Seasonal Changes of Thermoregulation in the Mole Vole <i>Ellobius talpinus</i>

Abstract

Seasonal changes of thermoregulation were studied in mole voles (Ellobius talpinus Pall.) from southern Siberia. Spontaneous fluctuations of body temperature were significantly higher in summer than in autumn. Standard deviations from average daily temperature of individuals were 0.95 (N=212) in summer and 0.57 (N=248) in autumn. Thermoregulatory response to cold exposure and to norepinephrine injection varied in different seasons of the year. In cold seasons, mole voles are able to maintain temperature homeostasis in a wide range of environmental conditions. This ability declined only in summer. Hence, the mole vole's adaptation to the continental climate is based on distinct seasonal variations of thermoregulation. In summer, thermoregulatory mechanisms are similar to those of desert eusocial fossorial species, but in spring and autumn, mole voles share the thermoregulatory strategies of boreal terrestrial rodents.