The blue petrel (Halobaena caerulea ) is a small seabird in the shearwater and petrel family, Procellariidae. This small petrel is the only member of the genus Halobaena, but is closely allied to the prions. It is distributed across the Southern Ocean but breeds at a few island sites, all close to the Antarctic Convergence zone.
The blue petrel's plumage is predominantly blue-grey, with an dark "M" extending across the upperwing from wingtip to wingtip. It has a prominent black cap and white cheeks. It is white below apart from dark patches at the side of the neck. The square tail has a white tip. It has a slender black bill. It is 26–32 cm (10–13 in) in length, has a wing span of 62–71 cm (24–28 in) and weighs approximate 200 g (7.1 oz).
The blue petrel inhabits the southern oceans ranging as far north as South Africa, Australia and portions of South America. They mostly only breed in a narrow latitudinal band from 47° to 56° S on either side of the Antarctic Polar Front. Nesting on subantarctic islands, such as the Diego Ramírez Islands, the Crozet Islands, Kerguelen Islands, Macquarie Island, South Georgia, Prince Edward Island.
In 2014 a breeding colony was discovered on Gough Island (40° S, 10° W), central South Atlantic Ocean, more than 700 km north of its known and usual breeding range. Breeding here appears to take place later than at colonies farther south, so although the discovery is recent it does not necessarily represent a recent range extension.
The blue petrel feeds predominantly on krill, as well as other crustaceans, small fish, squid and occasionally insects. It can dive to a depth of up to 6.2 m (20 ft).
The blue petrel, like all members of the Procellariiformes, is colonial, and have large colonies. It nests in a burrow, and lays one egg per breeding attempt. Both parents incubate the egg for approximately 50 days and the chick fledges after 55 days. Skuas are the main danger for their eggs and chicks.
