First Lethal Attacks by Chimpanzees on Gorillas Observed in the Wild

Chimpanzee in the Wild

Research team now examines impact of food competition and climate change.

A research team from Osnabrück University and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has, for the first time, observed lethal attacks by chimpanzees on gorillas in the wild. Whether this behavior is due to competition for food or to the decline of the rainforest’s productivity caused by climate change will now be investigated in more detail.

Chimpanzees are common in East and Central Africa and live with gorillas in some areas such as the Loango National Park in Gabon. This park has also been home to the Loango Chimpanzee Project since 2005, led by Tobias Deschner, a primatologist at the Max Planck Institute for Evolutionary Anthropology, and Simone Pika, a cognitive biologist at Osnabrück University. In Loango, the researchers are observing and analyzing the behavior of around 45 chimpanzees with a special focus on group composition, social relationships, interactions with neighboring groups, hunting behavior, tool use, and communicative skills.

“Interactions between chimpanzees and gorillas have so far been considered as relatively relaxed,” says Simone Pika. “We have regularly observed both species interacting peacefully in foraging trees. Our colleagues from Congo even witnessed playful interactions between the two great ape species.”

Loango Chimpanzee Project in Gabon


Two adult males of the Rekambo community of the Loango Chimpanzee Project in Gabon checking the area. Credit: © LCP, Lara M. Southern

Lethal encounters between the chimpanzees and gorillas have so far never been documented. “Our observations provide the first evidence that the presence of chimpanzees can have a lethal impact on gorillas. We now want to investigate the factors triggering these surprisingly aggressive interactions,” says Tobias Deschner.

Encounter between chimpanzees and gorillas

What exactly happened? Lara M. Southern, PhD student and first author of the study, recalls the first observation in 2019: “At first, we only noticed screams of chimpanzees and thought we were observing a typical encounter between individuals of neighboring chimpanzee communities. But then, we heard chest beats, a display characteristic for gorillas, and realized that the chimpanzees had encountered a group of five gorillas.”

In the encounters, which lasted 52 and 79 minutes, the chimpanzees formed coalitions and attacked the gorillas. The two silverbacks of the two groups and the adult females defended themselves and their offspring. Both silverbacks and several adult females escaped, but two gorilla infants were separated from their mothers and were killed.

Adult Male Chimpanzee

Adult male chimpanzee in Loango National Park in Gabon. Credit: © LCP, Tobias Deschner

The authors from Osnabrück and Leipzig suggest several explanations for the interspecies violence observed including hunting and food competition between the species: “It could be that sharing of food resources by chimpanzees, gorillas and forest elephants in the Loango National Park results in increased competition and sometimes even in lethal interactions between the two great ape species,” says Tobias Deschner.

The increased food competition may also be caused by the more recent phenomenon of climate change and a collapse in fruit availability as observed in other tropical forests in Gabon.

“We are only at the beginning to understand the effects of competition on interactions between the two great ape species in Loango,” says Simone Pika. “Our study shows that there is still a lot to explore and discover about our closest living relatives, and that Loango National Park with its unique mosaic habitat is a unique place to do so.”

Reference: “Lethal coalitionary attacks of chimpanzees (Pan troglodytes troglodytes) on gorillas (Gorilla gorilla gorilla) in the wild” by Lara M. Southern, Tobias Deschner and Simone Pika, 19 July 2021, Scientific Reports.
DOI: 10.1038/s41598-021-93829-x

23 Comments on "First Lethal Attacks by Chimpanzees on Gorillas Observed in the Wild"

  1. Clyde Spencer | August 19, 2021 at 1:50 pm | Reply

    “Whether this behavior is due to competition for food or to the decline of the rainforest’s productivity caused by climate change will now be investigated in more detail.”

    The obligatory “climate change” got mentioned! They are apparently looking for grant money. Is there any supporting evidence of productivity decline in the area where the conflict occurred? I would think that, if there was a decline sufficient to trigger an unprecedented attack, it would be obvious. With an average global temperature increase of about 1 deg F in the last 50 years, with most of it at night and in the Winter, I wouldn’t expect a discernible change in the tropics.

    Gorillas are vegetarians and selective in what plants they eat, and what parts. We can probably rule out competition for food. An alternative hypothesis is that the chimps simply saw a potential opportunity to add protein to their diet, and were successful.

    https://gorillafacts.org/what-do-gorillas-eat/

  2. I agree with Mr. Spencer’s hypotheses. There is no food competition, wild chimpanzees studies have observed them always being aggressive killers, using guerilla warfare tactics to ambush and kill other gangs. Chimpanzees use this tactics to expand their territory as well as to hunt monkeys and other prey. I think if they want to keep the beautiful guerilla population healthy and alive, those in charge of the park should start by relocating a large amount of the male chimpanzees elsewhere or implementing a population control on them.

    • I advocate using stick and rock control to deprive the chimp’s of any weapons, thereby turning them into peaceful citizens of the jungle.

    • “… using guerilla warfare tactics …

      Strange choice of words to describe the behavior of chimp’s towards gorillas. Was it intentional?

  3. Actually, the apes’ violent interactions are relatively docile compared to their human cousins. And I bet none of the apes purposely destroyed their environments.

    • “And I bet none of the apes purposely destroyed their environments.”

      If they actually had the ability to do so, they probably would. Even humans are poor at visualizing what future impacts their actions will have.

