200 



NORTH AMERICAN FAUNA 68 



14. In addition to the many areas in western Alaska offering 

 sea otter habitat which today is unpopulated, approximately 2,000 

 miles of coastline, including much sea otter habitat, separates the 

 colony at Kayak Island, Alaska, from the small central California 

 colony. 



15. Several aerial surveys were made in 1958 and 1964 to 1966 

 along the California coast. The highest counts in 1958 and 1966 

 yielded 638 and 618 sea otters, respectively. Further surface and 

 aerial surveys, begun in August 1968, yielded a high count of 

 1,014 otters (Peterson and Odemar, 1969), indicating a population 

 increase since 1958 of about 5 percent per year. 



16. The number of otters recorded during aerial and limited 

 surface surveys in Alaska was 17,964 and the total population in 

 Alaska waters in 1965 is estimated to be about 25,000. 



17. The most recently published Soviet total estimate of sea 

 otters in Soviet waters is 5,300. 



18. On the basis of all data available, the world population of 

 sea otters in 1965 was computed to be 32,909. A general estimate 

 of the world population, presuming that some populated areas 

 have not been observed, is about 32,000 to 35,000 animals. 



19. Measurements of available sea otter habitat, much of which 

 was not occupied in 1965, and the observed population density of 

 relatively stable populations (10 to 15 otters per square mile of 

 habitat) indicate that the Aleutian Islands and closely related areas 

 of the Alaska Peninsula may eventually support a population of 

 about 50,000 to 74,000 sea otters. 



Home Range 



The purpose of permanently marking sea otters is to obtain 

 from field observations and recovery of tags, over a period of time, 

 the following information on the life history of individual animals : 

 (1) Maturation, (2) aging, (3) longevity, (4) reproduction, and 

 (5) movements and home range. 



Sea otters were captured on shore with a sport fisherman's 

 landing net (fig. 82). While the netted otter struggled to free itself, 

 using forepaws and teeth on the net, one rear flipper was grasped 

 and a cattle or sheep ear tag of monel metal (table 39) was clamped 

 to the web of the hind flipper with a special pliers. Two men were 

 required, one to hold the net and the other to affix the tag. Colored 

 plastic strips were attached experimentally to some tags, so that 

 individual animals might be recognized in the wild. 



