Eat, crow! And make your own fork, too
Bird surprises researchers with tool-making skills
By Randolph E Schmid
WASHINGTON -- Millions of frustrated farmers and gardeners can attest that crows are smart. But at least one -- Betty by name -- is at the head of the class. 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 lab at England's 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 a paper in Friday's issue of the journal Science.
"We were delighted and extremely surprised," said Alex Kacelnik, who teaches at Oxford and at the Science College of Berlin.
Kacelnik and his colleagues were trying to determine if the crows, who have been known to use twigs to pick things up in the wild, could choose the right tool to retrieve food.
They did not, however, expect the birds to make their own tools.
Richard Banks, an ornithologist at the Smithsonian's National Museum of Natural History, agreed that it was surprising for a bird to make a tool.
Banks, an expert on North American crows, said he has seen a report of some species using materials as tools, but not actually making them.
Some African chimpanzees have been observed selecting and using stones to open nuts and monkeys are known to use sticks to fish edible ants and termites out of their nests.
"Toolmaking and tool use has always been considered one of the diagnostics of a superior intelligence. Now a bird is shown to have greater sophistication than many closer relatives of us humans," Kacelnik commented.
"People expect apes to be the pinnacle of intelligence in the animal kingdom because they are our closest relatives, but nature may have reached different solutions to similar problems," he said. "There is no doubt that the tool-manufacturing abilities of these animals have evolved independently of that of primates, and this gives us a lever to understand what makes intelligent solutions an advantage."
The Oxford researchers were working with a species of crow known as Corvus moneduloides, a type that lives on the island of New Caledonia in the Pacific Ocean.
Two crows -- Betty and Abel -- were presented with a small bucket of food down 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," Kacelnik explained.
"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, he said, and making a hook of the right dimensions out of a new and unfamiliar material is strong evidence that at least one animal understands how tools function.