance patterns after a late-summer prescribed burn on the upper Snake River Plain of southwestern Idaho. He could detect no differences attributable to fire after 2 years. However, an additional year of data on lek attendance and further analysis of lek data from Fischer's study provide evidence that fire had a negative influence on the breeding population in the treatment area . The notion that fire had negative effects on the greater sage-grouse breeding population in the treatment area is supported by 4 findings: 1) The treatment area had a higher loss of leks (-58%) than did the control area (-35%). 2) Changes in attendance in major leks by males were similar in treatment and control areas during the preburn period but the treatment area had a greater decline in attendance (-90%) than the control area (-63%) during the postburn period. 3) Average lek attendance at the 2 largest leks in both areas was greater in the treatment (67 males) than the control (59 males) area during the preburn period. However, the situation reversed during the postburn period, and average attendance at the 2 treatment leks (22 males) was less than the average attendance at the control leks (36 males). 4) The mean number of male greater sage-grouse per lek was similar in treatment and control areas during the preburn period but was much lower in the treatment area (6 males) than in the control area (17 males) during the postburn period.
In a study in Idaho, Connelly and others  found some greater sage-grouse leks persist even after sagebrush areas have been burned. Data from the study suggest that greater sage-grouse continue to use leks in altered areas because some hens nest successfully under nonsagebrush plants. The authors caution that persistence of leks in burned areas should not be interpreted as evidence that fire has little effect on greater sage-grouse populations. Greater sage-grouse use of nonsagebrush shrubs for nest sites may allow populations to persist at low levels in a burned area until the area recovers. However, this behavior may only slow, but not prevent, the birds' ultimate disappearance from the burned area.
Leks used by migratory populations of sage-grouse appear to be more susceptible to deleterious HABITAT RELATED FIRE EFFECTS because they are usually dominated by Wyoming big sagebrush  which re-establishes slowly following fire . Degradation of breeding range because of fire, drought, grazing, or herbicides will likely reduce sage-grouse populations because of low nesting effort, low nest success, or poor chick survival. Regardless of the method used to eliminate or reduce sagebrush cover in xeric sage-grouse breeding habitat, these actions have the potential for reducing breeding populations of grouse. It is recommended that prescribed burning be avoided in relatively xeric habitats used by breeding migratory sage-grouse. If a Wyoming big sagebrush habitat type supports a breeding population of sage-grouse, it is recommended a high priority be given to suppressing wildfires in these habitats during drought .
Nesting: After mating, hens disperse to nest . Most nest near leks, and areas within a 1.9 mile (3 km) radius of leks is considered the most important for nesting . Some hens may fly as far as 32 to 48 miles (20-30 km) to nest . Nesting habitat is often a belt between summer and winter range . Often there is a complex of habitat types centered around a lek. In nonmigratory populations of sage-grouse, this complex may provide for year-round needs of the birds. In migratory populations, this suite of habitat types often includes breeding, nesting, early brood-rearing, and winter habitats, and sage-grouse migrate to fill their summer needs .
Gill  found that Gunnison sage-grouse nested under all types of shrub cover on his study area in Colorado, but preferred sagebrush, with 92.3% of 117 nests located under sagebrush. Shrub heights preferred for nesting varied from 11.8 to 23.6 inches (30-60 cm), with 7.9 to 31.5 inches (20-80 cm) adequate and shrub canopy coverage > 17% . In Idaho, Klebenow  found no greater sage-grouse nested in the most arid, open areas (< 10% total shrub cover, mean shrub canopy coverage at 87 nest sites = 18.4%). In more dense cover, greater sage-grouse did not nest where total shrub cover was > 25% .
Complete removal of sagebrush in burned areas could reduce nesting, hiding, and wintering cover for sage-grouse . Sage-grouse show fidelity to leks and/or nesting areas [13,48]. A study on the Big Desert, in Idaho, by Fischer and others , found that because greater sage-grouse hens appear to seek suitable habitat within a relatively small area, nest area fidelity may reduce nesting if large areas of nesting habitat are destroyed. Hens may nest in unsuitable areas and experience lower nest success .
Klebenow  states the cover shrubs provide is necessary for nesting greater sage-grouse, and complete removal of shrubs can only result in elimination of greater sage-grouse from the area. Fire eliminates potential winter and nesting habitat according to Robertson  and Fischer . Connelly and Braun  feel fire may negatively impact sage-grouse populations by eliminating or fragmenting relatively large blocks of wintering or nesting habitat. During the 1st few years after burning, nesting habitat is essentially destroyed .
Fischer  studied the effects of fire on migratory greater sage-grouse breeding, nesting, and brood-rearing habitat in southeastern Idaho. Nests inside the burned area were only found in unburned patches, suggesting that removal of sagebrush by fire reduces nesting cover for grouse. Although no immediate differences in use of burned and unburned habitat were demonstrated in this study for 3 postfire years, long-term response of nesting greater sage-grouse to fire may be dependent on both the scale of sagebrush removal and intensity of fidelity to nesting areas. Greater sage-grouse that show nesting-area fidelity may subsequently return to the same area and attempt a nest even after the habitat has been manipulated. Attenuation of nest-area fidelity as site-tenacious individuals die may decrease production in the burned area. Fire may also reduce the number of suitable nesting sites by removing shrub cover for nests.
Brood rearing: The single unifying theme threatening sage-grouse across their geographical range is the universality of brood habitat loss . Drought and increased fire frequency may be the primary agents causing a decline in brood-rearing habitat for sage-grouse. Moreover, an unfavorable situation due to drought and an increase in wildfire may have been made worse in many areas by vigorous prescribed burning . Brood habitat typically has 15-25% shrub canopy closure but at least 10-20% cover of live forbs and grasses . In southern Idaho, the percent canopy cover of big sagebrush at brood sites was 8.5%, significantly less than the average for the entire area, 14.3% .
Broods are tied to food in addition to cover . After hatching, before chicks can fly and when mortality is highest [4,92], broods need food in close proximity to escape cover . Diet of sage-grouse chicks is chiefly insects early in life, shifting to succulent forbs and shrub foliage as chicks grow older [75,92,95]. Abundant food forbs in close proximity to unburned sagebrush cover could benefit sage-grouse broods by providing additional food with adequate cover, and fire-enhanced flowering may improve forage availability for sage-grouse during the brood rearing period . Sime  states openings in sagebrush canopy may increase forbs and improve brood habitat, and Klebenow  suggests reduced shrub cover on burned sites may increase accessibility of forbs and insects to chicks. In a 2-year study of greater sage-grouse responses to wildfire in Idaho, Martin  found that burning improved habitat for sage-grouse broods. During both postburn years, forb crown cover was significantly higher in burned habitats than in unburned habitats. However, Nelle and others  found that during the 1st few years after burning on a site in southeastern Idaho, greater sage-grouse brood-rearing habitat was not improved.
