Advertisement

Polar Biology

, Volume 36, Issue 10, pp 1525–1529 | Cite as

Polar bear stress hormone cortisol fluctuates with the North Atlantic Oscillation climate index

  • Thea Ø. Bechshøft
  • Christian Sonne
  • Frank F. Rigét
  • Robert J. Letcher
  • Melinda A. Novak
  • Elizabeth Henchey
  • Jerrold S. Meyer
  • Igor Eulaers
  • Veerle L. B. Jaspers
  • Adrian Covaci
  • Rune Dietz
Short Note

Abstract

Polar bears are heavily dependent on sea ice for hunting sufficient prey to meet their energetic needs. When the bears are left fasting, it may cause a rise in the levels of the stress hormone cortisol. Cortisol is the major corticosteroid hormone in most mammals, including polar bears. Production and regulation of this stress hormone are vital for the body as it is part of a myriad of processes, including in relation to metabolism, growth, development, reproduction, and immune function. In the present study, we examined the correlation between East Greenland polar bear hair cortisol concentration (HCC), a matrix that reflects longer-term hormone levels, and the fluctuations of the North Atlantic Oscillation (NAO) index, a large-scale climate phenomenon applied as a proxy for sea ice extent in the Greenland Sea along the coast of East Greenland. In doing so, a significant positive correlation (r = 0.88; p = 0.0004) was found between polar bear hair cortisol and the NAO, explaining 77 % of the variation in HCC observed between years over the period 1989–2009. This result indicates that interannual fluctuations in climate and ice cover have a substantial influence on longer-term cortisol levels in East Greenland polar bears. Further research into the implications and consequences inherent in this correlation are recommended, preferably across multiple polar bear populations.

Keywords

Polar bear Hair Cortisol Climate NAO Glucocorticoids Stress 

Notes

Acknowledgments

Erik W. Born and Aqqalu Rosing-Asvid are acknowledged for collecting the East Greenland polar bear hair samples during the period 1988–1991. Jonas Brønlund and local hunters are acknowledged for organizing the later sampling in East Greenland. Financial support was provided by the Prince Albert II of Monaco Foundation, the Danish Cooperation for Environment in the Arctic, the Commission for Scientific Research in Greenland, the Funds for Scientific Research Flanders, and the University of Antwerp. The hair cortisol assays were supported by US National Institutes of Health Grants RR11122 to MAN and RR00168 to the New England Primate Center.

