Importance of anthropogenic winter roosts for endangered hibernating bats

Abstract. We aimed to assess the importance of anthropogenic roosts for bats hibernating in the Roztocze National Park (south-east Poland), based on data collected from 2009 to 2021. We recorded 310 bats from nine species hibernating in 27 artificial underground roosts (root cellars and basements of buildings). The most abundant and constantly recorded species were Plecotus auritus (60.2%), Barbastella barbastellus (20.6%) and Myotis nattereri (14.2%), while the remaining species can be considered of secondary importance; Plecotus austriacus (1.3%), Myotis myotis (1.9%), Myotis bechsteinii (1.3%), M. daubentonii (0.3%), Myotis mystacinus sensu lato (0.3%) and Eptesicus serotinus (1.3%). An estimate of the Shannon diversity index gave a mean H = 0.947 (SD = 0.247, range 0.377-1.352), while the Buzas and Gibson´s evenness index gave values of E = 0.695 (SD = 0.125, range 0.551-0.940). The Shannon index was positively correlated with the number of recorded bats and varied substantially among years.