202 TJ. S. NATIONAL MUSEUM BULLETIN 217 



Peter Lord said that large gulls did not remain on Crow Flats in 

 summer. In June we obtained two specimens of herring gulls on the 

 Porcupine River and saw a number of adults apparently settled. 

 The male specimen, in adult plumage on June 11, by the size of its 

 testes was judged to be not then in breeding condition. The female in 

 second-year plumage had eggs somewhat enlarged, but is supposed not 

 to lay for another year. We saw no glaucous gulls on the Porcupine 

 after migration. 



The two specimens were identified as Larus argentatus smithson- 

 ianus and not L. a. thayeri. Judging from the date they were sam- 

 ples of the summer resident birds and do not represent the migrating 

 gulls with dark wing tips, which might have included thayeri in the 

 great transarctic flight which carries them from their Pacific winter- 

 ing place as far east as Greenland. Thayer's gull is abundant in winter 

 in southern British Columbia (Munro and Cowan, 1947, p. 117), and 

 it is remarked in migration along the southeastern coast of Alaska. 

 Apparently the next common records are from the Alaskan arctic 

 coast, where numerous specimens have come from the vicinity of 

 Barrow. There Thayer's gull is reported as a regular fall migrant 

 by Bailey (1948), who remarks that there are few spring records. 

 It might be that the spring migration of Thayer's gull crosses arctic 

 Yukon from the Gulf of Alaska. Such a course is apparently taken 

 by black brant. 



If we believe that the association of glaucous and herring gulls 

 has been maintained since their departure from the sea, the migra- 

 tory course has probably not followed the Yukon River from Bering 

 Sea, because glaucous gulls seldom pass up the River (Dall and Ban- 

 nister, 1869) , and such a migration as we saw at Old Crow would prob- 

 ably have been noticed. Glaucous gulls have not been earlier reported 

 south of the arctic coast in Yukon (Rand, 1946) nor have they been 

 remarked at Atlin (Swarth, 1936). However, Nelson (1887, p. 62) 

 reported that fur traders had taken glaucous gulls at Fort Reliance, 

 on the upper Yukon, on September 28 and October 18 when ice cov- 

 ered the river. He also remarked that Dall had obtained the young 

 from the famous arctic collector Lockhart, who found them at Fort 

 Yukon. The mystery of how these conspicuous gulls could pass unob- 

 served from the Gulf of Alaska or the Peninsula to Old Crow should 

 check speculation, were the answer less interesting. 



Larus canus brachyrhynchus Richardson 



1 male May 16 weight 435 g. very fat testes 12x20, 11x14 



mm. 

 1 female May 16 weight 436 g. very fat egg 5 mm. 



Three mew gulls on May 3 were the earliest gulls seen flying over 

 the frozen river. Until May 9 groups as large as 12 settled on the 



