托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry' — specifically, how certain animals use mimicry not just for camouflage, but as a defensive strategy to avoid predators. Now, there are two main types of this defensive mimicry: Batesian mimicry and Müllerian mimicry. Let me give you two examples to clarify. First, consider the scarlet king snake. It is harmless, but it has bright red, yellow, and black bands that closely resemble the venomous coral snake. Predators learn to avoid the coral snake's colors, and they also avoid the king snake because it looks the same. This is Batesian mimicry, where a harmless species imitates a dangerous one. Now, for Müllerian mimicry, take the case of two different species of poisonous butterflies — the monarch and the viceroy. Actually, both are toxic to birds, but they have similar orange and black patterns. By sharing the same warning signal, predators learn more quickly to avoid all butterflies with that pattern, which benefits both species. So, in both cases, mimicry increases survival, but the mechanism differs.