NARRATOR: Within this remote African forest lives a great ape. It's one of our closest living relatives, yet to many, it's a complete stranger. It's the bonobo.
Until quite recently, bonobos were thought to be just smaller versions of chimpanzees. They do resemble chimps, but they're a completely different species.
Where chimpanzees fight and murder, bonobos are peacemakers. And unlike chimps, it's not the bonobo males, but the females, who have the power. Much of bonobo life revolves around one activity, sex. It may even be the reason why they're so peaceful. These animals could give us new insights into our own background, in particular, where we get our gentler side.
But just as we started learning about them, their homeland, the Democratic Republic of the Congo, plunged into civil strife. Beginning in 1994, the fighting raged for almost a decade. These animals were caught in the crossfire and hunted for meat by a starving population.
The peaceable bonobos became casualties of war. Researchers are only now returning to the Congo to see if any survived. Is there still hope for the bonobo or have we lost the chance to get to know this intriguing of our family? The Last Great Ape, up next on NOVA.
Major funding for NOVA is provided by the Howard Hughes Medical Institute, serving society through biomedical research and science education: HHMI.
And by the Corporation for Public Broadcasting, and by contributions to your PBS station by viewers like you. Thank you.
NARRATOR: The tributaries of the great Congo River lead to the only place on Earth that's home to an amazing ape, the bonobo. This has always been a difficult place to travel. Even now, the journey takes many days. As the river snakes into the heart of Africa, it's easy to feel you're going back in time.
These are some of the oldest and richest rainforests in the world. The water doesn't stop at the bank; swamp forest stretches back from the river's edge for over half a mile. It's a tough place to get around, unless you live up in the canopy.
Animals like colobus monkeys can be found throughout this region. But it's only within a single bend of the Congo River that bonobos are found. This part of the forest is like a time capsule; bonobos may have existed here in much the same way for 2,000,000 years.
These deeply intelligent apes seem very relaxed. They take afternoon naps, are highly social, and develop lifelong friendships. Mothers nurse their babies for about five years. Such an extended childhood is rare in the animal kingdom, but for young bonobos, it provides a crucial time to learn about the world.
It's hardly surprising these creatures strike a chord. We humans share a common ancestor with both bonobos and chimpanzees. Between five and seven million years ago, our ancestors branched off from the apes. Humans still share over 98 percent of our DNA with both bonobos and chimps, who split into separate species themselves about 2,000,000 years ago.
But only bonobos continued to live just in these lush forests where they first evolved. Because their home in the jungle is so remote, scientists weren't able to study them in the wild until the mid-1970s.
In the rainforests of the Congo, two groups of researchers set up study camps in Lomako and Wamba. Even then, the Congo and many of its neighboring countries, like Rwanda and Angola, were politically unstable. This is a dangerous place to study animals.
Frances White is one of the few scientists who risked observing them in the forest. Along with a small group of researchers, she pioneered the work on bonobos at the site in Lomako. Her work takes persistence. Bonobos spend far more time in the canopy, so finding them in this forest is notoriously difficult.
FRANCES WHITE (University of Oregon): We could have runs of days without finding them. If they're up in the trees, lying still, you could walk right by them and you don't know they're there. There would be times we couldn't find them even if they weren't trying to hide from us.
NARRATOR: It took years of constant observation to gain the trust of these shy animals. When studies began, researchers estimated there were fewer than 55,000 bonobos in existence. Hidden away in this distant jungle, these endangered apes are still largely unknown to the rest of the world. Unlocking their secrets has proved slow and arduous.
Bonobos have also been overlooked because they have been studied far less than their better-known cousins, the chimpanzees. Chimps are easier to study because they live across Africa in greater numbers. They also tend to steal the limelight, in part because of their excitable and violent nature.
Chimp society is defined by power. Male chimps spend their lives making and breaking alliances. At their most aggressive, they band together, crossing into adjoining territories to hunt down and kill neighboring groups of chimps. A conflict can be bloody and brutal. But when different bonobo troops meet, the outcome is often not war but peace.
In a second study area in Wamba Forest, a team led by Japanese researchers watched bonobos over a 20-year period. They recorded what happens when different groups of bonobos meet.
