Lethal attacks on gorillas by chimpanzees (part 3 of 4)

In part 2 of the story “Lethal attacks on gorillas by chimpanzees”, the Rekambo group of chimps attacked a family of gorillas, kidnapped their baby, and beat it to death. It was on February 6th, 2019, and it was the first time any scientists witnessed the murder of a gorilla by chimpanzees. World-renowned researcher Lara M. Southern was present during this event. In part 3, she tells the story of when she witnessed the hostilities escalate to an even more vicious level.

Lethal attacks on gorillas by chimpanzees (part 3 of 4)

Even though Lara and the other scientists were entirely shocked by the first attack, she knew it was important to relay the information to their supervisors stationed in Germany. The most challenging part was to be thorough. Their write-up needed to capture every single detail in the exact way that it happened. Their thoroughness relied heavily on viewing their video footage over and over again.

“One thing I find very helpful is to watch animal behavior from behind the lens,” Lara suggested.

“So, when something crazy is happening or when something uncomfortable is happening, if you just film, there’s always this wall between you and what you’re seeing, and you can always remember your place as just an observer. That was something that helped me in both of those instances to document what I was seeing rather than put my own opinions on what I was seeing.”

On December 11th, 2019, Lara and her group of researchers followed the chimpanzee patrol far north of their home range territory.

“Whenever we go up there, everyone gets a little bit grumpy because there are the big swamps. And when there are swamps, it means you have to swim.”

Walking towards the northern swamps, they could see the chimps begin to change their behavior. Once they got outside their territory, they became reticent, displaying similar behavior to the lethal February 6th event. They walked in single file, sniffed the ground, and smelled the eaten fruit near a tree, searching for the presence of rival chimpanzee groups. The chimp named Freddy was in front, near a female named Joy. He stood up bipedal to get a better look at something, reacting to what he saw with alarm barks.

“My initial reaction (because I had already seen them on patrolling behavior) is that they had found a chimpanzee group,” Lara remembered.

The chimps found a family of seven gorillas feeding high up in the trees. They climbed up to attack them, forcing the silverback to retreat, leaving the mother gorillas defenseless. The silverback’s role was to protect his family, but Lara defended the silverback’s decision to flee.

“It was a pretty hard decision in that case. There were seven gorillas against a group of 27 chimpanzees. Chimpanzees are very loud, they’re very vocal, and they cooperate. This is something we talk about in the paper. They’re very cohesive in terms of behavior when they feel like their group is threatened or when they’re going into doing a collective behavior. All of them participate.”

And this occasion was no different. Every chimpanzee joined the attack- even the juveniles were barking at full-grown adult gorillas.

“Which is something that I haven’t really seen before. So, in a sense, the silverback fleeing, I think, was also just a choice of personal safety. I think it was a hard choice to make.”

Several other gorillas had already fled, so only two females and two babies were left in the group. Lara speculated that the silverback might have been attempting to initiate the movement of the remaining members of his family by trying to get them to follow him. The other two females were left high up in the canopy with their babies, allowing the chimps to climb up the tree and trap them. The chimpanzees chased one of the mother gorillas through the trees across the swamp, cornered her, and snatched her baby. Roxy, the older adult female chimp, ripped out the baby gorilla’s intestines and ate them, snacking on its body for hours.

“Roxy played everyone’s least favorite role in the second encounter because she’s the one who ingested the baby gorilla. So, she kept the prey, and she carried it with her, and she fed on it as a piece of prey for most of the afternoon after they caught the gorilla.”

Click here to read part four of this exciting story, where researcher Lara Southern explains why these shocking events occurred.

Listen to the full Gorilla Project podcast episode where Lara Southern tells the story in her own words.