NESTING SEABIRDS OF THE GULF OF ALASKA 



59 



Black-legged Kittiwake (Rissa tridactyla) 



The black-legged kittiwake is the most 

 abundant gull in the northern and western 

 Gulf of Alaska. Colonies of this species can be 

 found throughout the entire area, and range 

 in size from a few pairs (Class I) to more than 

 100,000 birds (Class V). They may be found in 

 essentially pure colonies, but are often found 

 sharing colonies with murres. 



The center of abundance for breeding black- 

 legged kittiwakes in the Gulf of Alaska is in 

 the Semidi Islands, where Palmer Sekora 

 (U. S. Bureau of Sport Fisheries and Wildlife 

 1973) estimated that there were 426,000 

 breeding kittiwakes in 1972. He located kitti- 

 wake colonies at eight sites, ranging in size 

 from 1,000 to 109,000 nesting birds. The size 

 of the average colonial site was 27,000 birds. 

 Ten sites were Class IV in size and one was a 

 solid Class V. 



The easternmost known colony in the north- 

 ern Gulf of Alaska is at Wingham Island. Up 

 to 1973, 22 colonies had been located in Prince 

 William Sound. The largest of these contained 

 only 5,636 nests in 1972 (Isleib and Kessel 

 1973). Class IV or larger colonies are found at 

 Cape Resurrection, the Barren Islands, Chisik 

 Island, Boulder Bay and Cape Chiniak on 

 Kodiak Island, and at Delarof Harbor and the 

 Haystacks in the Shumagin Islands. It is in- 

 teresting to note that Gabrielson (1940) con- 

 sidered Whale Island to be one of the largest 

 known kittiwake colonies in Alaska. He stated 

 that there were many thousands of pairs ex- 

 tending over a mile or more of cliff. He saw a 

 second site which he did not visit but looked 

 equally large. A photograph in an article by 

 East (1943) also indicated the presence of a 

 large colony. C. J. Lensink (personal com- 

 munication) estimated that there were about 

 100,000 kittiwakes in the colony in 1956. 

 When last visited by Vernon Berns (personal 

 communication), this colony contained only 

 3,000 birds. It is also of interest that Gabriel- 

 son (1940, 1944) did not notice either the kitti- 

 wakes or the murres now breeding on Nord Is- 

 land in the Barren Islands or the kittiwakes 

 on East Amatuli Island. 



Whale Island and possibly the colonies in 

 the Barren Islands give evidence of local 

 population fluctuations, but for the most part 

 I have not found an indication of a major per- 



turbation over the past 40 years. Before 1936, 

 the record is too fragmentary to allow an 

 assessment. 



One of the interesting aspects of kittiwake 

 ecology in the Gulf of Alaska is the common 

 occurrence of breeding failure. David Snarski 

 (December 1943 Quarterly Progress Report, 

 Alaska Cooperative Wildlife Research Unit, 

 University of Alaska) observed breeding fail- 

 ure on colonies in the Tuxedni National Wild- 

 life Refuge in 1970 and 1971 and obtained cir- 

 cumstantial evidence of another failure in 

 1972. In 1973 all of the breeding cliffs were 

 occupied and nesting was successful. What- 

 ever the cause of these periodic failures, they 

 do not yet appear to have had a permanent 

 impact that we are able to measure. 



Red-legged Kittiwake (Rissa brevirostris) 



Red-legged kittiwakes are not now known 

 to breed in the western Gulf of Alaska. Turner 

 (1886) stated that he saw a few at Sanak in 

 1878. We also have Stejneger's (1885) state- 

 ment, that "red-legged" kittiwakes nest from 

 Bering Island to Sanak. Friedmann (1937) re- 

 ported two humeri from Kodiak Island 

 middens. During the summer of 1976, two 

 birds were observed off Kodiak Island by 

 Irving M. Warner (personal communication), 

 and one at 158W and 5430'-5420'N south 

 and east of the Shumagin Islands (Patrick J. 

 Gould, personal communication). 



Turner (1885) listed the red-legged kitti- 

 wake as abundant and breeding in the Near 

 Islands. Turner (1886) also stated that he had 

 seen quite a number about a cliff back of the 

 village on Akutan Island in 1878. He added 

 that to the westward this kittiwake was more 

 abundant than the black-legged kittiwake. 

 Murie (1959) expressed the opinion that 

 Turner had confused the short-billed gull with 

 the "short-billed" kittiwake. Clark (1911) also 

 reported that he had seen the red-legged kitti- 

 wake in small numbers near Unalaska and 

 that they became progressively more common 

 west to the Near Islands. Nelson (1887) re- 

 ported seeing large numbers of red-legged 

 kittiwakes at Unalaska. Murie (1959) and 

 Gabrielson (1940, 1944) did not see any red- 

 legged kittiwakes in the Aleutian Islands. The 

 species has recently been discovered breeding 

 at Buldir and Bogoslof islands (G. Vernon 



