托福口语 Task 4

Today we're going to talk about a fascinating behavior in the animal kingdom called 'mimicry.' Specifically, I want to focus on how some harmless species evolve to look like dangerous ones to avoid predators. This is called 'Batesian mimicry.' The key point is that the mimic gains protection without having to invest in actual defenses like venom or hard shells. Let me give you two examples. First, consider the scarlet king snake. It has bright red, yellow, and black bands, very similar to the deadly coral snake. Predators learn to avoid coral snakes after a bad experience, and they generalize that fear to the king snake, even though the king snake is harmless. Second, there's the hoverfly. It has black and yellow stripes like a wasp, but it has no stinger. Birds that have been stung by a wasp will avoid hoverflies too. So in both cases, the harmless mimic 'borrows' the reputation of a dangerous model, increasing its survival without any extra cost.