(Science: ornithology) Any of the numerous species of gallinaceous birds of the family Tetraonidae, and subfamily Tetraoninae, inhabiting Europe, asia, and North America. They have plump bodies, strong, well-feathered legs, and usually mottled plumage. The group includes the ptarmigans (Lagopus), having feathered feet.
Among the European species are the red grouse (Lagopus Scoticus) and the hazel grouse (Bonasa betulina). See Capercaidzie, ptarmigan, and heath grouse. Among the most important American species are the ruffed grouse, or new England partridge (Bonasa umbellus); the sharp-tailed grouse (Pediocaetes phasianellus) of the West; the dusky blue, or pine grouse (Dendragapus obscurus) of the rocky Mountains; the canada grouse, or spruce partridge (D. Canadensis). See also prairie hen, and sage cock. The old world sand grouse (Pterocles, etc) belong to a very different family. See Pterocletes, and sand grouse.