Even magpies can recognize themselves

New insights on the development of intelligence and consciousness

Magpie with mark under the beak © RUB
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Not only humans and some other mammals, but also magpies can recognize themselves in the mirror. This has now been proven by Bochum and Frankfurt scientists in a study. The new findings lead to important consequences for our understanding of the evolution of intelligence and consciousness.

A yellow spot under the beak where no one is listening: Magpies look twice when they see their reflection, and immediately start to stain. This behavior shows the researchers Helmut Prior of the University of Frankfurt am Main as well as Ariane Schwarz and Onur Güntürkün, Ruhr-University Bochum (RUB), that even birds in the mirror recognize themselves.

And although the bird brain has no neocortex that was previously believed to be responsible for self-awareness, researchers in the journal PLoS Biology said. This latest part of the cerebral cortex has evolved later in evolution and only in mammals.

Yellow spot in the blind spot

In the nuclear experiment, the researchers marked five magpies with a yellow or a black spot, not visible on the plumage, under the beak, for the bird in the blind spot. All birds underwent the same procedure of marking and were then placed in a test cage. In this cage, a wall was either mirrored or the mirror covered with a plastic plate.

"Only if the bird was marked with a yellow dot and the mirror was uncovered, the magpie began to remove the point, " Güntürkün describes. "This shows us that they actually recognized themselves in the mirror image." Display

Intelligence and awareness came in several ways

This result has several important consequences for the understanding of the evolution of intelligence and consciousness. For birds and mammals have developed separately for at least 300 million years. So far, it has been possible to prove the mirror self-recognition only in a few apes such as chimpanzees and orangutans. Hints were also available for dolphins and elephants.

These results led to the assumption that complex thought processes and consciousness have emerged only in higher mammals. "Proof of self-discovery in magpies, on the other hand, shows that these achievements must have evolved several times and independently of each other, " says Güntürkün.

It works without neocortex

The neocortex, which was especially developed in apes and humans, has long been regarded as an indispensable prerequisite for complex thought processes. Like all birds, magpies do not have a neocortex, but have a completely different brain organization. Thus, the current results show that even self-recognition can be generated without neocortex and thus by alternative brain structures.

(idw - Ruhr-University Bochum / University Frankfurt am Main, 20.08.2008 - DLO)