托福口语 Task 4

Today we're going to talk about a fascinating phenomenon in animal behavior called 'tool use.' Now, many people think tool use is unique to humans, but in fact, several animal species have been observed using tools to solve problems in their environment. The key point I want to emphasize is that tool use in animals is not random; it's a learned behavior that is passed down through generations and adapted to local conditions. Let me give you two examples to illustrate this. First, consider the sea otter. Sea otters float on their backs and use rocks to crack open shellfish. They place the rock on their chest and smash the shell against it. Interestingly, each otter selects a rock of a specific size and shape that works best for the type of shell it's eating, and it may keep that rock in its armpit for days. Second, think about the New Caledonian crow. These crows don't just use sticks to extract insects from tree bark; they actually fashion hooks from twigs and leaves to reach larvae in hard-to-reach crevices. What's remarkable is that young crows learn this technique by observing older crows, and the specific hook-making style differs between populations on different islands. So, in both cases, the tool use is not innate instinct but a learned, culturally transmitted skill that shows adaptation to the animal's specific needs and environment.