COMMON PTARMIGAN. 427 



or here and there in the immediate vicinity of where he is standing. 

 Ptarmigan appear to be subject to the same disease as Red Grouse; 

 but it is not nearly so widely spread nor so disastrous in its results, pro- 

 bably because the Ptarmigan is not so highly protected or its natural 

 enemies destroyed to such a great extent. 



The Ptarmigan in winter plumage is pure white,, with the exception of the 

 tail-feathers, which are black with narrow white tips. The male ~has also 

 the lores and a stripe behind the eye black. Bill and claws blackish brown ; 

 irides hazel ; above the eye there is a dull scarlet wattle, which increases 

 in size and brilliancy during spring. The white plumage of the wings, 

 outer wing-coverts, lower breast, belly, and the under tail-coverts is for 

 the most part retained until it is renewed in autumn, though many of the 

 white feathers of the underparts are often replaced in summer by coloured 

 feathers. The rest of the plumage appears to be gradually moulted twice 

 before the final autumn moult, the spring feathers being generally nearly 

 black, with huffish-brown vermiculations, and those of autumn pale grey 

 with black vermiculations. The change of feathers proceeds so slowly 

 that the summer moult begins before the spring moult is complete, so that 

 it is impossible to obtain a bird in full spring or summer plumage. The 

 female retains the white on the quills and outermost wing-coverts only, 

 the ground-colour of all the rest of the feathers, except that of the tail, 

 being buff, transversely barred with semi-confluent black bands, and tipped 

 with nearly white, a plumage which appears to be retained until the 

 autumn moult. In birds of the year, after their first spring moult "*, the 

 small feathers are very much vermiculated with buffish brown ; but the 

 black becomes more and more predominant every year, until in very old 

 birds the buffish brown almost disappears from the back and breast. In 

 winter the toes are protected with thick feathers reaching halfway down 

 the claws ; but in summer the fore half of the toes is almost bare. Young 

 in down are very similar to those of the Red Grouse. 



* It is not certain that the spring plumage is obtained by a moult. It is possible that 

 the white feathers gradually change colour in spring, only those being moulted which, by 

 acident during winter, have been so injured that they have lost the power of changing 

 colour. Willow-Grouse kept in confinement are said to change from the white winter 

 dress into the brown summer dress without moulting more than ten per cent, of their 

 feathers ; and early spring examples of this species show white feathers with brown bases, 

 and brown feathers with white tips, apparently proving that the change of colour begins 

 at the base of the feather. 



