Thermoregulation and energy metabolism in the lesser bushbaby, Galago senegalensis moholi

Abstract

Thermoregulation and energy metabolism were studied in adult and juvenile G. s. moholi at ambient temperatures ranging from 6 to 35°C. In the adults, oxygen consumption decreased with increasing ambient temperature reaching minimum values of 0,7 ± 0,04 (males) and 0,9 ± 0,04 ml O₂ g⁻¹ h⁻¹ (females) at the lower critical temperature of 28°C. Between 28 and 35°C, the thermal neutral zone, oxygen consumption remained constant and was found to be 32% (males) and 16% (females) below the theoretical mass specific level. In the juveniles oxygen consumption also decreased with increasing temperature but reached the lowest measured value at 35°C. Oxygen consumption in this group was significantly higher than in the adults at each temperature. Body temperature remained constant over most of the temperature range, but increased significantly in the female and juvenile groups at 35°C. Evaporative water loss increased linearly with temperature in all groups. At 35°C less than 50% of the endogenous heat production was dissipated by this means. The results are discussed with reference to the age, habitat and behaviour of the animal.