Just Like Humans: Ravens Plan for the Future

Just Like Humans: Ravens Plan for the Future

The study, published yesterday in Science, shows that ravens (Corvus corax) can anticipate the nature, time and location of future events based on prior experiences.

What's more, the researchers think corvids evolved their forward-thinking abilities all on their own: They haven't shared a common ancestor with great apes for more than 300 million years.

Why would ravens develop the ability to plan? That is, until Osvath designed a test similar to the one he presented to the ravens to see if other primates are able to plan.

Here, Can Kabadayi and colleagues sought to further explore the ability of ravens to plan ahead through a series of experiments.

The researchers wanted to see if five ravens could plan while doing tasks that they don't normally do in the wild, specifically using tools and bartering.

"There was no real proof that [ravens] actually can transfer a cognitive ability in future planning to other behaviors".

Juno the raven working the puzzle box. The box was removed and one hour later the ravens were given the opening tool, as well as several "distractors".

As we spoke, I heard the sound of an assertive bird in the background.

Finally, the ravens were presented with the correct, apparatus-opening tool, distractor tools, and an immediate food reward, but were only permitted to select one item. For the experiment, the ravens were trained to pick a token out of a group of objects, then hold onto the token for fifteen minutes before exchanging it for a treat, reports Anil Ananthaswamy at New Scientist. Fascinatingly, the ravens performed better in the bartering tests than orangutans, bonobos and chimps, as shown in other studies.

Though the birds had no knowledge of whether the kibble box would return or not, the ravens chose the box-unlocking stone from the tray in 86 percent of the tests. They were able to complete the task better than four-year-old children. Importantly, the immediate reward was not as good as the reward inside the puzzle box, and the ravens knew it. As the researchers report, the ravens selected the tool, demonstrating a level of self-control comparable with that seen in great apes. To avoid going hungry, these brainy birds store specific types of food in places where it isn't readily available.

Alice Auersperg, a behavioural and cognitive scientist at Vienna's University of Veterinary Medicine (also not involved in the study), was likewise impressed with the study. "Impulse control is an important aspect of planning".

"I'm pretty impressed by the levels they showed - the levels of success in all experiments", says Osvath. They learned that they could use a stone as a tool. They did so by having them use tools and forcing them to barter. When the delay was extended to 17 hours, the ravens picked the right tool 89 percent of the time. But some of them decide to stick around and sneak bits of food from humans.

Taylor says this is the key control - divorcing the token from food association - that's missing from the study.

The simplest assumption in evolution is that all species that share a trait share an evolutionary history, and that the trait emerged at the beginning of that evolutionary history. That points to a complex evolutionary story.