Hibernation is a state of energy conservation during which body temperature and metabolism are drastically reduced. If this state lasts longer than 24 hours, it is called hibernation. Shorter periods are called daily torpor. There are many mammals that hibernate. However, among primates hibernation is a rare capability, as it had been previously found in three species of lemurs only. Lemurs exclusively live on the island of Madagascar, where they hibernate during the dry season, mainly to conserve water. Now a team at the Research Institute of Wildlife Ecology at the Vetmeduni Vienna, collaborating with colleagues from the Vietnamese Endangered Primate Rescue Center, has discovered another primate that hibernates: the pygmy slow loris (Nycticebus pygmaeus). They belong to the so-called wet nosed primates, reach a body size of about 20 centimeter and a body mass of 400 gram. They live in Southeast Asia and are nocturnal, tree-living animals.
“Our new finding of a hibernating primate species outside Madagascar sheds new light on the evolution of hibernation,” emphasizes Ruf. “Possibly, hibernation as an overwintering strategy was lost in other primates in Africa, Asia, and the Americas. However, perhaps hibernation is also used by further primate species, which have not been studied yet.”