The black-bellied storm petrel (Fregetta tropica) is a species of seabird in the family Oceanitidae.
Taxonomy and systematics The black-bellied storm petrel was officially discovered and named by the English ornithologist and publisher John Gould in 1844, in the Annals and Magazine of Natural History (now Journal of Natural History). The bird was initially placed in the genus Thalassidroma in 1844 before being reclassified into the genus Fregetta by the French naturalist Charles Lucien Bonaparte in 1885.
Its scientific name means the "little frigate of the tropics", from fregata-, meaning an english frigate (a fast, small warship) and the latin word tropicus, meaning tropical or of the tropical regions.
Subspecies According to ITIS (Integrated Taxonomic Information System), there are currently two subspecies:
F. t. tropica (Gould, 1844): from the islands of the Scotia Arc, across the southern Indian Ocean, to the Antipodes Islands. F. t. melanoleuca (Salvadori, 1908): found on Tristan da Cunha and Gough Island. This subspecies sometimes has a partially or entirely white central belly area.
Regarding the subspecies F. t. melanoleuca, historical confusion led some authors to merge it with White-bellied Storm-Petrel (F. grallaria) or to consider it invalid. Despite the counter-intuitive presence of a white belly, a genetic study published in Molecular Phylogenetics and Evolution clarified its status. Using DNA sequencing, researchers demonstrated that F. t. melanoleuca is a genetically distinct population with limited divergence from the subspecies F. t. tropica, thereby confirming its true phylogenetic affinity with the Black-bellied Storm-petrel.
Description They are usually black with a white band over the rump and white under the wings and on the flanks. A broad black stripe runs down the center of the belly, but may be broken or absent altogether. They have long legs, so the feet can be seen beyond the tail in flight. The legs and feet are black.
This bird has a distinctive way of flying: it slaps its belly against the water and changes direction by kicking its feet. Furthermore, all members of the genus Fregetta feed in an unusual manner, bouncing off the waves using a single foot in an asymmetrical bounding motion.
They are silent mostly at sea. Noises can be heard from the breeding colonies; birds on the ground give a drawn-out shrill whistle.
The Black-bellied Storm-Petrel and the White-bellied Storm-Petrel (Fregetta grallaria) are closely related. In addition to the differing colors, the black-bellied petrel has longer legs, and prefers a more southern, colder habitat.
Distribution and habitat The Black-bellied Storm-petrel inhabits cold sub-Antarctic seas. Some individuals migrate further north in winter (generally from May to August).
Its global population was estimated at approximately 500,000 individuals in 2004.
The black-bellied storm petrel has a large range and can be found across Antarctica, Argentina, Australia, Bouvet Island, Brazil, Chile, Falkland Islands, French Polynesia, French Southern Territories, Madagascar, Mozambique, New Zealand, Oman, Peru, Saint Helena, São Tomé and Príncipe, Solomon Islands, South Africa, South Georgia and the South Sandwich Islands, Uruguay, and Vanuatu.
Behaviour and ecology
Breeding
Food and feeding
Threats The species is threatened by invasive predators introduced to its breeding islands, such as mice, rats, and cats. A population decline is suspected, although the species is classified as Least Concern by the IUCN.
Its natural avian predators include skuas and owls.
Relationship to humans
Status
References
External links Black-bellied storm-petrel [Fregetta tropica] – photos, Christopher Taylor Nature Photography Black-bellied storm petrel first record for Western Palearctic