      • The environment is fine, were in 3million yar old exponential climate trend, returning to base temp after the ice age, empirical evidence shows no correlation between climate acceleration, and increase in co2 over the same timeframe, with co2 trailing hundreds of years behind global temperature, that is because the sun is the main driver of climate, this has been empirically proven, the change in ice caps here is reflected on mars as well, meaning yes the globe is warming slowly, and naturally back to pre-ice age temps, and no we can’t stop it, you may as well try to stop a comet with your bare hands, the aluminum particulates being sprayed etc. All pointless bandages. Humans Total 35b tons of annual co2 or whatever is a mousefart compared tot total atmospheric volume, and even at today’s rate, not accounting for atmospheric scrubbing from plant life, algae etc, it would take a melinnia at maximum output to reach low toxicity, so CO2 based climate alarmism is just factually false, now factor in that over half of that will be scrubbed by nature, and factor in the fact that green technology is advancing at an exponential rate, and it’s clear CO2 isn’t a real problem. What is a problem is chemical contamination of waterways with dangerous chemicals like atrazine, and the plastics in ocean water. The former are because of irresponsible industry, and the latter are mostly from china africa and india. Given the above thre isn’t much we can do about foreign nations, but we should make sure our own waterways are free of industrial byproducts. That being said i will add at the end here that Smog is a real health issue for humans in particular so clean air in urban areas is an area of concern as well, and so i do advocate for green technologies, and clean manufacturing for that reason without consideration for CO2. Looking at LA and new york i particular they have very poor air quality. It wouldn’t be so much of a problem but because of the massive collections of skyscrapers creating an area that gets less airflow, it allows smog to collect in the area, thus particularly in thse areas emissions testing, and clean output for industry are a must.
        So im not anti-eco friendliness, but there is more to the story than the swindlers from the cocaine fueled scamming 80’s would have you believe, namely because it would get them paid, look at who benefits from the carbon tax scheme….

        • Sorry abt the typos, I’m on my tablet, and my sausage fingers don’t do well on touchscreens, though even if i weren’t, i crushed my left hand last summer in an accident, so my typing skills are ruined either way. But hopefully you understand what im saying here and don’t just think im some idiot that sucks at grammar.

  4. To be honest evolution never happened. All you elite evolutionist researchers have always been wasting your time. You’ve never proved a link between natural selection and species evolution. All you have ever done is to build upon one speculation after another. An uneducated person with common sense understands origins better.

  5. Steven Woodruff | August 23, 2021 at 10:02 pm | Reply

    In this eco system and with such small populations food resources can’t possibly be a problem. I worked in at a chimp sanctuary in Cameroun. The big male chimps were often very aggressive and violent even in a care facility where all their food and social needs are met.

  6. Marcus johnson | August 24, 2021 at 7:25 pm | Reply

    Do these folks ever stop making up crap
    I rarely believe anything
    u ha e to say …
    Maybe ur looking for more grants funding because of a false narrative 🤔

  7. Climate change? That’s their answer to all of the worlds’ problems? Climate change has existed since the beginning of time. What wasn’t here (yet) were greedy politicians and their corporate industrial complex. The climate change agenda is a huge hoax and THIS is where animals die. In their haste to bring the world to the “Great Reset”, the cabal, the elites, the useless eaters , whatever you want to call them are destroying forests around the world to use as firewood for their new green biomass generating plants. Hundreds of these biomass green generating plants have replaced coal burning plants. I don’t need to tell you that trees consume carbon dioxide produce oxygen. So we burn them depleting us of oxygen while producing carbon as they burn. Nice cycle.

  8. I recommend arming the gorillas as they are out numbered and that is not fair. Let’s introduce chimp an gorilla social groups to discuss the problem an at the same time encourage getting the shot. See this can all be worked out.

  9. So it’s not just in my hood ? I feel a little better

  10. This is an awesome site and the posts from people who actually seem intelligent. So often we the people just get information crammed down our throats and are forced to believe the climate change rhetoric and in the u.s especially. I try to explain to people if countries like china and ones in Africa had an EPA most likely lots of the things impacting our environment would probably be minimized greatly. That is if a communist country could actually allow itself to be held to some kind of standard, or have any kind of real concern about where their garbage goes and learn to recycle without creating other health concerns for their people. Funny how u.s Politicians think by making us change how we do our mfg and lives that we are going to save the planet. Wish they would go to China and push their views onto countries who don’t have standards in place already. Maybe then our gov inslee here in Washington state would really get what most of us want for him. Lol. Sorry that was mean. But really he will take jobs from our state for his campaign to save the world when we already have some of the strictest standards in the world. Move to china jay. And the guy posting about evolution. Most places if you posted that people would be attacking you like the chimps did with the gorillas, except worse most likely. But I guess in order to keep control they have to implement as much fear as possible. And nobody is ants you to believe God actually exists and there is more to life than just living and dieing. They sure like to believe in the devil, but don’t want you to believe in anything good except what they say is good. Hopefully this wasn’t to stupid sounding and thank you for reading.

  11. Oh! Climate chage so say. Let’s not mentioned in this column is the deforestation that has been going on for decades.

  12. Being territorial animals, especially with male Chimpanzee’s,with their environment becoming smaller,and food sources diminishing. I think they attacked for survival.

  13. You’re all idiots regardless. The best way to get the red nations to slow their incredibly high pollution rates, is by telling the most communicatively interconnected population that climate change will end humanity. If this helps slow them down and bring a scapegoat to bandwagon against, then the reason they’re shoving it down your throats is obvious. On a side note, we should be proud of ourselves because “habitants controlling the atmosphere of a planet(s)” climate graduates us into the next tier.

  14. Chimpanzees are just evil, that’s it, that’s all

  15. Since the gorilla is critically endangered, maybe it’s time to genetically engineer gorillas to be more aggressive so they can compete with other animals

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