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Case Summary for:
Submission No 221: Oriental Reed Warbler Acrocephalus orientalis, Lake Eda, WA, 28 March 1996. Verdict: Not Accepted This case concerns one and possibly two individuals sighted in dense vegetation in a temporary freshwater lake known as Lake Eda near Broome, WA. The sighting involves three observers, two of which are very familiar with the local Australian Reed Warbler A.stentoreus. The bird in question was brought to the attention of the observers by its confiding nature and subtle plumage differences. The bird was observed within a distance of 2 meters, although unfortunately the call was not heard. The description provided, details a bird with very similar colouration to A.stentoreus. Upperparts uniform brown from the nape to the uppertail coverts. The head when observed at close range was described as being of a slightly lighter shade with a faint eye-stripe. Uppertail coverts more rufous than the back, undersides predominantly off white with a white throat. The flanks and the upper sides of the breast revealed very faint streaks, there being no sign of any streaking on the throat. When the bird flew it appeared to have much longer, more pointed wing than A. stentoreus. The upper mandible was reported to be black and the lower mandible a paler dark grey, overall size of the bill was not noticeably larger than that of A. stentoreus. and the gape colour was noted to be dark orange. After analysing the material carefully the Committee determined that the information provided does not offer sufficient diagnostic evidence to accurately identify this bird as A.orientalis. The lack of any clear dark streaking on the throat and foreneck, the lack of a noticeably heavier bill and in particular the lack of a call, rules out the possibility of positive identification. It was felt that the confiding nature, bill colour and longer winged appearance offered little in the way of features consistent for A. orientalis. The committee would like to point out that without measurements or a recording of the diagnostic call, this species is very difficult to identify and therefore difficult to accept beyond reasonable doubt.
References and Bibliography
Tony Palliser |