Females can be roughly separated into three 

 age groups by the color of their whiskers. Dark- 

 whiskered females are rarely over 4 years old, 

 those with mixed dark and white whiskers are 4 

 to 6 years old, and those with white whiskers are 

 usually 7 years or older. Thus the commercially 

 valuable, young, female seals may be readily se- 

 lected because of a fortunate combination of lo- 

 cation, time, and physical appearance. 



Future harvests of fur seals on the Pribilof 

 Islands will continue to be composed of both 

 sexes. Reproducing females range from 4 to 

 over 20 years of age. The abundance of any 

 age group depends upon its success at survival, 

 principally during the first year of life. It is 



estimated that from 15,000 to 30,000 surplus fe- 

 males should be harvested annually when the herd 

 is reduced to the level of maximum sustained 

 yield. At this stage, females 3 to 6 years old are 

 preferred, both because they furnish the highest 

 quality skins and because they are most easily 

 available. Males only are taken by the U.S.S.R. 

 on Robben Island and the Commander Islands, 

 but females may be taken in the future if the 

 Asian herds regain their optimum size. 



As knowledge of population dynamics accum- 

 ulates, the probability increases of successfully 

 forecasting year class survival and the resulting 

 harvest. 



When hauled out on land, fur seals are easily cut off from the sea and driven to nearby fields. Because 

 of their insulating fur, they must be driven slowly and for moderate distances to avoid heat prostration. 



^"^k 



