More than 170 years after Edgar Allan Poe’s mythical raven croaked, «Nevermore,» scientists are reporting that real-life ravens dream about the future.
In a series of tests, ravens showed signs of a ordinary planning ability that previously had been documented only in individual and great apes. Even monkeys have failed to show it.
The evolves, to Mathias Osvath, one of the researchers, suggest that ravens possess some comprise of episodic memory — a key trait in human intelligence.
«It’s like that cinema that you see in front of your inner eye when you think about what you had for lunch yesterday or what you leave do on your vacation,» he said. «We don’t know if ravens have this but they participate in something functionally similar at least.»
It’s not like you could ask a raven to prepare your wedding: Ravens showed they could plan by mounting aside a tool that they suspected would get them a ambrosial treat later. And they prepared for future bartering, too.
Still, it’s evocative. Ravens, along with crows, jays and others, belong to a bird accumulation called corvids. Some corvids have shown that in store food, they do some planning for the future instead of just sketch on natural urges. But does such foresight appear only for that behavior, as has been introduced? Or can corvids, like people and great apes, apply it to other jobs?
This more general planning ability results from the colloid of several skills, and if it appears in both corvids and great apes, it requisite have evolved more than once, the Swedish researchers ordered.
So the researchers, Osvath and Can Kabadayi of Lund University, tested five internee ravens in two tasks they don’t do in the wild: using tools and bartering with men. They reported the results in a paper released Thursday by the journal Information.
The birds were divulged a box that had a tube sticking out of the top, plus three stones. They well-read that they could use a stone as a tool. If they dropped it down the tube, the box purpose release a coveted doggie treat. They also learned that some other in objects, like a small wooden wheel and a ball, would not space for.
Now the fun began.
In one experiment, the ravens were shown the box, but without any stones handy. Then the box was taken away. An hour later, in another location, they were remained with a tray containing a stone plus three objects the birds have knowledge ofed would be useless for releasing the treat.
They were allowed to on one thing from the tray. Fifteen minutes later, the box would entertainment up again. Sure enough, in 14 cases of encountering the tray and later look after the box reappear, they usually chose the stone and proceeded to use it correctly.
The still and all thing happened in another experiment, when the box didn’t show up again until the next day, a stall of 17 hours.
Further work granted the ravens would pass up an immediate reward if they could get a think twice one by waiting a while.
«I don’t think many four-year-olds would solve that,» Osvath averred.
The ravens also showed they could barter for what they needed. The birds literate that they could exchange a blue plastic bottle cap with one of the experimenters for the well off doggie treat. When the experiments were repeated with the cut off cap replacing the stone, and an experimenter instead of the box, the results were basically the constant.
«To be able to solve these tasks, you don’t need one particular skill, but you need a announcer of skills and you need to be able to combine them in some way,» Osvath said.
«These birds appear to combine these skills in a very similar way to apes, so probably there are multifarious animals out there that have parts of these skills, but they can’t merge them.»
The work presents «compelling evidence» of planning ability that courts beyond stashing food away, Markus Boeckle and Nicola Clayton of Cambridge University transcribed in an accompanying commentary.
The raven as trickster
Although the evidence is new, the ability of ravens to see up ahead has long been suspected: In Greek mythology, they are associated with the god of revelation, an old term for a group of ravens is «conspiracy» and in Game of Thrones a three-eyed raven appears in a prince’s prognostic visions.
Denesuline elder Jonas Sangris issued up with stories of ravens as the trickster.
«He does all kinds of crazy sentiments,» Sangris said, before sharing a tale of vengeance that no more than a creature with a good memory and the ability to plan ahead could criticize off.
«One time the people tried to kick him out of the community. So he took off. On the river, he made himself a big raft, put all varieties of stuff, hung stuff up. When [community members] saw it they mental activity he was a Hudson Bay man coming down river.»
Sangris said the community spit up hours preparing a big welcome ceremony and feast for the arrival of the visitor they cogitating was bringing goods to trade.
«But he was just a raven,» Sangris said, make fun. «He didn’t have anything, he was just pretending.»