This is a state of metabolic depression and inactivity in endothermic (warm blooded) creatures. It is displayed as a reduced heartbeat (by up to 95%), low metabolic rate, slow breathing, and low body temperature. Critters that hibernate typically prepare for it by building up an abundance of body fat during late summer and autumn that helps provide them with energy throughout the winter months. There are 2 types of hibernation: facultative & obligate hibernation. Facultatives hibernate when it’s too cold and food supply has been reduced. Obligates are able to sleep despite access to food and comfortable temperatures. A facultative hibernator would be the black-tailed prairie dog. A few obligate hibernators are: ground squirrels, mouse lemurs, and butterflies.
