1926] Swarth: Birds and Mammals from the Atlin Region 63 



seen continually in some numbers along the lake shore, and the species 

 was probably nesting at various points. We did not discover the 

 colony alluded to above until all young birds had left the nests. Due 

 to the ravages of the herring gull, as seemed evident, eggs and young 

 in this colony were destroyed until just one young bird remained. This 

 lone survivor, with wing quills partly grown but not yet able to fly, 

 M^as several times seen, swimming on the lake, dodging attacks from a 

 herring gull, which persisted until the entire adult population of 

 short-billed and Bonaparte gulls came to the rescue. 



A short-billed gull's nest was discovered July 15 on the "middle 

 island" opposite the town of Atlin. It was placed in the top of a 

 small balsam fir (with which trees these islands are thickly covered), 

 about fifteen feet from the ground, and not at all easy to see in the 

 flattened tree-top where it was placed. The young had been gone for 

 some days at least, and buried in the bottom of the nest, entirely 

 covered and hidden, was an addled egg (no. 1978). One or two other 

 nests were seen in similar situations. 



Two specimens of short-billed gull were preserved, an adult male 

 (no. 44628) taken June 15, and a young female (no. 44629) molting 

 from down to first winter plumage, taken July 14. 



Larus Philadelphia (Ord). Bonaparte Gull 

 Seen at Carcross, May 22. Two days later a pair of these birds 

 had apparently preempted one end of a slough at the edge of the 

 town, and they dived at our heads with loud outcries whenever we 

 approached. 



At Atlin, this species, like the short-billed gull, was nesting on the 

 islands opposite the town, and, as with the larger species, the young 

 had left the nests before we discovered this breeding ground. There 

 were apparently ten or twelve pairs of Bonaparte gulls domiciled upon 

 the islands, and, due again to the raiding herring gulls, from all these 

 broods but three young birds reached an age when they could fly. 



Several nests were found on the islands, which, without question, 

 must have belonged to this species. They were frail affairs, not much 

 larger than waxwings' nests, placed on widespreading side branches 

 of balsam firs, near the tops of the trees, some fifteen or twenty feet 

 from the ground. Just as is seen in the descriptions of Bonaparte 

 gulls' nests given by the several authors that are quoted in Bent's 

 (1921, p. 176) "Life Histories," they were suggestive of pigeons' 

 nests more than anything else. 



