CONTENTS 



Page 



Introduction 2 



Part I. Fur seal investigations, Pribilof Islands, Alaska 2 



Age classification and number of seals killed, by sex 4 



Males 4 



Females 6 



Survey data 6 



Mortality 6 



Counts of living adult males 12 



Reproductive condition of females 13 



Weights of pups 13 



Marking 14 



Application 14 



Recoveries 17 



Population estimates 21 



Number of pups born 21 



Number of male yearlings 24 



Forecast of the kill of males in 1967 24 



Forecast of the kill of 4-year-old males on St, Paul Island 25 



Forecast of the kill of 3-year-old males on St. Paul Island 27 



Forecast of the total kill on the Pribilof Islands 29 



Special studies 31 



Age composition, measurements, and mortality of territorial male fur seals ... 31 



Implantation of blastocysts in fur seals 36 



Errors in determining ages of fur seals from canine teeth 38 



Comparison of ages assigned to fur seals by Japanese and U.S. biologists 41 



Drug immobilization of fur seals 42 



Nutrition of pups 43 



Analysis of fur seal milk 46 



Cryogenic marking 47 



Summary 50 



Acknowledgments 51 



Glossary 52 



Part II. Pelagic fur seal investigations, 1966 53 



Equipment, methods, and personnel 53 



Research in 1966 54 



Distribution off California 54 



Relative abundance of seals and size of groups 54 



Distribution by age and sex 56 



Tag recoveries 57 



Size 60 



Reproduction 60 



Attached organisms (commensals) 61 



Food 61 



Relation of fur seals to commercial fisheries 66 



Summary 67 



Literature cited 67 



Appendix A 70 



Appendix B 97 



Appendix C 98 



