Picture trying to survive in cold coastal waters of the North Pacific Ocean. For many animals, a habitat like this would be impossible. Yet the sea otter, a mammal about 1.2 meters long, thrives there, thanks to features that scientists call adaptations: traits that help a living thing survive in its environment.
Consider the thickest fur of any animal: this adaptation keeps it warm, since it has no blubber. Equally important is a loose pouch of skin under each front leg, which lets it carry food and a favorite rock while it swims. Without these traits, the sea otter would struggle to last a single season.
As a carnivore, the sea otter is an animal that eats other animals; it depends on sea urchins, crabs and clams. Its behavior matters as much as its body: it floats on its back and cracks shellfish open by smashing them on a rock resting on its chest. Behaviors like this are adaptations too, even though you cannot see them in a photograph.
The next generation faces the same challenges. Young sea otters, called pups, depend on their surroundings and on adult care. A pup rides on its mother's belly while she floats on the water.
Perhaps most remarkable of all: sea otters sometimes wrap themselves in seaweed so they don't drift away while they sleep. Facts like this remind us that every animal's body tells a story about the place it lives.