Why do elephants flap their ears?
The blood flow in the ear of the African elephant Loxodonta africana was measured In anaesthetized animals using the dye dilution technique at the same time as the arterio-venous temperature difference. The calculated heat loss from the ear is shown to be a substantial proportion of the total metabolic heat-loss requirement calculated from body surface area estimations. Reasons are advanced for believing that ear blood flow is controlled in the interests of thermoregulation. Behavioural fanning activity and the large ear surface area and surface to volume ratio suggest that this organ is of major importance in thermoregulation under warm environmental conditions.