Dolphin

Dolphins have streamlined bodies, curved dorsal fins, and powerful tails called flukes that propel them up to 30 kilometers per hour. Smooth gray skin minimizes drag, while a layer of blubber insulates them in chilly water. Their beak-like snout houses up to 100 teeth, yet dolphins swallow fish whole. Each dolphin breathes through a single blowhole on top of its head, making it easy to inhale during a quick surfacing between dives.

Bottlenose pods usually contain between 5 and 20 members, though superpods with hundreds of dolphins form when food is abundant. To hunt, dolphins herd schools of fish toward shorelines or circle them into tight bait balls. Individuals take turns slapping tails, blowing bubbles, and lunging through the school with mouths open. Dolphins also use echolocation: clicking sounds travel through water, bounce off objects, and return as echoes that reveal distance and size.

Dolphins are highly social. They greet each other with signature whistles—unique names learned from their mothers—and reinforce bonds by rubbing pectoral fins. Calves nurse for up to 18 months, swimming in their mother’s slipstream to conserve energy. Older dolphins babysit youngsters while mothers dive deep. Playful behaviors, such as bow-riding in front of boats or tossing seaweed in the air, may sharpen coordination that later helps during hunts.

Major threats include entanglement in gillnets, pollution that accumulates in their fat, harassment by tour boats, and habitat loss when coastal wetlands are dredged. Conservation laws like the U.S. Marine Mammal Protection Act limit harassment, require safer fishing gear, and fund rescue teams that disentangle injured dolphins. Researchers photo-identify dorsal fins, attach temporary suction-cup tags, and listen with underwater microphones to track populations and protect important nurseries.