THE CHANGES OF PLUMAGE IN RED GROUSE 53 



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

 year. 



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 (PL vi., 

 Figs. 1, 2, 3, 4). 



In September the chin and throat of the cock Grouse contain September, 

 a mixture of many pale autumn feathers much worn and faded, 

 and a few new copper-red ones. Most of the frayed " autumn 

 plumage " feathers are now falling out. The breast and 

 abdomen, wings and tails, are clothed with entirely new winter 

 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. The feathers of the 

 legs and feet of healthy birds are rapidly growing to form thick, 

 white stockings for the winter. Bare legs in September are a 

 sign of belated moult or, in other words, a sign of sickness. 



In October, for the first time since the preceding winter, October, 

 the red and black varieties of Red Grouse become once more 

 conspicuously distinct. This result is due to the new growth 

 of fully pigmented feathers, either red or black, upon the under 

 surface of the body. The upper neck is rapidly becoming 

 copper-red. The chin and throat still show a proportion of 



