birding-aus

Re: Broad-billed Sandpiper in Cairns

To: "Birding-Aus (Forum)" <>
Subject: Re: Broad-billed Sandpiper in Cairns
From: Chris Sanderson <>
Date: Mon, 7 Jun 2010 11:13:02 +1000
Hi all,

I've been chatting with Ady Boyle about this bird and he has pointed out a
few things about the photo which has made me question the ID.  It looks like
an unfortunate conjunction of circumstances may have led to me calling the
ID without looking closely enough at the image.

Ady has modified the image I provided by upping the brightness/contrast, and
if you look closely at it, it now appears the bill actually ends several
millimetres before the end of the dark patch that appears to be the bill,
before the curve starts.  The dark patch also extends beyond the top of the
bill, which is the part that made me realise that there might be part of the
dark line that was shadow and not bill.

You can see for yourself here:
http://birdo.wildiaries.com/pictures/24029

Or if that isn't convincing enough, I'm happy to email the original file for
people to have a play with.

The other feature I used to call the ID was what appeared to be a split
supercilium, however this appears to have been another trick of the light.
Ady first began to question the ID because the bird appears to be the same
size as the Red-necked Stints around it (a BBS should be larger by at least
20%), and the bill not quite looking right, plus the supercilium not being
strongly split.

Anyway, apart from correcting my mistake, I wanted to put all this out there
for people to read for two reasons.  The first is that I think it's an
interesting discussion on sandpiper ID - I often find people hastily call
Broad-billed Sandpiper without checking the features carefully and I'm
guilty of that here.  The second is it's a salutary lesson in trying to
identify birds from a photograph - things are not always as they appear and
in this case I let myself be fooled by some freakishly unlikely background
shadowing.  My mantra of "believe the bill not the bird" for shorebirds has
let me down!

For reference, I have also uploaded a shot of the Port of Brisbane
Broad-billed Sandpiper from January this year, found at:
http://birdo.wildiaries.com/pictures/24035

You should be able to see the split supercilium and the curve at the bill
tip in this image, and compare to the other.

Anyway, a bit of a red face at my end, but I'd welcome discussion on the
topic regardless.

Regards,
Chris
===============================
www.birding-aus.org
birding-aus.blogspot.com

To unsubscribe from this mailing list, 
send the message:
unsubscribe 
(in the body of the message, with no Subject line)
to: 
===============================

<Prev in Thread] Current Thread [Next in Thread>
  • Re: Broad-billed Sandpiper in Cairns, Chris Sanderson <=
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 birding-aus 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 archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU