On a calm afternoon in 1974, a young chimpanzee named Godi sat alone in Gombe National Park, Tanzania, eating fruit from a tree.

Without warning, he was swarmed by attackers. A patrol of six other chimpanzees had found him alone and decided to strike.

A male named Humphrey grabbed Godi’s leg to stop him from fleeing, and threw him to the ground. Humphrey held Godi down as  the others pummeled him, hitting and biting him over and over. After ten minutes of constant beating, Humphrey released Godi, and the attackers fled.

The chimp laid there, still, for many minutes. Finally, he stood and stared into the forest. Blood ran down his face.

He let out a long scream, and limped away. This was the last time that  Godi was seen in Gombe, and the attack marked the beginning of what’s now called the Gombe Chimpanzee War. The four-year conflict  pitted friend against friend, mother against daughter, and sent ripples through the community for decades.

Jane Goodall was among the researchers studying in Gombe at the time, and she was stunned by what followed. The same animals she had observed using tools and forming tight social bonds were apparently capable of the kind of sustained and organized violence that in humans, we would call war. So, how far back does our predisposition for this kind of violence go?

I’m Lindsay Nikole, and on my own channels, I talk a lot about evolution and zoology. This war is a perfect case study for some of the deeper questions in both of those fields. Although it happened 50 years ago, the Gombe Chimpanzee War continues to be one of the most shocking events in the history of primatology.

And in another part of Africa, it may be happening again. [♪INTRO] [Act I] Our story starts in 1960, more than a decade before the conflict began. A young Jane Goodall first arrived in Gombe, sent to study chimps by the famed paleoanthropologist Louis Leakey. Louis was a dynastic figure, the first of three generations of Leakeys to work on human origins research in East Africa.

He was the director of the  National Museum of Kenya, and was dead set on getting more researchers out into the field to study modern apes. And not just because modern apes are very cool. That is true.

But Leakey  thought that to understand the origins of the great apes and ourselves, we needed to know more about modern apes, too. And yes, chimps are a totally different species from humans, not the ancestors of humans. Our common ancestor was alive sometime between 6-8 million years ago.

So there’s a limited amount we can learn from their behavior and apply to ourselves. But it never hurts to learn more. “Well, when Jane first was sent to Gombe to look at chimpanzees by Louis Leakey, nothing really was known about their behavior in the wild. That’s Dr.

Anne Pusey, a researcher who worked in Gombe in the early 1970s. We wanted to talk with her to get a sense of what the early days were like, and what made the work done at Gombe so important. “And Louis Leakey was a paleoanthropologist, so he was interested in what our closest living relatives, how they lived and what that might help us understand about what the ancestors were like, that the bones of the different Homo species that he was discovering in Olduvai.” Aside from our direct ancestors, Leakey was interested in a fossil ape called Proconsul, which he argued was the earliest true ape. So it was the direct ancestor of us, chimpanzees, and all the other modern apes.

Proconsul had lived in an environment almost identical to the places  where modern chimps live, and which was especially similar  to Gombe National Park. So Leakey wanted to know more about chimps living in that environment as a proxy for his fossil ape. “So when Jane first went out there, she was really the first to be able to get close enough to the chimps to actually see what they were doing every day. And so absolutely everything was interesting to her and to Leakey.

And the early discoveries she made really excited people, that  they made and used tools, that they hunted animals, they hunted monkeys, and that they shared meat. And so these were all things which we know are important in human societies, and seeing that our close living relatives already did some of these  things was really exciting.” These discoveries completely changed our understanding of chimpanzees. But Jane had only gotten  to see them at a distance, through binoculars.

She knew that if she could get closer, she would be unlocking a totally different world. Her job was straightforward: Find all of the chimpanzees, and convince them to let her get close. But that wasn’t gonna be easy: chimps, like other wild animals, are not necessarily down to be followed around by humans, that is to say, strangers who have clothes on.

So before she could learn anything about them, Jane had to get them accustomed to her presence. One way she did this was by feeding them bananas, because who’s gonna turn down a banana? She wasn’t literally handing out bananas, though.

