birding-aus

Knots and Petrels

To: "'Trevor Ford'" <>, "'birding-aus'" <>
Subject: Knots and Petrels
From: "Jeff Davies" <>
Date: Mon, 19 Oct 2009 01:41:51 +1100
G'day Trevor,

Actually I was never definitive about Great Knot and I am now wondering
after seeing a third image if it is a very long billed female Red Knot. This
would be a better fit with the overall look of the bird as I stated in the
first posting. The following is my most recent post on BirdingOz photo forum
regarding this bird.
" this bird continues to present like a very long billed female Red Knot and
doesn't quite jiz properley for Great Knot, but as we have seen from the
right hand side it has at least one large retained black scapular, which
even though worn is too big for a juvenile scapular, and would indicate
adult Great Knot. A bit more detail is apparent in this extra photo which
doesn't show the plain face, streaked crown I am looking for for great knot.
The breast spotting is also confirmed but it now looks more like retained
breeding plumage rather than fresh winter, and is probably helpful for
female Red Knot. Am I seeing a suffusion of remnant orange in the breast,
did you notice any when looking at this bird Mark?. I have quite a lot of
photos of Red Knot on file and it is not entirely impossible for one to have
a large black scapular, both species are very variable in scapular pattern,
each feather almost a unique variant, but it wouldn't be common let alone
the odds of a black feather being the only old scap left. I'm now leaning
towards female Red Knot"

With regards to under-tail of Soft Plumaged Petrel, the under-tail coverts
are white but the underside of the tail feathers is a contrasting shade of
grey( I probably wouldn't call it "dark grey") and readily discernable in
photos. So no, we were definately not referring to upper-tail. The
"undertail" consists of undertail coverts and under-side of tail feathers,
we are saying they are not both white. Derek Onley has even shown this in
his illustration although he probably could have been a tad darker on the
outer edges, compare image 4a with image 1a on the same page. Paul Scofield
would have been referring to the general view but he doesn't go into
specifics and doesn't refer to the tail feathers as such. 

None of us have said that Peter Ryan deliberately labled his photo a
white-bellied Storm Petrel, I am absolutely certain he didn't. He probably
had no more involvement with the way the image was presented other than
being the photographer, I didn't actually notice the website that hosted the
photo.

Look forward to your response. Cheers Jeff.





-----Original Message-----
From: 
 On Behalf Of Trevor Ford
Sent: Sunday, 18 October 2009 11:38 PM
To: birding-aus
Subject: Knots and Petrels

G'day,

With regard to the recent wader and seabird photos I have no problem with
Jeff - "Great Knot", and Rohan and Jeff - "White-headed Petrel". But I would
like to question their comments regarding the tail feathers (and the
undertail feathers are those visible in the photo) of Soft-plumaged Petrel.

(Rohan has said "Soft-plumaged Petrel can be ruled out as the grey on the
head and breast 
band is usually much darker and they have dark grey tail feathers", whilst
Jeff has said "For an absolute knock out feature then look at the tail which
is white as pointed out by Rohan".)

In the Helm Guide, "Albatrosses, Petrels and Shearwaters of the World" by
Onley and Scofield, it states within the identification section for
Soft-plumaged Petrel: "Uniformly dark underwing, white undertail,....." This
would relate to a pale phase bird, which the bird in the photograph would be
were it a Soft-plumaged.

I don't believe that this is an error in this excellent, albeit occasionally
eccentric book, as I don't recall anything other than whitish undertail
feathers on pale phase birds. Perhaps Rohan and Jeff were considering the
uppertail?

BTW Neither do I believe that Peter Ryan would have called the bird in
question a White-bellied Storm Petrel!!

Cheers - Trevor.

Trevor Ford

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