The length of awakening time from hibernation of three species of bats

The time of awakening from winter sleep has been studied in three species of bats: Rhinolophus hipposideros, Myotis myotis and Plecotus auritus under natural conditions. Seasonal changes in the time of awakening have been found in bats R. hipposideros wintering in constant thermal conditions. In autumn (October) and in spring (April) the time was shorter than that observed in the middle of the winter sleep (January).