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Case Summary for:
Submission No 234: Grey Wagtail Motacilla cinerea, Darwin Sewerage Works, NT. 25-31 January 1998. Submitted by: N. McCrie, J.Miles & D. Colbourne. Verdict: Accepted A record that involves the sighting of three Grey Wagtails on a fast flowing stream formed by recent heavy rain outside the well known Leanyer Sewerage ponds in Darwin. Observations were made and notes taken over several days by a number of observers experienced with wagtails in both Europe and Australia. Yellow Wagtails Motacilla flava were also present at the time of the sighting allowing direct comparison. Notes were taken in the field on all three birds and a full account of the circumstances behind each sighting was provided to the committee. The descriptions, although brief, are more than adequate and clearly relate to M. cinerea. Bird No.1, the brightest of the three, is a good match for an adult female in non-breeding plumage due to the combination of clean-white supercilium, chin and throat; bright yellow breast, vent and undertail coverts and intervening white belly and flanks. Adult non-breeding males are said to differ in having a wholly yellow under-body apart from the white chin and throat while first years of either sex have buffy supercilia and throats (in fresh plumage) and a yellow-buff or greyish-buff wash across the breast. Bird No.2, showed a white supercilium, whitish-grey throat, breast and upper belly and yellow lower belly and under-tail coverts, a combination of characters that best fits a bird in worn first immature non-breeding plumage, the greyish tone to the breast being the most indicative ageing pointer. Bird No.3, the dullest individual, showed a combination of indistinct whitish supercilium tinged dull yellow or buff; a similarly coloured throat, a greyish breast and belly, and dull yellowish lower belly, vent and under-tail coverts; it also showed a greyer bill with a noticeable paler base. Thus it would appear reasonable to assume that this individual may also have been a first immature non-breeding bird, albeit fresher than bird no.2 as indicated by the buffy tone. The committee has no hesitation in unanimously accepting all three birds as Grey Wagtails, commenting further, that on the basis of distribution they are most likely of the East Asian subspecies M. c. robusta, which apparently cannot be separated from nominate cinerea in the field (Cramp 1988). This sighting represents the 6th confirmed record for Australia.
References and Bibliography
Tony Palliser |