Orcas, or killer whales, are the largest of the dolphins and one of the world's most powerful predators. They're immediately recognizable by their distinctive black-and-white coloring. Smart and social, orcas make a wide variety of communicative sounds, and each pod has distinctive noises that its members will recognize even at a distance. They use echolocation to communicate and hunt, making sounds that travel underwater until they encounter objects, then bounce back, revealing their location, size, and shape.

(Learn more about the unique culture of killer whales.)

Though they often frequent cold, coastal waters, orcas can be found from the polar regions to the Equator. They're at the top of the food chain and have very diverse diets, feasting