Individual study: Managing mountain goats at a highway crossing
Singer F.J. & Doherty J.L. (1985) Managing mountain goats at a highway crossing. Wildlife Society Bulletin, 13, 469-477
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Install barrier fencing and underpasses along roads
A before-and-after study in 1975–1981 in Montana, USA (Singer & Doherty 1985) found that two underpasses and roadside fencing increased highway crossing success by mountain goats Oreamnos americanus. After construction, 90% of highway crossing attempts were successful compared to 86% during and 74% before construction (unsuccessful attempts were when the crossing was temporarily thwarted). Crossing hesitations and run-backs decreased by 80% after underpass construction, delay time before crossing declined by about 30% and signs of fear (measured by an index) decreased. All crossings were successful when there was no disturbance, but success decreased to 85% when humans or traffic were present. A large underpass (3–8 m high, 23 m wide, 11 m long) was constructed where goats were observed crossing. In addition, a new road bridge included a ledge underneath for goats to cross (3 m high, 3 m wide, 11 m long). A sheer wall downhill and barrier fencing prevented goats crossing between underpasses. Old goat trails were removed and new trails to underpasses dug. Goat crossings were monitored before (1975), during (May–October 1980) and after underpass construction (October 1980–September 1981).
(Summarised by Rebecca K. Smith)