Grouse are a member of the order of Galliforms (megapods, turkeys, pheasants, quail, jungle fowl, peafowl, guinea fowl, grouse and ptarmigan). Galliforms all share similiar traits for example they have fowl like beaks, they have four toes (the hind toe is raised) and they are ground nesting.
Grouse and ptarmigan share other characteristics that put them into a small family group (approx 18 species) Tetraonidae. They all have feathered nostrils and feathered legs, Ptarmigan have feathered toes in the winter. Most have red fleshy combs above their eyes, in the male of the species these become enlarged during courtship. Most male grouse also have large air sacs either feathered or coloured at the sides or front of their neck which inflate during elaborate courtship displays (vocal calls, tail fanning, dancing, strutting etc).
Grouse and Ptarmigan can be found across most of the Northern hemisphere, their habitat ranges from boreal coniferous forests, tundra, heather, moorland to grass prairies.