The larger the male gorilla, the better it should strike its chest to tell its friends and enemies how strong it is.
This was the result of a survey by German scientists that was published recently.
The researchers found that the sound of missile strikes was, as expected, a measure of size and force.
Females pay attention to the vibrancy with which males clap their hands on their chests when assessed as potential partners, while other male actors are a warning not to pursue a fight.
The researchers say it is a powerful communication medium in the dense rainforests where gorillas live.
Blows to the chest, by adult males, known as the “silver loin” due to the color of the hair on their backs, can be heard from a distance of over a kilometer.
“We assumed for a long time that it was kind of showing how strong they are, and they do this for both males and females,” said Edward Wright of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
For males, the message is: “Look, I’m old and strong, don’t mess with me,” and for women: “Look, I’m so old and strong, you might want to choose me as a partner.”
“For the first time, we can confirm that body size is transmitted through these bumps on the chest, which are a clear indication of body size.”
In the gorilla community, groups usually consist of one male and several females. Females can move between groups, and males compete for your attention.
When it comes to male gorillas, size matters. It means strength, fighting ability and reproductive success.
The “silver loin” uses strikes on the chest to alert male runners and align women to show size and strength.
Male gorillas learn to beat their chests at a young age, and they practice this skill as they grow.
Stronger and deeper
Research published in the scientific journal Scientific Reports, Shows that larger males make deeper sounds (lower frequency) when they hit the chest.
Hence, it is a clear sign of body size (in other words, a male gorilla cannot pretend).
The sounds are thought to be related to the size of the air sacs near the larynx, which are found in gorillas and some other great apes (but not in humans).
They participate in gorillas’ grunts and screams, as well as in a non-vocal breaststroke.
In addition, differences in the duration and number of blows to the chest by the different gorillas were observed, indicating that the extremities could be identified using only the strikes on the chest.