[VIDEO] Why Bonobos Don’t Kill Each Other

July 2, 2010


Brian Hare, an assistant professor at the Duke Institute for Brain Sciences at Duke University, and Vanessa Woods, a research scientist in the Department of Evolutionary Anthropology at Duke, do comparative studies on the cognitive development of bonobo apes, chimpanzees and humans. Ms. Woods, 33, a former journalist from Australia, has just published a book about their marriage and work, “Bonobo Handshake: A Memoir of Love and Adventure in the Congo.” We spoke last month after they had appeared at the World Science Festival in New York City. An edited version of the conversation follows:


A. Vanessa: By a series of happy accidents. For much of my 20s, I didn’t know what I wanted to do with my life. So I went to Africa and did a little of everything. I worked with chimpanzees for a bit and then I did a little bit of filming and I worked a bit on children’s books.

When I met Brian in 2004, I was 27 and volunteering at a chimp sanctuary in Uganda. Brian was testing the chimpanzees’ capacity for cooperation and sharing.

Then Brian got invited to the Congo to perform the same experiments on bonobos, our other close ape relations. Would I come along as a helpmate? I hated the idea. My mother, the world’s biggest feminist, always said, “Never follow a man — do your own thing.” I knew almost nothing about bonobos. I thought: “Aren’t those the apes that have a lot of sex?”

Brian: That’s what most people know about bonobos: they have a lot of sex. That’s not what’s interesting about them. The No. 1 reason they are interesting is that they don’t kill each other. The question I was in Africa chasing was: why will a chimp get into a severe fight with another — perhaps kill or maim it — while a bonobo, in the same situation, won’t? I’m basically an anthropologist. And in looking at the psychological and social propensities of our close relatives, learning about their differences in behavior, maybe we’ll be able to make some inferences about what happened during human evolution.


A. Brian: The type of experiments that developmental psychologists try on human subjects to see how they’d behave in certain situations. With the apes, I designed tests and games where they could obtain treats — apples, bananas — if they engaged in acts of cooperation.

The chimps, it turned out, would only cooperate if they were teamed up with others of equal status. If you put them with subordinate or superior status chimps, they became intolerant. When you had equal-status chimps together on a test, they were able to solve conflicts of interest, negotiate successfully and recruit collaborators. But when we changed one simple thing, we’d crush their ability to cooperate. We took separate piles of treats and combined them into one. Immediately, the chimpanzees started competing with each other and all cooperation fell apart.

Later, when we were in the Congo, we posed the same question to the bonobos. The piles of food were merged. No problem. Everyone shared. My doctoral thesis adviser at Harvard, Richard Wrangham, thinks this may be because chimpanzees evolved in a situation of food scarcity while bonobos developed in the giant salad bowl of the Congo basin where there was abundance.

Vanessa: Another thing: bonobos are matriarchal. If it’s usual for female chimps to get pushed around and battered by males, bonobo females run things. Once, while in the Congo, I witnessed Tatango, this young male bonobo, start to do what the chimps in Uganda regularly did: he went up to the alpha female, Mimi, and backhanded her across the face. She gave him the most withering look. Within seconds, five unrelated females chased him into the forest. Poor guy. They almost took his testicles off. After that, he never made another problem. Bonobo females seem to know that if they stick together, the males can’t dominate.

Brian’s gender was actually a problem when we first arrived in the Congo. He walked right up to the bonobos, did all these loud displays, which usually fascinates chimpanzees and makes them want to play with you. The male bonobos were terrified of Brian and the female ones would have nothing to do with him. I had to run the experiments because they seemed to accept me more easily. Once that became clear, my role became larger than that of a “helpmate.” With time, the work became mine, too.


A. Brian: Well, we went to the semiwild. There’s this amazing conservationist, Claudine Andre, who founded a sanctuary in Kinshasa for bonobos orphaned by the bush meat trade. She’d convinced the Congolese to let her use this 100-acre wood with lily ponds and forests that once had been a bucolic retreat for Mobutu Sese Seko.

