Now listen carefully and answer questions 31 to 40.
I'm going to talk today about research into a particular species of bird, the New Caledonian crow, whose natural habitat is small islands in the Pacific Ocean. And it seems that these crows are exceptionally resourceful. Using sticks or other tools to find food isn't unknown among birds and animals. Some chimpanzees, for example, are known to bang nuts on stones in order to break the shell and get at the edible kernel inside. One New Caledonian crow, called Betty, bent some straight wire into a hook and used it to lift a small bucket of her favorite food from a vertical pipe. This experiment was the first time she'd been presented with wire, which makes it very impressive. Another crow, called Barney, has demonstrated his skill at using sticks to forage for food.