Hi Greg and all
Not sure on any scientific basis either but I have seen a white morph Grey
Goshawk flying with a group of Sulphur-crested Cockatoos around the Dungog
area. The presumption being they are using the cockatoos as camouflage to
"sneak" up on unsuspecting prey. Maybe other people have had similar
experiences.
Cheers
Dick Jenkin
Dungog ( 70kms north of Newcastle NSW )
-----Original Message-----
From:
On Behalf Of Greg and Val
Clancy
Sent: Sunday, 13 January 2013 9:27 AM
To: Jeremy O'Wheel; Rosemary Royle
Cc: COG line; Birding Aus; Denise Goodfellow
Subject: Re: [Birding-Aus] [canberrabirds] Why are the C. Sparrowhawk &
B.Goshawk so similar?
Whether there is any scientific basis for the ‘cockatoo theory’ or not I am
sure that the white underparts would assist in camouflage in the sky.
Greg
Dr Greg. P. Clancy
Ecologist and Birding-wildlife Guide
PO Box 63 Coutts Crossing NSW 2460
0266493153 0429601960
From: Jeremy O'Wheel
Sent: Sunday, January 13, 2013 12:09 AM
To: Rosemary Royle
Cc: COG line ; ; Greg ; Denise Goodfellow ; Birding Aus
Subject: Re: [Birding-Aus] [canberrabirds] Why are the C. Sparrowhawk &
B.Goshawk so similar?
The problem with the cockatoo theory is that in Tasmania there is good reason
to think Sulphur-crested Cockatoos are recently introductions, but all the Grey
Goshawks are white morph. Also Grey Goshawks have a white underside regardless
of morph, and that's the side prey would normally see. I suspect the underside
is white for sky camouflage (like the White-breasted Sea-eagle and a number of
other diurnal birds of prey), while the upper surface possibly represents
genetic drift, or sexual selection.
Jeremy
On 12/01/2013 11:56 PM, "Rosemary Royle" <> wrote:
During our latest trip to Australia, up above Gunlom Falls in the NT we
spotted a dead branch laden with Sulphur-crested Cockatoos plus what appeared
to be a smaller white cockatoo. It wasn't, it was a white-morph Grey Goshawk,
and it had obviously chosen to perch with the cockatoos. .
Only on reading this thread does that sighting make sense.
Rosemary
Rosemary Royle, Wales, UK
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