Hunting triggers rise in wolves' stress levels

Posted Nov 29, 2014 by Tim Sandle
In territories where wolves are regularly hunted, scientists have noted a rise in hormones responsible for stress in the animals.
Wolf attacks on sheep in France rose to 4 800 by August in 2014.
Wolf attacks on sheep in France rose to 4,800 by August in 2014.
Juan José González Vega
In Northern Canada, where wolves are hunted as part of government control programs, the intensification of culling has consequences for the animals’ hormone levels. This has consequences for the health of the pack. Here there are potential implications for wildlife health, welfare, long-term survival and behavior.
Scientists, based at the Universities of Calgary and Victoria in Canada, argue that high levels of stress hormones and altered levels of reproductive hormones may reflect disruptions in the wolves’ social structure and could affect their vulnerability to disease.
The evidence came, according to a research brief, from hair collected from wolves killed by hunters over a period of 13 years. Hair samples were important because steroid hormones are incorporated into growing hair from the follicles, levels of cortisol, progesterone, and testosterone measured in hair reflect long-term hormone levels in the animals.
From this analysis it was found that from among 130 wolves from heavily hunted tundra-taiga populations in Canada, the scientists found significantly higher levels of the stress hormone cortisol than in a group of 30 wolves from boreal forests with less intensive hunting.
The findings have been published in the journal Functional Ecology. The research report is headed "Heavily hunted wolves have higher stress and reproductive steroids than wolves with lower hunting pressure."