Figure 9. — V-notch mark applied to pups and used sub- 

 sequently to identify age when the seal has lost its tag, 

 or was V-notched only. This mark was photographed 

 soon after it was made with a veterinary ear-notching 

 instrument. 



UJ 

 S 80 



- KNOWN-AGE MALES 

 ■SELECTED MALES 



560 370 SBO 



LENGTH (INCHES) 



Figure 11, — Body lengths of known-age yearling males 

 and males selected as yearlings on the basis of body 

 length, St. Paul Island, 1965. 



^'ift«>^ 



Figure 10. — V-notch checkmarks applied to pups in 1962 

 with veterinary ear-notching instruments and recovered 

 from tagged 3-year-old males in 1965. Of 279 check- 

 marks examined, 95 percent were similar to those in 

 the top row, and 5 percent resembled those in the bottom 

 row. Examination of thousands of seals has shown that 

 the marks in the top row cannot be confused with acces- 

 sory or naturally occurring marks. The marks in the 

 bottom row would not have been recognized if the seals 

 had not been tagged; these marks are assumed to be 

 checkmarks. 



Pup Weights 



Seal pups have been weighed on St. Paul 

 Island annually about 1 September since 1957 

 to determine if body weight of untagged pups 

 in autumn is related to survival. A consistent 

 relation would be useful in predicting the 

 returns (kill) from a year class. The data 

 obtained to date are discussed in appendix A. 



The weighing program has also provided 

 information on the effects of tagging and mark- 

 ing pups. Each year since 1957, untagged and 

 unmarked pups have been heavier than tagged 

 and marked pups 1 or 2 weeks after tagging 

 (app. table 21). The mean weights of untagged 

 and unmarked males and females in 1965 were 

 1.14 and 1.04 kg. more than tagged and marked 

 males and females. This difference in weight 

 may cause tagged and marked pups to die at 

 a greater rate than untagged and unmarked 

 pups during their first winter at sea. If true, 

 then subsequent estimates of the population 

 based on recoveries of tags and marked seals 

 are inflated. 



The tip of the big toe or first digit (fig. 10) 

 on the right hind flipper of each of 10,080 

 pups was removed as part of the pup tagging 



Table 9. — Sunmary of data from tagging of yearlings, St. Paul Island, 1965 



Animals bearing tags or checkmarks applied In year of birth. 



Length was taken to nearest half inch, then converted to centimeters. 



14 



