Hi Chris G, Beth, Anthony, Chris C, and Philip
Thanks for your thoughts on the 'Tawny angel'. Some interesting critical
thinking there Chris G. I'm not yet convinced though, and am still
leaning towards a Tawny. There are certainly flocks of Sulphur-crested
Cockatoos in Toowoomba; that would be about the right size, (if not a
little too large?) to match the impression. While I don't think they
produce as much as Cockatoos, Corellas and Cockatiels, Frogmouths do in
fact have powder-down feathers. Mr Sophie, the Tawny I nursed, would
produce plenty of powdery, feather dander mess on the floor after a good
preening session, bless him.
Philip, I don't know whether the dust (if all swept up) would differ in
colour between a Tawny (potentially more grey) and a Sulphur-crested
Cockatoo (potentially more white)? Chris G thought the particles of
keratin would be too small to carry a colour and that the
crumbly/fragmented edges would tend to be more white, regardless of the
original colour of the material in bulk. Mr Sophie's feather dust was
sort of off-white...!?
The beak-like impression in question does seem a bit of a stretch, I
agree. What if the beak didn't need to make full contact with the glass
to leave an impression though? While they have huge beaks, if you
observe a 'fluffed up' Tawny you can see they have quite a lot of soft
facial plumage around their beak, in the form of a 'beard' and a
'monobrow' if you like! If the bird hit the window with it's head on a
slight downward angle could this then leave a V-like outline of the beak
perhaps?
I do think the ragged edge to the feather impressions is suggestive of a
Tawny. Compared to a Cockatoo, Tawnys seem to have quite soft and more
'flexible' feathers too, which would enable such an upswept wing
impression.
The height of the impact from the ground (I didn't specify, but from the
photos you can see it is on a lower floor window, about 3 ft above the
pavement) suggests something more like a Tawny than a Cockatoo,
especially if, as Beth suggested, the Tawny was swooping for a mouse
inside the building. I haven't personally seen a mouse Beth, but I
really would not be surprised! Another possibility is that the bird in
question was hawking for moths. Chris Charles said he has seen Tawnys go
for moths against windows, without more than brushing the glass. Maybe
this one misjudged?
The article on the Hilton Pond bird observatory website, posted by
Anthony Overs (thanks Anthony, that was an excellent story, much
appreciated in my office) goes into wing dimensions in detail in their
mission to identify a bird. So perhaps as you suggest Chris G this might
be the best evidence in the photo. This is not my forte!
Thanks again for everyone's contributions.
Cheers,
Plaxy
________________________________
From: Chris Glen
Sent: Thursday, 12 July 2007 3:46 PM
To: Thomas Rayner; Plaxy BARRATT
Cc: ; Dean Ingwersen; peter pfeiffer; Chris
Charles; Barry McLean; R Clarke; Philip Veerman; Geoff Ross; Dave Torr;
keith; Elizabeth Symonds; Peter Kyne; ; Daniel Mantle;
Mike Bennett;
Subject: RE: Tawny angel
As a bit of critical thinking:
'Powder downs' are common through most bird groups (except for ratites
apparently), and essentially are feathers that crumble at the edges to
produce fine powder that aids grooming a nd feather care, or contrbutes
to the colouration of the bird. Though I like the tawny frogmouth idea,
I'm willing to bet it's one of the white cockatoo species. I've had
experience with pet corellas and sulphur crests and there was white
powder everywhere that needed constant cleaning up. Are there large
flocks in Toowoomba? If so that raises the chances (e.g. 20 cockatoos: 1
frogmouth; though I know that's probably dodgey stats application) -
also they're much bolder, somehow flying into a window seems much more
like something a cockatoo would do rather than a frogmouth. And there's
the added possibility of an escaped pet cockatoo being the culprit ('let
me in, it's friggin cold out here in the wilds of Toowoomba!') .
Actually, I recall one of the pet cockatoos leaving an similar angel
shape on the inside of a window.
Admittedly I've only handled a few dead frogmouths in museums and wasn't
taking note of whether they seemed to have much powder down (if it would
remain in such a specimen), Plaxy would know more about that having
nursed one. Possibly the ragged edge to the feather impressions might be
more in favour of a tawny than a cockatoo? I can't say.
I'd say the best evidence in the photo is the impression of the feather
on the allula (halfway along on the front of the wing) - the size and
distance between it and the distal tips of the flight feathers might
give you enough information to ID the bird, if there's enough difference
between species.
I do think it would be impossible for that to be the beak impression, as
the 'bridge' of the beak would prevent the rim of the beak to make
contact with the glass. I think that's a trace of a moving feather tip.
Mmm..yhey (to quote scientist from Simpsons)
Cheers,
Chris
________________________________
From: On Behalf Of
Thomas Rayner
Sent: Thursday, 12 July 2007 2:01 PM
To: Plaxy BARRATT
Cc: ; Dean Ingwersen; peter pfeiffer;
Chris Charles; Barry McLean; R Clarke; Philip Veerman; Geoff Ross; Dave
Torr; keith; Chris Glen; Elizabeth Symonds; Peter Kyne;
; Daniel Mantle; Mike Bennett;
Subject: Re: Tawny angel
Here's the link:
http://tomandzoe.com/log/?p=716
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