birding-aus

Raptor ID please

To: "Birding Aus" <>, "Chris Corben" <>
Subject: Raptor ID please
From: "Bill Jolly" <>
Date: Thu, 11 Aug 2005 08:28:02 +1000
Yes, good points Chris.

Collared Sparrowhawk does often looked 'round-tailed' when perched.

Size is something we can't really tell from the photos. If we're trying to
separate from a bird the size of a Brown Falcon, then Brown Goshawk. If
we're looking at something the size of a Hobby, then Collared Sparrowhawk.
If it's a female sparrowhawk versus a male goshawk, who knows?

But, fair enough, on your arguments I agree that Collared Sparrowhawk can't
be definitively ruled out.

All the best

Bill Jolly

"Abberton",
Lockyer Valley, Queensland.

Visit our website at www.abberton.org

email: 
ph: (+61) 7 4697 6111
-----Original Message-----
From: 
 Behalf Of Chris Corben
Sent: Wednesday, 10 August 2005 10:47 PM
To: Birding Aus
Subject: Raptor ID please

> It has to be an accipiter, not a falcon.
> Brown Goshawk.

I am not so sure that Sparrowkawk is that easily dismissed. To me, the face
doesn't look that convincing for a Goshawk, but I'm not sure (long time
since I've seen either that close). I can easily think the bird looks tiny
standing on that post, and what little I can see of a leg looks very
slender.

More importantly, I think people are perhaps being misled by the tail shape.
As I understand it, the roundness or squareness of the tail is a function of
the whole tail, and primarily the relative lengths of outer versus inner
rectrices. The outer rectrices of Sparrowhawk may well be more square ended
than in Goshawk, making the tail corners look more angular and enhancing the
impression of a square tail in Sparrowhawk.But what you are seeing in these
photos is just the central rectrices. Do these differ in shape between
Goshawk and Sparrowhawk? I know that Sparrowhawk does often look
square-tailed when perched, but would it still do so if only the central
rectrices were visible?

Cheers, Chris.

Chris Corben

www.hoarybat.com

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