EN
The adaptation of animals to certain environmental changes increases their chances of survival. The animals which have undergone adaptation are able to synchronize their vital processes with the cyclic changes of the environment in which they exist. This process leads to establishing a certain biological balance, constantly controlled by endogenic factors. Due to the considerable drop in temperature, deficiency or lack of food, or shortening of the photoperiod, heterothermic animals, including hibernators, cease physical activities and allow for the lowering of their body temperature, thus saving large amounts of energy. This state of winter lethargy, connected with the fall of the body temperature and metabolism is called hibernation.