Petrel Aliblanco

Identificación

Gould's petrel is a small gadfly petrel, white below and dark brown and grey above. The species is classified within the subgenus Cookilaria, all members of which have a dark M pattern across the upper wings. Gould's petrel has long narrow wings, a short rounded tail and the head is noticeably dark, with a white forehead and face. Gould's petrel is 30 cm in length with a wingspan of 70 cm and weighs 180–200 g. Males are slightly larger than females.

Taxonomía

There are two subspecies of Gould's petrel. The nominate subspecies (Pterodroma leucoptera leucoptera) breeds on several small islands off the New South Wales coast in Australia, but primarily on Cabbage Tree Island (John Gould Nature Reserve). The other subspecies (P. l. caledonica) breeds on New Caledonia and differs from the nominate subspecies in being slightly larger in morphological measurements, and having a more robust bill, paler back and sides of the breast, reduced pigmentation on the underside of the wing, and a white or mainly white inner vane of the outer rectrix <p>Some authorities regard the collared petrel (P. brevipes) as another subspecies of Gould's petrel and some raise the New Caledonian petrel to species status and regard the three taxa as a superspecies.

Nombre científico

Pterodroma leucoptera

Autoridad

(Gould, 1844)

Orden

Procellariiformes

Familia

Proceláridos

Género

Pterodroma

Distribución y hábitat

Gould's petrels spend most of their life at sea and come ashore only to breed.<p>Prior to the 1990s it was thought that the Australian subspecies of Gould's petrel bred only on Cabbage Tree Island off Port Stephens in New South Wales. After the discovery of a small number of breeding pairs on neighbouring Boondelbah Island, translocation of 200 chicks in 1999 and 2000 has established a small satellite colony which breeds in artificial nest boxes that were installed prior to the first translocation . In December 2009, just one month after it had been confirmed that rabbits had been eliminated from Cabbage Tree Island, one single Gould's petrel was found incubating an egg on another nearby island, Broughton Island.<p>Today, the nominate subspecies breeds on at least five islands off New South Wales (Cabbage Tree Island, Boondelbah Island, Broughton Island, Little Broughton Island, and Montague Island). The New Caledonian subspecies breeds on New Caledonia on steep forested valleys on the central mountain chain, from 350–500 metres above sea level between Mountains Dzumac and Poya. There is also a small colony on Raivavae in French Polynesia.<p>Both subspecies forage in the Tasman Sea during the breeding season and may venture as far west as the Indian Ocean south of south-western Western Australia before laying. After breeding, Gould's petrel migrates to the central (P. l. leucoptera) and eastern (P. l. caledonica) Pacific Ocean.<p>Gould's petrels (of unknown subspecies) were sighted in December 1994 in waters south of Western Australia. It is deduced that these were not breeding birds, because in December breeding birds are incubating (see Life history below), and these waters are too far from the breeding colonies for a foraging trip.

Área de cría

PO : Cabbage Tree, Boondelbah, Broughton and Little Broughton, and Montague is. (just off se Australia) and montane Grande Terre (New Caledonia)

Área no reproductiva

to Tasman Sea, Antarctica and tropical Pacific to Hawaiian and Galápagos is.

Migración

Complete migrants

Comportamiento

Migration pattern: Complete migrants.

Conservación

Active conservation management for the Australian subspecies of Gould's petrel has removed all land-based threats to the subspecies and the number of islands occupied has increased. However, since 2015 the number of breeding pairs and breeding success at Cabbage Tree Island, where 90% of population breeds, have declined by 20%.<p>At the same time, the population of the New Caledonian subspecies was estimated at 10,000 individuals and decreasing. However, this number is no more than an estimate and scientists do not have high confidence that it is correct.<p>The New Caledonian subspecies is also classified as vulnerable because of its restricted geographic breeding range.

Tendencia poblacional

declining