Gunnison Sage-Grouse have a very restricted distribution on the sagebrush steppe of western North America and are usually found at elevations of 7,000 feet or higher. They use several types of sagebrush habitat at different times of the year, as well as areas with native grasses and forbs, and riparian habitats. They generally select moist sites for foraging when available. In the winter, at elevations of 5,900–9,000 feet, they stick to locations with substantial cover of big sagebrush, black sagebrush, and low sagebrush and use areas with deciduous shrubs such as Gambel oak, serviceberry, snowberry, and antelope bitterbrush, as well as areas invaded by pinyon and juniper. They usually nest in areas with relatively dense cover from big sagebrush (Artemisia tridentata), although they also use areas with rabbitbrush, greasewood, and grassy areas. Leks are located in clear areas such as broad ridgetops, grassy swales, dry lakebeds, and sometimes recently burned areas. Adult hens lead their growing chicks to areas with good forage, including irrigated pastures, wet meadows, and alfalfa fields, in addition to sagebrush.Back to top
Gunnison Sage-Grouse eat leaves, buds, flowers, forbs, and insects (beetles, grasshoppers, and ants). Leaves (primarily of sagebrush) dominate the diet throughout most of the year and are the principal food from November into April. Forbs and insects are the main food for young chicks, which cannot digest sagebrush for several weeks after hatching. Dandelions and other forbs are important for females as they prepare for laying. In fragmented habitats, Gunnison Sage-Grouse forage and roost in cultivated fields of alfalfa, wheat, and beans.Back to top
Females do all the nest-building, incubation, and raising of the chicks without any help from males. They place their nests on the ground, usually in the shade under a sagebrush shrub and sometimes under tufts of grass within dense patches of shrubs.
Females make bowl-shaped nests scraped into the soft soil and lined with leaves, grasses and forbs, small twigs, and feathers that the female plucks from her breast. The cup interior is about 8–9 inches across and averages 2 inches deep.
|Clutch Size:||3-10 eggs|
|Egg Length:||2.1-2.2 in (5.4-5.6 cm)|
|Egg Width:||1.5-1.5 in (3.7-3.9 cm)|
|Incubation Period:||25-29 days|
|Egg Description:||Variable shades of olive-buff to pale greenish, with fine, darker markings.|
|Condition at Hatching:||The downy, well-camouflaged chicks are precocial, able to feed themselves within minutes of hatching. Typically able to fly weakly after 10 days, and strongly after about 5 weeks.|
Gunnison Sage-Grouse (along with their more widespread relative the Greater Sage-Grouse) offer one of the best examples of the breeding system known as lekking. Males gather by the dozens, or even hundreds, in an opening in the sage to perform complex, highly choreographed courtship displays. Females visit these leks to size up the displays and choose their mates—typically all the females mate with just a few of the males at the lek. This puts intense pressure on males’ displaying abilities if they are to have any chance of passing along their genes. After mating, males have no further contact with the female or the young. Back to top
Gunnison Sage-Grouse has declined greatly from presettlement estimates. Partners in Flight estimates a global breeding population of only 4,600 birds, with 100% living in the U.S. The species rates a 20 out of 20 on the Continental Concern Score, and is both a Tri-National Concern species, and a U.S.-Canada Stewardship species. Gunnison Sage-Grouse was listed as federally threatened in November 2014, and is on the 2016 State of North America's Birds' Watch List, which includes bird species that are most at risk of extinction without significant conservation actions to reverse declines and reduce threats. The species is also listed as Endangered on the IUCN Red List of Threatened Species. About 85% of the species are part of a single population in the Gunnison Basin; the remainder are distributed among six other populations in western Colorado and adjacent Utah. According to the listing decision, the main threats to the species are habitat decline from human disturbance, small population size and structure, drought, climate change, and disease. Specific threats include certain ecologically harmful grazing practices, fences, invasive plants, changes to fire regimes, encroachment of pinyon and juniper on sage lands, extraction of natural resources, water development, and disturbance from recreation.Back to top
Interior, U.S. Department of. (2010). Endangered and threatened wildlife and plants: Determination for the Gunnison Sage-Grouse as a threatened or endangered species. Federal Register 75 (187):59804-59863.
Interior, U.S. Department of. (2014). Endangered and threatened wildlife and plants; Threatened status for Gunnison Sage-Grouse: Final Rule. Federal Register 79 (224):69192-69310.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, USA.
Young, J. R., C. E. Braun, S. J. Oyler-McCance, J. W. Hupp and T. W. Quinn. (2000). A new species of Sage-Grouse (Phasianidae: Centrocercus) from southwestern Colorado. Wilson Bulletin 112 (4):445-453.