Puffins are any of three auk species (or alcids) in the bird genus Fratercula (Latin: little brother — probably a reference to their black and white plumage, which resembles monastic robes) with a brightly coloured beak in the breeding season. These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in crevices among rocks or in burrows in the soil.
All puffin species have large beaks. They shed the colourful outer parts of their bills after the breeding season, leaving a smaller and duller beak. Their short wings are adapted for swimming with a flying technique under water. In the air, they beat their wings rapidly (up to 400 times per minute) in swift flight, often flying low over the ocean’s surface. Similarities in body shape and colour between puffins and penguins are due to convergent evolution.