Working with the orphans in the sanctuary, they were much more like wild animals than the captive bonobos one might study at a zoo. They were obviously much easier to see and interact with than animals in the forest.


A. Brian: Tentative answers. The research is ongoing. Some of the differences between chimps and bonobos have to do with what happens to them during their development. Essentially bonobos and chimps have similar behaviors as youngsters. Like bonobos, juvenile chimps are very tolerant, peaceful. When they go through puberty, they change. So what happens to adolescent bonobos? Nothing! They don’t change. Their levels of play, their levels of sharing and sex, it all keeps going. They are Peter Pans.


A. Vanessa: Very. There are probably about 10,000 remaining in the wild. Nobody really knows. It’s hard to get in there and count them all.

There’s very little agriculture in the Congo. And a lot of hunting. Bush meat is how people get their protein. And unfortunately, bonobos are really prized meat for hunters because they live in communities. If you’ve found one, you’ve found thirty that you can shoot and kill all at the same time. Of course, bonobos aren’t the answer to feeding the Congolese people. There are 68 million Congolese and 10,000 bonobos. The people need aid, some kind of agricultural program so that the farming becomes sustainable, and peace.

Bonobo Society: Amicable, Amorous and Run by Females


Nature’s raucous bestiary rarely serves up good role models for human behavior, unless you happen to work on the trading floor of the New York Stock Exchange. But there is one creature that stands out from the chest-thumping masses as an example of amicability, sensitivity and, well, humaneness: a little-known ape called the bonobo, or, less accurately, the pygmy chimpanzee. Before bonobos can be fully appreciated, however, two human prejudices must be overcome. The first is, fellows, the female bonobo is the dominant sex, though the dominance is so mild and unobnoxious that some researchers view bonobo society as a matter of “co-dominance,” or equality between the sexes. Fancy that.

The second hurdle is human squeamishness about what in the 80s were called PDAs, or public displays of affection, in this case very graphic ones. Bonobos lubricate the gears of social harmony with sex, in all possible permutations and combinations: males with females, males with males, females with females, and even infants with adults. The sexual acts include intercourse, genital-to-genital rubbing, oral sex, mutual masturbation and even a practice that people once thought they had a patent on: French kissing.

Bonobos use sex to appease, to bond, to make up after a fight, to ease tensions, to cement alliances. Humans generally wait until after a nice meal to make love; bonobos do it beorehand, to alleviate the stress and competitiveness often seen among animals when they encounter a source of food.

Lest this all sound like a nonstop Caligulean orgy, Dr. Frans de Waal, a primatologist at Emory University in Atlanta who is the author of “Bonobo: The Forgotten Ape,” emphasizes otherwise. “Sex is there, it’s pervasive, it’s critical, and bonobo society would collapse without it,” he said in an interview. “But it’s not what people think it is. It’s not driven by orgasm or seeking release. Nor is it often reproductively driven. Sex for a bonobo is casual, it’s quick and once you’re used to watching it, it begins to look like any other social interaction.” The new book, with photographs by Frans Lanting, will be published in May by the University of California Press. In “Bonobo,” de Waal draws upon his own research as well as that of many other primatologists to sketch a portrait of a species much less familiar to most people than are the other great apes — the gorilla, the orangutan and the so-called common chimpanzee. The bonobo, found in the dense equatorial rain forests of Zaire, was not officially discovered until 1929, long after the other apes had been described in the scientific literature.

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. All of which has relevance for understanding the roots of human nature. De Waal seeks to correct the image of humanity’s ancestors as invariably chimpanzee-like, driven by aggression, hierarchical machinations, hunting, warfare and male dominance. He points out that bonobos are as genetically close to humans as are chimpanzees, and that both are astonishingly similar to mankind, sharing at least 98 percent of humans’ DNA. “The take-home message is, there’s more flexibility in our lineage than we thought,” de Waal said. “Bonobos are just as close to us as are chimpanzees, so we can’t push them aside.”

