A tale of two polar bear populations: ice habitat, harvest, and body condition
Correction(s) for this article
-
Erratum to: Population Ecology, Vol. 54, No. 1
- Volume 54Issue 2Population Ecology
- pages: 367-367
- First Published online: February 1, 2012
Corresponding Author
Karyn D. Rode
US Fish and Wildlife Service, Marine Mammals Management, 1011 E Tudor Road, 99503 Anchorage, AK, USA
[email protected]Search for more papers by this authorElizabeth Peacock
Department of Environment, Government of Nunavut, X0A 0L0 Igloolik, NU, Canada
US Geological Survey, Alaska Science Center, 4210 University Drive, 99508 Anchorage, AK, USA
Search for more papers by this authorMitchell Taylor
Faculty of Science and Environmental Studies, Lakehead University, 955 Oliver Road, P7B 5E1 Thunder Bay, ON, Canada
Search for more papers by this authorIan Stirling
Wildlife Research Division, Environment Canada, 5320 122 St., T6G 3S5 Edmonton, AB, Canada
Department of Biological Sciences, University of Alberta, T6G 2E9 Edmonton, AB, Canada
Search for more papers by this authorErik W. Born
Greenland Institute of Natural Resources, P.O. Box 570, 3900 Nuuk, Greenland
Search for more papers by this authorKristin L. Laidre
Polar Science Center, Applied Physics Lab, University of Washington, 1013 NE, 40th Street, 98105 Seattle, WA, USA
Greenland Institute of Natural Resources, P.O. Box 570, 3900 Nuuk, Greenland
Search for more papers by this authorØystein Wiig
National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172, 0318 Oslo, Blindern, Norway
Search for more papers by this authorCorresponding Author
Karyn D. Rode
US Fish and Wildlife Service, Marine Mammals Management, 1011 E Tudor Road, 99503 Anchorage, AK, USA
[email protected]Search for more papers by this authorElizabeth Peacock
Department of Environment, Government of Nunavut, X0A 0L0 Igloolik, NU, Canada
US Geological Survey, Alaska Science Center, 4210 University Drive, 99508 Anchorage, AK, USA
Search for more papers by this authorMitchell Taylor
Faculty of Science and Environmental Studies, Lakehead University, 955 Oliver Road, P7B 5E1 Thunder Bay, ON, Canada
Search for more papers by this authorIan Stirling
Wildlife Research Division, Environment Canada, 5320 122 St., T6G 3S5 Edmonton, AB, Canada
Department of Biological Sciences, University of Alberta, T6G 2E9 Edmonton, AB, Canada
Search for more papers by this authorErik W. Born
Greenland Institute of Natural Resources, P.O. Box 570, 3900 Nuuk, Greenland
Search for more papers by this authorKristin L. Laidre
Polar Science Center, Applied Physics Lab, University of Washington, 1013 NE, 40th Street, 98105 Seattle, WA, USA
Greenland Institute of Natural Resources, P.O. Box 570, 3900 Nuuk, Greenland
Search for more papers by this authorØystein Wiig
National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172, 0318 Oslo, Blindern, Norway
Search for more papers by this authorAn erratum to this article can be found at http://doi.org/10.1007/s10144-012-0304-y.
Abstract
One of the primary mechanisms by which sea ice loss is expected to affect polar bears is via reduced body condition and growth resulting from reduced access to prey. To date, negative effects of sea ice loss have been documented for two of 19 recognized populations. Effects of sea ice loss on other polar bear populations that differ in harvest rate, population density, and/or feeding ecology have been assumed, but empirical support, especially quantitative data on population size, demography, and/or body condition spanning two or more decades, have been lacking. We examined trends in body condition metrics of captured bears and relationships with summertime ice concentration between 1977 and 2010 for the Baffin Bay (BB) and Davis Strait (DS) polar bear populations. Polar bears in these regions occupy areas with annual sea ice that has decreased markedly starting in the 1990s. Despite differences in harvest rate, population density, sea ice concentration, and prey base, polar bears in both populations exhibited positive relationships between body condition and summertime sea ice cover during the recent period of sea ice decline. Furthermore, females and cubs exhibited relationships with sea ice that were not apparent during the earlier period (1977–1990s) when sea ice loss did not occur. We suggest that declining body condition in BB may be a result of recent declines in sea ice habitat. In DS, high population density and/or sea ice loss, may be responsible for the declines in body condition.
