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Polar Biology

, Volume 38, Issue 12, pp 1983–1992 | Cite as

Characterization of polar bear (Ursus maritimus) diets in the Canadian High Arctic

  • Melissa P. GaliciaEmail author
  • Gregory W. Thiemann
  • Markus G. Dyck
  • Steven H. Ferguson
Original Paper

Abstract

Climate-driven changes in the quality and availability of sea ice habitat (e.g., spatial extent, thickness, and duration of open water) are expected to affect Arctic species primarily through altered foraging opportunities. However, trophic interactions in Arctic marine systems are often poorly understood, especially in remote high-latitude regions. We used quantitative fatty acid signature analysis to examine the diets of 198 polar bears (Ursus maritimus) harvested between 2010 and 2012 in the subpopulations of Baffin Bay, Gulf of Boothia, and Lancaster Sound. The objective was to characterize diet composition and identify ecological factors supporting the high density of polar bears in these regions. Polar bears across the study area fed primarily on ringed seals (Pusa hispida, 41–56 %), although bearded seals (Erignathus barbatus, 11–24 %) and beluga whales (Delphinapterus leucas, 15–19 %) were also important prey. Harp seals (Pagophilus groenlandicus) were a major food source in Baffin Bay. Dietary diversity was greatest in Baffin Bay, perhaps because marine mammals were attracted to the nutrient-rich waters in and downstream from the North Water Polynya. Foraging patterns differed across age and sex classes of polar bear. In Baffin Bay, adult females had high levels of bearded seal in their diet, whereas adult males and subadults consumed high levels of harp seal. Seasonal variation in polar bear foraging was related to known migration patterns of marine mammals. Our results add to existing evidence that polar bears in these three separate subpopulations have a shared conservation status.

Keywords

Canadian Arctic Feeding ecology Marine food web Polar bear (Ursus maritimusQuantitative fatty acid signature analysis (QFASA) 

Notes

Acknowledgments

We are especially grateful to the Hunters and Trappers Associations and Organizations of Nunavut for collecting fat samples from polar bears and marine mammals harvested during their subsistence hunts. A. Coxon and P. Frame (Government of Nunavut–Department of Environment) helped coordinate the collection, organization, and shipment of polar bear samples. Thanks to B. Dunn, B. Young (Fisheries and Oceans Canada), D. Muir, and X. Wang (Environment Canada) for providing additional marine mammal seal samples. S. Budge and C. Barry (Dalhousie University) conducted the gas chromatography. I. Stirling and A. Derocher provided helpful comments on an earlier version of the manuscript. This project was funded by the Natural Sciences and Engineering Research Council (NSERC, Canada), Environment Canada (Grants and Contributions), Kenneth M. Molson Foundation, Nunavut General Monitoring Plan, Northern Scientific Training Program, and York University, Faculty of Graduate Studies.

Supplementary material

300_2015_1757_MOESM1_ESM.docx (105 kb)
Supplementary material 1 (DOCX 105 kb)
300_2015_1757_MOESM2_ESM.docx (19 kb)
Supplementary material 2 (DOCX 19 kb)

