Wintering of an urban bat (Pipistrellus kuhlii lepidus) in recently occupied areas

Urbanization is one of the main drivers of ecological change in the modern world. In most cases, species diversity in urban landscapes is lower than in natural ones; however, some groups of animals are able to exploit and benefit from urban habitat. Pipistrellus kuhlii s.l. is (P. k. lepidus according to recent taxonomic review), a common European urban bat, whose range has expanded on a wide scale in the last 40 years. Thought to originate in Central Asia, this species has extended its range throughout Eastern and Central and Europe (a distance of more than 2,500 km2) in part by using human settlements as a habitat. This study examines the ecological features of P. k. lepidus in wintertime in the Eastern part of Ukraine, where this species has been living for 20 years. Thirty-nine winter records of P. k. lepidus(1,301 individuals totally) were selected from the database of the Bat Rehabilitation Center of Feldman Ecopark, 19 of which were groups from 2 to 641 individuals. Pipistrellus k. lepidus was found in various types of structures, but most often in administrative buildings (school buildings - 69%). Records were usually obtained during renovation works (85%), and the roosting sites were cavities between the wooden planks of window frames and a wall (75%). The records were obtained in 26 settlements, from a village (0,293 kmand 252 people) to the biggest cities in the country (Kharkiv and Odessa). The sex ratio in winter aggregation in adults varied from 47% to 61% of females and for this-year individuals from 48% to 58%, respectively. The body mass at the end of the hibernation period (February/March) decreases for 17–20% compared to the beginning of the period (December). Adult females have bigger body size (body mass and forearm length) (p-value < 0.05). Our results showed that P. k. lepidus is capable of forming homogeneous, sedentary populations in all types of settlements in Ukraine for these twenty years. However, this choice of habitat means that the species faces a high mortality risk from humans during building renovation and insulation works or pest control actions.