Chimpanzees are broadly omnivorous. They rely heavily on ripe fruits and young leaves, with additional consumption of stems, buds, bark, pith, seeds, and resins. This diet is supplemented by a variety of insects, small vertebrates, and eggs. Soil is sometimes consumed, especially that associated with termite mounds, presumably for the minerals it contains. Diets vary seasonally, as different foods are available at different times of year. Diets also vary geographically. Some foods eaten by chimpanzees in one location are not eaten by chimpanzees in another location, even when the food in question is present at both locations, making it possible that geographical differences in diet are cultural. (Goodall, 1986; Jones et al., 1996; Nowak, 1999; Tomasello, 1994)
Chimpanzees spend the bulk their time feeding or moving from one food source to another. Although foods may be eaten at any time of the day or night, there are typically two major peaks in feeding activities. The first occurs in the morning between 7 and 9 AM. The other is in the afternoon, between 3:30 and 7:30 PM. (Goodall, 1986; Nowak, 1999)
Chimps may use a food source until the food is gone, or they may leave before having consumed all of the food. This may depend upon how many chimps are feeding at the site. Variety in the diet seems to be important, and after consuming enough of a particular food, chimps may move on in search of something else to eat. (Goodall, 1986)
Chimpanzees are known to hunt other large vertebrates on occasion. The largest animals hunted are bush pigs (Potamochoerus larvatus), colobus monkeys (Colobinae) and baboons (Papio). Although adults are sometimes taken, it is more common for chimps to take young animals. (Boesch, 1994; Goodall, 1986; Nowak, 1999)
The predatory behaviors of chimpanzees vary between sexes, individuals, and locations. Males typically consume more meat than females, who seem to specialize more on insect foods than do males. Chimps in the Ivory Coast are known to use more cooperative hunting techniques than the chimpanzees in Tanzania and Uganda. This may be related to differences in the habitat and the behavior of prey. In the Ivory Coast, there is a well developed canopy to the forest, and monkeys may escape chimp predators by climbing high into the trees. In this situation, only cooperative hunting tactics work well for capturing prey. However, at both Gombe and Mahale in Tanzania, the forest is not as dense, and the upper portions of the canopy are not as well developed. As a result, individuals have high success at hunting without enlisting the aid of other chimps. (Boesch, 1994)
Another consequence of habitat differences between western and eastern populations of chimpanzees is that in the east, the colobus monkeys preyed cannot take refuge in areas inacessible to chimpanzees. Under these conditions, colobus monkeys are more aggressive toward the chimpanzees. Coupled with the smaller size of the subspecies of chimp found in this area (P. t. schweinfurthi), a different dynamic is established between predator and prey. Chimpanzees in this area are sometimes fearful of adult male monkeys, and are most likely to attack females with young, in the hope of snatching a baby monkey to eat. (Boesch, 1994)
Cannibalism has been reported in chimpanzees. The circumstances under which this behavior has been observed vary, although typically chimps do not kill and eat members of their own communities. Most commonly, infants killed during intercommunity aggression may be eaten by the males of the neighboring community. However, in a famous case at Gombe, an adult female and her adolescent daughter were responsible for killing several infants of other females in their community. These infants were eaten, often in front of the mother. This behavior ended when the adult female died. The daughter has shown no inclination toward cannibalism since her mother's death. (Goodall, 1986)
Captive chimps commonly exhibit coprophagy and repetitive regurgitation and reingestion. These behaviors appear to be an aberration seen in captivity, as they are not found in wild chimpanzees. (Goodall, 1986)
Finally, sick chimpanzees are known to consume a variety of plants with potentially medicinal value. For a more comprehensive discussion of this behavior, please refer to the behavior section. (Huffman and Wrangham, 1994)
- Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.
- Goodall, J. 1986. The Chimpanzees of Gombe: Patterns of Behavior. Cambridge, Massachusetts: The Belknap Press of Harvard University Press.