References

  1. Amstrup SC (2003) Polar bear, Ursus maritimus. In: Feldhamer GA, Thompson BC, Chapman JA (eds) Wild mammals of North America: biology, management, and conservation, 2nd edn. Johns Hopkins Unversity Press, Baltimore, pp 587–610Google Scholar
  2. Anderson MJ (2001a) Permutation tests for univariate or multivariate analysis of variance and regression. Can J Fish Aquat Sci 58:626–639CrossRefGoogle Scholar
  3. Anderson MJ (2001b) A new method for non-parametric multivariate analysis of variance. Austral Ecol 26:32–46Google Scholar
  4. Atkinson SN, Stirling I, Ramsay MA (1996) Growth in early life and relative body size among adult polar bears (Ursus maritimus). J Zool 239:225–234CrossRefGoogle Scholar
  5. Beck CA, Iverson SJ, Bowen WD, Blanchard W (2007) Sex differences in grey seal diet reflect seasonal variation in foraging behaviour and reproductive expenditure: evidence from quantitative fatty acid signature analysis. J Anim Ecol 76:490–502CrossRefPubMedGoogle Scholar
  6. Best NJ, Bradshaw CJA, Hindell MA, Nichols PD (2003) Vertical stratification of fatty acids in the blubber of southern elephant seals (Mirounga leonina): implications for diet analysis. Comp Biochem Physiol Part B 134:253–263CrossRefGoogle Scholar
  7. Born EW, Teilmann J, Acquarone M, Riget FF (2004) Habitat use of ringed seals (Phoca hispida) in the North Water Area (North Baffin Bay). Arctic 57:129–142CrossRefGoogle Scholar
  8. Bowen WD (1997) Role of marine mammals in aquatic ecosystems. Mar Ecol Prog Ser 158:267–274CrossRefGoogle Scholar
  9. Budge SM, Iverson SJ, Bowen WD, Ackman RG (2002) Among- and within-species variability in fatty acid signatures of marine fish and invertebrates on the Scotian Shelf, Georges Bank, and southern Gulf of St. Lawrence. Can J Fish Aquat Sci 59:886–898CrossRefGoogle Scholar
  10. Budge SM, Iverson SJ, Koopman HN (2006) Studying trophic ecology in marine ecosystems using fatty acids: a primer on analysis and interpretation. Mar Mamm Sci 22:759–801CrossRefGoogle Scholar
  11. Budge SM, Springer AM, Iverson SJ, Sheffield G, Rosa C (2008) Blubber fatty acid composition of bowhead whales, Balaena mysticetus: implications for diet assessment and ecosystem monitoring. J Exp Mar Bio Ecol 359:40–46CrossRefGoogle Scholar
  12. Calvert W, Stirling I (1990) Interactions between polar bears and overwintering walruses in the central Canadian High Arctic. Bears Their Biol Manag 8:351–356CrossRefGoogle Scholar
  13. Chapin FS, Walker BH, Hobbs RJ, Hooper DU, Lawton JH, Sala OE, Tilman D (1997) Biotic control over the functioning of ecosystems. Science 277:500–504CrossRefGoogle Scholar
  14. COSEWIC (2008) COSEWIC Assessment and update status report on the polar bear Ursus maritimus in Canada. Committee on the Status of Endangered Wildlife in Canada, OttawaGoogle Scholar
  15. Derocher AE, Wiig Ø, Andersen M (2002) Diet composition of polar bears in Svalbard and the western Barents Sea. Mar Mamm Sci 25:448–452Google Scholar
  16. Derocher AE, Lunn NJ, Stirling I (2004) Polar bears in a warming climate. Integr Comp Biol 44:163–176CrossRefPubMedGoogle Scholar
  17. Derocher AE, Andersen M, Wiig Ø (2005) Sexual dimorphism of polar bears. J Mamm 86:895–901CrossRefGoogle Scholar
  18. Derocher AE, Andersen M, Wiig Ø, Aars J (2010) Sexual dimorphism and the mating ecology of polar bears (Ursus maritimus) at Svalbard. Behav Ecol Sociobiol 64:939–946CrossRefGoogle Scholar
  19. DFO (2011) Current status of northwest Atlantic harp seals, (Pagophilus groenlandicus). DFO Can Sci Advis Sec Sci Advis Rep 2011/050Google Scholar
