70 



U. S. BUREAU OF FISHERIES 



The number of cows, estimated by applying an increase of 8 percent 

 to the number computed for the previous season, and the number of 

 harem bulls, determined by actual count, form the basis for calculat- 

 ing the number of animals in the average harem. 



The present average harem should give very satisfactory results. 

 Sufficient harem and idle bulls were present to take care of all females 

 arriving. In addition, there were at the end of the season large num- 

 bers of robust mature surplus bulls on the hauling grounds. Besides 

 taking care of virgin females, these mature surplus bulls act as a breed- 

 ing reserve, for they are at all times prepared to take up harem bull 

 positions, if necessary, and are able to replace harem bulls which have 

 weakened to such an extent that they are unable to hold their cows. 



Computation of breeding cows, based on annual increase of 8 percent, and of average 



harem, in 1934 



Rookery 



St. Paul Island: 



Kltovi 



Lukanin __ 



Oorbatch 



Ardiguen 



Reef 



Si vutch 



Lagoon (actual count pups) 



Tolstoi 



Zapadni 



Little Zapadni 



Zapadni Reef 



Polovina 



Polovina Cliffs 



Little Polovina 



Morjovi 



Vostochni 



Total 



St. George Island: 



North 



Staraya Artil 



Zapadni.. 



South 



East Reef __ 



East Cliffs 



Total 



Total (both islands) 



Breeding cows 



1933 



13, 837 



6,690 



35, 132 



3,323 



70, 568 



21, 594 



114 



41, 542 



39, 923 



20, 350 



706 



14,347 



7,856 



2,861 



5,143 



57, 246 



341, 232 



27, 841 

 20, 978 



2,960 

 694 



6,380 

 18, 214 



77, 067 



418, 299 



Average harem 



14, 944 



7, 225 



37, 943 



3,589 



76, 213 



23, 322 



112 



44, 865 



43,117 



21,978 



762 



15,495 



8,484 



3,090 



5,554 



61, 826 



368, 519 



30, 068 

 22, 656 



3,197 

 750 



6,890 

 19, 671 



Harem 

 bulls, 

 1934 



389 

 177 

 793 

 89 



1,493 

 400 

 3 

 997 

 866 

 478 

 62 

 372 

 317 

 103 

 309 



1,993 



8,841 



691 

 478 

 171 

 123 

 157 

 309 



83, 232 



1,929 



1934 



38.42 

 40.82 

 47.85 

 40.33 

 51.05 

 58.30 

 37.33 

 45.00 

 49.78 

 45.98 

 12.29 

 41.65 

 26.76 

 30.00 

 17.97 

 31.02 



41.68 



43.51 

 47.40 

 18.70 

 6.10 

 43.88 

 63.66 



43.15 



451, 751 



10, 770 



Increase 

 (+) or de- 

 crease (— ) 

 in 1934 from 

 1933 



36.80 

 45. 20 

 47.22 

 42.06 

 51.25 

 53.99 

 22.80 

 43.68 

 50.34 

 44.92 

 16.81 

 43.61 

 28.16 

 23.26 

 16.97 

 29.63 



40.94 



40.76 

 44.92 

 18.39 

 5.74 

 41.16 

 62.38 



41.01 



+1.62 

 -4.38 



+.63 

 -1.73 



-.20 



+4.31 



+ 14. 53 



+1.32 



-.56 

 +1.06 

 -4.52 

 -1.96 

 -1.40 

 +6.74 

 +1.00 

 +1.39 



+.74 



+2.75 

 +2.48 

 +.31 

 +.36 

 +2.72 

 + 1.28 



+2.14 



+.99 



PUPS AND COWS 



The estimated number of pups and cows was determined, as here- 

 tofore, by applying an increase of 8 percent to the numbers computed 

 for the previous season. 



The percentage of dead pups determined by actual count in 1922 

 was applied to show the number dead on each rookery. For compara- 

 tive purposes the dead pups are included in the total number of pups. 

 It is possible that the percentage of dead pups may increase slightly 



