Register for the Wonder Theory Science newsletter from CNN. Explore the universe with news on fascinating discoveries, scientific progress and more.
Cnn
–
At the beginning, the behavioral ecologist Zoë Goldsborough thought that the small silhouette seen in the back of a Capuchin monkey in his camera trap images was only a baby nasturtium. But something, she said, seemed to be extinct. A more in -depth look gave the unexpected coloring of the figure. She quickly sent a screenshot to her research collaborators. They were perplexed.
“I realized that it was really something that we had never seen before,” said Goldsborough.
A new observation of the video and a cross -check among the researchers revealed that the little figure was actually a monkey of a different species – a baby howler.
“I was shocked,” said Goldsborough.
While Goldsborough was rummaging through the rest of her images, she noticed the same adult monkey – a white -face nickname nicknamed “Joker” for the scar on her mouth – carrying a baby howler monkey in other clips. Then, she noticed other male nasturtiums, scientifically known as CapuCinus imitator Cebus, doing the same thing. But why?
Using 15 months of camera sequences of their research site on the island of Jicarón, a small island of 55 kilometers (34 miles) off Côtes du Panama and part of the Coiba National Park, Goldsborough collaborators of the Max Planck tropical research institute, studied the strange behavior to find a response.
They noted that, starting with Joker, four monkeys of subsbone capuchins and juvenile males had removed at least 11 yeast monkeys for infants between January 2022 and March 2023. Without any evidence of the eating, taking care or playing with infants, the authors of the study suspect that the removal behavior is a type of “fad cultural”. They reported their first conclusions on Monday in the newspaper Current biology.
However, many questions remain. And untangling the mystery could be crucial, the researchers said. The Hurleux population on Jicarón is a subspecies in the process of disappearing failed howrs, Alouatta Palliata Coibensis, according to the IUCN red list of endangered speciesA global evaluation of the vulnerability of species to extinction. In addition, the mothers howl Monkey only give birth once every two years, on average.
The examination of the case of Kidnapper Capuchin “was a bit like a Russian mountain where we continued to have different interpretations, then we would find something that turned out to be bad,” said Goldsborough, the main study of the study and a doctoral student at the Max Planck Institute of Animal Behavior and at the University of Konstanz.
The island of Jicarón is uninhabited by humans. Without electricity and rocky terrain, scientists must transport their equipment and other materials on the island with boats when the tides are good, which makes observations in person tightly observations. This is why they use camera traps: hidden cameras and triggered by the movement that capture photos and videos of tight capuchins.
But there is a major limitation to their work: you do not know what you cannot see, and the traps of the camera do not capture what is happening in the treetops, where the howlers’ monkeys live. Thus, the study team could not definitively confirm how, when or why the Capuchins removed babies.
At first, researchers thought it was a case of rare and punctual adoption. The monkeys are known to “adopt” abandoned infants of the same species or others. But Joker did not take care of the howlers – he transported them just on his back, without any clear advantage for himself, until the infants finally perished famine without access to breast milk.
It is a strange behavior for male primates, said Pedro Dias, a primatologist at Veracruzana University in Mexico who studies the howled monkeys managed by Mexico and was not involved in research. In primatology, it is quite common to find women adopting or removing infants and then taking care of them as a maternal instinct, he said. But on Jicarón, the males did not provide maternal care.
When the behavioral environmentalist Corinna first read the kidnappings of Jicarón Monkey, she suspected that something else was going on. “They probably eat these babies,” mostly said an assistant assistant teacher at the Iowa State University who studies his baboons, his first thoughts.
The removal for predation is not uncommon in the animal world, added most, which was not involved in research. But as she learned more about the team’s observations, she was surprised to see that this did not happen in this case either.
Instead, the Capuchins totaled the baby howlers for a few days with little interactions – no game, minimum assault and little interest. The reason why they would exercise energy to steal babies is not clear, said the co-author of the Brendan Barrett study, behavioral ecologist and Goldsborough advisor.
However, it is important to note that these island Capuchins have evolved in a different environment from their continental parents, explained Barrett. The Capuchins are “exploratory agents destructive of chaos,” he said. Even on the continent, they tear things up, hit the wasp nests, struggle with each other, harass other species and search just to see what is happening.
On an island without predators, “it makes it less risky to do stupid things,” said Barrett. Capuchins of the island can also spread because they do not need a number in number for protection, which allows them to explore.
With this relative security and freedom, the Capuchin monkeys of Jicarón could be a little bored, proposed the researchers.
It turns out that boredom could be a key engine of innovation – in particular on the islands, and in particular in young individuals of a species. This idea is at the center of the Goldsborough thesis research On the Capuchins of Jicarón and Coibathe only monkey populations in these areas that have been observed Use of stones as tools for breaking the nuts. In accordance with kidnappings, it is Only males Who uses tools on Jicarón, which remains a mystery for researchers.
“We know that cultural innovation, in several cases, is linked to the youngest and not the older ones,” said Dias.
For example, proofs of potato washing behavior in macaques on Koshima Japan Island were First observed In a young woman nicknamed Omi.
There are some possible reasons for this, said Dias. Adolescence is a period during which primates are independent of their mother, when they start to eat and explore by themselves. At this stage, the monkeys are also not entirely integrated into the society of their group.
Over -imitation – A trend in human children to imitate the behavior of others even if they do not understand it – could also be at stake, most of them said.
This over-imitation is not found in other animals, most of them underlined, but “I have almost the impression that this is what these other Capuchins do”, perhaps as a means of binding socially with Joker, she observed.
Most have said that she generally thought that necessity, rather than free time, is the mother of invention in nature. But “this document makes a good case for (the idea that) perhaps sometimes animals that are really intelligent, like the Capuchins, are bored,” she noted.
People and other primates share a certain level of intelligence defined by the use of tools and other measures, but certain shared features could be less desirable, said Goldsborough.
“One of the ways we are different from many animals is that we have a lot of these types of arbitrary and almost without function that really harm other animals,” she added.
As a child who grew in the northeast of the United States, Barrett said he used to catch frogs and lightning insects in mason pots while exploring outdoor. Although he never wanted to harm them, he knows that these activities are generally not pleasant for the animal.
It is possible that the abduction behavior of the Capuchins is also arbitrary – if not moderately entertaining for them. Barrett and Goldsborough said that they hoped that this new behavior disappears, much like the modes among humans come and go. Or maybe the howlers will grasp what is going on and adapt their behavior to better protect their babies, added Goldsborough.
“It is in a way like a mirror that is reflected in ourselves,” said Barrett, “to do us apparently things to other species that can hurt them and seem excruciating that have no real goal.”