WAR AND KIDNAPPING, killing and cannibalism: How inappropriate—how jarring—those words seemed as I stood in a tree's shade looking out across the glinting waters of Lake Tanganyika.
Behind me, where the westering sun had turned the tall grass into a sea of gold, a large group of chimpanzees was feeding. The scene was utterly peaceful, as peaceful as it was on a day 17 years earlier when I had first set foot in what is today Tanzania's Gombe Stream National Park.
Yet now I had new knowledge—now I knew that there, among those dark mountains across the lake in Zaire, moved terrorist forces, armed men who had raided Gombe in the night and left haunting fear behind. And I knew that some of our chimpanzees, so gentle for the most part, could on occasion become savage killers, ruthless cannibals, and that they had their own form of primitive warfare.
Yes, I recalled all this. Even so, in the quiet of the tropic evening I could relax, back again in Gombe—back home. Many old chimp friends were there, familiar members of the community that has been the subject of scientific study, under my direction, since 1960.
Melissa and her 7-year-old daughter, Gremlin, were enjoying their last meal of the day, the yellow blossoms of the msiloti tree. Nearby sat my old friend Fifi. I had first known her as an infant: Now she was mother of two. Fifi's older son, Freud, was playing a wild game with his friend Prof, a 6-year-old like himself. As they sparred and grappled, I heard outbursts of chuckling chimpanzee laughter from Prof as the bigger, stronger Freud dug tickling fingers into his playmate's neck or groin.
Passion and Pom, Prof's mother and adolescent older sister, occupied the same tree. Five of the community's six adult males were in the group. Figan, top-ranking male, fed in another tree with Humphrey.
There was a sudden swishing of branches behind me. I looked around at a bristling figure, head and chest just topping the grass, eyes glaring. He swaggered there a moment, working himself up. Wham! With a sudden lunge he slammed my back with both hands and charged off, slapping and stamping the ground. Satisfied with his display of male superiority, he climbed a tree near Melissa and fed.
This was Goblin, Melissa's 12-year-old son, now on the brink of social maturity. In adolescent male chimpanzee style, he had bullied and blustered at the adult females until they had begun to defer to him.
When the chimps moved on into the forest, I followed close behind and watched as they made their tree nests for the night. There were 21 individuals all told, including the infants. Such a group is not stable: Soon, perhaps next day, the chimpanzees would be scattering in the small temporary groups of three to six that are most common in their society.
Why do my helpers and I continue to observe the chimpanzees at Gombe after nearly two decades? Partly because chimpanzees are fascinating creatures with advanced brains and complex behavior. Their life expectancy is probably between 40 and 50 years in the wild. The females give birth only once in five or six years (unless a baby dies, and then the mother usually conceives again within a few months). Also, there is such individual variation among them that a very long-term study is necessary if we are to understand their behavior.
Beyond all this, chimpanzees are more like humans than are any other living creatures. There is the hope that knowledge of their ways and habits may help us in understanding our own.
Physiological similarities, both biochemical and anatomical, between humans and chimpanzees are remarkable. The structure of the chimpanzee brain is amazingly close to our own. The chimpanzee life cycle is not very different from ours—five years of infancy, then a period of childhood, followed by adolescence from about 9 to 14 years. Old age sets in at about 35 years. As among humans, affectionate and supportive bonds between mothers and their children, and between siblings, may persist throughout life.
Chimpanzees use more objects as tools and for more purposes than any creatures except ourselves. They may show cooperation when hunting for food, and when a kill is made (usually a monkey, young bushbuck, or young bushpig), adults may share the prize with one another and with offspring. Friendly social gestures include holding hands, patting one another, embracing, and kissing. Those who have worked closely with chimpanzees agree that their emotions—pleasure, sadness, curiosity, alarm, rage—seem very similar to our own, though this is difficult to prove.
