Hibernation the summer months is aestivation. Often associated with low temperatures, the function of hibernation is to conserve energy when sufficient food is unavailable. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months depending on the species, ambient temperature, time of year, and the individual's body condition. Before entering hibernation, animals need to store enough energy to last through the duration of their dormant period, possibly as long as the entire winter. Larger species become hyperphagic, eating a large amount of food and storing the energy
Lemur the dry winter season, when food and water are scarce, and can exhibit daily and prolonged torpor during the dry season. Daily torpor constitutes less than 24 hours of dormancy, whereas prolonged torpor averages two weeks in duration and signals hibernation. Mouse lemurs have been observed experiencing torpor that lasts for several consecutive days, but dwarf lemurs are known to hibernate for six to eight months every year, particularly on the west coast of Madagascar. Dwarf lemurs are the only primates known to hibernate for extended periods. Unlike other hibernating mammals from temperate regions, which have to awaken regularly for