There were these two little  feeding stations not too far from the researchers’ camps where they’d stash the fruits, that they could open from a distance when the chimps got close. And put a pin in that, because we’re going to talk about the banana  feeding stuff again later. But for now, the thing to know is that the bananas were a key part of how the chimps got used to her; enough to let her follow them around.

With time, this turned into letting groups of researchers follow them around, too. And this is when the researchers started to understand what a day in the life of a Gombe chimp was like, away from the feeding stations and in their actual home environments. The Gombe forest is big, and there are more chimps than there are researchers to study them.

So a pair of researchers would pick one chimp to follow around, from when they got up in the morning until they made their nest at night. One researcher would take  notes of their behaviors on a form called a check sheet,  using specific behavior codes and writing down what  time every event happened. The other researcher would take broader, narrative notes, and include what the other chimps in the area were doing as well.

With time, you’d get a picture of the whole social network of the chimpanzees—who  likes to hang out with whom, which male is in charge, et cetera. And these records go back decades, all the way to the early years at Gombe.  So today, you could go back to a random day in 1970, and see what chimp took a bite of a fruit at exactly  what time, and then what time they took the next bite of fruit, and also if they spit a little bit of it out. That’s insane.

A check sheet from 1970  looks basically the same as one that researchers would  use today, which makes it easy to compare decades of data all at once. And with enough years of  data you can see how these social groups change, too.  Which is what Goodall and her colleagues started to see in the early 1970s. At the time, there were  three main chimp communities in

Gombe: the Mitumba in the north, the Kalande in the south, and the Kasekela in the middle. Kasekela is the group that Goodall had been studying since she arrived. And in the beginning of the 1970s, she could see something odd was happening. Researchers had known for a while that there were two cliques of chimps within Kasekela, based on who came to the feeding stations.

The members of those cliques would still interact with the group at large, just not as often. Gombe staff noticed that  the southern clique wasn’t coming to the feeding stations as often as the northern group would, even if they put out extra bananas to try and encourage them. The two groups spent less and less time together as the years passed, and even seemed like they were avoiding each other altogether.

Though the researchers didn’t know it, this was the beginning of a conflict that would get deadly. But before we get into all of that, we need to talk about chimpanzee social behavior. Chimps live in big groups of lots of males and lots of females.

They have a social pecking order where males are usually  higher-ranked than females, all leading up to the alpha of the group: the male chimpanzees who  get stuff like first dibs at the best food, the most  attention and grooming from others in their community, that kind of thing. So the opposite of what happens with self-proclaimed “alphas” in our communities. In chimp groups, the males  stay in the group they were born into, while the females  usually have to migrate into a new territory, to avoid inbreeding.

That means that males can gain more social capital over their lives, building more complex social networks with each other than the females do. Researchers can usually tell who’s the alpha based on the chimps’ social behaviors. They look for who does the  most dominance displays, where the chimps throw sticks around, puff up their hair and stuff.

And the rest of the group  will acknowledge the alpha by making a submissive sound called a pant-grunt, lowering their stance, or by… running away. And even the alpha may not win every contest. So for the most part, researchers tend to say that the chimp who wins the fights the most often is the alpha, even if other males might ruffle him up from time to time.

But the alphas don’t stay alphas forever. It’s not uncommon for a chimp to be the alpha for a few years at a time, but then as he gets older and weaker, he gets overthrown by a younger and stronger male in the group. Which brings us to another quirk about chimp social groups.

Even though their groups are bigger than those of a lot of other apes, you don’t really see everyone, all together, all at once very often. They have what’s called a fission-fusion social system: even though the whole community may be big, you’ll only see smaller groups hanging out at a given time. Some animals will keep their whole group together all the time, like a flock of geese or a herd of zebras or a flamboyance of flamingoes.

But chimps don’t do that. They’ll have big social  networks that can have dozens or even hundreds of  chimpanzees within a territory, but they’ll only get together  in much smaller groups of five or ten chimps, usually either to gather fruit or hunt for meat. Yes, meat.

