Roadside exclusion fencing is commonly used to mitigate wildlife road mortalities as well as property damages caused by wildlife-vehicle collisions. A potentially lethal effect of exclusion fencing is that animals may become trapped on the roadside of the fence and unable to leave the right-of-way. On State Highway 100 in Cameron County, Texas, Texas Department of Transportation (TxDOT) modified segments of fencing to install ten wildlife exits as a solution that would allow animals to escape the roadway by exiting through a modified opening in the fence. However, in the initial design, some individuals learned to use the wildlife exits in reverse to enter the roadway within a year. In this study, a new design of wildlife exit was implemented, with narrower openings, a steep ramp and a clear plastic one-way door. The objectives of this study were to: 1) determine if the doors prevent animals from entering the roadway, 2) determine if the doors deter the animals from using the exit as intended, and 3) compare the percentages of animals that escape the roadway using the wildlife exits by study period. The new wildlife exits were monitored using camera traps, including a video camera attached to an infrared trip wire sensor to capture wildlife interactions. Logistic regressions were used to examine the effects of the door on animal movement between the road and habitat sides of the fence. This study will provide insights into use of wildlife exits designed for medium to small sized mammals and help to guide future designs that allow animals to escape roads with exclusion fencing.
wildlife crossing structure