Indeed, humans appear to possess at least some bonobo-like characteristics, particularly the extracurricular use of sex beyond that needed for reproduction, and perhaps a more robust capacity for cooperation than some die-hard social Darwinists might care to admit. One unusual aspect of bonobo society is the ability of females to form strong alliances with other unrelated females. In most primates, the males leave their birthplaces on reaching maturity as a means of avoiding incest, and so the females that form the social core are knit together by kinship. Among bonobos, females disperse at adolescence, and have to insinuate themselves into a group of strangers. They make friends with sexual overtures, and are particularly solicitous of the resident females.

The constructed sisterhood appears to give females a slight edge over resident males, who, though they may be related to one another, do not tend to act as an organized alliance. For example, the females usually have priority when it comes to eating, and they will stick up for one another should the bigger and more muscular male try to act aggressively. Female alliances may have arisen to counter the threat of infanticide by males, which is quite common in other species, including the chimpanzee, but has never been observed among bonobos.

De Waal said that many men grow indignant when they learn of the bonobo’s social structure. “After one of my talks, a famous German professor jumped up and said, ‘What is wrong with these males?’ ” he recalled. Yet de Waal said the bonobo males might not have reason to rebel. “They seem to be in a perfectly good situation,” he said. “The females have sex with them all the time, and they don’t have to fight over it so much among themselves. I’m not sure they’ve lost anything, except for their dominance.”

Bonobo Sex and Society


lesbian bonobos

by Frans B. M. de Waal

(SCIENTIFIC AMERICAN March 1995  pp. 82-88)

At a juncture in history during which women are seeking equality with men, science arrives with a belated gift to the feminist movement. Male-biased evolutionary scenarios– Man the Hunter, Man the Toolmaker and so on–are being challenged by the discovery that females play a central, perhaps even dominant, role in the social life of one of our nearest relatives. In the past few years many strands of knowledge have come together concerning a relatively unknown ape with an unorthodox repertoire of behavior: the bonobo.

The bonobo is one of the last large mammals to be found by science. The creature was discovered in 1929 in a Belgian colonial museum, far from its lush African habitat. A German anatomist, Ernst Schwarz, was scrutinizing a skull that had been ascribed to a juvenile chimpanzee because of its small size, when he realized that it belonged to an adult. Schwarz declared that he had stumbled on a new subspecies of chimpanzee. But soon the animal was assigned the status of an entirely distinct species within the same genus as the chimpanzee, Pan. The bonobo was officially classified as Pan paniscus, or the diminutive Pan. But I believe a different label might have been selected had the discoverers known then what we know now. The old taxonomic name of the chimpanzee, P. satyrus– which refers to the myth of apes as lustful satyrs–would have been perfect for the bonobo.


A Near Relative

This finding commands attention because the bonobo shares more than 98 percent of our genetic profile, making it as close to a human as, say, a fox is to a dog. The split between the human line of ancestry and the line of the chimpanzee and the bonobo is believed to have occurred a mere eight million years ago. The subsequent divergence of the chimpanzee and the bonobo lines came much later, perhaps prompted by the chimpanzee’s need to adapt to relatively open, dry habitats [see “East Side Story: The Origin of Humankind,” by Yves Coppens; SCIENTIFIC AMERICAN, May 1994]. In contrast, bonobos probably never left the protection of the trees. Their present range lies in humid forests south of the Zaire River, where perhaps fewer than 10,000 bonobos survive. (Given the species’ slow rate of reproduction, the rapid destruction of its tropical habitat and the political instability of central Africa, there is reason for much concern about its future.)


If this evolutionary scenario of ecological continuity is true, the bonobo may have undergone less transformation than either humans or chimpanzees. It could most closely resemble the common ancestor of all three modern species. Indeed, in the 1930s Harold J. Coolidge–the American anatomist who gave the bonobo its eventual taxonomic status–suggested that the animal might be most similar to the primogenitor, since its anatomy is less specialized than is the chimpanzee’s. Bonobo body proportions have been compared with those of the australopithecines, a form of prehuman. When the apes stand or walk upright, they look as if they stepped straight out of an artist’s impression of early hominids.

