PLUMAGE CHANGES OF THE COCK GROUSE 41 



He now rapidly sheds the old feathers of the last winter's plumage which 

 remained throughout the summer upon his breast and abdomen, and replaces 

 them with the exceedingly handsome narrow cross-barred red or brown or 

 blackish feathers of the coming winter plumage. There is no second moult 

 or replacement of these feathers of the breast and abdomen in the cock. Once 

 in the year is enough for this special area, and the feathers that " carry through " 

 are wholly of the winter plumage. Thej^ are often broadly tipped with white. 

 The chin feathers which survived with those of the breast and abdomen 

 are now also replaced by new ones. It is noticeable that in the Ptarmigan 

 it is also the white feathering of the chin and of the breast and belly, as 

 well as of the wings and tail, which is changed once only in the year, 

 exactly as with the winter plumage of the Grouse. It suggests that these 

 two plumages are analogous in each species. 



The plumage changes in the Ptarmigan are, strange to say, quite different 

 to the chancres in the Grouse. The Ptarmigan has three distinct moults and 

 plumages in the year. The Red Grouse has but two. 



In August, as has been said, the cock Red Grouse has begun to put 

 on his winter plumage. The feathers of the breast and abdomen are full 

 of sheaths and sheath-scurf, the growth of these feathers being very rapid 

 and often scarcely noticeable. On the rump, back, and to a less extent on 

 the shoulders, new rich red-brown feathers finely marked with black lines are 

 showing here and there. Primaries, secondaries, tail feathers, and coverts are 

 now replaced by new and blackish feathers with perfect and unbroken outlines. 

 Even a few new rich copper-coloured feathers are appearing as isolated touches 

 of bright colour amongst the faded broad - barred autumn feathers of the 

 upper breast. The feet and legs are bare, save where new white feather 

 tips are just appearing through the skin, and the claws of all the healthy 

 birds are being shed (PI. xiii., Figs. 3, 4, 5, 6). 



In September the chin and throat of the cock Grouse are a mixture of 

 many pale autumn feathers much worn and faded, and a few new g 

 copper-red ones. Most of the frayed "autumn plumage" feathers t'^'^^®'"- 

 are now falling out. The breast and abdomen, wings and tails, are clothed 

 with altogether new feathers, while the head and neck, back, shoulders, rump, 

 and coverts of the tail are in a transition state, the " autumn " feathers 

 frayed and bleached at the tips, contrasting with the new rich chestnut and 

 darker brownish winter feathers with their fine black transverse markings. 



