Shearwaters

Shearwaters
Great shearwater
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Procellariiformes
Family:	Procellariidae
Genera
Calonectris Puffinus Ardenna Pseudobulweria Lugensa Procellaria Bulweria
Diversity
7 genera and 38 species

Calonectris
Puffinus
Ardenna
Pseudobulweria
Lugensa
Procellaria
Bulweria

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. 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.

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 (flying very close to the water and seemingly cutting or "shearing" the tips of waves) to move across wave fronts with the minimum of active flight. This technique gives the group its English name. Some small species, like the 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) to as far as 70° north latitude in the North Atlantic Ocean off northern Norway. One study found Sooty shearwaters migrating nearly 40,000 miles (64,000 kilometers) a year, which would give them the longest animal migration ever recorded electronically.Short-tailed shearwaters perform an even longer "figure of eight" loop migration in the Pacific Ocean from Tasmania to as far north as the Arctic Ocean off northwest Alaska.

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Wikipedia