Red-Legged Kittiwake Colonies in the Aleutian Islands, Alaska

Abstract

Nesting colonies of Red-legged Kittiwakes (Rissa brevirostris) have been discovered and censused in two locations in the Aleutian Islands: Buldir Island (52021'N, 175056'E) and Bogoslof Island (53055'N, 168005'W). These are the first confirmed recent breeding records of the species in the Aleutians. Only two other breeding stations are known for the species: the Pribilof Islands, Alaska (Gabrielson and Lincoln 1959) and the Commander Islands, U.S.S.R. (Vaurie 1965). Turner (1885, 1886) reported Red-legged Kittiwakes breeding in the Aleutian Islands. He believed that they were more common than Black-legged Kittiwakes (Rissa tridactyla) in the western Aleutians. Clark (1910) saw Red-legged Kittiwakes near Unalaska Island, eastern Aleutians; he said they became more common in the western Aleutians, apparently based on Turner's statement. Since Clark's work, several investigators (Eyerdam 1936, Gabrielson and Lincoln 1959, Karl W. Kenyon, pers. comm.) have recorded the species in the Aleutians in summer, but nesting has not been confirmed. Gabrielson and Lincoln (1959) thought that Red-legged Kittiwakes did not nest in the Aleutians, apparently because of the lack of breeding specimens, and because no recent investigators had found the species nesting. Murie (1959) did not see Red-legged Kittiwake in the Aleutians during three summers of intensive field work, and he suggested that early reports of abundant nesting (Turner 1885, 1886, Clark 1910) were erroneous. It seems unlikely that population decline of the magnitude suggested by the literature occurred in the Aleutians, so I concur with Murie, that Turner was mistaken. In July 1972, breeding Red-legged Kittiwakes were found at East Cape, Buldir Island. About 2,000 pairs of Red-legged Kittiwakes nested in mixed colonies with their congeners in three areas on Buldir and on two islets off Northwest Point 1974-1976. There is no indication that the status of Red-legged Kittiwakes has changed drastically at Buldir. K. W. Kenyon (pers. comm.) saw the species there in 1963 but was unable to visit the areas where they nest. Weather prevented investigators who visite-d Buldir (Murie 1959, Jones 1963) from investigating the nesting cliffs. In July 1973, 81 nests of Red-legged Kittiwakes (about 10% of all kittiwake nests) were discovered on Bogoslof Island, and 20 nests (among 1,000 Black-legged Kittiwake nests) were counted on Fire Island, small offshore islet. I. N. Gabrielson (unpubl. data) saw this species near Bogoslof in June 1946, when he observed birds flying toward a small isolated rock (Fire Island) which he could not investigate. Gabrielson did not find Red-legged Kittiwakes on Bogoslof, although he looked for them among the numerous Black-legged Kittiwakes. Apparently the species has colonized Bogoslof since 1946, perhaps from Fire Island. At least 20 U.S. Fish and Wildlife Service employees were involved in gathering data contributing to this note. G. J. Divoky, D. D. Gibson, T. G. Tobish, and J. L. Trapp provided especially significant assistance. Captain G. A. Putney of the R/V Aleutian Tern provided expert logistic support. K. W. Kenyon offered encouragement and advice, and I. N. Gabrielson provided copies of his field notes from Bogoslof Island.