And so we carry on, aided by the National Geographic Society, which strongly supported our work in earlier years. We recently celebrated another anniversary of my first landing on the shores of Gombe, with my mother, Vanne, back in 1960. On the pebbly beach of the lake all the staff of the research center, together with their families, gathered round a big fire. We spooned out huge helpings of rice and stewed goat from the great cooking pots. My husband, Derek, my son, Grub, and I sat on the beach and, like the others, ate with our fingers.
After the feast, as I listened to rhythmic native songs, I recalled that day when I first arrived in this place, strange in the beginning, often inhospitable. I conjured up my first three chimpanzee friends, David Greybeard, William, and Goliath—all three dead now, but vivid in memory. I thought back to 1964, when my first assistant had arrived to help record chimpanzee behavior. Many of the chimps had become accustomed to the presence of humans and, in order to make observation easier, we had started a banana feeding station.
Ten years later, at the 1974 anniversary, what a different Gombe it had become. About twenty students mingled with the Tanzanian field assistants around the fire. Mostly they were from the U. S., but some came from Europe and from the University of Dar es Salaam in Tanzania.
In my mind I contrasted the happy 1974 celebration with the one in 1975. I wish I could forget parts of the year that intervened. It was in 1975 that four of the students were kidnapped by a rebel group from Zaire. They came across the lake, about 40 armed men in a little boat, at night. They took the hostages and chugged away into the darkness. Two agonizing months passed before the last of the four was finally released.
In 1975, therefore, it was a small and somewhat bewildered group of people that gathered around the fire. There were no students; it was no longer safe for non-Tanzanians to work at Gombe. The Tanzanian field assistants felt lost without the students to guide them: They had not yet realized how much they themselves were capable of contributing.
Yet that 1975 anniversary, somber though it was, marked the start of a new era for Gombe. During the awful time when the students were held hostage, the Tanzanian field assistants had struggled on, maintaining the daily records. Then, when the young people were safely back with their families, Derek and I had set to work to start a new research program at the old station. Gradually, as the seasons passed, the Tanzanian staff developed a new self-confidence and with it a new enthusiasm and reliability. Today Gombe is as flourishing a research center as ever it has been.
Concern for Humans Prompts Study
Recent years have brought an increased public awareness of the horrors of human aggressive behavior and a growing fear of what a terrible fate this aggression may bring to the world. This concern in human society has led to an upsurge of interest in the aggressive behavior of nonhuman animals.
Threatening gestures and calls are more frequent in animals (including man) than are actual physical fights. This is certainly true in chimpanzee society.
Of course, fights do break out. The most common causes are competition for status, defense of family members, and frustration that leads an individual who has been thwarted by one stronger to turn and vent his aggression on a smaller or weaker bystander. Sometimes, not often, fights may break out between individuals competing for food, or between males competing for the same female. Males may attack females seemingly in order to drum into their victims, again and again, that theirs is a male-dominated society.
While fights between members of the same community may look ferocious, we have seldom observed them to last more than a minute. Only rarely do these conflicts result in serious wounds. Disturbingly, though, in the past few years we have found that fights between individuals of neighboring communities may be characterized by extreme brutality and may occasionally lead to deaths.
A chimpanzee community has a home range within which its members roam in nomadic fashion. At Gombe the home range of our main study community has fluctuated between five and eight square miles. The adult males, usually in groups of three or more, quite regularly patrol the boundaries, keeping close together, silent, and alert. Sometimes they climb a tall tree and stare out over the "hostile" territory of an adjacent community. As they travel, they may sniff the ground or pick up and smell leaves and twigs. They seem to be searching for clues to locate strangers.
If the patrol meets up with a group from another community, both sides, after exchanging threats, are likely to withdraw discreetly back into home ground. But if a single individual is encountered, or a mother and child, then the patrolling males usually chase and, if they can, attack the stranger. Ten very severe attacks on mothers or old females of neighboring communities have been recorded since 1970; twice the infants of the victims were killed; one other infant died from wounds. Curiously, young childless females may actually leave their natal community and, temporarily or permanently, join another.
