Some non-human animal species display behaviors similar to mourning for the loss of friends or relatives.. It has been observed that elephants cover the corpses of their fellow-breeds with branches and soil, stay near motionless objects for days and move them with great care. as if they were watching. It has been widely observed in primates that chimpanzees also return to the place where they left their carcasses, and the mothers of this species carry their dead cubs for days, weeks, or months. But can they identify the skeletons of their own species? A team of scientists showed that Chimpanzees pay more attention to the skulls of their own species than to any inanimate objects in their environment..
“Chimpanzees and elephants share some interesting features; they are long-lived animals with a large brain and long-term development; living in complex societies they can recognize themselves in the mirrory taking care of injured and dead peers for a long time” collects the work. “Behavioral responses, such as physical handling of the corpse, seizures, and visits, are surprisingly similar between these two taxa,” he adds.
Until now, scientists had paid little attention to the possibility of some species being mortal. can identify the remains of dead congeners. One possibility is that chimpanzees – in this case – are admitted to have no knowledge of their anatomy.
A team from Kyoto University in Japan led by researcher André Gonçalves has confirmed the visual interest of specimens of this species in a series of images of specific and nonspecific skulls. And the results did not disappoint: chimpanzees once again surprised scientists.
Choice for faces
“The skulls of chimpanzees retain features and features similar to the faces of living specimens,” the researchers say. Thus, for example, general contours and The general arrangement of the eyes, nose, and teeth likely enables a network of brain regions to be activated. originally evolved to detect and manipulate the physiognomy of the face.
To test their hypothesis, Gonçalves and his team put faces, skulls, and stones in shapes similar to chimpanzee skulls and built a eye tracker to determine where chimpanzees stare and for how long.
The results, published in the Royal Society Open Science, show that Not only do chimpanzees most favor the faces of their fellows, they also exhibit a similar bias towards the skulls of these species.. It is the teeth that attract the most attention and observe for the longest time.
Research shows that chimpanzees seem to ‘know’ when a skull resembles one of its own species. According to scientists, this is probably because pareidoliaa psychological phenomenon linked to the brain’s ability to detect faces in objects or images.
“This explains why we see misleading faces in things like clouds and rocks. In this case, primate skulls look like faces like everything else in nature,” emphasizes Gonçalves.
While the research team wasn’t able to determine with certainty whether wild chimpanzees “know” that they’re holding the bones of another chimpanzee, they did find that they are more mindful than any inanimate object in their environment. And since they all “seem to be one of their own,” the scientist concludes.
elephant experiments
These findings are consistent with previous field experiments with African elephants. In 2006, Karen McComb, an expert in Animal Behavior and Cognition, and her team at the University of Sussex (UK) discovered: Thick-skinned people showed more interest in the skulls and teeth of their fellows than any other stimulant..
But the mechanisms may not be the same. Elephants likely interact with skulls, according to Gonçalves. past experiences. That’s because when organic matter dies and decomposes, the skulls of these large mammals lose many facial features important to their communication, such as ears and trunks. “In its place, chimpanzee skulls preserve the general facial pattern”, he concludes.
The experiment initially included 10 adult chimpanzees, which was later reduced to seven. For one of the tests, the scientists presented the chimpanzees with 180 images of four species (cat, chimpanzee, dog, and rat) displayed simultaneously in every corner of the screen. Each image set was presented for 6 seconds and gaze time was measured.
The result was clear: chimpanzees have shown a clear interest in the faces and skulls of their fellows, and even stones in the shape of chimpanzee skulls.. However they looked longer at faces, slightly less at skulls and much less at stones. And more front and diagonal views than side views. Moreover, chimpanzees stared at teeth longerthen towards the nose area and lesser eye areas.
“Probably the associative features that persist in the skull (facial contour, teeth, nasal cavity, eye sockets) face detection module It’s the area-specific that directs chimpanzees’ attention to these approximate facial features, experts say.
Reference report: https://royalsocietypublishing.org/doi/10.1098/rsos.210349