160 



NORTH AMERICAN FAUNA 68 



took place. After the Tanaga population exceeded the carrying 

 capacity of the available habitat, otters moved westward to the 

 Delarofs again as well as eastward to Kanaga and Adak. Thus, 

 we observed a second population peak in the Delarofs in 1959. 

 This resulted in food depletion and a subsequent ''population 

 crash" bringing the population density from 21 down to about 10 

 otters per square mile by May 1965 (table 24). Whether oil from 

 the San Patrick, which was wrecked on the south shore of Ulak 

 Island during the winter of 1964-65, was a factor in population 

 reduction is not known. 



Andreanof Islands 



The Andreanof Islands (figs. 76 and 77) (excluding the Delarof 

 group) extend for a latitudinal distance of about 230 miles from 

 Tanaga on the west to Seguam on the east. Human populations 

 in this group are at the U.S. Naval Station on Adak, and Atka 



Great Sitkin 

 (and nearby islands) - -68 5 



!78° .10 Mi.. 176° 



Figure 76. — The Adak-Great Sitkin Island areas in the central Andreanofs 

 were repopulated during the 1950's and early 1960's by otters from the 

 Delarof and Kanaga and Tanaga Islands. No otters were found on a survey 

 of Adak in 1952, but on an aerial survey in 1954 a count of 48 was obtained, 

 and by 1965 the count increased to 1,336. On aerial surveys of 25 and 26 

 April 1965, 3,239 otters were observed in the area shown. 



