puffin, common name for a diving bird of the family Alcidae (auk family). Its large, triangular bill, brilliantly colored in yellow, blue, and vermilion, is adapted to carrying several fish at one time; it also gives the puffin its alternate name of sea parrot. During the mating season horny excrescences may develop over the eyes. Puffins have dumpy bodies, short legs set far back, and small wings; although expert swimmers, they are clumsy on land and in flight. They nest in colonies in burrows or rock cavities on northern islands and migrate regularly—the Atlantic puffin, Fratercula arctica, as far south as Long Island and the Pacific puffin, Lunda cirrhata, to California. The female lays a single egg, which is incubated mainly by the female. The chick is fed fish by both parents, and is abruptly deserted after 6 weeks. The adolescent puffin stays alone for another week, and then leaves the burrow alone. Puffins are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Charadriiformes, family Alcidae.

or sea parrot

Any of three species (family Alcidae) of diving birds with a large, brightly coloured, triangular beak. Puffins nest in large colonies on seaside and island cliffs. Both parents carry up to 10 fish crosswise in the bill to the nest (a deep burrow); they feed the single chick for about six weeks. They then leave, and the chick waits alone for its flight feathers to grow, living on stored fat, and then flies out to sea by itself. The common, or Atlantic, puffin (Fratercula arctica) is about 12 in. (30 cm) long. The Pacific species are the horned puffin (F. corniculata) and the tufted puffin (Lunda cirrhata).

Learn more about puffin with a free trial on Britannica.com.