They spend much time on the ground but still have dexterous feet. The are agile climbers and spend the night up in the trees in nests they create by bending together several branches. Chimps live in large groups and depend on individualized faces to recognized each other. The abiding relationship, at least five years, is between mother and child. Skills of motherhood are learned, not instinctive.
Friendships are important, and are reinforced by grooming.
Grooming also comforts the young, soothes tensions, and reinforces the social hierarchy. Their complex and stimulating social lives are important evidence of their close relationship to the last primate, humans. Name three fundamentally different primate communication systems. Give examples of specialists in each. Attenborough says that 15 million years ago the first move out of the trees and onto the savanna was made by our ancestors.