A new report from the the Colorado Division of Wildlife said fences can pose serious threats to wildlife, even in urban and suburban areas.
Every year, thousands of big-game animals and birds die of injuries caused by fences.
“It’s difficult to imagine neighborhoods, farms, industry and ranches without fences,” wrote Wendy Hanophy, author of the report.
“They define property, confine pets and livestock, and protect that which is dear to us, joining or separating the public and private. For humans, fences make space into place. For wildlife, fences limit travel and access to critical habitat.”
Fences become problems when they are too high to jump, are too low to crawl under, have loose wires, have closely spaced wires, are difficult for animals to see or create a complete barrier.
“Deer, elk, moose, bighorn sheep and pronghorn are all capable of jumping many fences, but smooth or barbed wire can snag animals and tangle legs, especially if wires are loose or spaced too closely together,” Hanophy wrote. “If animals can’t pull free, they die a slow and desperate death.”
Fences that are too high can separate the young from their mothers. An adult female deer may be able to clear a fence, but juveniles can remain trapped on the other side, where they can be killed by predators or die of starvation.
Mammals aren’t the only fence-related casualties. Birds, waterfowl, in particular, collide with hard-to-see fences near waterways, causing broken wings, entanglement in wires or impalement by barbs.
Low-flying sage grouse frequently lose their lives to wire fences in sage brush habitat.
In urban and suburban areas, wildlife officials have found that animals often get hung up and die on decorative and wrought-iron fences.
“There are many creative ways to define boundaries, discourage trespass or maintain privacy,” Hanophy said. “A line of trees, shrubs or other vegetation can be used to mark a boundary, screen for privacy, beautify your landscape and provide additional food and cover for wildlife.”
In residential areas, Hanophy discourages the use of wooden fences that animals can’t see through, iron or steel fencing and chain-link fencing.
“These fences are especially dangerous to wildlife and can create a complete barrier to animals of all sizes, from turtles to moose,” she said.
For more detailed information on selecting and building wildlife-friendly fences, view the report, “Fencing with wildlife in mind,” at:
Utah research project
Good fences may — as the poet Robert Frost once wrote — make good neighbors, but University of Utah researchers found they can be killers for wildlife. The Utah researchers studied 600 miles of fence line in northeastern Utah and northwestern Colorado. Among their findings:
•Woven-wire fences topped with a single strand of barbed wire were most lethal to wildlife.
•One big game animal was found for every 2.5 miles of fence.
•One animal was found dead next to fences every 1.2 miles.
•Most animals died by getting caught in the top two wires while trying to jump.
•Seventy percent of all mortalities were on fences higher than 40 inches.
•Ninety percent of carcasses found near fences were of young animals that had been separated from their mothers.
