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Providing evidence to improve practice

Individual study: Seasonal and regional animal use of drainage structures to cross under roadways

Published source details

Sparks J.L. & Gates J.E. (2017) Seasonal and regional animal use of drainage structures to cross under roadways. Human Wildlife Interactions, 11, 182-191


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

Install tunnels/culverts/underpass under roads Terrestrial Mammal Conservation

A replicated study in 2008–2011 of 265 culverts throughout Maryland, USA (Sparks & Gates 2017) found that culverts were used by a range of mammal species to cross roads. Crossings were made by northern raccoons Procyon lotor (0.79/culvert/day), Virginia opossums Didelphis virginiana (0.03/culvert/day), woodchucks Marmota monax (0.03/culvert/day), red foxes Vulpes vulpes (0.03/culvert/day), eastern gray squirrels Sciurus carolinensis (0.02/culvert/day) and both common gray foxes Urocyon cinereoargenteus and white-footed mice Peromyscus spp (0.01/culvert/day). Between August 2008 and January 2011, a total of 265 randomly selected culverts were monitored using camera traps for a total of 31,317 camera-trap days. Culverts were located under paved roads and contained either a waterway, a route for water flow, or other depression. Culverts averaged 2.4 m wide, 1.9 m high and 46.4 m long. Each culvert was sampled at least nine times in 2008–2011, for 10–36 days each time, using one camera trap. The camera was placed at the approximate midpoint of the culvert or near the entrance.

(Summarised by Ricardo Rocha)