Table 12. — Summary of seals selected and tagged 

 as yearlings in 1961 (M-series) and 1962 (N- 

 series) and recovered from the kill, Pribilof 

 Islands, Alaska, 1963 



Table 13. — Summary of Soviet tags recovered 

 from the kill, Pribilof Islands, Alaska, 

 1963 



5,000 pups were tagged in about 2-1/2 days 

 (126 man hours) 17 August to 1 September. 

 Each tag was attached to the rear edge of the 

 left fore flipper where furred skin ends and 

 bare skin begins. One-half to three-fourths 

 inch of the tip of the same flipper was sliced 

 off as a checkmark. Tag and checkmark loca- 

 tions of fur seal pups tagged since 1947 are 

 shown in appendix figure 1. 



Tagging — Yearlings 



D. G. Chapman estimated that mortality 

 from birth to age 1 could be separated from 

 mortality from birth to age 3 if 5,000 yearling 

 seals could be tagged. This assumes a high 



mortality during the first year of life and a 

 lower rate thereafter. Lack of sufficient num- 

 bers of yearlings on land, however, has pre- 

 vented the tagging of 5,000 in one season. All 

 yearling tagging has been done on St. Paul 

 Island. 



Although Wilke and Banner' collected in- 

 formation in 1941 from 41 males and 6 fe- 

 males tagged as pups in 1940, the selection 

 and tagging of yearling seals was not tried 

 until 1961. 5 That year, body weight and pelage 

 characteristics were used to identify yearlings 

 from seals of other ages. In 1962, yearlings 

 were selected on the basis of length. Only 

 females measuring 95 cm. or less and males 

 measuring 100 cm. or less were considered 

 yearlings. These maximum length limits were 

 derived from measurements of tagged 

 yearlings obtained in 1941 and 1961. 



Fifty-seven seals tagged in 1961 and 50 

 tagged in 1962 have been killed subsequently. 

 Age determination from canine teeth revealed 

 that only 24 percent of the former were 

 actually yearlings when tagged; 94 percent of 

 the latter were yearlings. Thus, body length 

 is more reliable as an indicator of age than 

 is body weight. Details on the recovery in 

 1963 of selected yearlings tagged in 1961 and 



1962 are given in appendix table 13. 



Methods . --Four to six men surrounded all 

 seals on a certain section of the rookery or 

 hauling ground, then the animals were allowed 

 to proceed toward the sea a few at a time. 

 This method permitted yearlings to be selected 

 tentatively on the basis of body size and pelage 

 coloration. Seals extracted from the group with 

 a noose attached to an 8-foot pole were re- 

 strained on the ground for measurement. Two 

 tags, one to each front flipper, were attached 

 to each seal believed to be a yearling. 

 Measurements were taken to the nearest 

 one-quarter inch and later converted to centi- 

 meters. The animals were sexed only by 

 examination of genital openings, although a 

 general difference in the width of canine 

 teeth and overall body and head shape exists 

 between the sexes at this early age. 



Re suits . --Information on selected and 

 known-age yearlings tagged in 1961, 1962, and 



1963 is summarized in table 15. Additional 

 details for those tagged in 1963 are given in 

 table 16. 



Distribution of body lengths for selected 

 and known-age yearlings is given in figures 



* Ford Wilke and A. Henry Banner. 1941. Recovery of 

 branded yearlings. Bureau of Commercial Fisheries, 

 Marine Mammal Biological Laboratory, U.S. Fish Wild- 

 life Service, Seattle, Wash. [Typed manuscript.] 



3 R. S. Peterson. 1961. Report and analysis of yearling 

 recoveries and tagging, St. Paul Island, 1961. Bureau of 

 Commercial Fisheries, Marine Mammal Biological Lab- 

 oratory, U.S. Fish Wildlife Service, Seattle, Wash. [Typed 

 manuscript.] 



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