The bill appears large and colourful during the breeding season.
The colourful outer part of the bill is shed after the breeding season, revealing a smaller and duller true bill beneath.
The oldest alcid fossil is Hydrotherikornis from Oregon dating to the Late Eocene while fossils of Aethia and Uria go back to the Late Miocene.
Molecular clocks have been used to suggest an origin in the Pacific in the Paleocene.
Horned puffin burrows are usually about 1 meter (3.3 feet) deep, ending in a chamber, while the tunnel leading to a tufted puffin burrow may be up to 2.75 meters (9.0 feet) long.
The nesting substrate of the tufted and Atlantic puffins is soft soil, into which tunnels are dug; in contrast the nesting sites of horned puffins are rock crevices on cliffs.
The puffins are distinct in their ability to hold several (sometimes over a dozen) small fish at a time, crosswise in their bill, rather than regurgitating swallowed fish.
The head has a black cap, the face is mainly white, and the feet are orange-red.The Fraterculini are thought to have originated in the Pacific primarily because of their greater diversity there; there is only one extant species in the Atlantic, compared to two in the Pacific.The Fraterculini fossil record in the Pacific extends at least as far back as the middle Miocene, with three fossil species of Cerorhinca, and material tentatively referred to that genus, in the middle Miocene to late Pliocene of southern California and northern Mexico.North Atlantic: coasts of northern Europe south to northern France, the British Isles, the Faroe Islands, Iceland, Greenland, Norway and Atlantic Canada then south to Maine.Winters south to Morocco and New York Puffins breed in colonies on coasts and islands; several current or former island breeding sites are referred to as Puffin Island.Their short wings are adapted for swimming with a flying technique under water.