Vanuatu Petrel or Falla's Petrel, Pterodroma occulta is a species of gadfly petrel

Gadfly petrel

The gadfly petrels are seabirds in the bird order Procellariiformes. These medium to large petrels feed on food items picked from the ocean surface....

. This little-known seabird

Seabird

Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

 was first scientifically described

Binomial nomenclature

Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...

 in 2001 based on six specimen

Specimen

A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...

s taken in 1927 off Mere Lava, Vanuatu

Vanuatu

Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...

, and a single found ashore in 1983 in New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The first confirmed breeding locality was only discovered in 2009 on the island of Vanua Lava

Vanua Lava

Vanua Lava is the second largest of the Banks Islands in Torba Province, Vanuatu, after slightly larger Gaua. It is located about 120 km north-northeast of Espiritu Santo and north of Gaua. It has a land area of 314 km². Its population numbered 2,623 in 2009.The island measures about...

, Vanuatu, but based on reports by locals it likely also breeds on Mere Lava. The IUCN have not recognized the Vanuatu Petrel as a species, but maintain it as a subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 of the very similar White-necked Petrel

White-necked Petrel

The White-necked Petrel , also known as the White-naped Petrel, is a species of seabird in the Procellariidae family. During non-breeding season it occurs throughout a large part of the Pacific, but it is only known to breed on Macauley Island in New Zealand's Kermadec Islands and the Australian...

, P. cervicalis, with the "combined" species considered Vulnerable

Vulnerable species

On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...

.

The alternate name commemorates Robert Alexander Falla

Robert Alexander Falla

Sir Robert Alexander Falla was a New Zealand museum administrator and ornithologist.He was assistant zoologist with the British, Australian and New Zealand Antarctic Research Expedition under Sir Douglas Mawson 1929-1931. He was the founding President of the Ornithological Society of New Zealand...

, a New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 ornithologist.

Description

This species resembles the White-necked Petrel, but is slightly smaller at 40 centimetres (15.7 in) in length and 300–350 g (10.6–12.3 oz) in weight. It has a black cap, white rear neck, dark grey back, wings and tail, and a darker rump. The underparts are white with dark bases to the primary feathers. Like White-necked, the upperparts of worn birds become darker.

It is very difficult to separate Vanuatu Petrel from White-necked Petrel at sea.

Behaviour

This is a solitary pelagic species of the open seas of the southwest Pacific. It has an effortless graceful flight with few wing beats, and does not follow ships. It feeds on the wing, picking fish and squid from near the surface.