- 18.1–22 in
- 34.9–85.9 oz
- Larger than a Ring-necked Pheasant; smaller than a Wild Turkey.
- Tétras du Gunnison (French)
- Greater Sage-Grouse has several subspecies, but the Gunnison Sage-Grouse was never one of them; it was always assumed that the two were the same species. It wasn’t until 2000 that the Gunnison Sage-Grouse was recognized as its own species, making it the first new bird species described in the United States since the 19th century. Differences in size, coloring, plume size and shape, display behavior, and genetics indicate that this species is distinct from the Greater Sage-Grouse.
- Sage-grouse have a specialized stomach that digests the tough sage-brush, their main food.
- Over the harsh winter, sage-grouse actually manage to gain weight and strength in preparation for the breeding season by feeding on the leaves of sagebrush. They get water from feeding on snow.
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.
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.
- Clutch Size
- 3–10 eggs
- Number of Broods
- 1 broods
- Egg Length
- 2.1–2.2 in
- Egg Width
- 1.5–1.5 in
- Incubation Period
- 25–29 days
- Nestling Period
- 1 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.
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.
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.
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.
Gunnison Sage-Grouse have declined greatly from presettlement estimates, and just under 5,000 are thought to remain. The species was listed as federally threatened in November 2014. About 85 percent 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. This species is on the 2014 State of the Birds Watch List, which lists species most in danger of extinction without significant conservation action.
- Schroeder, M. A. et al. 1999. Greater Sage-Grouse (Centrocercus urophasianus). In The Birds of North America, No. 425 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
- The State of the Birds Report 2014.
- U.S. Department of the Interior, Fish and Wildlife Service. 2010. Endangered and Threatened Wildlife and Plants; Determination for the Gunnison Sage-grouse as a Threatened or Endangered Species; Proposed Rule. Federal Register 75, no. 187 (September 28, 2014): 59804.
- U.S. Department of the Interior, Fish and Wildlife Service. 2014. Endangered and Threatened Wildlife and Plants; Threatened Status for Gunnison Sage-Grouse; Final Rule. Federal Register 79, no. 224 (November 20, 2014): 69192.
- Young, J. R. et al. 2000. A new species of sage-grouse (Phasianidae: Centrocercus) from southwestern Colorado. Wilson Bulletin 112: 445-453.
Resident (nonmigratory) to short-distance migrant, often moving relatively short distances (20 miles or so) between wintering and nesting areas. Females may lead their chicks to summer feeding areas in higher elevations or wet areas.
Find This Bird
The best way to see Gunnison Sage-Grouse is at a lek site—but be aware that sage-grouse are extremely sensitive to disturbance. Because of this species’ low numbers, only one lek is accessible to the public as of 2015. It’s the Wuanita Lek about 19 miles east of Gunnison, Colorado. Western State Colorado University hosts a page about the lek, its current viewing conditions, and behavior and precautions for lek viewing.