Seal-pup Weights 



Since 1957, seal pups have been weighed 

 annually on St. Paul Island about 1 September. 

 The primary purpose was to determine if the 

 mean weight of pups is related to the return 

 of the year class 3 and 4 years later. There 

 are as yet not enough data to determine if the 

 relation between weight as pups and return of 

 the year class will be of value for predicting 

 returns (table 25). Preliminary studies are 

 not encouraging. 



.1/ 



As in previous years (Roppel, Johnson, and 

 Chapman, 1 965) the weighing program produced 

 important secondary information on differences 

 in the mean weights of tagged and untagged 

 pups (tables 26 and 27). In 1964, tagged males 

 and females averaged 1.10 and 0.92 kg. less 

 than untagged males and females. This weight 

 difference is 12 percent of the mean weights 

 of untagged males and females. 



Appendix table 18 lists the tag numbers 

 and weights of tagged pups by rookery and by 

 sex. 



Table 25. --Mean weights— of untagged pups and male returns, 

 Pribilof Islands, Alaska, year classes 1957-60 



— Numbers in parentheses are the number of pups in 

 each sample. 



1/ 

 Table 26. --Mean weights of seal pups,— St. Paul Island, year 



class 1964 



Rooker\ 



Males 



Untagged 



Tagged 



Females 



Untagged Tagged 



K£l 



Kfii 



KiL 



KJL 



NEP 



REEF 



ZAP 



POL 



— Numbers in parentheses are the number of pups in 

 each sample. 



22 



