Submission No 225: Matsudaira's Storm-Petrel Oceanodroma matsudairae; off NW WA, 11-14 October 1996 (unpublished). Submitted by M J Carter, T Palliser and P Milburn

Verdict: Accepted

Groups of between 1 and 15+ birds were observed from the 'Jodi Anne II' traveling from Broome to Ashmore Reef, passing through grid blocks 140S 1220E, 140S 1210E and 130S 1210E. Over the three-days of observations, 55 to 65 birds were seen at varying distances down to 20-30 metres (noting that the potential for multiple sightings of individual birds is not known). Photographic opportunities were limited, however four transparencies of the birds were provided.

The submission describes a large storm-petrel, similar in size to Bulwer's Petrel Bulweria bulwerii, which was available for comparison. The plumage was uniformly sooty brown, with a paler buff-brown crescent-shaped panel across the secondary portion of the wing arcing up towards the carpal, and pale yellowish-white primary shafts. The bare parts were dark. In flight, the birds appeared narrow-bodied and long-tailed, the latter seen to be deeply-forked when viewed well. In purposeful flight the birds appeared long-winged, however when feeding, the wings appeared broader and were occasionally held in a motionless upward dihedral, with the head dropped in a tern-like posture. On the water, the head with steep forehead was held high, and the long wings and tail were held at an inclined angle of about 300. The long wings and tail were prominently shown when the birds were settled. The observers noted that the Swinhoe's Storm-Petrel O. monorhis is smaller, with a significantly shorter, narrower tail and pale primary shafts less evident than those seen.

The Committee considers that the described features are sufficient to confirm the identification, with particular reference to the long pointed wings with pale primary shafts distinctly visible in flight, the crescent-shaped panel or carpal bar on the upperwing, the long deeply-forked tail and the flight behaviour. Although the images are small, the photos do support the described features.A reservation in one Committee member's mind is that the description is general of a number of birds viewed over a period of time, and is not presented in the form of definitive descriptions of the best observed individuals. While this is a valid point, the Committee has resolved to accept the record, based on the descriptive evidence and the supporting photos.

References and Bibliography

• Cubitt, M.G. 1995. Swinhoe’s Storm-petrels at Tynemouth: New to Britain and Ireland. British Birds 88: 342-390.
• Force, M. 1990. Comments on "The Chalice Petrel". British Birds 90: 339-342.
• Gantlett, S. 1988. Matsudaira’s Storm Petrel off Cornwall: A new British Bird. Birding World 1: 285.
• Young, S.A. & King, J.R. 1990. ‘The Chalice petrel’ revisited. British Birds 90: 329-335.
• S Marchant & P.J.Higgins 1990. Handbook of Australian, New Zealand & Antarctic Birds Vol 1 (part A). Oxford University Press. Oxford.
• Harrison P. 1987. Seabirds of The World: A Photographic Guide. Christopher Helm. Bromley.
• Serventy, D.L. et al. 1971. The Handbook of Australian Seabirds. A.H. & A. W. Reed. Sydney.
• Swash, A. 1988. Matsudaira’s and Swinhoe’s Storm Petrels. Birding World 1: 405.

Tony Palliser
Chairman Birds Australia Rarities Committee (BARC)