shearwater

Shearwaters
Great Shearwater
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Subclass:	Neornithes
Infraclass:	Neoaves
Order:	Procellariiformes
Family:	Procellariidae
Tribe:	Shearwater
Genera
Calonectris Puffinus Pseudobulweria Lugensa Procellaria Bulweria
Diversity
6 Genera and 37 Species

Shearwaters are medium-sized long-winged seabirds. There are more than 30 species of shearwaters, a few larger ones in the genus Calonectris and many smaller species in the genus Puffinus. The Procellaria petrels and Bulweria were believed to belong to this group, but are only distantly related based on more recent studies, while the Pseudobulweria and Lugensa "petrels" are more closely related (Bretagnolle et al., 1998; Nunn & Stanley, 1998). The genus Puffinus can be divided into a group of small species close to Calonectris and a few larger ones more distantly related to both (Austin, 1996). One thing that can be agreed upon about taxonomy of Procellariidae is that it is in a state of flux.

These birds are most common in temperate and cold waters. They are pelagic outside the breeding season.

These tubenose birds fly with stiff wings and use a “shearing” flight technique to move across wave fronts with the minimum of active flight. Some small species, like Manx Shearwater are cruciform in flight, with their long wings held directly out from their bodies.

Many are long-distance migrants, perhaps most spectacularly Sooty Shearwaters, which cover distances in excess of 14,000 km (8,700 mi) from their breeding colony on the Falkland Islands (52°S 60°W) north to 65°-70°N in the North Atlantic Ocean off north Norway. Short-tailed Shearwaters perform an even longer "figure of 8" loop migration in the Pacific Ocean from Tasmania to as far north as the Arctic Ocean off northwest Alaska.

They are also extraordinarily long-lived. A Manx Shearwater breeding on Copeland Island, Northern Ireland, is currently (2003/2004) the oldest known wild bird in the world: ringed as an adult (at least 5 years old) in July 1953, it was retrapped in July 2003, at least 55 years old. Manx Shearwaters migrate over 10,000 km (6,200 mi) to South America in winter, using waters off southern Brazil and Argentina, so this bird has covered a minimum of 1,000,000 km (620,000 mi) on migration alone.

Shearwaters come to islands and coastal cliffs only to breed. They are nocturnal at the colonial breeding sites, preferring moonless nights to minimize predation. They nest in burrows and often give eerie contact calls on their night-time visits. They lay a single white egg.

They feed on fish, squid, and similar oceanic food. Some will follow fishing boats to take scraps, notably Sooty Shearwater; these species also commonly follow whales to feed on fish disturbed by them. Their primary technique for feeding is diving and some species diving as much as 70 m (230 ft) under water.

Shearwaters are part of the family Procellariidae, which also includes fulmarine petrels, prions, and gadfly petrels.

List of species

Unimak Pass Shearwater flock

• Calonectris
  • Calonectris diomedea, Cory's Shearwater
  • Calonectris edwardsii, Cape Verde Shearwater
  • Calonectris leucomelas , Streaked Shearwater

• Puffinus
  • "Puffinus" group - smaller species, closely related to Calonectris
  • Puffinus nativatis, Christmas Shearwater
  • Puffinus puffinus, Manx Shearwater
  • Puffinus yelkouan, Yelkouan Shearwater
  • Puffinus mauretanicus, Balearic Shearwater
  • Puffinus huttoni, Hutton's Shearwater
  • Puffinus opisthomelas, Black-vented Shearwater
  • Puffinus auriculatus, Townsend's Shearwater
  • Puffinus newelli, Hawaiian Shearwater or Newell's Shearwater
  • Puffinus gavia, Fluttering Shearwater
  • Puffinus assimilis, Little Shearwater
  • Puffinus baroli, North Atlantic Little Shearwater
  • Puffinus lherminieri, Audubon's Shearwater
    • Puffinus (lherminieri) baroli, North Atlantic Little Shearwater, not agreed upon as to whether a ssp. or sp.
    • Puffinus (lherminieri) bailloni, Tropical Shearwater or Baillon's Shearwater, not agreed upon as to whether a ssp. or sp.
  • Puffinus heinrothi, Heinroth's Shearwater
  • Puffinus bannermani, Bannerman's Shearwater
  • Puffinus persicus, Persian Shearwater
  • "Neonectris" group - larger species, a distinct lineage
  • Puffinus creatopus, Pink-footed Shearwater
  • Puffinus carneipes, Flesh-footed Shearwater
  • Puffinus gravis, Great Shearwater
  • Puffinus pacificus, Wedge-tailed Shearwater
  • Puffinus bulleri, Buller's Shearwater
  • Puffinus griseus, Sooty Shearwater
  • Puffinus tenuirostris, Short-tailed Shearwater or Mutton bird
  • †Puffinus olsoni, Lava Shearwater or Olson's Shearwater. (extinct)

• Pseudobulweria
  • Pseudobulweria macgillivrayi, Fiji Petrel
  • Pseudobulweria rostrata, Tahiti Petrel
  • Pseudobulweria becki, Beck's Petrel
  • Pseudobulweria aterrima, Mascarene Petrel

• Lugensa
  • Lugensa brevirostris, Kerguelen Petrel

• Bulweria
  • Bulweria bulwerii, Bulwer's Petrel
  • Bulweria fallax, Jouanin's Petrel
  • Bulweria bifax, Small St. Helena Petrel

• Procellaria
  • Procellaria cinerea, Grey Petrel
  • Procellaria aequinoctialis, White-chinned Petrel
  • Procellaria conspicillata, Spectacled Petrel
  • Procellaria parkinsoni, Parkinson's Petrel
  • Procellaria westlandica, Westland Petrel

Footnotes

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

• 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

External links

• Shearwater videos on the Internet Bird Collection