petrel

Petrels are tube-nosed seabirds in the bird order Procellariiformes. Description Petrels are a paraphyletic group of marine seabirds, sharing a characteristic of a nostril arrangement that results in the name "tubenoses". Petrels include three of the four extant families within the Procellariiformes order, including the Procellariidae (fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters), Hydrobatidae (Northern storm petrel, and the Oceanitidae (Austral storm petrel). The other Procellariiformes order are the albatross family, Diomedeidae. Known species All the members of the order are exclusively pelagic in distribution—returning to land only to breed. The family Procellariidae is the main radiation of medium-sized true petrels, characterised by united nostrils with medium septum, and a long outer functional primary feather. It is dominant in the Southern Oceans, but not so in the Northern Hemisphere.