(University of Washington press release via Futurity.org, 27 June 2011) -- The caribou population has been declining in the region for several decades causing speculation that the entire population could be gone in 70 years. Further, in the area of the petroleum-rich Athabasca Oil Sands in the northern part of the Canadian province, some researchers predict they could disappear in as little as 30 years. While the drop in caribou in recent decades is certain, populations have held relatively steady in the last four years, says Samuel Wasser, conservation biologist at the University of Washington. In a new study, published in the journal Frontiers in Ecology and the Environment, Wasser calls for controlling the impact of human activities before resorting to more drastic actions such as removing wolves from the area. ...
Scat samples from caribou, moose, and wolves, well preserved because of sub-freezing temperatures, were collected in the winters of 2006, 2007, and 2009. In 2009, four teams of highly trained scat-detection dogs led to the recovery of 2,000 samples of caribou, moose, and wolf scat in 10 weeks. In examining the samples, researchers determined habitat preferences for each species, their abundance, the type and quality of food consumed, and hormone levels that could indicate whether the animals were under psychological or nutritional stress, or both.
Deer were found to make up 80 percent of wolves’ diet, with caribou and moose each accounting for about 10 percent. Moose favored habitat associated with food and didn’t seem particularly concerned about people. The result was that their scat had low levels of stress hormones and high levels of nutrition hormones. But caribou proved to be much more skittish. They chose open, flat areas where, presumably, they could see and hear predators and escape. That also made it easier for them to see and hear humans on the landscape. Their scat reflected high stress and low nutrition in areas nearer roads when humans were most active. It turned out that wolves mostly favored areas inhabited by their favorite food source, deer, which also is habitat with few caribou.
Removing wolves could actually have unintentional consequences, Wasser says, because with a much-reduced wolf population, the number of deer would probably increase rapidly. The deer could alter the habitat and perhaps reduce the caribou food supply. Deer also carry multiple diseases that could jump to the caribou population. Until there is evidence to the contrary, changing human activity patterns is safer, he says.
Posted by Amanda Graham – 1 July 2011; 1:22:02 AM – Permalink
Tagged: Arctic, News, Polar research: Reports and findings