and continued in 1964 to determine the relative 

 number of known-age yearling seals on land 

 in late September and early October. If the 

 number of yearlings counted on land during 

 the sampling period is related to the return 

 of the age class 2 years later, yearling sur- 

 veys will be useful as a method for predicting 

 the kill of 3-year-old males. An additional 3 

 or 4 years of data are necessary, however, 

 before it can be determined if such a rela- 

 tionship exists. 



The results of the yearling surveys in 1964 

 are given in table 15. Methods and survey 

 areas used have been described previously 

 (Roppel, Johnson, and Chapman, 1963). Among 

 known-age yearlings captured during the sur- 

 veys in 1963 and 1964 and during yearling 

 tagging in 1961, 1962, and 1963, males have 

 outnumbered females by as much as 15 to 1. 



Table 16. --Dead-pup counts, Pribilof 

 Islands, Alaska, 1964 



NEP 

 POL 

 GOR 

 REEF 

 KIT 

 TOL 

 ZR 



L. ZAP 

 ZAP 

 Total 



1 

 6 

 3 

 3 

 23 



Seals tagged as pups in 1963. 



Mortality 



Pup mortal 

 percent of the 

 and by 52 per 

 1964 count of 

 the beginning 

 data for both 

 rookery, and d 

 are presented 



ity in 1964 decreased by 34 

 1963 count on St. Paul Island 

 cent on St. George Island. The 

 dead pups was the lowest since 

 of complete counts in 1953. The 

 islands are given in table 16 by 

 ead-pup counts made since 1941 

 in appendix table 17. 



Population Estimates 



Estimates of the pup population are cur- 

 rently derived from three sources: (1) The 

 tag recoveries and tag loss identifications in 

 the kill; (2) the ratio of marked to unmarked 

 in samples of live pups; and (3) total counts of 

 live pups on three rookeries and a portion of 



Rookery 



St. Paul Island 



Northeast Point 

 Morjovi 

 Vostochini 



Polovina 



Little Polovina 

 Polovina Cliffs 

 Polovina 



Reef 



Ardiguen 

 Go r batch 

 Reef 



Kitovi 



Lukanin 



Tolstoi 



Zapadni 



Little Zapadni 

 Zapadni Reef 

 Zapadni 



Counted total 

 5 percent addition 

 Estimated total 



Dead pups 



22,651 



a fourth. In previous years the tag-lost to 

 tagged ratio on St. George Island was changed 

 to correspond to the ratio observed onSt. Paul 

 Island if there was an appreciable difference 

 in the ratios observed on the two islands. This 

 procedure was not used this year. 



In 1964, for the first time, recoveries of 

 tags from males tagged as yearlings were 

 sufficiently numerous to form a basis for 



15 



