Ravens can plan ahead like humans: Study

London: Ravens can plan for different types of future events and demonstrate human-like skills such as self-control and sensitivity to different lengths of time, a study has found.

Researchers from Lund University in Sweden let ravens solve tasks that they do not encounter in the wild, and hence lack specific adaptations for: tool use, and bartering with humans.

They found that over several experiments, the birds could select either a tool or a token from among a set of objects to solve a future problem in another location.

The tool allowed the birds to retrieve a reward from a box, and the token could be given to a human in exchange for a reward.

The delay between the item selection and the task ranged from 15 minutes to 17 hours depending on the experiment.

The ravens planned for bartering more accurately than apes, and were on par with them in the tool-using tasks, despite that they lack predispositions for tool handling.

Researchers also tested the ravens' self-control by including a small piece of food among the objects they could choose from, including the tools and tokens, and then varying the amount of time between the choice and the task.

"It is a well-known psychological mechanism in humans that time devalues reward; the longer we have to wait, the less it will be worth," said Mathias Osvath, Associate Professor at Lund University.

In other words, the ravens should exert self-control by selecting the tool or token more often when they believe the opportunity to use it will be closer in time, researchers said.

This is exactly what they did, suggesting that ravens took the time delay into consideration when choosing. Overall their level of self-control is similar to that of the great apes, they said.

To be able to solve tasks like these, one needs a collection of cognitive abilities working in concert, such as inhibitory skills and different forms of memory, Osvath said

"That ravens show similar functions, and combine them in ways similar to apes, despite a last common ancestor as far back as 320 million years ago, suggests that evolution likes to re-run good productions," he said.