Chimps will hunt down and  eat colobus monkeys, and at another research site called Fongoli, they’ve even been seen spear-hunting bush  babies for a quick meal. Chimps will also group up for something called a patrol, where a handful of  them, usually males, scope out the edges of their territory looking for any rival chimps. If they find any, they’ll either scare them off or attack.

We now know that they’re not  shy about killing members of rival groups if they  come across them, especially if the rival is outnumbered. And these territorial attacks can be absolutely heinous to witness. But the researchers at Gombe didn’t know any of this yet.

At the time, when Jane Goodall got to Gombe, she’d assumed that chimpanzees were a docile, vegetarian species. That was our understanding of chimpanzees. Obviously, that’s no longer the case.

The brutal attacks that they were about to witness were the very first chimp-on-chimp attacks ever seen by researchers. Now that that’s out of the way, let’s go back to the main story. Like we’ve said, the researchers at Gombe noticed that a group of males were getting cliquey starting back in 1971.

And in order to unpack what they saw, we asked Dr. Richard Wrangham, another researcher who was at Gombe at the time, to introduce us to the main players there in the early ‘70s. We’ll start with Mike, who was the alpha of the Kasekela group right up until around 1971. “The situation in the Kasekela community in the competition for dominance  was that after the old male Mike had been defeated, I think, by Humphrey.

But I'm not absolutely sure about that. I'm not sure if anyone  knows who it was that really toppled Mike. There was some tension between the rivals for the alpha male position.” So with Mike’s overthrow, there was a bit of a power struggle for who  would take the alpha status.

And the three main players in that struggle were Humphrey, Charlie, and Hugh. “Humphrey was a very brave,  bold, annoying character who I think was not very good at forming alliances with others, but was good  at fighting others himself. So he was one candidate to be alpha male. And the only ones who put up serious resistance to that, or the only one who  put up serious resistance to that, was a slightly younger male, Charlie, who had the advantage of having his elder brother, Hugh, as a very predictable ally.

And Hugh and Charlie, as I remember, spent the great majority of their  time traveling together.” The brothers Charlie and Hugh were agitators. Liked to stir the pot. And they were not particularly happy about Humphrey’s promotion. “I think it's fair to say that there would be unresolved interactions between Humphrey and Hugh and Charlie.

Now I think  there's a kind of complexity in understanding what's  going on here because it may well have been, and I think  it probably was the case, that Hugh and Charlie charging  together literally just inches apart as they sweep through this relatively open little area could  dominate and chase any other male including Humphrey. But  the complexity is that it seems as though it doesn't  really count if a male is dominated in an aggressive  interaction by two others. Humphrey can run away  screaming, Hugh and Charlie can sit where Humphrey had sat  and have their hair out and look proud and achieving.

But it's unlikely under those conditions that the  victim will actually give the critical sound, which is the pant grunt that signals unambiguously, okay,  you have defeated me and I acknowledge you as the dominant.” So even if Hugh and Charlie weren’t into Humphrey becoming the new alpha, the two of them together weren’t really able to do anything about it. And because of that, it  seems like Hugh and Charlie, and their friend group, started to spend more time apart from the rest of the pack. Another chimp that we need  to talk about is Goliath.

He was a highly-ranked male  in Kasekela, and had even been the alpha until some  time around 1964. But even after he lost that status,  it seemed that he was still pretty well-liked in the group. Dr.

Pusey recalls spending time watching him in the early 1970s, before the split. “Well, when I got to Gombe,  Goliath was obviously an oldish male. He was fairly  bald on top and he wasn't very high ranking, but he  was absolutely part of the group and he'd often come  to the feeding area and he'd groom with the other males. I spent quite a bit of time with Goliath partly because there was a young male, Sniff, who was an  adolescent at the time.