For reasons yet undetermined, in 1970 our main study community began to divide. Seven males and three females with offspring established themselves in the southern (Kahama) part of the home range. During the next two years these individuals returned to the north less and less frequently. By 1972 they had become a completely separate community.
For a time the situation seemed fairly peaceful. If groups of the northern (Kasakela) and southern communities met near their common boundary, the males would display, calling loudly, drumming on the trees, dragging branches as they charged back and forth. These displays served to persuade members of the neighboring groups to turn back into their respective home ranges.
Then, early in 1974, a gang of five chimpanzees from the Kasakela community caught a single male of the Kahama group. They hit, kicked, and bit him for twenty minutes and left him bleeding from innumerable wounds. Field assistants later searched for days for the victim, but he was never seen again.
A month later another prime Kahama male was caught by three from Kasakela and severely beaten up. A few weeks later he was found, terribly emaciated and with a deep unhealed gash in his thigh. That was the last time he was ever seen.
Violence Claims Author's FavoriteIt distressed me deeply that the third victim in this outbreak of murderous violence was my old friend Goliath, who had been one of those to move south. At the time of the attack he was very old, his head almost bald, his body shrunken with age. The five males who set upon him beat him so severely that afterward he could not even sit up. The following day all the students and field assistants searched for Goliath to see if he might be helped. But he, too, was never found.
The next to be killed was an old female, Madam Bee. The four males who caught her continued their attack until she was inert. Somehow she managed to crawl into thick undergrowth, where she hid so effectively that the field assistants didn't find her for three days. Her whereabouts was given away by her 10-year-old daughter, Honey Bee, who was keeping her mother company.
Hilali and Eslom of the Gombe staff took bananas and offered water, trying to give the old female some comfort. Honey Bee stayed with her mother until the end, grooming her and shooing the flies away from the many festering wounds. But Madam Bee died five days after the attack. Nearly two years passed with no further violence observed between the two communities. Then, early in 1977, the aggressors claimed Charlie as another victim. After the fight his body was found, scored by wounds, lying in a stream. By then it was almost certain that only one of the southern males, Sniff, still survived. (Two males had died earlier, apparently of natural causes.) At the end of the year he, too, was finally caught. Five northern males pounded on him and left him with a broken leg and bleeding from countless wounds. He, too, managed to hide, but could not have survived.
It seems that we have been observing a phenomenon rarely recorded in field studies—the gradual extermination of one group of animals by another, stronger, group.
Why these brutal attacks? The northern males were not defending their own territory, since all the attacks except one were deep within the southern community home range. On the other hand, the aggressor males, before the community split, had access to the area that the southern community took over. If they were merely trying to reclaim territory they had lost, then they have certainly succeeded. Not only Kasakela adult males, but also females and youngsters, now travel, feed, and sleep freely throughout the southern area.
Chimpanzees are creatures of extremes: aggressive one moment, peaceful the next. Two days after the attack on Sniff, I watched Frodo, 1 1/2 years old, totter out to greet Jomeo, perhaps most vicious of all in the intercommunity fights. Frodo looked up at the huge male, and Jomeo gathered the infant into his lap and began to groom him.
A month later I watched as young Freud started a play session with his powerful uncle, Figan. Soon Figan was pacing round and round a bush, Freud grabbing at his legs. Once each time around, Figan, laughing, turned a complete somersault. Then little Frodo joined in. Their mother, Fifi, relaxed as always, lay sprawled on the ground and watched.
In the wild the young female chimpanzee learns about babies by watching mothers and, when allowed, by carrying infants, playing with them, and grooming them. We have never known a totally inefficient mother at Gombe.
Occasionally, however, we see what happens when a mother does fail her child. It happened with Flo and Flint. In 1964, when her daughter, Fifi, was about 6 years old, Flo gave birth to Flint. Flo was an excellent mother, affectionate, tolerant, and playful—and also a high-ranking and aggressive female.
