How Do Wolves and Beavers Interact in Boreal Ecosystems?

By Steve Windels, PhD, Voyageurs National Park Wildlife Biologist Voyageurs National Park is unique in that our park maintains a very high density of beavers in addition to white-tailed deer and moose that wolves like to prey upon.  Beavers are generally a ‘safer’ food source for wolves than deer or moose which can kick or gore an attacking wolf.

However, beavers have evolved behaviors to protect them from predation by wolves and other predators, such as constructing lodges with underwater entrances.  Given the importance of both wolves and beavers to Voyageurs National Park, how do these two species interact throughout the park and over the course of the year?  How do changes in the abundance of one species affect the other, and consequently affect other parts of the ecosystem like moose or beaver-created wetlands?

Voyageurs National Park staff in cooperation with Northern Michigan University (NMU) initiated a study in 2015 to answer some of these questions.  Tom Gable, a masters student at NMU working on the project, has been logging many hours this summer investigating wolf kill sites and collecting wolf scat as a means to understand wolf diet throughout the season.

Austin Homkes is a volunteer working closely with Tom.  Together they have collected more than 2000 wolf scats this summer - that is a lot of poop!  But the information they glean from these ‘scats’ and other information they get from kill sites will tell us a lot about how wolves hunt beavers, the role of wolves in regulating beaver populations, and the importance of beavers to wolf diet throughout the spring-summer-fall period when beavers are most vulnerable to wolves.  As part of Voyageurs National Park's wolf monitoring program, we plan to continue the work into the future to examine this fascinating and important dynamic.

A picture of a wolf bed where the wolf appeared to have curled up right next to this active beaver lodge. The bed is in the lower right corner.

Watch as a park researcher walks through a wolf-killed beaver site (only small traces of the beaver remain), discussing its significance. To date, 22 wolf-killed beaver sites have been located in the park area.

Project volunteer Austin Homkes recording information at a wolf kill site, June 2015.