Northward expansion of the winter range of Nyctalus noctula (Chiroptera: Vespertilionidae) in Eastern Europe.

Before 1990, mass wintering of the noctule bat ( Nyctalus noctula) in Ukraine was known from the Ukrainian Transcarpathia and the south of the country. For the rest of Ukraine, as for other regions of Europe to the north and the northeast, the species was considered a migratory one. Today, the noctule bat is known in winter for 23 (of 25) administrative provinces of Ukraine, and winter colonies have been recorded in most of them. In Ukraine, N. noctula is a seasonal epilithic species, which hibernates mostly in multi-storey buildings serving as cliff-like structures. The retrospective analysis of bat data from Ukraine and adjacent countries shows that new records refer to the expansion of the species' winter range, which occurred during the last decades. The border of the winter range of N. noctula in Eastern Europe now lies at least 500-600 km northward than previously assumed. The analysis of the air temperature datasets demonstrates that warming of winters cannot be the only factor determining this process. Mass appearance of high buildings and roosts associated with them is thought to be an important condition driving the expansion. [ABSTRACT FROM AUTHOR]