Abstract
A bat census in the years 1981–2010 (repeated twice during each hibernation period in January and March) showed upward trends in many populations of bats hibernating in the Szachownica Cave (central Poland). Total numbers of the bat assemblage, which consisted of 11 species, increased within the study period from 178 to 1477 individuals in the first decade to 835–2902 in the past decade of the study, with the highest rates of increase noted in Barbastella barbastellus, Plecotus auritus and Myotis nattereri. Myotis myotis and Myotis daubentonii showed only slight upward trends. In the years 2009–2010, Myotis bechsteinii occurred in markedly higher numbers (up to 24 individuals) as compared to previous years.
©2011 by Walter de Gruyter Berlin New York
