Thermal physiology of selected African ungulates with emphasis on the physical properties of the pelage

The ungulates include some of the largest land animals and, in consequence, they cannot avoid climatic stress as do small mammals. A great deal of information concerning the physiology of thermoregulation in domestic ungulates is available but relatively little is known about thermoregulation in wild ungulate species. Moreover, in the past, thermoregulation studies were conducted mainly in climatic chambers and consequently the effects of certain important environmental parameters were ignored. The pelages of mammals provide a barrier between the animal and its environment, and the physical characteristics of the pelage can feature prominently in the thermal adaptations of animals to specific climatic zones. Scholander et at. (1950), for example, have demonstrated the value of a thick pelage in arctic mammals. The thick pelage provides good protection against heat loss and thus extends the ambient temperature limits which the animal can tolerate without the need to increase metabolic heat production. Schmidt-Nielsen (1959) has shown that a thick pelage can also be advantageous to an animal in a desert environment. The thick, dorsal fur in the camel provides protection against excessive heat gain from the environment and thereby assists with water conservation. The colour of a mammal's pelage is also involved in the thermal adaptations to specific environmental conditions