Making fences friendly to wildlife

2014-08-18T00:00:00Z Making fences friendly to wildlifeBy Rich Landers The Spokesman-Review The Billings Gazette
August 18, 2014 12:00 am  • 

Fences are not natural to wildlife.

Although Northwest critters have lived among fences for more than a century, they still run into them. They snag legs and other body parts on barbed-wire or metal posts. They detour around them and get ambushed by predators, bound over them and collide with vehicles, back away from them and go malnourished as their natural movements for food and cover are cut off.

Birds fly into wire and break their wings or necks.

Wildlife managers are removing as many fences from the landscape as they can to improve safety for wildlife on public lands throughout the region, but they also build fences to protect wildlife habitat from livestock and off-road vehicles.

However, years of research has produced protocols for better barriers.

"We try to make wildlife compatible fences," said Jason Lowe, wildlife biologists for the U.S. Bureau of Land Management's Spokane District. "In this region, most of the consideration is for deer and sage grouse."

BLM has adopted fencing guidelines from wildlife research conducted throughout the Western states, including specifications on the distance between the wires.

"For example, we have ranges for how high the bottom wire should be off the ground because a lot of times mule deer prefer to go under fences," he said.

The middle two wires are closer together to leave room for a larger space below the top wire, he explained. When deer jump over a fence, a leg sometimes hits the top wire. If the wire bounces and wraps on the next wire, the deer's foot can be snagged as if it were caught in a trap.

"Tight fences are safer than loose wires that tangle more easily," he said.

Barbed-wire fences tend to snag wildlife and rip their skin, but barbed wire definitely is more effective in keeping cattle out, he said.

"It's preferable that the top and bottom wires be smooth for wildlife going under or over the fence, while we use barbed wire in the middle to deter the cattle," Lowe said.

"But for fences that get a lot of pressure, like a fence along a riparian (streamside) area, we'll use barbed wire on top and smooth on the bottom only. Cattle will challenge a fence to get to green grass. If it's just a fence through a pasture that's the same on both sides, they don't bother it as much."

In areas of Lincoln and Douglas counties, where threatened sage grouse are being reintroduced, 2-inch plastic strips are clipped on the wires every 2 feet to make the fence more visible.

"Research in Utah led by the Natural Resources Conservation Service quantified the number of sage grouse killed on fences," Lowe said. "They're significant sources of mortality especially on the top of ridgelines and within a kilometer from where they congregate on their leks (mating grounds)."

High fences that prevent big-game passage have been installed by state agencies in several areas of Washington to steer elk away from conflicts with humans and agriculture.

A fence that can be seen from Interstate 90 near Ellensburg helps divert some elk from crop fields during winter on the Oak Creek Wildlife Area, where the Washington Department of Fish and Wildlife runs an artificial winter feeding program to keep the unusually large congregations of game from starving.

A deer-proof fence installed four years ago for $895,000 near Wenatchee has significantly decreased the number of winter wildlife-vehicle collisions on Highway 97A, according to the state Department of Transportation.

The 4.5-mile-long barrier north of Rocky Reach Dam protects motorists as well as deer and bighorn sheep.

A similar 8-foot-high fence is maintained in southeastern Washington along boundaries of the Umatilla National Forest and state-managed wildlife areas in the Blue Mountains Wildlife Area Complex.

"It starts on the Wooten Wildlife area at the Tucannon River and runs 26 miles to Asotin Creek to keep elk on public land and out of the agricultural fields," said Kari Dingman, assistant complex manager.

One-way gates are installed frequently along the fence to allow big game to pass onto state or national forest land but not go back to the private lands.

The fence requires annual maintenance. Blowdown trees often break portions of the fence.

"We use barbed-wire fences where we border private grazing land and in some cases we have fences to mark our boundaries," Dingman said. "In those cases, we use a smooth bottom wire."

But in most cases, Fish and Wildlife Department managers have their sights on removing fences inside the Wooten and other Blue Mountains wildlife areas.

"A lot of our wildlife areas are made up of homesteads that were purchased by the state," Dingman said. "A lot of fences and wire remains from where the pastures were fenced off. We come across wire we didn't know about when we're out doing projects.

"I've removed several miles of fence myself, and there's a lot more out there."

In late May, a crew of 11 volunteers organized by the Inland Northwest Wildlife Council devoted a weekend to removing barbed wire on the Wooten.

"They've been coming almost every year since 2008 and they've been a big, big help," Dingman said.

The group removed several miles of four- and five-strand barbed wire fence in the Tucannon Valley, said crew organizer Ken Hoff. "We had a lot of fun pulling steel T posts and untangling the barbed wire from a lot of brush, wild rose bushes and stickered Hawthorne trees," he said. "When I got home, I told my wife I had to fight off a mountain lion, there were so many scratches on my arms.

"All kidding aside, we had a good time and helped to make the landscape much more attractive and safer for wildlife to traverse without getting hung up in an unused fence."

Copyright 2014 The Billings Gazette. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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