Comparative aspects of the thermal biology of the short-tailed gerbil, Desmodillus auricularis, and the bushveld gerbil, Tatera leucogaster

Abstract

1. 1. The response of oxygen consumption (VO 2), thermal conductance ( C d and C min, body temperature ( T b), and evaporative water loss (EWL) of Tatera leucogaster and Desmodillus auricularis were measured over the range of ambient temperatures ( T a) from 5–35°C. 2. 2. Basal metabolic rate (BMR) of T. leucogaster was 0.841 ± 0.049 ml O 2 g −1 h −1 and lower than predicted, while that of D. auricularis was similar to the expected value (1.220 ± 0.058 ml O 2 g −1 h −1). D. auricularis had a high, narrow thermoneutral zone (TNZ) typical of nocturnal, xerophilic, burrowing rodents. 3. 3. D. auricularis and T. leucogaster regulated T b over the range T a = 5–35°C and kept EWL and dry thermal conductance at a minimum below the TNZ. However, the EWL of T. leucogaster increased rapidly above T a = 30°C. 4. 4. After comparison with data from other species, it was concluded that there is an optimum size for xeric, nocturnal, burrowing rodents.