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National Geographic: The New Chimpanzees (1995)
"THE NEW CHIMPANZEES"
Chimpanzees. So like us, we are both captivated and repelled. As we move through the looking glass into their world we are transformed. Chimpanzees, our forest-dwelling counterparts, unite us with the rest of nature. Eerily, they recall our prehistoric ancestors. Their social life reflects ours, too. With paramilitary patrols political struggles for power and gain even outright wars. The tender affection they show for one another their gestures and expressions all seem strangely familiar. Their invention of tools forced us to redefine what sets humanity apart from the beast. And now we discover that chimps developed not only tools, but entire cultures which they pass on to their young. Even medicine seems within their grasp And when stalked by death, they seem to feel a sorrow we can share. With a shiver of recognition, we glimpse the mind of the chimp and realize we are not alone. Come with us on a voyage of discovery, a journey into our collective past. We retrace our steps back into the forest of Africa, the ancient homeland our species abandoned some six million years ago. We left behind, then, our closest relation the one being on this planet most like us. For there is a mind in the forest, a mind very much like our own, And it lights the eyes of the chimp. Chimpanzees share more than 97% of our genes. And it shows. The invention and use of tools was supposed to set us apart from the other animals. But this chimpanzee is "fishing" for safari ants with a wand specially selected and pruned for the task. Chimps make and use many tools skills passed on from mother to child part of their cultural heritage. "Ant-fishing" requires real expertise. Safari ants are a rich food source, but they pack a vicious bite. With one fell swoop, they're down. At eight years of age, her daughter still has much to learn. But someday she will master this technique, not just by trial and error but by watching her mother at work. For the past 35 years, scientists have been watching and learning from her mother, as well. She was an infant herself when she met her first human being, who named her Fifi. That human was Jane Goodall. Jane came to know Fifi, her mother Flo and her entire family quite intimately Goodall was the first human to be accepted by wild chimpanzees. What she discovered revolutionized our concept of chimps and of ourselves. All across Africa, others have followed Goodall's lead. A second species of chimpanzee is studied by Takayoshi Kano. Called bonobos, they're famous for their human like appearance, and the way they substitute sex for violence unlike the more aggressive chimp studied by Goodall and Christophe Boesch. Boesch has unveiled hunting strategies and elaborate tool use among rainforest Chimps leading him to suggest these things might have evolved before our forbears left the forest. And Richard Wrangham believes he may even have discovered Chimps practicing a primitive kind of medicine. The new research takes us ever further into the chimp's world, giving us a new perspective on our shared legacy. Chimpanzees and humans sprang from the same primate stock. Our paths diverged only some six million years ago, with our human forbears moving onto the plains leaving the forest to the chimpanzees. But shared characteristics are written deep in both our primate souls. Chimps, too, are capable of creating distinct cultures. Various "nations" of chimps cling to life across the African landscape. Chimpanzees once thrived throughout the forests of equatorial Africa, while bonobos were restricted to the Congo basin. Today, both species survive in isolated fragments, and are studied at a handful of sites. Gombe, on the shore of Lake Tanganyika in Tanzania, was where Jane Goodall began her study 35 years ago. Fifi is the only chimp still alive from that time with six surviving offspring. Freud, her eldest, is now the dominant male in her group, while her younger son, Frodo, is the largest chimp at Gombe and working his way up the male hierarchy. Freud now leads the tightly bonded party of males that form the core of the group. Male chimps stay in the group of their birth, and cooperate when there is common cause. Every week or so, the males form a paramilitary patrol to defend and test the borders of their territory. In single file and total silence, they follow their leader in search of trespassing neighbors. Hair standing on end, they listen for the voices of their foes. Each community of male chimps jealously guard their territory and the females in residence. A stranger turns and flees. Though groups of males rarely engage in battle, an individual caught by a border patrol is at serious risk. In the 1970's, Jane Goodall described a harrowing chain of events. Her study group split in two, and over the course of four years, the males of one group systematically hunted down and brutally killed every adult in the other group chilling evidence that warfare is a painful legacy from our primate forbears. Gombe's steep slopes the stage for all this high drama tumble from open grassland to riverene forest, from the top of the Great Rift to the blue basin of Tanganyika. Today, a new generation climbs the path blazed by Jane Goodall. Charlotte Uhlenbroek is studying