Puffins are three species of diving seabirds in the auk family (Alcidae), usually placed in the genus Fratercula. They spend much of the year at sea and feed mainly by diving for fish and other marine prey. During the breeding season, their large triangular bills become especially bright; after breeding, they shed the colorful outer parts of the bill, leaving a smaller, duller beak. All three species breed in large colonies on coastal cliffs or offshore islands. They nest either in burrows dug in soil or in rock crevices, depending on the species and site. The Atlantic puffin lives in the North Atlantic, while the horned puffin and tufted puffin occur in the North Pacific.
