Caledonian crows can create tools from multiple pieces

An international team of scientists from the Max Planck Institute of Ornithology and the Oxford University has revealed that New Caledonian crows are able to create tools by combining two or more elements, if not nonfunctional, a capacity observed until here only in humans and great apes.

The new study, published today in Scientific reports, shows that these birds can create long-range tools from short combinable pieces – an incredible mental feat. The assembly of different components into new functional and manoeuvrable tools has until now been observed only in great apes, and anthropologists consider that the early manufacture of human compound tools is an important step in the evolution of the brain. Children take several years to create new tools, probably because it requires anticipating the properties of objects that are still invisible. Such anticipation or planning is generally interpreted as involving creative mental modeling and executive functions.

The study shows that this crow species has very flexible abilities that allow it to solve complex problems involving anticipation of the properties of objects that they have never seen before.

"The discovery is remarkable because the crows did not receive any help or training to make these combinations, they discovered them by themselves," said Auguste von Bayern, of the Max Institute. Planck for Ornithology and Oxford University. The Caledonian crows (Corvus moneduloides) of the South Pacific belong to the same species as Betty, who became famous in 2002 as the first animal capable of creating a hook tool by folding a soft material.

The researchers had already been able to show how this remarkable species could use and make tools in the wild and in captivity, but they had never seen them before combining more than one piece to make a tool.

Alex Kacelnik, of the Zoology Department of Oxford University, said: "The results obtained corroborate the fact that these crows possess extremely flexible abilities that allow them to quickly solve new problems, but do not show how they do it. It is possible that they use a form of virtual simulation of the problem, as if different potential actions were performed in their brain until they found a viable solution, then do it. Similar processes are modeled on artificial intelligences and implemented in physical robots, to better understand animals and discover ways to build machines capable of finding autonomous creative solutions to new problems. & # 39;

The researchers presented to eight crows from New Caledonia a puzzle box they had never met before, containing a small container of food behind a door leaving a narrow slot at the bottom. Initially, the scientists left sticks long enough scattered, and all the birds quickly picked one, inserted it in the front gap and pushed the food into an opening on the side of the box. The eight birds did it without any difficulty. In the next steps, the scientists left the food at the bottom of the box, but provided only small pieces, too short to reach the food. These short pieces could possibly be combined with each other because some were hollow and others could enter. In one example, they gave the birds barrels and pistons of hypodermic syringes disassembled. Without any help or demonstration, four of the crows partially inserted one piece into another and used the longer compound pole to reach and extract the food. At the end of the five-step survey, scientists made the task more difficult by providing even shorter, combinable pieces and found that a particular bird, "Mango", was able to make tools composed from three or even four parts.

Although the authors explain that the mental processes by which birds achieve their goals have not yet been fully established, the ability to invent a tool is interesting in itself. Few animals are able to make and use tools, and in human development, capacity only emerges late. As children begin to reliably use tools around the age of 18 months, they do not invent new tools that are suitable for the reliable resolution of a problem that occurs at the age of 18 months. at least five years old. Archaeological discoveries indicate that such composite tools only appeared late in human cultural evolution (probably about 300,000 years ago in the Middle Palaeolithic) and could have evolved with planning abilities, cognition, and language. complex. The ability of crows to build new composite tools does not mean that their cognitive mechanisms are equivalent to those of humans or great apes, but helps to understand the cognitive processes needed to solve physical problems.

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More information:
A. M. P. von Bayern et al. Construction of tools composed by Caledonian crows, Scientific reports (2018). DOI: 10.1038 / s41598-018-33458-z