Chimpanzee CultureChimpanzee CultureChimpanzee CultureChimpanzee Culture

Evidence and InterpretationEvidence and Interpretation

Groups studied in pthe comparative analysis of chimpanzeechimpanzee culture

Source: “Cultures in Chimpanzees”Nature, 399, 682-685 (1999)

Chimpanzee CulturesChimpanzee CulturesChimpanzee CulturesChimpanzee Cultures

An examination of 6 chimp research sitesAn examination of 6 chimp research sitesAn examination of 6 chimp research sitesAn examination of 6 chimp research sites39 behaviors were found to be either39 behaviors were found to be either

t ( i t l tt ( i t l t–– customary (occurs in at least one age or sex customary (occurs in at least one age or sex group) orgroup) orhabitual ( occurs repeatedly in severalhabitual ( occurs repeatedly in several–– habitual ( occurs repeatedly in several habitual ( occurs repeatedly in several individuals)individuals)

These 39 behaviors did not exist in allThese 39 behaviors did not exist in allThese 39 behaviors did not exist in all These 39 behaviors did not exist in all chimp groupschimp groups

Type of Cultural BehaviorType of Cultural BehaviorType of Cultural BehaviorType of Cultural Behavior

Tool use: stones or branches for crackingTool use: stones or branches for crackingTool use: stones or branches for cracking Tool use: stones or branches for cracking nutsnutsSocial: greetings rain dances invitationsSocial: greetings rain dances invitationsSocial: greetings, rain dances, invitations Social: greetings, rain dances, invitations to groom, and invitations to playto groom, and invitations to playP l h i f ti k d lP l h i f ti k d lPersonal hygiene: use of sticks and leaves Personal hygiene: use of sticks and leaves to clean body.to clean body.Medical: use of plants to treat parasites Medical: use of plants to treat parasites and infectionsand infections

InterpretationsInterpretationsInterpretationsInterpretations

Some behaviors did not exist forSome behaviors did not exist forSome behaviors did not exist for Some behaviors did not exist for ecological reasons. For example, use of ecological reasons. For example, use of stones to smash or crack nut is found only stones to smash or crack nut is found only yyin areas where stones exist.in areas where stones exist.Behaviors unique to one group are clearly Behaviors unique to one group are clearly q g p yq g p ya consequence of cultural transmissiona consequence of cultural transmissionBehaviors common to several groups may Behaviors common to several groups may g p yg p ybe a consequence of common ancestry, be a consequence of common ancestry, independent invention, or diffusion independent invention, or diffusion (f l i b t )(f l i b t )(females moving between groups).(females moving between groups).

Mechanisms of Transmission: Mechanisms of Transmission: T hi d L iT hi d L iTeaching and LearningTeaching and Learning

Facilitation (stimulus enhancement)Facilitation (stimulus enhancement): leaving nuts, : leaving nuts, ( )( ) gganvil, and hammer in view of offspringanvil, and hammer in view of offspringActive teaching (social enhancement): Active teaching (social enhancement): a mother does a mother does the behavior slowly so youngster can observe. Asthe behavior slowly so youngster can observe. Asthe behavior slowly so youngster can observe. As the behavior slowly so youngster can observe. As youngster tries, repositioning of hand or nuts by mother. youngster tries, repositioning of hand or nuts by mother. This is very rare. (Recent theory suggests that even This is very rare. (Recent theory suggests that even thought this may occur the youngster receives no feedthought this may occur the youngster receives no feed--thought this may occur the youngster receives no feedthought this may occur the youngster receives no feedback from teacher.)back from teacher.)Highly socialHighly social chimps appear to have greater cultural chimps appear to have greater cultural repertoires because they interact more than solitaryrepertoires because they interact more than solitaryrepertoires because they interact more than solitary repertoires because they interact more than solitary orangs.orangs.Diffusion of cultureDiffusion of culture: immigrant mother teaches infant : immigrant mother teaches infant t l i t h i h l d i t lt l i t h i h l d i t ltool using techniques she learned in natal grouptool using techniques she learned in natal group

Types of LearningTypes of LearningTypes of LearningTypes of Learning

Emulation:Emulation: a rough replication of thea rough replication of theEmulation:Emulation: a rough replication of the a rough replication of the behavior.behavior.ImitationImitation: precise replication of the: precise replication of theImitationImitation: precise replication of the : precise replication of the behaviorbehavior

Chimps appear to always emulate while Chimps appear to always emulate while human children imitate. Rake example.human children imitate. Rake example.

