Providing evidence to improve practice

Individual study: Assessing the effectiveness of amphibian mitigation on the Sea to Sky Highway: passageway use, roadkill mortality, and population level effects

Published source details

Malt J. (2011) Assessing the effectiveness of amphibian mitigation on the Sea to Sky Highway: passageway use, roadkill mortality, and population level effects. Herpetofauna and Roads Workshop - Is there light at the end of the tunnel? Vancouver Island University, Nanaimo, Canada, 17-18.


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 along roads Amphibian Conservation

A controlled study in 2009 of wildlife culverts with barrier fencing along a new highway through wetlands near Whistler, Canada (Malt 2011) found that drift-fencing or barriers directing amphibians towards culverts significantly reduced road-kills. Road-kill rates were reduced by over 50% along road sections with ≥ 50 m of drift-fencing or barriers compared to those with no barriers (2–8 vs 15–17 killed/50 m section). Additional fencing was therefore installed. Eight wildlife culvert underpasses were constructed along the section through the wetland. Drift-fences were installed to funnel animals towards culverts. Barrier walls were also installed to prevent migration along some sections. Amphibians were monitored using road-kill surveys, remote cameras at culvert entrances and a mark‐recapture study of red‐legged frogs Rana aurora.

 

Install culverts or tunnels as road crossings Amphibian Conservation

A controlled study in 2009 of wildlife culverts along a new highway through wetlands near Whistler, Canada (Malt 2011) found that road-kill rates were reduced provided that drift-fencing or barriers were installed to direct animals towards culverts. Road-kill rates were reduced significantly (by over 50%) along road sections with ≥ 50 m of drift-fencing or barriers compared to those with no barriers (2–8 vs 15–17 killed/50 m section). Approximately 400–500 amphibians were still killed annually along the new highway. Amphibians appeared hesitant to use culverts. Eight wildlife culvert underpasses were constructed along the section through the wetland. Drift-fences were installed to funnel animals towards culverts. Barrier walls were also installed to prevent migration along some sections. Amphibians were monitored using roadkill surveys, remote cameras at culvert entrances and a mark‐recapture study of red‐legged frogs Rana aurora.