VI 



CONTENTS 



Page 



Limiting factors 249 



Natural mortality 250 



Predation 278 



Environmental pollution 281 



Poaching 281 



Summary 282 



In captivity 284 



Capture 284 



Environmental needs of captives 287 



Food and feeding of captives 293 



Daily cycle of activity 303 



Causes of death in captivity 309 



Drug use 311 



Transportation of captives 315 



Transplant attempts 319 



Management 323 



References 326 



Appendix 1 — Field studies of sea otters, 1954-66 337 



Appendix 2 — Tabular summary of sea otters 



studied from 1955 through 1965 341 



ILLUSTRATIONS 



Figure 



1. Pelage appearance shortly after a sea otter 



emerged from the water and shook himself 7 



2. Front feet of the sea otter 8 



3. The external ear of the sea otter resembles the 



ear of an otariid seal 9 



4. Dorsal and ventral views of a newly 



bom female sea otter 10 



5. Adult male river otter 12 



6. A small adult female sea otter 13 



7. Eight sea otters asleep in a kelp bed at 



Amchitka Island 14 



8. Plantar surface of the left hind foot of an adult 



male sea otter 15 



9. The skeleton of an adult female sea otter to 



show the general location and shape of the bones 16 



10. The baculum of an adult male sea otter 17 



11. Adult male sea otter 17 



12. Adult female sea otter eating the head of a large 



codfish , 18 



13. At birth the claws are white and curved 21 



14. Hair from the mid-back of adult male sea otter 32 



15. Plastic impression of pelage sheared near skin 



surface from midback of adult male sea otter 33 



16. Horizontal section through skin near surface, 



midback, adult male sea otter 34 ! 



17. Sheared surface showing skin and distribution of 



pores from which hair bundles emerge 35 



