338 



U. S. BUREAU OF FISHERIES 



COMPLETE COMPUTATION 



Following is a siimmaiy of the method used for computing the 

 number of animals in the Pribilof Islands fur-seal herd in 1929, 

 together with a recapitidation of the herd by classes. It will be noted 

 that the increase in the total number of seals over 1928 was 100,014, 

 or 11.48 per cent. The increase in 1928 over 1927 was 62,643, or 7.74 

 per cent. 



Complete comjmtation of fur seals, Pribilof Islands, as of August 10, 1929 



Class 



Pups, estimated 



Breeding cows, 3 years old and over, by inference- 

 Harem bulls, counted 



Idle bulls, counted 



Yearlings, male and female, estimated: 

 Females born in 1928 



Natural mortality, 40 per cent 



Yearling females, Aug. 10, 1929. 



Males born in 1928 



Natural mortality, 40 per cent. 



Yearling males beginning 1929- 

 Yearling males killed 1929 



Yearling males, .\ug. 10, 1929- 



2- year-olds, male and female, estimated: 



Yearling females, Aug. 10, 1928 



Adjustment to decrease mortality rate of yearlings from 45 per cent 

 to 40 per cent -- 



Corrected total for Aug. 10, 1928. 

 Natural mortality, 15 per cent... 



2-year-old females, Aug. 10, 1929- 



Yearling males, Aug. 10, 1928. 



Adjustment to decrease mortality rate of yearlings from 50 per cent 

 to 40 per cent 



Corrected total for .\ug. 10, 1928 



Yearling males killed fall 1928.... 



Yearling males end of 1928.. 



Natural mortality, 17.5 per cent - -- 



2-year-olds beginning 1929 



2-year-olds killed 1929_- --. 



2-year-old males, Aug. 10, 1929 



3-year-old males, estimated: 



2-year-old males, Aug. 10, 1928 



Adjustment to decrease mortality rate of yearlings from 50 per cent 

 to 40 per cent , 



Corrected total for Aug. 10, 1928... 

 2-year-old males killed fall of 1928. 



2-year-old males end of 1928 



Natural mortality, 12.5 percent... 



3-year-old males beginning 1929... 

 3-year-old males killed 1929 



3-year-old males, Aug. 10, 1929.. 



4-year-old males, estimated: 



3-year-old males Aug. 10, 1928 



3-year-old males killed, fall 1928... 



3-year-old males end of 1928 



Natural mortality, 10 per cent 



4-year-old males beginning 1929... 

 4-year-old males killed 1929. , 



4-year-old males, Aug. 10, 1929.. 



St. Paul 

 Island 



St. George 

 Island 



250, 844 



250, 844 



5,998 



1,339 



116,137 

 46, 455 



69, 682 



116, 137 

 46, 455 



69, 682 

 37 



69, 645 



59, 126 

 5,375 



64,501 

 9, 675 



54,826 



53, 721 



10, 750 



64,471 

 5 



64, 466 

 11,281 



53, 185 

 781 



52, 404 



40, 000 

 8,215 



48,215 

 46 



48, 169 

 6,021 



42, 148 

 31,635 



(') 



442 



56, 647 



56, 647 



1,189 



294 



26, 225 

 10,490 



26, 226 

 10, 490 



15, 736 



15, 736 



13, 355 

 1,214 



14, 569 

 2,185 



12, 140 

 2,429 



14, 569 



14, 569 

 2,550 



12,019 

 69 



11,950 



9,087 

 1,855 



10, 942 

 5 



10, 937 

 1,367 



9,570 

 6,444 



(') 



295 



1 As it was not possible to allocate to each island the 3, 4, or 5 year old males in 1928, it is not possible 

 to do this in respect to the 4, 5, or 6 year old males in 1929. • 



