Clever crow finds a feed, but there's a twist,
Date: August 10 2002
Washington: A crow in Britain - Betty by name - has shown researchers she not
only knows how to use items as tools, she makes her own.
Confronted by a small bucket of food inside a pipe, in a laboratory at Oxford
University, Betty figured out how to bend a piece of wire into a hook and
retrieve what she wanted.
And she repeated the success over and over, using the wire to pull the bucket up
by its handle. Her exploits are reported in the journal Science.
Alex Kacelnik, who teaches at Oxford and at the Science College of Berlin, and
his colleagues were trying to determine if the crows, who have been known to use
twigs to pick up things in the wild, could choose the right tool to retrieve
food. However, they did not expect the birds to make their own tools.
"Toolmaking and tool use has always been considered one of the diagnostics of a
superior intelligence," Dr Kacelnik said.
"Now a bird is shown to have greater sophistication than many closer relatives
of us humans."
The Oxford researchers were working with a species of crow known as Corvus
moneduloides, a type that lives in New Caledonia. Two crows, Betty and Abel,
were presented with a small bucket of food inside a tube and two pieces of wire,
one hooked and one straight.
"Our surprise came when, in the fifth trial, the male stole the hooked wire from
the female and took it away. Far from giving up, she then picked the remaining
straight wire and bent it herself," Dr Kacelnik said
"To make sure of our observation we then offered repeatedly only the straight
wire, and she unfailingly did the same trick over and over again."
Both birds had used hooks before, he said. "In fact these crows do use hooks
made out of twigs in the wild."
But wire was new to them, and making a hook of the right dimensions out of a new
and unfamiliar material was strong evidence that at least one animal understood
how tools worked.
Abel was older and stronger than Betty, he said, so while she often showed an
interest in solving tasks, he would wait until she got the food then steal it
from her by brute force.
"This may in fact be an intelligent - if unpleasant - strategy," Dr Kacelnik
said, "and it does not mean that he would not be able to achieve other
solutions, given a different motivation."
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