New research published in the journal Behavioral Ecology has carried out the first-ever systematic analysis of wolf ambushing behavior, and the results have revealed new insights into these intelligent predators and the total lack of hazard perception skills among beavers. As part of a growing body of work from the Voyageurs Wolf Project, this new study continues to overturn long-held ideas as to how wolves hunt, showing that they’ve got more tricks in their arsenal than simply outrunning and exhausting their prey.
While pack hunting for large animals like moose and bison is common in winter, wolves in the dense boreal forests in North America and Eurasia capitalize on food availability in summer by hunting beavers on their own. As the video below demonstrates, beavers don’t have the best eyesight when it comes to spotting wolves-in-waiting, but an animal that spends so little time on land is still not an easy kill. So, how do the wolves do it?
Over 15,000 hours of field research and 962 attempted predation events later, the team had their answer. Of the total number of successful beaver hunts (214), 89-94 percent of the ambushing sites were downwind meaning the beavers had a very slim chance of picking up the wolf’s scent. What beavers lack in vision they make up for with their noses and ears, and previous studies have shown they use scent to keep a (figurative) eye out for predators. While most of the observations didn’t put beavers on the menu, this isn’t to say that most wolves were terrible at hunting them.
“We suspect that at most of these ambushing attempts, wolves never even encountered a beaver,” said lead author on the paper Dr Thomas Gable in an email to IFLScience. “Predicting where beavers will be on land at any given time is challenging and we suspect that wolves often waited in areas and never had a beaver come near.”
"Wolf, what wolf?" - Beaver, 2021.
When hunting beavers, it seems that the wolves appreciated that patience is a virtue as many would lay in wait for anywhere from four to 12 hours for a beaver to appear, with one determined wolf waiting for an incredible 30 hours. But when it comes to this particular breed of prey, success isn’t as simple as the element of surprise.
“While beavers might seem like easy prey to catch and kill, that is far from the truth," Gable said. “Killing a beaver once it is on land is no easy feat. Beavers are basically football-shaped hunks of muscle with an incredibly powerful bite and sharp teeth. Not to mention, beavers rarely go far from water. All beavers need to do to evade a wolf is reach the water.” This, Gable explained, is a likely second contributor to the large number of failed ambush attempts.
In winter, these beavers can rely on a protective shield of ice to keep them safe from the wolves but in summer they represent supplementary sustenance that the wolves can take down without the rest of the pack. Having access to smaller animals like beavers and deer means they don’t need so much backup and hunting alone yields more nourishment compared to group efforts. The wolves Gable studies actually spend more time hunting alone than in packs. This demonstrates that the benefits of being responsible for your food supply outweigh the costs of having to share your catch with others, but the results of this cost-benefit-analysis will change with the seasons.