The roost preference of Nyctalus noctula (Chiroptera, Vespertilionidae) in summer and the ecological background of their urbanization

Abstract

The paper summarises the investigation of roost-selection of Nyctalus noctula in prefabricated panel buildings and trees. The noctule bats occupy only special man-made constructions which are similar in many ways to the natural hollows, providing the same or better climatic conditions than in a treehollow. The bats prefer similar height and width of entrances both in the trees and in the panel buildings. In summer the noctule bats prefer roosts situated on the western walls of panel buildings. The rhythm of temperature fluctuation in that side best corresponds to the daily life cycle of the bats. Because of the good roosting possibilities, the density is higher in housing estates than in natural forests. The noctule bats occupy buildings with well determined characteristics. When talking about urbanization, we do not refer to adaptation but only to the use of roosts having more advantageous conditions.