Temperature regulation in endotherms

Abstract

This chapter studies temperature regulation in endotherms. Endotherms compensate for heat loss to their environment in order to maintain their body temperature several degrees above ambient. Animals decrease their thermal conductance to minimize their rate of heat loss. This can be achieved by erecting hairs or feathers to increase the insulating layer of air, or by the operation of countercurrent heat exchangers in the extremities. The thermoneutral zone is the ambient temperature range within which an animal does not need to change its rate of heat production to regulate its temperature. The chapter then looks at how endotherms regulate their body temperature in hot conditions, cold conditions, through the seasons, and in water. Some species of endotherms exhibit regional endothermy: they generate heat and retain it in specific regions of the body. The chapter considers endothermic fishes, reptiles, and insects.