NO. 2 BIRDS OF ALASKA AND SIBERIA — HERSEY I3 



fully adult with white underparts, head and tail and light pearl gray 

 mantle. The proportion of adults in the flocks about the ship was 

 small as most of the old birds were attending to their domestic 

 duties. I doubt if any number ever assume full adult plumage until 

 the third winter or breed before they are three years old. The great 

 amount of variation in the plumages of the immature birds seems to 

 indicate this, the differences being too great to be merely individual 

 variation in birds of the same age, that is, one year old or less, which 

 would necessarily be the case if the birds become adult and breed 

 when two years old. 



It may be of interest to mention that, in company with Mr. D. E. 

 Brown, I took a Glaucous Gull on Tacoma Bay, May 2. Dawson 

 and Bowles, in the " Birds of Washington," mention the species only 

 in the " hypothetical list." 



LARUS GLAUCESCENS 



Glaucous-winged Gull 



A large number of these gulls followed us from Seattle to Ketchi- 

 kan. Upon our arrival they were joined by others and were the most 

 common species in southeastern Alaska. At Unalaska they were 

 abundant and very tame, and throughout the southern part of 

 Bering Sea were continually seen. None were observed north of 

 St. Michael. 



LARUS SCHISTISAGUS 



Slaty-backed Gull 



A small number were seen from the steamer on the homeward 

 trip, when only a few hours out from Nome. They were easily 

 identified among the Pacific Kitti wakes and Glaucous Gulls. 



LARUS OCCIDENTALIS 



Western Gull 



LARUS ARGENTATUS 



Herring Gull 



Both these species were common about Seattle and quite a number 

 of the latter followed us thrc ugh the " inside passage " to Ketchikan. 

 Among the Herring Gulls were about an equal number of Western 

 Gulls quite conspicuous by their darker colored backs. These grad- 

 ually left us, a few at a time, until by the time we anchored at 

 Ketchikan there were not more than four remaining. 



