New tool keeps beavers from causing damage

JACKSON, Wyo. — The industrious and persistent beaver doesn't always win the fight to reshape its landscape. And sometimes that's for its own good.

A mammoth native rodent prevalent through much of Wyoming, beavers can be a pest to landowners trying to maintain productive graze, keep roads dry or retain a stand of cottonwood. Historically, problem animals have been shot, trapped and killed en masse -both inside and outside of the law.

Drew Reed, executive director of the Wyoming Wetlands Society, is now providing the beaver-irked with another option.

The "beaver deceiver" is exactly what it sounds like. Reed's contraption, pioneered in Maine in the 1990s, regulates flow out of beaver ponds via a 12-inchwide pipe that penetrates the dam.

"Basically, the deceiver is set at the max water level acceptable for the situation," Reed said.

On the upstream side of the dam, Reed extends the pipe about 10 feet so the outlet isn't obvious. He also drills a bunch of holes into the pipe.

"Even if the beaver figures out the pipe, water still flows through the hundreds of holes," Reed said. "They really can't block the pipe."

Beaver torture? Indeed.

But Reed's technique is also helping to keep Jackson Hole's beavers alive.

On June 29, Reed and colleague Dave Dunlop installed a beaver deceiver on private property about a half-mile to the west of the Cache Creek trailhead in East Jackson.

This particular landowner came to Reed last fall in hopes of getting Wyoming Wetlands Society to remove the problem animals through its beaver relocation program. Initially, Reed was hesitant, because it was late in the year and ponds were beginning to ice up. The landowner's "only complaint was that the water table had risen to the point that the pasture was soggy," Reed said. "We realized that if we installed a deceiver, the beaver could stay."

There's a "fine line" between a pond that's deep enough for beavers to survive and shallow enough to not affect landowners, Reed said.

Because of this, relocation is the go-to arrow in Wyoming Wetlands Society's quiver. Since 2005, the nonprofit organization has "deceived" just twice, but relocated 140 animals.

Beavers taken from private property in the valley are moved to wetland areas in the Bridger-Teton National Forest. While Reed has never tracked the fates of the relocated rodents, a 2002 study from the Wyoming Cooperative Fish and Wildlife Research Unit analyzed just that.

The findings were grim. Only 23 of the 234 Wyoming beavers transplanted eventually built dams in the drainages where they were released. Without lodges to use for escape, many died quickly, whether from grizzly bears, coyotes or humans. The mortality rate for beavers younger than 2 years old was 100 percent within six months.

Beavers, it seems, just have it tough.

All things considered, it's safe to say that while the beavers subject to Reed's latest deceiver might be characteristically (and fruitlessly) busy, they're also lucky. "I realized I had finally come across a situation where it was ideal to try to live with beavers in an urban setting," he said.

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Information from: Jackson Hole (Wyo.) News And Guide, http://www.jhnewsandguide.com