When it’s snowing, wolves hunker down

Gray wolves (Canis lupus) are accustomed to the snowy landscapes of northeastern Alberta, Canada, but when snow is falling, they become less active, researchers found. The effect was especially clear at night when the wolves typically hunt.

For TWS member Amanda Droghini, lead researcher on the study published in PLOS ONE, the findings reminded her of anecdotal comments from her hunter friends. They never bother to hunt when it’s snowing, she said, because they never find any game. Her friends aren’t alone, it seems.

“Maybe it’s just that when snow is falling, nothing is moving so wolves are not encountering prey,” Droghini said.

As part of her master’s work at the University of Alberta, Droghini was studying the movements of 17 collared wolves near Fort McMurray. In addition to the data from the GPS collars, she also had an array of remote cameras trained on snow depth markers. The cameras were intended to track snow accumulations, but Droghini realized they also could be used to determine when snow fell.

Comparing data from before and after snowfalls, “we were able to see that on the night of a snowfall, wolves are traveling less and when they are traveling, they’re traveling slower,” she said. “There’s something about the snowfall itself that is causing wolves to stay still for a few hours.”

It didn’t appear to be the new accumulation. Droghini and her professor, University of Alberta Biodiversity Conservation Chair Stan Boutin, expected the wolves would stay hunkered down the day after the new snow, but that didn’t happen. “The very next morning or afternoon, wolves were returning to normal behavior,” she said. “It seemed that it was a response to the act of snow falling rather than anything else. Something about the falling snow was causing them to stay still.”

But what? Droghini can only guess. But because precipitation tends to clear the air column of the molecules that produce scent, wildlife may find it harder to smell, she said. That could make it harder for wolves to sense prey and harder for prey to sense predators.