IENE 2016

The loss and fragmentation of suitable habitats due to transport infrastructure is one of the key challenges for large animal species management. Usual measures for the prevention of animalvehicle collisions, like fences, often act as an additional barrier and are only appropriate in the case of long intersection-free motorways or railroads. Over- or underpasses are valid methods to reduce fragmentation effects, but these type of buildings is mostly very expensive to build and to maintain over years. In addition, the combination of fences and conventional wildlife-crossings is nearly unable to adapt to a changing habitat use of the target species and for some species they may be even counterproductive (e.g. cats).

The goal of our studies is the development of a risk-adapted management concept which makes use of an iterative assessment of the whole transport route to find the best measures to avoid collisions. This includes the use of different monitoring measures like wildlife track monitoring, snow tracking, camera traps or a survey of local experts. The second part of our research is the development of a new type of secured wildlife crossing, which addresses most of the disadvantages of traditional buildings. It should be usable on medium-class railroads in a landscape where it's not appropriate to build large crossing-structures.

For this purpose we developed a system of relatively short fences to guide the animals to narrow gaps which allow a nearly unrestricted crossing. To avoid a funnel-effect and more collisions at these gaps or at the end sections of the fences, we will use acoustic deterrent devices to chase away near standing animals in the case of an approaching train. These devices will act like an automatic boom barrier at level crossings for wildlife. This type of wildlife-crossing is highly adaptable to changes in the environment or habitat use, when noticed in the risk assessment. The main challenge is the arrangement of repellent effects in order to avoid a fast habituation of the target species. A basic requirement in our sample area is the effectiveness of the applied techniques on large herbivores like red and roe deer as well as carnivores like the wolf.

Therefore, the creation and application of suitable acoustic repellents is subject of studies in two different wildlife enclosures. Tests in a sample area along a renewed railway section will follow. By the described risk-adapted management concept we expect a significant reduction of animal-vehicle collisions along railway routes or even secondary roads, being not in the condition to be secured by long fences and additional over- or underpasses.