canberrabirds

Collared Sparrowhawks anyone?

To:
Subject: Collared Sparrowhawks anyone?
From: "Paul T." <>
Date: Sat, 15 Aug 2009 10:31:20 +1000
At 05:37 PM 14/08/2009, you wrote:
Yes. On the basis of the tail shape is really obvious. It also shows big white spots. Is that a recent thing? I commented several weeks back that these are likely to be pale feather bases made visible during moulting. However this and a few other recent local photos suggest I was wrong in that. Are we getting a plumage pigmentation deficiency?

Philip et al,

If it was a pigmentation deficiency, would the effect be perfectly symmetrical?  If you look at the white feathers (or part feathers) on either wing they match absolutely perfectly (allowing for one white patch which looks like it could be covered by a brown feather on the other wing?).  Unless all these feathers grew at the same time (and coincided with a deficiency or something that can cause feather bleaching) would they be perfectly mirrored like this?  What are the odds of all those feathers being replaced at exactly the same rate?  Is it possibly just a genetic "colour form" unique to this bird?

Fascinating picture, that is for sure.

Cheers.

Paul T.
Higgins, ACT ******************************************************************************************************* This is the email announcement and discussion list of the Canberra Ornithologists Group. List-Post: <> List-Help: <> List-Unsubscribe: <> List-Subscribe: <> List archive: List manager: David McDonald, email <>

<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the Canberra Ornithologists Group mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the list contact David McDonald, list manager, phone (02) 6231 8904 or email . If you can not contact David McDonald e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU