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Providing evidence to improve practice

Individual study: White-tailed deer roadside behavior, wildlife warning reflectors and highway mortality

Published source details

Waring G.H., Griffis J.L. & Vaughn M.E. (1991) White-tailed deer roadside behavior, wildlife warning reflectors and highway mortality. Applied Animal Behaviour Science, 29, 215-223


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

Install wildlife warning reflectors along roads Terrestrial Mammal Conservation

A before-and-after study in 1977–1982 along a road through agricultural land in Illinois, USA (Waring et al. 1991) found that warning reflectors did not reduce deer-vehicle collisions. A similar number of white-tailed deer Odocoileus virginianus was killed overnight during a year with reflectors installed (six deer) as during the previous two years before reflectors were installed (5–6/year). The local deer population was reported to have decreased over this time. Behaviour of deer crossing the road or feeding at the roadside did not appear to be altered by reflectors. Eighty Swareflex wildlife warning reflectors were installed along each side of a 0.8-km section of a two-lane highway (speed limit 88 km/hour). Reflectors comprised two mirrors (5 × 17 cm) covered with red prism plates on posts 20 m apart, 3 m from the road edge. Collision data were provided by transportation personnel and direct observations.

(Summarised by Rebecca K. Smith)