Animals

Colonial, formerly found in groups of about 100 individuals. Earlier reports of monogamy probably erroneous. Relatively long gestation period (111 days) but still may produce two litters during the long summer season. Gives birth to two or three exceedingly precocial young weighing about 35 g. each. Lactation lasts between six and eight weeks. Both males and females become fertile at about eight months of age. Life span is 10 years in the wild, twice that in captivity.
Nocturnal (large eyes and long vibrissae). Dense fur indicates the depth of cold at the altitudes they inhabit. This fur has led to their extirpation. Feet adept at jumping, clinging and climbing over rocks.
As late as 1900 an estimated 500,000 skins were being exported annually from Chile. Shortly thereafter, however, chinchillas became rare and the skin price went higher. It is the most valuable fur of any in the world, considering its size and weight. Wild chinchilla coats have sold for $100,000, and that was years ago. Their descendants are bred commercially throughout the world. Reintroduction attempts have not been successful.

Bibliography
Nowak, Ronald and John Paradiso. 1983. Walker's Mammals of the World

Silvery gray pelt, each hair tipped by black, very dense and soft, with up to 60 hairs growing from each follicle. Adults weigh about 500-800 grams with females larger than males. Large, rounded ears and eyes, pupils vertical slits. The short forefoot and narrow hind foot have four digits with stiff bristles surrounding the weak claws. Tails have coarse long gray and black hairs on the dorsal surface. Vibrissae are very long (110 mm).
Geographical range:
Relatively barren foothills of the Andes at elevations of 3,000 to 5,000 meters and in the coastal mountains of Chile, sheltering in crevices and holes among the rocks.
Strictly herbivorous, eating any available vegetation.

Chimp communities are made up of 15 to 120 animals. These communities lack a definite leader and are usually split into a number of subgroups which are temporary and change in composition within a matter of hours or days ("fusion-fission" groups). Mothers often travel alone with only their offspring. Males seldom or never leave the community into which they were born, whereas most females migrate to a new community during an adolescent estrus period. In male relationships, tension is routinely expressed in dominance interactions when parties meet, but males also spend much time grooming each other. They form a loose dominance hierarchy.
For sleeping at night, each chimp (except infants who nest with their mothers) constructs a nest of vegetation 9-12 meters high in a tree. Males may hunt cooperatively for baby monkeys or bush pigs and even "share" some of the meat. Goodall has documented serious territorial fights.

Bibliography:
De Waal, Frans. 1982. Chimpanzee Politics: Power and Sex Among Apes

Females in heat have prominent swelling of the pink perineal skin, lasting two to three weeks or more, and occurring every four to six weeks. Males have relatively huge testes. Puberty in both sexes occurs at about seven years, but males are not fully integrated into the social hierarchy until 15 or so. Females raised in captivity begin mating at eight to nine years and give birth for the first time at 10-11 years old. Wild females mature three to four years later. There is no breeding season. Chimpanzee females are not receptive for three to four years after giving birth, then resume sexual activities for one to six months until conception.
Females mate only when in heat. For the first week or more, female chimps are promiscuous and mate on an average of six times a day. Toward the last week of estrus, when ovulation occurs, high ranking males may compete for mating rights. Occasionally, an exclusive "consortship" is formed, a female and male eluding other members of the community for days or weeks. Reproductive capability in the female may last at least until the age of 40. Maximum life span in the wild may be 60 years.
The newborn is helpless with only a weak grasping reflex and needs support from the mother's hand during travel. Within a few days it clings to the mother's ventral surface without assistance, and begins riding "jockey-style" at 5-7 months. By four years, the infant travels mostly by walking, but stays with its mother until at least five to seven years old. Weaning begins in the third year.

Feed on a wide variety of foodstuffs (over 80 different items have been catalogued) with the largest proportion consisting of fruit and young leaves. In long dry seasons, buds and blossoms, soft pitch, stems, galls, honey, bark and resin, seeds and nuts are also eaten. Animal prey makes up as much as five percent of the diet, with social insects, such as ants and termites, providing the largest amounts. On rare occasions small game (monkeys, pigs, and antelope) is hunted. Feeding is essentially an individual activity, but after a cooperative hunt may share morsels in response to begging by others. There seem to be "cultural" differences between groups of chimpanzees in the variety of food taken and the techniques for processing it. (West African chimps use wood and stone tools as hammers to open nuts.)

Head and body length ranges from 28 to 33 inches in females and 30-36 inches in males. Height ranges from about 3-1/4 feet to 5-1/2 feet. Weight is from 99 pounds to 176 pounds. Captives may be heavier. Arm-spread is 50% greater than height. No tail. Face bare, skin pink in infancy darkening to black in adulthood. Baldness is frequent in adults, typically a triangle on the forehead of male, more extensive in females. Hair color is black. Infants have white tail tuft and older males (20 or over) may develop grey back patch.
Geographical range:
Western and Central Africa, north of river Zaire, from Senegal to Tanzania, from 14 degrees north to 10 degrees south. Humid forest, deciduous woodland or mixed savanna; presence in open areas depends on access to evergreen fruit-producing forest. Found from sea level to 6500 feet.