When Flint was about 4, Flo suddenly began to show her years. (We estimated that she was in her early 40's.) Flint, living amid a large supportive family, had become like a spoiled human child. When Flo, in an effort to wean him, tried to prevent him from suckling or riding on her back, he would throw violent tantrums. He would even hit and bite his mother, behavior rare in youngsters. Flo, often seeming to lack the energy to cope with Flint's aggression, would give in.
In 1968 Flo gave birth to a female infant. Her problems with Flint increased. Youngsters normally become quite independent after the birth of a sibling, but Flint persisted in riding on Flo's back, despite the new baby clinging below, and he insisted on pushing into the family nest at night.
When the baby was 6 months old, Flo became very ill. Worried because she had not been seen for a few days, we searched and found her lying on the ground, unable even to climb a tree. The baby had disappeared. Flo recovered, and it seemed she was then prepared to accept Flint's infantile behavior. In some ways he seemed to fill the place of her lost baby.
Four years later Flo died. Flint, 8, was still sleeping with her at night. He had only stopped riding on her when she was unable to support his weight. Flint immediately became lethargic and depressed. He scarcely ate, and seldom interacted with another chimpanzee. In this state he fell sick.
Fifi showed concern for her younger brother, grooming him and waiting for him to follow her. But she had her own infant to look after, and Flint failed to respond. It seemed that he had no will to survive without his mother. Three weeks after Flo's death, Flint himself died.
Mother Maintains Constant Vigil
Fifi's effort was an example of why she has always been a special chimp for me. Now she is an excellent mother, affectionate, tolerant, and playful as Flo had been. Sometimes as her two sons, Frodo and Freud, romp with a potentially dangerous baboon, it seems that she is overly permissive. Yet she is watching constantly; if danger threatens, she retrieves Frodo swiftly.
Today Frodo watches everything Freud does and often tries to imitate him. Owing to constant association with a 7-year-old brother and his mother's permissive yet protective nature, Frodo at 2 1/2 is the most precocious infant I've ever known at Gombe. In about twenty years one of these two brothers probably will become the alpha, or top-ranking, male of the community. The support of a brother may be very significant in attaining this seemingly highly desired position.
Goliath was the first alpha male that I knew. He lost his dominance in 1964 to Mike. A small male, Mike embellished his charging displays by banging empty kerosene cans and so intimidated the other males with the racket that in just a few months he bluffed his way to the top. We never saw him actually fight any of the other males, not even Goliath.
Mike reigned for six years, then was overthrown by Humphrey. Exceptionally aggressive, Humphrey showed none of Mike's ingenuity—nor did he need to. He simply charged at Mike one day and attacked him. It was an easy victory, for by then Mike was beginning to age.
Humphrey's reign, however, was shortlived. After two years the coveted top position was claimed by Figan. Figan, like Mike, has small stature but plenty of intelligence. Instead of trying to tackle the heavier Humphrey on his own, Figan made use of his supportive relationship with his brother Faben.
When Figan challenged Humphrey, Faben almost always joined him, and the two brothers displayed in unison. Figan avoided confrontation with Humphrey when Faben was not around. Humphrey became more intimidated each day, and eventually Figan grew bold enough to attack. It happened late one evening. Figan, displaying back and forth in a tree, worked himself up to a frenzy, then hurtled down on Humphrey, who was already in his leafy nest. Together they crashed to the ground. Humphrey escaped and ran off, screaming. Figan, at the age of about 21, took over top status and still maintains it today, seven years later.
Quite clearly, many of the male chimpanzees expend a lot of energy and run risks of serious injury in pursuit of high status. To what end? In some primate societies the advantages of alpha status are reasonably clear-cut. The top-ranking male baboon, for instance, will sire a high percentage of the infants in his troop. True, the alpha male chimpanzee can often inhibit other males from mating with a particular female in his group. But if his attention is distracted, the other males will take immediate advantage. Moreover, almost any adult male chimp can persuade a female to accompany him, away from the other males, on a consortship. If he is successful, she will not be available to the alpha male at the time she is likely to conceive.