TAKESHI FURUICHI (Meiji Gakuin University): We have not observed any case of inter-group killing. So, in Wamba, there are five or six groups of bonobos and then they sometimes encounters. And the males become very excited and they form a group, form a front rank. This side is this group and the other side is the other group, and they continue displaying, shaking branch and something like that.
NARRATOR: The male bonobos posture at each other from either side of the boundary line. But the females take a very different course of action. They all get together.
TAKESHI FURUICHI: So females start merging, and they started grooming with each other, and then eat with each other. And, finally, males give up. In most extreme case, two completely different groups merged completely, and then they moved together for a week or more.
NARRATOR: While chimps may practice warfare and aggression, bonobos are more sociable and inclined to get along with their neighbors. Together, the behavior of these two great apes appears to reflect both sides of human nature.
FRANS DE WAAL (Emory University): If you look at human society, it's, of course, very easy to compare our warfare and territoriality with the chimpanzees. But that's only one side of what we do. We also trade, we intermarry, we allow each other to travel through our territory to some other place. There's an enormous amount of co-operation. And actually, among hunter gatherers, peace is much more the common activity, 90 percent of the time, and war is only a small part of the time. And about the peaceful relations, chimps cannot tell us anything, because chimps have only different degrees of hostility between communities, whereas bonobos do tell us something. They do tell us about the possibility of having peaceful relationships.
NARRATOR: Simply watching bonobos reveals how unlike chimps they are, especially in ways we consider most human.
FRANS DE WAAL: I met them the first time and I thought immediately, "They're totally different." The sense that you get, looking them in the eyes, is that they are more sensitive, more sensual. Not necessarily more intelligent, but there's a high emotional awareness, so to speak, of each other and also of people who look at them.
NARRATOR: And there are other surprises. Scientists had assumed that all great apes fit into hierarchies dominated by males, like the chimps.
RICHARD WRANGHAM (Harvard University): Chimpanzee society is horridly patriarchal, horridly brutal, in many ways, from the female point of view. In order to be an adult male chimpanzee, you have to be able to dominate all of the females. So that's rough from the female's point of view. They regularly get beaten up in horrid ways.
NARRATOR: But female bonobos aren't dominated by males; female bonobos are in charge. This was so unexpected that when researchers first reported it, they were met with resistance and disbelief.
FRANCES WHITE: I remember I got comments back saying, "No, this is totally wrong, the males are all off in groups. They're just doing it when she's not looking." And I kept being told I should look harder to find these all-male groups because they were there and I was just not seeing them.
NARRATOR: But bonobo society is matriarchal, difficult as it was for some scientists to accept.
FRANS DE WAAL: When something doesn't fit your thinking, the best way to deal with it is to shove it out of the window and ignore it. And that's what the scientific community did.
NARRATOR: But at mealtime, it's unmistakable: sisterhood is power. Although males and females search for food together, females decide how it is shared out.
A fallen bolingo fruit is a favorite, but it's the females who get to feed first. Male chimps wouldn't tolerate it, but male bonobos have to wait their turn.
The females often share food with each other. It's a crucial way of strengthening their bonds. The males might want to muscle in, but if the females stand united, the males remain under their collective thumb.
Individually, a male bonobo is stronger than a female, but shows of strength remain just that. Mostly they're ignored. Male bonobos are also kept in check because they don't rely on each other for support. They lack the powerful alliances that give male chimps the upper hand. A male bonobo remains by his mother's side for much of his life.
TAKESHI FURUICHI: Sons of very high ranking females get a very high social status. They are always depending on their mother. Even if they are fully grown adult males, they are still following their old mother and ask for her help, until their mother dies. And then, when their mother dies, their social status will go down, because they have no supporters any more.
NARRATOR: Sometimes this happens at a very young age. When this bonobo was three years old his mother died. Since then, he's had no influence within the group. The other youngsters will play with him, but the play sometimes gets rough. When things seem to be getting out of hand, a mother bonobo intervenes and winds up biting the orphan on the hand. When she disappears, the young bonobo remains behind, studying the orphan's injured hand.