After a prescribed burn on the Snake River plain of southeastern Idaho, Connelly and others  found no difference in the use of burned and unburned areas by a migratory population of greater sage-grouse. These results suggest fire does not improve brood-rearing habitat in relatively low precipitation areas dominated by Wyoming big sagebrush. The authors were unable to show an increase in forbs following the fire, so fire may have caused an overall decline in brood-rearing habitat, perhaps contributing to the decline in greater sage-grouse population following the fire. Decreased food abundance following fire in the treatment area may have indirectly affected survival by increasing chick movement. Fire in Wyoming big sagebrush has not been reported to increase the length of the growing season for forbs important in the diet of sage-grouse .
Fischer's  research in southeastern Idaho provided evidence for excluding fires that eliminate large blocks of vegetation in brood habitat for migratory greater sage-grouse within xeric regions, because of its impact on insects. Fire appeared to negatively impact insect abundance in 1 of the 3 orders that are most important in sage-grouse diets. The fire created a mosaic of sagebrush areas interspersed with open areas having abundant grasses and forbs, but there was no positive response of greater sage-grouse to the burned area. Broods require food, mainly forbs, in addition to cover. Both may be present in a given acre of land, but the birds also use and appear to seek areas where there is an interspersion of habitat types. They only feed in areas where cover is nearby .
A study by Fischer and others  in southeastern Idaho indicated that short-term effects of a prescribed fire in a xeric environment did not enhance brood-rearing habitat and may have been detrimental to grasshoppers which are important in sage-grouse diets. Gates and Eng  examined use of burned areas by migratory greater sage-grouse after prescribed burns in 1981 and 1982 at the Idaho National Engineering Laboratory. They suggested the patchy burn which occurred could enhance early brood-rearing habitat. If availability of forbs and insects were enhanced on burned areas, then an abundant food supply would be available to broods in close proximity to escape cover.
Summer: Sage-grouse have been reported to be attracted to burn areas during summer [74,84]. Summer habitat is characterized by shrub canopy cover of at least 15% and at least 10% live forb cover . Sagebrush and forbs are essential components of summer sage-grouse habitat . If fire increases availability of photosynthesizing, succulent foods in uplands during the late summer, available sage-grouse habitat may be increased .
Connelly and others  studied migratory greater sage-grouse response to a controlled burn on the upper Snake River Plain of southeastern Idaho. They found fire apparently had no influence on the timing of migration of female greater sage-grouse. However, they found the summer population associated with the burn area declined 75% while that in the control area declined 52%. A similar but more pronounced decline occurred at the largest lek in the burned area. Estimated summer population associated with this lek declined 98% during the 9-year study while the population associated with a similar lek in the unburned area only declined 45%.
Migratory greater sage-grouse in a xeric habitat were studied by Fischer  in Idaho. He found that cover of forbs important in greater sage-grouse summer diets was similar in burned and unburned habitats. Although the fire created a mosaic of sagebrush areas interspersed with open areas having abundant grasses and forbs, there was no movement of greater sage-grouse to the burned area.
Winter: Many researchers [10,45,92] describe winter habitat as probably the most limiting seasonal habitat and thus perhaps the most critical . The majority of winter observations are in sagebrush with more than 20% canopy coverage . Connelly and others  describe sage-grouse wintering habitat as open to moderately dense sagebrush with 10-20% canopy cover. For sedentary populations of sage-grouse, the wintering area is often located within 2 miles (3.2 km) of the strutting ground and nesting area .
Fire may negatively impact sage-grouse populations by eliminating or fragmenting relatively large blocks of wintering habitat  and at times, severe fires destroy important wintering areas for sage-grouse . Sage-grouse show affinity for particular winter ranges [13,45], and known sage-grouse wintering areas should receive priority attention in the control of wildfires . Lack of protection of critical winter habitat has resulted in sage-grouse population declines , and Sime  states it is imperative that winter sage-grouse habitat be protected. Braun and others  caution that complete removal of sagebrush in burned areas could reduce nesting, hiding, and wintering cover for sage-grouse. Gates and Eng  suggest elimination of sagebrush by burning will destroy wintering habitat for grouse.
In areas where winter habitat is limiting, loss of contiguous sagebrush rangeland could negatively impact sage-grouse by removing food and cover. Robertson  conducted a study of a migratory greater sage-grouse population in a xeric habitat in Idaho. He found burning decreased the structural components of greater sage-grouse winter habitat, and use of these areas decreased dramatically. This does not imply that that burning is detrimental to greater sage-grouse with large expanses of winter habitat. If burning takes place on critical winter range, and heavy snow fall covers much of the remaining habitat during the following winter, food and cover may be severely limited. Klebenow  suggests there is little place for fire on wintering sites of migratory greater sage-grouse in xeric habitat since there is nearly a complete reliance on shrubs for food and cover.
Timing of Major Life History Events
Courtship/nesting: Males gather on the lek or strutting grounds, which are small open areas where breeding occurs, in late February to April, as soon as the lek is relatively free of snow. Only a few dominant males, usually 2, breed. Sage-grouse mating behaviors, which are complex, are summarized by Johnsgard . After mating, the hen leaves the lek for the nesting grounds. Clutch size ranges from 6 to 8 eggs; incubation time is 25 to 27 days. Sage-grouse apparently have high rates of nest desertion and nest predation [58,65]. Summarizing data from several sage grouse studies, Gill  found a range of nesting success from 23.7 to 60.3%, with predation accounting for 26 to 76% of lost nests.
Brooding: Chicks fly by 2 weeks of age, although their movements are limited until they are 2 to 3 weeks old . They can sustain flight by 5 to 6 weeks of age. Juveniles are relatively independent by the time they have completed their first molt at 10 to 12 weeks of age .
Seasonal movements: Fall movements to wintering areas are driven by weather conditions and usually occur gradually. After late winter or spring lekking activity, sage-grouse may move to higher elevations or down to irrigated valleys for nesting and feeding. Brooding ranges may be a considerable distance from winter ranges or spring nesting grounds. Schlatterer  reported that in southern Idaho, brooding grounds were 13 to 27 miles (21-43 km) from the nesting grounds. Males may also move long distances over the seasons. During winter in Wyoming, Patterson  recovered a male greater sage-grouse 75 air miles (120 km) from where he had banded it the previous summer.
Direct Effects of Fire
Life History and Behavior
Species can communicate with callings, courtship vocalizations, and feather signaling. Callings can be used to defend territory or to alert others about a threat. Courtship vocalizations help females distinguish the fitness between males during mating season. On the lek, older males will establish and defend their territory by sometimes chasing or fighting other males. Males will often position themselves laterally to females to project the loudest sound. Feather signals are made by the spreading of the tail feathers or the flapping of the wings.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Comments: Activity occurs throughout the year, primarily during daylight hours.
Mating activity peaks shortly after sunrise but occasionally occurs near sunset or during nights with bright moonlight (Schroeder et al. 1999).
During the mating season, sage-grouse forage in morning after breeding activity and in afternoon before roosting or breeding activity (Schroeder et al. 1999). During nesting season, females remain on nests throughout most of the day and night, but they take brief foraging breaks during morning and late afternoon or evening (Girard 1937).
In summer, sage-grouse forage in early morning, loaf during midday, and forage again in the afternoon (Nelson 1955).
