RANGE-WIDE STATUS REVIEW OF THE POLAR BEAR (Ursus maritimus) Prepared and Edited By Scott Schliebe, Thomas Evans, Kurt Johnson, Michael Roy, Susanne Miller, Charles Hamilton, Rosa Meehan, Sonja Jahrsdoerfer 1 U.S. Fish and Wildlife Service 1011 E. Tudor Road, Anchorage, Alaska December 21, 2006 1 I. INTRODUCTION TO POLAR BEAR STATUS REVIEW ..........................................................................5 II. POPULATION ECOLOGY AND CHARACTERISTICS OF TAXON.......................................................6 A. TAXONOMY ..........................................................................................................................................6 B. GENERAL DESCRIPTION.......................................................................................................................7 C. ECOLOGICAL ADAPTATIONS ...............................................................................................................7 D. DISTRIBUTION....................................................................................................................................10 E. MOVEMENTS ......................................................................................................................................12 F. FEEDING HABITS................................................................................................................................16 G. REPRODUCTION .................................................................................................................................17 1. Litter size and production rate..................................................................................................................19 2. Reproductive maturity and senescence. ...................................................................................................20 H. SURVIVAL ...........................................................................................................................................20 III. HABITAT CHARACTERISTICS.............................................................................................................22 A. SEA ICE ............................................................................................................................................23 1. Polar bear-ice relationships - general......................................................................................................24 2. Polar bear – ice relations - specific ..........................................................................................................26 3. Variations in sea ice and polar bear.........................................................................................................29 B. MATERNAL DENNING HABITAT ........................................................................................................29 TH IV. POPULATION STATUS AND TREND (EXCERPTED FROM THE PBSG 14 WORKING GROUP PROCEEDINGS) .......................................................................................................................................34 A. DISTINCT POPULATION SEGMENTS...................................................................................................34 B. STATUS AND DISTRIBUTION ...............................................................................................................34 C. POPULATION SUMMARY ....................................................................................................................37 1. East Greenland (EG) ................................................................................................................................38 2. Barents Sea (BS).......................................................................................................................................39 3. Kara Sea (KS) ...........................................................................................................................................40 4. Laptev Sea (LV) ........................................................................................................................................41 5. Chukchi Sea (CS)......................................................................................................................................41 6. Southern Beaufort Sea (SB).....................................................................................................................43 7. Northern Beaufort Sea (NB) ....................................................................................................................45 8. Viscount Melville Sound (VM).................................................................................................................46 9. Norwegian Bay (NW)................................................................................................................................47 10. Lancaster Sound (LS)...............................................................................................................................47 11. M'Clintock Channel (MC)........................................................................................................................48 12. Gulf of Boothia (GB) ................................................................................................................................49 13. Foxe Basin (FB) .......................................................................................................................................49 14. Western Hudson Bay (WH)......................................................................................................................50 15. Southern Hudson Bay (SH)......................................................................................................................52 16. Kane Basin (KB) .......................................................................................................................................53 17. Baffin Bay (BB) ........................................................................................................................................54 18. Davis Strait (DS) .......................................................................................................................................55 19. Arctic Basin (AB)......................................................................................................................................57 V. DISCUSSION OF LISTING FACTORS .......................................................................................................58 A. PRESENT OR THREATENED DESTRUCTION, MODIFICATION, OR CURTAILMENT OF THE SPECIES’ HABITAT OR RANGE...............................................................................................................................................60 1. Arctic Climate Change- Overview ............................................................................................................60 2. Biological effects on polar bears ..............................................................................................................72 a. Increased polar bear movements or travel....................................................................................................... 74 b. Polar bear distribution changes and access to prey......................................................................................... 77 2 c. Access to and Alteration of Denning Areas ...................................................................................................... 84 d. Open water swimming ....................................................................................................................................... 87 e. Demographic Effects on Polar Bear.................................................................................................................. 88 3. Biological effects on polar bear prey........................................................................................................94 a. Prey Availability................................................................................................................................................. 94 b. Seal productivity................................................................................................................................................. 99 c. Reduced Access to Prey.................................................................................................................................... 102 4. Projected population specific effects and timing sequence ...................................................................104 B. OVERUTILIZATION FOR COMMERCIAL, RECREATIONAL, SCIENTIFIC, OR EDUCATIONAL PURPOSES...........108 1. Overview of Harvest................................................................................................................................108 History of Polar Bear Hunting and Harvest Management......................................................................................... 108 Principles of Harvest Management ............................................................................................................................. 109 2. Harvest Management by Nation.............................................................................................................111 Canada ......................................................................................................................................................................... 112 Greenland ...................................................................................................................................................................