  20. Finley KJ, Bradstreet MSW, Miller GW (1990) Summer feeding ecology of harp seals (Phoca groenlandica) in relation to Arctic cod (Boreogadus saida) in the Canadian High Arctic. Polar Biol 10:609–618CrossRefGoogle Scholar
  21. Good P (2000) Permutation tests: a practical guide to resampling methods for testing hypotheses, 2nd edn. Springer, New YorkCrossRefGoogle Scholar
  22. Hamilton SG, Castro de la Guardia L, Derocher AE, Sahanatien V, Tremblay B, Huard D (2014) Projected polar bear sea ice habitat in the Canadian Arctic Archipelago. PLoS One 9:e113746PubMedCentralCrossRefPubMedGoogle Scholar
  23. Heide-Jørgensen MP, Richard P, Dietz R, Laidre KL, Orr J, Schmidt HC (2003) An estimate of the fraction of belugas (Delphinapterus leucas) in the Canadian High Arctic that winter in West Greenland. Polar Biol 26:318–326Google Scholar
  24. Heide-Jørgensen MP, Burt LM, Hansen RG, Nielsen NH, Rasmussen M, Fossette S, Stern H (2013) The significance of the North Water Polynya to arctic top predators. Ambio 42:596–610PubMedCentralCrossRefPubMedGoogle Scholar
  25. Holland MM, Bitz CM, Tremblay B (2006) Future abrupt reductions in the summer Arctic sea ice. Geophys Res Lett 33:1–5CrossRefGoogle Scholar
  26. Iverson SJ, Lang SL, Cooper MH (2001) Comparison of the Bligh and Dyer and Folch methods for total lipid determination in a broad range of marine tissue. Lipids 36:1283–1287CrossRefPubMedGoogle Scholar
  27. Iverson SJ, Field C, Bowen WD, Blanchard W (2004) Quantitative fatty acid signature analysis: a new method of estimating predator diets. Ecol Monogr 74:211–235CrossRefGoogle Scholar
  28. 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: Boyd IL, Wanless S, Camphuysen CJ (eds) Top predators in marine ecosystems. Cambridge, New York, pp 114–133Google Scholar
  29. Iverson SJ, Springer AM, Kitaysky A (2007) Seabirds as indicators of food web structure and ecosystem variability: qualitative and quantitative diet analyses using fatty acids. Mar Ecol Prog Ser 352:235–244CrossRefGoogle Scholar
  30. Kiliaan HPL, Stirling I (1978) Observations on overwintering walruses in the eastern Canadian High Arctic. J Mamm 59:197–200CrossRefGoogle Scholar
  31. Kingsley MCS, Stirling I, Calvert W (1985) The distribution and abundance of seals in the Canadian High Arctic, 1980–82. Can J Fish Aquat Sci 42:1189–1210CrossRefGoogle Scholar
  32. Koopman HN, Iverson SJ, Gaskin DE (1996) Stratification and age-related differences in blubber fatty acids of the male harbour porpoise (Phocoena phocoena). J Comp Physiol B 165:628–639CrossRefPubMedGoogle Scholar
  33. Laidre KL, Stirling I, Lowry LF, Wiig Ø, Heide-Jørgensen MP, Ferguson SH (2008) Quantifying the sensitivity of Arctic marine mammals to climate-induced habitat change. Ecol Appl 18:S97–S125CrossRefPubMedGoogle Scholar
  34. Lowry LF, Burns JJ, Nelson RR (1987) Polar bear, Ursus maritimus, predation on belugas, Delphinapterus leucas, in the Bering and Chukchi seas. Can Field-Nat 101:141–146Google Scholar
  35. Mansfield AW (1967) Distribution of the harbor seal, Phoca vitulina Linnaeus, in Canadian Arctic waters. J Mamm 48:249–257CrossRefGoogle Scholar
  36. Maslanik J, Stroeve J, Fowler C, Emery W (2011) Distribution and trends in Arctic sea ice age through spring 2011. Geophys Res Lett 38:L13502CrossRefGoogle Scholar
  37. McKinney MA, Iverson SJ, Fisk AT, Sonne C, Rigét FF, Letcher RJ, Arts MT, Born EW, Rosing-Asvid A, Dietz R (2013) Global change effects on the long-term feeding ecology and contaminant exposures of East Greenland polar bears. Glob Change Biol 19:2360–2372CrossRefGoogle Scholar
  38. Meynier L, Morel PCH, Chilvers BL, Mackenzie DDS, Duignan PJ (2010) Quantitative fatty acid signature analysis on New Zealand sea lions: model sensitivity and diet estimates. Am Soc Mamm 91:1484–1495Google Scholar
