New Chimps

New Chimps

Don't believe everything you hear about imitation, learning from mom....... There is an overabundance of uncritical anthropomorphism.(attributing human attributes to non-humans) in this video. Later we will see more on each of these two different chimp species.

There is also no sound track in the rain forest! You do see several of the authors of chapters in TO (e.g. Wrangham, Stanford)

types of chimps: common and bonobo

These are closely related but with some obvious physical differences. Bonobos -- sometimes referred to as pygmy chimps -- are more graceful looking (more like us!) and are a bit smaller. They also are much less common and less studied. Kanzi is a bonobo as was one of Yerkes' chimps. Bonobos are NOT historically closer genetically to humans than common chimps. Similarities are either inherited from a common ancestor, or the result of some divergence or convergence in evolution since a common human-chimp ancestor 5-7mya. Common chimps and bonobos had a common ancestor about 2-3 mya.

Similarly, saying chimps and humans have 97% genes in common isn’t very useful in itself. I've heard we humans share 70% with watermelons.

 Both species share a promiscuous life style, most males mating with most females, moderated somewhat by dominance. In many other social-sexual behaviors, the species differ.

Tool use and “War”, for example have not been seen in bonobos, but are common in chimps. And bonobo groups may have a dominant female leader, something never seen in the more aggressive common chimp groups.


Chimps are found in a band across central Africa, from west to east.  Bonobos very limited to the Congo basin. Their habitat, being relatively isolated, probably allowed bonobos to evolve a lesser aggressive society as females preferred more and more to mate with lower testosteroned males.

study sites

Tai forest, Zaire (now Democratic Republic of Congo), Gombe


Goodall's group (one reproduced 6 offspring -- a large number for a chimp).
males stay in group (females leave)
paramilitary patrol and war (see reading)

pant hoots in Tanzania

the problem of meaning --"Gavagai" -- what do these calls mean? How do we learn our human words?
puppetmaster metaphor-- can these calls really convey lots of information? Important stuff yes, lots of it --doubtful. See the Language video on this too where Lieberman notes how fast human speech can be.

The researcher interviewed about her research is appropriately cautious in her conclusions.

male display and aggression

Common chimp males seem much more aggressive than bonobos whereas bonobo females are more powerful, perhaps due to social bonds among them which may be related to availability of the preferred bonobo diet.  Goodall somewhere refers to male chimps as “thugs” --and singles out Frodo as a real brute. (He later became the dominant male in her F-group.)

dominance and food

give me monkey meat!

While hunting plays a relatively small role in common chimps' food supply, they might prefer to have more if they could get it. See readings (especially by C. Stanford, shown in the video) for more ideas on the significance of meat (e.g. males trading eat for sex with females.)

Only common chimps appear to systematically hunt mammals-- especially colobus monkeys.

evolution of human meat eating?

Can chimp behavior tell us anything about this?  It is evident they like meat but it is only a small fraction of their diet. Meat, including seafood, was probably critical to the evolution and development of the larger human brain.

minimally cooperative hunting

This is probably a function of the situation.

individual differences in hunting

Frodo gets 10% of all kills

(But the dominant male gets the meat.) An example of incipient adaptation if Frodo's hunting ability is spread throughout the population. Frodo did become the alpha male in large part due to his strength. (See Goodall's Return to Gombe video later when we will see his demise as dominant male.)

Tai (Boesch)

cooperative hunting a result of environment

More difficult for individual chimp to catch monkey ; here they drive a monkey into the waiting chimps on the ground and others "blocking" its escape. The forest setting requires more cooperation, apparently..  Every male must do its share of work to share in meat.  This leads to a different social interaction over the meat. Once more, we see an example of how the environment shapes behavior and ultimately body features via natural selection.


Traditionally play is seen as a kind of practice and exercise of adult movements

infantcide and cannibalism

A dominant male kills infant and they all eat it; see the recent paper on "furtive mating....." An older idea is that these males are just eliminating the competition early when they can't fight back. This was based on data supposedly showing it was primarily male infants killed. (See Itani, 1985).  Narrator says they eat the young chimp as if it were a monkey; maybe they are confused!!!

Congo, Zaire bonobos

(Bonobos are chimps with a closer physical resemblance to humans probably due to their neotenous condition relative to common chimps. They are not closer historically. See upcoming video "The uncommon chimp" and reading by de Waal.)
Note somewhat prominent breasts, feeding chewed food, upright posture with ape- like pelvic walk, use of sex and extended receptive periods in female. (See my photo of a nursing bonobo at the San Diego zoo.)

Prominent breasts in humans apparently serve some additional functions not linked to feeding infants?

These bonobos, while certainly capable of tool use, have not been observed to do so in their natural habitat. This is perhaps due to the nature and availability of their diet--largely herbs and grasses. Their food availability may also impact their social/sexual behaviors since female bonobos do not have to separate from the group to feed.


A f emale can be the dominant individual in a bonbo group; they are close to their sons who stay in the group all their lives (young females leave the group in both chimp species).  A male bonobo’s rank is in part a function of his mother’s rank.

The bonobo peacefulness seems a result of their food preferences-- plentiful greens -- and isolated environment. Aggression may not be necessary and there are reports bonobo males have lower testosterone levels than those of common chimps. (This may be a genetic adaptation or result of lower stress environments or both.) Females probably mated more with the lower testosterone level males.

For more info, see Also search the Primate News.

This video also acknowledges the considerable effort made by Japanese primatologists including Dr. Kano, in Africa. (They also were responsible for the discovery of traditions in their Japanese macaques shown in Life in The Trees-- the famous Imo who washed her potatoes and separated rice from sand.)

nutcracking in Tai forest

These are common chimps, observed by the Boesches.  There are issues to  consider here; first of all, Darwin wrote about this over a hundred years ago.  While a human might take a long time to crack the first few nuts, I be that within a few weeks there would be a system to speed up the process.

Do mothers really “teach” offspring?  Why  do females seem to develop and maybe transmit knowledge of nut cracking?

Boesch relates an anecdote about an anthropologist taking 45 minutes to get the meat from 3 nuts. But I'd bet he or she would figure out better tools and methods as needed.
Chimps seem to have little tendency to progress and become more efficient at tasks. A report in the Primate News claims rocks dated at over 4000 years ago, were used by chimps to crack nuts. That is nothing to brag about when we contrast the progress humans have made in "tools" over that period.dddddd

Wrangham (see readings)

tool using at various locales (culture/environment?)

See video coming soon.

ant eating variation


getting marrow

"medical" plants?

In all of this video, don't get overly anthropomorphic-- i.e. attribute human motives and intentions to nonhumans. While this may be helpful in predicting behavior (probably its origin in human nature), it can be misleading without other evidence.


gestures, facial expressions


Goodall on conservation


human poachers

other natural causes

death rituals?

Anthropmorphism -- attribution of human features to nonhumans? It is human nature-- see the literature on "theory of mind" that originated with David Premack and his chimp studies.