In the wild, Gunnison sage grouse have an expected lifespan of 3 to 6 years but can live up to 9 years. Survival rates are low in captivity, and their expected lifespan in captivity is 1 years. This makes rescue efforts difficult for this endangered species. The Colorado Division of Wildlife (CDOW) tried captive rearing and only 11 of 40 chick eggs survived their first year. Despite low survival rate in captivity, CDOW believe that better techniques for raising Gunnison sage grouse have been attained from the process. Sage grouse mortality is higher for males than for females in the wild due to their larger size and flashy appearance. Females and chicks have lower mortality rates because they have a speckled brown and white coloration that functions as camouflage.
Status: wild: 9 (high) years.
Status: wild: 3 to 6 years.
Status: captivity: 1 (high) years.
Gunnison sage grouse display "clumped polygyny," where multiple males compete to mate with females on an arena called a lek. Beginning mid-March through late May, many males begin to migrate to lek sites and often return to the same one each season. Males are very territorial and may defend their lek from intruders. Only one or two males (10-15%) is rewarded with the chance to reproduce with the surveying females. Adult and yearling females often get the opportunity to breed, whereas only select adult males and rarely any yearling males are able to mate.
Leks are often in places with low vegetation and sagebrush cover to maximize visibility. Males compete for females by popping their air sacs and strutting back and forth around the lek for hours. A male can also fan out his tail to try and impress females. Male Gunnison sage grouse have slower courtship displays than their close relatives, greater sage grouse (Centrocercus urophasianus). There are structural differences in mating calls between the two species as well. Females in the Gunnison Basin and northern Colorado can distinguish between male courtship vocalizations. Due to regional differences, females often prefer courtship vocalizations from regions nearby. This preferential breeding behavior creates a reproductive barrier between populations of Gunnison sage grouse that are geographically separated and may be an underlying factor causing species isolation and endangerment. Research has also shown that mating outside of the lek occurs occasionally.
Mating System: polygynous
Males do not participate in either nesting or brood rearing processes. The pre-laying period is from late March to April, when hens search for the ideal nesting sites. Better nesting sites have a greater diversity of forbs and sagebrush for both nutrition and cover. Forbs are a good source of calcium, phosphorous, and proteins that hens feed on during the gestation period to lay healthy eggs. Nesting occurs from mid-April to June and hens may then migrate to locations far from the lek to find optimal nesting conditions. Hens select nest sites that have adequate sagebrush and grass to provide cover from predators while the hen is incubating the eggs. Hens are loyal to successful nesting areas and will return season after season.
Hens have one brood per season and lay 6 to 8 eggs that hatch in 25 to 27 days. Small clutch sizes and annual mating opportunities have resulted in decreasing population numbers. Despite the small clutch size, most eggs hatch in June. Chicks are precocial and weigh 30 g at birth on average. Soon after hatching, they leave the nesting area for a riparian habitat to feed on insects. Chicks are able to make short flights and feed on their own by 2 to 3 weeks of age. They may follow their mothers until the fall. Chicks are able to sustain flight by 5 to 6 weeks of age and are considered independent at 10 to 12 weeks of age. In the winter, chicks and mothers separate into sexually segregated flocks and may be reunited in the spring when flocks migrate to lek sites to compete for mates.
Breeding interval: Gunnison sage grouse breed annually in the spring.
Breeding season: Gunnison sage grouse breed from April to June.
Range eggs per season: 6 to 9.
Average eggs per season: 7.
Range time to hatching: 25 to 27 days.
Range fledging age: 2 to 3 weeks.
Range time to independence: 10 to 12 weeks.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Besides reproduction, males take no part in nest building or brood rearing. Females look for nesting sites that have adequate coverage and resources to raise chicks. Herbaceous dicots are an important dietary requirement for egg laying and provide a rich source of protein and phosphorous. Females often return to the same nesting sites annually if nest success rates are high. Chicks follow the mothers shortly after hatching. Hens offer a limited amount of parental care and chicks are mostly on their own for food procurement.
Parental Investment: precocial ; female parental care ; pre-hatching/birth (Provisioning: Female); pre-weaning/fledging (Provisioning: Female); pre-independence (Provisioning: Female)
The life cycle involves several significant stages, minimally including wintering, lek attendance, nesting, and brood rearing.
In Colorado and likely Utah, males display on leks from mid-March through late May, depending on elevation and conditions (Rogers 1964). Females visit leks, mate with one or more males, then depart to begin nesting. Clutch size averages around 6-7 (Young 1994, USFWS 2010). Incubation, by the female alone, lasts about 4 weeks. Hatching begins around mid-May and may extend into July; the peak usually is in mid-June (Gunnison Sage-grouse Rangewide Steering Committee 2005). Chicks leave the nest with the female shortly after hatching. Females infrequently renest if they lose their first nest.
In greater sage-grouse (Centrocerus urophasianus), yearling males are capable of breeding, but most breeding is done by older males; yearling females often breed but somewhat less frequently than do older females (see Schroeder et al. 1999). Typical sage-grouse life span is 3-6 years, sometimes up to 9 years (Connelly et al. 2004).
Molecular Biology and Genetics
Barcode data: Centrocercus minimus
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Statistics of barcoding coverage: Centrocercus minimus
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
Habitat fragmentation, invasive plant species, and low vegetative diversity are the main issues endangering Gunnison sage grouse populations. The Colorado Parks and Wildlife is working with the Colorado Cattlemen's Association, Gunnison County, and the Bureau of Land Management to better understand factors impacting Gunnison sage grouse populations. The Bureau of Land Management (BLM) has been working with the Candidate Conservation Agreement (CCA) to try and conserve public lands that have sage grouse populations. Locals have also shown an interest in protecting the remaining populations. In 2010, the US Fish and Wildlife Service (FWS) listed the sage grouse as "warranted but precluded" under the Endangered Species Act to indicate that, although the species is not of top priority, they play an important ecological role. By listing the sage grouse, it has helped raise awareness and protect sagebrush habitats from further fragmentation.
US Migratory Bird Act: protected
US Federal List: endangered
CITES: no special status
State of Michigan List: endangered
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Range and distribution have contracted; now restricted to several small areas in southwestern Colorado and southeastern Utah; threatened primarily by loss, fragmentation, and degradation of sagebrush habitat.
Status: Proposed Endangered
Lead Region: Mountain-Prairie Region (Region 6)
Where Listed: entire
For most current information and documents related to the conservation status and management of Centrocercus minimus, see its USFWS Species Profile
U.S. Federal Legal Status
Global Short Term Trend: Relatively stable (=10% change)
Comments: Trend over the period 2001-2010 was relatively stable, but this trend was driven primarily by the relatively stable trend in the largest (Gunnison basin) population; the other populations declined (USFWS 2010)
Global Long Term Trend: Unknown
Comments: The current range is thought to be only about 10 percent of the historical potential habitat area (Schroeder et al. 2004). Maximum historical range was about 55,350 square kilometers (not all of this was simultaneously occupied); current occupied habitat is about 3,795 square kilometers (Gunnison Sage-grouse Rangewide Steering Committee 2005). Population size has clearly declined, but degree of decline in population size is not well established (Gunnison Sage-grouse Rangewide Steering Committee 2005).
Degree of Threat: High
Comments: USFWS (2010) summarized threats as follows (very slightly modified).