He was probably about 10 to 12  when I was spending time at Gombe and I was interested  in adolescent males and how they became independent and  how they joined the male group and Sniff used to  follow Goliath a lot and Sniff also tended to hang out with  those southern males. But Goliath also groomed with  northern males and there was another old male called Hugo. So Goliath was definitely part of the group, but he was low ranking when I knew him.” Goliath is one of the first  two chimps that Goodall observed making and using tools, by the way.

This is the finding that  catapulted Gombe and Goodall to household-name status. So Jane loved Goliath. And we also love Goliath.

Just keep that in mind. As tensions rose between the Kasekela males, the researchers started to see evidence of a rift forming within the group. The Southern group, led by Hugh and Charlie, would spend more time  grooming each other than they would with other members of the larger party.   And they even stopped coming  to the feeding stations.

Passing up free food just to avoid someone. Things were clearly getting very bad. That Southern group consisted  of seven males and three females, plus their dependent offspring.

There was Charlie, Hugh, Goliath, and Godi, who we mentioned before. Then there was Dé, Willy Wally, and Sniff, the young male Dr. Pusey mentioned.

The females were Madam Bee and her daughters, Little Bee and Honey Bee,  as well as Mandy and Wanda. By the end of 1972, it was clear that this group had completely left Kasekela, and at this point became known to researchers as the Kahama group. There were too many chimps  in the Kasekela group for us to name here, but the  ones that are a part of this story are Humphrey, Satan, Goblin, brothers Figan and Faben, Evered, Sherry, Jomeo, Hugo, and a female called Gigi.

The Kahama group occupied the southern end of what had been Kasekela territory, making Kasekela’s total turf a little smaller, but not enough to cause a ruckus about. So the two groups seemed to coexist like this for about a year, and while  their territories were right next to each other, there  weren’t any observed clashes between them. Until one  afternoon, in January of 1974. [Act II] Jane Goodall details the events of the Gombe Chimp War in her book, Through a

Window: My Thirty Years with the Chimpanzees of Gombe. And just as a warning, the descriptions of some of these attacks are  brutal. Like, really bad. It will become very clear that chimps don’t have war crime limitations.

So, buckle up. The first violent event between the two groups was that attack on Godi, which we talked about at the beginning of this video. It lasted about ten minutes, and while Godi did walk away from the incident, researchers never saw him again, leading them to conclude he died of his injuries.

The next Kahama chimp to be attacked was Dé. A patrol from Kasekela,  consisting of Sherry, Jomeo, Evered, and Gigi beat him  for at least twenty minutes. Dé was seen two months after this attack, still injured and emaciated.

While  researchers were able to follow him for a few days,  he eventually disappeared, so he likely died of his wounds. And while these first attacks were shocking, the third one blew them out of the water. In a bad way.

Because this time, the  raiding party found Goliath. The researchers still didn’t know why Goliath ended up leaving Kasekela. Most of the other males that left for Kahama had never been as highly ranked as Goliath had once been, even though that  was years before this war.

And in the case of Hugh and Charlie, they’d specifically been reaching for the alpha status that Goliath used to have. So it kinda makes sense why those males would want to start a new group. But for Goliath, the reasoning is less clear.

Like we said earlier, the chimps in Kasekela liked him enough to make him the alpha once upon a time. Goliath’s attack happened in February of 1975, a full year after the beating that Dé received. Five adult males - Figan and Faben, Humphrey, Satan, and Jomeo - charged him.

Faben reached him first  and held him to the ground. Then Satan and the rest of the group arrived, and they all stamped on his body, pummeled him with their  fists, and even lifted him off the ground, and threw him  back onto the forest floor. Then, Faben twisted Goliath’s  leg around and around, in the same way that chimps dismember colobus monkeys after they hunt them down.

Remember, Goliath was old,  and even a chimpanzee in his prime would have had low odds of survival after an assault like this. So it wasn’t unexpected that  he was never seen again. Then came the first female casualty, Madam Bee.

She was also pretty old, and had been disabled by an outbreak of polio. She and her daughters were attacked several times by Kasekela, the first of which happened in September of 1974. And after that first attack, something really odd happened.

