November 27, 2013
Grizzlies' stress hormones related to low salmon consumption
Grizzly bears that consume low amounts of salmon have higher levels of cortisol, a stress hormone that helps the species cope with change but may have negative health effects in the long-term, say the authors of a new study released today in the scientific journal PLOS ONE.
Researchers from the University of Victoria, the University of Calgary, and the Raincoast Conservation Foundation examined stress hormones in hair samples of salmon-eating grizzly bears from coastal BC. The researchers found higher levels of the stress hormone, cortisol, in coastal bears that consumed less salmon.
“This pattern would occur if bears are nutritionally stressed by lack of salmon or if bears experience social stress caused by intense competition when salmon numbers are low,” explains Dr. Heather Bryan, Hakai postdoctoral researcher at UVic and the study’s lead author.
“Our findings highlight how salmon management can influence the health of coastal wildlife,” says Dr. Chris Darimont, UVic geography professor, Raincoast science director and a co-author of the study.
The report, Stress and reproductive hormones in grizzly bears reflect nutritional benefits and social consequences of a salmon foraging niche, is co-authored by Judit Smits and Katherine Wynne-Edwards, professors in Veterinary Medicine at the University of Calgary, and Paul Paquet, professor in geography at the University of Victoria and director of science for the Raincoast Conservation Foundation. Bryan was a PhD student at the University of Calgary when completing her work for the study.
The researchers also collaborated with the Heiltsuk Integrated Resource Management Department on behalf of the Heiltsuk Nation and the Qqs Projects Society, a Heiltsuk-run non-governmental organization.
The report is available online at PLOS ONE http://dx.plos.org/10.1371/journal.pone.0080537
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Dr. Heather Bryan (Geography/Postdoctoral Fellow) at 604-848-5570 (cell) or email@example.com
Dr. Chris Darimont (Geography) at 250-853-3287(office), 250-589-7873(cell), firstname.lastname@example.org; or Twitter: @ChrisDarimont
Anne MacLaurin (Social Sciences Communications) at 250-217-4259 (cell) or email@example.com