Petrel


Petrels are tube-nosed seabirds in the bird order Procellariiformes.

Description

The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group. Having a fossil record that was assumed to extend back at least 60 million years, the Procellariiformes was long considered to be among the older bird groupings, other than the ratites, with presumably distant ties to penguins and loons. However, recent research and fossil finds such as Vegavis show that the Galliformes, and Anseriformes are still not fully resolved.

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. It is dominant in the Southern Oceans, but not so in the Northern Hemisphere.
It includes a number of petrel groups, the relationships between which have finally been resolved to satisfaction.
The families Oceanitidae and Hydrobatidae are the storm petrels, small pelagic petrels with a fluttering flight which often follow ships.
The family Pelecanoididae is the four species of diving petrels, genus Pelacanoides. These are auk-like small petrels of the southern oceans.
The word petrel comes from earlier pitteral; the English explorer William Dampier wrote the bird was so called from its way of flying with its feet just skimming the surface of the water, recalling Saint Peter's walk on the sea of Galilee ; if so, it likely was formed in English as a diminutive of Peter.