2025/06/10 by Michael Bräunicke, Roland Steiner, Jennifer Theobald +1 · 1 voice
Agricultural and Biological Sciences · Environmental Science · #Bat Biology and Ecology Studies #Ecology and biodiversity studies #Wildlife Ecology and Conservation
paper · pdf · doi:10.55957/wawk6114
openalex publication_date 2025/06/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
As part of a project-related functional check, data on the use of two bat crossing facilities ins- talled during the construction of the new K 7532 district road (northwest bypass Biberach, Baden-Württemberg) were collected and evaluated. These metal crossing aids (aka “bat bridges” or “bat gantries”), which are inexpensive compared to other types of construction, especially fully-qualified green bridges, were anchored at the end of 2012 and the road was opened to traffic in June 2013. Functional checks were carried out in 2014 and 2016. Unfortunately, it was not possible to realize a further planned investigation phase from 2020 onwards. In 10 survey nights with direct observation (5 each in 2014 and 2016), 78 road crossings of species with a high structural bond in flight (species of the genus Myotis sans the greater mouse-eared bat) and 241 road crossings of species with a medium structural bond (principally comprising species of the genus Pipistrellus, mainly P. pipistrellus) were observed at one of the crossing facilities and the associated reference site. In almost 80 % of cases, the crossing facility was flown through or otherwise used as a guiding structure by crossing individuals of the species with high structural bond (Myotis daubentonii, M. mystacinus, M. nattereri). This percentage was considerably lower for individuals of species with a medium structural bond. Although some of the animals also used the crossing facility (around 28 % of the recorded crossings), most of this group crossed the road at a greater height and largely independently of the crossing facility. Other individual aspects are also discussed. The present results cannot be used to justify generally low quality requirements for functionally important crossing facilities for bats, as the specific conditions of the present case must be taken into account. However, they do show that such a structure is used in particular by species with a high structural bond when flying over roads. In this respect, such crossing facilities can play a role in reducing the fragmentation effect of roads and traffic-related collision risks, in terms of planning and nature conservation. Such an approach is also of interest to, and appropriate for, other cases in which it is not necessary to work with crossing facilities with higher predictive reliability or those with better synergy effects for additional species groups. This must be assessed on a case-by-case basis.