pant hoots, the long range calls of chimps. She follows one male all day, recording the precise time and circumstances of any pant hoot he makes Her Tanzanian associate, Issa Salala, follows another male and does the same At the end of the day, they will compare their notes, to see whether they've witnessed two sides of a conversation, and to try and decipher its meaning. The pant hoots are certainly conveying some meaning. Um, what, what I'm trying to find out is exactly how specific are the meanings of these different calls. I mean, um, does a particular pant-hoot convey something about a food source? Does it say, Come here boys? Does it say I'll meet you up in the next valley? Or are they directed at family members at allies, at friends? Or are they just, generally, Anyone that can hear me, this is my message? We haven't got our ears tuned in. I mean, it's like different cultures very often, it's difficult to hear a slightly different, uh, pronunciation. So, certainly, we're not hearing all the difference out of these. Sometimes, there's still just a cacophony of screams out there and you very hard push to pull them apart; but, I'm sure the chimps can, I'm sure they, they know exactly what's going on. Sometimes words won't suffice. Males perform displays dramatic performances designed to establish their dominance and intimidate rivals. Fearless, Frodo sometimes uses the human researchers to enhance his displays. Even Charlotte has fallen prey. He'll give me a whack. He'll just, just kind of add a little flourish, by incorporating me, but it's not directed at me. He, if he wants to hurt somebody, he could have done it. Females and their young are dominated by this threat of force. But when the fruit crop is ample, everyone feasts. A mother's care is the primary influence on a young chimp's life. Orphans find life hard. Mel was orphaned at the tender age of three. Only the generosity of others has allowed him to survive for six more years. Still, he seems to miss the affection he would have known within his mother's arms something this little baby seems to understand. A temporary respite from a life of loneliness. Beyond the bond between mother and child, political relationships are the life's blood of chimp society. Even while relaxing, chimps are jockeying for status. Grooming is, quite literally, currying favor. Alliances become apparent by observing who grooms whom. Dominant animals and their allies get the best pickings. Food is a precious commodity. They often compress fruit into a pulpy "wodge," something like a tobacco chaw, to extract every last drop of juice. But the calls of colobus monkeys whet another appetite not so easily satisfied. When a monkey troop is spotted nearby, the most avid hunter recruits other males to join forces in a hunting party Red colobus monkeys nervously watch the gathering of bodies below. Craig Stanford studies the relationship between colobus and chimps. He hopes to shed light on the origins of human hunting. We know that, at some point early in human evolution, meat became an important part of the diet. We don't understand exactly how that happened was it scavenging meat or hunting meat Well, we know that the earliest stage of human evolution happened in a habitat just like this. East African woodland that's got open areas onto which our ancestors eventually moved and adapted to. So, to be able to study hunting here is the best way to give us some kind of window onto the earliest origins of meat eating in our ancestors, four or more million years ago. Frodo is the best of the Gombe hunters He's 17 years old and yet he's killed in the last three years. It's really quite an incredible animal and a great hunter. That was Frodo. All the hunters, including Frodo, will try to catch a monkey for himself By joining forces, the chimps hope to strand some monkeys in an isolated treetop, with no route of escape except into the clutches of a chimp. Although we see elements of cooperation at Gombe, what we thing we're seeing mainly is individual, selfish behavior by male hunters, done within a communal setting. It's a little bit like a baseball game in that baseball is a communal game in which individual players are doing their piece and in the end, the end result is going to be success or a failure. The more hunters there are, the greater the odds of success and, yet, each individual hunter is performing selfishly. As the chimps climb up, the colobus retreat to the highest branches too slender to bear a chimp's weight. The male colobus stand their ground against chimps up to four times their size. They will even take the offensive momentarily driving the chimps back. Holding his tail out of the chimp's reach, this male buys precious time for the escape of the females and young. Excited by the cries of hunter and prey, females appear below. Eighty feet above the ground, Frodo displays his daring technique. But this time, he misses. With chimps climbing everywhere, one monkey leaps into the arms of death. Even a rear attack by the defending colobus cannot save him. The young hunter displays with his kill, but his triumph is short liver. Freud simply confiscates the carcass. Freud settles down to share with his allies. Meat is a valuable currency , a payment for favors. Females come begging for a taste. The orphan, Mel, searches for scraps but