Seasonal Variations in the Endocrine System of Hibernators

Abstract

The term hibernation is often used in a loose sense to signify any state of torpor. However, it should be confined to horneotherms that, at certain times and under natural conditions, abandon homeothermia and permit body temperature to fall as low as the environmental temperature, with a low limit of about 0{\textdegree}C --- and are able to regain the homeothermia at any time regardless of environmental temperature. Thus defined, hibernation occurs in some species of bats, birch mouse, chipmunks, dormice, ground squirrels, hamsters, hedgehogs, marmots, pigmy possums and humming-birds, whereas bears and badgers are not true hibernators.