Hi all,
It looks like I have asked a hard question.
My own research seems to confirm that so I forgive you all (even the wader
wizards) for your almost deafening silence on this matter.
I have received one public response (thank you Frank) and one private email
(thank you T) and I have also had a private conversation with a
famous/infamous local expert about this question.
I have also been analysing my Sooty Oystercatcher photos using the
bare-parts description information in HANZAB* Vol 2.
As a result I have come to some relatively conclusive conclusions on which I
will elaborate to some degree below.
Incidentally, I have added two more photos to my Sooty Oystercatcher Set (
http://www.flickr.com/photos/ptiloris463 ). The photos are of the one bird
and it is a different bird to any of the others.
It is my plan to add detailed notes to the photos but, due to creeping old
age, I can only work at half the speed of light so it may take a short while
for those notes to appear.
I will advise when I have done that job.
In the mean time.........
"Differences are marginal, [.....................], and the species is
probably better considered monotypic."
That is a quote from 'Shorebirds' (Hayman, Marchant and Prater, Croom Helm,
1986) and I am inclined to believe it.
However, in an effort to be a little more constructive, I have, as mentioned
above, been assessing my photos based on the bare-parts description
information in HANZAB Vol 2.
This information has been helpful to some degree in determining the possible
ages of the birds but not so helpful (to me, at least) in determining the
particular race/sub-species.
For example, what is the real difference between 'red-orange' and
'orange-yellow'? Could it be that at some ratio of the colour combination in
each colour the two ultimate colours could appear to be very similar?
And.........what does "duller after breeding" mean? Does it mean the colour
changes or does it mean that the part involved assumes a matte appearance
rather than a glossy appearance without a change of colour? Or does it mean
that it looks like the light has been turned out?
I should also mention that the Simpson and Day (2004) "Field Guide to the
birds of Australia" states that race opthalmicus has a slightly longer bill
than race fuliginosus.
But, the chart of measurements in HANZAB shows that the reverse is the case.
A few notes on the photos:
I am all but convinced that all of the birds depicted, except for the one in
011, are race fuliginosus. I am not certain about the bird in photo 011 but
it appears to me to be different enough from the others to possibly be race
opthalmicus. But I am not prepared to make a definite claim on that one.
Photos 001, 002, 003, 004, 005, 007 and 008 were taken at Caloundra on the
Sunshine Coast in SE Queensland.
Photo 006 was taken at Mooloolaba on the Sunshine Coast in SE Queensland.
Photos 009 and 010 were taken at Cheyne Beach (on a sandy beach without any
sign of rocks) near Albany on the south coast of Western Australia.
Photo 011 was taken at Clontarf Beach on the Redcliffe Peninsula in SE
Queensland.
Photos 012 and 013 were taken at Hastings Point in coastal New South Wales
near the Queensland border.
The bird in photos 009 and 010 (WA) is undoubtedly race fuliginosus as is
the bird in photos 012 and 013 (northern NSW).
These two birds appear to me to be very similar but noticeable different to
the birds in the other photos.
Most significant is the differences in the orbital ring colour and the shape
of the bills.
There is a photo by Graeme Chapman in "Shorebirds of Australia" (Geering,
Agnew and Harding) showing both races in the same frame taken on the west
coast of Western Australia where the territories of the two races overlap.
This photo along with the comment by Frank O'Connor about eye (ring) colour
leads me to believe that the orbital ring colour of 'my' birds is more in
the range of 'red-orange' as for fuliginosus rather than 'orange-yellow' as
for opthalmicus.
That is, except for the bird in photo 011 which I am undecided about.
The bill shape and length of the SE Queensland birds compared to the NSW and
WA birds are interesting and are suggestive (to me) of race opthalmicus,
i.e., shorter and stouter.
It has been suggested to me that this may be a feeding environment
adaptation.
I don't think I am going to get any further with this until I am able to get
some photos of genuine race opthalmicus and I think that might mean a trip
to North Queensland, the Top End or Broome.
Cheers
Bob Inglis
Sandstone Point
Qld
* Handbook of Australian New Zealand and Antarctic Birds,
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