References

  1. Bader J, Mesquita MDS, Hodges KI, Keenlyside N, Østerhus S, Miles M (2011) A review on Northern Hemisphere sea-ice, storminess and the North Atlantic Oscillation: observations and projected changes. Atmos Res 101:809–834CrossRefGoogle Scholar
  2. Bechshøft TØ, Sonne C, Dietz R, Born EW, Novak MA, Henchey E, Meyer JS (2011) Cortisol levels in hair of East Greenland polar bears. Sci Total Environ 409:831–834CrossRefPubMedGoogle Scholar
  3. Bechshøft TØ, Rigét FF, Sonne C, Letcher RJ, Muir DCG, Novak MA, Henchey E, Meyer JS, Eulaers I, Jaspers V, Eens M, Covaci A, Dietz R (2012a) Measuring environmental stress in East Greenland polar bears, 1892–1927 and 1988–2009: what does hair cortisol tell us? Environ Int 45:15–21CrossRefPubMedGoogle Scholar
  4. Bechshøft TØ, Sonne C, Dietz R, Born EW, Muir DCG, Letcher RJ, Novak MA, Henchey E, Meyer JS, Jenssen BM, Villanger GD (2012b) Associations between complex OHC mixtures and thyroid and cortisol hormone levels in East Greenland polar bears. Environ Res 116:26–35CrossRefPubMedGoogle Scholar
  5. Bennett A, Hayssen V (2010) Measuring cortisol in hair and saliva from dogs: coat color and pigment differences. Domest Anim Endocrinol 39:171–180CrossRefPubMedGoogle Scholar
  6. Bennett KA, Moss SEW, Pomeroy P, Speakman JR, Fedak MA (2012) Effects of handling regime and sex on changes in cortisol, thyroid hormones and body mass in fasting grey seal pups. Comp Biochem Physiol Part A161:69–76CrossRefGoogle Scholar
  7. Bortolotti GR, Marchant TA, Blas J, German T (2008) Corticosterone in feathers is a long-term, integrated measure of avian stress physiology. Funct Ecol 22:494–500CrossRefGoogle Scholar
  8. Calvert W, Ramsay MA (1998) Evaluation of age determination of polar bears by counts of cementum growth layer groups. Ursus 10:449–453Google Scholar
  9. Cherry SG, Derocher AE, Stirling I, Richardson ES (2009) Fasting physiology of polar bears in relation to environmental change and breeding behavior in the Beaufort Sea. Polar Biol 32:383–391CrossRefGoogle Scholar
  10. Chow BA, Hamilton J, Cattet MRL, Stenhouse G, Obbard ME, Vijayan MM (2011) Serum corticosteroid binding globulin expression is modulated by fasting in polar bears (Ursus maritimus). Comp Biochem Physiol Part A 158:111–115CrossRefGoogle Scholar
  11. Constable S, Parslow A, Dutton G, Rogers T, Hogg C (2006) Urinary cortisol sampling: a non-invasive technique for examining cortisol concentrations in the Weddell seal, Leptonychotes weddellii. Zoo Biol 25:137–144CrossRefGoogle Scholar
  12. Derocher AE (2005) Population ecology of polar bears at Barents Sea, Norway. Popul Ecol 47:27–267CrossRefGoogle Scholar
  13. Faucitano L, Saucier L, Correa JA, Méthot S, Giguère A, Foury A, Mormède P, Bergeron R (2006) Effect of feed texture, meal frequency and pre-slaughter fasting on carcass and meat quality, and urinary cortisol in pigs. Meat Sci 74:697–703CrossRefPubMedGoogle Scholar
  14. Ferguson SH, Stirling I, McLoughlin P (2005) Climate change and ringed seal (Phoca hispida) recruitment in western Hudson Bay. Mar Mammal Sci 21:121–135CrossRefGoogle Scholar
  15. Hamilton JW (2007) Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos). Thesis, University of Waterloo, M.ScGoogle Scholar
  16. Handa RJ, Burgess LH, Kerr JE, O’Keefe JA (1994) Gonadal-steroid hormone receptors and sex differences in the hypothalamo–pituitary–adrenal axis. Horm Behav 28:464–476CrossRefPubMedGoogle Scholar
  17. Hiller-Sturmhöfel S, Bartke A (1998) The endocrine system: an overview. Alcohol Health Res World 22:153–164PubMedGoogle Scholar
  18. Hinkler J, Hansen BU, Tamstorf MP, Sigsgaard C, Petersen D (2008) Snow and snow-cover in central Northeast Greenland. Adv Ecol Res 40:175–195CrossRefGoogle Scholar
  19. Hurrell JW (1995) Decadal trends in the North Atlantic Oscillation: regional temperatures and precipitation. Science 269:676–679CrossRefPubMedGoogle Scholar
  20. Hurrell JW (2012) National Centre for Atmospheric Research, Winter (December–March) Station Based NAO Index. https://climatedataguide.ucar.edu/sites/default/files/cas_data_files/asphilli/nao_station_djfm.txt. Accessed 3 June 2013
  21. Hurrell JW, Kushnir Y, Ottersen G, Visbeck M (2003) The North Atlantic Oscillation: climatic significance and environmental impact. AGU, WashingtonCrossRefGoogle Scholar
