Chimpanzees don't forget general

Laila had been there for twelve years. Reniver Primate Rescue Center. She was well adjusted and her behavior was perfect. Until one day, during one of the guided tours open to the public, she started to feel very nervous. It wasn't normal for her.

He says: “At the end of the tour, one of the visitors approached us and told us that he knew that chimpanzee, and that person was a friend of his previous owner, who had beaten Lily when she was young.” general Primate world Marta Bustillodirector of this monkey sanctuary, which is the largest in Spain.

Therefore, when studying published PNAS showed last month that chimpanzees are able to remember a person's face up to 25 years after they last saw them, and Bustillo wasn't surprised. “Laila was not only able to recognize the person who He mistreated her“But also for people in their social environment.”

“It's very clear to us that the great apes They know how to distinguish facial featuresNot only among themselves, but with people. “But until academic research like this comes out, it's just another story,” says Marta Bustillo, who has been working with primates for 29 years.

They get to know their peers and people

Their ability to maintain long-term memory may have been a key factor in the evolution of their species

“Just as it happens to us, Primates recognize people Not only because of his face, but also because of the way he walks. “Even, as other research has shown, even if he covers his face,” Bustillo says.

This was proven by Louise, a 46-year-old dwarf chimpanzee who participated in the doctor's experiment. Laura Lewisan evolutionary psychologist at the University of California at Berkeley and author of a study that records how a number of chimpanzees and pygmy chimpanzees They remember the faces of other monkeys Which they haven't seen in years.

Louise lived until 1992 at the San Diego Zoo with her sister and cousin. He then parted ways with them when he moved to the Cincinnati Zoo, and in 2014, To Kumamoto Shrine, in Japan. Well, after all this time, 26 years, he was still able to unambiguously identify his relatives.

His ability to have long-term memory would have been a A key piece in evolution One of his kind, according to Lewis. In their opinion, this could be useful to them in their life in the wild: for example, when a female pygmy chimpanzee frees herself from her mother to join another group, and in the future, the two groups meet again, her ability to remember helps her. Serves for Establish alliances with family Or acquaintances.

The trial began with the installation of a screen in a 26-animal enclosure at Edinburgh Zoo Scotland; Kumamoto Shrine Japan; And Blankendale Zoo, in Belgium. To make sure they got close enough, the researchers placed a straw next to the screen, from which the chimpanzees could sip their favorite juice.

So, They were shown pairs of pictures – for three seconds each – from the other monkeys, one of whom was an old companion the chimpanzee had not seen in years, and the other a stranger.

They suffer a lot from captivity

Monkeys suffer trauma and psychological problems due to abusive situations

Using an infrared camera, scientists were able to capture their eye movements and discovered that these primates They spent more time looking at their old friends – Whether they are relatives or not – from strangers.

This ability to Remember long term It is another characteristic that humans share with apes and with other species, such as dolphins, which can remember their mates after being apart for twenty years, according to others. studies-.

The same is true with humans and apes Exposure to trauma and psychological problems Because of the situations of abuse she was exposed to, like what happened with Lily who came from exploitation in the entertainment world. “They are animals They suffer a lot from captivity“They are fully aware that they are deprived of their freedom,” says Marta Bustillo.