ALASKA FISHERY AND FUR-SEAL INDUSTRIES, 1931 



91 



Number of harem and idle bulls, ap-proximale ratio of idle bulls to harem bullsy 



and average harem, 1931 



AVERAGE HABEM 



The average harem has been determined through actual count of 

 bulls and on the basis of an increase of 8 per cent over the previous 

 year for cows. The estimated average harem for St. Paul Island is 

 38.71, and for St. George Island 39.42. The average harem for the 

 two islands is 38.84; a decrease of 1.11 from the previous year. This 

 brings the average harem down to a point which by some is consid- 

 ered practically ideal, although it would possibly be to the best 

 interests of the herd to bring down the average harem somewhat 

 lower. 



It has been clearly demonstrated that the herd will increase much 

 faster if there is a larger number of harem, idle, and surplus bulls, 

 than if barely sufficient males for harem requirements are permitted 

 to mature. In regard to the average harem, it is essential to consider 

 both islands as a whole, for it is not possible to make an actual count 

 of cows. As various conditions continually cause temporary, or per- 

 manent, increases or decreases in the number of cows and bulls on any 

 given rookery, the present method of applying the same average rate 

 of increase for cows to each rookery obviously results in incorrect 

 figures for each particular rookery. It is impossible accurately to 

 correct these errors, inasmuch as a pup count is impractical. The 

 average harem for each island, and more particularly the average 

 harem for the two islands as a whole, however, will be fairly correct — 

 at least sufficiently so for all practical requirements. 