Tool use is a critical adaptation Tool use is a critical adaptation f fff ffenhancing feeding efficiencyenhancing feeding efficiency

In the Taï forest mother chimpanzees teach theirIn the Taï forest mother chimpanzees teach theirIn the Taï forest mother chimpanzees teach their In the Taï forest mother chimpanzees teach their infants the tasty art of nut cracking [the nut is infants the tasty art of nut cracking [the nut is Panda oleosaPanda oleosa] , which takes about seven years ] , which takes about seven years to masterto master——it takes about 2,200 pounds (1,000 it takes about 2,200 pounds (1,000 kilograms) of skillfully applied force to split the kilograms) of skillfully applied force to split the

t ith t l i i it B t F b dt ith t l i i it B t F b dnut without pulverizing it. Between February and nut without pulverizing it. Between February and August, the prime nutAugust, the prime nut--cracking season, a cracking season, a practiced chimp can break open more than 100practiced chimp can break open more than 100practiced chimp can break open more than 100 practiced chimp can break open more than 100 nuts per day obtaining a nutritional kick of 3,000 nuts per day obtaining a nutritional kick of 3,000 calories. calories.

Source National Geographic: http://news.nationalgeographic.com/news/2002/05/0523_020523_0523TVchimps.html

Chimp Nut CrackingChimp Nut CrackingChimp Nut CrackingChimp Nut Cracking

Sponging and MashingSponging and MashingSponging and MashingSponging and Mashing

Figure 3 shows a compound tool

Termite ToolTermite ToolTermite ToolTermite Tool

ChimpChimpChimp Chimp archaeology: archaeology: 4 3004 3004,300 year 4,300 year old toolsold tools

Macrader et al., 2007 PNAS

Chimpanzee Spear HuntingChimpanzee Spear HuntingChimpanzee Spear HuntingChimpanzee Spear Hunting

“Savanna Chimpanzees,Pan troglodytes verus,

Figure 2 Tip of Hunting

g y ,Hunt with Tools”Jill D. Pruetz and Paco Bertolani. Current Biology 17, 1–6, March 6, 2007

Figure 2. Tip of Hunting Tool Sharpened with teeth

Tool length approximately 70 cm.

Bush Baby (Bush Baby (Galago senegalensisGalago senegalensis): prey of ): prey of hihichimp spearschimp spears

Chimpanzee MedicineChimpanzee MedicineChimpanzee MedicineChimpanzee MedicineConsumption of bitter plants to relieve constipation.Consumption of bitter plants to relieve constipation.p p pp p pThe pith of The pith of Vernonia amygdalinaVernonia amygdalina is used both by chimps is used both by chimps and humans (WaTongwe) as cures for a variety of and humans (WaTongwe) as cures for a variety of bacterial and parasitic infectionsbacterial and parasitic infectionsbacterial and parasitic infectionsbacterial and parasitic infections–– Infection of parasites drops noticeably after chewing of Infection of parasites drops noticeably after chewing of Vernonia Vernonia

amygdalinaamygdalina pith. Chemical analyses has revealed sesquiterpene pith. Chemical analyses has revealed sesquiterpene lactones and new steroid glucosides with antiparasitic activity lactones and new steroid glucosides with antiparasitic activity against against SchistosomaSchistosoma, , PlasmodiumPlasmodium and and LeishmaniaLeishmania..

Ill chimps swallow whole leave with bristly undersides Ill chimps swallow whole leave with bristly undersides which “scrub” their intestinal tract by mechanically picking which “scrub” their intestinal tract by mechanically picking y y p gy y p gup intestinal worms.up intestinal worms.Capuchin monkeys have developed their own insect Capuchin monkeys have developed their own insect repellent; by squirting millipede innards or rub particularrepellent; by squirting millipede innards or rub particularrepellent; by squirting millipede innards or rub particular repellent; by squirting millipede innards or rub particular leaves over themselves and each other.leaves over themselves and each other.

Hand clasp Hand clasp iigrooming grooming

style: a style: a culturally culturally

transmittedtransmittedsocial social

conventionconventionconventionconvention

ChimpChimpChimp Chimp Infant CareInfant Care