Nest-building in primates

Certain extant strepsirrhines (lemurs and lorisoids) and hominid apes (humans, chimpanzees, gorillas and orangutans) build nests for both sleeping and raising families.

Nest-building by hominid apes is learned by infants watching the mother and others in the group, and is considered tool use rather than animal architecture.

[3] It has been speculated that a major evolutionary advance in the cognitive abilities of hominoids may first have occurred due to the development of nest-building behaviour and that the transition from nest-building to ground-sleeping led to "modifications in the quality and quantity of hominid sleep, which in turn may have enhanced waking survival skills through priming, promoted creativity and innovation, and aided the consolidation of procedural memories".

[8] Male mouse lemurs have been found sharing nests with up to seven females at a time during the mating season.

[9] In the Ruffed lemur (Varecia variegata), nests are made from locally collected material and may also be lined with hair plucked from their own body.

[5] Aye-ayes, being nocturnal, build oval-shaped nests from nearby branches and lianas for day time use.

[12] 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.

[9] In some species, such as dwarf galagos, the day-sleeping nests may be shared by groups of females or occasionally by visiting males.

[1] The nest building behavior is estimated to have originated during the Miocene, when the body of the ancestors of modern apes increased in size.

At some research sites such as Bili forest, in Congo, chimpanzees can build a significant proportion of their night nests on the ground.

Starting at 6 months of age, orangutans practice nest building and gain proficiency by the time they are 3 years old.

[1] Orangutans make "pillows" by clumping together leafy branches with the leaves in the center and the twig shoots pointed outward.

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.