Wolves affect wetland ecosystems by killing beavers dispersing from their colonies to create new ponds.
And while that’s no surprise when considering the logic, the long-term effect could be substantial and ought to be studied, said one of the authors of a new paper published by researchers with the University of Minnesota’s Voyageurs Wolf Project and Voyageurs National Park.
The journal “Science Advances,” published a paper by project biologists and co-authors Tom Gable and Austin Homkes who found that 84 percent of newly-created and recolonized beaver ponds remained occupied by beavers for more than one year. But when a wolf kills the beaver that settles in a pond, no such ponds remain active.
This relationship between wolves and dispersing beavers shows how wolves are intimately connected to wetland creation across the boreal ecosystem and all the ecological processes that come from wetlands, Gable told The Journal Monday.
He noted that wolves can have this impact on wetlands without necessarily changing the abundance or behavior of beavers.
“Part of their role in the ecosystem is, at times, altering where beaver are building ponds, and whether or not that is substantial over long periods of time, we don’t know,” Gable said. The project estimates that wolves altered the establishment of about 88 ponds per year in the 2,000 square kilometer area being studied.
That means an impact to about one pond for ever 21 square kilometers per year, he said.
“The question becomes over a longer period of time, does that effect become more noticeable?” he wonders.
He said in a 5- or 10-year period, the impact to 400 or 800 beaver ponds, or where they would have been created, impacting a pond every 4 or 2 square kilometers, could be significant.
“That wolf appears to prevent beaver from turning streams and forested areas into ponds — I don’t this will come as any big surprise to people, it’s very straight forward — the logic makes sense, but that’s the beauty: (The effect) remains unknown, but it’s so simple in many respects,” he said.
The information has been gained over the five years of the VNP Wolf Project, the groundwork for which began in 2012, when Voyageurs National Park biologists began to monitor the wolf population, following delisting as a federally protected species.
Gable joined the project as a graduate student in 2015, when additional scientists came on board to consider wolf behavior, and predator behavior in particular, said Steve Windels, VNP biologist.
Windels said the park’s interest in the study is twofold: Gaining knowledge about wolf behavior in and of itself is valuable, and knowledge may play a role in the park’s management; and to highlight the role national parks play in scientific studies.
“National parks are national laboratories,” he said. “In some ways, how Voyageurs National Park looks now is the window into what this part of the world might have looked 500 years ago.”
Meanwhile, the recent finding adds more questions the project’s team would like to answer.
Specifically, Gable said he’d like to know more about the long-term effects to the ecosystem of the wolf-beaver predation connection.
However, the project relies greatly on funding and one source, the Legislative Citizens Committee on Minnesota Resources, has not yet been awarded.
Money earmarked for the project, and other projects in Borderland, has not been allocated by the Legislature from the state’s Environment and Natural Resource Trust Fund as recommended by the Legislative Citizens Commission on Minnesota Resources.
Rep. Rob Ecklund of International Falls, is a member of the LCCMR and called getting the money to the projects “a lesson in frustration.”
He said a bill allocating the money should be among the first items on the agenda for the 2021 session.
Attempted a bill at one of the six special sessions held this year came to no avail, he said, adding that a VNP beaver project, Ranier dock project, and others that would create jobs and add money to the economy are being held up.
Gable said project members are not optimistic that the LCCMR funding will come through. “We are very close to being out of funding,” he said. “We are scrambling.”
He said he may go without pay for a while, but the project is worth it.
“I am going to stick around until the bitter end,” he said. “It’s a once in a lifetime opportunity.”
People who would like to support the project or learn about it should see the VNP Wolf Project Facebook page.