This article is from WeChat official account:Academic Jingwei (ID: Global_Academia)< span class = "text-remarks">, author: WuXi PharmaTech content team title figure from: Dian Fossey Gorilla Fund
If you were asked to imitate a gorilla, what would you do? A typical action is to quickly tap the chest with two hands in turn, making a bang-bang-bang drum sound.
That’s it:
▲Silverback Gorilla Beating the Chest (Picture Source: Dian Fossey Gorilla Foundation)
The image of a male gorilla beating his chest with his hands is deeply rooted in the hearts of the people. But why do they like to beat their chests? People speculate that this is for the exchange of certain information, but no one knows the exact answer to what information is being conveyed.
Now, the wild mountain gorilla (Gorilla beringei beringei) in the Rwanda Volcanoes National Park confided to scientists the secret of their chest beating.
This research was published in “Scientific Reports” (Scientific Reports) under “Nature”, which was developed by German Max Planck. Headed by Dr. Edward Wright of (Max Planck Institute for Evolutionary Anthropology).
▲Dr. Edward Wright observing the gorilla (Picture source: Max-Planck-Gesellschaft official website)
From January 2014 to July 2016, researchers observed that the Dian Fossey Gorilla Foundation (Dian Fossey Gorilla Fund International)25 wild male silverback gorillas under supervision, recorded more than 500 chest-beating events.
They recorded the chest-beating sounds of six of the gorillas, measuring the rhythm and duration of each chest-beating of different gorillas, and the frequency of the chest-beating sounds. At the same time, they used photos to measure the shoulder width of these gorillas to determine the size of different gorillas.
▲A male gorilla is hitting the chest (Image source: Jordi Galbany, Dian Fossey Gorilla Foundation)
After analyzing these measurement data, they found that “mountain gorillas can reliably convey body shape information by beating their chests“. Specifically, larger males continue to make lower-frequency sounds when they beat their chests. Researchers speculate that this may be related to the larger resonance cavity of their bodies.
Researchers also noticed that males beat their chests more frequently during estrus of female gorillas, so the sound of chest beats may be an important body display during courtship. Attract females on the one hand and scare rivals on the other. /strong>.
Interestingly, the chest beat rhythm and duration of these gorillas has nothing to do with body size, and it is not that the bigger the body, the longer the beat. The chest beat rhythm of each gorilla is more like a personality label, and the duration and number of times vary from “orangutan”. Researchers analyzed that personalized beats can allow other gorillas to distinguish who is beating their chest.
▲A gorilla hits the chest while interacting in small groups (Photo source: Dian Fossey Gorilla Foundation)
The scientists finally concluded that mountain gorillas live in dense tropical forests, and sometimes they cannot see each other even if they are very close, but beating their chests conveys important individual information for them to communicate with each other.
Reference materials
[1] Edward Wright et al., (2021) Chest beats as an honest signal of body size in male mountain gorillas (Gorilla beringei beringei) Scientific Reports. DOI: 10.1038/ s41598-021-86261-8
This article is from WeChat official account:Academic Jingwei (ID: Global_Academia)< span class = "text-remarks">, author: WuXi content team