updated   2006-04-26 23:23 PT

I now have now two bonobo web pages.
other one features portraits of all the apes..
And then there's the new book, a mere $14.

Pan paniscus  
alias "Pygmy Chimp"
alias "Left Bank Chimp"

William H. Calvin         

 University of Washington


Is this a monkey or an ape?


 If an ape, is it a bonobo?


Many people do not know the difference between a monkey and an ape.  Apes evolved from Old World Monkeys about 25 million years ago.  Apes are "super monkeys" in the same sense that humans are "super apes."

Compared to monkeys, apes are tailless, have very versatile shoulder joints, and have brains about twice as large.

There used to be many species of apes, but most are now extinct.  The six remaining ape species: the "lesser apes" are the gibbon and siamang.  The "great apes" are the orangutan, gorilla, chimpanzee, and bonobo.  All live quite close to the equator, in either Africa or southeast Asia and its offshore islands.  

I now have a portrait gallery of all the ape species including another identification challenge, telling the apes apart from one another.

Bonobos (the "Left Bank Chimps"), also known as pygmy chimpanzees, were the last ape species to be identified (in 1926), some three centuries after theBonobo standing on shoulders other apes were known to science.

That's because they only live in one small and shrinking place, the swampy equatorial forests of the left bank of the Congo River (common chimps are the Right Bank Chimps, extending from Tanzania and Uganda all of the way to West Africa).

Bonobos walk upright somewhat more easily than the chimps can.  Still, walking on all fours is less tiring for both bonobos and chimps.

Behaviorally, these two Pan species are our closest cousins, followed by gorilla, orangutan, gibbon, and siamang.  If you want to see a stand-in for what human ancestors looked like, and acted like, 6-7 million years ago, go and watch a band of bonobos in a zoo (lists below). 

There are good introductory bonobo webpages at the San Diego Zoo, the Columbus Zoo, and the Great Apes Trust.  The best book around on bonobos is the one by the primatologist Frans de Waal:

Bonobo: The Forgotten Ape (University of California Press 1997) with excellent photos by Frans Lanting.

Audio and video links for bonobos and chimps from Yerkes; also the Great Apes Trust.

Bonobos and chimps are our closest cousins among the apes.  One sees the reassuring arm around the shoulder, hugging and kissing.

The uncommon social structure, sexual behavior and intellectual capacity of bonobos give us a unique glimpse of the roots of human nature.

Visit the portrait gallery of all the ape species.

The Evolutionary Background

Apes last shared a common ancestor with the Old World Monkeys about 25 million years ago.  Gibbons split off about 18 million years ago and orangutans about 12-14 million years back; the gibbon lineage split off the siamangs about 2.5 million years ago.

illustration from Calvin, A Brain for All Seasons (2002)

click to order from amazon.comHumans evolved from an ape species that existed about 6 million years ago (sometimes called "Pan prior"). About 2.5 million years ago, the common chimpanzee and the bonobo became separate lineages, as did bipedal woodland apes (e.g., Australopithecines) and our Homo lineage (in white).  About 1 million years ago, both the gorilla and chimpanzee lineages split into east and west subspecies because of ice age droughts.  Extinctions are shown by terminated bars; only arrows represent extant species.

For more on human evolution, see my book, A Brain for All Seasons.  It won the 2002 Phi Beta Kappa book prize for science as literature.


The common chimps range from the East African Rift Valley to westernmost Africa. Bonobos live in the wild in only one section of the Congo River basin, right on the equator at 22 degrees East, of the Democratic Republic of Congo (ex-Zaire).    Chimp/bonobo map Bonobos have no national park, nothing to protect them from human hunting and encroachment except for the tropical diseases which limit human habitation in the area. 

One of the world's leading scientists studying bonobos in Africa says an area that once had hundreds of the apes now has fewer than two dozen and that, if conditions persist in the Wamba forest of the Democratic Republic of Congo (DRC), "bonobos will be extinct very soon."

Last week, Dr. Gen'ichi Idani of the Great Ape Research Institute (GARI) in Okayama, Japan, presented new findings from his Wamba field study to members of the American Zoo and Aquarium Association's (AZA) Bonobo Species Survival Plan Program meeting in Columbus, OH, in summer 2005.

Dr. Idani said the once bonobo-rich region of Wamba has seen a catastrophic decline in the past 10 years. Five out of six bonobo research groups have disappeared from the 150 square kilometer region. An area that held 300 bonobos now has only 22 – a 93 percent decline in the Wamba bonobo population.

According to Idani, the people of Wamba allowed bonobos to co-exist with them for generations and had a taboo against eating bonobo bushmeat. However, two wars in the past decade have had a significant influence on Wamba, its people and bonobos. Violence forced villagers to take refuge in the forest which resulted in deforestation, poaching and the eating of bushmeat.

“If we leave the Wamba forest as it is, bonobos will be extinct very soon,” says Idani. “The countdown for extinction has already begun.”

