Hibernation and Aestivation

Poikilotherms pass the winter in a resting state, known as hibernation. When they enter a resting state in response to heat or drought, the condition is called aestivation. In general Poikilotherms derive two types of benefit from the resting states that may enter during times of environmental stress.

First, by virtue of their special physiological state, the animals may enjoy an enhanced physiological ability to cope with the extreme conditions. (Example increased freezing resistance etc.) Second, they are often permitted to remain continuously in favourable microhabitats. Their metabolism is depressed to such an extent that the store of nutrients (example, body fat) can augment. The variety of mechanisms exploited by Poikilotherms in escaping some of the rigors of extreme temperatures may be divided into behavioural and physiological adaptations.