Do you use your hands when you speak?
I definitely do that, but even if you don’t, you do sometimes use gestures to communicate – to ask someone to pass you something, to wave someone to come closer or to apologise. Small children hold their arms out when they want their parent to pick them up. We employ many gestures to communicate without speaking.
It turns out that we share this ability with our close relatives, the great apes.
African great apes (gorillas, chimpanzees and bonobos) live in groups, mainly on the ground, and like us use their hands and arms to communicate in many situations. But Asian great apes (orangutans) have a different lifestyle. They spend a lot of time in the trees and they are in principle solitary. They meet to mate, but their main social interaction is between mothers and their young children.
But even though orangutans have limited contact with other individuals of their species, they can exhibit a broad range of communication, both vocally, through facial expressions and with gestures. Recently researchers recorded and described communication using gestures between wild orangutan mothers and their young for the first time.
Both mothers and young use multiple gestures, like beckoning with their hand (or foot), extending their open hand, swinging their arms or legs or stamping their feet. Sometimes a gesture includes touch – like a poke, push or grab.
Many gestures can have different meaning depending on the situation. The goals can include “give me that”, “let me climb on you”, “move away”, “stop that” and others. And different goals can be achieved with multiple signals.
Even though sometimes gestures had to be repeated multiple times to get a reaction, in principle orangutan mothers and children are very responsive to each other’s gestures. The long time a child spends with their mother is probably an important factor in developing efficient communication.
Animals gesture more often when they are close to each other (within a meter) and when the recipient is actually looking at the signaller. If the recipient is busy or looking in a different direction, but is nearby, the signaller will add touch to communicate something.
It seems that some gestures are age-specific. For example, only mothers pushed or beckoned. But only young reached with open palm or hit the ground or stamped their feet.
Although orangutans usually used their hands to gesture, they used their feet more often than other great apes and they also sometimes gestured with both hands and feet. This could stem from the fact that their legs and feet are longer and more flexible and they use them both a lot when moving in tree crowns.
The researchers conclude that “ape gesture communication remains distinct, with exception of human language, in the scope and flexibility of the signals and their meanings”.
Unfortunately, all three species of orangutans are critically endangered, mainly due to habitat loss. A major reason is the conversion of tropical forests to palm oil plantations as palm oil is added to many processed foods in your supermarket.
You can check the examples of recorded gestures here.
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Photo: e-smile from Pixaby