Sooty Grouse are large, chicken-like birds with small heads. The males have a long, dark tail tipped in light gray. Their plumage is darker than the Dusky Grouse overall and expose bare yellow throat patches during courtship displays. The females are speckled in brown and black with a dark tail. Juveniles are similar to females. In the Sierra Nevada of California, individuals are paler gray overall than the rest of the population of Sooty Grouse elsewhere. They have a length of 15.8-19.7 inches (40-50 centimeters) and a weight of 26.5-45.9 ounces (750-1300 grams).
Sooty Grouse are residents year-round along the Pacific coast of North America. During breeding season, they can be found in forested habitats from sea level to thousands of feet in elevation. Lowland forest are the preferred habitat for this species. In winter, they are found almost entirely in coniferous forests.
Sooty Grouse eat mainly leaves, flowers and conifer needles. They, especially juveniles, will also eat small invertebrates.
Sooty Grouse almost always nests on the ground with variable amounts of cover. The nest is generally a shallow depression in the ground, lined with dead vegetation and body feathers. At hatching, the hatchlings are downy and able to follow their mother.
Sooty Grouse spend most of its time on the ground foraging, but will also forage for buds in deciduous trees and needles in coniferous trees. During winter, Sooty Grouse spend most of their time in coniferous trees eating needles. In general, males vocalize often and while perched in trees.
The male makes very deep, booming, hooting calls that are hard to tell where they came from. Females make cackles and whinnies.
Sooty Grouse are suffering a small decline in their populations currently.
- The Sooty Grouse is the third largest grouse in North America, and one of the largest in the world. The two sage-grouse are the only larger North American species.
- The number of tail feathers a bird has is usually constant within a species (and usually numbering around 10). The Sooty Grouse, however, can have from 15 to 22.
- Sooty Grouse are called Gallo Fuliginoso in Spanish and Tétras fuligineux in French.