Females 



1. Population estimates through the 1959 

 year class indicate that the female herd ex- 

 ceeds the level necessary for optimum pro- 

 duction. However, scarcity of females on the 

 hauling grounds in 1961 and 1962 suggests 

 that the combined effects of natural mortality 

 and commercial killing have achieved a sub- 

 stantial reduction. As many as 47,413 females 

 were easily taken by 20 August~(1957); Sep- 

 tember reduction kills of from 9 to 10 days 

 duration were necessary in 1961 and 1962 to 

 achieve quotas of 43,750. The September kills 

 were in addition to kills ending 15 August in 

 1961 and 24 August in 1962. 



2. From 2 July to 5 August and from 13 

 to 17 and 20 to 24 August, 28,121 females 

 were killed on the Pribilof Islands in 1962; 

 an additional 15,639 females were killed in 

 September on St. Paul Island. 



3. Selective killing for young females in 

 August and old females in September was 

 reflected in the age composition of animals 

 taken on St. Paul Island. In August, 3-, 4-, 

 and 5-year-old females accounted for 55 per- 

 cent of the kill; in September these ages 

 made up only 24 percent. 



4. A progressive increase during the Sep- 

 tember kill of the proportion of post partum 

 females was attributed to a gradual shift 

 from killing females from the hauling grounds 

 to killing animals taken from rookery fringes 

 or from rookeries. 



Tag Recoveries and Tagging 



1. Totals of 3,718 tagged seals and 2,417 

 with checkmarks only were recovered. An ad- 

 ditional 20 tags attached to fur seals by Soviet 

 investigators were recovered on the Pribilof 

 Islands. 



2. Fifty thousand seal pups were tagged on 

 the right fore flipper with 0-series tags and 

 a "V" notch checkmark was cut into the leading 

 edge near the tip of each tagged flipper. 



3. A total of 839 seals was tagged as year- 

 lings in 1962; 128 that had been tagged as 

 pups in 1961 were each given an additional 

 tag. Sex ratios for selected and known-age 

 yearlings were 171c?(?::100$? and 325d'd::100 V$ 



respectively. Distribution of body lengths for 

 selected and known-age males and females 

 were similar. Twenty-three animals tagged 

 as yearlings in 1961 were recovered from the 

 kill in 1962; age determination from canine 

 teeth revealed thatonly one was a yearling when 

 tagged. 



Mortality 



The 1962 pup mortality decreased to 53,748 

 from 71,011 in 1961. 



Seal-pup Weights 



Data collected through 1961 showed that the 

 mean weight of tagged pups was less than that 

 of untagged pups. Three weighings, a month 

 apart, the first 1 week after tagging, were 

 carried out in 1962 to assess the permanency 

 of lighter weight among tagged pups. The data 

 showed that untagged pups were significantly 

 heavier than tagged pups in early September. 

 Untagged pups were still heavier than tagged 

 pups in October but the difference was sig- 

 nificant only for males early in the month. 

 The weight of pups increased by 3.5-4.0 kilo- 

 grams from early September to late October. 

 The rate of gain tended to be greater in Sep- 

 tember than in October. 



Related Studies 



The current phase of hookworm research 

 was completed with the 1962 field season and 

 a subsequent report by the contract investi- 

 gator. It now seems apparent that all fur 

 seals harbor a free-living stage of the para- 

 site in their belly blubber, that the adult 

 seals probably carry the tissue Infection 

 throughout their lives, and that pups receive 

 intestinal infections by ingestion with milk. 



ACKNOWLEDGMENTS 



The research staff acknowledges with ap- 

 preciation the cooperation given to them by 

 C. Howard Baltzo, Program Director; Roy D, 

 Hurd, St. Paul Island Manager; A. R. Williams, 

 St. George Island Manager; and Stuart Davey, 

 Wildlife Management Biologist, Pribilof 

 Islands. 



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