276 Peabody, Crossbills of Northeastern Wyoming. [julv 



townward scavenging for the benefit of their young, had picked 

 up the two young crossbills, one after the other, in the probable 

 absence of both parent birds. It is even possible that the youngsters 

 were removed to places of safety by the mother crossbill herself. 



No later nests were found; but families, with young noisily 

 clamoring for food, were heard all summer long. In the great 

 majority of cases, the broods were of three only; but two broods, 

 at most (and possibly but one of these), exhibiting four young birds. 

 Examination of my small series of crossbills shows that birds of a 

 year old, and a little over, were sexually neutral. 1 These were 

 constantly in company with families containing young. These 

 family groups were noticed throughout the summer of 1905, until 

 September. On the Bear Lodge slopes of Crook County a few such 

 were seen early in September; the mature birds even yet exercising 

 parental care over the juveniles, though not probably feeding them. 

 The young still clamored to be fed; but no act of feeding was 

 clearly and indisputably seen. 



True to the erratic habit of their kind, the Wyoming crossbills 

 were notably few in number during October, 1905. The same 

 condition prevailed into November; an ardent and repeated 

 search among the shale-hill pines revealing but a scattered bird, 

 here and there. Determined, however, to fix the time of nascent 

 breeding conditions, I sought the crossbills at stated times to the 

 end of November. On the 27th I was rewarded by finding what 



1 It should be stated here that both Dr. Bishop and Dr. Dwight consider certain 

 supposedly year-old birds, from the region exploited in this article, to be strictly 

 birds-of-t he-year. One such Dr. Bishop believes to have been hatched from Novem- 

 ber eggs. Other specimens in similar transition plumage were being fed by parents. 

 If the Doctors be right in their judgment in these cases, the problem of nesting time 

 for crossbills in Wyoming is even more complicated than one had previously sup- 

 posed; while the long time of parental feeding becomes thus the more incredibly 

 lengthened. Of course it would be quite impossible for a juvenile crossbill to feed 

 itself before the mandibles were fully developed; yet it becomes a matter of surprise 

 that birds in transition plumage, with fully developed mandibles, should follow 

 parents and clamor for food, being apparently, in such cases, sometimes actually fed. 



It should be added that a fair series of juveniles has been taken in the Wyoming 

 hills for the express purpose of throwing light upon the length of time required in 

 the maturing of the bill of the crossbill. Birds with mandibles about one third 

 developed, while wearing still the juvenile plumage, were taken in late March, April 

 and June; while all birds taken in transition plumage were of perfect beak-develop- 

 ment. Study of records for birds taken do not show that these transition juveniles 

 were any more abundant in March, for example, than they were in late May. 