Current and future direct and functional loss of habitat due to residential and road development in all populations is the principal threat to the Gunnison sage-grouse. Other threats from human infrastructure such as fences and powerlines 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 exacerbate the fragmentation that has already occurred in Gunnison sagegrouse 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 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. 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 habitat-based threats 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 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 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 for both the Gunnison sagegrouse 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 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. 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 the Colorado Division of Wildlife (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 and the species as a whole. 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.
In 1995 a working group was formed and, in 1998, a conservation plan identified over 200 actions (BLM 1999, J. R. Young in litt. 1999). By 2004 over 95% of the population was covered by local working groups' conservation plans (J. R. Young in litt. 2005). While the success of such local efforts may be controversial, hunting has ceased and significant gains have been made in land protection through conservation easements and land acquisitions (J. R. Young in litt. 2005). Current actions include lek enhancement, riparian area restoration, nest habitat treatments, improved livestock management, nest predator research, and education (J. R. Young in litt. 1999). Education measures include sponsored grouse viewing, information brochures and talks given in local schools and fairs (W. Martinson in litt. 2003). Radio-telemetry and graduate research is helping to determine winter habitat use, and lek sites have been protected (W. Martinson in litt. 2003). Hunting of the species has been stopped (C. Braun in litt. 2005, J. R. Young in litt. 2005). In 2005 state and federal employees drafted a 'Rangewide Plan' and have begun contact with local landowners to present voluntary conservation agreements (J. R. Young in litt. 2005). Conservation Actions Proposed
Restore and improve habitat, while continuing work to prevent further loss and fragmentation. Support its listing on the Endangered Species Act. Continue population monitoring at key sites. Conduct further ecological research, focussing on survival, dispersal and habitat use at different life stages. Encourage and facilitate the implementation of local and range-wide management plans. Reduce disturbance, especially at active leks. Investigate the possibility of using translocations to augment small populations. Continue work to raise awareness of key issues among stakeholders.
Management Requirements: In San Juan County, Utah, Prather (2010) recommended that habitat restoration efforts "focus on retaining existing sagebrush cover and establishment of sagebrush, forb and grass cover within Conservation Reserve Program fields." Prather (2010) also discussed how power poles benefit avian predators on sage-grouse, and she evaluated methods for deterring predatory birds from perching on power poles.
In Utah, Lupis et al. (20060 found that Gunnison sage-grouse used Conservation Reserve Program (CRP) lands for nesting, brood-rearing, and summer habitat, but these areas were not selected in greater proportion than their availability on the landscape. Most radio-tracked sage-grouse avoided CRP fields when livestock were present (one exception to this was a hen with a brood). Lupis et al. (2006) concluded that "long-term maintenance of CRP in San Juan County will result in achieving habitat conditions that are more desirable for Gunnison sage-grouse. Future livestock management practices in areas used by Gunnison sage-grouse should incorporate short-term, high-intensity deferred-grazing rotations."
Management Research Needs: Further research is needed to determine the long-term impacts of emergency Conservation Reserve Program grazing on Gunnison sage-grouse habitat, behavior, and population viability.(Lupis 2005).
Needs: Gunnison Sage-grouse Rangewide Steering Committe (2005) recommended protecting 90% of all habitats currently occupied, or that become occupied through future expansion, through some combination of voluntary agreements, land use planning, easements, fee-title acquisition or land trades.
Use of Fire in Population Management
Use of prescribed fire as a management tool for sage-grouse habitat is controversial [21,27,34,130]. Specific concerns relate to sagebrush removal as a means to manage for a sagebrush obligate and the unknown long-term sagebrush re-establishment rates . A major danger in using prescribed fire for management of sage-grouse habitat is increasing fire frequency beyond the rate at which the sagebrush component of the ecosystem can recover. If fire return intervals become frequent enough to exceed the capacity of sagebrush to repopulate, sagebrush cover would be reduced far below historical levels which could be very detrimental to sage-grouse . Matisse  suggests wildfire and prescribed burns have had a detrimental effect on quality and quantity of sage-grouse habitat.
Miller and Eddleman  acknowledge the debate on benefits of fire to enhance sage-grouse habitat. They state 4 factors determine negative or positive outcome of fire on sage-grouse habitat: 1) site potential, 2) site condition, 3) functional plant group(s) that is(are) limiting, and 4) pattern/size of the burn. Fire is a useful tool to enhance native perennial grass and forbs, particularly in areas where sagebrush is abundant, a "good" population of native forbs is present, and exotic species are limited.
This most often applies to mountain big sagebrush communities where shrub cover can exceed 35% and perennial forbs can increase 2-3 fold following fire . There is little evidence that fire will enhance sage-grouse habitat where there is already a balance of native shrubs and perennial grasses and forbs. Fire should not be used where sagebrush cover is the limiting factor for sage-grouse or where the understory lacks perennial forbs and grasses and introduced annuals are present.
Response of native understory species to fire is usually determined by moisture spectrum and condition of the site. On mesic sites, fire is useful for increasing amounts, nutrient quality, and season of succulence of perennial grasses and annual forbs important in sage-grouse diet. However, in the drier sagebrush cover types, perennial forbs are not increased by fire.
Fire can open up dense stands of sagebrush and increase landscape level heterogeneity, or homogenize large landscapes by removing the shrub layer and promoting dominance of introduced annuals. Blaisdell and others  state primary use of fire on sagebrush-grass ranges should be to control dense stands of sagebrush so more desirable species can increase. The goal should be roughly consistent with the climax cover that can be attained in a particular habitat type or site. In addition, they state grazing management after burning is essential. Most burns should be completely protected from livestock grazing for at least 1 and possibly 2 growing seasons. Benson and others  recommend a nongrazing period of 2-3 years. On areas where cheatgrass (Bromus tectorum) is abundant, special measures may be necessary to prevent recurrent fires .
Braun and others  provide the following guidelines to be used when altering sagebrush habitat:
1. The state wildlife agency will be notified of each specific proposal to control vegetation a minimum of 2 years in advance of treatment by means of an "Environmental assessment." In situations where it is not possible to provide such notice (i.e. private lands), the state wildlife agency should be notified as soon as the project is proposed. Lead time is necessary to evaluate control projects during all seasons of the year. a.) The public land-management agency will provide the state wildlife agency with maps on which the proposed treatment areas are located along with detailed plans as to the type of treatment and expected results. b.) The state wildlife agency will plot sage-grouse use leks, nesting areas, wintering sites, and meadows and summer range or brooding areas on the maps. c.) Representatives of the cooperating agencies will meet on the proposed project area for an on-the-ground inspection following completion of the maps. d.) No sagebrush will be treated or removed until a comprehensive multiple-use management plan has been completed for the area. e.) Project plans for sagebrush control will include provisions for long-term quantitative measurements of vegetation before and after control to acquire data on the effects on wildlife habitats, and to ascertain whether objectives of the project were accomplished. The land-management agency should bear responsibility for evaluation of the project as it relates to habitat, while the state wildlife agency should assume responsibility of measuring the effects of the project on the sage-grouse resource.
2. No sagebrush control work will be considered where live sagebrush cover is less than 20%, or on steep (20% or more gradient) upper slopes with skeletal soils where big sagebrush is 12 inches (30 cm) or less in height.