Not too long ago the savanna baboon was regarded as the best living model of the human ancestor. That primate is adapted to the kinds of ecological conditions that prehumans may have faced after descending from the trees. But in the late 1970s, chimpanzees, which are much more closely related to humans, became the model of choice. Traits that are observed in chimpanzees–including cooperative hunting, food sharing, tool use, power politics and primitive warfare–were absent or not as developed in baboons. In the laboratory the apes have been able to learn sign language and to recognize themselves in a mirror, a sign of self-awareness not yet demonstrated in monkeys.


Enter the bonobo. Despite their common name–the pygmy chimpanzee–bonobos cannot be distinguished from the chimpanzee by size. Adult males of the smallest subspecies of chimpanzee weigh some 43 kilograms (95 pounds) and females 33 kilograms (73 pounds), about the same as bonobos. Although female bonobos are much smaller than the males, they seem to rule.

Graceful Apes

In physique, a bonobo is as different from a chimpanzee as a Concorde is from a Boeing 747. I do not wish to offend any chimpanzees, but bonobos have more style. The bonobo, with its long legs and small head atop narrow shoulders, has a more gracile build than does a chimpanzee. Bonobo lips are reddish in a black face, the ears small and the nostrils almost as wide as a gorilla’s. These primates also have a flatter, more open face with a higher forehead than the chimpanzee’s and–to top it all off–an attractive coiffure with long, fine, black hair neatly parted in the middle. Like chimpanzees, female bonobos nurse and carry around their young for up to five years. By the age of seven the offspring reach adolescence. Wild females give birth for the first time at 13 or 14 years of age, becoming full grown by about 15. A bonobo’s longevity is unknown, but judging by the chimpanzee it may be older than 40 in the wild and close to 60 in captivity.


Fruit is central to the diets of both wild bonobos and chimpanzees. The former supplement with more pith from herbaceous plants, and the latter add meat. Although bonobos do eat invertebrates and occasionally capture and eat small vertebrates, including mammals, their diet seems to contain relatively little animal protein. Unlike chimpanzees, they have not been observed to hunt monkeys. Whereas chimpanzees use a rich array of strategies to obtain foods–from cracking nuts with stone tools to fishing for ants and termites with sticks–tool use in wild bonobos seems undeveloped. (Captive bonobos use tools skillfully.) Apparently as intelligent as chimpanzees, bonobos have, however, a far more sensitive temperament. During World War II bombing of Hellabrun, Germany, the bonobos in a nearby zoo all died of fright from the noise; the chimpanzees were unaffected.

Bonobos are also imaginative in play. I have watched captive bonobos engage in “blindman’s buff.” A bonobo covers her eyes with a banana leaf or an arm or by sticking two fingers in her eyes. Thus handicapped, she stumbles around on a climbing frame, bumping into others or almost falling. She seems to be imposing a rule on herself: “I cannot look until I lose my balance.” Other apes and monkeys also indulge in this game, but I have never seen it performed with such dedication and concentration as by bonobos. Juvenile bonobos are incurably playful and like to make funny faces, sometimes in long solitary pantomimes and at other times while tickling one another. Bonobos are, however, more controlled in expressing their emotions– whether it be joy, sorrow, excitement or anger–than are the extroverted chimpanzees. Male chimpanzees often engage in spectacular charging displays in which they show off their strength: throwing rocks, breaking branches and uprooting small trees in the process. They keep up these noisy performances for many minutes, during which most other members of the group wisely stay out of their way. Male bonobos, on the other hand, usually limit displays to a brief run while dragging a few branches behind them.


Love, Not War





Sex, it turned out, is the key to the social life of the bonobo. The first suggestion that the sexual behavior of bonobos is different had come from observations at European zoos. Wrapping their findings in Latin, primatologists Eduard Tratz and Heinz Heck reported in 1954 that the chimpanzees at Hellabrun mated more canum (like dogs) and bonobos more hominum (like people). In those days, face-to- face copulation was considered uniquely human, a cultural innovation that needed to be taught to preliterate people (hence the term “missionary position”). These early studies, written in German, were ignored by the international scientific establishment. The bonobo’s humanlike sexuality needed to be rediscovered in the 1970s before it became accepted as characteristic of the species.


