We Knew Ravens Are Smart. But Not This Smart
The birds are surprisingly skilled at planning how to get food in the future, and will even trade for it.
We've long known ravens aren’t your typical bird brain: Myths featuring the wily black bird extend from Aesop’s fables to Native American folklore.
In more recent times, experiments testing the problem-solving capabilities of ravens and their corvid kin, the jays and magpies, have shown these birds have cognition on par with people and some other great apes. (Read how ravens hold grudges against cheaters.)
For instance, a trademark of being human is the flexibility to plan for future events, such as saving for retirement or figuring out a meal for the next morning. Scientists previously believed these behaviors were unique to hominids—humans and great apes—because no other animals, including monkeys, were thought to have such abstract thinking skills.
Now, a new study may challenge that long-held notion: Ravens are just as good as us at pre-planning tasks, according to animal cognition researchers Can Kabadayi and Mathias Osvath at Sweden's Lund University.
"I’m a little bit surprised they were that good," remarks Osvath, who has studied raven cognition for nearly a decade.
What's in the Box?
Kabadayi and Osvath designed a series of experiments with five captive birds to see if ravens can plan for an unseen future.
The basic experiment is as follows: The researchers taught the ravens that if the birds place a special tool in a tube sticking out of a box, it will release their favorite piece of food—one whole piece of dog kibble.
Then, the scientists took the box and the tool away.
An hour later, the team offered the ravens a choice of objects—one being that special tool. Fifteen minutes later, the ravens got the box back. ("Watch: A Clever Raven Outsmarts a Trash Can.")
About 80 percent of the time, the ravens selected the correct tool and performed the task to get their treat.
The team repeated the same experiment with a 17-hour delay in returning the box to the ravens. In this case, the birds were successful nearly 90 percent of the time, according to the study, published this week in the journal Science.
“Monkeys have not been able to solve tasks like this,” Osvath says, noting the birds are actually more skilled than human children.
In almost identical experiments on four-year-olds, the ravens were technically more successful in planning ahead to open the reward box than toddlers. (Related: "Are Crows Smarter Than Children?")
Tricks of the Trade
The researchers also set up an experiment to test the birds' bartering skills.
They instructed the ravens how to exchange tokens to get their favorite foods at a later time. Again, the birds passed these tests with flying colors over 90 percent of the time.
“It is really surprising to see ravens were better at solving two planning tasks than great apes and children presented with similar problems,” says Alex Taylor, an animal cognition expert University of Auckland in New Zealand who was not involved in the new study.
“This is particularly exciting given that the two behaviors, tool-use and bartering, are not behaviors that ravens display in the wild,” Taylor explains.
"This suggests that, like humans and great apes, ravens may have a general planning ability that can be used with novel behaviors." (Watch a video of a New Caledonian crow solving problems.)
Delayed Gratification
In the final experiments, the ravens could choose between an inferior immediate food reward (a smaller, less-tasty piece of kibble) and a token for their favorite kibble they could trade later—a concept called delayed gratification.
“Humans devalue things that take place in the future,” says Osvath, emphasizing people typically go for instant rewards.
Ravens seem to be a little more patient, selecting the tool or token that would get them the better food in the near future over 70 percent of the time.
However, Taylor notes that the results are open to interpretation. Perhaps, he says, they're outsmarting the experiment: “The ravens may not be thinking about the future at all, they may instead just be choosing the object the has been associated the most with food.” (Read “Minds of Their Own” in National Geographic magazine.)
Future experiments should be able to discern exactly how clever ravens are, but at the most basic level, these findings show that humans might not be as special as we thought.
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