Gorillas: The use of the arms
The Africanapes, in great contrast to their Asian relations, are much more terrestrial in their habits. Gorillas live in central Africa, one form in the forests of the Congo basin, another slightly larger one in the cool sodden moss-forests that cover the flanks of volcanoes on the borders of Rwanda and Zaire. Young gorillas often climb trees, but they do so rather carefully without the confidence of Orang Utans. This is not surprising since the gorilla foot cannot grasp in the way that an Orang Utan's can, so the arms have to provide the main means of hauling up the body. When gorillas descend, they do so feet-first, lowering themselves with their arms, sometimes sliding down, braking by pressing the soles of their feet flat on the trunk and showering moss, creepers and bark all around them.