The orphan is isolated and injured. But eventually, other youngsters will come to see what the matter is. They appear curious, even concerned. Though chimps are known to demonstrate this behavior, some researchers believe that bonobos are the most caring of all the great apes, except for us. Perhaps here is a glimpse of a behavior rooted in our shared past.
Bonobos aren't just concerned with each other. They are known to help other species, too.
FRANS DE WAAL: There was a bonobo at a zoo in England who found a little bird, a starling, that had hit the window at the zoo, and the starling was stunned. And she picked it up, she took it in her hand, and she climbed to the highest point of her enclosure, the highest tree. And she wrapped her feet across the tree, so that she had her hands free, and she unfolded the bird like this, like a little toy airplane, she sent it out. Which I think is amazing, because it means that, of course not something she could do to a bonobo, that would be stupid to do that, but for a bird that seems to be the appropriate help.
NARRATOR: For a long time scientists argued that such traits like kindness and empathy belong to people alone. But observing these animals and other great apes has led to a new interpretation.
While bonobos have a generally peaceful temperament, they do have disputes and moments of aggression. But they avoid violence through a very natural method—though it may be shocking to us—sex on a very frequent basis. Most animals, even chimps, have only a few days each month when females are sexually active. But bonobo females have sex through much of their cycle, even when there's no chance of getting pregnant.
Like humans, bonobo sex isn't just about having babies.
What is different is that sex has spilled over into most areas of bonobo life.
FRANS DE WAAL: In the bonobos, sex is really... permeates everything they do. It is a greeting, it is a reconciliation, it is a mother-child bonding thing, it is a female bonding thing. And so, sex has a lot of social functions that it has taken on. And that's also why it is used in all possible combinations, not just male to female, because sex has a wider social function.
NARRATOR: A bit like a handshake or a hug, it lasts only a few seconds.
FRANS DE WAAL: The sex of the bonobo is very casual, very quick—and they do it, not the whole day, which people sometimes think, but that's the human perception—but eight, nine, ten seconds. It's not so much.
NARRATOR: But these brief sexual contacts have an enormous impact on the overall calmness of bonobo life. Intimacy makes it hard to stay angry. Bonobo disputes might begin aggressively, but sex can smooth tensions, even in mid-charge.
The gentle nature of bonobo sex contrasts sharply with that of chimps, and it may have evolved as a protective measure. In chimp society, where sex is mainly for reproduction, males compete so aggressively to breed that they've been known to kill each other's offspring. Once a mother loses a nursing baby, she becomes a potential mate.
But bonobos aren't known to commit infanticide, perhaps because fatherhood is nearly impossible to determine. Frequent sex with multiple partners is the norm for both males and females.
FRANS DE WAAL: Since females have sex with all the males, basically, and have sex frequently, there is no male in the group who knows whose female's offspring he has. If males cannot tell which infant is his or not his, he has to stop being infanticidal, otherwise, he may, on occasion, kill his own offspring, which is certainly not to his advantage.
NARRATOR: So what caused bonobos to evolve this more peaceful coexistence which chimps did not? The difference may be a result of their food-rich habitat.
RICHARD WRANGHAM: The bonobos live in an environment where there is more food available on the ground. And there are chimpanzees that live in similar forests, but wherever those forests are occupied by chimpanzees, they're also occupied by gorillas. And gorillas eat those herbs on the ground.
NARRATOR: Chimps have less food available, and what food there is, dominant males get to first.
RICHARD WRANGHAM: The males have finished all the food by the time the mothers arrive. So the mothers disperse away from each other and away from the males. That means they can't have much opportunity to form bonds with each other.
NARRATOR: So female chimps spend much of their time alone, searching for food and vulnerable to male aggression.
But the bonobos environment provides easier access to food, allowing females to eat together and bond, which gives them power. Bonobos, with their matriarchies, their cooperation and their tolerance towards different communities, appear to turn long-cherished ideas about apes upside down.
They also raise fascinating questions about our own background.
FRANS DE WAAL: Imagine that we didn't know the chimpanzee, and all we knew was these bonobos who have sex all the time and were peaceful and female-dominated. And people would say, "This is the only close relative that we have." I think we would have totally different theories about ourselves and our background. But of course, it didn't happen that way. We actually ended up knowing the chimpanzee first.
