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Providing evidence to improve practice

Individual study: Evaluation of road expansion and connectivity mitigation for wildlife in southern California

Published source details

Alonso R.S., Lyren L.M., Boydston E.E., Haas C.D. & Crooks K.R. (2014) Evaluation of road expansion and connectivity mitigation for wildlife in southern California. The Southwestern Naturalist, 59, 181-187


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 Terrestrial Mammal Conservation

A study in 1997–2009 along a major road in California, USA (Alonso et al. 2014) found that all 19 culverts under the road (most of which were in areas with roadside fencing) were used as road crossing points by coyotes Canis latrens, bobcats Lynx rufus, and mule deer Odocoileus hemionus. Coyotes used 18–19 of the 19 culverts studied, and bobcats used 13–19 culverts. Mule deer used 1–4 of the five underpasses considered suitable for them. Ranges represent the numbers of culverts used in each of two survey periods. Sixteen culverts were part of a road upgrade programmme, conducted in 2005, that included installation of 3-m-high roadside fencing. From November 1997 to January 2000, remotely triggered cameras were placed in each culvert. Cameras were again placed in each culvert from August 2008 to September 2009. Between the two surveys, the road network was expanded and adjacent habitat was restored.

(Summarised by Phil Martin)