After the Kasekela males were done attacking Madam Bee, her older daughter Little Bee followed the Kasekela group back to the north, leaving her mother and sister behind. Over the months that followed,  Madam Bee was accosted by northern males at least four times, and researchers often observed  her with fresh injuries. The final attack on Madam Bee was as brutal as those on any of the males.

This surprised Goodall and the other researchers, who assumed that the females who had joined Kahama would have been welcome to return to Kasekela. But when the patrol found Madam Bee in the fall of 1975, it was clear that wouldn’t be the case. Researchers arrived at the scene after the attack had already begun.

Figan, Satan, Jomeo, and Sherry were surrounding Madam Bee,  beating her ferociously. And watching from the sidelines… was Little Bee. She’d stayed with Kasekela  after that first attack, and would sometimes join Kasekela patrol parties traveling south.

So she watched as her companions attacked her mother. At one point, the males started to leave, and Madam Bee tried to stand. Satan and Figan charged at her and beat her again until she fell.

This happened again and again, until finally the males were done. After the attack, researchers searched for Madam Bee for two days, and only discovered where she’d hidden when they spotted Honey Bee, perched in the tree above her mother. She took care of her mom for four days, until Madam Bee passed away.

Honey Bee did survive this war, and would come back to Kasekela as an occasional visitor in the following years, returning to her birth group when she was fertile. But she never stayed. Researchers didn’t observe  the next attack firsthand, but local fishermen told them they’d heard chimps screaming somewhere in the forest.

Three days later, the researchers found Charlie’s body by a stream, covered with wounds. His brother Hugh had vanished back in 1972, without a trace. So it’s  unclear if he was attacked before the war truly began, or if he’d joined some other group, or just died of something else.

Another male named Willy Wally, who’d also been disabled by polio, disappeared  not long after, leaving only one male and two females in the Kahama group. Trapped between their former Kasekela group in the north and the Kalande to the south, there was nowhere for them to escape. The final confirmed attack in this war was against Sniff, the youngest.

A Kasekela patrol found him in November of 1977, and just as old age had not spared Goliath or Willy Wally, youth didn’t save Sniff either. Figan, Satan, and Goblin  were the first to reach him, and their excited shrieks brought Jomeo, Sherry, and Evered to the scene. By then Sniff was bleeding badly, and researchers watched as Satan drank blood from Sniff’s face.

Yeah. Satan and Sherry dragged him  by his legs down a slope, and the group continued their assault for several more minutes, until they decided the job was done. Researchers saw Sniff the next day, but never again, so he was presumed to have died of his injuries within a week of the attack.

The final two females were also never seen again, and while it’s possible they integrated into the Kalande group, it’s more likely that they too were killed by Kasekela raiding parties. I know this looks super complicated, but Little Bee and Honey Bee are still alive. In either case, the Kahama group had been completely eliminated.

So, that was horrific. I don’t think I’ve ever heard of something this brutal in the animal kingdom, excluding us. It’s hard to imagine what the aftermath of something like this was going to look like.

And as it turns out, it wasn’t even that great for Kasekela. Remember, the Kahama group’s territory was to the south, right between Kasekela and  the rival group Kalande. By killing their former  friends, Kasekela had knocked out the buffer between them  and the Kalande chimps, and created a territory vacuum in the middle.

The Kalande group moved north and claimed the former Kahama territory for their own, killing more of the Kasekela chimps and forcing them back towards the north. Two males died, including Humphrey, the alpha. After losing that territory to the south, they tried to move up into the valley where the Mitumba chimp group lived, in search of food.

The Mitumba group was larger and stronger than Kasekela, and by all accounts  Mitumba should have been able to fend off Kasekela. If they’d attacked, Mitumba could have ended them. But somehow, Kasekela  survived.

Barely, but survived. Things eventually calmed down, and an uneasy balance between the three groups was reached. After nearly ten brutal years, the Gombe Chimpanzee War was over. [Act III] So what came from this?

