托福口语 Task 4

Today we're going to talk about a fascinating survival strategy in the animal kingdom: camouflage that changes over time. You might think camouflage is a fixed trait, but some animals adjust their appearance to match their environment as it changes. This is called seasonal camouflage. The main point is that this adaptation allows animals to remain hidden from predators or prey throughout the year, even when their surroundings transform dramatically. Let me give you two examples. First, consider the snowshoe hare. In the winter, its fur is pure white, blending perfectly with the snow. But as spring arrives and the snow melts, the hare molts and grows brownish fur, which matches the dirt and vegetation of the forest floor. This prevents predators like lynxes from spotting them easily. Second, think about the ptarmigan, a bird that lives in Arctic regions. In summer, its feathers are speckled brown and gray, mimicking the rocky tundra. However, when winter comes, the ptarmigan molts to a completely white plumage, making it nearly invisible against the snow. Both examples show how these animals have evolved to change their appearance in response to the seasons, ensuring their survival.