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. Some animals don't just blend in for a moment—they actively adjust their appearance to match their environment as it changes. This is called dynamic camouflage. Let me give you two examples. First, the cuttlefish. This marine animal can rapidly alter its skin color and texture to match the ocean floor, whether it's sandy, rocky, or covered in seaweed. It does this in seconds, using specialized cells called chromatophores. Second, consider the Arctic hare. In the winter, its fur is pure white, blending with snow. But as spring arrives and the snow melts, the hare gradually molts, growing brown fur that matches the emerging dirt and rocks. This change takes weeks, but it ensures the hare remains hidden from predators like foxes throughout the year. So, dynamic camouflage is not a fixed trait but an adaptive response to seasonal or immediate environmental shifts.