Is That Fence Wildlife Friendly?

Fences that Work for People and Wildlife by Leigh RobertsonA part of me cringes when I see old, unnecessary barbed wire or woven fences that haven’t been removed. It’s probably because I’ve seen too many gruesome photos of wildlife killed by fences.A study in Utah and Colorado showed an average of one deer, elk, or pronghorn tangled for every 2.5 miles of fence. In addition to getting tangled, hooved mammals may get blocked and stranded by some fences. The same study revealed one ungulate found dead next to every 1.2 miles of fence.In certain weather and lighting conditions, fences are invisible to wildlife. Elk sometimes knock over fences, which can pose problems for ranchers and horse owners. By marking fences to make them more visible, this is less likely to happen.Fences also pose hazards to birds. A researcher in Idaho found 111 sites where birds collided into fences in random samples of 80 miles of fence. Sage-grouse accounted for 86 of those mortalities. The good news was that marking fences with 3-inch pieces of vinyl reduced grouse fence collisions by 74 percent.So what can we do to reduce the deaths that fences cause to wildlife? Here are some ideas:

  • Remove your unnecessary fences
  • Make fences that you do need more wildlife-friendly—see below and CPW's informational booklet (Note: this practical guide has some photos that aren’t for the squeamish on pages 3, 5, 8, 31, and 36)
  • Mark fences to reduce wildlife collisions, see how you can do it here.
  • Get involved in, or donate to Sheep Mountain Alliance to help us continue our work to protect Colorado wildlife and wildlife habitat.

An Ideal Wildlife Friendly FenceWildlife friendly fences should be low enough for adult animals to jump, high enough for animals to crawl under, and minimize the chance of tangling. Experts recommend:

  • A top wire or rail preferably no more than 40” above the ground, and absolutely no more than 42”
  • At least 12” between the top two wires
  • At least 18” between the bottom wire or rail and the ground
  • Smooth wire or rail for the top, smooth wire on bottom
  • No vertical stays
  • Posts at 16.5-foot intervals
  • Gates, drop-downs, or other passages where wildlife concentrate and cross.

(From: Paige, C. 2008. A Landowner’s Guide to Wildlife Friendly Fences. Landowner/Wildlife Resource Program, Montana Fish, Wildlife and Parks, Helena, MT. 44 pp.)

WILDLIFELexi