Crows and magpies show researchers their smarts

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Stories abound about the wily crow’s ability to form seemingly complex thoughts. (Personally, we knew a man whose job duties occasionally included shooing the pesky birds away from the doors of a busy office building. The flock learned to recognize his uniform and specifically sought him, and others in similar clothing, out for dramatic dive-bombings.)

But until fairly recently, scientists haven’t given the birds much credit for intelligence.

‘In the past, people thought birds were stupid,’ Christopher Bird (yes, his real name) of Cambridge University’s zoology department told BBC News. But several recent studies show that the corvid family of birds -- which includes crows, ravens and magpies, among others -- may have been underestimated all these years, especially where reasoning, memory and tool-making abilities are concerned.

One notable instance of corvid intelligence was first shown by a German research team last year. The team studied magpies using the mirror test, pioneered by scientist Gordon Gallup in 1970. The test measures subjects’ self-awareness by determining whether or not they recognize their reflected images in a mirror as themselves. A mark is placed on the subject, in an area of the body not visible without a mirror. If the subject recognizes the mirror image as itself, the reasoning goes, it will try to remove the mark when it notices it in the reflection.

Young children fail this test. So, too, do dogs and cats. Until the German study, the only animals to have passed it were all mammals -- apes, elephants, bottlenose dolphins and orcas. To test the magpies, the researchers placed a colored sticker under their beaks. The result? The birds tried to remove the stickers (see video footage at BBC News). ‘It throws out the assumption that only higher mammals were capable of self-recognition,’ Professor Onur Gunturkun, a co-author of the resulting scientific paper, told the BBC.

Another widely-used measure of animal intelligence, of course, is the use -- or creation -- of tools. University of Auckland researchers noted a species called the New Caledonian crow, found only in a few island groups in the South Pacific, making food-finding tools in the wild.

One New Caledonian crow in particular, named Betty, shocked behavioral ecologists at Oxford University with her impressive use of tools in captivity.

Betty was hatched in the wild but captured as a young bird and brought to Oxford when she was about a year and a half old, head researcher Alex Kacelnik estimated. From the BBC:

The researchers were testing how New Caledonian crows selected tools by presenting them with a small bucket filled with some food, which was placed in a well, and pieces of wire, some straight and some with a hook at the end.

The aim was to see whether the crows would select the bent wire to retrieve the treat-laden bucket.

But Betty astonished researchers when she selected a straight piece of wire and then used her beak to bend it into a hook so she could pull up the bucket of food.

When she was later tested with just the straight wire, Betty repeatedly bent it into hooks - and other experiments with aluminium strips revealed how she would bend, shorten and lengthen the material to get to her food.

This was the first time that any animal had been seen to make a new tool for a specific task, without an extended period of trial-and-error learning.

Just how and why New Caledonian crows are able to perform complex mental tasks usually seen as strictly mammalian is still a mystery. (See video footage of Betty’s tool-making.)

‘They don’t have the area of the mammalian brain that is thought to be the area of intelligent cognition - the neocortex,’ Bird told the BBC. ‘Interestingly, they have another area, the nidopallium, that might do the same job.’

Corvids are smart -- who would have guessed? (Other than someone who’s been repeatedly singled out for dive-bombings, that is.)

--Lindsay Barnett

Video: National Geographic via YouTube.
Photo: Betty the crow