Becks Petrel (Pseudobulweria becki)

Becks Petrel

Subspecies

Genus	Species	subspecies	Region	Range
Pseudobulweria	becki		PO	New Ireland and the Solomons

Genus

Genus Pterodroma, Pseudobulweria and Aphrodroma are also knwon as the Gadfly Petrels. They vary in size from rather small birds such as the Cookilaria-species, measuring about 26 cm, to the much larger and robust representatives of this group like the White-headed Petrel with an overall length of about 43 cm. Their plumages also vary a great deal from species to species; from completely black to light grey mantles and pure white bellies, and with different color phases within species. One feature shared by all of them is the black bill of which the shape also shows much variation. Some species are extremely rare and restricted to a very limited area, other are abundant and wander widely or have unknown pelagic ranges.
The group of the Gadfly Petrels counts over 35 species, mainly from the Southern Hemisphere. There are three genera: Pterodroma with about 30 species, Pseudobulweria counting four and Aphrodroma with only one. Many authors have tried to classify the large number of species of this group and to determine their relationships. This has resulted in a division in several subgenera and the grouping of several species which are considered to have a more or less close relationship. The taxonomic discussion has not come to an end yet: new species have been added or split recently and probably will be in the near future.

Physical charateristics

Small, rather atypical gadfly petrel. Dark, glossy brown upperparts, head and throat. Dark underwings with variably distinct white underwing bar. White breast and belly. Probably solitary at sea, banking and towering more than shearwaters, on straight wings, slightly swept back at tips. Pale throat

wingspan min.:	0	cm	wingspan max.:	0	cm
size min.:	29	cm	size max.:	31	cm
incubation min.:	0	days	incubation max.:	0	days
fledging min.:	0	days	fledging max.:	0	days
broods:	0		eggs min.:	0
			eggs max.:	0

Range

Pacific Ocean : New Ireland and the Solomons

Habitat

The breeding grounds are still undiscovered

Reproduction

Like P. rostrata elsewhere in the Pacific, it probably nests on small islets and/or high mountains on larger islands. The recent records at sea off New Ireland suggest it may well breed in montane forest at the southern end of this island, around Mt Gilaut and the peaks further east and north, including the Hans Meyer range. Although close to the type-locality, the Nuguria Islands seem unsuitable for burrow-nesting petrels, while the 2007 expedition found few birds north of New Ireland and local people did not know of the species in the main island in the Feni group, the only island in this group with substantial montane forest8. Off New Ireland it rarely followed boats for long periods but appeared more tolerant of them than P. rostrata, approaching boats more closely and for longer periods, although this should not be assumed to be a general characteristic or means of identifying the two species.

Feeding habits

No data

Video Becks Petrel

httpv://www.youtube.com/watch?v=HIT8p14Pq40

Conservation

This species has recently been rediscovered, with confirmed records of at least 30 and 160 birds from expeditions in 2007 and 2008. It may have declined severely from depredation by introduced cats and rats on its breeding grounds (which are unknown but thought likely to be include New Ireland). However, the paucity of records is most likely because there have been relatively few searches at sea, plus petrels that are nocturnal at the nesting grounds are notoriously difficult to detect, and there are numerous possible breeding sites on isolated atolls and islands that require surveying. A very small number of mature individuals are currently known, all within a single subpopulation which is suspected to have declined, and it is consequently classified as Critically Endangered. It may however qualify for downlisting in the future if further surveys reveal it to be more numerous than is currently known.
Until recently Pseudobulweria becki was only known from two specimens: a female taken at sea east of New Ireland and north of Buka, Papua New Guinea, on 6 January 1928, and a male taken north-east of Rendova, Solomon Islands, on 18 May 1929. Three birds probably of this species were seen off New Ireland in the Bismarck Archipelago in 2003 and in July and August 2007 an expedition recorded the species on seven days and at at least four localities off New Ireland, with at least 30 recorded in a day and a maximum of 16 together, finally confirming the species’s rediscovery. Cape St George, at the southern end of the island, appeared the most favoured locality, where birds outnumbered Tahiti Petrel P. rostrata, recently fledged juveniles and moulting adults were seen close to land, and a freshly dead fledgling was found8. In 2008 at least 11 were seen off Western Bougainville and Eastern New Ireland in April, and an expedition in July-August found a minimum of 160 birds between New Britain and New Ireland. It seems likely that the species breeds in the montane forests of southern New Ireland such as those around Mt Gilaut and the Hans Meyer range. Additionally a possible record was seen and photographed from a boat crossing the Coral Sea east of Australia’s Great Barrier Reef in 2006, and due to the difficulty of reliable identification in the field a number of records of P. rostrata from the Solomons and Bismarck Archipelago, may also refer to P. becki. The extent of its breeding range and at-sea distribution is still unknown.

Becks Petrel status Critically Endangered

Migration

Not known

Distribution map

Becks Petrel distribution range map

Planet of Birds