  39. Molnár PK, Derocher AE, Klanjscek T, Lewis MA (2011) Predicting climate change impacts on polar bear litter size. Nat Commun 2:186PubMedCentralCrossRefPubMedGoogle Scholar
  40. Nordstrom C, Wilson L, Iverson SJ, Tollit D (2008) Evaluating quantitative fatty acid signature analysis (QFASA) using harbour seals Phoca vitulina richardsi in captive feeding studies. Mar Ecol Prog Ser 360:245–263CrossRefGoogle Scholar
  41. Obbard ME, Thiemann GW, Peacock E, DeBruyn TD (eds) (2010) Polar bears: proceedings of the 15th working meeting of the IUCN/SSC Polar Bear Specialist Group, 29 June–3 July 2009, Copenhagen, Denmark. Occassional Paper of the IUCN Species Survival Commission, No. 43. International Union for Conservation of Nature, Gland, Switzerland and Cambridge, UKGoogle Scholar
  42. Peacock E, Derocher AE, Thiemann GW, Stirling I (2011) Conservation and management of Canada’s polar bears (Ursus maritimus) in a changing Arctic. Can J Zool 89:371–385CrossRefGoogle Scholar
  43. Peacock E, Sonsthagen SA, Obbard ME, Boltunov A, Regehr EV, Ovsyanikov N, Aars J, Atkinson SN, Sage GK, Hope AG, Zeyl E, Bachmann L, Ehrich D, Scribner KT, Amstrup A, Belikov S, Born EW, Derocher AE, Stirling I, Taylor MK, Wiig Ø, Paetkau D, Talbot SL (2015) Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic. PLoS One 10:e112021PubMedCentralCrossRefPubMedGoogle Scholar
  44. Perovich DK, Richter-Menge JA (2009) Loss of sea ice in the Arctic. Ann Rev Mar Sci 1:417–441CrossRefPubMedGoogle Scholar
  45. Pilfold NW, Derocher AE, Stirling I, Richardson E (2015) Multi-temporal factors influence predation for polar bears in a changing climate. Oikos. doi: 10.1111/oik.02000 Google Scholar
  46. Pomerleau C, Lesage V, Winkler G, Rosenberg B, Ferguson SH (2014) Contemporary diet of bowhead whales (Balaena mysticetus) from the eastern Canadian Arctic inferred from fatty acid biomarkers. Arctic 67:84–92CrossRefGoogle Scholar
  47. R Core Team (2013). R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org
  48. R Development Core Team (2005). R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://R-project.org
  49. 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 Manage 71:2673–2683CrossRefGoogle Scholar
  50. Richard PR, Heide-Jørgensen MP, Orr JR, Dietz R, Smith TG (2001) Summer and autumn movements and habitat use by belugas in the Canadian High Arctic and adjacent areas. Arctic 54:207–222Google Scholar
  51. Rode KD, Peacock E, Taylor M, Stirling I, Born EW, Laidre KL, Wiig Ø (2012) A tale of two polar bear populations: ice habitat, harvest, and body condition. Popul Ecol 54:3–18CrossRefGoogle Scholar
  52. Rode KD, Regehr EV, Douglas DC, Durner G, Derocher AE, Thiemann GW, Budge SM (2014) Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. Glob Change Biol 20:76–88CrossRefGoogle Scholar
  53. Sahanatien V, Derocher AE (2012) Monitoring sea ice habitat fragmentation for polar bear conservation. Anim Conserv 15:397–406CrossRefGoogle Scholar
  54. Screen JA, Simmonds I (2010) The central role of diminishing sea ice in recent Arctic temperature amplification. Nature 464:1334–1337CrossRefPubMedGoogle Scholar
  55. Sergeant DE (1991) Harp seals, man and ice. Can Spec Publ Fish Aquat Sci 114:153Google Scholar
  56. Smith TG (1980) Polar bear predation of ringed and bearded seals in the land-fast sea ice habitat. Can J Zool 58:2201–2209CrossRefGoogle Scholar
  57. Smith TG, Martin AR (1994) Distribution and movements of belugas, Delphinapterus leucas, in the Canadian High Arctic. Can J Fish Aquat Sci 51:1653–1663CrossRefGoogle Scholar
