Summary:

Wildlife crossings are resource-demanding structures constructed to minimalize impacts of human-made barriers (e.g. road and railway corridors) on the natural environment. Therefore monitoring of functionality of these engineering constructions is vital. The aim of monitoring is to control if implemented technical and biological solutions have been accepted by the wildlife. The paper concerns functionality analysis of wildlife overpass crossings constructed in the area of S3 expressway junction with A3 motorway. The research method was direct observation bats flight activity through gateway area at reference sections. It shows that constructed section of S3 motorway disturbed natural bat migration routes. The flights of bats at collision elevation 4 m over road level are 20% of total flight frequency occurring outside gateway sections. Efficiency of bat flight guiding on wildlife crossings depends on many factors e.g. biometric parameters of trees, road surface level declination in comparison with surrounding terrain level at the crossing area, location of clearings in the vicinity of crossings.
The wildlife crossing analyzed in the paper is accepted by bats, however its functionality should be improved both by implementing technical modifications - increasing width of gates, decreasing of road surface level in comparison with terrain level and by implementing biotic modifications - properly introduced tree compositions and ecotone zones of tree stands.