GROUSE AND PTARMIGAN. 399 
o 
The next group of grouse we have to notice are the black-game, 
which have the legs covered with feathers, but the feet naked, and 
the sides of the toes furnished with horny comb-like appendages. Only two species 
are known, the black grouse (Lyrurus tetrix) of Europe and Asia, and the Caucasian 
black grouse (L. mlokostewiczt). The two sexes are commonly known as black- 
cock and grey hen; and the males are distinguished by their general black plumage, 
the peculiar shape of their tail, the outer feathers of which are elongate and curved 
outwards at the extremity. In the blackeock the under tail-coverts are white, 
while in the bird from the Caucasus these parts are black, like the rest of the 
Black-Game. 





WILLOW-GROUSE IN WINTER DRESS, 
plumage. The two species also differ in their changes of plumage; in the former, 
the young male assuming the black feathers of the adult more or less completely 
by the first winter, while in the young male of the Caucasian bird a female-like 
plumage is retained throughout the first winter and spring. During the autumn 
moult, when the males are rarely met with, the black plumage of the head and 
neck is replaced by brownish buff and black feathers, barred like those of the 
female. No doubt this temporary change is protective, enabling the blackcock to 
escape observation, when, owing to the heavy moult in their wings and tail they 
are rendered almost incapable of flight. Black-game are polygamous, one male 
pairing with a number of females, each of which undertakes the entire responsi- 