References
- Aars J, Lunn NJ, Derocher AE (2006) Polar bears. In: Proceedings of the 14th working meeting of the world conservation union species survival commission (IUCN/SSC) Polar Bear Specialist Group. Seattle
- Amstrup SC, Marcot BG, Douglas DC (2008) A Bayesian network modeling approach to forecasting the 21st century worldwide status of polar bears. In: ET De Weaver, CM Bitz, LB Tremblay (eds) Arctic sea ice decline: observations, projections, mechanisms, and implications. Geophys Monogr 180, American Geophysical Union. Washington, DC, pp 213–268
- Barbraud C, Weimerskirch H (2003) Climate and density shape population dynamics of a marine top predator. Proc R Soc B 270: 2111–2116
- Born EW (1995) Status of the polar bear in Greenland. In: Ø Wiig, EW Born, G Garner (eds) Polar bears. Proceedings of the 11th working meeting of the IUCN/SSC Polar Bear Specialist Group. Occasional paper of IUCN/SSC No 10. Gland, pp 81–103
- Born EW, Heilmann A, Holm LK, Laidre KL (2011) Polar bears in Northwest Greenland—an interview survey about the catch and the climate. In: Monogr on Greenland 351, Man and Society 41, Museum Tusculanum Press, University of Copenhagen, Copenhagen, Denmark, pp 1–233
- Boyce MS, Blanchard BM, Knight RR, Servheen C (2001) Population viability for grizzly bears: a critical review. Int Assoc Bear Res Manage Monogr Ser No. 4, International Bear Association, Kalispell
- Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach, 2nd edn. Springer, New York
- de Little SC, Bradshaw CJA, McMahon CR, Hindell MA (2007) Complex interplay between intrinsic and extrinsic drivers of long-term survival trends in southern elephant seals. Biomed Ecol 7: 3
- Department of Fisheries and Oceans (DFO) (2010) Current status of northwest Atlantic harp seals, Pagophilus groenlandicus. Science Advisory Report 2009/074. DFO Canadian Scientific Advisory Secretariat Science Advisory Report 2009/074, Canadian Science Advisory Secretariat, Ottawa
- Derocher AE, Stirling I (1994) Age-specific reproduction of female polar bears (Ursus maritimus). J Zool 234: 527–536
- Derocher AE, Stirling I (1996) Aspects of survival in juvenile polar bears. Can J Zool 74: 1246–1252
- Derocher AE, Stirling I (1998a) Geographic variation in growth of polar bears (Ursus maritimus). J Zool 245: 65–72
- Derocher AE, Stirling I (1998b) Maternal investment and factors affecting offspring size in polar bears (Ursus maritimus). J Zool 245: 253–260
- Derocher AE, Wiig Ø (2002) Postnatal growth in body length and mass of polar bears (Ursus maritimus) at Svalbard. J Zool 256: 343–349
- Derocher AE, Andriashek DS, Stirling I (1993) Terrestrial foraging by polar bears during the ice-free period in western Hudson Bay. Arctic 46: 251–254
- Derocher AE, Lunn NJ, Stirling I (2004) Polar bears in a warming climate. Integr Comp Biol 44: 163–176
- Derocher AE, Andersen M, Wiig Ø (2005) Sexual dimorphism of polar bears. J Mammal 86: 895–901
- Dowsley M, Wenzel GW (2008) “The time of the most polar bears”: a co-management conflict in Nunavut. Arctic 61: 177–189
- Durner GM, Douglas DC, Nielson RM, Amstrup SC, McDonald TL, Stirling I, Maurtizen M, Born EW, Wiig Ø, DeWeaver E, Serreze MC, Belikov SE, Holland MM, Maslanik J, Aars J, Bailey DA, Derocher AE (2009) Predicting 21st-century polar bear habitat distribution from global climate models. Ecol Monogr 79: 25–58
- Furnell DJ, Oolooyuk D (1980) Polar bear predation on ringed seals in ice-free water. Can Field Nat 94: 88–89
- Gotelli NJ, Ellison AM (2004) A primer of ecological statistics. Sinauer Associates, Sunderland
- Green RH (1979) Sampling design and statistical methods for environmental biologists. Wiley, New York
- Harrell FE (2009) Regression modeling strategies. Springer, New York
- Iverson SJ, Stirling I, Lang SLC (2006) Spatial and temporal variation in the diets of polar bears across the Canadian Arctic: indicators of changes in prey populations and environment. In: IL Boyd, S Wanless, CJ Camphuysen (eds) Top predators in marine ecosystems. Cambridge University Press, New York, pp 98–117
10.1017/CBO9780511541964.008 Google Scholar
- Kingsley MCS, Stirling I, Calvert W (1985) The distribution and abundance of seals in the Canadian High Arctic, 1980–1982. Can J Fish Aqu Sci 42: 1189–1210
- Kotierk M (2010) Elder and hunter knowledge of Davis Strait polar bears, climate change, and Inuit participation. Government of Nunavut, Department of Environment Report, Igloolik
- Laidre KL, Estes JA, Tinker MT, Bodkin J, Monson D, Schneider K (2006) Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline. J Anim Ecol 75: 978–989
- Leberg PL, Brisbin IL, Smith MH, White GC (1989) Factors affecting the analysis of growth patterns in large mammals. J Mammal 70: 275–283