Another similarity with humans is increased female sexual receptivity. The tumescent phase of the female’s genitals, resulting in a pink swelling that signals willingness to mate, covers a much longer part of estrus in bonobos than in chimpanzees. Instead of a few days out of her cycle, the female bonobo is almost continuously sexually attractive and active.






Female Alliance




On arrival in another community, young bonobo females at Wamba single out one or two senior resident females for special attention, using frequent GG rubbing and grooming to establish a relation. If the residents reciprocate, close associations are set up, and the younger female gradually becomes accepted into the group. After producing her first offspring, the young female’s position becomes more stable and central. Eventually the cycle repeats with younger immigrants, in turn, seeking a good relation with the now established female. Sex thus smooths the migrant’s entrance into the community of females, which is much more close-knit in the bonobo than in the chimpanzee.



Bonobos are unique in that the migratory sex, females, strongly bond with same-sex strangers later in life. In setting up an artificial sisterhood, bonobos can be said to be secondarily bonded. (Kinship bonds are said to be primary.) Although we now know HOW this happens–through the use of sexual contact and grooming–we do not yet know WHY bonobos and chimpanzees differ in this respect. The answer may lie in the different ecological environments of bonobos and chimpanzees–such as the abundance and quality of food in the forest. But it is uncertain if such explanations will suffice. Bonobo society is, however, not only female-centered but also appears to be female-dominated. Bonobo specialists, while long suspecting such a reality, have been reluctant to make the controversial claim. But in 1992, at the 14th Congress of the International Primatological Society in Strasbourg, investigators of both captive and wild bonobos presented data that left little doubt about the issue. Amy R. Parish of the University of California at Davis reported on food competition in identical groups (one adult male and two adult females) of chimpanzees and bonobos at the Stuttgart Zoo. Honey was provided in a “termite hill” from which it could be extracted by dipping sticks into a small hole. As soon as honey was made available, the male chimpanzee would make a charging display through the enclosure and claim everything for himself. Only when his appetite was satisfied would he let the females fish for honey. In the bonobo group, it was the females that approached the honey first. After having engaged in some GG rubbing, they would feed together, taking turns with virtually no competition between them. The male might make as many charging displays as he wanted; the females were not intimidated and ignored the commotion. Observers at the Belgian animal park of Planckendael, which currently has the most naturalistic bonobo colony, reported similar findings. If a male bonobo tried to harass a female, all females would band together to chase him off. Because females appeared more successful in dominating males when they were together than on their own, their close association and frequent genital rubbing may represent an alliance. Females may bond so as to outcompete members of the individually stronger sex.

The fact that they manage to do so not only in captivity is evident from zoologist Takeshi Furuichi’s summary of the relation between the sexes at Wamba, where bonobos are enticed out of the forest with sugarcane. “Males usually appeared at the feeding site first, but they surrendered preferred positions when the females appeared. It seemed that males appeared first not because they were dominant, but because they had to feed before the arrival of females,” Furuichi reported at Strasbourg. Occasionally, the role of sex in relation to food is taken one step further, bringing bonobos very close to humans in their behavior. It has been speculated by anthropologists– including C. Owen Lovejoy of Kent State University and Helen Fisher of Rutgers University–that sex is partially separated from reproduction in our species because it serves to cement mutually profitable relationships between men and women. The human female’s capacity to mate throughout her cycle and her strong sex drive allow her to exchange sex for male commitment and paternal care, thus giving rise to the nuclear family.

