What about the colours of the bare surfaces? Plumage can be
unreliable, but bill, eyes, legs etc should help the diagnosis. Does
it behave like the locals?
Regards, Laurie.
On Thursday, January 19, 2006, at 04:39 PM,
wrote:
Hi,
There is a strange looking shelduck at the Western Treatment Plant
(near Werribee, Victoria) at the moment. It was initially found and
reported by Gina Hopkins about 4 months ago, and seen by Maarten
Hulzebosch who noticed its potential similarity to Cape Shelduck (a
South African species). It then escaped notice until Bob Swindley
relocated the bird last week and on Tuesday 17th, Richard Loyn and
Danny Rogers were able to spend half an hour enjoying good views of
it; Rohan Clarke saw it the next day. Others looked for it today with
no luck. Both Danny and Rohan obtained some low quality photos of it.
None of the observers have been able to make a positive
identification. The bird does have some features of Cape Shelduck,
and other features that do not fit the pictures we have seen of that
species.
If you go looking for it, it has been on 145W Lagoon, Pond 18 - after
you have crossed the Little River Ford and turned right towards the
coast, that's the 4th large pond on your left, before the cattle grid.
The bird has been perching on the banks on the north-western corner in
company with a large flock of Australian Shelducks, and swims into the
middle of the lagoon when disturbed. First impressions are likely to
be of a shelduck with a conspicuous light brown head.
On closer examination the bird differs from Australian Shelduck in
many ways. While similar in size, it appears to have a longer tail;
the bill appears a little shorter and finer, and the head appears
rounder, with a steeper forehead. The breast is bright rufous, similar
in colour to the breast of male Australian Shelduck, but that's about
where the similarity ends. The head pattern is very strange and
distinctive: mostly light greyish brown, with a dark brown hindneck
and crown; the dark brown of the crown broadens and projects down to
surround the eye, and there is a diffuse, very pale brown wash across
the upper face, appearing strongest behind the eye. Most of the body
is warm brown - not as rusty as a Ruddy Shelduck, but certainly not
the blackish colour found in Australian Shelduck. It has deep rufous
tertials, and very distinctive rufous undertail coverts and vent,
neatly separated from the flanks by an iridescent blackish line that
runs down from the rump towards the! cloaca. We heard the bird call
three or four times (it was the only duck on the wetland that was
calling) - it was similar in pitch to female Australian Shelduck, but
it was a single note call with a rising inflection "kror".
ID still baffles us, but it is very difficult to reconcile the
appearance or call of the bird with Australian Shelduck. The
possibility remains that it is a Cape Shelduck, a South African
species never before recorded outside Africa. This is by no means
confirmed; most plumage characters seem OK but the head pattern is
inconsistent with the better known plumages of that species. However
we do not know a great deal about immature Cape Shelduck. Another
possibility is that it is a hybrid, perhaps involving Ruddy Shelduck
which is kept in captivity. The head is darker than the breast, and
several other features rule out Ruddy Shelduck itself (a much more
likely species to occur than Cape Shelduck, either as a vagrant or an
escapee). If it is a Cape Shelduck, the brownish head would make it
an immature, and we have seen no good photos of immature Cape
Shelduck. The species is said to be quite common in southern Africa,
and makes regular movements to moulting areas bu! t no long-distance
migration.
Whatever the duck is (and wherever it came from), it is a good-looking
and interesting bird, well worth a look if you are passing that way.
Please remember that you need a permit and key to get into the Western
Treatment Plant, and try not to disturb the bird unnecessarily, not
least as relocating the bird (among the 100,000 waterfowl that occur
in the WTP) would be a a tricky proposition. If anyone obtains better
descriptions, photos or recordings we would be very interested.
Richard Loyn
Danny Rogers
Laurie & Leanne Knight
--------------------------------------------
Birding-Aus is on the Web at
www.birding-aus.org
birding-aus.blogspot.com
--------------------------------------------
To unsubscribe from this mailing list, send the message:
'unsubscribe birding-aus' (no quotes, no Subject line)
to
|
