Oak woodlands and urban green spaces: Landscape management for a forest-affiliated bat, the Leisler's bat (Nyctalus leisleri).

Abstract

European forests have been intensively managed for a long time, threatening many forest-bound wildlife species, such as the Leisler's bat (Nyctalus leisleri). This rare species has been observed in deciduous forests, but we lack conclusive landscape-scale management recommendations for continental Europe. We therefore tracked the movements of 32 adult Leisler's bats from three local colonies with miniaturised Global Positioning System (GPS) loggers in two consecutive summers in a landscape that consists of a mosaic of woodland, forest plantations and farmland in Germany and in which wind energy production is expanding. We then analysed the habitat preferences of bats and how they interact with local wind turbines using an integrated step selection function in which we differentiated between roosting, commuting and foraging. Most spatial positions of Leisler's bats overlapped with the rotor-swept zone of local wind turbines, indicating that this species may be vulnerable at turbines. Further, Leisler's bats preferred oak woodlands and urban spaces, but avoided coniferous forests. For roosting, Leisler's bats preferred urban areas, probably because old trees were available along lanes or in churchyards. We call for careful landscape-scale management of oak woodlands and urban green spaces, particularly the preservation of old trees to support populations of Leisler's bats and other forest-affiliated bats. Furthermore, wind turbines should be sited well away from Leisler's bat colonies, as the flight altitude of Leisler's bats overlaps with the operating range of wind turbines, putting them at risk of being attracted to wind turbines during foraging trips.