3. The breeding complex (leks and nesting areas) will be considered as all lands within a 1.9 mile (3 km) radius of an occupied lek (in some situations, depending on the quality of the nesting habitat, this radius may well exceed 1.9 miles (3 km)). Control of vegetation within the breeding complex will not be undertaken within 1.9 miles (3 km) of leks or on nesting and brood areas. On-site investigations by land-management and state wildlife agency personnel will be essential to determine inviolate areas. Areas to be protected from treatment will be marked on maps.
4. There will be no sagebrush control attempted in any area known to have supported important wintering concentrations of sage-grouse within the preceeding 10 years.
5. No control will be attempted along streams, meadows, or secondary drainages (dry or intermittent). A 109 yard (100 m) strip (minimum) of living sagebrush will be retained on each edge of meadows and drainages. On-site inspections by land-management and wildlife agency personnel will be made to assess the desirability of increasing or decreasing the width of untreated strips in specific areas.
6. When sagebrush control is found to be unavoidable in sage-grouse range, all treatment measures should be applied in irregular patterns using topography and other ecological considerations to minimize adverse effects to sage-grouse. Widths of untreated areas can vary for the convenience of application technique, except treated areas will not be wider than 33 yards (30 m) and untreated areas will be at least as wide as treated areas. Untreated areas will not be treated until food and cover plants in the treated areas attain comparable composition to the treated areas.
7. Where possible, spraying will be done with a helicopter or ground equipment. No spraying will be done when wind velocity exceeds 6.2 miles per hour (10 km/hr.)
8. Whenever possible, complete kill or removal of sagebrush in treated areas should be avoided. Partial kill or removal of sagebrush may enhance the area for livestock, prevent loss of all snow cover in winter, and allow for some use of the disturbed area by sage-grouse.
Prescribed fire has been used by the U.S. Forest Service on sagebrush lands in the 12-inch (300 mm) or greater precipitation zones. Results have usually been positive in terms of forb response. In the 8- to 12-inch (200-300 mm) precipitation zones, best results seem to occur with April burns when fine fuels from the previous growing season carry a relatively "cool" fire. Small burns in irregular patterns or strips not exceeding 50 yards (45 m) in width and 100 yards (90 m) long are best. Where wildfire is a concern during summer months, burned strips perpendicular to the prevailing summer winds serve as fire breaks .
After a study of sage-grouse use of burned, unburned, and seeded sites, Sime  summarized several factors researchers feel should be considered before using fire to manage for sage-grouse: 1) Radio telemetry rather than observation should be used to insure proper identification of seasonal ranges of specific population segments as some segments may be sedentary while others are migratory . 2) Openings in the overhead canopy should be restricted to 1 to 10 acres (0.4-4.0 ha) . 3) Fire should only be used when desirable vegetation is dormant so as not to harm the plant species grouse rely on for food and/or cover . 4) The burn site should not be grazed until a vigorous stand of self-perpetuating vegetation is well established . Fire would be most effective in areas where annual precipitation enables rapid revegetation and in areas with a limited potential for invasion of the site by weedy, undesirable species. When few propagules from the native vegetation community are available or when fire is used in areas of low precipitation, the disturbed site may require artificial seeding. Seeding crested wheatgrass (Agropyron cristatum) in sage-grouse range is not recommended.
Call and Maser  suggest the following list to consider when using fire to manage sage-grouse habitats:
1) Fire is an inexpensive tool that can be used for habitat manipulation, but all projects must be carefully evaluated, planned, and supervised. A set of clear objectives is essential.
2) Fire is best used in a manner that results in a mosaic pattern of shrubs and open areas, where the resultant openings range in size from 1 to 10 acres (0.4-4.0 ha).
3) Large, severe fires may remove an excessive amount of cover or may sterilize the soil.
4) Burning within an area should be done on a rotational basis, different patches burned every few years, with as long as 20 years between burning treatments on each site. This will produce a variety of habitats within the general area. Timing of treatments over the years will depend on sagebrush response and growth rates at specific sites.
5) Best results from burning occur in late April and early May when dry grasses and other herbaceous fuels from the previous growing season will carry a relatively "cool" fire. This will leave some sagebrush and still create openings for additional growth of grasses. Fires in late spring and early summer, however, could destroy many nesting birds and other young wildlife, including sage-grouse, so use of fire is preferable when young are capable of escaping. At times, it may be necessary to use prescribed fire in the spring to obtain the desired changes in habitat. Strip burns that do not exceed 50 yards (45 m) in width and 100 yards (90 m) in length create desirable openings for sage-grouse .
6) Sagebrush habitats identified as important wintering areas that are still in vigorous condition should remain intact. Sage-grouse depend on sagebrush leaves in such areas, not on potential development of grass and forbs in the understory or interspersed openings. If important stands of sagebrush used by sage-grouse for wintering have deteriorated because of such things as insects, old age, or livestock grazing, the manager should initiate measures to rejuvenate the stand by light chaining, by reduced grazing, or other means.
7) Four primary elements needed for a successful burn in areas with more than 11.8 inches (300 mm) of precipitation are (1) wet soil; (2) windspeed in excess of 8 mph (12.8 km/hr) and gusty; (3) fine fuels of 612-704 pounds/acre (278-320 kg/ha); and 4) no burning after spring grass growth reaches 2 inches (5 cm) unless burning is to improve the forbs in the community. Prescribed burns should be conducted when plants preferred as food by sage-grouse are dormant .
8) Livestock concentrate on burned areas and eat the new growth, so they need to be carefully managed. Haphazard burning and heavy grazing accelerate sagebrush reinvasion, soil erosion, and loss of forage plants desirable for both grouse and livestock. Grazing use must therefore be regulated to prevent excessive reinvasion by sagebrush (more than 10,000/acre (24,700/ha)) and to prevent removal of more than 50% of the annual herbaceous growth (by weight).
9) Sagebrush taxa and their value to grouse need to be identified prior to burning. Some subspecies, such as mountain big sagebrush, may invade an area immediately after burning and may not be as desirable for sage-grouse as the original species or subspecies .
Breeding: Regardless of the method used to reduce or eliminate sagebrush cover in sage-grouse breeding habitat, control actions have the potential for reducing breeding populations of sage-grouse. Moreover, sagebrush reduction programs may exacerbate the negative effects of natural phenomena such as drought, causing extreme declines in the sage-grouse populations . Martin  found 80% of all cock sage-grouse and over 80% of all hen locations were in sagebrush stands with canopy cover exceeding 20%. He comments this is also the range of sagebrush canopy cover where control is most likely to occur.
Before making any alterations of sagebrush habitat in the vicinity of leks, Ellis and others  recommend the following: 1) When possible, protect all sagebrush within 1.86 miles (3 km) radius of a lek as suggested by Braun and others . 2) If alteration is unavoidable within 1.86 miles (3 km) of a lek, identify day-use areas. Once the core-use area has been identified, protect it and try to provide a buffer zone around it if possible. Because sage-grouse often walk to day-use areas, it is recommended that a continuous strip (i.e. travel lane) no less than 656 feet (200 m) be maintained between the lek and the day-use areas. 3) If day-use areas are identified and it is concluded that they cannot be protected, the manager should determine their physical sagebrush characteristics. Preservation of statistically similar adjacent stands along with an adjoining travel lane may provide male grouse with necessary habitat to continue using the lek. Any planned alterations should be done after males have moved to summer or fall ranges. Wallestad and Pyrah  suggest a 2-mile (3.2 km) buffer zone around a lek should be protected from all sagebrush eradication if the manager has not identified the wintering-nesting complexes associated with it.
