Body Temperature Dynamics of the Ciscaucasian Hamster (Mesocricetus raddei) (Cricetidae, Rodentia) during Hibernation

The body temperature dynamics of the Ciscaucasian hamster (Mesocricetus raddei) during winter hibernation was studied in semi-natural conditions (a mesh cage buried in the ground, where animals could dig burrows) in mountainous Dagestan. Thermologgers were implanted intraperitoneally into seven adult animals (three females and four males) to record the body temperature at 30 min intervals. All individuals successfully overwintered and exhibited regular episodes of hypothermia. The average of the total duration of one heterothermia period was 192 ± 6.8 days, and that of one hypothermia and normothermia episode was 155.3 ± 6.2 h and 16.5 ± 1.2 h, respectively. The minimum body temperature reached +0.5°C. It has been shown that the body temperature and the duration of hypothermia episodes are negatively correlated with the temperature inside the burrow. Adaptive hibernation mechanisms of the Ciscaucasian hamster and other hibernating mammalian species are discussed.