For the chimps and also for our understanding of chimp behavior? It’s taken researchers decades to try and put the pieces together of why this happened, and there’s still no one good answer. Fundamentally, it doesn’t make sense for a group of chimpanzees to do this.

They’re territorial animals,  and they rely on having lots of healthy males to defend their territory. So for a bunch of those males to just up and leave means that both groups are  smaller, and that leaves them even more vulnerable to further attacks. Which is exactly what happened to Kasekela after they killed off Kahama.

For some reason, they turned  on each other even though remaining together as a group  would have made them all safer. After that, Kasekela  suddenly viewed Kahama as such an unacceptable threat  to their territory that war was their only option. And researchers have, from time to time, used that word “war.” Some  scientists consider that an unacceptable level of anthropomorphism, describing something that  isn’t human as though it is.

But… is it really anthropomorphic? If humans split from one another and engaged in this level of sustained conflict, we’d call it a war over territory. And to be clear, this was at its core a territory issue.

Kasekela didn’t set out to murder their former friends and allies in cold blood. Chimps go on boundary patrols to protect their turf all the time, and when these patrols encounter rival chimps, they will attack. But the key word here is rival.

The southern chimps used to be considered part of Kasekela  and then they were not. Something changed to the point where Kasekela patrols found chimps that they knew, thought rival, and acted accordingly. That shift where allies became rivals is the thing that has baffled  researchers for so long, and the thing that demands explanation.

There’s genetic evidence  that permanent group splits like this one are super rare. In one study, researchers used the Y chromosomes from chimps from several sites to reconstruct how old their groups were. To make a long story short, they used the mutation rate of the Y chromosome to make a family tree for a whole group, and calculated how long ago that  chimp group was founded.

And the researchers estimated that their youngest community was about 125 years old and that their oldest two were both over two thousand years old. So yeah, these kinds of  splits just don’t happen out of the blue. Which makes  understanding what happened here all the more interesting, even today.

That’s why researchers,  including Dr. Pusey, went back through the old check sheets  and records to model the changing social dynamics in Gombe throughout the 1970’s to try to get to the bottom of it all. And they found that of all the things going on in Gombe at the time, there were two likely catalysts for the fighting.

One is that the dominance  struggle between Humphrey, Hugh, and Charlie was itself  the cause. Without group consensus on an alpha, it’s natural that chimps in Kasekela might have taken sides. And it definitely seems like there was some seriously messy social interaction going on between the group’s males.

But the other cause may have been that there was stress of a very…. particular nature in the group. See, chimps have this thing  where the females’ butts get all red and swollen when they’re ovulating, so the males know exactly when they have a shot at fathering offspring. In the early 1970s, most of the females in the group weren’t cycling.

They were either too old,  too young, or had recently given birth and hadn’t started ovulating again. There was also just an  unusually high proportion of males in the group at the  time, which meant that there were very few opportunities to breed. And that could have made these male chimps a bit… testy.

And to this day, the ratio of males to reproductively available  females in Kasekela has never gotten as high as it was before the fission. So it could be that it was  already a stressful time to be a Kasekela male, and  when you add on the fact that nobody could agree who should be the alpha… that could be the combination of rare factors that led to this split. But weirdly enough, that sex ratio may have been what saved Kasekela from Mitumba, too.

See, even after the losses in all these years of fighting… they still had  a lot of male chimpanzees. And in particular, they had  a lot of adolescent males. While younger males may not be great in a fight, they sound just like full-grown adult males when they’re making their territorial calls.

It’s possible that they managed to scare off Mitumba because they sounded like they’d be harder to fight than they really were. So a really unique set of circumstances probably led to a really unique fission event. We can’t know for sure, but it’s still worth trying to understand what  made everything boil over.

Which brings us back to the controversial banana feeding that I mentioned earlier. See, there’s an idea floating around that the banana-feeding caused two separate groups to temporarily hang out with each other in order to get to those bananas. Some researchers even argue that this wasn’t a group split at all, and was just a temporary banana-based alliance falling apart.