For conservation links, see the Great Apes Trust and the Bonobo Conservation Initiative.

William H. Calvin
is a
neurobiologist and the author of a dozen books on anthropology, brains, evolution,
climate, and the history of science.

To browse the books, go to the home page.

To order a copy of one of the books, click on a cover for the link to amazon.com.

A Brief History
 of the Mind, 2004

click to order from amazon.com
A Brain for All Seasons
(Phi Beta Kappa book prize)

Lingua ex Machina:  Reconciling Darwin and Chomsky with the Human Brain (Calvin & Bickerton, 2000)
Lingua ex Machina

The Cerebral Code:  Thinking a Thought in the Mosaics of the Mind (1996)
The Cerebral Code

How Brains Think:  Evolving Intelligence, Then and Now (1996)
How Brains Think

Conversations with Neil's Brain:  The Neural Nature of Thought and Language (Calvin & Ojemann, 1994)
Conversations with
Neil's Brain

The River That Flows Uphill
The River That
Flows Uphill


The Throwing Madonna:  Essays on the Brain
The Throwing Madonna

Inside the Brain

Monkey 1, 18
Baboon 20, 24.

Siamang 4, 6, 9.
Gibbon 21
Orangutan 5, 8, 17
Gorilla 2, 10, 22-23
Chimpanzee 11
Bonobo 3, 7, 12-16, 19.

Bonobo peculiarities

This is not a hand.

This is what the bonobo's foot is capable of. 

The precision grip is what we humans use to lift a small tea cup or inspect a grape.  Bonobos will use their foot to pop a grape into their mouth. 


View the BBC's excellent
video on the threat to the African apes from the bushmeat trade. 

From an earlier Cincinnati Zoo web page:

Currently, bonobo populations number less than 20,000 individuals.  This number is assumed to be dropping.  Political unrest in Zaire is preventing researchers from entering the country, and has led to the end of negotiations with the government to set aside more protected land for bonobo habitat. Previous to the war in Zaire, reserves were being patrolled regularly in order to protect existing bonobo populations from poaching. Today, the guards have left their stations because of a lack of financial support and the threat of war.  This leaves bonobos completely unprotected.  Researchers fear the worst.

An excerpt from the The Bonobo Protection Fund literature:

Bonobos are also called pygmy chimpanzees.  The name pygmy chimp was bestowed by Westerners in the 1930's, not because the animals were diminutive in size, but because they lived near human pygmies.  It is important to understand that bonobos (Pan paniscus) are not chimpanzees (Pan troglodytes).  While they share the same genus, bonobos and chimps are markedly distinct species.

The uncommon social structure, sexual behavior and intellectual capacity of bonobos reveal compelling clues about the roots of human nature.  Bonobo anatomy is eerily similar to that of our early human ancestors. Bonobos and humans share 98% of the same genes.

[The appearance of bonobos make them] the most human-like of all apes. Their stride, their stance, their resting postures, their gestures, and their facial expressions all look more like our own than those of chimpanzees, gorillas or orangutans. Often, in the forest, large groups of 200 to 300 individuals come together for what appear to be "visits." During such times, there is almost constant "talking" or vocal exchange, as though they are catching up on past gossip---however, we really do not know, as study of these apes is barely in its infancy. 
   --from the Bonobo Protection Fund

Tool use (soaking up juice with mashed end of stick)



Zoo Exhibits of Bonobos

Every zoo wants some bonobos but only a few have them because they are relatively rare and endangered. The total number of bonobos at zoos and research institutions is only about 141, worldwide (2002 numbers).  In the Democratic Republic of Congo and the Republic of Congo, there are 29 bonobos living in a sanctuary or other facilities.

Europe: Berlin (4 bonobos), Frankfurt (8), Cologne (5), Leipzig (3), Stuttgart (8), Wuppertal (5), Twycross (UK, 5), Planckendael (BE, 9), Apenheul  (NL).
Morelia (Mexico, 3 bonobos), San Diego Zoo (9) and Wild Animal Park (12), Cincinnati OH (6), Columbus OH (11), Fort Worth TX(3), Jacksonville FL, Milwaukee WI(11).  There are 71 bonobos in zoos of the U.S., 70 in Europe's zoos  In comparison, other captive ape populations in United States zoos include 350 chimpanzees, 300 western lowland gorillas, and 250 orangutans.

Unlike chimps, the hair of a
bonobo parts down the middle.

Columbus Zoo

has 11 bonobos (as of August 2000):

Adult males: 2 (Jimmy & Toby)
Adult females: 2 (Susie & Lady)
Juveniles: 1 male age 3-1/2 (Donny)
1 male age 2-1/2 (Ricky)
1 female age 1 yr (Tamia)
Mambo, a 9-year old male from the Morelia Zoo in Mexico. 
Lucy, an 11-year-old female from the Milwaukee Zoo.
Kimia, who is the daughter of Suzie and was born on June 13th, 1999, and 
Elekyia, the daughter of Lucy, born at the end of February, 2000.

