Submission No 247: Oriental Reed Warbler Acrocephalus orientalis; Broome, WA. 8 March 1998. Submitted by D Rogers & C. Hassell.

Verdict: Accepted

This submission involves a bird captured while mist-netting passerines as part of a banding program at the Broome Bird Observatory WA on 8 March 1998. The bird was found in a mist net set in a dense, large stand of Avicennia mangroves which normally yields populations of mangrove specialists such as Yellow White-eye, Dusky Gerygone, White-breasted Whistler, Mangrove Golden Whistler, Mangrove Grey Fantail and Broad-billed Flycatcher. The bird was banded, measured, described and photographed before being released. On release, it flew directly into a dense, nearby Avicennia shrub, and skulked away, always remaining low down and flying deeper into the mangroves. It did not call at any time.

The description provided is very thorough and covers all aspects of the birds identification in a most professional and scientific manner. Careful consideration has been made to eliminate similar Acrocephalus species and particular attention was made of the more important field characters. The Measurements proved critical in confirming the identification and provide grounds for establishing the birds sex. As stated by the those submitting the record "the bird was large, with measurements of the wing, tail, bill and tarsus lying near the top of the range for male Oriental Reed Warbler and well above the range for females (Cramp 1992)", therefore strongly suggesting a male. Again as pointed out by the observers; "there were no indications of immaturity found on the bird. The worn primaries, lack of dark tongue spots and asynchronous tail-bars were all consistent with the bird being an adult".

Committee members voted unanimously in favour of acceptance, concurring completely with the banders, agreeing that the combination of measurements , distinct shaft streaks on the fore-neck and several structural characters leaves no doubt as to the birds identity, age and probably sex. The observers are to be congratulated for such a thorough and informative submission. This case represents the 4th record to be accepted by the committee for Australia and the 2nd for Western Australia.

References and Bibliography:

• Christidis, L. & W.E. Boles, 1994. The Taxonomy and Species of Birds of Australia and its Territories. Royal Australasian Ornithologists Union Monograph #2. ROAU; Melbourne.
• Courtney-Haines, L.M., 1991. A Cabinet of Reed-Warblers. Surrey Beatty; Sydney.
• Cramp, S., 1992. The Birds of the Western Palearctic. Volume 6. Oxford University Press; Oxford.
• King, J.R., 1996. Moult of Oriental Great Reed Warbler Dutch Birding 18: 82
• Marchant, S. & P.J. Higgins, 1990. Handbook of Australian, New Zealand and Antarctic Birds. Volume 1. Oxford University Press, Melbourne.
• Mayr, E., 1948. Geographic Variation in the Reed Warbler. Emu 47: 205-210.
• Sangster, G., 1997. Acrocephalus and Hippolais relationships: shaking the tree. Dutch Birding 19: 294-300.
• Shirihai, H., et al. 1995. Identification and taxonomy of large Acrocephalus warblers. Dutch Birding 17: 229-239.
• Stresemann, E. & J. Arnold, 1949. Speciation in the groups of Great Reed Warblers. Journal of the Bombay Natural History Society 48: 428-443.

Tony Palliser
Chairman Birds Australia Rarities Committee (BARC)