[2.90] BIRDSOFOREGON 



abundant gulls found in Oregon and has been recorded for every month 

 and from every county. Somewhat smaller than the Western and Herring 

 Gulls and larger than the Ring-billed, it is one of the species that make 

 for confusion in the identification of gulls. It can be distinguished from 

 the Western Gull by its much paler back and by its paler under parts in 

 comparable plumages, but it is more or less easily confused with the 

 smaller Ring-billed Gulls, particularly by those who are just beginning 

 the study of birds. 



In general, the California Gull, the most abundant breeding gull in 

 Oregon, will be found during the breeding season in the great alkaline 

 lakes and swamps in the eastern part of the State, where it forms huge 

 nesting colonies (Plate 47, B). In these great interior nesting colonies, 

 nest construction and egg laying usually start in late April or early May, 

 and young birds commence to hatch in increasing numbers around June i. 

 There is great variation in the nests built. Some of them are fairly com- 

 pact structures of dry grass and other vegetation, and in some cases the 

 eggs are laid on almost bare ground. The gulls stay as long as there is 

 open water, and stray individuals remain along the Columbia, Snake, 

 and Klamath Rivers well into the winter, if not through the entire season. 

 There are colonies at Malheur Lake in the Harney Valley, at Summer 

 Lake in the Warner Valley, and usually one or more on Upper Klamath 

 Lake in the Klamath Basin; and recently a colony has been established 

 in Spring Lake, a small pond a few miles out of Klamath Falls. There is 

 a colony just across the line on the Clear Lake Reservation in California. 



The colony in Harney Valley has been written about by every observer 

 who has traveled this country since Bendire's time. In some years, it is 

 on Malheur Lake, in others in some of the other swamps in the valley, 

 and frequently during the past few years has been on the Island Ranch 

 north of Malheur Lake. There, in 192.6, the season when we made the 

 last careful inspection of the colony, we estimated that on a little sage- 

 and greasewood-grown island there were between 1,500 and i.,ooo pairs 

 of California Gulls nesting and a smaller number of Ring-billed Gulls and 

 Caspian Terns. At the time of our visit on June 4, numerous nests con- 

 tained two or three fresh-looking eggs and there were many young just 

 hatched and quite a number grown to the size of pigeons or larger that 

 were able to walk and swim off in little groups as we approached the 

 island. 



The visit to this colony, as to all other great bird rookeries, was an 

 exciting event. From a distance the colony looked like gigantic swarms 

 of bees, circling and darting as the parent gulls traveled to and from their 

 feeding grounds to the colony. As the intruders approached, a constantly 

 growing swarm of gulls hovered overhead until the screaming became 

 almost deafening. The colony, as usual, was filthy and odoriferous. The 

 birds had been feeding the young on grasshoppers, and the surface of the 



