these are pmbably the Siberian race L. argentatus vegae (Sowls 

 etai. 1978). Trukhin and Kosygin ( 1987) recorded numbers 

 of these birds on the order of hundreds to thousands between 

 February and August 1963-65 and 1983-84 in the Gulf of 

 Anadyr. Although they were considering a wide variety of 

 factors influencing distribution (e.g., sea ice. breeding, and 

 nonbreeding periods combined), it may be that this species was 

 not adequately sampled during the study described here or that 

 abundances or distributions of this species within this area are 

 changing through time. 



Glaucous gulls are relatively more numerous and are not 

 found south of 59°N( Sowls fM/.. 1978). Breeding birds occur 

 on St. Matthew and Hall Islands, St. Lawrence Island, and 

 much of the northwest coast of Alaska, including Norton 

 Sound. Pelagic densities reported here are similar to those 

 found previously for the study area (Trukhin & Kosygin, 

 1987). 



Blacklegged Kittiwake (Rissa tridactvla) . In Alaska, an 

 abundance of black-legged kittiwakes breed throughout the 

 northern Bering Sea. These breeding populations are estimated 

 to be over 1.3 X 10'' birds (Sowls eft//., 1978). 



This kittiwake has been classified as a shallow-diving 

 piscivore for this analysis, although they are known to eat 

 crustacean prey as well, in small amounts. This species was 

 found in the greatest density in CCW, at three times the density 

 observed in ASW. In BSW, kittiwakes were not observed on 

 the water or taking prey. 



Common Murre {Vria aalee) and Thick-billed Murre 

 (U. lomvia) . Murres are classified here as deep-diving 

 piscivores, although a small fraction of the thick-hilled murre" s 

 diet may also consist of zooplanktonic crustaceans. Breeding 

 colonies of these birds are widespread throughout islands and 

 coasts of the north Bering Sea: St. Matthew and Hall Islands. 

 Karaginskiya Island, St. Lawrence Island, the Diomede Islands, 

 and coastal cliffs of Alaska and the Chukchi Peninsula all 

 support nesting murres, totalling over 2x10'' birds (Sowls 

 etai., 1978; Gerasimov, 1986; Vyatkin. 1986; Kondratiev & 

 Kitesky, unpubl. data). 



The two murre species are sometimes difficult to distinguish 

 at sea, so that densities were calculated for unspecified "murres" 

 as well as for each species when available. Common murre 

 density in CCW was 17 times their density in BSW. This 

 species was not observed on the water in ASW. Thick-billed 

 murres were less common in the study area; these birds were 

 found only in ASW in low numbers. The density of murres not 

 distinguished to species followed the general pattern of common 

 murres described above, as did densities of total murres (all 

 murre data considered collectively regardless of species). 



Pigeon Guillemot ( Cepplnis columha) . Only one individual 

 ofthisspecies was seen flying over ASW. No conclusions may 

 be made as to its habitat preferences in this study. 



Parakeet AukletfCvc/or/'/nvu/H/.v/^.s /?/(/('»/(;) . This species 

 breeds on St. Lawrence Island, King Island, the Diomede 

 Islands, and in small numbers at a few points along the 

 mainland Alaska coast where suitable crevices are available 

 (Sowlsffrt/., 1978). It is estimated that 1 x 10' parakeet auklets 

 nest on the southern portions of the Chukchi Peninsula 

 ( Kondratiev & Kitesky, unpubl data). Nesting is also assumed 

 on Karaginsky Island (Gerasimov, 1986). Parakeet auklets 

 were observed in very low densities in BSW and ASW, and 

 they were not found at all in CCW. 



Crested Auklet (Aethia chstatella) . These deep-diving 

 planktivores nest in large numbers on the St. Matthew and Hall 

 Islands, St. Lawrence Island, King Island, and the Diomede 

 Islands. North Bering Sea populations are estimated at 1 x 10* 

 birds. Crested auklets were absent from CCW, and the density 

 found in ASW was about two times that found in BSW. 



Least Auklet (A. pusilla) . Like the other auklet species. 

 Least Auklets prey on zooplankton, primarily crustaceans, and 

 are capable of relatively deep diving. This species could be the 

 most abundant breeding seabird of the north Bering Sea, with 

 breeding populations totalling about 2.3 x 10" (Sowls et ai. 

 1978). Breeding colonies are located at St. Matthew Island, 

 St. Lawrence Island, King Island, and the Diomede Islands. 

 Densities of least auklets were approximately the same in ASW 

 and BSW, but low in CCW. 



Auklet species . Small numbers ofauklets observed during 

 this cruise could not be identified to species. Birds in this 

 classification showed the same trends as for the identified 

 auklet species (i.e., absent from CCW and found in similar 

 abundances between ASW and BSW, with the density in ASW 

 only slightly exceeding that of BSW ). Previous work indicates 

 that the absence of auklets from coastal waters (i.e.. ACW) 

 occurs across the north Bering Sea ( Hunt t7 o/. , 1 98 1 ; Day et al. , 

 in prep.). 



Tufted Puffin jFratercula cirrhata) and Homed Puffin 

 (FnilercuUi conncidata) . These two species occurred at very 

 low densities only in BSW, although small breeding colonies, 

 primarily of horned puffins, occur on island and coasts 

 throughout the north Bering Sea. Both species breed in the 

 greatest numbers in the Gulf of Alaska. Other observations 

 (Schauer, unpublished data) east of the Convention Line have 

 shown both species of puffins to be present in significantly 

 higher densities at sea in ACW than in ASW or BSW. Because 

 ACW was not sampled during this study, it is probable that 

 puffins were not present in the cruise track rather than being 

 undersampled. Based upon the low densities reported here, 

 little can be concluded about their habitat preferences in this 

 study area. 



396 