NARRATOR: Since the mid-1970s, scientists made great progress in understanding the bonobo. But by 1994, it became increasingly difficult to study them. Genocide in neighboring Rwanda de-stabilized the whole of Central Africa. The fighting spilled over into the Congo, as extremist militias and refugees fled across the border.
The rainforests around Lomako and Wamba still sheltered the bonobos and other wildlife, but they were becoming extremely dangerous places to live and work.
FRANCES WHITE: It was very hard to supply and buy things to come into the field. There was nothing in shops; the shops were just completely empty. It was very hard to travel around. It was very hard to buy fuel for our vehicle. So it was becoming very difficult to work.
NARRATOR: Over the next few years, the violence and political upheaval in the Congo escalated. Reeling from tensions with Rwanda, the Congo's government itself was overthrown. Factions from neighboring countries lined up behind Congo rebels and government forces in a struggle for power. In 1998, the country plunged into a full-blown civil war and the violence reached far into the jungle. Even bonobo researchers came under suspicion.
JEF DUPAIN (African Wildlife Foundation): Soldiers came to our campsite to arrest us, because they...there was a general belief that we were spies for the enemy. And so they showed up, about 10 of them. They showed up at the campsite, they arrested us. They found, of course, that we were walking in the forest with walkie talkies, we had a cell phone, we had radiophone. So that was enough proof. But these soldiers said...I mean, in Basankusu everybody was...it was a bit crazy, the idea that while war was going on, some, some naive white people are running after bonobos in the forest. I mean, this normally you don't do. If there are diamonds or gold, yes. So they were coming to look for the diamonds first. When they didn't find the diamonds, they decided that then we are spies.
NARRATOR: The scientists were rounded up and forced out, lucky to escape with their lives. More than 20 years' worth of observations, of valuable records of individual bonobo lives came to an end.
There was chaos, as millions of people were displaced from their homes. By 2001, over 3,000,000 people had died, most of them from disease and starvation.
In desperation, many people turned to the forest for food. Weapons flooded into the country and all animals, bonobos included, were threatened.
Bonobos call loudly to each other when they bed down for the night, and this made them easy targets. Their forced refuge was under siege.
Because the researchers could not return, no one knew what was happening to the bonobos while the war dragged on.
One scientist, Jef Dupain, did remain in the Congo, though he could not venture into his old study area, the Lomako Forest. He tried to keep tabs on the bonobos by organizing a study to record what kind of meat was being brought to the market.
JEF DUPAIN: We did a study in the market here in Basankusu and we...every day the market here was visited by local assistants and recorded for 12 months: about 12,000 carcasses of meat, here at the market at Basankusu, 35 percent of which came from Lomako Forest, which indicates the importance of Lomako Forest for animal proteins here in Basankusu.
NARRATOR: In a starving country, the forest animals are destined for the pot.
JEF DUPAIN: Many people eat bushmeat, including monkeys, and bonobo is a normal part of their diet. To prepare it in some palm oil with some onion, some potato, some tomato and some pimento—whether it is a duck, a forest pig, or a bonobo—most of the time it is mostly prepared in the same way.
MAN: Meat is meat.
JEF DUPAIN: Meat is meat.
NARRATOR: But the meat was not just for starving families. As the war progressed, an army of professional poachers illegally took more and more animals from the forest.
There was no one to stop the slaughter, except for these men. The guards at Salonga National Park had 2,000 miles of rivers to patrol, but they had no training. They didn't even have an outboard motor. They were completely outgunned.
BOKUNGA YOKA (Salonga National Park Warden): There were 10 of them and only three of us. They shot my arm. Now it doesn't work.
ROGER MOONGA (Salonga National Park Warden): The poachers shot me through the lung. I spent the night in the water before my friends found me. I thought I was going to die.
NARRATOR: During the war, 250 Congolese park wardens lost their lives.
The great Congo River and its tributaries snake a thousand miles from the deepest jungle to the heart of the capital, Kinshasa. Boats carried shipments of bushmeat for a city flooded with starving refugees. But they had another cargo, live animals for the pet trade.
