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 or the family Tetraonidae), a classification supported by mitochondrial DNA sequence studies, and applied by the AviList, International Ornithological Congress, the American Ornithologists' Union, and others. 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. Grouse inhabit temperate and subarctic regions of the Northern Hemisphere, from arctic tundra to pine forests to moorland and mountainsides, from 83°N (the rock ptarmigan in northern Greenland) to 28°N (Attwater's prairie-chicken in Texas), or to 16°30'N when the turkeys (ocellated turkey in Belize) are included.