Sage Grouse

"Sage Grouse" is the traditional name for the large, mottled gray-brown grouse of the sagebrush sea, now formally split into the Greater Sage-Grouse and the smaller, more range-restricted Gunnison Sage-Grouse. Both are heavy-bodied, long-tailed birds with a black belly patch and finely vermiculated gray-brown upperparts that blend seamlessly into sagebrush habitat.

Males are famous for their elaborate breeding display: fanning a spiky, pointed tail while inflating a pair of yellow-green air sacs on the chest, producing a series of odd popping and swishing sounds on communal display grounds called leks.

Key field marks

• Very large, mottled gray-brown body with a black belly
• Long, pointed, spiky tail feathers
• Males: white breast filoplumes, yellow air sacs on chest during display
• Restricted almost entirely to sagebrush habitat

Similar species

• Gunnison Sage-Grouse is smaller, with longer, more filamentous tail plumes and more contrasting white barring; the two species overlap only marginally and were formally split in 2000.
• Sharp-tailed Grouse is much smaller, browner, lacks the black belly patch, and occupies grassland rather than pure sagebrush.

Sage Grouse are obligate sagebrush specialists, depending on large, unbroken tracts of sagebrush steppe across the Great Basin and surrounding intermountain west, from southern Canada through California, Nevada, Utah, Colorado, and the Dakotas. Loss and fragmentation of sagebrush habitat has driven significant population declines.

The species is largely non-migratory to short-distance migratory, with some populations shifting between higher-elevation summer range and lower, wind-scoured winter range where sagebrush remains exposed above snow.

Each spring, male Sage Grouse gather at traditional lek sites at dawn, strutting and inflating their yellow air sacs while fanning the spiky tail, producing a distinctive popping and swishing sound audible from a distance. Females visit leks to select mates, then nest and raise young alone.

Diet shifts seasonally: sagebrush leaves make up the bulk of the winter diet (nearly the only food available), while forbs and insects become important in spring and summer, especially for growing chicks. Nests are shallow ground scrapes under sagebrush cover, with clutches of 6-9 eggs.