Grouse

Grouse are a group of birds from the order Galliformes, in the family Phasianidae. Grouse are presently assigned to the tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetraonidae), a classification supported by mitochondrial DNA sequence studies, and applied by the American Ornithologists' Union, ITIS, International Ornithological Congress, and others. Grouse inhabit temperate and subarctic regions of the Northern Hemisphere, from pine forests to moorland and mountainside, from 83°N (rock ptarmigan in northern Greenland) to 28°N (Attwater's prairie chicken in Texas). The turkeys are closely allied with grouse, but they have traditionally been excluded from Tetraonini, often placed in their own tribe, subfamily, or family; certain more modern treatments also exclude them. Later phylogenomic analyses demonstrated conclusively that they are sister to the traditionally defined grouse, and they, along with the somewhat earlier-diverging koklass pheasant, may be treated as grouse (i.e., as basal members of the Tetraonini). This is reflected in some more recent circumscriptions.