Birds. 



8001. 



On the Change of Plumage in the Crossbills and Pine Grosbeak. — Even now it 

 appears that it is not quite clear what is the true mature plumage of these birds, aud 

 as little seems to be known with any certainty at what ages the change (in the males) 

 from bright red to dull red and from dull red to yellow-green, takes place, and as I 

 have lately turned my attention to this subject, and have had good opportunities of 

 obtaining the old birds in every state of plumage, a few observations may not be un- 

 interesting. Keferring to every British authority that I can find, I am led to suppose 

 that the mature plumage in both species is red, in extreme age tinged with yellow; 

 and every coloured figure that I have seen, both of the old male crossbill and pine 

 grosbeak, favours this supposition. But such is not the case : the red plumage is only 

 an intermediate stage, and the full mature dress in the male of both species is bright 

 yellow-green. This is contrary to the opinion of many naturalists ; but I can prove it 

 from many specimens.. I am, however, pretty confident that none of us know for cer- 

 tain how long the birds wear this red livery, or at) what age they assume the mature 

 yellow-green dress. That the red plumage in both species lasts for more than two 

 years, gradually passing from deep carmine to brickdust-red, I feel pretty confident. 

 We may, therefore, describe the change of plumage in the male bird thus: — First, the 

 nest plumage ; dark brown, edged with yellow-green, especially on the head and rump, 

 and this seems gradually to change, even before the first autumnal moult. After the 

 first moult, carmine-red (and in this plumage the bird can breed) ; this colour gra- 

 dually becomes, by moult and wearing, dull brickdust-red, and eventually yellow-green. 

 I have been lucky enough to see specimens both of the pine grosbeak and crossbill in 

 the mature yellow plumage ; but that they are rare may be inferred from the fact that 

 I never, among all the nests of the crossbill that I have taken, have found more than 

 one belonging to a mature male, although I have occasionally shot the old yellow 

 males in the winter in company with the young red birds. In April, 18b'0, I took a 

 nest of the parrot crossbill with three eggs, the largest I ever saw and the finest 

 coloured, evidently from a very old bird. The plumage of this male was bright yellow- 

 green all over, most vivid on the rump and head, but without the slightest shade of red ; 

 the female of the usual gray-green, tinged on the rump with yellow. I can, however, 

 hardly agree with Nilsson that they assume this mature dress at the third moult, else 

 why should we see so few of these yellow-green males in propoition to the red birds? 

 I have never yet seen more than two examples of the mature green pine grosbeak : one 

 was this last winter, in a cage, where he had been confined ten years; he was a red 

 bird when he was caught in the winter, but in the ensuing autumn he changed to 

 bright yellow-green, and since then has undergone little or no change in his plumage: 

 the other was shot in a wild state in Calmar Land, here, in February, 1855 ; 1 have 

 the skin now before me, and it is precisely the same as the specimen I saw in the 

 cage ; his plumage very much resembles that of the female, but the head and rump 

 are much brighter, and the breast and belly much yellower. There appears to be a 

 more marked difference between these old yellow males and the green females in the 

 crossbills than in the pine grosbeak. 1 never yet have had the luck to fall in with the 

 pine grosbeak in breeding dress (and this is the only season when we can come to 

 any safe conclusion). Again, with regard to the pine grosbeak, there is, I think 

 another mystery wants clearing up. I never till this winter had much opportunity 

 of studying this bird in a state of nature. It is true that every winter we have a few 

 in our midland forests, but this winter they have been unusually numerous, and about 

 forty specimens have passed through my hands. In the crossbills I observed that the 

 VOL. XX. 2 A 



