Use of highway underpasses by large mammals and other wildlife in Virginia: factors influencing their effectiveness

  • Published source details Donaldson B. (2007) Use of highway underpasses by large mammals and other wildlife in Virginia: factors influencing their effectiveness. Transportation Research Record, 2011, 157-164.


This study is summarised as evidence for the following.

Action Category

Install tunnels/culverts/underpasses under roads/railways

Action Link
Reptile Conservation

Install tunnels/culverts/underpass under roads

Action Link
Terrestrial Mammal Conservation
  1. Install tunnels/culverts/underpasses under roads/railways

    A replicated study in 2004–2005 along seven roads in Virginia, USA (Donaldson 2007) found that underpasses (including areas under bridges) were used by black rat snakes Pantherophis obsoletus. Black rat snakes were observed using at least one of the underpasses (data not provided). In June 2004–May 2005, seven underpasses (including the area under two bridges) were monitored using a camera at each entrance and exit. Photographs were downloaded once a week. Most of the underpasses were designed for water drainage.

    (Summarised by: Katie Sainsbury)

  2. Install tunnels/culverts/underpass under roads

    A study in 2004–2005 at seven sites along roads through forest in Virginia, USA (Donaldson 2007) found that white-tailed deer Odocoileus virginianus used underpasses to cross the road but black bears Ursus americanus did not. White-tailed deer crossed through four of seven underpasses monitored, with a total of 1,107 crossings detected. Black bears approached one underpass entrance three times, but did not cross through. Other mammals recorded in underpasses included opossums Didelphis virginiana, bobcats Lynx rufus, red foxes Vulpes vulpes, coyotes Canis latrans, raccoons Procyon lotor and groundhogs Marmota monax as well as squirrels and mice (see paper for details). Seven underpasses were monitored. Five were culverts (1.8–6.1 m wide, 1.8–4.6 m high and 21–79 m long). Two were crossings under bridges (13–94 m wide, 5–14 m high and 10–18 m long). Underpasses were not fenced and most had a narrow water section. Underpasses were monitored from June 2004 to May 2005, using one or two camera traps at each entrance.

    (Summarised by: Ricardo Rocha)

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