Calculating Crows

Behavioral scientists discover that crows may be one of the sharpest tools in the shed.

There's no doubt that crows are clever. Now the brawny, brazen birds have shown scientists just how innovative they can be. Zoologists have observed a captive crow shaping a wire into a hook to retrieve food. The behavior may be more advanced than the tool-making activities of nonhuman primates including chimps.

Alex Kacelnik from Oxford University, UK, and colleagues were testing crow cognition by offering captive New Caledonian crows a choice between a hooked and a straight wire to fetch food from a test tube-sized pipe. One of the cawing competitors, Betty, gave them a surprise-she picked up the straight wire, shaped it into a hook, and fished out the food. The real shocker isn't the fact that the bird used a tool, or even that it made one, but that it did so without prior experience-until now, a feat of reasoning reserved only for humans.

In the wild, New Caledonian crows create tools out of twigs and barbed leaves to scoop insects out of holes in trees or from under leaves. But the researchers contend that these are age-old behaviors that the birds have developed over thousands of years. The researchers reported the finding in the August 9 issue of Science.

Northwestern Crow
Photo: CAS Collection, Dr. Llloyd Glenn Ingles

 


"Betty" a New Caledonian Crow, bent wire into hooks nine times out of ten valid trials. Photo: Alex Kacelnik

Map: Colleen Sudukem