托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'tool use.' Now, you might think tool use is unique to humans, but many animals actually use tools to solve problems. The key point I want to make is that tool use in animals is not just a random act—it's a learned behavior that can be passed down through generations, showing a form of cultural transmission. Let me give you two examples. First, consider the sea otter. Sea otters often use rocks to crack open shellfish. They float on their backs, place a rock on their chest, and then smash the shellfish against it. Interestingly, young otters learn this technique by watching their mothers, not by instinct. Second, think about the New Caledonian crow. These crows are known to fashion twigs into hooks to extract insects from tree bark. They don't just pick any twig—they actively shape it, stripping leaves and bending the end. Moreover, juvenile crows learn this skill by observing adult crows, and the specific techniques can vary between different crow populations, which suggests a cultural component. So, in both cases, tool use is not innate but is learned socially and varies across groups.