Nest-building in primates

Strepsirrhines may be nocturnal, diurnal, or crepuscular. Some may either occupy holes in trees or build nests. In lemurs s, build nests. Among lemurs, females of smaller species, such as the mouse lemur and giant mouse lemur, build leaf nests before birth for the protection of their young. Leaf nests in golden-brown mouse lemurs may provide thermoregulation benefits. Male mouse lemurs have been found sharing nests with up to seven females at a time during the mating season. In larger lemur species such as the Verreaux's sifaka, ring-tailed lemur and common brown lemur, the young cling to the mother and nests are not built. Aye-ayes build and use many nests—during one study, 8 aye-ayes were recorded to build and use as many as a hundred different nests over a period of 2 years. In lorisoids Lesser bushbaby mothers initially shelter their offspring, usually twins, in a nest or tree hollow, later concealing the infants in foliage while they forage at night. In some species, such as dwarf galagos, the day-sleeping nests may be shared by groups of females or occasionally by visiting males. == In hominid apes ==

Hominid apes construct nests during the day or by night, primarily for resting. The nests are not built using instinct but through behavioural patterns which are learned by the young from their parents or clan. Nest building is habitual behaviour, and nest-counts and faecal analysis at each nest site can be used to estimate hominid ape population counts and composition. In the case of orangutans and chimpanzees, social influences are probably essential for the animals to develop successful nesting-behaviour. Which in turn led to shorter and deeper sleep. In gorillas night nest Gorillas construct nests for day and night use. Day nests tend to be simple aggregations of branches and leaves on the ground, while night nests are more elaborate constructions usually on the ground but sometimes on trees, especially those of juveniles and females in areas submitted to a high poaching pressure. The nests may be wide in diameter and are constructed by individuals. Young animals nest with their mother but do not construct nests until three years of age, initially in close proximity to their mother. Gorilla nests are distributed randomly and the tree species used appears to be opportunistic. In orangutans nest Orangutans build day and night nests. Young orangutans learn by observing their mothers' nest-building behaviour. Nest-building is a leading reason for young orangutans to leave their mother for the first time. Starting at 6 months of age, orangutans practice nest building and gain proficiency by the time they are 3 years old. According to a non-verified hypothesis, archaic humans may have lived in tree houses until about 40,000 years ago. == Evolution ==

A study on the phylogeny of primate behaviour has revealed that the use of tree holes or nests are important in the life-history strategies of many strepsirrhine species and some New World monkey species. Alternative strategies of infant care that involve carrying infants rather than leaving them have evolved several times but have reproductive costs and generally slower rates of population increase compared to nest building. Use of nests for leaving young is thought to have evolved from nocturnal primates with solitary habits which possibly led to the evolution of nesting and parking behaviour in strepsirrhines such as galagoes. Galagoes give birth to a single young which is left in a nest as an infant and carried to a parking place in the vegetation orally by the mothers. In addition, the use of nests or tree holes as shelters for young infants differs functionally from the use of resting places by adult animals (which may be accompanied by infants). == See also ==