40 THE GROUSE IN HEALTH AND IN DISEASE 



shedding the grey ends of the feathers, leaving the blacker parts exposed. 

 This method is common among birds, but the Red Grouse has been credited 

 with changing in situ the colour and pattern of the flank feathers. Now, with 

 still less reason as it seems, the cock bird has been credited by Mr Millais 

 with achieving his summer or breeding plumage " for the most part by repig- 

 mentation and pattern change of most of the winter feathers below the neck." 



This view cannot be upheld physiologically, and there is much to support 

 the contention that the feathers which are believed to effect this change of 

 pattern without moult are actually new growing feathers. This can readily 

 be shown by the demonstration of their unshed sheaths. The misleading 

 birds are again in this case the cocks which have been too sick to shed 

 the previous "autumn plumage," and so are still struggling, with increasing 

 success as the food improves, to produce a " winter plumage," which they 

 should, and would in health, have achieved in October. 



That the cock bird should moult the feathers of the legs and feet between 

 March 30th and June 17th is no longer difficult to understand when the 

 prevalence of Strongylosis is fully grasped. No bird is safe from the 

 nematode infestment, and we are led to think that the majority of cock 

 birds are so badly infested that they are forced to defer the autumn moult 

 which should precede that of the previous winter. It is therefore obvious 

 that between March and June there will be every stage of good or bad 

 leg and foot-feathering between the newly acquired thick, white winter 

 stocking of the sick cock, and the naked featherless clean moulted leg 

 and foot of the really healthy male bird in June. In July, again, the 

 healthy cock bird will be found beginning to produce white feather tips 

 over the legs and feet. 



In July the general appearance of the healthy cock is much lighter in 



colour-tone, and much more broken and mottled in pattern - character than 



that of the same bird in the winter. The claws are in many cases 



now ready to be shed, and the primaries, secondaries, and tail feathers 



are in moult. Some six or eight new clean- grown primaries are often to be 



found in July, and the long tail coverts are broad-barred buff and black. 



In August the cock Grouse has, of course, the appearance of full summer 

 or autumn plumage, but it requires very little examination to see 

 that he has already begun to put on feathers of the winter plumage. 



1 " Natural History of British Game Birds," p. 40. 



