Chimpanzees

Chimpanzees

Chimpanzee Society

David Graybeard, a gentle and kind adult male, was the first to begin a new level of trust…

One day, as I sat near him at the bank of the tiny trickle of crystal-clear water, I saw a ripe red palm nut lying on the ground. I picked it up and held it out to him on my open palm. He turned his head away. When I moved my hand closer he looked at it, and then at me, and then he took the fruit, and at the same time held my hand firmly and gently with his own. As I sat motionless he released my hand, looked down at the nut, and dropped it to the ground. At that moment there was no need of any scientific knowledge to understand his communication of reassurance. The soft pressure of his fingers spoke to me not through my intellect but through a more primitive emotional channel: the barrier of untold centuries which has grown up during the separate evolution of man and chimpanzee was, for those few seconds, broken down. —Jane Goodall, In the Shadow of Man, p. 251

Family and social Life

Chimpanzee mom and baby in the forest
Chimpanzees enjoying forest life
Photo: © NEAVS

Chimpanzees’ complex family and social interactions are extremely important to them. What follows are astounding details of their family life, distinctive culture, and social interaction. Their needs in these areas contrast sharply with the barren and often isolated lives so many live in U.S. laboratories.

Family life

Family relationships are vital to chimpanzees. They live in extended family groups of as many as 20-120 individuals.1,2 They have a fission-fusion social organization in that they break off into smaller interchangeable groups and periodically come together. The hunter-gatherer lifestyle of early human communities is thought to resemble that of chimpanzees.3

Chimpanzees and humans both reach sexual maturity in their early teens. In the wild, female chimpanzees typically give birth only once every five years, usually to one baby. Infant chimpanzees are reared by their mothers and have close relationships with related females and older siblings, who often share in their care. Infants are extremely important. If a mother is injured or dies, others will take on the role.9 Jane Goodall, the famous primatologist, noted this on many occasions including when Sniff, a young male, adopted his baby sister after their mother’s death.

Mothers and sons typically have lifelong bonds, as do other individuals within an extended social group. Upon reaching sexual maturity, females migrate to neighboring communities while males stay in their natal group. Sometimes females will migrate to mate but return to their natal group. Because chimpanzees have babies only once every five or six years, mothers are able to nurture and teach their children intimately. Babies are not weaned until they are about five years old, and remain close to their mothers for the first decade of their lives.9

Most free-living chimpanzee mothers have only about three children in their lifetime; twins are rare.9 (To read how this contrasts sharply with breeding in labs, read Lab Life Traumas.)

If a chimpanzee mother falls ill, older siblings or other females in the group will tend to the sick mother’s child.9 Some very young chimpanzees have been known to die of grief when their mother dies. In other situations, the adopted young fare well in the care of older adults. However, if a sibling who adopts the infant/child is too young and unable to provide nutrition and proper care; the infant can die as well.

Sniff, a member of the chimpanzee family that Jane Goodall spent decades studying, adopted his sister after their mother’s death:

During the two weeks that Sorema survived her mother she was carried everywhere by her six year old brother Sniff. It was a touching sight to see the juvenile male moving about with his tiny sister, pressing her against his breast with one hand, cuddling and grooming her. When they came to camp Sorema they ate bananas, but it was milk she needed, and each day she seemed weaker and her eyes looked bigger. Then, one morning, Sniff came into the feeding area cradling her dead body.

           —Jane Goodall, In the Shadow of Man, p. 218

While fathers and mothers don’t form monogamous bonds for life, the males in a group play with the children and protect them. Whether or not they are biological fathers, males in the group play important roles in the lives of the young.7

Chimpanzee culture

Jane Goodall and chimpanzee friends in forest
Dr. Jane Goodall and chimpanzee friends
Photo: © Michael Nichols from Brutal Kinship (Aperture)

Chimpanzees live, eat, hunt, and play communally in groups of 20 or 30 individuals or up to several dozen individuals. They call to each other to announce the presence of certain foods or the imminent danger of a predator. They have different warning calls for different predators, as one example of their rich language of calls and vocal expressions. Their range of sounds expresses everything from excitement to contentment to fear to joy.10

…and of the chimpanzee Flo
Flo sometimes coped with the task of wrestling Flint from his playmates by playing with him herself. Then when she dragged him away by one foot, he apparently continued to regard it as a game, for he laughed as his back went bump, bump, bump over the uneven ground. I was reminded of Christopher Robin dragging Pooh Bear downstairs.

