The complex vocal cords of chimpanzees are highly efficient

Chimpanzees have an exceptional ability to make complex sounds. The team of scientists has identified nearly 400 unique sequences that describe a comprehensive communication system in this primate very close to humans.

“If they take human language for granted, they will not speak,” warns evolutionary biologist Cedric Girard-Bhutto, the lead author of a study published Monday in Natural Communication Biology. But chimpanzees have an exceptional ability to combine low-level cries and ‘twelve simple voices’ into at least 390 separate lines.

This kind of syntax, the meaning of which is to be clarified, is associated with two to ten cries. “We have some ideas about the meaning of certain rows, one of which, for example, is exclusively linked to nest building and has nothing to do with the meaning of calls taken in isolation,” the Institute’s CNRS researcher explained to AFP. Cognitive Science Mark Generot.

The team, along with some of its members, have partnered with the German Max Planck Institute for Evolutionary Anthropology to work on nearly 5,000 records made with 46 wild adult chimpanzees in the Ivory Reserve in Toy National Park.

‘Who’

The most common of the twelve types of chimpanzees’ voices includes the ‘hoo’, which is associated with or without suffocation, such as barking or barking. They are well known to experts and their significance can vary with severity. The ‘hou’ connected to the alarm cry is stronger and softer than the one connected to rest, ”says Mr. Girard-Bhutto. The ‘hoo’ associated with suffocation is used, for example, to identify individuals.

Some animals have a rich ‘vocabulary’, while ape species have 38 types of calls. ‘We can define the vocal cords of chimpanzees, they are innate, they are defined,’ said Mr. Girard-Bhutto mentions, but species with more complex social life may have found a way to ‘create new meanings’. It expands their communication ability.

The study shows that one-third of the voices are lines connecting several of the twelve calls, the whole range of which was used at one time or another. It also established the concept of a queue, with some calls always or almost always in the same position ‘pigram’, a queue connecting two calls. Some pictograms are reused, perhaps as keywords, in long lines, with five or six calls.

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