Effective Wildlife Fences Through Better Functioning Barriers at Access Roads and Jumpouts

The objectives of this project are to investigate the effectiveness of relatively low-cost electrified barriers that are aimed at keeping carnivore species, especially black bear and grizzly bear, out of fenced road corridors at access roads with very low traffic volume and very low traffic speed, and to investigate the effectiveness of modifications of jump-outs aimed at allowing white-tailed deer and mule deer to escape the fenced road corridor more readily, while continuing to discourage deer from jumping up into the fenced road corridor.

The reconstruction of 56 miles (90 km) of US Hwy 93 N on the Flathead Indian Reservation included the installation of wildlife crossing structures at 39 locations and approximately 8.71 miles (14.01 km) of wildlife exclusion fence . Wildlife guards (similar to cattle guards) at access roads have proven to be a substantial barrier to deer species (about 80% to nearly 100% barrier) but unfortunately, they are quite permeable to carnivore species, including bear species . In addition, animals that end up inside, between the fences must be able to escape quickly. Earthen mounds (jump-outs) are designed to allow animals to jump down to the safe side of the fence. However, deer use of wildlife jump-outs has been low along US Hwy 93 N (only about 32% use by mule deer, only about 7% use by white-tailed deer). This means that these animals spend more time inside the fenced road corridor before they exit, either at one of the jump-outs or at a fence-end. To further improve human safety, and to reduce direct road mortality of wildlife, including grizzly bears, additional measures are needed at access roads, and deer species need to be able to use the jump-outs more readily.

Electrified barriers have been implemented at high-volume access roads and at fence ends of high-volume highways in the United States and other countries. However, electrified wildlife guards or electrified mats or electrified metal strips embedded in the main travel lanes and at high-volume side roads can cost tens of thousands up to hundreds of thousands of dollars per location. In practice, many access points along a fenced highway in a multi-functional landscape have very low traffic volume and very low traffic speed (e.g. access to an agricultural field). Relatively inexpensive electrified barriers (e.g. up to several thousands of dollars per location) may be suitable for such low traffic volume and low traffic speed access roads. Of course, these low lost barriers must still be effective in keeping large mammals, including bear species, out of the fenced road corridor. This research project focusses on electrified barriers that are relatively low cost and that appear suited for low traffic volume and low traffic speed locations.

The results of this project will provide information on how keep wildlife out of fenced road corridors through electrified barriers at access roads, and on how to improve deer use of wildlife jump-outs, should they still end up in between the fences.