A fire in the right place at the right time, and of the correct size and intensity can create an opening that can be used as a lek. Such openings, 1 to 10 acres (0.4-4 ha) in size and at the elevations used for breeding, may be beneficial to sage-grouse in homogeneous sagebrush habitats .
Nesting: Sage-grouse prefer light to moderate sagebrush densities for nesting. Where sagebrush is dense (in excess of 20-40% canopy cover) and greater than 2 feet (61 cm) in height, controlled burning to create a mosaic of sagebrush and grassland with a variety of sagebrush heights would probably be beneficial to the birds. Repeated burning could be adverse in this case, as would large "hot" fires that remove an excessive amount of cover [24,72]. Where cover is all ready limited, fires could cause adverse conditions for the birds [59,72].
The U.S. Fish and Wildlife Service currently uses fire as a management tool to improve sage-grouse nesting and brood-rearing habitat at the Hart Mountain National Antelope Refuge (HMNAR) in Oregon . To evaluate recovery of burned vegetation with respect to sage-grouse nesting and brood-rearing requirements, Nelle and others  recommend that scheduling when a habitat is burned should not be predetermined by the length of time since the area last burned. By measuring 3 variables (sagebrush height, percent sagebrush canopy cover, and percent total shrub cover) at permanent, randomly located transects within burned vegetation, a fast and efficient monitoring program to follow the recovery of vegetation could be implemented.
Also on the HMNAR, DeLong and others  studied nesting habitat in relation to predation. They suggest prescribed fire would reduce shrub cover and may increase herbaceous cover. Sagebrush reduction, however may negatively affect sage-grouse nesting habitat in the short term , and should only be implemented in areas where other suitable nesting habitat exists nearby. In the long term, once sagebrush re-establishes in treatment areas, sage-grouse nesting habitat may be enhanced by an improved balance of shrub and grass components available to sage-grouse. They recommend land management practices that increase cover and height of native grasses in sagebrush communities with medium-height shrubs as a means to enhance sage-grouse nesting success and productivity .
Pyle and Crawford  report increased production of forbs and perennial grasses following fire in sagebrush. Increases in perennial grass cover should improve nesting habitat by providing hens with more cover from predators. Greater forb availability should provide hens with more opportunities to meet their physiological demands for nesting and renesting. Burning may be used to increase herbaceous cover or decrease shrub cover but the shrub component is critical to a sagebrush obligate such as sage-grouse . Frequent burns that promote invasion by exotics such as cheatgrass or large burns that remove the sagebrush overstory may not be used by nesting or brood-rearing sage-grouse until sagebrush becomes re-established [30,71]. Managers must consider size of burns, juxtaposition of habitat components, and frequency of burns if they want to improve habitat while still maintaining all components needed by sage-grouse year round .
Burning to remove sagebrush on the Upper Snake River Plain is not justifiable as a sage-grouse management practice because only unburned vegetation in the area offers suitable nesting habitat. No brush control work should occur where live sagebrush cover is less than 20%  as it is on the Upper Snake River Plain. From 1980 to 1996, 28,840 acres (11,676 ha) were burned by prescribed fire on the Upper Snake River Plain, which accounted for 29% of the study area, none of which was suitable nesting habitat in 2000 . Connelly and others  found no evidence that nest success, and thus nest habitat, increased in the treatment area after a prescribed burn on the Upper Snake River Plain and recommend that prescribed burns be avoided in relatively xeric habitats used by wintering and breeding sage-grouse. During drought periods, they recommend prescribed burns be totally prohibited in these habitats.
Brood rearing: Prescribed burning may have different long-term effects as species diversity of vegetation and invertebrate food resources change with succession  and could result in suboptimal nesting and brood-rearing habitat. The cumulative effect of burning upon critical nesting and brood-rearing habitats could be seriously detrimental to a sage-grouse population if vegetation over a large area remains in suboptimal condition for many years. Burn programs should be planned to avoid creating a landscape of adjacent young burns, especially of burns younger than 14 years. Inherent variation in vegetation responses to burning can render predicting the long-term effects of fire difficult .
Spot burns in which several patches of a few acres are burned can produce suitable brood-rearing areas. Spot burns along the edges of meadows where sagebrush is encroaching may also enhance brood-rearing areas, although care should be taken to leave an adequate sagebrush-meadow ecotone to provide necessary cover for sage-grouse. Spring burns during the nesting period must be avoided, but late fall burns may be an alternative where brood-rearing habitats are needed. Burning should seldom be allowed on areas where nesting habitat is limited . Wrobleski  states increases in percent of annual forb production in burned areas will likely provide a rich forage base for prelaying females and young chicks. Abundant food forbs in close proximity to unburned sagebrush cover could benefit sage-grouse broods by providing additional food with adequate cover. In a study in Idaho, Martin  found burning improved habitat for sage-grouse broods. During both postburn years of his study, forb crown cover was significantly higher in burned habitats than in unburned habitats.
Klebenow  states broods seek out areas where their favorite food forbs are abundant. He states most sites like this have been depleted by excessive grazing and require rejuvenation, and fire can be an important part of management to improve these lands. Burning small areas to achieve a mosaic of food and cover areas should produce a pattern most suitable for sage-grouse. Different stages of successional growth would be desirable in order to produce the greatest variety of food forb items. Burning should probably be done on a rotational basis, burning different patches each year or every few years, possibly with as long as 20 years between burning treatments on each site. A diversity of habitat types, in terms of both food and cover, should be an objective for this habitat. Using fire to open dense sagebrush canopies in occupied sage-grouse range may enhance brood-rearing areas by increasing forb production according to Sime . She also suggests prescribed burning could be used to mitigate for spring/summer habitat lost to agricultural, industrial, or human development and would benefit both sexes and all ages of a sage-grouse population.
