162 



U. S. BUREAU OF FISHERIES 



X umber of harem and idle bulls, relation of idle bulls to harem bulls, expressed in 

 percentage, and average harem, 1925 



1 Estimated. 



The bull count in 1925, as indicated in the above table, showed 

 that there was a large decrease in harem bulls on the rookeries of the 

 northeast side of St. Paul Island. In 1924, Vostochni had 856 harem 

 bulls but in 1925 only 675, a decrease of 181 harems. Virtually all 

 of the rookeries on the south side of St. Paul as well as those of St. 

 George showed an increase in harem bulls. The number of harems 

 on Reef rookery, St. Paul Island, increased from 429 in 1924 to 507 

 in 1925. North rookery, on St. George Island, increased in size from 

 127 harems in 1924 to 139 in 1925. On St. Paul Island there were 

 3,103 harem bulls and on St. George Island 423, a total of 3,526 for 

 both islands. In 1924 the total was 3,516. 



The number of idle bulls on both islands decreased from 390 in 1924 

 to 31 1 in 1925. The number of idle bulls approximately equaled 1 1 .09 

 per cent of the number of harem bulls in 1924, and approximately 8.82 

 per cent in 1925. 



Six dead bulls were found. No bulls that had been branded as 

 pups in 1912 were seen on either island. 



AVERAGE HAREM 



As a pup count was not made in 1925, the average harem was used 

 as the basis for computing the number of cows and pups. A com- 

 plete pup count was made in 1916 and another in 1922. From the 

 average harems in these two years, an average annual increase in 



