Leave It to the Beavers

As Madison endures a long, hot summer of drought and wildfire haze, maybe it’s time to embrace what beavers have to offer.

These industrious hydrologic engineers are champing at the sticks to restore the 50% of Wisconsin wetlands that were drained for farming, including much of Madison’s isthmus. Their ponds slow flooding during rainy seasons, store water for times of drought, create a swampy barrier against wildfires, and build habitat for other species ranging from woodpeckers to fish to amphibians. 

Because of beavers’ documented ability to mitigate climate change, western states are encouraging beaver populations, and protecting them with new laws. In June, California declared beavers a “keystone species,” Seattle has installed pond levelers so beavers can build dams in its parks without flooding them, and groups such as the SLO Beaver Brigade document the health of local populations.

Europe, where beavers were wiped out during the craze for beaver skin hats, is restoring beavers into wetlands from Scotland to Russia. And with a documentary called The Beaver Believers, and the publication of two recent books extolling their virtues — Beaverland by Leila Philip and Eager by Ben Goldfarb — beavers are having their moment of fame.

Except, not so much in Wisconsin.

“We’re the only state that has a budget to destroy beavers; we’ve spent $15 million in the last 20 years to kill beavers,’’ says Bob Boucher, who claims the Wisconsin Department of Natural Resources is pursuing “a policy of beaver holocaust.” In the past decade, Boucher says U.S. Department of  Agriculture Wildlife Services statistics indicate that federal and state policies have killed 28,141 Wisconsin beavers and blown up or destroyed 14,796 beaver dams through hand removal or explosives, accidentally killing 1,091 river otters in the process.

“In blowing up 14,000 dams, that is 14,000 wetlands that they have destroyed, which is bizarre considering they’re supposed to be the environmental watchdogs,’’ Boucher says.

DNR spokespeople declined to comment, citing pending litigation.

In Madison, some Tenney Park neighbors were surprised to find a trapper working in the park last winter. Ann Shea, of the Madison Parks Department, says that two beavers were live-trapped and relocated from Tenney Park because of the damage they were doing to park trees; four more beavers were trapped last year at Yahara Hills, where they were flooding the golf course.

“For the most part, we tolerate beavers in natural areas through the park system,’’ Shea says, noting that beaver populations exist in Cherokee Marsh and the Paunack Marsh near Lake Monona’s outlet.

But Midwestern attitudes may be changing and there are moves afoot to rethink beaver management. Boucher’s group, Superior Bio-Conservancy, filed notice in late June that it intends to sue the wildlife services division of the USDA, which carries out the DNR’s orders to remove beavers along 1,800 miles of trout streams in Wisconsin. Boucher, who was co-author of a 2021 study that proposed using beavers to build $3.3 billion worth of flood-proofing along the Milwaukee River watershed, says he’s made 17 requests to meet with the DNR on its beaver policy, only to be rebuffed. 

“I hope that a stern talking-to from a judge may get them to pay attention,’’ he says.

And beavers in northern Wisconsin trout streams will be the topic of the annual trout stream improvement workshop Aug. 15, co-sponsored by the DNR and UW-Stevens Point. Another Midwest beaver and trout management conference, sponsored by the American Fisheries Society, is set for a week later in Grand Rapids, Michigan. 

Dynamiting beaver dams to “improve” streams for trout has long been a DNR policy.

Trout biologist Ray White, who will be a speaker at the August event in Hayward, grew up in Madison and remembers watching a nature movie at the Wisconsin Historical Society in the 1940s that showed game wardens ridding Wisconsin of beavers to encourage trout.

“I knew even as a kid that Wisconsin wanted to remove beavers,’’ says White, who worked at the Wisconsin DNR before going on to faculty positions at Michigan State and Montana State. “And then I became a biologist and I became involved in it. We felt beavers were messing up our work.”

Today, White, 88, sees the issue as less clear cut. Eastern brook trout, Wisconsin’s native species, and beavers evolved together in Wisconsin. While trout improvement dogma declares that beaver dams cause trout streams to warm up and silt up behind the dams, White says that isn’t necessarily a problem for trout spawning.

“It turns out that eastern brook trout spawn where groundwater comes up through the gravel, they seek out places where they can feel the upwelling water,’’ he says. “If the silt is thin enough at the edge of a beaver pond, they can still spawn there.”

Still, White doesn’t oppose removing beavers from trout waters, saying, “we don’t need beavers everywhere.”

Another workshop speaker Emily Fairfax, a hydrologist at the University of Minnesota, says that her research shows that beaver dams can have a beneficial effect, forcing moving water downwards, where it mingles with chilly groundwater and remerges much colder.

“I’ve felt this, walking down beaver-dammed streams, and suddenly you’ll feel this ice cold stream of water coming up,’’ Fairfax says. “So beaver ponds will have super cool pools that trout love, warmer pools that turtles and amphibians love, there’s something for everyone in this habitat. Beavers are really, really good at creating these biodiversity hotspots.”

Fairfax, who did her beaver research in California and other western states, says Wisconsin lacks solid data on its beaver populations because the DNR does not track the number of beavers killed by private landowners. (In his complaint, Boucher notes the USDA wildlife services kills three times more beavers per year than planned in its 2013 environmental assessment plan.)

“There needs to be a way to track the actual population because they reproduce slowly, they only have one litter of kits a year and only half will survive to adulthood,’’ Fairfax says. “Beavers won’t reproduce under stress, they’re not like other rodents that reproduce quickly.”

Another thing Wisconsin could do, she says, is get rid of a state law that makes it legal to go onto a neighbor’s property and destroy a beaver dam. Fairfax understands that some landowners don’t enjoy the aesthetics of a swiftly moving stream being converted by beavers into a murky swamp.

“We have what I call ‘ecological amnesia,’ because it’s been 200 or 300 years since beavers were really abundant,’’ Fairfax says. The first Europeans who arrived in Wisconsin were fur traders, and they encountered a wet, paleo landscape of braided streams that would flood during wet seasons and contract during dry times.

When the French explorer Daniel Greysolon, Sieur du Lhut, began bushwhacking his way up the Brule River in 1680, looking for a connection between Lake Superior and the Mississippi, he also found lots and lots of beavers. The namesake of Duluth reported that he smashed through at least 100 beaver dams before reaching Upper Lake Saint Croix.

Based on her California experience, Fairfax says it may take a lawsuit to get Wisconsin’s beaver believers working with the trout fanciers. It also may take a climate-fueled disaster or two.

“The West was confronted with climate disasters much sooner, and those are situations where you really see the benefits of beavers,’’ Fairfax says. “If we want to be climate resilient, we need more wetlands, and beavers are great builders of wetlands.” 

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