HEAT PRODUCTION IN THE LEVANT VOLE MICROTUS GUENTHERI

ABSTRACT

The Levant vole Microtus guentheri is a common species in the “Fertile Crescent". The populations of this species in Israel are marginal and they seem to be well adapted to the long dry and warm season of the Mediterranean ecosystem. Heat production and dissipation, nonshivering thermogenesis, and food and energy consumption were studied in voles acclimated to an ambient temperature of 25 °C under a photoperiod regime of 12L:12D. The Levant role has a high metabolic rate. Its resting metabolic rate is 39% higher than predicted from body mass. The high metabolic rate is sustained by high food and energy intakes, as well as by a high thermal conductance. High thermal conductance may be considered as an adaptation for dissipating heat in a warm environment. Nonshiveiing thermogenesis is relatively low and therefore it may be assumed that, under these conditions, the Levant vole does not depend on it as a major source of heat production.