托福口语 Task 4

Today, I want to talk about a fascinating phenomenon in animal behavior called 'biological mimicry.' Specifically, I'll focus on how some harmless animals have evolved to imitate dangerous or unpalatable species to avoid predators. This is known as Batesian mimicry. Let me give you two examples. First, consider the scarlet king snake. This snake is harmless, but it has bright red, yellow, and black bands, very similar to the venomous coral snake. Predators that have learned to avoid coral snakes also avoid the king snake, giving it protection. Second, think about the hoverfly. This insect looks like a bee, with yellow and black stripes, but it has no stinger. Birds that have had a bad experience with a stinging bee will steer clear of hoverflies. In both cases, the mimic gains a survival advantage without actually having the dangerous trait. So, the key point is that mimicry works because predators learn to associate certain visual signals with danger and then generalize that learning to similar-looking harmless species.