The top-ranking chimpanzee can claim right of access to choice foods most of the time. Yet when there is a shortage of food, in the dry season, the chimpanzees break up into small foraging groups: In each such group one individual will rank highest and take the best food site—the alpha male will have no special advantage except in his own mini-group. Perhaps to acquire a position exempt from attack by fellow chimps (who almost always show him deference) is reward enough.
Often, after supper, our assistants come to tell us what they have seen during the day. We sit companionably on the soft sand outside the house, with the lake waves lapping or sometimes slamming onto the shingle, and listen to the recounting in soft Swahili of the activities of the chimpanzees. We discuss the possible meanings of some of the stranger events, or the results of a particular program of analysis.
Killing, Cannibalism: Crimes of Passion
When we are back home in Dar es Salaam, the news from Gombe comes to us daily by radio.
One morning—it was in August 1975—we heard that Gilka had given birth to an infant. I was delighted, for her first baby had mysteriously disappeared when just under a month old. Three weeks later the news about Gilka was tragic and horrifying. As we listened to the distorted voice, speaking to us from 700 miles away, we couldn't believe what we were hearing: "Passion has killed and eaten Gilka's baby."
We got the full story on arrival at Gombe. Gilka had been sitting with her infant when suddenly Passion, another mother, had appeared and charged her. Gilka had fled, screaming, but Passion, chasing and attacking her, had seized and killed the baby. Passion had then begun to eat the flesh, sharing her gruesome meal with her own two offspring—adolescent daughter, Pom, and infant son, Prof.
The following year Gilka gave birth for a third time. To our utter dismay, this baby met the same fate. The circumstances were more dreadful, for it seemed that Pom had learned from her mother: This time it was the daughter who seized and killed the infant. Again the family shared the flesh.
A month later Melissa's tiny new baby was killed, again by Pom, after a fierce fight between the two mothers.
I began to feel desperate. We knew for certain that three babies had been killed. Still others had vanished—like Gilka's firstborn. We began to suspect that Passion and Pom were responsible for all these deaths. It came to me suddenly that in three years—1974 to 1976—only a single infant in the Kasakela community had lived more than one month, Fifi's son Frodo.
What was the reaction of other chimpanzees in the community to Passion's behavior? We don't know how many, other than the victims, were aware of what was happening. No other chimps were nearby during the three killings that were seen. We did find, however, that the adult males, when they were around, would defend a mother and new baby.
How long had Passion been killing babies? How much longer would she and her family persist in this horrible behavior?
One day in July 1977 I followed Passion and her family as they left camp. Pom and Prof, who had moved ahead, presently climbed into a low palm tree. Passion sat below, looking up. Suddenly I realized that there was a third chimpanzee in the tree: a young female, Little Bee. Pom was very close to her, staring intently at something in her lap—a tiny newborn baby.
Cautiously Pom reached a hand toward the infant, then glanced down at Passion. I could see what was going to happen. So apparently could Little Bee, who had already lost one, probably two, infants. Uttering squeaks of fear, she began to edge away toward a tall tree close by.
I looked again at the baby, almost hidden in its mother's embrace, and picked up a big stick. Feeling totally inadequate, I reached up and tapped Pom's arm with my stick. She pushed it away in an irritated manner, scarcely giving me a glance. At that instant Little Bee leaped into the next tree, Pom and Prof close behind. Passion was already racing up the trunk. Helplessly I shouted and threw things, but the second tree was tall, and already screaming and fighting had erupted high above. I do believe, though, that the commotion I made added to the general confusion and helped Little Bee escape. Passion and Pom searched for a full hour before moving on, but they did not find her.
