Field counts 
ye and estimates Estimates 
Survey date Area of sea otters of total 
19-27 May 1959 Aleutian Islands 9,507 12,665 = 19,014 
Attu Island to the 
Islands of Four 
Mountains 
6 May ~ 28 Sept. Prince William 
1957 Sound © 495 = 530 1,000 - 2,000 
Kodiak-Afognak 583 750 - 1,500 
Alaska Peninsula 3,524 3,900 - 4,950 
Fox Islands 795 1,100 = 1,500 
Total 14,904-14,939 19,415 =-28,964 
Round total 20,000 -30,000 

Areas in need of further study are, the Islands of Four Mountains, 
Fox Islands, Alaska Peninsula, Sandman Reefs, and Shumagin Islands. 
SUMMARY AND CONCLUSIONS 
1. The 1959 aerial survey (19-27 May) of the outer Aleutians was 
successful in revealing sea otter distribution and the size of sea 
otter populations. Favorable weather during the observation period 
contributed in large degree to the confidence we place in our observa- 
tions. A total of 9,507 adult and subadult otters were counted. The 
estimated total population (excluding pups) in the survey area is 
13,000 to 20,000 otters. 
2. The FWS R4D was found to be highly adequate for making sea 
otter surveys in the remote Aleutian area. 
3. Counts made from a boat and from the shore in sample areas at 
Amchitka furnished data that confirmed the aircraft counts and furnished 
approximate limits for estimating the total population from aerial 
counts, that is, 50 to 75 percent of the otters present in survey areas 
were seen. 
4. The areas of heaviest sea otter population are (a) western 
Andreanof Islands (Tanaga, Kanaga, Adak), 4,499 counted; (2) Rat 
Islands, 3,480 counted; (c) Delarof Islands, 1,397 counted. 
5. Otters were not seen and are considered as absent or extremely 
scarce in (a) the Near Islands; (b) the central Andreanof Islands; (c) 
from Amukta Island to Herbert Island, inclusive, and probably in the 
11 