he's soon sent packing. Frodo, frustrated and hungry, tries to muscle his way to a place at the table. But Freud will have none of it leaving Frodo to rage. His friends rush in to placate him to little effect. With up to 11 males hunting together, multiple kills are common at Gombe. As many as seven monkeys have been taken on a single hunt. Chimps like a little salad with their entree. They often eat leaves when they eat meat, sometimes eating kinds they never touch otherwise. On average, the Gombe chimps consume in their range each year. A taste for meat begins early. The free for all approach to hunting works well in Gombe's low and relatively open woodland. Catching monkeys high in the treetops requires a different strategy elsewhere Christophe Boesch studies chimps in the Tai forest of the Cote d'Ivoire prime African rainforest. Most chimps live in green and shadowy depths like these. The forest canopy an interwoven web floats over a hundred feet above its reflection in tea colored pools below. Following his chimps, he's discovered that they're capable of an extraordinary level of cooperation. I mean, the chimps of the Tai forest or the tropical rainforest. The canopy layer is continuous, the biggest mammal they hunt, the red colobus, they are about a third the weight of the chimps, what means that when colobus sit on a thin branch, the chimps can't go there, if he go there, he fall down on the ground. So, there is a big problem, they have to use, solve it and the only way to solve it here is by hunting in group. So that a chimp will drive the prey away in a given direction, so that the colobus are constantly moving in this direction, and the driver is really just pushing them in a direction, he's not trying to capture them, that is, he's not running, you see that he's just walking in a constant direction. This gives them the constant direction of flight, where the chimps on the ground can then organize them and, if they see that the group splits too much in different directions, you would have blockers, individuals that come up in specific trees where colobus might escape, sort of keep them in constant direction. And so that, gives them the possibility for them to make the kind of a trap. So that, by having a driver behind, some blockers on the side, they just need somebody actually to come in front of them, ahead of the movement, and to then close the trap, if you want. Only the most experienced hunters play this role. They have to race ahead then climb almost a hundred feet above the canopy into the crowns of the tallest trees to ambush their prey. And when they are successful it's incredible because you can have suddenly all the forest is screaming. All the chimps know there have been a capture. The chimps have made a capture call, everybody knows 'meat' that meat is so rare, it's so difficult to acquire and it's only because, uh, adult males have worked together that there is meat, so it's something very special for all group members and there is a huge excitement with that. It's really a, a team work and it works only if the team wants to work and the team doesn't see each other, it's too dense in this forest. So, they are always anticipating that the other one will come and often they don't see if they really did their job and it works only if everybody does their job. This kind of work, on the long run, only if meat is shared according to the work these hunters have been doing You see, alpha male is not the best hunter or is not hunting and he doesn't get meat. You have now an alpha male who's fresh in this position, that is young and he's not always hunting and he can really be there displaying for minutes and not get a tiny piece nothing at all. This division of the spoils based on right rather than might reveals a different division of power. Females, who are allies of the hunters also gain access to the carcass bringing their infants closer to the meat than the blustering alpha male. If this complex division of labor and food seems almost human, so does the chimp's love of play. An infant chimp may seem secure within the bosom of his group, but this is not always true. A male has stolen a baby chimp from its frantic mother, who follows in desperate pursuit. In the Mahale Mountains, south of Gombe, researchers have recorded this terrible event not once but seven times and are at a loss to explain it. The alpha male is now in possession of the screaming infant. He actually beats back the mother with her own baby. Both mother and baby are members of this male's group, and the infant was presumably sired by one of the group's members. Males have been known to kill babies sired by outsiders, but this kidnapper could very well be the baby's father. The infant is killed by a savage bite to the face. Group members share in the macabre feast just as if it were a monkey. Infanticide and cannibalism dark reflections of our common legacy. But the mirror of our primal past reflects light amidst the dark. Aggressive impulses may be rooted in our distant ancestry, but so is our capacity for peaceful coexistence. It is in Africa's dark heart the Congo basin that we find a gentler tributary of our primate legacy. Takayoshi Kano has led the research here in Wamba, Zaire, for the past 22 years. He comes here in search of the second, little known species of chimpanzee. Sugarcane