托福口语 Task 4

Today, we're going to talk about a fascinating behavior in the animal kingdom called 'tool use' — but not the kind you might think of, like chimpanzees using sticks to catch termites. I'm referring to a more surprising form, where animals use objects to manipulate other animals, often to their own advantage. One clear example is the 'cowbird trick.' Cowbirds are parasitic birds that lay their eggs in other birds' nests. But here's the twist: a female cowbird will sometimes use a stick or a twig to nudge an already-hatched chick out of the nest, making more room for her own egg to get attention. This is not just random aggression; it's a deliberate use of a tool to achieve a reproductive goal. Another example comes from dolphins. In Shark Bay, Australia, bottlenose dolphins have been observed carrying large marine sponges on their snouts while foraging. This 'sponging' behavior protects their sensitive beaks from sharp coral and stingray spines when they probe the sandy seafloor for prey. It's a learned, socially transmitted technique that females often pass to their daughters. So, in both cases, tool use isn't about getting food directly or building shelter—it's about manipulating the environment or other species to improve survival and reproductive success.