  58. Smith TG, Sjare B (1990) Predation of belugas and narwhals by polar bears in nearshore areas of the Canadian High Arctic. Arctic 43:99–102CrossRefGoogle Scholar
  59. Stewart DB, Akeeagok A, Amarualik R, Panipakutsuk S, Taqtu A (1995) Local knowledge of beluga and narwhal from four communities in Arctic Canada. Can Tech Rep Fish Aquat Sci 2065Google Scholar
  60. Stirling I (1980) The biological importance of polynyas in the Canadian Arctic. Arctic 33:303–315CrossRefGoogle Scholar
  61. Stirling I (1997) The importance of polynyas, ice edges, and leads to marine mammals and birds. J Mar Syst 10:9–21CrossRefGoogle Scholar
  62. Stirling I, Archibald WR (1977) Aspects of predation of seals by polar bears. J Fish Res Board Can 34:1126–1129CrossRefGoogle Scholar
  63. Stirling I, Derocher AE (1993) Possible impacts of climatic warming on polar bears. Arctic 46:240–245CrossRefGoogle Scholar
  64. Stirling I, Derocher AE (2012) Effects of climate warming on polar bears: a review of the evidence. Glob Change Biol 18:2694–2706CrossRefGoogle Scholar
  65. Stirling I, McEwan EH (1975) The caloric value of whole ringed seals (Phoca hispida) in relation to polar bear (Ursus maritimus) ecology and hunting behavior. Can J Zool 53:1021–1027CrossRefPubMedGoogle Scholar
  66. Stirling I, Øritsland NA (1995) Relationships between estimated of ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic. Arctic 2612:2594–2612Google Scholar
  67. Stroeve J, Holland MM, Meier W, Scambos T, Serreze M (2007) Arctic sea ice decline: faster than forecast. Geophys Res Lett 34:1–5CrossRefGoogle Scholar
  68. Stroeve JC, Maslanik J, Serreze MC, Rigor I, Meier W, Fowler C (2011) Sea ice response to an extreme negative phase of the Arctic Oscillation during winter 2009/2010. Geophys Res Lett 38:L02502CrossRefGoogle Scholar
  69. Thiemann GW, Budge SM, Iverson SJ, Stirling I (2007) Unusual fatty acid biomarkers reveal age- and sex-specific foraging in polar bears (Ursus maritimus). Can J Zool 85:505–517CrossRefGoogle Scholar
  70. Thiemann GW, Iverson SJ, Stirling I (2008a) Polar bear diets and Arctic marine food webs: insights from fatty acid analysis. Ecol Monogr 78:591–613CrossRefGoogle Scholar
  71. Thiemann GW, Iverson SJ, Stirling I (2008b) Variation in blubber fatty acid composition among marine mammals in the Canadian Arctic. Mar Mamm Sci 24:91–111CrossRefGoogle Scholar
  72. Thiemann GW, Derocher AE, Stirling I (2008c) Polar bear Ursus maritimus conservation in Canada: an ecological basis for identifying designatable units. Oryx 42:504–515CrossRefGoogle Scholar
  73. Thiemann GW, Iverson SJ, Stirling I, Obbard ME (2011) Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore. Oikos 120:1469–1478CrossRefGoogle Scholar
  74. Welch HE, Bergmann MA, Siferd TD, Martin KA, Curtis MF, Crawford RE, Conover RJ, Hop H (1992) Flow through the marine of the energy ecosystem Lancaster Sound region, Arctic Canada. Arctic 45:343–357CrossRefGoogle Scholar
  75. Young BG, Loseto LL, Ferguson SH (2010) Diet differences among age classes of Arctic seals: evidence from stable isotope and mercury biomarkers. Polar Biol 33:153–162CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Melissa P. Galicia
    • 1
    Email author
  • Gregory W. Thiemann
    • 2
  • Markus G. Dyck
    • 3
  • Steven H. Ferguson
    • 4
  1. 1.Department of BiologyYork UniversityTorontoCanada
  2. 2.Faculty of Environmental StudiesYork UniversityTorontoCanada
  3. 3.Wildlife Research Section, Department of EnvironmentGovernment of NunavutIgloolikCanada
  4. 4.Fisheries and Oceans CanadaWinnipegCanada

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