Archive for August, 2007

I’ve always known that crows and ravens were clever birds. They can be downright cunning at times. From a very early age growing up on a farm I was aware of their sneaky habits of flying into the chook yard to steal the eggs.

Over the years I’ve read further examples of these clever birds using tools to get to their food. Some of these indicators of intelligence have been filmed and shown on television. A more recent research programme has demonstrated an intelligence far beyond what was previously thought possible. The following quote comes from The Australian newspaper.

LONDON: Crows, famous for using tools, have even more impressive brains than previously thought.

Seven New Caledonian crows retrieved an unreachable snack with a stick, which first had to be obtained using a shorter stick.

This “metatool” use requires levels of intelligence and reasoning only seen before in humans and great apes.

It may have allowed humans to use simple stone tools to fashion more complex ones.

The new evidence shows a level of understanding similar to that of chimpanzees and orangutans.

University of Auckland scientists placed a meat treat out of the crows’ reach in a 15cm-deep hole. Nearby were two “toolboxes” with vertical bars through which the birds could insert bills, but not their heads.

A stick long enough to fish the meat from the hole was in one toolbox, but too far behind the bars for the crow to reach. The other toolbox contained a stone in the same position.

In front of both boxes lay a stick too short to extract the meat, but capable of reaching the long stick.

All seven crows worked out how to get the long stick and extract the meat.

Further reading:

• A very clever crow
• Clever crows
• Something to crow about
• Ravens and windows
• Thieving birds