THE GROUSE SUBFAMILY 23 



exhibited at any rate in the case of the blackcock ; for this bird, be 

 it noted, for a short space annually exchanges the brilliant metallic 

 blue of the head and neck for the similar dull hues of the female. 

 Just, in short, as the head and neck are the last to lose the down 

 feathers, so also they are the last to lose the earlier, ancestral, brown 

 livery, which elsewhere on the body has become eliminated. These 

 brown feathers are worn during the months of July and August, 

 when the heavy and trying autumn moult is taking place. At this 

 time flight, save for a few yards, is impossible, for a large proportion 

 of the wing quills are then shed, and the tail feathers have dropped 

 completely; so that the brown-barred coloration of the head and 

 neck possibly form a protective mask. But apart from the " useful- 

 ness" of this peculiar colour change of the head and neck, there 

 can be no doubt about the relations it bears to the more complete 

 " eclipse " plumage of the mallard. 



Thus the resplendent plumage, in the case of both species, 

 answers to the " nuptial " dress of, say the knot, the ruff, or the 

 dunlin. But in the three last-named species, it is to be remarked, 

 the nuptial dress is assumed by a spring and not an autumn moult, 

 as in the case of the Grouse family, wherein it would seem the 

 resplendent dress developed what we may call a precocious tendency, 

 changing the time of its appearance from late to early spring, and 

 from early spring to late winter, and thence back to late autumn. A 

 link in the chain of evidence seems to be furnished by the male red- 

 grouse. This species, like the mallard, breeds in the dress assumed 

 at the autumn moult. In June, after the trying period of courtship 

 is over, he puts on a conspicuously different livery, answering to 

 the " eclipse " dress of the mallard, which is discarded at the autumn 

 moult for the dress which is to serve as the breeding dress. That 

 this plumage, assumed in June the plumage which Mr. Ogilvie-Grant 

 has called the " autumn " plumage answers to the so-called " eclipse " 

 plumage of the ducks is, I believe, unquestionable, though it differs 

 less markedly from the dress which is to be the breeding dress 



