Pachyptila is a genus of seabirds in the family Procellariidae and the order Procellariiformes. The members of this genus and the blue petrel form a sub-group called prions. They range throughout the southern hemisphere, often in the much cooler higher latitudes. Three species, the broad-billed prion, the Antarctic prion and the fairy prion, range into the subtropics.
Pachyptila
Image: Fairy prion flight
Image: Thin billed Prion 1
Image: Fulmar prion
The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes, which also includes the albatrosses and the storm petrels.
Procellariidae
The flight of giant petrels is aided by a shoulder-lock that holds their wing out without effort.
To take off this Christmas shearwater (Puffinus nativitatis) must face into a strong wind. In calm conditions it must run in order to obtain a high airspeed.
Million-strong flocks of shearwaters migrate from New Zealand to Alaska every year.