is a sweet lure used to call down the elusive bonobo. Dr. Kano, and his associate Chie Hashimoto, have discovered that bonobos are quite distinct from the chimps studied by Goodall and Boesch. At first glance they are different. Although they've been called pygmy chimps, they're not smaller, just more slightly built. Hunted elsewhere in Zaire, they're safe here but wary still. The sugarcane buffet proves irresistible. At ease on two legs, as well as on four, they simply rise up and walk so their hands are free to carry the cane. Eerily, their long, shapely limbs and upright gait recall our own prehistoric forbears. And their natural two-legged gait is only the first surprise they have in store for us. An impressively stern female enters and snaps a young sapling. Once she picks herself up, she does something entirely surprising for a female chimp. She displays! And the males give her sway. For this is the confident stride of the group's leader, its alpha female, whom Kano has named Haru. Females play a very different role in bonobo society than they do among chimps. The reins of power are shared equally between male and female held by a strongly bonded group of high ranking mothers and their adult sons. The son of a dominant female can take great liberties. High-ranking females cooperate to dominate adult males and support their sons in social conflicts. Though tough with other adults, bonobo mothers almost never discipline their babies even when they steal the food right our of their mouths. Haku, an 11 year old adolescent male, has lost the loving attention of his mother. As an orphan, he has been forced out, to the very fringes of his own community. He's old enough now to begin to make his mark but, without a mother's help, his chance of success is nil. Males stay with their mothers for their entire lives, and rely upon their backing. With no mother to back him up, Haku must be wary of Ten, the alpha male. Ten was just about Haku's age when he first rose to power. Lately, Haku has begun trying to assert himself. But Ten had an advantage. His mother was the alpha female before Haru, and he rose to power on her apron strings. He will not tolerate any display from this "motherless child." Haku has spirit but to no avail. Ten's annoyance with this upstart is soothed by one of the other high ranking males in a surprising way. Instead of fighting, bonobos use sex to defuse aggression in this genuine "make love, not war" society. Bonobos have largely divorced sex from its reproductive role. Sex is used by all bonobos, regardless of gender or age, to form bonds and mitigate tension. So Haku is not likely to suffer physical harm. But without family backing, his bid for status is probably doomed. Adolescent females must face a still greater challenge. They leave the group of their birth, and visit neighboring groups in search of a new home for the rest of their lives. This female, called Shin, has chosen Dr. Kano's group, but she must first pass muster with the formidable Haru. Female bonobos also use sex to forge strategic alliances with each other. The males, including Ten, readily mate with Shin. But Shin must still win the approval of Haru and the other females. Finally, Shin is embraced by a high-ranking female, who will act as her sponsor to the group. Shin settles down to enjoy the sugarcane within the circle of her new community. With equality between the sexes and the substitution of sex for violence, the social lives of bonobos are very different from that of their sibling species the chimp. While chimps may wage war. The gentle lives of bonobos show that violence, although part of our primate inheritance, is not inevitable. Their social lives are fascinating yet it is the mystery and potential of the chimpanzees' inner minds that intrigues us most. How deep is the mind of the chimp? Christophe and Hedwige Boesch have been mapping the chimpanzee mind through an extraordinary kind of tool use. There was this great day, it was beginning of December in seventy-nine. I was following chimps through unknown lands, I didn't know where I was anymore, they were drumming, screaming, I followed with my compass, behind. And, suddenly, there was great excitement and I was hiding under some vegetation and there was a clearing in front of me with a big tree, big branch sticking out and I heard some banging so I approached without making a slightest noise and I hear the chimps coming, they passed me, I could fee their warmth, I could smell them, they all started climbing up these trees with big tools in their hands and banging on something which I finally realized they were cracking nuts. The sight is unforgettable something of prehistoric times, the image of these great animals using these big tools. To crack nuts, the chimps seem to have grasped the concepts of hammer and anvil. The anvil is a tree root; the hammer, a wooden club, or sometimes even a stone. Although it may seem effortless, it takes a decade of practice before the chimps develop real expertise. When you look at these images of chimps cracking nuts, it looks terribly easy and people don't realize how difficult it is. I made an experiment: I asked a primatologist who came to visit me here, I gave him some nuts and a nice place in the forest and I told him, yeah, crack some nuts now. You will see how easy it really