  22. Koren L, Mokady O, Karaskov T, Klein J, Koren G, Geffen E (2002) A novel method using hair for determining hormonal levels in wildlife. Anim Behav 63:403–406CrossRefGoogle Scholar
  23. Lupica SJ, Turner JW (2009) Validation of enzyme-linked immunosorbent assay for measurement of faecal cortisol in fish. Aquacult Res 40:437–441CrossRefGoogle Scholar
  24. Macbeth BJ, Cattet MRL, Stenhouse GB, Gibeau ML, Janz DM (2010) Hair cortisol concentration as a noninvasive measure of long-term stress in free ranging grizzly bears (Ursus arctos): considerations with implications for other wildlife. Can J Zool 88:935–949CrossRefGoogle Scholar
  25. Macbeth BJ, Cattet MRL, Obbard ME, Middel K, Janz DM (2012) Evaluation of hair cortisol concentration as a biomarker of long-term stress in free-ranging polar bears. Wildlife Soc B 36:747–758CrossRefGoogle Scholar
  26. Obbard ME, Thiemann GW, Peacock E, DeBruyn TD (2010) Polar bears: proceedings of the 15th working meeting of the IUCN/SSC polar bear specialist group, Copenhagen, Denmark, 29 June–3 July 2009. IUCN, Gland, p 235Google Scholar
  27. Okuliarová M, Sárniková B, Rettenbacher S, Skrobánek P, Zeman M (2010) Yolk testosterone and corticosterone in hierarchical follicles and laid eggs of Japanese quail exposed to long-term restraint stress. Gen Comp Endocrinol 165:91–96CrossRefPubMedGoogle Scholar
  28. Oskam IC, Ropstad E, Lie E, Derocher AE, Wiig O, Dahl E, Larsen S, Skaare JU (2004) Organochlorines affect the steroid hormone cortisol in free-ranging polar bears (Ursus maritimus) at Svalbard, Norway. J Toxicol Environ Health Part A 67:959–977CrossRefPubMedGoogle Scholar
  29. Pedersen A (1945) Der Eisbär (Thalarctos Maritimus Phipps). Aktieselskabet E. Bruun & Co.s trykkerier, KøbenhavnGoogle Scholar
  30. 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 79:117–127CrossRefPubMedGoogle Scholar
  31. Rosing-Asvid A, Born EW, Kingsley MCS (2002) Age at sexual maturity of males and timing of the mating season of polar bears (Ursus maritimus) in Greenland. Polar Biol 25:878–883Google Scholar
  32. Sonne C (2010) Health effects from long-range transported contaminants in Arctic top predators: an integrated review based on studies of polar bears and relevant model species. Environ Int 36:461–491CrossRefPubMedGoogle Scholar
  33. Stirling I, Derocher AE (2012) Effects of climate warming on polar bears: a review of the evidence. Glob Change Biol 18:2694–2706CrossRefGoogle Scholar
  34. 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 52:294–306Google Scholar
  35. Tryland M, Brun E, Derocher AE, Arnemo JM, Kierulf P, Ølberg RA, Wiig Ø (2002) Plasma biochemical values from apparently healthy free-ranging polar bears from Svalbard. J Wildl Dis 38:566–575PubMedGoogle Scholar
  36. Van der Staay FJ, De Groot J, Van Reenen CG, Hoving-Bolink AH, Schuurman T, Schmidt BH (2007) Effects of Butafosfan on salivary cortisol and behavioral response to social stress in piglets. J Vet Pharmacol Ther 30:410–416CrossRefGoogle Scholar
  37. Vinje T (2001) Anomalies and trends of sea-ice extent and atmospheric circulation in the Nordic Seas in the period 1864–1998. J Clim 14:255–267CrossRefGoogle Scholar
  38. Vongraven D, Aars J, Amstrup S, Atkinson SN, Belikov S, Born EW, DeBruyn TD, Derocher AE, Durner G, Gill M, Lunn N, Obbard ME, Omelak J, Peacock E, Ovsyanikov N, Richardson E, Sahanatien V, Stirling I, Wiig Ø (2012) A circumpolar monitoring framework for polar bears. Ursus 5:1–66CrossRefGoogle Scholar
  39. Ward JR, Henricks DM, Jenkins TC, Bridges WC (1992) Serum hormone and metabolite concentrations in fasted young bulls and steers. Dom Anim Endocrinol 9:97–103CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Thea Ø. Bechshøft
    • 1
  • Christian Sonne
    • 1
  • Frank F. Rigét
    • 1
  • Robert J. Letcher
    • 2
  • Melinda A. Novak
    • 3
  • Elizabeth Henchey
    • 3
  • Jerrold S. Meyer
    • 3
  • Igor Eulaers
    • 4
  • Veerle L. B. Jaspers
    • 4
  • Adrian Covaci
    • 5
  • Rune Dietz
    • 1
  1. 1.Department of BioscienceAarhus UniversityRoskildeDenmark
  2. 2.Wildlife and Landscape Science Directorate, Environment Canada, National Wildlife Research CentreCarleton UniversityOttawaCanada
  3. 3.Department of PsychologyUniversity of MassachusettsAmherstUSA
  4. 4.Department of BiologyUniversity of AntwerpWilrijkBelgium
  5. 5.Toxicological CenterUniversity of AntwerpWilrijkBelgium

Personalised recommendations