For each baby bonobo taken, several bonobos had probably been slaughtered. This baby has been rescued from the market and will be taken to an orphanage in Kinshasa. Most babies are terrified and malnourished when they arrive. A team of surrogate mothers gives them food, medicine, and the love and attention they'd normally get from their own mothers.
BONOBO ORPHANAGE WARDEN: La bananne, c'est bon, c'est good. Oui.
NARRATOR: During the war the number of babies arriving at the orphanage spiraled. There were reports that bonobos in the wild were facing extinction, that soon these refuges would be the only place that bonobos could be found.
But the forests remained too dangerous to survey until 2003, when an uneasy peace returned to parts of the Congo. It brought relief for millions of people who had endured terrifying times. Now it was possible to find out what lay behind the headlines.
It did not look good.
JEF DUPAIN: We just went to look what the situation was on bonobos in our former study site. And at that moment the results were really discouraging. We spent a number of days in the forest, didn't find traces of bonobos. Overall, at that moment, we had quite a pessimistic feeling on the bonobos.
NARRATOR: The forests seemed empty. Bonobos have always been difficult to find, but now no one knew if they were there at all.
Scientists from around the world were starting to return. Frances White has not been able to visit her study site since before the war. This is her first journey back. She's returning to see whether there's any chance of resuming her work. What, if anything, will she find?
This once familiar river trip is now a journey into the unknown.
FRANCES WHITE: Once we get out of the boat and head into the forest, that's when we'll really know whether there's been a big change. If we walk into the study site, do we see lots of monkeys? Do we see all the species of monkeys we are used to seeing? And how many groups are there in the study area? And then, of course, the big question is how the bonobos are doing.
NARRATOR: Frances is also worried about the fate of her local tracker, Papa Bosco, whose family remained in the area throughout the terrible years of the war.
The first signs are hopeful, as Frances arrives at the small community which supported her before the war. Bosco is alive.
Frances has brought gifts of salt, a precious commodity that was impossible to get here during the war. The villagers have suffered terribly.
PAPA BOSCO (Forest Tracker): I ran into the forest with my family to hide from the soldiers who were hunting me. If they had found me, I would be dead now. It makes me cry to remember. Many children died because they could not survive in the forest.
NARRATOR: Now the villagers hope life can return to normal. A new bonobo study would bring sorely needed cash to this community, but are there any animals left? Frances heads straight into the forest.
FRANCES WHITE: So when you see broken branches, especially large branches, start checking it out for a nest there.
NARRATOR: They are looking for any signs that bonobos are still using the area.
FRANCES WHITE: Now, there's something on there. Hang on. I like finding fingerprints, when I can find them, or knuckle prints. On hot days like this, they'll come down to the stream and make knuckle prints.
NARRATOR: There are no knuckle prints, but there is a good sign further down the trail.
FRANCES WHITE: It's a plant that the bonobos have eaten. And they open it up to get the pith out from the middle, so that you can eat the inside, as a sort of, like a celery kind of thing. But, it's been opened today, and it's only the bonobos that eat this on the ground, so there was at least one bonobo here today. They're in this area somewhere, which is very exciting.
We just saw that one sign, the buncombe vine that had just been eaten. That was very fresh. It had not gone dark at all, and, to my mind, that could mean that an animal had just eaten it, only within an hour of when we walked past. And we heard that noise that could have been a bonobo, but people were talking at the time and it was hard to tell. So it's possible that was an animal that we heard, that it walked through on the ground, pulling buncombe as it went, and it's still very close to us, here, somewhere.
NARRATOR: But with the light fading, they are forced to return to the camp. Next morning their hopes are raised again, when they find some old sleeping nests in the canopy.
FRANCES WHITE: ...two, three, four, five. Five and it's...plus the ones there. How old are these? That's, that's old. And that's, that's old, but that looks new.
NARRATOR: A new nest is the most compelling evidence so far that bonobos are somewhere around.
FRANCES WHITE: Okay, got it, I got it. That's a fairly new too. One old one, and the other, six...six plus one, that's good. So, potentially, nine; we've up to nine, which means there's nine nests. Well, we've more than nine, but nine were built on about the same day, so, potentially, it's a group of nine.