is. It took him 25 minutes to open the first nut. He took him 40 minutes to eat three nuts. And you can imagine, if you really have to fight 40 minutes for three nuts it's not worth it. I remember the very first time I saw a female mother who was looking at her five year old trying to crack a nut and she was fighting with a very, very strange formed club and she was changing her position all the time and changing the grip of the hammer and didn't succeed. And she was starting to whimper, not knowing what to do. And then the mother came, the infant immediately stepped a bit backward and the mother took the hammer and in a very slow motion move, she turned the hammer and just the move, this turning the hammer, took her a whole minute, so it was even slower than I did, and as to emphasize, that's the way you should hold the hammer and she cracked for some nuts for her and then left and the infant tried again with exactly the same grip as the mother. She still had some trouble to crack the nuts so she changed position, changed the place of the hammer, but kept all the time exactly the same grip as the mother showed her. So, that's really correcting an error in an infant which is really the highest form we would consider of active teaching and that just was kind of a surprise for the first observation in animal, for the animal doing that. A young chimp's tutor is its mother, who teaches it most of the skills it needs to survive. The Boesch's research has shown that female chimps are the most expert and dedicated tool users, which may shed some light onto the origins of tool use among our own ancestors. Already here we have a slight sexual difference in favor of females in that they crack more then males. Another technique to crack nuts up in the trees is much more often done by females and they have to anticipate bring the hammer up on a branch in the tree and then they have to handle it up there, hold the nuts in a fruit in the hand, hold the hammer, hold the baby and still crack somehow and eat these nuts. And then we have a nut species Panda nuts, very hard, you need stone tools to open it. Stones are a rarity in the forest, again, this technique is more often done by females. It could make you think that maybe tool use in our ancestors was also a female activity and the first tool users and tool invertors may well have been females. Females also transport learned skills between chimp communities when they move from group to group at adolescence. But, sadly, as chimp populations become increasingly isolated this kind of cultural exchange will come to an end. Only recently have researchers all across Africa realized that some of the differences between their study groups were cultural due to the invention and passing along of learned traditions. In the Kibale Forest of Uganda, Richard Wrangham has found that it is culture which enables some chimps to eat foods others must forgo. So, here we got a safari ant nest and in five years we have clear evidence that the chimps here do not every eat these, but in Tai and in Gombe this is what they do. A wand onto the nest and then sweep the ants up, biting, no neat test, you've got to be pretty quick and you've got to know what you're doing. Now, having just tasted them, I can understand why chimps like to eat them, but, on the whole, I'd prefer not to, myself. Every chimp group has its own unique tool kit. Only at some locations have they learned to use wands to capture ants or termites. At Tai, they use bone picks to dig out the marrow, just as our earliest ancestors did. They will also use a wodge of fruit as a sponge, to help squeeze out every trace of sweetness from the pulp. While at Gombe, as well as at Tai, chewed leaves make a sponge to quench the thirst at shallow puddles. We have only begun to realize the depth of the traditional knowledge generated by the various "nations" of chimps. One puzzling cultural practice is the eating of hairy and unpalatable leaves They ball them up in their mouths, forcing them down whole. Well, here I've got one of the leaves that is swallowed hole by chimpanzees. This particular one is the one that the chimpanzees tend to swallow, at dawn, why they do it at dawn is not certain. Well, one possibility is they're helping to remove worms. This is so new that we don't even know the name of this. We think it's part of a tape worm and it looks as though, when the chimpanzees have this tapeworm, they swallow the leaves in order to expel the tapeworm. Scientists are now searching for drugs among the plants they believe chimps take as medicine. We have long tested human drugs on chimps someday we may test drugs discovered by chimps on ourselves. Chimpanzee cultures also mold their methods of communication. Besides their calls, they use a symbolic language of gesture. Some gestures we hold in common a kiss soothes a little domestic discord. Others we seem to recognize two males clasp hands and raise their arms in a salute as they begin to groom one another. Other gestures, such a leaf grooming, we are only beginning to decipher. When a chimp wants to be groomed, they pick a leaf and just, uh, run the thumbs over it, sometimes bring a mouth to it and then drop it. What does this mean? Well, in functional terms, it means nothing, but it's a symbol. It's a symbol for the chimps. What it means to them