Dear all - for those of you working with furry marine mammals and nutritional stress/effects of a changing climate, we have a new paper out on polar bears that might be of interest to you:
Bechshøft TØ, Sonne C, Rigét FF, Letcher RJ, Novak MA, Henchey E, Meyer JS, Eulaers I, Jaspers V, Covaci A & Dietz R. 2013. Polar bear stress hormone cortisol fluctuates with the North Atlantic Oscillation climate index. Polar Biology, 36: 1525-1529 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. For a pdf copy, please either contact me or follow the link: http://link.springer.com/article/10.1007%2Fs00300-013-1364-y Wishing you all a grand weekend :) Best, Thea Thea Bechshøft, Biologist, MSc, PhD Department of Bioscience Aarhus University Frederiksborgvej 399, PO Box 358 4000 Roskilde, Denmark E-mail: [email protected]<mailto:[email protected]>
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