A pass to allow pronghorn antelope Antilocapra americana through sheep fences, Wyoming, USA
This study is summarised as evidence for the following.
Install mammal crossing points along fences on farmlandAction Link
Install mammal crossing points along fences on farmland
A study in 1965 of grassland at a site in Wyoming, USA (Mapston et al. 1970) found that a modified pass based on a cattle grid design enabled passage by pronghorn antelopes Antilocapra americana whilst preventing escape of domestic sheep and cows. A total of 100 antelope were observed jumping across the grills, during five separate crossing events. Antelopes crossed grills at fence corners more than they crossed those along straight fences. A range of designs were trailed, the optimal being a 6-foot-long grill in a 5.5-foot-wide fence opening. The grill consisted of 13 bars at 6 inch-intervals. These were mounted on 10-inch-high timbers with earth ramps running up to both ends.