Madeiran Storm-petrel
Encyclopedia
The Band-rumped Storm Petrel or Madeiran Storm Petrel, (Oceanodroma castro) is of the storm petrel family Hydrobatidae.
The Band-rumped Storm Petrel is 19–21 cm in length with a 43–46 cm wingspan, and weighs 44-49g. It is mainly black with an extensive white rump. Similar to Leach's Storm Petrel with the forked tail, long wings, and flight behaviour, but Leach's has a more forked tail and differently shaped white rump.
It breeds on islands in the warmer parts of the Atlantic
and Pacific Ocean
s. These include the Azores
and Madeira
in the Atlantic, and the Galapagos Islands
in the Pacific. It nests in colonies close to the sea in rock crevices and lays a single white egg. It spends the rest of the year at sea. They feed by picking up prey items (invertebrate
s, small vertebrate
s and sometimes carrion
) from the water's surface. Occasionally, they make shallow dives, generally to 40–120 cm below the water's surface; a recorded maximum depth of 170 cm seems highly unlikely and is probably due to equipment malfunction.
This storm petrel is strictly nocturnal at the breeding sites to avoid predation by gull
s and skua
s, and will even avoid coming to land on clear moonlit nights. Like most petrels, its walking ability is limited to a short shuffle to the burrow.
Recent discoveries of 'cold season' and 'warm season' populations, which use the same nest sites at different times of year, and also differ in terms of vocalisations and moult, may hint at the existence of two 'cryptic species' within the currently understood limits of the species.
The Band-rumped Storm Petrel is 19–21 cm in length with a 43–46 cm wingspan, and weighs 44-49g. It is mainly black with an extensive white rump. Similar to Leach's Storm Petrel with the forked tail, long wings, and flight behaviour, but Leach's has a more forked tail and differently shaped white rump.
It breeds on islands in the warmer parts of the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
s. These include the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
and Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
in the Atlantic, and the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
in the Pacific. It nests in colonies close to the sea in rock crevices and lays a single white egg. It spends the rest of the year at sea. They feed by picking up prey items (invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, small vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s and sometimes carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
) from the water's surface. Occasionally, they make shallow dives, generally to 40–120 cm below the water's surface; a recorded maximum depth of 170 cm seems highly unlikely and is probably due to equipment malfunction.
This storm petrel is strictly nocturnal at the breeding sites to avoid predation by gull
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
s and skua
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
s, and will even avoid coming to land on clear moonlit nights. Like most petrels, its walking ability is limited to a short shuffle to the burrow.
Recent discoveries of 'cold season' and 'warm season' populations, which use the same nest sites at different times of year, and also differ in terms of vocalisations and moult, may hint at the existence of two 'cryptic species' within the currently understood limits of the species.
External links
- Madeira Birds - Madeira Storm-Petrel
- UMCP Galápagos 2004 - photos of birds at sea