Gadfly petrel

The gadfly petrels or Pterodroma are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies (horseflies). The flight action is also reflected in the name Pterodroma, from Ancient Greek pteron, "wing" and dromos, "runner".

The short, sturdy bills of these medium to large petrels are adapted for soft prey that they pick from the ocean surface. They have twisted intestines for digesting marine animals that have unusual biochemistries.

Their complex wing and face marking are probably for interspecific recognition.

These birds nest in colonies on islands and are pelagic when not breeding. One white egg is laid usually in a burrow or on open ground. They are nocturnal at the breeding colonies.

While generally wide-ranging, most Pterodroma species are confined to a single ocean basin (e.g. Atlantic), and vagrancy is not as common amongst the genus as in some other seabird species (c.f. the storm petrels Hydrobatidae). Eleven species in this genus breed in the New Zealand region, and six of these are only found there.

Taxonomy
The genus Pterodroma was introduced in 1856 by the French naturalist Charles Lucien Bonaparte. The genus name combines the Ancient Greek pteron meaning "wing" with dromos  meaning "racer" or "runner". The type species was subsequently designated as the great-winged petrel by the American ornithologist Elliott Coues in 1866.

The species listed here are those recognised in the online list maintained by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC). The genus includes 35 species, of which one has become possibly extinct in historical times.


 * Great-winged petrel, Pterodroma macroptera – Indian and Atlantic Oceans
 * White-headed petrel, Pterodroma lessonii – Southern Ocean
 * Grey-faced petrel, Pterodroma gouldi – Pacific Ocean
 * Atlantic petrel, Pterodroma incerta – south Atlantic Ocean
 * Providence petrel, Pterodroma solandri – west Pacific Ocean
 * Magenta petrel, Pterodroma magentae – south Pacific Ocean, but poorly known
 * Murphy's petrel, Pterodroma ultima – east and central Pacific Ocean
 * Soft-plumaged petrel, Pterodroma mollis – Atlantic Ocean, Indian Ocean and margins of western Pacific Ocean
 * Zino's petrel or Madeira petrel, Pterodroma madeira – east Atlantic Ocean
 * Fea's petrel, Pterodroma feae – Atlantic Ocean
 * Desertas petrel, Pterodroma deserta (disputed) – Atlantic Ocean
 * Bermuda petrel, Pterodroma cahow – northwest Atlantic Ocean
 * Black-capped petrel, Pterodroma hasitata – Atlantic Ocean: Cuba and Hispaniola to Martinique
 * Jamaican petrel, Pterodroma caribbaea (possibly extinct) – Atlantic Ocean: Jamaica
 * Juan Fernández petrel, Pterodroma externa – east Pacific Ocean
 * Vanuatu petrel or Falla's petrel, Pterodroma occulta – southwest Pacific Ocean
 * Kermadec petrel, Pterodroma neglecta – Pacific Ocean with eccentric breeding in the Indian Ocean on Round Island, Mauritius
 * Herald petrel, Pterodroma heraldica – southwest Pacific Ocean – split from P. arminjoniana
 * Trindade petrel, Pterodroma arminjoniana – south Atlantic Ocean, with eccentric breeding on Round Island, Mauritius
 * Henderson petrel, Pterodroma atrata – southeast Pacific Ocean – split from P. arminjoniana
 * Phoenix petrel, Pterodroma alba – southwest Pacific Ocean
 * Barau's petrel, Pterodroma baraui – southwest Indian Ocean
 * Hawaiian petrel, Pterodroma sandwichensis – central Pacific Ocean
 * Galápagos petrel, Pterodroma phaeopygia – central Pacific Ocean
 * Mottled petrel, Pterodroma inexpectata – Pacific Ocean
 * White-necked petrel, Pterodroma cervicalis – west Pacific Ocean
 * Black-winged petrel, Pterodroma nigripennis – west Pacific Ocean with eccentric breeding in the Indian Ocean on Round Island, Mauritius
 * Chatham petrel, Pterodroma axillaris – southwest Pacific Ocean
 * Bonin petrel, Pterodroma hypoleuca – northwest Pacific Ocean
 * Gould's petrel, Pterodroma leucoptera – south Pacific Ocean
 * Collared petrel, Pterodroma brevipes – southwest Pacific Ocean
 * Cook's petrel, Pterodroma cookii – Pacific Ocean
 * Masatierra petrel, Pterodroma defilippiana – east Pacific Ocean
 * Stejneger's petrel, Pterodroma longirostris – north and east Pacific Ocean
 * Pycroft's petrel, Pterodroma pycrofti – southwest Pacific Ocean