Thermoregulation in Bats Exposed to Low Ambient Temperatureis

Abstract

Heart rates and rectal temperatures (Tr) were recorded from inactive bats exposed to stepwise changes in ambient temperature (Tn) in the range between —5°C and 10°C. An increase in heart rate and in the difference (ΔT) between rectal and ambient temperature (ΔT — Tr — Tu) with decreasing ambient temperature below 5°C was found. The bats remained in the dormant state but were able to arouse from dormancy in response to mechanical stimuli. The results indicate that the species of bats studied possess thermoregulatory ability during dormancy and that this ability is a homeostatic mechanism and thus different from the process of arousal.