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Providing evidence to improve practice

Individual study: Evaluation of deer-exclusion grates in urban areas

Published source details

Peterson M.N., Lopez R.P., Silvy N.J., Owen C.B., Frank P.A. & Braden A.W. (2003) Evaluation of deer-exclusion grates in urban areas. Wildlife Society Bulletin, 31, 1198-1204


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Install wildlife exclusion grates/cattle grids Terrestrial Mammal Conservation

A replicated, before-and-after study in 2001 in Florida, USA (Peterson et al. 2003) found that one of three deer exclusion grates excluded Florida Key deer Odocoileus virginianus clavium. Only one deer crossed the grate that incorporated diagonal cross members into the metal grid, compared to 305 that crossed when the grate was covered over with plywood. Fifty deer crossed the two grate designs without diagonal cross members, compared to 199 that crossed when covered over. Males were more successful at crossing than females. In 2001, three types of grate were tested for deer-exclusion efficiency. All grates were 6.1 × 6.1 m, each with a different grate pattern: grid of 10 × 13 cm rectangles with diagonal cross member through each rectangle and 8 × 10 cm or 10 × 8 cm rectangles without diagonal cross member. Food was provided within a fenced area accessible only by crossing the grate. Grates were covered (therefore, easily crossable) for 1–2 weeks and then uncovered for one week, three times (for two designs) or once (third design). Infra-red cameras were used to monitor deer crossings.

(Summarised by Rebecca K. Smith)