托福口语 Task 4

Today, we're going to talk about a fascinating behavioral adaptation in animals called 'mimicry for protection.' Now, mimicry isn't just about looking like something else; it's about gaining a survival advantage by deceiving predators. There are two main types I want to focus on: Batesian mimicry and Müllerian mimicry. Let me give you two examples from the insect world. First, consider the harmless hoverfly. It has black-and-yellow stripes that closely resemble a wasp. Predators, like birds, have learned to avoid wasps because of their painful stings. So, when they see a hoverfly, they mistake it for a wasp and leave it alone. This is Batesian mimicry, where a harmless species imitates a dangerous one. Second, take the monarch and viceroy butterflies. Both are poisonous to birds. Over time, they've evolved to look almost identical. Birds that have eaten a monarch and gotten sick will avoid both species. This is Müllerian mimicry, where two unpalatable species share a warning signal, reinforcing the lesson for predators. So, in both cases, mimicry increases survival, but the underlying strategy differs.