164 



NORTH AMERICAN FAUNA 68 



otters per square mile in 1965 may have resulted from emigration 

 from densely populated Kanaga. 



Kanaga Island. — The Murie expedition visited Kanaga in 1936 

 and Williams (1937) states that no sea otters were seen. Natives 

 reported to him, however, that otters did ''occur occasionally or 

 sparingly" there. By 1943, Kanaga was apparently only sparsely 

 repopulated. Joynt (1957) says that in 1943: 



A few stray animals were observed along the south shore of Kanaga but I 

 do not recall ever observing more than 6 or 8 animals on the three or four 

 flights over this area. 



By 1953 the population had increased greatly. In June of that 

 year D. Hooper {in Jones, 1953) spent 21 days on Kanaga. He 

 walked 40 miles of beach and counted 575 otters. After examining 

 a number of inshore areas at Tanaga he estimated that the otter 

 populations of Kanaga and Tanaga Islands were large, "probably 

 numbering several thousand" animals. 



Data obtained on the 1959 and 1962 aerial surveys indicate that 

 the Kanaga population was near maximum size in 1959. The 

 precipitous population drop from an observed total of 1,822 otters 

 in 1959 to 846 in 1962 indicates that the estimated 1959 population 

 of 26 otters per square mile of available feeding habitat may have 

 depleted food resources and precipitated substantial emigration 

 (and mortality?) during the elapsed 3-year period. By 1965 a 

 slight increase, probably resulting from crowding at nearby Adak, 

 had occurred (table 27). 



On a dory survey in 1957 along a 19-mile sample of coast, 

 Lensink (1960) recorded 566 otters. Along the same coastal sample 

 on our 1959 aerial survey we recorded 549 otters and in 1962 the 

 aerial count there was 404. The similarity of the 1957 surface 



Table 27. — Kanaga Island sea otter population density in 95 square miles of 



feeding habitat 







Estimate 



Otters per 



Authority and 



Year 



Count 



of total 



square mile 



survey method 



1943 _ 



6-8 



few 



(?) 



G. T. Joynt (1957) flew repeatedly 

 over area. 



1953 



575 



many 



(?) 



D. Hooper (in Jones, 1953) walked 







40 miles of beach and counted 

 otters. 



1957 



566 



1 3,000-5,000 



32-53 



C. J. Lensink (1960), dory survey 

 along 19 miles of coast. 



1959 - ... 



1,822 



2,429 



26 



Spsncer and Kenyon, aerial survey, 

 entire island. 



1962 



846 



1,128 



12 



Spencer and Kenyon, aerial survey, 

 entire island. 



1965 



1,054 



1,405 



15 



Spencer and Kenyon, aerial survey. 









entire island. 



1 Because this estimate was made from data gathered along the south shore, where more 

 habitat is available than along the north shore, the estimated upper limit may be somewhat high. 