NARRATOR: They decide to go home and then stake out this area early the next day.
The following morning, before dawn, they trace back to where they found the group of nests.
FRANCES WHITE: A part of the nest. This one is up. Up here, straight up through there...
CAMERAMAN: I've got it.
FRANCES WHITE: Got it? Oh, that's incredible. Come back here. Oh, that's incredible! Oh, it's fantastic, just fantastic to see how they are not reacting to us. They know we are here. They're looking down, and they're not worried. Oh, that's wonderful! Really wonderful! Oh, it's fantastic!
NARRATOR: But there's even better news.
FRANCES WHITE: It's really exciting. There's a mother, a female with an infant, up here, a little baby.
NARRATOR: The bonobos have survived, and they're thriving.
FRANCES WHITE: I thought there was a very good chance that there would be no bonobos here at all. And it was, basically, thinking of it, that it was the end of an era, an era, end of possibility of understanding them anymore. That it would be just one of those puzzles that people would never really work out, in terms of what was really going on with bonobos, because they'd be gone. And it would be really, really sad. And it was so great to come here and to see them, and not only to see them, but to find females with infants. And we saw a pregnant female, and it's...Clearly the groups are doing great. And they are reproducing, and they are having babies.
NARRATOR: Frances's study site, Lomako has fared better than some. One third of the bonobos around the study site Wamba were killed during the war. Over the whole country there may be fewer than 30,000 left.
A picture has slowly been emerging of how the bonobos may have survived. The theory is they visited their traditional feeding grounds only when soldiers and poachers had left the area. The rest of the time, they stayed invisible.
FRANCES WHITE: Because they are so intelligent, they would hide from people that were looking for them. So they just wouldn't be found, even though they're still there.
NARRATOR: Bonobos are clever primates. They have proven themselves capable of change. It's long been known that bonobos, like chimps, are highly intelligent apes. But intelligence is only one trait they share with us.
Recent developments in genetics suggest that we might have more in common with bonobos than we ever thought.
FRANS DE WAAL: They have found that a particular piece of DNA that is involved in affiliation and bonding is present in humans. It's present in bonobos, but it's absent in the chimpanzee. So we share a particular piece of DNA with the bonobo that the chimp doesn't have, which may indicate that some of our social behavior is more similar to the last common ancestor and that we share that with the bonobo.
NARRATOR: Bonobos may reveal further surprises, but only if they're able to survive. For now, Jef Dupain has put his bonobo research on hold. Instead he is trying to encourage local people to rebuild their farms in order to reduce dependency on bushmeat.
JEF DUPAIN: One of the main reasons why people are focusing more and more on bushmeat in this area, for trade and self-consumption, is the fact that they have no alternatives. So by reactivating agriculture, we hope, one: to increase supply of subsistence crops; two: to increase livelihoods of families so that they don't have to get into the forest again to get some basic meats.
NARRATOR: Research at Wamba Forest has started up again, and Frances White continues to work towards re-establishing the site at Lomako. Her goal is to find the specific animals that she identified and tracked before the war.
But in the Congo, simmering tensions could threaten to boil over. Without long-term security, the jungles will remain a place to hunt animals rather than study them. But if research can be re-established and the bonobo protected, who knows what revelations they'll offer.
The bonobos' world is a kind of time machine, an important rear-window on our own history. Bonobos can provide us with insight, not only into the evolution of intelligence, but into our own social nature as well.
Now that they've managed to survive the war, we have the chance to discover more about our peace-loving cousins, and possibly find out more about ourselves.
On NOVA's Last Great Ape Web site, meet an expressive bonobo named Kanzi, see a slideshow of bonobo gestures, explore a primate family tree and more. Find it on PBS.org.
Educators and educational institutions can order this or other NOVA programs, for $19.95 plus shipping and handling. Call WGBH Boston Video at 1-800-255-9424.
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Major funding for NOVA is provided by the Howard Hughes Medical Institute, serving society through biomedical research and science education: HHMI.
And by the Corporation for Public Broadcasting, and by contributions to your PBS station by viewers like you. Thank you.
The Last Great Ape
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