186 NORTH AMERICAN FAUNA 61, FISH AND WILDLIFE SERVICE 



One would expect such heavy mortality over a considerable area 

 to be disastrous, but the reproductive rate seems ample to cope 

 with all such natural opposing forces, as well as with predation. 



Cepphus columba: Pigeon Guillemot 

 Cepphus columba kaiurka 

 Attu: Secv-luch 



Siblux (Jochelson) 

 Atka: Seem-luch 



Sinilux (Jochelson) 

 Commander Islands: Kajurka (Stejneger) 

 Russian, Commander Islands: Svistun (Stejneger) 



There may be an error in the Commander Islands names. 

 Stejneger told me that both Aleut and Russian was spoken on 

 those islands. The supposed native name, Kajurka, appears to 

 have the structure of Russian, and Svistun is essentially the same 

 name that Turner found applied to a scoter in the Aleutians, and 

 that I found applied to the American scoter by residents on Uni- 

 mak Island. The race found in the Commander Islands is C. c. 

 kaiurka. 



The pigeon guillemot is so universally distributed, from Kodiak 

 Island to Attu, that an enumeration of localities is superfluous. 

 Along the north side of Alaska Peninsula it was observed at 

 Moller Bay by Jaques (1930), and specimens have been taken 

 at Nushagak. 



Usually they are found in small groups. Possibly the largest 

 aggregation was a loose band of 40 seen at Chugul Island, west 

 of Atka. They nest among boulders on the shore or in crevices 

 of cliffs. 



Birds were occasionally seen with an unseasonable whitish 

 suffusion on the plumage, suggesting the winter dress. The first 

 one was noted June 24, 1937, at Davidof Island, and another 

 was noted on June 26, at Little Sitkin. Several were noted at 

 Rat Island, June 30; several were seen at Tanaga on August 3; 

 one was seen at East Unalga, August 26; and several were seen 

 at Sanak on August 29. During this period the vast majority 

 were, of course, in the plain black summer dress. 



Apparently, two races of this guillemot breed in the Aleutians. 

 Robert W. Storer (1950) has described Cepphus columba adianta, 

 giving its range from the mouth of the Columbia River "north to 

 and including the Alaska Peninsula and the Aleutians at least as 

 far west as Umnak Island." This would leave the Aleutians west 

 of Umnak and the Commander Islands to the race Cepphus 

 columba kaiurka. I have not had an opportunity to investigate 

 this, but the A.O.U. Check List has not recognized the validity 



