Sandbathing is thermoregulatory in the Mongolian gerbil, Meriones unguiculatus

Three experiments assessed the importance of behavioral regulation of hair lipids for thermoregulation in Meriones unguiculatus. Experiment I demonstrated that animals exposed for 8-11 days at 34 degrees C had reduced body-hair lipids and a smaller increase in body temperature when exposed to tungsten light radiation than animals exposed to 5 degrees C. Experiment II confirmed that the effect was due to differential hair lipids and not heat acclimation, as the hyperthermic response and change in hair lipids were attenuated when animals were allowed to sandbathe at 34 degrees C. Experiment III showed that animals tested periodically at 30 degrees C sandbathe more frequently than those tested at 5 degrees C. Body-heat regulation is associated with variations in hair lipids and associated changes in coat color and the ability to reflect or absorb radiant energy (Thiessen, Pendergrass, & Harriman (1982) Journal of Thermal Biology, 7, 51-66). Sandbathing is temperature dependent and apparently mediates thermoregulatory changes in heat absorption and reflectance.