CONTENTS 



Page 



Introduction 1 



Methods, equipment, and personnel 1 



Methods and equipment 1 



Personnel 2 



Research in 1963 2 



Distribution of Seals by time, place, and numbers 2 



Distribution by time 2 



Distribution by area 3 



Numbers 3 



Distribution by age and sex 5 



Pairing at sea 7 



Tag recoveries 7 



Size and reproductive condition 7 



Size 7 



Pregnancy rate 8 



Reproductive condition 9 



Fetal sex ratio and uterine horn of pregnancy 12 



Anomalies 12 



Food habits 12 



Individual food items 13 



Relation of fur seals to commercial fisheries 16 



Summary 17 



Literature cited 18 



Appendix A 19 



Tables 19 



Figures 30 



TABLES 



Grouping of seals sighted during pelagic sealing research, 1958-63 5 



Age and sex by month of fur seals collected by U.S. research vessels in Bering Sea 



in 1963 6 



Male and female seals collected at sea 7 



Pelagic tag recovery rates, 1958-63 8 



Tag recoveries from fur seals collected by U.S. research vessels in Bering Sea in 



1963 8 



Pregnancy rate of seals collected by U.S. research vessels in eastern Pacific, 1958-63 10 

 Reproductive condition by month of female fur seals collected by U.S. research 



vessels in Bering Sea in 1963 11 



Fetal sex ratios and uterine horn of pregnancy 1958-63 12 



Stomach contents of fur seals from Bering Sea, 1 July to 5 September 1963 14 



Approximate course sailed bythe chartered vessels, M/V Tacoma and M/V Harmony, 

 20-28 June 1963, from the Strait of Juan de Fuca to Unimak Pass. The daylight run 

 when observations were made and the number of seals sighted each day is shown. . 



Eastern Bering Sea: The operational area of U.S. research vessels is shaded. The 

 numbers in each zone represent, from left to right, number of boat days, seals 

 seen, and seals collected from 1 July to 5 September 1963 



Comparison of lengths by age of 4,074 pregnant, 2,353 nonpregnant, and 1,528 post 

 partum female fur seals collected by U.S. research vessels in eastern Pacific, 

 1958-63 



Lengths of 4,037 fur seal fetuses plotted by 1 0-day periods, U.S. research vessel 

 collections in eastern Pacific, 1958-63 



Weights of 4,049 fur seal fetuses plotted by 10-day periods, U.S. research vessel col- 

 lections in eastern Pacific, 1958-63 



