and predatory habits cause breeding individ- 

 uals to concentrate at seabird cliffs; 150 pairs 

 bred at Cape Thompson in 1961 (Swartz, 

 1966). During the breeding season it remains 

 near land and is not conjmonly seen far out 

 at sea. Nelson (1883) mentions no pelagic ob- 

 servations; Jacques (1930) found it present 

 but uncommon north to Herald Island. Most 

 observations reported by Swartz (1967) were 

 within 25 miles of land. There are little fall 

 migration data for the arctic coast. Birds 

 which breed inland move to the coast where 

 both adults and young stay until driven south 

 by ice and lack of food. Bailey (1948) observed 

 hundreds passing Wainwright on 16 Septem- 

 ber. The latest date he recorded the species was 

 19 October. 



Glaucous Gulls were observed throughout the 

 cruise (fig. 16). They were abundant at Barrow 

 on 23 September when a flock of 40 individuals 

 followed the ship while it was just south of the 

 pack ice. From Barrow to the study area only 

 small infrequent flocks were seen. They were 

 present throughout the study area but were 

 most common in the northeast portion and at 

 other stations close to the shore. They were 

 present throughout the day in the Bering Strait 

 (fig. 21). The species displayed no obvious 

 afl^inity for ice areas. Approximately 25 percent 

 of all birds seen were immatures (fig. 17). 



Glaucous Gulls tended to flock less than other 

 gulls and single individuals were frequently 

 seen on transects. On the other hand, large 

 numbers gathered about the ship on stations to 

 accept scraps thrown over the side (table III). 

 Most of its food is probably live fish and 

 crustaceans but we also saw it feeding on Wal- 

 rus dung. Hovering, contact dipping and sur- 

 face feeding were all observed for this species 

 (fig. 17). Examination of stomach contents 

 indicates that fish may be the major food dur- 

 ing this time of year (table V). One individual 

 had eaten ascidians including a pyrid, Halo- 

 cynthia sp. or Bottenia sp. and one each of the 

 styelids Polenaia corrugata and Cnemidocarpa 

 sp. (the latter identifications are tentative). 

 Three of the seven specimens collected were 

 adults (table II). 



Slaty-backed Gull (Larics schistisagus) 



On 25 September approximately 20 miles 

 northwest of Point Lay, a large dark-backed 



gull was observed that was most probably a 

 Slaty-backed Gull (Larus schist isagtis) (fig. 14). 

 This is a species of the Siberian Pacific coast 

 and is rarely found in Alaskan waters. A speci- 

 men collected by Bailey at Icy Cape on 16 

 September 1921 was thought to be this species, 

 but according to Bailey (1947) further investi- 

 gation proved it to be the Siberian Lesser 

 Black-backed (Lams fusc-us). A straggler has 

 also been reported for Herald Island (Nelson, 

 1883). 



Herring Gull, (Lanis argevtatus) 



The Herring Gull is found throughout most 

 of the northern hemisphere including the east 

 Canadian Arctic and Siberia but does not breed 

 on the arctic coast of Alaska. In the fall, and 

 probably in the spring, it is a regular but un- 

 common migrant in northern Alaska. The 

 majority of Alaskan migrants are "Thayer's 

 Gull," L. a. thayeri which breeds in arctic 

 Canada and winters along the Pacific coast of 

 North America. We observed this species five 

 times in the study area (fig. 18). Three of the 

 six individuals seen were immatures. Two other 

 sightings were made in the Bering Strait; a 

 single individual at 66'22' N, and a flock of 

 five at 66°05' N. 



This species is an unspecialized feeder 

 similar to L. hyperboreus. The stomach of the 

 second-year bird collected (table II) contained 

 remnants of Arctic Cod (table V) . 



Ivory Gull (Pagophila eburnea) 



The Ivory Gull, a high arctic species re- 

 ported as far north as 86° N (Dementiev and 

 Gladkov 1961), breeds north of 70° N. The 

 known breeding grounds closest to the study 

 area are at Herald Island and in the Canadian 

 Archipelago. Outside the breeding season, it 

 frequents the pack ice, and the southern extent 

 of its wintering range is largely determined by 

 the southern margin of the pack ice. Ivory 

 Gulls move through the Chukchi Sea with the 

 ice in the spring and fall. Small numbers are 

 probably present in the open leads throughout 

 the winter. The pelagic habits of this species 

 have caused land observers to underestimate its 

 abundance in the Chukchi (see, for instance, 

 Gabrielson and Lincoln 1959). It was reported 

 common in the "frozen" Chukchi Sea on Cook's 

 last voyage from August to September 1778 

 and in July 1779 (Stresemann, 1949). It is not 



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