Saturday, October 26, 2024

Murder They Wrote: Chimpanzees Observed Killing Gorillas

Chimpanzees eating a small monkey they hunted (Source: © Liran Samuni, Tai Chimpanzee Project)

 

Thanks to the work of Jane Goodall and various other primatologists there is a great deal of information known about chimpanzees.  This research has demonstrated that chimpanzees are not just genetically related to humans but also display various behavioral traits that are commonly found among humans.  One of those is murder.  Acts of murder among chimpanzees have been critically evaluated, but it is clear that chimpanzees will and do murder there own for various reasons, including but not limited to infanticide, removal of tyrannical leadership, and protection of the group from outsiders.  Murder among chimpanzees is typically observed between non-related males (as both aggressors and victims).  Now there is a new dimension to chimpanzee behaviors, particularly when it comes to murder: chimpanzees murdering gorillas.

 

In February and December 2019 primatologists working in Loango National Park (in Gabon) observed two separate incidences wherein a large group (of almost 30) chimpanzees encountered and attacked a smaller group of gorillas.  These incidents occurred as a mixed group of young and old male and female chimpanzees were patrolling their territories.  The chimpanzees happened upon a group of gorillas wherein there was only one male, several females, and at least one infant.  Both times the attacks were initiated by the chimpanzees.

 

In the first attack the lone gorilla infant was the sole casualty of the skirmish. An adult chimpanzee managed to separate the infant from its mother and then hit it several times, leading to its death.  In the first attack the adult silverback (male gorilla) and several female gorillas rigorously defended their troop, leading to the injury of three chimpanzees.  In the second attack there was less defense occurring among the gorillas, who opted to run rather than stand their ground.  In the melee one of the two infants was separated from its mother (the circumstances of which are unclear since this occurred in the tree top canopy).  The infant was observed deceased, and it was ultimately eaten by at least two chimpanzees.

 

The primatologists were baffled by what they observed, particularly as chimpanzees and gorillas had never been seen involved in this level of conflict previously.  They had reportedly coexisted in this and other regions across Africa for decades without any serious conflict.  Upon reflection of the incidents the scholars concluded that the attacks may have been motivated by a reduction of food resources.  The chimpanzees and gorillas do have some overlap in food resources during specific times of the year, which happened to be when the attacks occurred.  Given the consumption of the second infant and the overlap in food resources it is suspected that the chimpanzees attacked because they were desperate for food. 

 

These attacks may have been random incidents, or they may be the beginning of a pattern that will continue.  If the chimpanzees attacked due to a fear of limited food resources the attacks could continue, particularly as human incursions on native non-human primate lands are the root cause of the lack of food resources for these creatures.  This underscores the reasons for why humans are a primary cause in nonhuman primate endangerment, even when there is no intention to do so.

 

References

Anderson, James R. 2018. Chimpanzees and death. Philosophical Transactions of the Royal Society B. 373: 20170257.

Luntz, S. (2021, July 21). Chimpanzees Seen Killing Gorillas For The First Time. Retrieved from IFLScience: https://www.iflscience.com/chimpanzees-seen-killing-gorillas-for-the-first-time-60411

Southern, L.M., Deschner, T. & Pika, S. Lethal coalitionary attacks of chimpanzees (Pan troglodytes troglodytes) on gorillas (Gorilla gorilla gorilla) in the wild. Sci Rep 11, 14673 (2021). https://doi.org/10.1038/s41598-021-93829-x

 

11 comments:

Ryota Haga said...

I read this text and was astounded by the details of the attack that occurred between the chimpanzee and the gorilla. It is particularly unexpected that such a violent clash would suddenly occur between two species that have supposedly coexisted peacefully. As the researchers point out, the decrease in food resources is the most likely cause of the attacks, which indicates that human-induced environmental destruction and land encroachment are having an impact. This fact reminds us once again that humans have a serious impact on other animals, even unintentionally. I strongly believe that protecting the habitat and food supply of animals is necessary to prevent further conflicts and the importance of sustainable environmental protection.

dayonna crump said...

I think using the word ''Murder'' is more over said. I say this because murder explains how humans view and understand what they see. I believe that the deadly acts between the chimpanzees and gorillas is strictly survival instincts rather than, the act of making a moral choice.
- Dayonna Crump

Danielle Adams said...

If they run out of resources in their wild habitats then they will migrate into lands with humans. Then they will get into homes of families and might have the same outcome as with the gorillas. Who's to say they will leave? They might just stay and everyone will have to vacate their homes and villages due to the animals and chimpanzees getting out of hand.
- Danielle Adams

Dr. Christine Elisabeth Boston said...

Danielle, as you should have learned from the course materials that outcome is highly unlikely. The reason: humans are the leading cause of the endangered of all nonhuman primates species, so even if chimpanzees were to attempt to harm humans chimpanzees would be exterminated.

Anonymous said...

Mauriah Taylor:

The fact that chimpanzees are acting so aggressively against gorillas is both cool to read on but also concerning because you would think that the gorillas would be acting out.The behaviors are unexpected knowing how long they have lived with one another. It shows how human activity has impacted their environment and food supplies, causing them to behave that way.

Jaden Brown said...

What I find interesting and this blogs oh it points out the many similarities between humans and chimpanzees, specifically when it comes to them being territorial

Anonymous said...

I found it interesting that the primatologists were surprised to see the conflict between the gorillas and chimpanzees because I had figured that different species of primates had often had conflicts with one another. I am surprised that primates often do not have conflicts between one another and I think that it shows how little the average person knows about primates. I hope that some day soon more people will gain an interest in learning about primates as I believe they are very interesting and there is still a lot we do not know about them.

Divyasheni Gunasegar said...

This blog shows surprising and worrying behavior in chimpanzees. The attacks on gorillas might be caused by lack of food, showing how competition for resources can lead to violence, even between species that usually live peacefully. It’s interesting how chimpanzee behavior can sometimes mirror human conflicts.

Anonymous said...

Jordan Hoskins

Murder They Wrote: Chimpanzees Observed Killing Gorillas
Murder? I think that is a little dramatic. Nature has its way of keeping balance. After reading this blog I was unaware that there was a conflict between gorillas and chimpanzees but it was somewhat expected because they are cousin species.
What took me by surprise is the frequency of these attacks.

francheska thompson said...

i think the word murder was not a right word for the article because some animals like the chimpanzee and us humans because we are related. we show emotion to things like murder and i di know that when other chimpanzees die they do show emotion too

Anonymous said...

This is a fascinating yet troubling look at the behavior of chimpanzees. It's surprising to learn that such violent interactions have occurred between species that typically coexist peacefully. The connection to food scarcity and human impact on their habitats adds an important layer to understanding these incidents. It's a reminder of how human actions ripple through ecosystems, affecting both animals and their behaviors.
Kayuuyor Okolo