Successful Wintering of the Noctule Nyctalus noctula on a Balcony in Warsaw (Central Poland)

Wintering of the noctule Nyctalus noctula was recorded on a balcony in Warsaw (central Poland) in winter 2018/2019. About 40 individuals of this species inhabited a shopping bag closed on top. At the end of February and the beginning of March 2019 bats ended hibernation and flew out of this provisional roost. Three dead individuals remained there. Recent climate change resulting in milder winters makes noctules able to overwinter in central Poland even in shelters poorly isolated from external conditions.