Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and/or lower metabolic rate. Hibernating animals conserve energy, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate. Although often associated with cold temperatures, the root purpose of hibernation is to conserve food during a period when sufficient food is scarce. It is the animal's slowed metabolic rate which leads to a reduction in body temperature and not the other way around. Hibernation may last several days, weeks, or months depending on the species, ambient temperature, time of year, individual animal's body condition, and fur on the animal's body.
Hibernation during summer months is known as aestivation. Some reptile species are said to brumate, or undergo brumation, but the connection to this phenomenon with hibernation is not clear. Before entering hibernation, most species eat a large amount of food and store energy in fat deposits to survive the winter. Some species of mammals hibernate while gestating young, which are either born while the mother hibernates or shortly afterwards.
There is a long list of hibernating animals that includes mammals, amphibians, fish, reptiles, insects, birds, etc. Bees, earthworms, snails, mud turtles, butterflies and moths, gila monster, wasps, rodents all undergo hibernation. When you have a look at the list, you will find a variety of species who follow this survival strategy. Mammals such as bats, bears, ground squirrels, undergo hibernation. Reptiles like tortoises, snakes, too undergo sleep state. Birds like Poor-Wills, swifts and nighthawks, as well as amphibians like toads and frogs too hibernate.
These animals store food as body fat during the months of summer and fall. When they hibernate they use up their body fat for the little energy that they need to live during hibernation. Some animals like squirrels store their food in burrows and caves. This food works as a light snack when they do wake up from their sleep for a break. In case of cold-blooded animals, their body temperatures drop with the drop in environmental temperatures. This means their body temperatures will match the environmental temperatures. When the temperatures outside begin to change, and the air becomes warmer, these animals will wake up from their deep sleep.
Frogs and Toads