But this study looked into that too, and they found that there was no correlation between changes to the banana-feeding schedule and increased tensions between the two groups. The idea that they were always two groups also falls apart when you consider Goliath. He was literally the alpha of Kasekela, so if Kahama had always been its  own group, he wasn’t in it.

It makes way more sense that these chimps were in one cohesive group until the alpha shakeup caused them to split. Part of what makes the Gombe Chimp War so confusing to researchers is that, for decades, it was the only time that anyone had seen anything like it happen. And a big challenge is that when your sample size is one, there’s only so much you can really learn from the thing.

But Gombe may not be totally unique after all. Researchers at a site in Uganda called Ngogo think there’s a chimpanzee community split happening there today, with similarly bloody results. Just like in Gombe, they’ve started to see certain group members spend more time with each other than they do with others.

They’ve seen three separate subgroups or neighborhoods  forming: One in the west, one in the east, and one in  the center. But for a long time, these groups were  pretty chill with each other. “But then in the summer of 2015, was when everything changed.” That’s Aaron Sandel, who spoke with us from Ngogo where he and his colleagues  are studying what seems like another active split and conflict. And by active, I mean some of the action was happening during our interview. “There might even be a territorial conflict happening just to the south.

We have a WhatsApp where we all communicate. And I heard that the Westerners were traveling east this afternoon…” Yeah, I'm pretty pretty sure there's a territorial interaction. Hopefully, they don't kill any of the other chimps. ” Like I said, active.

Aaron gave us the breakdown of what’s been happening in Ngogo over the last few years. “There was a day that I  was with a big group of the Western chimpanzees, and  they were traveling from the far west of their range to the center of the territory. And all of a sudden, they got nervous. They became quiet.

They  were sort of reassuring each other with a touch. Some  of them were grimacing. And they were acting like they were hearing stranger chimps that they wouldn't  know, that they would have these territorial conflicts  with.

But we were in the middle of the territory. I  was starting to hear other chimps, but it must have been the chimps from the central neighborhood. And sure enough, it was, and John Mitani and another researcher, Rachna Reddy, were with them.

So the central chimpanzees  were in earshot, and for some reason, the western  chimps were acting as if they were nervous, more nervous  than usual. And then when the central chimps came into  view, rather than reunite in typical fission-fusion fashion, the western chimpanzees ran and the central chimpanzees chased them. And nothing like this  had been observed before.” Ever since that day, when  members of the western group encounter the central or  eastern chimps, they put on threat displays and make aggressive calls, just like they would do when encountering a chimp from a rival community.

And these displays have escalated to full-on violent attacks. What’s even weirder is that so far, this aggression has all been coming from one direction. “It's the Western community. It's the Western chimpanzees who have done all the attacks, all the lethal attacks.

And initially  it was both Western and Central chimps that would  engage in these territorial patrols. But after the second lethal attack, it's like the central and eastern chimpanzees, they stopped patrolling to the west. I don't know if it's out  of fear or something else, but it's almost like they've given up.

They don't really defend their territory and they definitely don't go on the offense. So it's the Western chimpanzees who are doing all the offense, doing all the lethal attacks. ” Which is interesting, since  that’s the same pattern we saw in Gombe, where only the Kasekela chimps continued to patrol their newly contested border. Kahama never seemed to patrol further north.

And even though all this started at Ngogo back in 2015, researchers still aren’t completely sure why it’s happening. So to try to get a better sense of it all, they’ve tried to identify  any major shakeups in the group that happened around  the time it all kicked off, just like that 2018 paper  did for the Gombe Chimp War. They’re still in very early  days of unpacking it all, but there’s one possibility that, if true, would also shed light on the events of Gombe.

See, right before all these  events unfolded at Ngogo, there was a dominance  hierarchy shift, resulting in a chimp named Jackson becoming the new alpha. In fact, the very first day that researchers saw Western chimps treating central chimps so strangely, the central group they’d happened across included Jackson. So if a dominance upset is  part of the story at Ngogo, that lends support to the idea that it was part of the story at Gombe, too.