Miller and Eddleman  have compiled the following information from various authors on the relative response of forbs common to the sagebrush biome and used as food by sage-grouse:
(S = severely damaged, O = 0 to slight damage, U = undamaged, + = increases, - = declines).
|tapertip onion (Allium accuminata)||U|
|Antennaria spp. (mat spp.)||S|
|Pursh's milk-vetch (Astragalus purshii)||O|
|parsnipflower buckwheat (Eriogonum hieracleoides)||S|
|prickly lettuce (Lactuca serriola)||O-U|
|slender phlox (Microsteris gracilis)||U|
|spiny phlox (Phlox hoodii)||S|
|lambstongue groundsel (Senecio intergerrimus)||O|
|yellow salsify (Tragopogon dubius)||O|
|largehead clover (Trifolium macrocephalum)||U|
The mountain big sagebrush/antelope bitterbrush habitat type is a key brood-rearing habitat of sage-grouse [71,76]. Fall and spring prescribed fire in dense sagebrush-bitterbrush stands did not adversely influence most primary insects and forbs available on burned sites. Indeed, the food supply on burned sites was enhanced based on the increased frequency of dandelion taxa, total forb cover, total forb diversity, and habitat heterogeneity. However, sage-grouse broods require sagebrush for cover on a daily basis , so burning or other practices conducted in montane settings could reduce foraging habitat if an interspersion of treated and untreated sites is not maintained . Pyle and Crawford  also found that fall burning increased frequency of dandelion taxa on HMNAR, but apparently had no effect on other primary foods after a study of prescribed burning from 1987 to 1989. June and darkling beetles, primary foods of sage-grouse chicks, were unaffected by prescribed fire. Total forb cover ranged from 13 to 15% on burned plots to 8% on unburned controls during the 2nd growing season. The same prescribed fire reduced total shrub cover from 1987 to 1989. Authors stated fall-burned sites were perhaps most suitable to broods because they supported the greatest amount of dandelion taxa. However, the prescribed fire reduced sagebrush cover which diminished its site value as a food and cover source for broods. Brood cover was changed but not eliminated by prescribed fire. Cover was altered from dominance by shrubs before burning to dominance by forbs, grasses, and sprouting shrubs after burning.
Wrobleski  studied greater sage-grouse brood-rearing habitat on the HMNAR in Oregon. He compared burned and unburned plots and found:
1. (Morphological) Reproductive effort by individual plants of at least 5 species was greater in 1st-year burned areas, indicating that fire-enhanced flowering occurred in some of the herbaceous dicot species used by sage-grouse. This increased response was observed in both annual (Phlox spp.) and perennials (Lomatium spp., Modoc hawksbeard, shaggy milkvetch, and longleaf phlox).
2. (Phenological) There was a longer period of active photosynthesis observed in all selected species in burned plots.
3. (Arthropod abundance) Populations of arthropods appear to be able to maintain themselves through disturbance by fire.
Greater numbers of inflorescences and flowers provide prenesting hens and broods with increased quantities of higher quality foods. By extending the period of potential photosynthesis and plant succulence on these herbaceous dicot species, forage quality will be higher later into the dry season .
Connelly and others  warn against using fire in relatively low precipitation areas dominated by Wyoming big sagebrush to improve brood-rearing habitat for migratory greater sage-grouse. A study by Fischer and others  indicated the short-term effects of prescribed fire in a xeric (less than 10 inches (250 mm) of annual precipitation) environment did not enhance brood-rearing habitat and may have been detrimental to grasshoppers, which are important in sage-grouse diets. Abundance of grasshoppers was significantly lower in burned habitat the 2nd (P=0.003) and 3rd (P=0.0001) postburn years.
Summer: In a study by Connelly and others  on migratory greater sage-grouse in a xeric region of Idaho, fire apparently did not improve or create summer habitat adjacent to the breeding range. Continuation of long distance movements from the breeding area to summer range up to 4 years after the fire appears to confirm this.
Winter: Any proposed type conversion which includes winter-use areas must be carefully considered. Approval should not be given prior to an on-the-ground inspection of sage-grouse winter distribution during peak snow conditions. What may appear to be an excessive amount of sagebrush during summer months may provide only minimal amounts available above the snow for wintering birds. Burning should seldom be allowed on winter use areas and reseeding may be needed in xeric zones . Critical winter habitats are very vulnerable to treatment since big sagebrush control has traditionally been directed towards dense stands on flat to gentle slopes [45,103]. Braun and others  state quality of sage-grouse wintering habitat after sagebrush removal treatments is directly related to the amount of sagebrush remaining. In light of the number of months of use by sage-grouse and the potentially large area that a winter range may influence, removal of sagebrush from these segments would greatly reduce sage-grouse populations over large areas . Loss of sagebrush on a relatively small area, but a relatively large portion of wintering habitat, was followed by a large decline in sage-grouse numbers in Montana . Beck  states disturbance of sage-grouse winter habitat in identified winter-use areas should be avoided or kept to a minimum.
Connelly and others  suggest that in some instances, especially where the herbaceous understory is badly depleted or junipers (Juniperus spp.) have invaded, fire may be used to improve the ecological condition of a site. If fire is used in this manner, treatment should be designed to preserve sage-grouse winter habitat and allow rapid recolonization of the burned area by sagebrush.
Robertson  studied the effects of an August, 1989, prescribed burn on the winter ecology of migratory greater sage-grouse in southeastern Idaho. Before the prescribed fire, greater sage-grouse were located on the proposed treatment area 42% (1988) and 34% (1989) of the time. Following the fire in fall of 1989, only 6% of greater sage-grouse locations were found within the burned area. The prescribed burning of winter range probably caused this change in distribution. The mosaic effect of the vegetation created by the burn should still maintain stands of adequate habitat within the burn, but other factors such as inability to occupy snow roosts, theremoregulatory stress, and intraspecific competition, might preclude the use of these areas as suitable cover. Burning did not appear to adversely influence greater sage-grouse on the study area except for redistributing them. If adequate habitat is not available within 6.21 miles (10 km) (the limit of movements from leks of capture during the study) sage-grouse may suffer higher rates of predation and/or starvation, or sage-grouse may emigrate to areas where habitat is more readily available. Moreover, even if critical wintering habitat is not lost in a fire, loss of habitat required during the breeding/brood-rearing season is possible. The guideline for protecting habitat within 1.86 miles (3 km) of a lek  may not provide adequate protection of winter range for a migratory population, because sage-grouse were located over twice that distance from their lek of capture. Since no differentiation on a large scale can be made between winter and spring use areas, sagebrush management should only be initiated when all factors are considered. Any prescribed burning on environments having migratory populations of sage-grouse should be initiated only after critical use areas are identified. Critical wintering areas can be defined as those areas sustaining use by sage-grouse in winters of "above average" snowfall. Habitat may be plentiful in years of average snowfall; however, wintering sage-grouse could be negatively impacted should prescribed burning take place on critical seasonal-use areas.
In another Idaho study conducted in xeric, migratory greater sage-grouse habitat, Connelly and others  determined burning likely has a detrimental effect on greater sage-grouse populations, and areas affected by prescribed burns may burn again because of wildfire. Results of their study do not support use of fire to improve rangelands that provide satisfactory sage-grouse habitat. The authors urge managers to refrain from burning in low precipitation (10.4 inches (< 260 mm)) sagebrush habitats that are used by breeding greater sage-grouse.
For specific information on use of fire in various types of sagebrush habitats, see the Fire Effects section of sagebrush reviews on this website.
Future of the sage-grouse depends largely on people's ability and willingness to maintain habitat vital to its needs. Sage-grouse are habitat-specific to 1 particular plant type in meeting their life requirements. Destruction of habitat has been the basic cause of sage-grouse decrease throughout the West .
Sage-grouse once occurred virtually everywhere there was sagebrush. Sage-grouse have declined primarily because of loss of habitat due to overgrazing, elimination ofsagebrush, and land development . Sage-grouse populations began declining from 1900 to 1915, when livestock utilization of sagebrush rangeland was heavy . In the 1950's and 1960's, land agencies adopted a policy of aggressive sagebrush control to convert sagebrush types to grassland. Chaining, frequent fire, and herbicide treatments reduced sagebrush by several million acres, and sage-grouse numbers plummeted drastically [23,85]. Conversion of sagebrush types to grassland has since been brought into question as a management practice for both wildlife and livestock [65,66,108,124].
