托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'tool use.' Now, contrary to popular belief, tool use is not limited to humans or even primates. Many animals, including birds, have been observed using objects as tools to solve problems. The main point I want to make is that tool use in animals often emerges as a response to a specific environmental challenge, and it can be learned or even innovated within a species. Let me give you two examples. First, the New Caledonian crow. These crows face a challenge: they need to extract insects from deep crevices in tree bark. They have been observed crafting hooks from twigs and leaves to fish out these insects. This is not just a random behavior; it's a deliberate, learned technique that young crows acquire by watching their parents. Second, consider the sea otter. Sea otters eat shellfish like clams and crabs, but their shells are too hard to break with their teeth. To overcome this, otters will float on their backs and use a stone placed on their bellies as an anvil to crack open the shellfish. They often keep a favorite stone with them, carrying it under their arms. So, in both cases, the tool use is a direct adaptation to a specific environmental pressure.