The dazzling intelligence of corvids — the family that includes ravens and crows — is well-documented. Studies have suggested that corvids rival chimps in cognitive self-control. Ravens can imagine being spied on, and crows display puzzle-solving skills comparable to those of apes and human children.
Research published Friday in the journal Science adds even more evidence to the pile. Scientists from Sweden’s Lund University found that ravens appear to have the ability to plan for the future.
Cognitive zoologist Mathias Osvath and graduate student Can Kabadayi presented five ravens with a series of puzzles. First, they taught the birds how to get a food treat out of a puzzle box using a specific tool. The ravens also got the opportunity to interact with the puzzle box with no tools, and with objects that would not open it.
They then presented the birds ― with no puzzle box visible ― an array of options, including the functional tool and a bunch of useless “distractor” objects. The puzzle box was installed 15 minutes later. The birds successfully selected the tool and used it to open the box 86 percent of the time, excluding one particularly resourceful female who figured out a way to open the box all by herself, with no tool.
A similar experiment involved teaching the ravens to use a token to “barter” with humans for a food reward. (Basically, the ravens gave the token to a person, and the person gave them a treat in return.) Again, the ravens were largely able to correctly select the token for future use when presented with a range of objects.
The ravens also demonstrated self-control skills: They were willing to forgo a reward in lieu of a better reward they had been trained to know would come 15 minutes later. Researchers presented the birds with a range of objects that included distractor objects, the useful tool or token, and a food treat. The treat was “less valuable” ― it’s not specified what this means, but presumably it was smaller and/or a food that ravens like less ― than the treat that ravens could later obtain by using the tool or token. (In control versions where no tool or token was available, the birds picked the immediate treat 100 percent of the time.)
Kabadayi told NPR that the birds — like humans — were less likely to delay gratification when they knew it would take longer to get a larger reward.
“We basically found that the further ahead in the future a reward for ravens, the less value it gets,” he said.
The researchers note in their paper that the ravens’ performance bore “conspicuous similarities” to the abilities of great apes in similar tasks.
Markus Boeckle, a psychology professor at the University of Cambridge unaffiliated with the study, expressed excitement over the research in an interview with Scientific American, but had some reservations. For instance, he noted that the small sample size of five hand-raised ravens might not be representative of the species as a whole.
For all we know, he told the site, those birds could be “the Albert Einsteins [of] the raven world.”