SEA OTTER POPULATION AND TRANSPLANT STUDIES IN ALASKA, 1959 
PART I 
AERIAL SURVEY OF WESTERN ALEUTIAN AREA, 1959, 
and 
ESTIMATES OF THE SEA OTTER POPULATION OF ALASKA 
This report presents the results of our 1959 aerial survey and 
an evaluation of the survey based on sample boat and shore observa-= 
tions. A discussion of previous population estimates is included, 
together with our estimate of the present sea otter population in 
Alaska. Only adult and subadult otters are considered. Pups still 
with their mothers could not be counted from the air. This aspect 
of the sea otter population will be discussed in a later report. 
Aerial surveys were conducted in the outer (western) islands of 
the Aleutian Islands National Wildlife Refuge in 1959 to furnish 
current information on the distribution of sea otters and the approx- 
imate size of island populations in this area. Between 19 and 27 May 
virtually every Aleutian island west of (and including) Herbert Island, 
in the Islands of Four Mountains, was surveyed. 
The FWS R4D Aircraft N701 itinerary was as follows: 
Date Flight Area 
1959 Takeoff Land hours surveyed 
17 May Anchorage Adak 8.9 None 
18 " #£Adak Amchitka 3.5 Practice counts en route 
19 " (Amchitka Shemya) 9.1 Rat Islands 
(Shemya Amchitka) Near Islands 
20 “  Amchitka St. Paul 4.3 (otter transplant) 
21 “  §t. Paul Adak 3.6 None (poor weather) 
24 " Adak Adak 1.0 None (poor weather) 
25 “ Adak Adak 5.1 Andreanof Is. (part) 
26 " Adak Adak 9.3 Andreanof Is. (part), 
Delarof Is. and 
: Semisopochnoi 
27 "“ Adak King 10.0 Andreanof Is. (part) and 
Salmon Seguam to Herbert Is. 
(Is. of Four Mountains) 
27 “ King Anchorage 2.0 None 
Salmon 
Total aircraft hours 56.8 
er se PnP cS SP 
