Hibernation, Daily Torpor and Estivation in Mammals and Birds: Behavioral Aspects

Abstract

Torpor is the most effective means of energy conservation available to mammals and birds. Torpor is often viewed as a state of utter inactivity devoid of any behavioral aspects. However, recent work has shown that even torpid individuals do express behaviors. Torpid mammals can move at low body temperatures from a torpor site into the sun to passively rewarm and minimize energy expenditure. Social torpor involves coordinated interaction among individuals, and some species even eat or mate while torpid. Behaviors expressed before the torpor season include selection of suitable hibernacula and storage or hoarding of appropriate and sufficient amounts of fuel.