Memorandum to: The Director of Birds Australia
From: Birds Australia Rarities Committee (BARC)
Date: 12th February 2007
Voting Members: Andrew Silcocks Mike Carter
Glenn Holmes John Hatch
Tony Palliser Rohan Clarke
Jamie Matthew Danny Rogers
Expert Opinion: Hadoram Shirihai
Cc. David Stewart
Submission No 489:
Beck’s Petrel Pterodroma becki
This submission concerns the
sighting of a bird considered by the observer to be a Beck’s Petrel Pterodroma becki on the 7th
November 2005. The bird was observed and photographed while aboard the
expedition ship ‘Clipper Odyssey’. Although the precise co-ordinates have not
been provided the sighting was ‘reportedly’ just within Australian territory in
the Coral Sea off the coast of
The bird was described as a small Pterodroma, considerably smaller than Tahiti Petrel Pseudobulwaria rostrata, but no other birds were present for direct size comparison. It generally resembled that species being a similar dark brown blackish appearance above and with a similar paler centre to the underwing. The observer also noted that it appeared to have a pale throat that maybe consistent with the type specimen of Beck’s Petrel. The flight mannerism was described as vaguely similar to that of Tahiti Petrel, but slightly less languid. The bill was considered to be comparatively small giving a different appearance to the small-headed & large-billed appearance of rostrata.
This is a bird for which there are no authenticated reports of live birds from anywhere in the world. Even reports from the region where the only two specimens were collected, the North Solomons, are considered at the best to be only possible. This sighting was at least 700 Nm (1300 km) from that region, placing the claim as extremely unlikely. Also, it is not known what this species looks like in the field so there is nothing on which to make a judgement. We do know that in plumage it resembles Tahiti Petrel but that it is much smaller and that the bill of Beck’s is noticeably proportionately smaller than that of Tahiti Petrel.
Seven of the eight voting members and Hadoram Shirihai (who provided the committee with expert opinion after the voting process) voted against acceptance, commenting that the photographic images appeared within the range of variation for Tahiti Petrel including the possible perception of an apparently smaller than normal bill. Also, to those on the committee experienced with Tahiti Petrel, the bent-back outer-wing showing in one of the photographs and the extent of pale on the underwing looked typical for the species. .
There is a slim chance that this bird could have been a Beck’s Petrel but too little is known about this species to be certain, at least until we have better information and more comparative material for assessing the identification of the species at sea.
References and Bibliography:
· Enticott, J. & Tipling, D. (1997), Photographic Handbook of the Seabirds of the World, New Holland, London.
· Marchant, S. & Higgins, P.J. (Eds) (1990), Handbook of Australian, New Zealand & Antarctic Birds. Vol. 1, Ratites to Ducks, Oxford University Press, Melbourne.
· Hadden, D. (2004), Birds and Bird Lore of Bougainville and the North Solomons, Dove, Alderley, Queensland.
· Harrison, P. (1983), Seabirds: an identification guide, Croom Helm, Beckenham, Kent.
· Harrison, P. (1987), Seabirds of the World: A Photographic Guide, Christopher Helm, London.
· Monroe B.L. & Sibley, G.S. (1993), A World Checklist of Birds, Yale, New Haven.
· Warham, J. (1990), The Petrels; their ecology and breeding systems, Academic Press, London.
Chairman, Birds Australia Rarities Committee