Ravens can be better at planning ahead than four-year-old children, study finds

One bird outsmarted the scientists by inventing her own way of accessing a reward inside a box and was therefore excluded from further tests

A raven sits on the carcass of a roe deer (Reuters)

Ravens are better at planning ahead in certain situations than four-year-old children, orang utans and chimpanzees, according to a new study.

While the birds, members of the crow family, are known to hide food for later consumption, there was a theory that this was not so much a sign of general intelligence but a highly specific, learned behaviour.

Only humans and the great apes were thought capable of genuine forward planning.

However, a new paper published in the leading journal Science described how the birds were easily able to pick out tools for later use and could barter with humans, exchanging a token for a future reward.

They also exercised considerable self-control, avoiding lesser rewards in order to receive a better one – even if it came the following day.

The researchers, from Lund University in Sweden, wrote: “This study suggests that ravens make decisions for futures outside their current sensory contexts.”

Ravens were deemed to have an ability to plan ahead in life generally – not just when it comes to hiding food – “on a par with apes”.

“In the bartering conditions, the ravens outperformed orangutans, bonobos, and particularly chimpanzees,” the paper said.

When presented with a task for the first time – seen as a greater test of intelligence, rather than habit – the ravens performed “better than four-year-old children in a comparable set-up”, it added.

“Ravens are avian dinosaurs that shared an ancestor with mammals around 320 million years ago,” the researchers concluded.

“The conspicuous similarities in performance to great apes in tasks such as these opens up avenues for investigation into the evolutionary principles of cognition and shows what the brains of some birds are capable of.”

The study involved five birds, three females, called Juno, None and Embla, and two males, Rickard and Siden.

In one test, the birds were taught how to open a box with a tool. They were then presented with the box but not the tool. It was then taken away and the birds were shown the tool and several other “distractors”.

Nearly all of the ravens picked the correct tool in anticipation of the return of the box. When this happened, they successfully used the tool to open the box in 86 per cent of the tests.

Somewhat comically, one of the females appears to have outsmarted the scientists.

“In trial nine, one female invented a way to open the apparatus without the tool (and was therefore excluded from subsequent tool conditions in the rest of the study),” the paper recorded.

In the bartering test, the ravens picked out a token that could be used later to exchange for a reward with a 78 per cent success rate.

They also demonstrated self-control when given the chance to select an immediate reward or a tool to open a box containing a better reward sometime later, preferring the latter.