Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus—I. Metabolic rate and body temperature

Abstract

1. 1. Oxygen consumption and body temperature were measured at ambient temperatures between 18 and 38°C. 2. 2. Metabolism, body temperature and thermal conductance are significantly lower in the semiarid population than in the montane population. 3. 3. Thermalneutral metabolism (at 30°C) is 13 and 23 per cent lower than predicted by body weight in the montane and semiarid populations, respectively. Thermal conductance below thermal neutrality is equal to predicted values in the montane population and 10 per cent lower than predicted in the semiarid population. 4. 4. Differences between populations are greatest at high ambient temperature and are discussed relative to diurnal activity and habitat.