Chimpanzees
Chimpanzees are intelligent and emotionally complex primates known for exhibiting many traits similar to humans. They belong to two species: the common chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). Physically, they have powerful arms and shoulders and primarily move using knuckle-walking, although they can also walk upright and swing through trees. Chimpanzees are omnivorous, with a diet that includes fruits, leaves, insects, and occasionally small mammals, and they have adapted their foraging strategies to their limited habitats across equatorial Africa.
Living in fission-fusion communities, chimpanzee social structures are dynamic, with membership changing throughout the day. Dominance hierarchies influence access to resources and mates, while social grooming fosters intimate relationships and community bonds. Learning is a significant aspect of their behavior, with tool use being a notable skill, especially among common chimpanzees. Emotional connections are vital to their community life, as individuals engage in behaviors such as touching and embracing to maintain social cohesion. Overall, chimpanzees demonstrate sophisticated social interactions and cultural elements that reflect their adaptability and intelligence.
Chimpanzees
Chimpanzee Facts
Classification:
- Kingdom: Animalia
- Subkingdom: Metazoa
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Mammalia
- Subclass: Eutheria
- Order: Primates
- Suborder: Anthropoidea
- Family:Hominidae
- Genus and species:Pan troglodytes (common or woodland chimpanzee), P. paniscus (bonobo)
- Geographical location: Africa; P. troglodytes is found from west to east Africa, from Senegal to Tanzania, including the Ivory Coast, Gabon, Sierra Leone, Congo Republic, and the Democratic Republic of the Congo; P. piniscus is found in the central and western regions of the Democratic Republic of the Congo
- Habitat:P. piniscus prefers rain forests and swampy forested areas; P. troglodytes has been observed in diverse habitats—tropical rain forest, wooded savanna, primary and secondary forest
- Gestational period: 7.5 to 8 months
- Life span: Forty to fifty years
- Special anatomy: Large complex brain (390 cubic centimeters average) in relation to body size
Chimpanzees are highly intelligent and emotional animals. They demonstrate many humanlike traits, such as a rudimentary culture, in their adaptive responses to environmental challenges.
Physical Characteristics of Chimpanzees
Woodland chimpanzees weigh between 73 and 132 pounds. The bonobo weighs from seventy-three to ninety-nine pounds. Females are about 10 percent smaller than males. Chimpanzees have powerful arms and shoulders and locomote through knuckle-walking, a form of quadrupedalism, although they are occasionally bipedal, and can also brachiate (swing through trees and branches). Chimpanzee forelimbs (arms) are longer than their hindlimbs. Vision is in color and highly acute. Chimpanzees have short thumbs, and their grasping ability is somewhat impaired relative to humans.
Both Pan troglodytes and Pan piniscus are promiscuous. Females of each species exhibit sexual swelling when they are receptive to mating; however, there is no consistent breeding season.
Ecology and Diet
Chimpanzees at one time inhabited a three-thousand mile belt across equatorial Africa. Today their distribution is limited, and in some regions they are extinct or disappearing.
Chimpanzee home ranges vary in size depending upon food resources and other ecological dynamics. The home range of the woodland chimpanzee can be from 2 to 215 square miles, whereas the bonobo’s home range is from 7 to 19 square miles. Water availability, nesting trees, and seasonal food resources define ranges, and chimpanzees can cover several miles in a day. Adult male chimpanzees patrol their ranges to ensure the exclusiveness of a community’s domain. Aggression as a result of invasion and intercommunity destruction has been documented by Jane Goodall.
Chimpanzees are omnivorous: Their diet consists of a great variety of vegetal foods, as well as insects, grubs, bird eggs, and small mammals. While leaves and fruit define much of the chimpanzee’s diet, colobus monkeys, young bush bucks, and young baboons obtain supplemental protein through cooperative hunts.
Group Life and Learning
Chimpanzees of both species reside in fission-fusion communities. Membership within community subgroups can change throughout the day. Males and females strive to attain dominance, or elevated status, which provides access to preferred food resources and desirable mates. Physical size, strength, and age influence the attainment of position within a dominance hierarchy. Hierarchies function to minimize chaos within the community. Woodland chimpanzee communities range from 20 to over 100; bonobo groups range from 50 to 120 individuals.
Social interaction is enhanced on the individual level through social grooming. Mutual grooming, or cleaning the hair carefully, is an act denoting friendship and intimacy.
Learning accounts for much of chimpanzee behavior, acquired through play and observation. Tool use, a learned behavior, has been observed frequently among woodland chimpanzees, much less so among the bonobo. Tools (sticks, rocks, branches, leaves) have been used, and in some instances modified, in order to access and extract underground termites from their nests for consumption; to intimidate other animals; to facilitate drinking; to clean the body; and to crack open nuts.
Chimpanzee behaviors associated with meat eating include begging and the subsequent sharing of the kill by the hunters. Cannibalism and infanticide among chimpanzees have also been observed.
Chimpanzees are emotional animals that require reassurance that they are part of the community. Touching and embracing among individuals are common behaviors.
Principal Terms
dominance hierarchy: ranking or status system found in some primate societies
fusion-fission community: a society whose members are of both sexes and all ages, which can form and dissolve subgroupings
home range: a primate’s territory
knuckle-walking: terrestrial locomotion, in which the animal walks on the knuckles of the forelimbs and soles of the hind feet
social grooming: an activity maintaining social interaction, whereby debris is removed from a primate’s hair
Bibliography
Goodall, Jane. The Chimpanzees of Gombe: Patterns of Behavior. Cambridge: Belknap P of Harvard UP, 1986. Print.
Goodall, Jane. Through a Window. Boston: Houghton, 1990. Print.
Halloran, Andrew R. The Song of the Ape: Understanding the Languages of Chimpanzees. New York: St. Martin's, 2012. Print.
Nishida, Toshisada. The Chimpanzees of the Lakeshore: Natural History and Culture at Mahale. Cambridge: Cambridge UP, 2012. Print.
Stanford, Craig B. “The Social Behavior of Chimpanzees and Bonobos: Empirical Evidence and Shifting Assumptions.” Current Anthropology 39 (1998): 399–420. Print.
Goodall, Jane. “To Catch a Colobus.” Natural History Magazine 104 (1995): 48–54. Print.
Waal, Frans de. Good Natured: The Origins of Right and Wrong in Humans and Other Animals. Cambridge: Harvard UP, 1996. Print.