ID-FRONTIERS for December 21-27, 2003

Messages are displayed in the order they were received.  Subject  From  Date   Time   Yw Ft Gull Field Mark?   Joel Weintraub    Sun, 21 Dec 2003   8:59am   Re: Variation in Larus thayeri   Kevin McGowan    Mon, 22 Dec 2003   6:55am   Thayer's-like gull in Cambs UK   Dick Newell    Mon, 22 Dec 2003   10:10am   Re: Thayer's-like gull in Cambs UK   Colin Bradshaw    Mon, 22 Dec 2003   10:49am   Re: Thayer's-like gull in Cambs UK   Phillip Pickering    Mon, 22 Dec 2003   11:48am   A small gull at Newport, Oregon   Mike Patterson    Tue, 23 Dec 2003   9:13am   Sapsucker id   Lethaby, Nick   Tue, 23 Dec 2003   2:19pm   Fwd: possible GWGU gull in Texas   Martin Reid    Sat, 27 Dec 2003   6:47am   Re: Fwd: possible GWGU gull in Texas   Phillip Pickering    Sat, 27 Dec 2003   10:16am   Finnish Herring Gulls   Harry Lehto    Sat, 27 Dec 2003   1:33pm   Re: Finnish Herring Gulls   Kevin J. McGowan   Sat, 27 Dec 2003   3:48pm

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Subject: Yw Ft Gull Field Mark?
From: Joel Weintraub <jweintraub(AT)fullerton.edu>
Date: 21 Dec 2003 8:59am

Group,
We have had a Yellow-footed Gull at Doheny State Beach, Dana Point, Orange
County, California... seen two days ago and yesterday (on Christmas Count
Day), and hopefully sticking around.

To my inexperienced eye, when the bird is sitting on the sand or in the
water of the lagoon, it resembles the nearby (and numerous) Western Gulls.
It would be nice to have a field mark that separates the species other than
the bright yellow legs that is readily apparent.   There are subtle (?) bill
dimension differences and size of the red spot between the species, but
looking at a picture of the two,
(see:http://members.cox.net/orcorba/YFG.jpg),
 and granted this is a sample of 1 for each species, I noticed last night
that the feathering on the side of the lower mandible for Western Gull is
like an equilateral triangle with the tip not reaching (1/2 way) to the
forward tip of the feathering of the feathers on the ventral surface of the
mandible; for this specific Yellow-footed Gull the side feathering look more
finger like, and the tip (as seen from the side) almost reaches the visible
feathers on the bottom of the mandible.

Without going back to Doheny (the Gull Capital of California) and actually
doing the observational work, I wonder whether the difference in the photo
reflects individual differences within the species, between the species, or
is an artifact of the angle of the photo.

Joel Weintraub, Dana Point, CA


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Subject: Re: Variation in Larus thayeri
From: Kevin McGowan <kjm2(AT)CORNELL.EDU>
Date: 22 Dec 2003 6:55am

At 08:19 PM 12/20/2003 -0800, Joseph Morlan wrote:
>I've posted three images of a pale 1st year presumed Thayer's Gull from
>Half Moon Bay at:
>
>http://community.webshots.com/album/104073794uAYlcq
>
>The first three shots are of the bird in question with very heavily mottled
>tertials.  This is a feature I have never seen on thayeri before and is one
>thing I look for on Iceland Gull.  Is it from introgression or is it within
>the range of variation of either Thayer's or Iceland?  Is this a bird that
>would be claimed as Thayer's if seen in the East?

This would be one of those worrisome gulls here in the East.  Pretty much
everything else argues for Thayer's, but those tertials would be enough to
make me uncertain.  We get such a variety of things ranging from nearly
pure white Icelands to darkish Thayer's, and everything in between, that I
personally like to have all the characters agree before making a definite
call.  What was the tail like?  It if wasn't completely dark, if I saw that
bird here I'd probably shake my head and call it a really dark
Iceland.  But, I would have called my son's attention to it as something
very different, and we would have photographed the crap out of it.

