THE marmoset (gender Callithrix), famous for their small size, the manes and feathers surrounding their small faces, and the trills that they make to communicate that resemble birdsong, have another unique quality that has recently been discovered. Some of these vocal signals, called by researchers callsare specific to identify and call out specific individuals in the community. In other words, they are the “first names‘ of each monkey.
This is a discovery of great importance, since this ability to vocally identify a specific individual has only been observed in humans, in addition to two other species with highly evolved brains and great social activity: the elephants and the dolphins. Even in primates closest to humans – chimpanzees, bonobos, gorillas or orangutans – this ability has not been identified.
According to researchers from David Omer’s lab at the Safra Center for Neuroscience at the Hebrew University of Jerusalem, who are publishing their work today in the journal ScienceThis ability to personally name individuals is a very advanced evolutionary trait. It is also an indication of the ability to establish functional and deep community relationships.
The scientists, led by researcher Guy Oren, recorded conversations between marmosets in their natural environment and between the monkeys and a computerized response system. In this way, they were able to determine that each of the different calls that they vocalize are addressed to a specific individual, and that the challenged monkey responds upon hearing his “name”.
“This discovery highlights the complexity of social communication in marmosets,” says Omer. “Their signals are not only used to locate each other, as previously believed, but they also use them to identify each member of the community and address them personally.” This could fulfill the evolutionary need to communicate in their habitat. tropical junglewith dense vegetation that limits visibility.
The study also found that members of marmoset families within the same group use vocal signals modulated in similar patterns to encode names, similar to a “dialect“among humans. This happens even among unrelated monkeys, which means that they “learn” the adult dialect when they pair up and become part of a new family.
THE callsThey would therefore be a way of maintaining social bonds and group cohesion while the marmosets are separated by the forest. “These monkeys live in small monogamous family groups and take care of their young together, like humans,” Omer continues. “These similarities suggest that they have faced evolutionary obstacles similar to ours. prelinguistic ancestorsand have been able to develop similar communication methods.”
This latter hypothesis would imply that the ability of marmosets to address each other with specific vocal signals is linked to the development of complex brain mechanismspotentially analogous to those that allowed humans to master language. It would therefore be a link in the evolution of social communication.
