NORTH AMERICAN FAUNA 68 



1962 



1959 



1962 



1959 



1962 



1963 



1959 



1959 



1956 



1959 I 



1956 



1956 

 1955 



1955 



1957 



1957 



1957 



1961 

 1958 



JAN. 



FEB. 



MAR. APR. MAY 



MONTH OF DEATH 



JUNE JULY 

 OF SEA 



AUG. SEPT. 

 OTTERS 



OCT. NOV. DEC. 



Figure 96. — Observed mortality of sea otters at Amchitka Island, 1955-63. 

 Each bar represents the number of otters that were found dead and were 

 estimated to have died in the indicated month and year. Otters dead so 

 long that the month of death could not reasonably be estimated are ex- 

 cluded. Data from 259 dead otters were used in this graph. No freshly dead 

 otters were found in June, July, or August of 1955, in July of 1956, or in 

 November of 1957. 



diving, habitually beg for and receive food from the mother. The 

 result of this behavior is that mothers are unable to obtain suf- 

 ficient food for themselves and their large offspring during periods 

 when heavy seas render food gathering difficult. For this reason, 

 many mothers desert their large young at this season of stress. 

 Deserted juveniles were seen searching and screaming for their 

 mothers in the late-winter, early-spring period. 



For example, a mother and a pup, weighing about 12 lb. (5.4 

 kg.), were captured together and tagged on 15 February 1962. 

 When released they swam off together. Both appeared thin but in 

 normal health. On 18 February, the juvenile was found wander- 