Daubenmire  questions removal of sagebrush as a management tactic and lists 6 concerns:
1. There is little evidence to indicate the extent to which the desired grass increase (measured shortly after shrub eradication) is maintained.
2. Protection afforded many grass plants by dense clumps of shrubs is the sole reason why any perennial grass remains on much of the depleted ranges. Sagebrush elimination opens the way to complete destruction of perennial grass by overuse.
3. Studies in Washington  have shown that for more than 4 months in the summer, big sagebrush uses only water that has percolated through the soil profile below the reach of grass roots. Removal of sagebrush allows some minerals to migrate permanently below the reach of grass roots.
4. Removing sagebrush eliminates certain elements of avifauna. While rearing their young, these birds drain insect populations. Increased insects may damage the residual grass.
5. When sagebrush is removed by herbicidal sprays, certain perennial broadleaved forbs are heavily damaged or eliminated.
6. In some areas sagebrush promotes the uniform accumulation of snow and delays its melting.
Call  states:
"Any land use practice which has as its objective the permanent elimination of sagebrush and establishment of grasses in the Mountain West will ultimately reduce the collective carrying capacity of that range for livestock, elk, mule deer, antelope, sage-grouse, and many smaller species of wildlife."
For detailed information on individual species of sagebrush and effects of various control measures on those species, see the summary for each species in FEIS.See Fire Effects and Management for information on fire and sage-grouse.
Relevance to Humans and Ecosystems
Gunnison sage grouse and ranchers depend on the same habitats, which may lead to competition of resources between livestock and sage grouse. However, this is a minor problem, as both ranchers and sage grouse seem to have a mutually beneficial relationship.
Sage grouse and ranchers both depend on the same habitats. If ranching profits decrease, the pressure to sell land increases, which often results in habitat fragmentation. If sustainable yields can be attained from these lands, it can help protect the remaining sage grouse populations. Gunnison sage grouse have diverse seasonal habitat requirements which make them a potential keystone species for other grassland species.
Positive Impacts: ecotourism ; research and education
Comments: Historically, all sage-grouse were classified as a game species and subject to hunting under state wildlife laws. Colorado and Utah have eliminated hunting for sage-grouse in areas occupied by Gunnison sage-grouse.
Stewardship Overview: Gunnison Sage-grouse Rangewide Steering Committee (2005) presented a rangewdie conservation plan, including protection needs, habitat guidelines, and strategies to minimize habitat degradation.
The Gunnison sage-grouse (Centrocercus minimus) is a species of grouse endemic to the United States. It is similar to the closely related greater sage-grouse (Centrocercus urophasianus) in appearance but about a third smaller in size, with much thicker plumes behind the head; it also has a less elaborate courtship dance. It is restricted in range to southwestern Colorado and extreme southeastern Utah, with the largest population residing in the Gunnison Basin region in Colorado. Despite being native to a country where the avifauna generally is relatively well known, it was overlooked until the 1990s due the similarities with the sage grouse, and only described as a new species in 2000—making it the first new avian species to be described from the USA since the 19th century. The description of C. minimus as a separate species is supported by a molecular study of genetic variation, showing that gene flow between the large-bodied and the small-bodied birds is absent.
Gunnison sage-grouse are notable for their elaborate courtship rituals. Each spring males congregate on leks and perform a "strutting display". Groups of females observe these displays and select the most attractive males to mate with. Only a few males do most of the breeding. Males perform on leks for several hours in the early morning and evening during the spring months. Leks are generally open areas adjacent to dense sagebrush stands, and the same lek may be used by grouse for decades.
The numbers of this species are declining due to loss of habitat; their range has shrunk in historical times. Following petitions the species has been proposed for listing under the Endangered Species Act, by the United States Fish and Wildlife Service.
Gunnison sage-grouse occur in seven counties in southwestern Colorado and 1 county in southeastern Utah.
Timing of major life events
Males gather on the lek or strutting grounds, which are small open areas where breeding occurs, in late February to April, as soon as the lek is relatively free of snow. Only a few dominant males, usually 2, breed. After mating, the hen leaves the lek for the nesting grounds. Clutch size ranges from 6 to 8 eggs; incubation time is 25 to 27 days. sage-grouse apparently have high rates of nest desertion and nest predation.
Gunnison sage-grouse are totally dependent on sagebrush-dominated habitats. Sagebrush is a crucial component of their diet year-round, and sage-grouse select sagebrush almost exclusively for cover.
- BirdLife International (2012). "Centrocercus minimus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Young, J.R., C.E. Braun, S.J. Oyler-McCance, J.W. Hupp, & T.W. Quinn (2000). "A new species of sage-grouse (Phasianidae: Centrocercus) from southwestern Colorado". Wilson Bulletin 112 (4): 445–453. doi:10.1676/0043-5643(2000)112[0445:ANSOSG]2.0.CO;2.
- Kahn NW, Braun CE, Young JR, Wood S, Mata DR, Quinn TW (1999). "Molecular analysis of genetic variation among large- and small-bodied Sage Grouse using mitochondrial control region sequences". The Auk 116 (3): 819–824. doi:10.2307/4089344.
- Gunnison Sage-grouse. Western State Colorado University (2013)
- Johnsgard, Paul A. (1973). Grouse and quails of North America. Lincoln, NE: University of Nebraska Press ISBN 0803208103.
Names and Taxonomy
Comments: Gunnison sage-grouse (Centrocercus minimus) formerly was regarded as conspecific with the greater sage-grouse (C. urophasianus). It was recognized as a distinct species by AOU (2000) on the basis of genetic differences (Kahn et al. 1999, Oyler-McCance et al. 1999) and differences in size (Hupp and Braun 1991), courtship behavior (Young et al. 1994), and plumage (Young et al. 2000).
The scientific name for the genus of sage-grouse is Centrocercus.
Within this genus are 2 species: the Gunnison sage-grouse,
Centrocercus minimus Bradbury and Vehrencamp, and the greater sage-grouse,
Centrocercus urophasianus (Bonaparte) . The greater sage-grouse has
2 recognized subspecies: the eastern sage-grouse,
Centrocercus urophasianus ssp. urophasianus, and the western sage-grouse,
Centrocercus urophasianus ssp. phaios Aldrich . Sage-grouse are
members of the family Phasianidae .
In this report "sage-grouse" refers to both greater
sage-grouse and Gunnison sage-grouse. Where the literature refers to a
subspecies of greater sage-grouse or to Gunnison sage-grouse, they will be
identified as such.
There is no evidence that the 2 species of sage-grouse interbreed
, but sage-grouse do rarely hybridize with both sharp-tailed grouse
(Tympanuchus phasianellus) and dusky grouse (Dendragapus obscurus) .
Hybrids of sharp-tailed grouse and greater sage-grouse have been found in
Montana , Saskatchewan , and North Dakota . A hybrid of dusky grouse
and sage-grouse was found in Utah .
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