Providing evidence to improve practice

Individual study: Mammals were recorded in all and amphibians in 77% of 53 wildlife passages monitored in the Netherlands

Published source details

Veenbaas G. & Brandjes J. (1999) Use of fauna passages along waterways under highways. Proceedings of the International Conference on Wildlife Ecology and Transportation, Florida Department of Transportation, Tallahassee, 253–258.


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

Install culverts or tunnels as road crossings Amphibian Conservation

A replicated study in 1997–1998 of 53 wildlife passages along waterways under roads at over 20 sites in the Netherlands (Veenbaas & Brandjes 1999) found that 77% of passages were used by amphibians. Amphibian tracks were recorded in 19–22 passages/year. There was no relationship between use and passage width or substrate. Culverts and bridges were adapted for wildlife in the 1990s in the Netherlands. In 1997, 31 passages (0.4–3.5 m wide) were monitored. These included extended banks (unpaved or paved), planks fixed on bridge or culvert walls, planks floating on the water, concrete passageways and plastic gutters covered with sand. In 1998, 22 passages were monitored for the effect of width and substrate. These were wooden passageways fixed on a bridge or culvert wall (0.2–0.6 m wide). Monitoring involved weekly checks of tracks on sandbeds (for 4–7 weeks) and ink pads (12 weeks in 1997, four weeks in 1998) across passageways.