Table Al. — Measurements of territoriaiy and nonterritoriali/ male seals of selected ages,^ 



St. Paul Island 



[Numbers of seals in parentheses] 



V Killed in 1965. 



2/ Killed in 1967. 



3/ Seals in ages 9 to 13 were selected because most measurements were made for these animals. 



4/ Seals were neither measured nor weighed in July 1965. 



SUMMARY 



Field investigations on the Pribilof Islands 

 in 1968 were conducted for continuing studies 

 of the fur seal population and the level at which 

 it will produce a maximum sustained yield. 



A kill of 44,292 males in ages 2 to 6 included 

 35,292 from St. Paul Island and 9,000 from 

 St. George Island. Ages were not determined 

 for 1,333 young males. 



A kill of 13,297 females in ages 2 to 24 in- 

 cluded 10,544 from St. Paul Island and 2,753 

 from St. George Island. Ages were not de- 

 termined for 38 females. 



The number of dead pups counted was 26,563 

 on St, Paul Island and 4,875 on St. George 

 Island. 



Causes of death among 379 pups that died on 

 three study areas by 15 August were mal- 

 nutrition (48 percent), hookworm disease (17 

 percent), trauma (6 percent), nnicrobial in- 

 fections (5 percent), perinatal complex (5 per- 

 cent), miscellaneous (2 percent), and unknown 



George Island, 



1966 to 1968 



and 106 on St, 



(3 percent). Fourteen percent of the pups were 

 unsuitable for examination. 



The number of dead males counted was 

 587 from 1965 to 1968 on St, Paul Island and 

 114 from 1966 to 1968 on St, 

 Dead fennales counted from 

 were 490 on St, Paul Island 

 George Island. 



An estimated 7,924 harem and 4,383 idle 

 males were on the Pribilof Islands in 1968, 



Pregnancy rates of females age 8 and older 

 taken from hauling grounds were 42 percent 

 for 1,058 killed in 1968 and 42 percent for 

 198 taken in 1958, Pregnancy rates of females 

 taken from rookeries were 99 percent for 

 84 killed in 1956 and 100 percent for 221 taken 

 in 1957, 



Average weights of 9.6 kg. for males and 8.3 

 kg, for females on St. Paul Island were within 

 0.1 kg. of the average weights of pups weighed 

 there from 1957 to 1968. Untagged males on 



31 



