Ravens Can Make Plans for the Future, in Some Ways Surpassing Apes

Ravens can plan for the future as well as great apes, research shows. Andy Clark / REUTERS

Ravens, crows and their relatives are incredibly smart. They have complex social lives; can remember human faces for a long time; understand cause and effect; and intuit the properties of water displacement as well as human children.

New research suggests that they can also plan for the future as well as great apes, an ability once thought to be uniquely human. Quoth the raven: Nevermore.

In a study published in the journal Science, researchers Can Kabadayi and Mathias Osvath from Sweden's Lund University gave ravens a battery of tests that have also been administered to great apes to prove that they have long-term planning abilities. In one of the tasks, the birds were given a tool that could be used to open a puzzle box that had a food reward within. The box was taken away for an hour and then returned, but with several "distractor" tools. Most of the ravens chose the correct tool to open the box, which was again taken away and returned 15 minutes later. Nearly 90 perecnt were able to open it, having snagged the right tool. A similarly high success rate, at around 80 percent, was seen in another task where ravens used a token to later barter with a human researcher for a reward.

The ravens were as good with tools as apes, and in some ways better at bartering, outperforming orangutans, bonobos and chimpanzees, according to the study.

In 2006, researchers showed that ravens could plan ahead—to hide food in a specific area the night prior, and access it the next morning for breakfast. But there has been debate about whether those findings showed the animals could indeed plan ahead; Other animals that aren't thought to be able to plan for the future, like squirrels, also cache food. The strength of this study is that it involved activities, such as tool use and bartering, which don't take place in the wild, Osvath says.

The evolutionary paths of primates and the crow family (which includes ravens, crows and jays and is known as Corvidae) diverged about 320 million years ago. This suggests to the researchers that corvids developed their cognitive abilities independently from primates. Thus, the study of ravens, crows and their ilk offers a fascinating opportunity to better understand the nature and evolution of cognition, planning and perhaps even consciousness, Osvath adds.

As we spoke, I heard the sound of an assertive bird in the background. Is that a raven? I ask. "Yes, it's a raven," Osvath says, noting that he is standing outside. "She was released three years ago, but she hasn't left." In the course of raising the birds for research, the scientists sometimes release young that are raised by ravens. But some of them decide to stick around and sneak bits of food from humans.

Osvath says that above all, ravens are playful, and in interacting with them, one gets a sense of each individual's different personality and intelligence. Ravens, crows and other corvids have been companions to humans since the beginning of human history, and many legends tell of their special abilities. One of these is their ability to see ahead. This study suggests there may be some scientific basis to the idea.

"This is new, very exciting evidence which we didn't have before," Markus Boeckle at the University of Cambridge, who wasn't involved in the study, tells New Scientist. "[It's evidence] that general intelligence has also developed in birds. This is very important for understanding how intelligence evolves."