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 have a fixed color pattern; they can actively alter their appearance to match their surroundings, which greatly increases their chances of survival. This is called dynamic camouflage. Let me give you two examples. First, consider the cuttlefish. This marine animal can change both the color and texture of its skin within milliseconds. It uses specialized cells called chromatophores that expand or contract to reveal different pigments. When a cuttlefish rests on a sandy seabed, it becomes sandy brown and smooth; but if it moves to a rocky area with seaweed, it can instantly mimic the mottled pattern and even the bumpy texture of the rocks and algae. This helps it hide from predators like dolphins. Second, there's the Arctic hare. In the summer, its fur is brown, blending with the tundra. But as winter approaches, the hare sheds and grows new white fur, matching the snow. This seasonal change is slower, but equally crucial, allowing it to avoid predators like foxes throughout the year.