Our Livint; Resources — Alaska 



353 



Chukchi Sea. there is a pressing need tor devel- 

 opment of new methods for determining num- 

 bers and trends. This need appears more urgent 

 in view of the hkehhood that the ban on polar 

 bear hunting in Russia, in effect since 1956. will 

 be lifted. The bounds of optimum sustainable 

 population levels are not known in the Beaufort 

 or Chukchi seas, and interactions between polar 

 bears and their prey and polar bears and sea ice. 

 which establish these levels, are not understood. 

 If managers are to keep polar bear numbers at 

 optimum sustainable population levels in the 

 face of increased harvests and other local and 

 global perturbations, they will need more accu- 

 rate and precise population estimates and an 

 understanding of the ecosystem forces that limit 

 polar bear population size. 



References 



Amstrup. S.C. I. Stirling, and J.W. Lentfer. 1986. Past and 

 present status of polar bears in Alaska. Wildlife Society 

 Bull. 14(3):241-2.';4. 



Calvert. W.. and I. Stirling. 1990. Interactions between polar 

 bears and overwintering walruses in the central Canadian 

 High Arctic. International Conference of Bear 

 Researchers and Managers 8:351-.3.'i6. 



Caughley. G. 1977. Analysis of vertebrate populations. John 

 Wiley and Sons, New York. 234 pp. 



Fay. F.H. 1982. Ecology and biology of the Pacific walrus. 

 Odobenus nismanis Jivergens Illiger. North American 

 Fauna 74:1-279. 



Garner. G.W., S.T. Knick. and D.C. Douglas. 199(1. 

 Seasonal movements of adult female polar bears in the 

 Bering and Chukchi seas. International Conference of 

 Bear Researchers and Managers 8:219-226. 



Hanna. G.D. 1920. Mammals of the St. Matthew Islands. 

 Bering Sea. Journal of Mammalogy 1:118-122. 



Harington, C.R. 1968. Denning habits of the polar bear 

 [Ursus marilimus). Canadian Wildlife Service Rep. 

 Series 5. 33 pp. 



Hensel. R.J.. and F.E. Sorensen. 1980. Age determination of 

 live polar bears. International Conference of Bear 

 Researchers and Managers 3:93-100. 



Kiliaan. H.P.L.. and 1. Stirling. 1978. Observations on over- 

 wintering walruses in the eastern Canadian High Arctic. 

 Journal of Mammalogy 59:197-200. 



Leffingwell. E. 1919. The Canning River region, northern 

 Alaska. U.S. Geological Survev Professional Paper 1(19. 

 247 pp. 



Lentfer. J.W. 1983. .Alaskan polar bear movements from 

 mark and recovery. Arctic 36:282-288. 



Leslie. PH. 1945. On the use of matrices in certain popula- 

 tion mathematics. Biometrika 33:183-212. 



Leslie. PH. 1948. Some further notes on the use of matrices 

 in population mathematics. Biometrika 35:213-245. 



Lono. O. 1970. The polar bear ( Ursiis niaririiniis PhippsI in 

 the Svalbard area. Norsk Polarinstitutt Skrifter 149. 103 

 pp. 



Mowat. F. 1984. Sea of slaughter Atlantic Monthly Press. 

 Boston. 322 pp. 



Pollock. K.H.. J.D. Nichols. C. Brownie, and J.E. Hines. 

 1990. Statistical inference for capture-recapture experi- 

 ments. Wildlife Monographs 107:1-97. 



Pollock. K.H.. S.R. Winterstein. CM. Bunck. and PD. 

 Curtis. 1989. Survival analysis in telemetry studies: the 

 staggered entry design. Journal of Wildlife Management 

 53(1):7-15. 



Seber, G.A.F. 1973. The estimation of animal abundance. 

 Hafner Press. New York. 506 pp. 



Smith. T.G. 1980. Polar bear pred,ation of ringed and beard- 

 ed seals in the land-fast ice habitat. Canadian Journal of 

 Zoology 58(12 1:2201-2209. 



Smith. T.G.. and I. Stirhng. 1975. The breeding habitat of 

 the ringed seal (Phoca bispida). The birth lair and asso- 

 ciated structures. Canadian Journal of Zoology 53:1297- 

 1305. 



Stirling. I.. D. Andriashek. R Latour, and W. Calvert. 1975. 

 Distribution and abundance of polar bears in the eastern 

 Beaufort Sea. Canadian Wildlife Service Tech. Rep. 2. 59 

 pp. 



Stirling. I., and W.R. Archibald. 1977. Aspects of predation 

 of seals by polar bears. Journal of the Fisheries Research 

 Board of Canada 34: 1 126-1 129. 



Stirling. I., and A.E. Derocher 1990. Factors affecting the 

 evolution and behavioral ecology of the modem bears. 

 International Conference of Bear Researchers and 

 Managers 8:189-204. 



Stirling. I., and A. Derocher. 1993. Possible impacts of cli- 

 matic warming on polar bears. Arctic 46:240-245. 



Uspenski. S.M.. and S.E. Belikov. 1991 . Polar bear popula- 

 tions in the Soviet Arctic: current state, studies, and man- 

 agement. Pages 93-95 in S.C. Amstrup and O. Wiig. eds. 

 Polar bears. International Union for the Conservation of 

 Nature and Natural Resources. Species Survival 

 Committee Occasional Paper 7. 



Radio-collared polar bear ( Ursus 

 marilimus) female and 3-month- 

 old cub. 



For further information: 



Steven C. Amstrup 



National Biological Service 



Alaska Science Center 



1011 E. Tudor Rd. 

 Anchorage. AK 99508 



About 250 years ago sea otters (Enhydru 

 liitris) were distributed continuously from 

 central Baja California, north and west along 

 the Pacific Rim to Kamchatka Peninsula in 

 Russia, and south along the Kuril Islands to 

 northern Japan (Kenyon 1969: Fig. la). Several 

 hundred thousand sea otters may have occurred 

 in the north Pacific region when commercial 

 hunting began in the 1 8th century ( Riedman and 

 Estes r99(i'). 



At least two attributes of the sea otter have 

 influenced humans likely for as long as they 

 have resided together along the coast of the 

 north Pacific Ocean. First, sea otters rely on a 

 dense fur, among the finest in the world, for 

 insulation in the cold waters of the Pacific 

 Ocean. The demand for sea otter fur led to their 

 near extinction in the 1 9th century. The fur har- 



vest, begun about 1740 and halted by interna- 

 tional treaty in 1911, left surviving colonies, 

 each likely numbering less than a few hundred 

 animals, in California, south-central Alaska, 

 and the Aleutian, Medny, and Kuril Islands (Fig. 

 la). These individuals provided the nucleus for 

 the recovery of the species. Today more than 

 100,000 sea otters occur throughout about 75% 

 of their original range (Fig. lb). Immigration 

 has resulted in near-complete occupation of the 

 Aleutian and Kuril archipelagos and the Alaska 

 Peninsula. Successful translocations have 

 resulted in viable populations in southeast 

 Alaska, Washington, and British Columbia. 

 Large amounts of unoccupied habitat remain 

 along the coasts of Russia, Canada, the United 

 States, and Mexico. 



The second potential source of conflict 



Sea Otters in 

 the North 

 Pacific Ocean 



by 



James L. Bodkin 



Ronald J. Jameson 



James A. Estes 



National Biological Service 