But researchers aren’t sure of that. And there are lots of reasons to think the Ngogo situation isn’t a perfect parallel. There are a lot more chimps at Ngogo than there ever were in Gombe, for example.

So it isn’t exactly apples to apples, or bananas to bananas. Even though having two chimp conflicts to study is better than one, that still isn’t all that much information. So it’s hard to tell what else we can even learn  from this second event.

It’s worth pointing out again that a lot of the violence that happened during the Chimpanzee War sounds really, really bad. Like, drinking blood off your enemy’s face feels like a Game of Thrones episode. But there’s no evidence that the attacks in this war were any worse than what rival chimps without any history would do to each other.

For instance, in 2005,  researchers recorded a chimp attack in Loango National  Park, Gabon, that happened right outside their camp.  The lone victim was found dead, and his genitals were torn from his body and tossed twenty meters away. DNA evidence found that this lone chimp was in all likelihood not a part of  the group that attacked him, so this kind of attack is  just par for the course when it comes to how chimps deal with rivals. And that gets us back to  the fundamental difference that’s at the heart of both  the Gombe war and what’s happening in Ngogo.

Chimps that spent their whole lives together stopped  seeing each other as allies, and treated each other the  way that they treat rivals, with these brutal and horrifying attacks. But we asked Richard Wrangham about how different these attacks were from  the ones he’d seen in other places, like his main study site which is called Kibali. And he had something  really surprising to say. “The Gombe attacks seem in some ways to be even slightly inhibited compared  to the attacks that have been documented so richly  elsewhere.

And what I mean by that is that the Gombe  attacks in every case led to a victim that was still  alive at the time the attacks stopped. And then they crawled away and died maybe hours, maybe days later. Whereas we have quite consistent killings on the spot in Kibali.

So I don't think there's any  evidence that the attacks were any more vicious in Gombe than elsewhere as a result of them coming on  victims that they had known personally for some time.  And in fact, they might even have been slightly less so.” We tend to think of war as an “us” thing, with generals and weapons and organized battle lines. But whether the Gombe  conflict rises to the level of a war or not, maybe there’s  also a hint of something else people think of as an “us” thing: Mercy. So there’s a lot we didn’t even get to talk about with this, and there are a lot of big questions left unanswered.

And of course, we all wanna know what this says about humans. There’s a temptation for us to take things that chimps do and use them to explain human nature. After all, that was Louis Leakey’s whole deal— study the chimps to learn about ourselves.

But that’s probably not the  right way to look at this. For starters, even if this did mean that humans have some  biological basis for warfare, that wouldn’t make it morally right. Wild animals do lots of things that are completely natural, but that doesn’t make them ethical, at least, not if humans did them.

Nobody is getting away with murdering their spouse by saying that praying mantises kill their mates after sex, too. And chimps are not humans. Like I said, we didn’t evolve from them.

But even for chimpanzee researchers, it’s still a challenge not  to draw connections between what we see in them and what we see in ourselves. Many say they struggle to keep their objectivity when it comes to studying these animals. They’re our closest living relatives, after all.

When it comes to warfare, we see something uncomfortable in this parallel. Something dark, disgusting,  and a little too familiar. Maybe we can think of what happened in the chimp war as a mirror—the conclusions we reach depend on what we wanted to see.

The shocking violence is one thing, sure, but there’s more to this story. There’s that idea that some  of the chimps held back, perhaps out of recognition  of their former groupmates. And there’s the tenderness of Honey Bee, caring for her dying mother until she passed.

The fighting in Gombe through the ‘70s was brutal, heartbreaking, and, in many ways…. Pointless. Nobody ended up any better off than they started, and many ended up dead.

Maybe the takeaway here is the sadness that this whole story leaves us with. Even if there is some fundamental human tendency to go to war, we also have the capacity to grieve its losses, to question its purpose, and to try to prevent it from happening again. If we only learn one thing  from the Chimpanzee War, it’s that the costs of war are devastating, for their species and our own. [♪OUTRO]