The Encyclopedia Americana (1920)/Chimpanzee
CHIMPANZEE, chĭm-păn′zē or chĭm-păn-zē′, an anthropoid ape (Anthropopithecus niger), native to the equatorial region of Africa, from the Atlantic Ocean to the Nile, within a belt about 20 degrees wide. In this extensive territory it exhibits much diversity and has many local names, but whether these indicate more than one species is still to be determined.
This ape would measure in an average specimen about 5½ feet tall, but the spread of its arms and hands would be nearly 6 feet, and the girth of the chest about 35 inches. Old males often exceed these measurements, but there is not such a disparity in size between the sexes as in the gorilla. The massive structure of the bones and muscles implies great strength, but it certainly is not so prodigious as that reputed of the bigger gorilla. The forearm and hand are longer than in the other anthropoid apes (q.v.) except the gibbons, in conformity with the more arboreal habits; the skull is brachycephalic, the ears are proportionately large and stand out from the head, and the nostrils are wide. The skin on the face is naked and yellowish, surrounded by long black hair that hangs over the head and shoulders and depends from the elbows. The body is covered with shorter hair, typically shining black, but brown on the back in some specimens, especially those taken along the Ituri River in the Kongo region. In disposition the chimpanzee is milder and more timid than the always ferocious gorilla, and in captivity it is far more tamable than that irreclaimable beast, which is more primitive in every way.
Chimpanzees are forest-dwellers, and are not easy to find and observe, and still less to catch. They go about in family parties, probably mated for life and frequently gather into bands of two or three families. During the day their time is spent mainly in some big tree, dozing, nibbling at young shoots and “loafing” quietly. In the early morning and again late in the afternoon they descend to the ground and grab for roots and tubers, or search for fruit and the leaves of certain succulent plants of which they are fond. An intelligent traveler-naturalist, Major Cuthbert Christy, writing recently of his observation of these apes in the Kongo forests, says that where a large troop has been feeding one might believe a herd of real pigs had been at work. Much food is also gathered in the tree-tops, including fruit, insects and birds' eggs. The appetite for fruits makes the chimpanzee a menace to the plantations, especially when bananas are in edible condition. The natives guard the plantations, and as the animal is timid toward man this usually saves the crop; but when he cannot run away, the chimpanzee at bay is a formidable foe, using his long, sinewy arms and sharp teeth with deadly effect. He is even said to be a match for the leopard. The stories of his capturing and carrying off negro women or children are not substantiated.
The presence of chimpanzees in a neighborhood is quickly known to the people, “for at intervals during the day, either singly or in chorus, they indulge in bouts of far-echoing, half-human, half-maniacal shouts and hoots, rising crescendo to what seems like fiendish laughter . . . till the forest rings with the sound.” Just at daybreak this forms a kind of concerted uproar that lasts for several minutes.
At night each adult climbs a tree, usually of small size, and by bending down branches and heaping leaves and twigs on them, constructs a platform big enough for a bed, on which he or she lies down and spends the night. These little platforms are believed to be used only once, and old ones are common sights in the forest; when the female is about to bring forth the one or sometimes two young, borne by her annually, she builds a similar platform-bed, and there the little ones are born and rest until able to travel or be carried away. The chimpanzees are so heavy that the big ones are clumsy in climbing about, as compared with smaller monkeys, and when in haste to make their escape from men, whom they will avoid and flee from whenever possible, they take to the ground. “At the first sign of danger,” says Major Christy, “the wary old male forsakes his family, comes down from the tree-top with a few acrobatic swings and a drop, and makes off along the ground, not exactly on all fours, though something like it, using his great arms to help himself along, . . . to push swinging branches and creepers out of the way rather than for running with. When on all fours his fingers are doubled on the palms of his hands so that he walks on his knuckles.” The arms are not so much needed or actually used for progression as has hitherto been believed.
Chimpanzees have been seen in menageries and zoological gardens in Europe since the middle of the 17th century; and many accounts have been given of their docility and submission to training, in which they exhibit an ability to learn to do things, and handle implements in a way that is most interesting and amusing. They also when young show much affection for kind trainers. They are very susceptible to diseases, especially of the lungs, and rarely survive long in captivity; and as they grow to adulthood they are likely to grow fretful, morose and even dangerous. Consult Hartmann, ‘Anthropoid Apes’ (New York 1886); Elliot, ‘A Review of Primates’ (New York 1912), and general works on natural history. See Ape; Gibbon; Gorilla; Orang-utan.