is I would like to be groomed or sometimes it means I'm interested in you. If these gestures are truly cultural, we should be able to see them evolve as fashions change. Christopher Boesch believes he has. Leaf-clipping is a behavior where they take a leaf, makes a specific sound and in Tai they do it before displaying. The interesting thing is that, two years ago, chimps in Tai started for the very first time to leaf clip when they were making a resting period They were asleep, they would change position, would do some leaf clipping, and sleep again. A new context of use. And, interestingly the individuals have started to use the leaf clipping in this new context were younger or were females. There is much we could learn from the chimps, but we are running our of time. Poaching for meat and the logging of forests are driving them towards extinction. Today, Jane Goodall is fighting to save them and their heritage. We're finding that across Africa where different researchers are studying different chimpanzee groups, there are different traditions, different cultures and the tragedy here is that the chimpanzees are disappearing so fast, not only, eh, is it sad that the individuals are going, but their whole cultures are going, too and that's the area where we have most yet to learn. The group studied by Christophe Boesch is disappearing fast. The cause is a mystery. Only rarely does he find any evidence of their passing. It's only in one of the oldest female we had. And she was found by the group actually dead on the floor with her last baby dead and the oldest juvenile sitting nearby watching. The losses are tragic for the species, and for all involved. I have lost, in the last six years, about half of the chimps. There were 80, there are now only 40 left. So, it's a dramatic reduction and, but for us it's depressing, yeah, sure Predation and disease have always taken their toll, but death at the hand of man may prove too much to bear. We have some clear proof that poachers are killing chimps here in our group. And I have the feeling that the toll they pay to poachers is just too much and it's this part which is the causes of the decline of the population and, if that is true, it's very worrying not only for the study group but for all the chimps in this park. Each death is felt dearly. Yet it is when chimps are forced to confront death, that we seem to catch a glimmer of the chimpanzee soul. What is striking is that they feel compassion. I mean, they really feel the individual has something not normal and that they need help. In one case, I observed a fresh juvenile being killed by a leopard. So, you have an individual that looks actually very similar to a wounded one but he's dead and it was very surprising to notice that the chimps reacted totally differently, as if they knew this individual is not just injured, this individual is dead. And all the adult males stayed around the body for all this time, groomed it a lot what they would never do with a live juvenile and, in a kind of a way, asked for the other group members to show respect for the dead. And the only young that was authorized to come to the body was the younger brother of the dead. So, yeah, it makes you think what they feel and how they understand. We can only guess what this female, called Castor, understands about her own tragedy. Her infant is mortally ill. Since her baby is too feeble to cling to her, she resorts to carrying it with her foot as she climbs in search of the food she needs to survive. Still the baby clings to life. How do we really realize that somebody's dead? How would we realize if we didn't have all the science and all these things. So, I think, in a way, they certainly know that something, special is happening that they would like to fight against it, but that they can't and they realize it after a while. Finally, the emaciated form of her infant lies deathly still. Then with a gesture so human it's painful to watch, she seems to bid her baby farewell with a kiss. If chimps share with us the emotions that bring us to tears, perhaps they share others, as well. Jane Goodall wonders. Do chimpanzees feel perhaps a sense of awe, similar to that which must have lead to the first religions of our ancestors worship of fire, of sun, of rain, worship of rushing water that is always coming, always going, yet always here? Face to face with our nearest relations. Our mutual family history is glorious and tender, brutal and shocking. As humans, though, we are distinct, and must choose how our own nature is expressed. But it's clear that, for good or ill, we are part of nature just another of its promising but flawed creations. Through the study of the chimps, science, which once strove to set us apart from the rest of nature, has now brought us back within its fold discovering this mind in the forest. What grabs you is when you feel that there's an animal out there that has a human like mind that can solve problems, that has extraordinary social relations and has got this beginnings of the diversity of culture. It's when we see into the mind of the chimps that we get that strange tingle What it means in a deep way is that as long as these chimpanzees are surviving, humans are in touch with their ancestry and we know we're not completely alone |
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