The Gunnison Grouse (Centrocercus minimus), also known as the Gunnison Sage-Grouse, is a medium-sized, endangered grouse endemic to the sagebrush ecosystems of the Gunnison Basin in southwestern Colorado and adjacent southeastern Utah. Males are distinguished by white breasts, yellow air sacs, and black bellies, while females are smaller and gray-brown. The species relies on sagebrush and riparian habitats for feeding and cover, and is listed as Endangered (EN) in the AviList v2026 taxonomy.
Learn to identify
Adult male Gunnison Grouse in snow, photographed in Colorado.
Learning lesson · openly licensed photographs, labelled by BirdBot; labels checked against the cited sources and approved by AI
A smaller cousin of the Greater Sage-Grouse. Thick plumes behind the head: longer and thicker than on Greater Sage-Grouse. Pale bars on the tail: more obvious than on Greater Sage-Grouse. Long, pointed tail: spiky, wedge-shaped tail feathers. Best told from Greater Sage-Grouse by range: SW Colorado and SE Utah. Males are slightly larger; female marks are not shown here.
Males are slightly larger; female marks are not shown here.
Sources: Audubon Guide to North American Birds: Gunnison Sage-Grouse · Wikipedia: Gunnison sage-grouse (revision 1363751706)
Photo: Larry Lamsa, CC BY 2.0, via Wikimedia Commons; labels added by BirdBot.
Gunnison Grouse exhibit strong sexual dimorphism, making it relatively straightforward to distinguish adults in the field once you know what to look for. Males are larger and more colorful, featuring white breasts with two round yellow air sacs (cervical apteria) on the chest. These air sacs are covered in scale-like feathers and are inflated during courtship. Males also have a black belly separated from the throat by a white V-shaped area, and spiky brown and white tail feathers that can be fanned out for display.
Females are smaller and lighter, with a cryptic gray-brown coloration that helps them blend into the sagebrush. They lack the prominent air sacs of males and have shorter tail feathers with less plumage. Chicks resemble females but have a brown and white speckled appearance for camouflage.
Compared to their close relative, the Greater Sage-Grouse (Centrocercus urophasianus), Gunnison Grouse are smaller and have longer black filoplumes on their heads. Adult Gunnison Grouse from southwestern Colorado also have shorter and narrower beaks than those from northern Colorado. Typical measurements for the species include a length of 32 to 51 cm and a mass of 990 to 2,435 g.
The Gunnison Grouse is an obligate sagebrush (Artemisia) species, meaning it depends on sagebrush for survival. It is found at elevations of 2,200 to 4,300 m. While sagebrush is essential, the species also relies on riparian habitats for feeding and cover, particularly as sagebrush dries out in colder months. The range is restricted to the Gunnison Basin of southwestern Colorado and adjacent southeastern Utah.
Populations vary in their movement patterns. Some are non-migratory with limited movement, while others are one- or two-stage migratory, preferring different habitat conditions for summer, winter, and mating seasons. Mating habitats, known as leks, are typically areas with low vegetative density and high visibility.
Gunnison Grouse are social birds that travel in flocks and spend an estimated 60% of the day foraging. They are considered sedentary but will travel long distances to find food and cover. In winter, flocks are sexually segregated, with males and females roosting separately, sometimes gathering in the sun for warmth. In spring, flocks reunite at leks where males compete for mates.
Lekking is a form of clumped polygyny where multiple males gather on an arena to display for females. Beginning in mid-March through late May, males migrate to lek sites, often returning to the same location each season. Males strut, inflate their air sacs to make popping noises, and fan their tails to attract females. Only a small percentage of males (10-15%) typically succeed in mating. Males are territorial and may chase or fight intruders. Despite their heavy bodies, Gunnison Grouse are capable fliers, reported to reach speeds of up to 78 km/hr (50 mph), which is their primary escape mechanism from danger due to their short legs.
The diet of Gunnison Grouse shifts seasonally and by life stage. In early summer, insects and forbs are essential for chicks, providing protein for growth. As summer progresses, chicks begin foraging on forbs and later add sagebrush to their diet. In fall and winter, adults and chicks consume mainly sagebrush leaves, often foraging in riparian habitats when sagebrush dries out. The species does not have muscular gizzards, making it difficult for them to grind and digest seeds, so seeds are not a significant part of their diet.
Reproduction is a female-driven process; males do not participate in nesting or brood-rearing. Hens search for nesting sites from late March to April, preferring areas with diverse forbs and sagebrush for nutrition and cover. Nesting occurs from mid-April to June, and hens may migrate away from leks to find optimal conditions. Hens lay 6 to 8 eggs, which hatch in 25 to 27 days. Chicks are precocial, weighing about 30 g at birth, and leave the nest immediately to forage in riparian habitats. They become independent at 10 to 12 weeks of age.
The Gunnison Grouse is currently listed as Endangered (EN) in the AviList v2026 taxonomy. Habitat fragmentation, invasive plant species, and low vegetative diversity are the main threats to the population. Conservation efforts involve collaboration between the Colorado Parks and Wildlife, the Colorado Cattlemen's Association, Gunnison County, and the Bureau of Land Management. Historically, the US Fish and Wildlife Service listed the species as "warranted but precluded" under the Endangered Species Act in 2010, a status that highlighted its ecological importance and the need for habitat protection at that time.
Observing Gunnison Grouse requires a commitment to minimizing disturbance, especially during the sensitive lekking season. The best time to see the species is in spring (mid-March to late May) when males are active on leks. Observe from a distance, using binoculars or a spotting scope, and avoid approaching the lek directly. Do not attempt to startle or flush the birds, as this can disrupt mating and increase stress. If you are in the Gunnison Basin, look for open, low-vegetation clearings near riparian corridors, which are typical lek sites. Always follow local regulations and land access rules.
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