Kevin

*****************************************************
Kevin J. McGowan
Cornell Laboratory of Ornithology
159 Sapsucker Woods Road
Ithaca, NY 14850
607/254-2432
fax 607/254-2111
kjm2(AT)cornell.edu
http://birds.cornell.edu/crows/


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Subject: Thayer's-like gull in Cambs UK
From: Dick Newell <dick.newell(AT)MACUNLIMITED.NET>
Date: 22 Dec 2003 10:10am

Just to close the loop on the European pale Herring vs Glaucous Gull hybrid
discussion and the Thayer's pictures from Joe Morlan on ID frontiers, not to
mention the recent Thayer's-like gull in Norfolk, UK - how about this for
another try at Thayer's in the UK:
http://www.magikcircle.com/birds/image.asp?title_id=953

Dick, Cambridge, UK


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Subject: Re: Thayer's-like gull in Cambs UK
From: Colin Bradshaw <drcolin.bradshaw(AT)btinternet.com>
Date: 22 Dec 2003 10:49am

maybe I'm missing something but this looks like about 5% of the herring
gulls we get in the NE of England

Colin

-----Original Message-----
From: NBHC ID-FRONTIERS Frontiers of Field Identification
[mailto:BIRDWG01(AT)LISTSERV.ARIZONA.EDU]On Behalf Of Dick Newell
Sent: 22 December 2003 17:08
To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
Subject: [BIRDWG01] Thayer's-like gull in Cambs UK

Just to close the loop on the European pale Herring vs Glaucous Gull hybrid
discussion and the Thayer's pictures from Joe Morlan on ID frontiers, not to
mention the recent Thayer's-like gull in Norfolk, UK - how about this for
another try at Thayer's in the UK:
http://www.magikcircle.com/birds/image.asp?title_id=953

Dick, Cambridge, UK
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Subject: Re: Thayer's-like gull in Cambs UK
From: Phillip Pickering <philliplc(AT)HARBORSIDE.COM>
Date: 22 Dec 2003 11:48am

Thayer's often have a broken eye-ringed look - more
of a tan color than white, but often strongly contrasting
with the darker facial smudge through the eye.

Underparts on this bird look fine for Thayer's. Thayer's can
be quite streaky on the underside, particularly on the breast.

Otherwise the head shape seems to make it a candidate
for Thayer's, but a couple other things look funky.

Primary tips look quite pointed. Juv Thayer's typically appear
more rounded on the tips than this. Bird looks more like
a Herring in this regard. Also, only a small minority of
(theoretically) pure Thayer's show extensive pale on the
tips with isolated subterminal dark spots. Considering that
this is a typical feature of Iceland/Kumlien's (and presumably
Glaucous x Herring if not pure pale-end argentatus), it's not
something you hope to see on an European Thayer's
candidate.

Scaps look quite funky, but hard to tell without better
resolution. Some of the lower (juvenile) look tan-fringed
and pale-centered which is fine, but a lot of the upper scaps
appear to be dark-centered and gray-fringed, almost like
they would have to be 2nd-gen, which would be atypical of
Thayer's in December. Were scaps all juv?

Body appears perhaps a little bulky for Thayer's proportionate
to the head size in the upper photo, but one shot can be
deceiving.

Cheers,

Phil Pickering
Lincoln City, Oregon
philliplc(AT)harborside.com

http://www.magikcircle.com/birds/image.asp?title_id=953


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Subject: A small gull at Newport, Oregon
From: Mike Patterson <celata(AT)pacifier.com>
Date: 23 Dec 2003 9:13am

I was given a couple photos of a small gull taken this
fall in Newport, Lincoln Co., Oregon.  The consensus from
those who've seen the slides so far is that it's a smaller
than average California Gull.  And I agree, the bill and
the wing tips would seem to fit for California.

