grouse \grouse\ grous, n. sing.  pl. prob. after the analogy
   of mouse, mice, fr. the earlier grice, of. griesche meor hen:
   cf. f. piegri`eche shrike. zool.
   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.
   1913 webster

   note: 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.
         1913 webster
see also:
tetraonidae tetraoninae lagopus lagopus scoticus bonasa betulina capercaidzie 
ptarmigan heath grouse bonasa umbellus pediocaetes phasianellus dendragapus obscurus 
d. canadensis prairie hen sage cock pterocles pterocletes 
sand grouse