Wildlife fencing at German highways and federal roads – requirements and management implications

Abstract

In Germany, the high risk of wildlife–vehicle collisions (WVC) is further increasing due to increasing traffic volumes and road densities as well as the growing population densities of common ungulate species. As a result, threats to human health and property as well as wildlife mortality of widely spread and rare species increase. Currently, three basic types of wildlife fences are used in Germany: type A, a conventional galvanized‐high tensile deer fence (made of knot braid); type B, a chain wire (mesh wire) fence; type C, a rigid welded wire mesh fence panels. Since fencing needs to restrict access of many different species with different behaviours (e.g. jumping, climbing, digging), fencing needs to be multifaceted to be effectively. Furthermore, the occurrence of wildlife species with habits such as jumping, climbing or digging determines the optimal (functional) fence design per location. We surveyed road managers in combination with a personal assessment of road sections in Germany and derived the following recommendations for optimal fencing to reduce WVC: 1) To deter digging, use plates made of recycled synthetic materials or a concrete foundation, instead of barbed wire. 2) Fencing should be made of chain wire (mesh wire, type B) fence or rigid welded wire mesh fence panels (type C) instead of knot braid mesh (type A). 3) To restrict climbing, use angled chain wire fence or rigid welded wire mesh fence panels at the top of the fences. 4) Maintain fences so that they are kept free from ingrown vegetation/woods. Maintenance conditions should be considered while planning and building the fence, especially to ensure sufficient space on both sides for accessibility. 5) Fencing should be established preferably near the roadside and moved away from property lines. In conclusion, wildlife fencing could be a very effective mitigation measure to prevent WVC with common as well as protected species, when proper designed and recommendations of the survey will be consequently considered. Currently many wildlife fences lack functionality due to an inappropriate design and maintenance issues in Germany.