Ravens Plan for the Future - Just Like Humans

Ravens match great apes at planning Mathias Osvath  Lund University

"It's pretty wonderful in that it works, functionally at least, in a similar way in ravens as in apes, and you don't see it in many other animals", says Mathias Osvath, a cognitive zoologist at Lund University in Sweden.

First, ravens were trained to drop a simple tool, a stone, into a puzzle box through an opaque tube, causing the box to release a reward from an opening in the bottom. 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. After all, compared to mammals, birds have small brains relative to their bodies, and bird brains lack a neocortex, which in mammals is thought to be the seat of higher-order thinking such as reasoning, problem-solving, language, and delaying gratification. When it comes to meal planning, corvids like the Western scrub-jay (Aphelocoma californica) can prepare breakfast for the following morning.

Until recently, planning for the future has generally been considered to be unique to humans.

To take a closer look, the team put the birds through a series of exercises that were originally carried out on great apes.

A third experiment tested "planning in a self-control context". One hour later, the ravens were given the stone, as well as several "distractors" such as a wooden wheel, a wooden ball, a metal pipe and a toy auto.

It's not like you could ask a raven to arrange your wedding: Ravens showed they could plan by setting aside a tool that they suspected would get them a tasty treat later. When the ravens were presented with the box 15 minutes later, they used the tool to open it, and with a success rate of 86 per cent.

The ravens were made to choose between useless trinkets, tools to retrieve a reward or a token that could be exchanged with a human for a reward, all at a later time and in another location. Similar results were achieved in the second experiment, in which the birds waited 17 hours for the box to reappear. Once again, the ravens smashed the tool selecting test with a score of 89 percent. The ravens demonstrated self-control on par with great apes by opting for the tool, which eventually earned them a better food reward than the immediate treat.

"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". What they did was to present the ravens with a tray that contained the stone or bottle cap, the distractors, and an immediate reward. The team also offered an instant reward in addition to the reward in the box.

In one experiment, the ravens were shown the box, but without any stones available. They also tested their self control - whether the ravens were willing to forgo an immediate reward for a bigger one in the future - over two different time periods. By the way, ravens are great imitators - they can even mimic the voice of a man.

Their findings, which were just published in Science show ravens outperformed chimpanzees, orangutans, bonobos, and even human children, on similar tests.



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