We decided to have Passion and her family followed every day for several weeks. Melissa was again in advanced pregnancy. Perhaps our field assistants could help if Passion made another murderous attack after Melissa's baby arrived.
Two months later Passion was still being followed. Melissa simply got bigger and bigger. Then, in October, we received another astounding message: Melissa had finally given birth—to twins!
Double Trouble for Melissa
Two weeks later Derek and I got our first glimpse of the new arrivals. Melissa cradled them close, shielding them with her arms and legs. By evening, after Melissa had made her nest for the night, I had realized the immensity of her task. Most new infants can cling to the mother's chest and belly without help for long periods of time. The twins gripped well enough, but they kept clinging to each other. One would pull the other loose from Melissa's hair and, uttering loud cries of distress, both would start to fall. Melissa had to give them almost continuous support.
I spent several days with Melissa. Despite her burden, she managed to keep up with one or another of the adult males, who would protect her. Most frequently she traveled with Satan, who probably is the father of the twins, for he and Melissa had been away from the group together at the likely time of conception.
Once, as I watched, Pom and Passion joined Melissa's group. Stealthily Pom approached Melissa, high in a palm tree. Melissa uttered loud, urgent screams. Fortunately Satan was nearby. Melissa made a terrific leap to the next tree—it looked most dangerous for the twins—and sat close to Satan, her hand on his back for reassurance. Pom followed halfway, then stopped, foiled.
That time Passion did not join Pom. Perhaps she knew that Satan would have interceded. She was probably hesitant, too, because she herself was pregnant and had become lethargic. It was this that probably saved the twins. Sometimes the two families met when no adult male was nearby, but Pom, not yet fully grown, could not tackle Melissa on her own.
When I visited Gombe early last year, the twins, Gyre and Gimble as we named them, were 4 months old, inevitably tiny and backward, but alert and healthy. Passion had borne her infant too. Hoping his birth would bring to an end his mother's horrible behavior, we called him Pax. He was the largest infant I'd ever seen—at 1 1/2 months already bigger than either twin. Some of the field assistants attributed his size to the bones and blood of murdered infants!
The day before we left, I followed Melissa as she traveled with her family across a lush valley. When her mother stopped to rest, daughter Gremlin groomed her and, cautiously, touched one of the twins. If only Gremlin would become fascinated with the babies, and if Melissa would tolerate this, Gremlin could be very helpful in raising Gyre and Gimble.
All at once Melissa got up and ran through a tangle of vines. Wriggling after her, I was just in time to see her greeting Passion. Both mothers, voicing small tense screams, rose upright to embrace. Pom stood watching but did not approach. The two families then went their separate ways.
I felt reassured; the worst seemed to be over. Passion was occupied with her own infant. Pom herself would conceive during 1978—a son, Pan. It now seemed that Melissa had little to fear from that family. Still, she would have a hard time in the dry season, for then, when food is often scarce, the twins would be bigger and need more nourishment. But we would try to help.
Study Will Chart Chimps' Progress
This year and next, which will close the second decade of research at Gombe, we shall be following the progress of Fifi and her two sons, of Passion and her family, and of Melissa and her sons, Goblin and Gimble. Sadly, Gyre died last August, apparently of pneumonia. But in all three families we shall have a record of the development of the relationship between brothers from the very beginning—something we've not documented before. We shall watch Freud and Gremlin as they enter adolescence. Probably a new alpha male will rise to power.
The late Dr. Louis S. B. Leakey predicted, when I set off to Gombe in 1960, that I was starting a study that would take ten years; I was young, and that seemed a lifetime. Now I realize that the first ten years were just a beginning. Certainly our picture of chimpanzee behavior would be very different if the work had ended in 1970. We had no notion then that chimpanzees might, deliberately and systematically, kill one another.
It is sobering that our new awareness of chimpanzee violence compels us to acknowledge that these ape cousins of ours are even more similar to humans than we thought before.
What new and startling developments, I wonder, will the third decade of our study disclose?