Planckendael (between Brussels & Antwerp, Belgium)

A large, easily-viewed outdoor island, complete with wading opportunities for the bonobos. It is combined with an indoor space that is both interesting to the bonobos and easily seen by the visitor from either above or at floor level (access via the waterfall path).  Nine bonobos.  (Information from W. H. Calvin visit, 3 June 1995).

Travel Directions (by the author;  FYI, there is no longer any English or German on their website)

By Car: Look for Exit 11 "Hofstade" on the fast highway E19 between Brussels and Antwerp and take the road east.  It ends in another highway within a few km; turn left (north), direction Mechelen.

Watch for Planckendael signs when approaching a pedestrian crosswalk (Planckendael is an old estate on the left of the road; the parking is on the right).  Note the storks nesting in the chimneys.  The bonobos are in the Africa Project.

Leuvensesteenweg 582
2812 Muizen - Mechelen
tel. +32(0)15/41.49.21
fax. +32(0)15/42.29.35

E-mail: info@planckendael.be

By Train: To Mechelen, then bus "De Lijn" Route 285 (verify).

Planckendael is open every day of the year at 0900. The closing time varies with the season (1645 in winter, 1900 summer). The bonobos will be inside if the temperature is below 15°C, but there are two good viewing positions for their large room.

San Diego Zoo

If you haven't seen the bonobo exhibit at the main zoo for a while, you have a treat in store, as they have constructed a magnificent exhibit with four viewing perspectives.


Milwaukee Zoo

Visited April 2005, excellent exhibit of 11 bonobos.

The New York Times article of 22 April 1997, "Bonobo Society: Amicable, Amorous and Run by Females." Some quotes:

Even today there are only about 100 in zoos around the country, compared with the many thousands of chimpanzees in captivity. Bonobos are closely related to chimpanzees, but they have a more graceful and slender build, with smaller heads, slimmer necks, longer legs and less burly upper torsos. When standing or walking upright, bonobos have straighter backs than do the chimpanzees, and so assume a more humanlike posture. Far more dramatic than their physical differences are their behavioral distinctions. Bonobos are much less aggressive and hot-tempered than are chimpanzees, and are not nearly as prone to physical violence. They are less obsessed with power and status than are their chimpanzee cousins, and more consumed with Eros. As de Waal puts it in his book, "The chimpanzee resolves sexual issues with power; the bonobo resolves power issues with sex." Or more coyly, chimpanzees are from Mars, bonobos are from Venus.


The New York Times article (April 1998) on bonobo language abilities.

The New York Times article (February 1998) on bonobo symbolic communication in the wild.

Sue Savage-Rumbaugh and Roger Lewin, Kanzi (Wiley, 1994). See also the New York Times article and the book page at Amazon.com.

Sue Savage-Rumbaugh, Stuart Shanker, Talbot J. Taylor, Apes, Language, and the Human Mind (Oxford University Press, May 1998).

Frans de Waal with photos by Frans Lanting, Bonobo: The Forgotten Ape (University of California Press 1997).  As The Atlantic Monthly reviewer said:

What Professor de Waal describes is a society of mamma's boys, permanently subject to female control. It is also an erotic society, with sexual contacts conducted steadily, ingeniously, and with no discernible concern for sex or age.  One of Mr. Lanting's many photographs sums up these apes rather well. It is of a male bonobo, standing straight as a palace sentry, well prepared for sexual action, and offering handfuls of sugarcane. Bonobo may lie at the root of civilized behavior.

deWaal's other books are also relevant to bonobos and chimpanzees (and see his website at the new Living Links Center):

Frans de Waal, Good Natured: The Origins of Right and Wrong (Harvard UP 1996).

        "If carnivory was indeed the catalyst for the evolution of sharing, it is hard to escape the conclusion that human morality is steeped in animal blood. When we give money to begging strangers, ship food to starving people, or vote for measures that benefit the poor, we follow impulses shaped since the time our ancestors began to cluster around meat possessors. At the center of the original circle, we find a prize hard to get but desired by many... this small, sympathetic circle grew steadily to encompass all of humanity — if not in practice then at least in principle.... Given the circle's proposed origin, it is profoundly ironic that its expansion should culminate in a plea for vegetarianism."

Frans de Waal, Peacemaking Among Primates (Harvard UP 1989).

Frans de Waal, Chimpanzee Politics: Sex and Power Among the Apes (Johns Hopkins University Press 2000, revision of the 1982 first edition).

Frans de Waal's excellent article on bonobo sex and society (Scientific American, March 1995) has the following suggestions for further reading:

And search a bookstore such as Amazon.com for more recent books.

Please send updates from your bonobo zoo visits to

  hits since 1997

Bonobo web links