From Encyclopedia Jr, free information reference for Kids
- This article is about the petrel seabirds. For other uses, see petrel (disambiguation). The flammable liquid is correctly spelt petrol.
A
Southern Giant Petrel petrel chick
The petrels are tube-nosed seabirds in the bird order Procellariiformes. The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group (except the Albatross family, Diomedeidae). Having a fossil record that was assumed to exend back at least 60 million years, the Procellariiformes was long considered to be among the older bird groupings, other than the ratites, with presumedly distant ties to penguins and loons. However, recent research and fossil finds such as Vegavis show that the Galliformes (Pheasants, Grouse and relatives), and Anseriformes (ducks, geese and swans) are older[citation needed], while the relationships of the tube-nosed seabirds are still not fully resolved.
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 (Austin, 1996; Bretagnolle et al., 1998; Nunn & Stanley, 1998 and Brooke, 2004):
- The fulmarine petrels: 7 species: surface predators and filter feeders, breed in high latitudes but migrate along cool currents to the north. All but Fulmarus essentially confined to the south, Fulmarus apparently colonised the N hemisphere during the Early Miocene.
- The huge giant petrels, genus Macronectes, which are convergent with the albatrosses,
- The true fulmars, genus Fulmarus,
- Antarctic Petrel Thalassoica antarctica,
- Cape Petrel Daption capense,
- Snow Petrel Pagodroma nivea.
- The prions: A specialised group of a few very numerous species, all southern. They have a small, fulmar-like form and mostly filter-feed on zooplankton.
- Pachyptila, the prions proper
- Blue Petrel Halobaena caerula.
- The procellariine petrels, larger or mid-sized species feeding on fish and molluscs which are fairly close to the prions:
- Procellaria and
- Bulweria.
- Shearwaters: numerous species in several genera with a medium number of species.
- Calonectris,
- Puffinus, which is in fact two rather distinct groups of larger and smaller species,
- Pseudobulweria,
- Kerguelen Petrel Lugensa brevirostris.
- The gadfly petrels: These are a considerable number of agile short-billed petrels in the genus Pterodroma which include the endangered Bermuda Petrel or Cahow and a considerable number of forms rendered extinct by human activity.
The family Hydrobatidae is 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.
[edit] Etymology
The word "petrel" comes from the Latin name for the Christian Saint Peter, and refers to the habits of certain species to hover just above the ocean waves, with their feet barely touching the water, thus giving an appearance of walking on water, as St. Peter is said to have done.
[edit] References
- Austin, Jeremy J. (1996): Molecular Phylogenetics of Puffinus Shearwaters: Preliminary Evidence from Mitochondrial Cytochrome b Gene Sequences. Molecular Phylogenetics and Evolution 6(1): 77–88 DOI:10.1006/mpev.1996.0060 (HTML abstract)
- Bretagnolle, V., Attié, C., Pasquet, E., (1998) "Cytochrome-B evidence for validity and phylogenetic relationships of Pseudobulweria and Bulweria (Procellariidae)" Auk 115(1):188-195 PDf fulltext
- Brooke, M. (2004): Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. ISBN 0-19-850125-0
- Nunn, Gary B. & Stanley, Scott E. (1998): Body Size Effects and Rates of Cytochrome b Evolution in Tube-Nosed Seabirds. Molecular Biology and Evolution 15: 1360-1371. PDF fulltext Corrigendum
[edit] External links
