Orangutans speak of the past to their young | Science


If you remember the last conversation you've had, you probably talked about something past, or future, or someone who was not present. A capacity that does not even seem so, because humans do it with total naturalness in their day to day. However, the gift of referring to objects or situations far away in space or time was one of those Superpowers unique of the sapiens on the rest of the mammals. Until now, if the finding that has just arrived from the forests of Sumatra is confirmed: the orangutans are also able to tell their children about the past - and they understand it.

In the presence of a threatening tiger, the orangutan was silent and waited for him to leave to alert his offspring

The scientists subjected the Ketambe females to unexpected stress: the appearance of a tiger while hanging out with their young in the trees. Orangutans are quite asocial apes, so it is normal that they are alone with their offspring. In this context, the experiment hoped to register the warning cries of these orangutans, but they were disappointed. The (false) tiger appeared, stayed two minutes on the scene and vanished. But these mothers did not say anything. "We were surprised by his silence", recognizes the Barcelonan Josep Call, one of the authors of the finding, "but more than vocalize later". It is one of those discoveries with which it occurs when looking for something else.

What these mothers did to the threat of the tiger (a buddy of science covered with a blanket Animal Print like that of the image) was to remain silent, defecate and urinate from the tension, pick up the creature and begin to climb the branches stealthily. And when the beast disappeared, then yes, tell the offspring what had happened. "We know that these are vocalizations that they use in situations like this, for example, conflict, clearly demonstrating that they perceive it as a threat and yet they do not vocalize until they leave," explains Call, of the University of St. Andrews. , what publishes this study in Science Advances together with Adriano R. Lameira.

Aspect of the false tiger that the orangutans saw, a member of the team that was covered with a blanket with the feline pattern.
Aspect of the false tiger that the orangutans saw, a member of the team that was covered with a blanket with the feline pattern.

The scientists behind this discovery are cautious with their own results, but there are many striking elements in their work that support it. For example: among the 24 cases in which they experienced these scares with seven different females, there is a very clear correlation between the age of the offspring and what their mothers take in explain what happened. "If breeding does not matter, age would have no effect, but the warnings come much sooner the smaller it is," says Call. On average, it took 7 minutes to make those vocalizations (a kind of snapping noise), reaching 20 minutes with older pups and almost immediately with the smaller ones.

This psychologist reminds us that this is an "emotionally charged" situation and that is why older children are able to establish the connection between words of warning from the mother and what happened minutes before during the visit of the tiger: the mother defecates (which is a habitual response in situations of stress), she tensed, looked to a point, protected it, fled stealthily upwards .. "The key is what is the fundamental cause of this vocalization", warns Call, "and the data opens the door to this being the explanation".

"It has never been observed in natural communication or in wild animals, they do not communicate about something not present", highlights Call

This ability to speak of something that is not present is called a displaced reference and has been achieved in great apes such as chimpanzees raised in captivity, so that the intellectual capacity does. "In the laboratory it is achieved, but it has never been observed in natural communication or in wild animals, they do not communicate about something not present," the primatologist emphasizes. Years ago it was described, also in orangutans, a behavior that pointed in this direction: they could communicate where they would be tomorrow, before embarking on a trip.

Call accepts to speculate on what would be special in these orangutans so that they have this very human characteristic, the displaced reference, in front of chimpanzees, gorillas or bonobos. According to this expert, the orangutan spends a lot of time with the young, up to nine years old, and unlike what happens with other great apes, these offspring grow alone with their mothers. "The other apes learn with more members of the group, seeing and interacting with them, which provides more opportunities to learn, which in the case of orangutans are reduced," he explains. "If the mother does not react to such a situation, learning opportunities are reduced, so it would make sense that they had developed a more powerful, more sophisticated capacity for learning", Call's adventure.

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