Sage Grouse

"Sage Grouse" is the traditional common name for the large grouse of the western sagebrush sea, historically treated as a single species before ornithologists split it in 2000 into two species: the widespread Greater Sage-Grouse (Centrocercus urophasianus) and the smaller, more range-restricted Gunnison Sage-Grouse (Centrocercus minimus) of southwestern Colorado and adjacent Utah. Both are large, mottled grayish-brown grouse with a long, spiky, pointed tail, a black belly patch, and, in males, a ruff of white breast feathers surrounding inflatable yellow-green air sacs used in an elaborate strutting courtship display.

Sage Grouse are considered an indicator species and umbrella species for the health of the sagebrush ecosystem, since their populations track the extent and quality of intact sagebrush habitat across the Intermountain West.

Key field marks

• Large, mottled gray-brown body with a black belly patch
• Long, spiky, pointed tail feathers
• Males show a white breast ruff and, during display, inflate bright yellow-green air sacs on the chest
• Found only in and near sagebrush habitat

Similar species

Sharp-tailed Grouse overlaps in range but is smaller, paler, lacks the black belly patch, and has a shorter, more pointed central tail without the spiky overall tail shape. Greater and Gunnison Sage-Grouse are best told apart by range and, in males, subtle differences in tail filoplume length and display sounds.

Habitat and Range

Sage Grouse are obligate residents of sagebrush steppe, rarely found far from stands of big sagebrush, which provide both food and cover throughout the year.

Range

Historically found across much of the Intermountain West from southern Canada to California and New Mexico, the species' range has contracted significantly with the loss and fragmentation of sagebrush habitat, though sizable populations persist in Wyoming, Montana, Nevada, Idaho, and other western states.

Migration

Some populations undertake seasonal movements of tens of miles between distinct summer and winter ranges in response to snow depth and forage availability, while others are largely resident.

Behavior

Males gather at traditional communal display grounds called leks each spring, where they compete for the attention of visiting females through elaborate strutting displays.

Voice

During display, males produce a distinctive series of popping and swishing sounds by inflating and releasing air from their esophageal sacs, audible over long distances on quiet mornings.

Feeding

Sagebrush leaves make up the bulk of the diet, especially in winter when little else is available, supplemented by forbs and insects during the breeding season.

Nesting and breeding

Females nest on the ground under sagebrush cover, often at some distance from the lek, and raise the brood alone after mating with a dominant male at the lek.