[Ecological barrier effects of highways on mammals living in the wild--an animal welfare problem].

In the course of may 1992 to April 1993, ecological barrier effects to the Hanover-Berlin Autobahn (Germany) on mammalian wildlife were investigated. In this period 1566 carcases of various species were found on the road. Traffic volume showed an increase of 600% from 1989 (15,000 cars/24 hr) to 1992 (90,000 cars/24 hr). Wildlife use of 13 highway underpasses was monitored by video camera and countline checkpoints. Though they had various dimensions nearly all underpasses investigated were used by mammalians at least by fox, rabbit or marten. Because of the knowledge of the locations both of the maxima points of road mortality of wildlife and their use of controlled underpasses on is able to give recommendations for optimal localisations and dimensions of buildings which makes the wildlife able to pass the traffic line. The investigation proofs that the amount of wildlife killed on roads in Germany has been underestimated about 2000%. The problem of "just" wounded but not instantly killed animals while having an accident is pointed out as a severe problem from the animal welfare's point of view.