LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 273 



amination of fresh material. I can not do better than to quote 

 from his conchisions, as follows : 



It will be necessary first to remark that these birds raise two broods during- 

 the summer. This is not to be understood as a positive statement that the 

 same parents rear two sets of young every year — although I believe that most 

 of them do — but simply that I have found the colonies of this species having 

 eggs and downy young at two different times. The first season commences 

 early in May, the young of this brood being fully fle<lged in the latter part of 

 July. In the middle of this month, however, the colonies again contained 

 all stages, from fresh eggs to newly-hatched young. During the first days 

 of August I found downy young of almost the same age and still without 

 feathers, while on the 21st of August, 1S82, I visited a numerous colony at 

 Poludjonnij, Bering Island, in which the oldest young were about half fledged. 

 These would not be able to fly before the first week of September. Between 

 the two periods, young in all stages of development will be found in the 

 colonies, but proportionately few in number. It will thus be seen that it Is 

 safe to assume that the difference in age between the earliest and the latest 

 born young in one year amounts to three months, at least. 



We are now prepared to understand that we can find two birds undergoing 

 the corresponding molt at times as much apart as the birthdays of the same 

 two birds. If the first molt occurs, say, ten months after the bird broke 

 the shell, the bird born in the middle of May will molt in the middle of March 

 next year, while the one born in the middle of August will not molt before 

 the middle of .Tune next year. And this conclusion is borne out fully by the 

 observed facts. As will be seen from the details relating to the birds col- 

 lected by me, as given below, I shot birds in the latter part of February, both 

 younger and older, which were just in the first stage of molting, while, on 

 the other hand, I have a skin before me In full molt from young to adult 

 plumage, as late as July, a discrepancy hardly to be accounted for, except by 

 the above explanation. 



When about ten months old, the first plumage, which is of the dark grayish 

 sooty color, with some green and purplish reflections in the fresh plumage, 

 changes into the resplendent garb of the adult, from which it then is un- 

 distinguishable, except by not having the bright colors of the naked parts 

 of the face and by lacking the white feathers on the neck and thighs. In the 

 following spring, or when about twenty-three months old, it begins to breed. 



The above conclusions seem to be substantiated by what materia] 

 I have examined ; I have seen young birds molting into adult plum- 

 age in May, June, Jul}-, and September, showing that the molt is 

 much prolonged or very variable, probably the latter. Adults have 

 a complete postnuptial molt during the summer and early fall and 

 a partial prenuptial molt in February, March, and April. The 

 highest nuptial plumage, including the white flank patches, the two 

 crests on the head, and the white filaments on the neck and back, 

 is worn during March, April, and May; the white filaments are 

 very brittle and soon disappear; they are seldom seen in museum 

 specimens, as they are easily lost in skinning. The winter plum- 

 age is duller or browner than the nuptial and lacks the special adorn- 

 ments mentioned above. 



