Wintering range of Pipistrellus nathusii (Chiroptera) in Central Europe: has the species extended to the north-east using urban heat islands?

Recent climate warming is thought to affect the migratory behavior and geographical range shifts of Pipistrellus nathusii. This bat of the European temperate woodland zone is known to migrate up to 1900 km between its breeding and wintering areas where it uses overground roosts for hibernation. New wintering areas of the species have been recorded lately mainly in the cities of Central Europe, largely extending its winter distribution to the north-east. The growing detection of the winter occurrence of P. nathusii has coincided with an increase in mean winter temperatures and urban warming. Our analysis shows that a winter isotherm of -25 degrees C acts as a border for the winter occurrence of P. nathusii, and the species uses urban areas, most likely benefiting from the effect of urban heat islands. Accordingly, the island-like pattern of P. nathusii's regular wintering habitats distribution in Central Europe seems to reflect the thermal and structural diversity of the environment. The use of diverse anthropogenic roosts suggests that the species is well-adapted to urban habitats, thus demonstrating its ecological plasticity.