Ecology of bats hibernating underground in central Poland

Abstract

With 6 Tables & 3 Figs.] Bats hibernating in underground parts of a fortress in central Poland were studied over three seasons: 1979/80, 1980/81, and 1981/82. A total of 1072 individuals were marked, representing nine species. The most abundant were Barbastella barbastellus (48.2%) and Myotis daubentoni (35.3%). It has been found that the coolest and most exposed places were occupied by B. barbastellus and P. austriacus, contrary to bats of the genus Myotis. "Autumn" bats were distinguished, M. myotis and M. daubentoni, most abundant in October, and "winter" species occupying the fortress from late October or early November -B. barbastellus, M. nattereri, and P. auritus. There was a continuous exchange of individuals over the hibernation period, and the proportion of individuals noted more than once did not exceed 40%. In populations of E. serotinus and B. barbastellus males outnumbered females. The sex ratio in M. daubentoni and B. barbastellus varied over the hibernation period. The duration of hibernation, as estimated from changes in body weight, was 175-190 days for M. daubentoni and 140 days for B. barbastellus.