Individual study: Behavioral response of mule deer to a highway underpass
Reed D.F., Woodard T.N. & Pojar T.M. (1975) Behavioral response of mule deer to a highway underpass. The Journal of Wildlife Management, 39, 361-367
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 1970–1973 along a highway in Colorado, USA (Reed et al. 1975; same experimental set-up as Reed 1981) found that an underpass, in areas with roadside fencing and one-way gates, reduced road mortalities and allowed most local mule deer Odocoileus hemionus to migrate safely under a highway. There were 14 deer-vehicle accidents/year within the fenced section compared to 36/year before installation of the underpass and fencing. On average, 345 mule deer (61% of the local population) used the culvert each season, with up to 17 crossings/day. Underpass use was not affected by artificial lighting. On average, 17% of deer used one-way gates to escape the highway and 17% went round the ends of fences or did not cross. In 1970, a concrete box underpass (3 × 3 × 30 m, with two skylights) was installed under a 3.2-km section of highway. The 2.4-m-high barrier fencing either side had eight one-way gates. Underpass-use was monitored by track counts and mechanical counters daily and a video camera at night during spring–summer and autumn migrations in 1970–1973. Artificial lighting was alternately turned on and off over 28 nights, in June and October 1973. Tracks at gates and deer movements along the fence were monitored each morning.
(Summarised by Rebecca K. Smith)