The Chimpanzee is confined to the West African Sub-region, as defined by Dr. Bowdler Sharpe. It is known from Loango, along the banks of the Upper Congo, and Mr. Monteiro (P. Z. S., 1871, p. 544) says it is quite unknown to the south of the Congo; it also occurs throughout the country of the Manyema, in Central Africa, where Livingstone describes it under the name of Soko; and southward as far as 10° south latitude, to Lake Moero. Schweinfurth has recorded it from the Niam-niam country.
The Chimpanzees inhabit forest regions, and feed on wild fruits in the woods, and the products of cultivated gardens, not rejecting, when they can capture it, animal food. They live in separate families, or in limited communities of small families mixed together, but each male lives with his own single female. They are more arboreal than the Gorilla, but much less so than the Orangs. In many districts they seem to live on the ground.
They emit loud cries, shrieks, and howls in the morning and evening, and often during the night. "Since they are really accomplished in the art of bringing forth these unpleasant sounds, which may be heard at a great distance, and are reproduced by the echoes, it is impossible to estimate the number of those who take part in the dreary noise, but often we seemed to hear more than a hundred." (Pechuel-Lösche.) These Apes also build resting-places, not far from the ground, like the Orangs, composed of twigs and sticks on the branch of a tree or a crotch, in which the female and her young take refuge for the night, the male placing himself on guard beneath.
They seldom make an unprovoked attack on the natives wandering in the forest; on the contrary, they are peaceably disposed animals, glad to get out of the way of danger or possible enemies. Yet, when pressed, they form no mean antagonist. Biting is their principal mode of defence.
"As seen here," says Savage, "they cannot be called gregarious, seldom more than five or ten at most being found together. It has been said on good authority, that they occasionally assemble in large numbers in gambols. My informant asserts that he saw once not less than fifty so engaged, hooting, screaming, and drumming with sticks upon old logs, which is done in the latter case with equal facility by the four extremities.... When at rest, the sitting posture is that generally assumed. They are sometimes seen standing or walking, but when thus detected, they immediately take to all fours, and flee from the presence of the observer. Such is their organisation that they cannot stand erect, but lean forward. Hence they are seen, when standing, with the hands clasped over the occiput, or the lumbar region, which would seem necessary for balance or ease of posture."
Most of the accounts of the habits we have of Chimpanzees, refer to those of young individuals kept in captivity. There is still much to be discovered as to the ways and modes of life of the adults of both the Chimpanzee and the Gorilla. They are both very delicate, and in temperate climates rarely live more than a few months; a Bald Chimpanzee (A. calvus), however, survived five years in the Zoological Gardens, in London.
I. THE COMMON CHIMPANZEE. ANTHROPOPITHECUS TROGLODYTES.
Homo sylvestris (Ourang-outang), Tyson & Cowper, Phil. Trans., xxi., p. 338 (1699); Tulpius, Observ. Anat., p. 270, pl. 14 (1641).
Homo troglodytes, Linn., Syst. Nat., i., p. 32 (1766; pt.).
Simia troglodytes, Gm., Syst. Nat., p. 26 (1788); Blumenb., Handb., x., p. 73 (1803); Owen, Tr. Z. S. I., p. 344, pls. 48, 50-52, 55, 56 (1835); ii., p. 169 (1841); Schl., Mus. Pays-Bas, vii., p. 8 (1876).