This video says about itself:
2 August 2012
A picture essay of Wildlife Corridors from around the world.
It turns out these corridors are succesful for many kinds of wildlife:
A great success at both wildlife bridges is the so-called wet zone, an area with pools for amphibians. There are already eggs of common frogs found there and even a natterjack toad, a species which forester Mari de Bijl did not expect there. He also thinks that no wildlife viaducts should be allowed to be built without wet zones.