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).

Source: Wikipedia