The use of tools was once thought to be a uniquely human skill. Over the past few decades, however, chimpanzees, sea otters, and even some birds have been seen using simple tools such as twigs or rocks. But perhaps the most sophisticated non-human tool user is found on the island of New Caledonia in the southwestern Pacific. This past year, Gavin Hunt of Massey University in New Zealand reported that crows on New Caledonia make and use two kinds of tools.
Unlike the simple, mostly unmodified sticks or rocks favored by other animals, the crows’ tools are carefully selected and shaped. They make one--a hook-shaped stick--by first pulling a small branch off a plant. Next they strip the leaves and nibble at the stick’s end to form a hook, which they insert into knotholes in trees or beneath debris to fish for millipedes, insects, and other prey. The crows make another tool by shearing off leaves from the sawtooth-edged Pandanus plant (inset), tearing the leaves in such a way as to create a sturdy, wedge-shaped strip, which is also used to probe for prey. The wide end is held in the mouth with the barbs running away, says Hunt. It all seems very logical. These guys know what they’re doing.