Localization of hibernation sites and winter activity of Nyctalus noctula (Chiroptera) in urban environment (Lviv)

Abstract

Winter activity of N. noctula in the urban environment was investigated in the city of Lviv (Ukraine). The studies were performed using an ultrasonic detector and visual observations. Totally 27 wintering shelters were found, mostly located in narrow gaps between block houses (50%), as well as behind decor slabs (4.1%), in wall cavities (4.1%), on balconies (12.5%). No preferences were found in the altitudinal choice of shelter location and the house walls of a particular exhibition were not found/ A positive correlation between the intensity of relative flight activity of bats and the average daily temperature was revealed. No flight of bats was recorded below –4°C, although vocal activity in shelters was recorded at outdoor temperatures of about –15°C. It is assumed that the choice of shelters depends mainly on the general availability of shelter and their microclimatic characteristics. There is a tendency to further shift the wintering zone of N. noctula in the northern direction and increase the scale of its wintering in the urban landscape.