54 



L. W. SOWL 



historical abundance cannot be derived from 

 the existing information. There is strong sus- 

 picion that the introduction of fox on many of 

 the islands in the area during the early part of 

 this century probably caused a reduction in 

 their numbers. Murie (1959) said that experi- 

 ence taught him that wings left from fox kills 

 or remains of storm-petrels in fox droppings 

 could be accepted as evidence of the presence 

 of a colony. Gabrielson and Lincoln (1959) re- 

 ported that E. P. Walker visited the Wooded 

 Islands in 1922 searching for a storm-petrel 

 colony that had been reported to exist there in 

 1918. He could not find it even though he 

 searched diligently. This apparent disap- 

 pearance was attributed to the introduction of 

 fox. 



There is another factor to consider, how- 

 ever. The limited number of specimens now 

 available from the Gulf of Alaska indicates 

 that separate subspecies occupy the eastern 

 and western Gulf of Alaska. The accepted 

 boundary is somewhere in the vicinity of 

 Prince William Sound. This is an indication 

 that there has been a hiatus in this area of 

 rather long duration. I have speculated that 

 this sort of break may be in some way related 

 to the length of day and a period during the 

 summer when there is little darkness to cover 

 activities near the colony. Thoresen (1964) 

 and Cody (1973) have both reported that west- 

 ern gulls (Lams occidentalis) assemble in 

 Cassin's auklet colonies on moonlit nights to 

 prey on arriving adults. It is likely that other 

 nocturnal species would provoke the same 

 sort of hunting tactic. A light-related preda- 

 tion factor implies that the predators rely on 

 sight. Avian predators are indicated. 



Leach's Storm-petrel 

 (Oceanodroma leucorhoa) 



Even less well understood than the breeding 

 distribution of the fork-tailed storm-petrel is 

 that of Leach's storm-petrel. 



Bendire (1895) quotes notes from Chase 

 Littlejohn, who found Leach's storm-petrel to 

 be an abundant breeder on unspecified small 

 islands near Sanak in 1894. It greatly out- 

 numbered the fork-tailed storm-petrel. On his 

 visit in 1937 Murie (1959) learned that all of 

 the large colonies of seabirds that had once 

 existed there were gone. He attributed this to 

 overfishing and associated perturbation and 



to the introduction of fox. No systematic as- 

 sessment of seabirds on Sanak has been at- 

 tempted since Littlejohn 's time. 



No Leach's storm-petrel colonies have been 

 encountered during reconnaissance surveys of 

 the Gulf of Alaska. Small numbers have been 

 reported from time to time and while it is very 

 much less abundant than the fork-tailed 

 storm-petrel, I expect that it will be found in 

 small numbers at various places in the Gulf of 

 Alaska when it becomes possible to make 

 more thorough searches. It may occur in re- 

 mote areas like the smaller islands scattered 

 throughout the Sandman Reefs possibly 

 even in large numbers. On the basis of the 

 Sanak record, we must assume that this 

 storm-petrel has been greatly reduced in num- 

 bers, at least in the western portion of the 

 Gulf. 



Double-crested Cormorant (Phalacrocorax 

 auritus) 



The white-crested cormorant, the race of 

 the double-crested cormorant residing in the 

 Gulf of Alaska, is principally an inhabitant of 

 the marine environment. This cormorant is a 

 common, but apparently patchily distributed, 

 resident throughout the northern and western 

 Gulf of Alaska. 



Gabrielson and Lincoln (1959) thought that 

 it nested only from Kodiak Island westward 

 into the Aleutians. However, it probably 

 breeds from Yakutat Bay westward. Isleib 

 and Kessel (1973) estimated the abundance of 

 the double-crested cormorant along the North 

 Gulf Coast as several thousands, about one- 

 tenth as common as the pelagic cormorant. It 

 is the third most abundant of the four cor- 

 morant species nesting in the area. It occurs 

 as scattered inclusions in many colonies 

 throughout the area, and at least in the Shu- 

 magin Islands, even occurs in some colonies 

 by itself. 



There are no data on which to base an esti- 

 mate of any change in status. It probably is 

 not much affected by many of the naturally 

 occurring perturbations. 



Brandt's Cormorant (Phalacrocorax 

 penicillatus) 



On 22 July 1972, 13 Brandt's cormorants (4 

 sitting on nests) were found at Seal Rocks in 



