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Providing evidence to improve practice

Individual study: Mule deer behavior in relation to fencing and underpasses on Interstate 80 in Wyoming

Published source details

Ward A.L. (1982) Mule deer behavior in relation to fencing and underpasses on Interstate 80 in Wyoming. Transportation Research Record, 859, 8-13


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Install fences around existing culverts or underpasses under roads/railways Terrestrial Mammal Conservation

A before-and-after study in 1976–1981 along a highway through shrubland in Wyoming, USA (Ward 1982) found that after a fence alongside the highway that was connected to underpasses was made taller, fewer mule deer Odocoileus hemionus were killed. Results were not tested for statistical significance. In six migration seasons (three springs, three autumn–winters) after increasing the height of the fence, only one deer-vehicle accident occurred in the fenced area. In three migration seasons before fence construction (two spring and one autumn–winter), 53 deer–vehicle accidents occurred within the area to be fenced. The study was conducted along a stretch of highway constructed in late 1970. In 1977–1978, the height of a fence along the highway was increased from 4 ft to 8 ft along both sides of 7.8 miles of road. The fence allowed deer to access seven underpasses (length: 110–393 feet; width: 10–50 feet; height: 10–17 feet). Deer movement was monitored before (1976–1977) and after (1978–1981) fence heightening by direct observation, track counts, radio-tracking and automatic cameras. The highway was located across a migration route of 1,600–2,000 mule deer.

(Summarised by Ricardo Rocha)

Install barrier fencing and underpasses along roads Terrestrial Mammal Conservation

A study in 1977–1979 along a highway through shrubland in Wyoming, USA (Ward 1982) found that underpasses, in areas with roadside fencing, were used by mule deer Odocoileus hemionus to cross under the road. During four migration periods (two spring, two autumn–winter) immediately after underpasses were connected to a fence, >4,000 crossings through underpasses were made by deer (precise figure not stated). The study was conducted along a 7.8-mile stretch of highway constructed in late 1970. The highway was located on a migration route of 1,600–2,000 mule deer. Over four migratory periods, seven underpasses (length: 110–393 feet; width: 10–50 feet; height: 10–17 feet) were monitored for deer use. Underpasses were connected to 8-foot-high roadside fencing that guided animals towards entrances. From 1978, an attempt was made to attract deer to six of the seven underpasses by baiting with alfalfa hay, supplemented with apple pulp or by vegetable trimmings. Deer movements were monitored by track counts and surveillance cameras.

(Summarised by Ricardo Rocha)