Great Apes and Humans: Hominidae

African apes are mostly ground-dwellers, walking on their knuckles and feet. The lighter species climb trees, swinging by their arms from branch to branch in a mode of traveling called brachiation (brake-ee-AY-shun). Orangutans are arboreal (tree-dwelling). On the rare occasions that they descend to the ground, they walk on their clenched fists. All great apes are diurnal, foraging during the day and sleeping in nests at night. Some take long breaks for grooming sessions.

Great apes are not seasonal breeders. Females have single births, caring for the young for a lengthy period with no help from the fathers. Male gorillas and chimpanzees engage in rivalries and takeovers that result in infanticide (killing of the young). Bonobo females are constantly receptive to mating. Orangutan males may commit forceful mating.