150 



NORTH AMERICAN FAUNA 68 



ticularly in 1964 and 1965, and present day Defense Department- 

 Atomic Energy Commission weapons testing activity. 



The Rat Islands are noteworthy because it was at Amchitka 

 Island that the first indication of substantial recovery of a sea 

 otter population was noted in 1935. An aerial survey covering all 

 of the Rat Islands was conducted in 1959. Attempts to repeat the 

 survey in 1962 failed because of prolonged harsh weather, but a 

 successful survey was made 2 May 1965. The survey data are 

 recorded in table 21. 



Individual islands from which data of particular interest are 

 available are discussed below. 



Buldir Island. — This island is 55 miles west of Kiska and is the 

 most isolated of the Rat Islands group. Apparently, for this 

 reason it was the last to be repopulated. No otters were seen 

 during an aerial survey 19 May 1959, but this survey was unsatis- 

 factory because of poor weather conditions (wind and fog). The 

 first modern report of sea otters at Buldir was made by R. D. Jones 

 (1963). He saw an adult male and three females with young there 

 during a visit, 25-28 June 1962. In 1963, between 7 and 19 July, 

 our party recorded five mothers with young and four lone adults 

 on a partial surface survey which included the north coast of the 

 island. 



On 2 May 1965 aerial survey conditions were fair (wind 10-15 

 knots and sun glare) and 15 otters were seen. Numerous sea lions 

 were also present, making observations somewhat difficult. It seems 

 probable to us that the total sea otter population does not exceed 

 30 animals. 



Murie (1940 and 1959), and Williams (1937) did not find sea 



Table 21. — Eat Islands group, sea otter population density, estimated from 

 aerial survey counts, 19 May 1959 and 2-3 May 1965 



otters estimated 



Otters counted Estimated total Square per square mile 



miles of 



Island 1959 1965 1959 1965 habitat i 1959 1965 



Buldir 2 _ 15 _ 30 13 — 2 



Kiska, L. Kiska, 



Tanadak I. and Pass 1,127 1,229 1,503 1,652 78 19 21 



Segula-.__. 47 56 63 75 7 9 11 



Pyramid, Davidof, 



Khvostov 33 39 44 52 8 5 7 



Little Sitkin 50 135 66 180 15 4 12 



Rat 270 326 360 435 30 12 15 



Amchitka 1,560 1,144 2,078 1,525 110 19 14 



Semisopochnoi 393 203 524 271 32 16 8 



Total 3,480 3,147 4,638 4,220 293 12 11 



1 Square nautical miles of water 30 fathoms or less in depth. 



2 At Buldir Island in July of 1963, 9 otters were counted from the surface along 4 miles of 

 the 10-mile shoreline. The estimated total in that year was 25 otters. 



