Table 8. — Reproductive condition of female seals 

 sampled from the kill, by age, St. Paul Island: 

 1-15 August 1967 



Reproductive 

 condition 



7 and 

 older 



Nonpost partum 2 104 192 160 103 373 934 

 ( number) 



pregnancy rates (table 8) are not representa- 

 tive of the total population of females because 

 the animals killed were taken from hauling 

 grounds. As a group, females on hauling 

 grounds in 1967 had a pregnancy rate of about 

 one-third that of females on the rookeries in 

 other years, and about half that of females col- 

 lected at sea during pelagic research. 



WEIGHTS OF PUPS 



Data collected annually since 1957 on St. 

 Paul Island to determine if the body weight of 

 unmarked and untagged pups is related to the 

 kill of males at age 3 have been inconclusive. 

 The data for 1967 are discussed in the section 

 on forecasts. In addition to the data on survival, 



information on weights shows that tagging, 

 checkmarking, or handling (individually or 

 combined) retards the growth of pups. 



In 1967 we tested the variances and means 

 (table 9) of the weights of untagged and un- 

 marked pups from four rookeries. The vari- 

 ances and means for sexes and rookeries com- 

 bined were significantly different (P<0.001). 

 The variances were still significantly different 

 when the sexes were tested separately 

 (F<0.05). A test of the means with hetero- 

 geneous variances indicated that the mean 

 weights differed significantly between rooker- 

 ies for each sex (P<0.001). 



Table 9. — Variances and means of weights of 

 pups, St. Paul Island, 31 August 1967 



Females 



Zapadni Reef 100 



Polovina 100 



Morjovi 100 



Reef 100 



2.6197 8.945 



3.1156 8.945 



2.3759 9.230 



1.6276 8.965 



MARKING 



Fur seals of various ages have been given 

 permanent marks to provide data for estimating 

 the size of the population and for studying age 

 and growth, mortality, distribution at sea, 

 homing tendency, and commercial value of the 

 skins. Application and recovery of marks are 

 discussed in this section. 



APPLICATION OF MARKS 



Monel cattle-ear tags have been used on the 

 Pribilof Islands to mark fur seal pups since 

 1941 (table A- 17) and older seals since 1961 

 (table A- 18). Cryogenic branding is being tested 

 as a way to permanently mark seals without 

 injuring them. 



Marking in 1967 



We marked pups of both sexes, yearling 

 males, and 2- to 4-year-old males with Monel 

 cattle-ear tags on the Pribilof Islands in 1967. 



Pups .- -Single T-series tags were attached 

 to 9,980 pups on St. Paul Island (table A-19) 

 and to 2,492 pups on St. George Island (table 

 A-20). We attached the tags to the rear edge 

 of the right front flipper at the hairline and 

 removed the tip of the same flipper as a check- 

 mark (fig. 8). Seals that lose their tags can be 

 identified as to the year of birth by this check- 

 mark. 



Yearling male seals . --Males < 98 cm. long 

 (38 inches) or males marked or tagged as pups 

 were double tagged or given an additional tag 

 (lT-series) during late September and early 

 October. A total of 835 males tagged as 

 yearlings in 1967 (table A-21) included 48 that 

 had been tagged or marked as pups in 1966 

 (table A-22). The mean length of 787 males 

 selected as yearlings was 93.9 cm. (36.9 in- 

 ches) and that of 48 males known to be year- 

 lings was 92.6 cm. (36.4 inches). Nearly three- 

 fourths of the males tagged were hauled out at 

 English Bay. No females were tagged as 

 yearlings. 



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