- Miller SD, Sellers RA, Keay JA (2003) Effects of hunting on brown bear cub survival and litter size in Alaska. Ursus 14: 130–152
- Noyce KV, Garshelis DL (1994) Body size and blood characteristics as indicators of condition and reproductive performance in black bears. Int Conf Bear Res Manag 9: 481–496
- Obbard ME (2008) Southern Hudson Bay polar bear project, Final Report. Ontario Ministry of Natural Resources, Peterborough
- Obbard ME, Howe EJ (2008) Demography of black bears in hunted and unhunted areas of the boreal forest of Ontario. J Wildl Manag 72: 869–880
- Obbard ME, Cattet MRL, Moody T, Walton LR, Potter D, Inglis J, Chenier C (2006) Temporal trends in the body condition of Southern Hudson Bay polar bears. Climate Change Res Info Note #3, Ontario Ministry of Natural Resources, Ontario
- Obbard M, Thiemann G, Peacock E, DeBruyn T (2010) Proceedings of the 15th working meeting of the IUCN/SSC Polar Bear Specialist Group, Copenhagen, Denmark. 29 June–3 July 2009. IUCN, Gland
- Paetkau D, Amstrup SC, Born EW, Calvert W, Derocher AE, Garner GW, Messier F, Stirling I, Taylor MK, Wiig Ø, Strobeck C (1999) Genetic structure of the world's polar bear populations. Mol Ecol 8: 1571–1584
- Peacock E (2009) Davis Strait Polar Bear Population Inventory. Final Report, Government of Nunavut, Department of Environment Report. Government of Nunavut, Igloolik
- Perovich DK, Richter-Menge A (2009) Loss of sea ice in the Arctic. Annu Rev Mar Sci 1: 417–441
- Regehr EV, Lunn NJ, Amstrup SC, Stirling I (2007) Effects of earlier sea ice breakup on survival and population size of polar bears in Western Hudson Bay. J Wildl Manag 71: 2673–2683
- Regehr EV, Hunter CM, Caswell H, Amstrup SC, Stirling I (2010) Survival and breeding of polar bears in the southern Beaufort Sea in relation to sea ice. J Anim Ecol 79: 117–127
- Rode KD, Amstrup SC, Regehr EV (2010) Reduced body size and cub recruitment in polar bears associated with sea ice decline. Ecol Appl 20: 768–782
- Russell RH (1975) The food habits of polar bears of James Bay and Southwest Hudson Bay in summer and autumn. Arctic 28: 117–129
- Schwartz CC, Haroldson MA, White GC, Harris RB, Keating KA, Moody D, Servheen C (2006) Temporal, spatial, and environmental influences on the demographics of grizzly bears in the Greater Yellowstone ecosystem. Wildl Monogr 161: 1–68
10.2193/0084-0173(2006)161[1:TSAEIO]2.0.CO;2 Google Scholar
- Stirling I, Kiliian HPL (1980) Population ecology studies of the polar bear in northern Labrador. Canadian Wildlife Service Occasional Paper 42. Canadian Wildlife Service, Edmonton
- Stirling I, Parkinson CL (2006) Possible effects of climate warming on selected populations of polar bears (Ursus maritimus) in the Canadian Arctic. Arctic 59: 261–275
- Stirling I, Calvert W, Andriashek D (1980) Population ecology studies of the polar bear in the area of southeastern Baffin Island. Canadian Wildlife Service Occasional Paper 44. Canadian Wildlife Service, Edmonton
- Stirling I, Kingsley M, Calvert W (1982) The distribution and abundance of seals in the eastern Beaufort Sea, 1974–79. Canadian Wildlife Service Occasional Paper 47. Canadian Wildlife Service, Edmonton
- Stirling I, Lunn NJ, Iacozza J (1999) Long-term trends in the population ecology of polar bears in Western Hudson Bay in relation to climatic change. Arctic 52: 294–306
- Stirling I, McDonald TL, Richardson ES, Regehr EV, Amstrup SC (2011) Polar bear population status in the Northern Beaufort Sea, Canada, 1971–2006. Ecol Appl 21: 859–876
- Taylor MK (1994) Density-dependent population regulation of black, brown and polar bears. In: 9th international conference on bear research and management. International Bear Association, Missoula
- Taylor M, Lee J (1995) Distribution and abundance of Canadian polar bear populations—a management perspective. Arctic 48: 147–154
- Taylor MK, Akeeagok S, Andriashek D, Barbour W, Born EW, Calvert W, Cluff HD, Laake J, Rosing-Asvid A, Stirling I, Messier F (2001) Delineating Canadian and Greenland polar bear (Ursus maritimus) populations by cluster analysis of movements. Can J Zool 79: 690–709
- Taylor MK, Laake J, McLoughlin PD, Born EW, Cluff HD, Ferguson SH, Rosing-Asvid A, Schweinsburg R, Messier F (2005) Demography and viability of a hunted population of polar bears. Arctic 58: 203–214
- Thiemann GW, Iverson SJ, Stirling I (2008) Polar bear diets and arctic marine food webs: insights from fatty acid analysis. Ecol Monogr 78: 591–613
- United Nations Environmental Program (UNEP) (2007) Global outlook for ice and snow. United Nations Environment Programme, United Nations, Nairobi
- Zedrosser A, Dahle B, Swenson JE (2006) Population density and food conditions determine adult female body size in brown bears. J Mammal 87: 510–518