This arrangement is thought to be favored by natural selection because it allows women to raise more offspring than they could if they were on their own. Although bonobos clearly do not establish the exclusive heterosexual bonds characteristic of our species, their behavior does fit important elements of this model. A female bonobo shows extended receptivity and uses sex to obtain a male’s favors when–usually because of youth–she is too low in social status to dominate him. At the San Diego Zoo, I observed that if Loretta was in a sexually attractive state, she would not hesitate to approach the adult male, Vernon, if he had food. Presenting herself to Vernon, she would mate with him and make high- pitched food calls while taking over his entire bundle of branches and leaves. When Loretta had no genital swelling, she would wait until Vernon was ready to share. Primatologist Suehisa Kuroda reports similar exchanges at Wamba: “A young female approached a male, who was eating sugarcane. They copulated in short order, whereupon she took one of the two canes held by him and left.” Despite such quid pro quo between the sexes, there are no indications that bonobos form humanlike nuclear families. The burden of raising offspring appears to rest entirely on the female’s shoulders. In fact, nuclear families are probably incompatible with the diverse use of sex found in bonobos. If our ancestors started out with a sex life similar to that of bonobos, the evolution of the family would have required dramatic change. Human family life implies paternal investment, which is unlikely to develop unless males can be reasonably certain that they are caring for their own, not someone else’s, offspring. Bonobo society lacks any such guarantee, but humans protect the integrity of their family units through all kinds of moral restrictions and taboos. Thus, although our species is characterized by an extraordinary interest in sex, there are no societies in which people engage in it at the drop of a hat (or a cardboard box, as the case may be). A sense of shame and a desire for domestic privacy are typical human concepts related to the evolution and cultural bolstering of the family.

Yet no degree of moralizing can make sex disappear from every realm of human life that does not relate to the nuclear family. The bonobo’s behavioral peculiarities may help us understand the role of sex and may have serious implications for models of human society. Just imagine that we had never heard of chimpanzees or baboons and had known bonobos first. We would at present most likely believe that early hominids lived in female- centered societies, in which sex served important social functions and in which warfare was rare or absent. In the end, perhaps the most successful reconstruction of our past will be based not on chimpanzees or even on bonobos but on a three-way comparison of chimpanzees, bonobos and humans.

Social Organization among Various Primates















‘Barefoot Bandit’ Suspect Is Caught in the Bahamas


July 11, 2010


NASSAU, the Bahamas (AP) — The teenager known as the “Barefoot Bandit,” who is suspected of having stolen cars, boats and airplanes to dodge American law enforcement officials, was captured Sunday as he tried to make a water escape. He was then brought here to the capital, handcuffed and shoeless, abruptly ending his two-year life on the lam.

The teenager, Colton Harris-Moore, was arrested before dawn in northern Eleuthera, said Sgt. Chrislyn Skippings, a spokeswoman for the Royal Bahamas Police Force.

Mr. Harris-Moore, 19, kept his head down and ignored questions shouted by reporters. He faces possible extradition to the United States.

Police officers had been searching for the fugitive since he was said to have crash-landed a stolen plane a week ago on nearby Great Abaco Island, where he was blamed for a string of at least seven break-ins.

The authorities caught Mr. Harris-Moore on Harbour Island, a small tourist destination just off mainland Eleuthera, the police commissioner, Ellison E. Greenslade, said at a news conference.

Mr. Harris-Moore was carrying a handgun that he tried to throw away, and shots were fired during a water chase, Commissioner Greenslade said. He did not say who fired the shots.

“It was like something you might see in the movies,” he said.

A spokesman for the United States Embassy in Nassau, Jefferson Dubel, praised the “outstanding efforts” of the Bahamian authorities who captured the teenager.

Mr. Harris-Moore, who has been running from American law enforcement since escaping from a Washington State halfway house in 2008, gained fame and thousands of fans who admired his ability to evade arrest. He is suspected of stealing cars, boats and at least five planes, including the aircraft he was said to have taken in Indiana and flown more than 1,000 miles to the islands off Florida’s coast, despite a lack of formal flight training.

He was dubbed the “Barefoot Bandit” because he was thought to have gone shoeless during some crimes and was once said to have left behind chalk footprints as a calling card.

Reached early Sunday at her home on Camano Island in Washington State, Mr. Harris-Moore’s mother, Pam Kohler, said that she had heard the news about the arrest, but had no comment.