Clearing cold, snow masses and long winter nights: feathered animals move to the south, other four-legged friends get cold feet, turn their backs on the world and retire for weeks in their building. Engraved and well fed, they simply oversleep the uncomfortable season. But hibernation is not the same as hibernation. Mammals in the wild belong, like birds, to the so-called equally warm (homeothermic) animals and hibernate or hibernate to survive the cold season. Pets - except turtles - are not among the winter sleepers. They remain active and get a thick winter coat as frost protection.
Marmots, dormice, dormice, hamsters, hedgehogs, shrews or bats actually go into hibernation: they drastically lower their body temperature, sometimes down to zero degrees, bats even lower. The lowered metabolism is kept stable in hibernation by oxidation of fat.
Like the metabolism, the blood sugar content and blood pressure are lowered, breathing, heartbeat and blood circulation are slowed down. The urination is set depending on the species almost or completely. Only small animals up to eight kilograms of body weight can slumber with such impunity in the winter.
Larger animals, such as badger, washing and brown bear, but also the squirrel, hibernate, because a strong lowering of body temperature would be lethal for them: they reduce their activity in the cold season to a minimum, to save energy. Winter rangers only lower their body temperature by a few degrees in winter, often waking up and eating.
The so-called cold starre exists only in animals with a change in temperature such as fish, amphibians, reptiles and insects. Warm-blooded animals do not keep their body temperature constant, but change it with the ambient temperature. If it is too cold frog, lizard or bumblebee, they lapse into a rigidity called cold star. In contrast to equally warm winter sleepers, cold-frozen animals can not be awakened by external stimuli.
Incidentally, there are winter hollers, winter hibernates and cold stares as well as summer sleepers, mainly in the tropics and subtropics, for example, the Mausopossum, the yellow ground squirrel and the cactus mouse.