          —Jane Goodall, In the Shadow of Man, p. 156

Chimpanzees learn from each other: how to make a “night nest” (bed), play, or which plants to eat for medicinal purposes. Through imitation and observation they learn to make and use tools to crack open nuts, fish insects out of a tree trunk or termite mound, use leaves as sponges, and use objects as weapons.8 These behaviors are handed down from generation to generation and can vary from one group to another. Passing traditions down through generations reflects a simple form of culture.4

Touching and grooming are extremely important for chimpanzees. Chimpanzees will present their backs, a sign of trust, to someone with whom they feel safe, seek to bond with or otherwise be in relationship with. Some groom slowly and methodically. Some sort through the other’s hair, probing, picking and stroking. Others groom frenetically.4 But the root of the behavior is the same: a means to deep bonding. These tactile rituals calm tensions and foster relationships. Chimpanzees embrace each other as a greeting or for comfort or consolation.5 They show enormous capacity for relationship, trust, commitment and caring—the glues of all societies.

For bonobos (or pygmy chimpanzees), sexual contact fulfills a panacea of social needs. It is used for pleasure, for avoiding conflict, for reconciliation, for appeasing, to divert attention, for bonding, for procreation—its role in their society is as myriad, or perhaps even more so, than in human societies.6

Chimpanzees and humans have complex daily lives. As with human primates, their emotions and behaviors run the gamut from kissing and nurturing to fighting and reconciling to killing. They are territorial, loyal, altruistic, affectionate, intelligent, and can also be dishonest, manipulative, unfair or violent. The complexities that accompany our emotional repertoire exist for theirs as well.

Chimpanzee communities

Chimpanzees search for food communally when foraging or hunting prey. A group of males will chase, corner, and kill small monkeys for meat.7 Groups will sit together for hours, “fishing” termite mounds or enjoying the ripened fruits of trees.9

Chimpanzees acknowledge and respect a hierarchy within their groups. Dominance relationships are influenced by alliances, and coalitions are formed by males—chimpanzee politics. They will attack trespassing males from another territory to defend their own.7

Social groups consist of a dominant male, adult females and subordinate males and juveniles.7 As they reach maturity, some younger males challenge the dominance of the leader. Groups consist of several generations.


Sources

[1] Nishida, T. (1968). The social group of wild chimpanzees in the Mahale Mountains. Primates, 9, 167-224.

[2] Goodall, J. (1986). The Chimpanzees of Gombe. Cambridge, MA: Belknap Press.

[3] Stanford, Craig. (1995) “Chimpanzee Hunting Behavior and Human Evolution,” American Scientist, (May-June) : 256-261.

[4] Briggs, Helen. (2001) “Cultural Habits of Chimps,” BBC News Online, Aug. 10, 2001. Available at http://news.bbc.co.uk/1/low/sci/tech/1484261.stm

[5] Bright, Michael. Intelligence in Animals, London: Toucan Books/Reader’s Digest, 1994.

[6] Boesch, C., Hohmann, G., Marchant, L. (2002). Behavioural Diversity in Chimpanzees and Bonobos. Cambridge: Cambridge University Press. 

[7] Ross, Ben. “The Human-Chimp Connection,” Available at www.benross.net/chimp.htm

[8] “Learn About Free-Living Chimpanzees.” Chimpanzee and Human Communication Institute (2004). Available at http://www.friendsofwashoe.org/learn/free_living/

[9] “Tool Use, Hunting, and Other Discoveries” Jane Goodall Institute. Available at http://www.janegoodall.org/chimpanzees/tool-use-hunting-other-discoveries

[10] “Communication.” Jane Goodall Institute. Available at http://www.janegoodall.org/chimpanzees/communication

 

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