The Manx shearwater (Puffinus puffinus) is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is an Anglo-Norman word (Middle English pophyn) for the cured carcasses of nestling shearwaters. The Atlantic puffin acquired the name much later, possibly because of its similar nesting habits.
It has the typically "shearing" flight of the genus, dipping from side to side on stiff wings with few wingbeats, the wingtips almost touching the water. This bird looks like a flying cross, with its wings held at right angles to the body, and it changes from black to white as the black upper parts and white under sides are alternately exposed as it travels low over the sea.
This shearwater is mainly silent at sea, even when birds are gathered off the breeding colonies. It calls on its nocturnal visits to the nesting burrows in flight, on the ground, and in the burrows, although moonlight depresses the amount of calling. The vocalisations largely consists of a raucous series of croons, howls, and screams, typically in groups of a few syllables, which become weaker and throatier. The male has some clear ringing and shrieking tones absent from the harsher repertoire of the female, the difference being obvious when a pair duets.