SEAL FISHERIES 721 



Table 159. Computation of Pribilof Islands Fur-Seal Herd and Number of 

 Sealskins Taken by the Government, 1910-1949.^ 



^ This computation is based upon actual count of harem, idle, and surplus bulls, num- 

 ber of animals killed, and mortality of each age group as determined when the herd 

 was small. Since animal populations seldom increase at a constant rate, the validity of this 

 computation since 1940 is questioned, and information on this subject is being sought in 

 aerial photographic surveys and by other means. 



Source: U. S. Fish and Wildlife Service. 



of gestation being about one year. The females are mature in their second year 

 and give birth to their first young when 3 years old. Males mature when 6 or 7 

 years old. Both males and females have a life span of approximately 15 years. 

 At maturity a fur-seal bull weighs about 500 pounds, and a cow 90 pounds. Pups 

 and cows leave the Pribilofs in November, followed later by the other seals as 

 winter approaches. There is a general dispersal of these animals in the ocean, 

 some going as far south as the latitude of southern California, while others remain 

 in the Gulf of Alaska. It is unusual that more than a handful of fur seals are seen 

 together at any time during the winter months at sea. The "herd instinct" evi- 

 dently is not strong at this time. 



As might be expected fur seals feed on whatever is readily available. On the 

 northward migration along the British Columbia coast herring is important in their 

 diet, but many almost unknown species of fish having no commercial value are 

 eaten also. The principal food throughout their range, and one for which there 

 seems to be a decided preference, is squid. There is no evidence that the Pribilof 

 fur-seal herd is a menace to any existing commercial fishery. 



Because of the polygamous habits of the fur seal and the fact that the sexes 



