82 



U. S. BUREAU OF FISHERIES. 



Harem and idle bulls and percentage of idle to harem bulls compared to average harem, 

 Pribilof Islands, 1921 — Continued. 



The above table shows a decrease of number of harem bulls, a 

 greater decrease of the number of idle bulls, and an increase in the 

 average harem. The average harem for the entire herd is 45.19, which 

 is as near the ideal size as can be expected. The idle bulls have de- 

 creased in number, until the percentage of idle to harem bulls is 

 lower than it has been since 1914. The idle bulls not only form a 

 reserve from which harem bulls are drawn, but they also are impor- 

 tant as the class which serves most of the virgin cows. It is advisable 

 to maintain this class at a certain proportion to the harem bulls for 

 the latter reason. Normally there are about one-fifth as many virgin 

 cows as there are breeding cows. The most desirable proportion is 

 one idle bull to four or five harem bulls. ^ The failure oi this class to 

 appear in larger numbers points to the possibility that the males suffer 

 a greater loss of life at sea than do the females. 



AVERAGE HAREM. 



Average harem in 1921 for all fur-seal roolceries on Pribilof Islands. 



Rookery. 



ST PAUL LSLAND 



Kitovi 



Lukanin 



Gorbatch 



Ardiguen 



Reef 



Sivu tch 



Lagoon 



Tolstoi 



Zapadni 



Little Zapadni 



Zapadni Reo! 



Polovina 



Polovina ClilTs 



Little Polovina , 



Morjovi , 



Vostorhni , 



Total 



Total (oi rookeries counted 



1 E.«timate. 



Breeding 

 cows. 



4,353 



2, 93S 



10, 900 



1,088 



24,638 



8,854 



287 



16, 708 



10,830 



10, a37 



502 



6, 071 



2,7S5 



1,676 



2,994 



40, 195 



149,865 



Harem 

 bulls. 



12, r.39 



161 

 100 

 232 



32 

 521 

 190 



16 

 328 

 380 

 213 



23 

 161 

 111 



48 

 104 

 823 



3,443 



Average 



harem, 



1921. 



127.04 

 1 29. 33 

 1 47. 02 

 134.00 

 1 47. 29 

 1 46. 00 

 2 17. 94 

 1 47. 89 

 144.29 



1 47. 12 



2 21.83 

 237.71 

 2 25. 09 

 1 34. 92 

 2 28. 79 

 148.84 



43. .53 



30.40 



Average 



harem, 



1920. 



1 28. 52 

 130.86 

 1 40. ,52 

 129.50 

 1 44. 77 



1 44. 08 



2 24. 36 

 1 42. 37 

 1 38. 77 



1 42. 97 



2 19.00 

 2 33. 93 

 ■ 29. 92 

 134.92 

 '' 30. 27 

 1 45. 32 



40.45 



30.82 



' Pups counted. 



f" Osgood, Wilfred H.; Edward .\. Preble; and George H. Parker: The Fur Seals and Other Life of the 

 Pribilof Islands, Alaska, in 1914. Bulletin, U. S. Bureau of Fisheries, VoL XXXIV, 1914, p. 55. Wash- 

 ington, 1915. 



