Amfibieëntunnels voor ringslangen, een goed idee?

Amphibian tunnels for grass snakes,a good idea? Roads that disrupt migration routesfor amphibians are often mitigated by the installation of tunnels. This was also done at the Westerbergweg in Wageningen, the Netherlands, which is situated on the transition of river foreland and glacial deposits. Discussion arose whether these tunnels and the drift fences could possibly be barriers for grass snake migration. By means of sand tracks we therefore monitored the movement of grass snakes through two semi-open amphibian tunnels (type Aco AT500).The field work was conducted between April and October in 2006 and 2007.A total of 46 grass snake tracks were found in the tunnels during 312 control days. Although tunnel acceptance by grass snakes was proven, the tunnel/fence system did not significantly reduce road kills (Kolmogorov-Smirnovtest; P>0,05). After installation, small but quite similar numbers of grass snakes as those prior to the installation were still killed by traffic. This is probably due to the inappropriate fencing which should prevent snakes from reaching the road and guide them towards the tunnels. also done at the Westerbergwegin Wageningen, the Netherlands,which is situated on the transition of