But there are two very non-quantifiable, arguably irrational
reasons why I'm baulking at dismissing this as a California
Gull.  First, Wayne was very clear in saying the bird was
small and he's seen enough California and Mew Gulls that
I'm obliged to take that statement seriously.  Secondly,
its posture is very Ring-billed/Mew Gull-ish.  If this
bird were just in silhouette at a distance, I'd call it a
Mew Gull.

So anyway, I've seen plenty of California, Ring-billed and
Mew Gulls, but I've never seen one Kamchatka Gull let alone
enough of them to make any claims about the range of variation
possible.  So, feel free to gang up on me and convince me
to trust the left side of my brain, ignore the right side
and let it go as a California.

http://home.pacifier.com/~mpatters/bird/uggu/ugly_gull.html

--
Mike Patterson
Astoria, OR
celata(AT)pacifier.com

You've got to accentuate the positive
        eliminate the negative
        latch on to the affirmative
Don't mess with Mr. In-Between.
                                        - Johnny Mercer

http://www.pacifier.com/~mpatters/bird/bird.html


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Subject: Sapsucker id
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 23 Dec 2003 2:19pm

This message is in MIME format. Since your mail reader does not understand
this format, some or all of this message may not be legible.

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All:

I think this has come up before, but would like to get inputs from those
more knowledgeable than myself. In Santa Barbara, we have a wintering
sapsucker that is fine for a red-naped (has a red nape, correct back
pattern), expect it has a complete red throat patch surrounded by a broad
black line. I scoped the bird and looked at the throat and chin. I got the
impression that there was a tiny thin line of white on chin nearest the
bill, but this could have been caused by misplaced feathers etc.

It seems this bird is either:

a/ A female red-naped with no white on the chin
b/ a hybrid male red-naped x yellow-bellied

Can anyone shed light on how frequent either of these is and any tips for
distinguishing them? Both are rare but more or less annual winter visitors
to the county, with Red-naped a bit commoner histroically.

Nick Lethaby
DSP/BIOS Product Manager
Texas Instruments
nlethaby(AT)ti.com <mailto:nlethaby(AT)ti.com>
(805) 562 5106

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Subject: Fwd: possible GWGU gull in Texas
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 27 Dec 2003 6:47am

Dear All,
I've been asked to seek comment on this bird, seen briefly (not by me) in
Dallas:
<http://www.nctexasbirds.com/gull.htm>http://www.nctexasbirds.com/gull.<http://www.nctexasbirds.com/gull.htm>htm
There is a reasonable possibility that it is a GWGU, so input from those
familiar with this species and its hybrids would be appreciated. It has not
been seen again, but may still be in the area.
Thanks,
Martin

Martin Reid
Fort Worth, Texas
mailto:upupa(AT)airmail.net
http://www.martinreid.com


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Subject: Re: Fwd: possible GWGU gull in Texas
From: Phillip Pickering <philliplc(AT)HARBORSIDE.COM>
Date: 27 Dec 2003 10:16am

It's superficially very G-w-like, but at least based on these
images I don't think it's a safe candidate. The primaries
seem very dark, certainly borderline for a pure G-w. In
particular in the 2nd image down the tertials seem slightly
darker than the body plumage which isn't typical, and in
all the images they look quite dark for a pure 2nd-winter
(presumably would have to be 2nd-winter if G-w).

The head shape seems close, but typically G-w don't show
quite this flat a forehead, usually having more of a noticeable
angle to the slope in front of and above the eye. This
makes the eye placement seem a bit forward for G-w.

The bill shape is also strange in the photos - not really
appearing to match the drawn images. The gonydeal point
seems somewhat inward for a typical G-w, the edge of the
lower mandible inward from the point seems pretty straight
without much hint of being concave, and the section
outward from the point isn't angled upward enough for a
typical G-w. Bill pattern is ok, although the majority of G-w
don't show quite this much pale encompassing the tip more
till 3rd-winter.

Given the location, I think the possibility of this being a
hybrid of some kind is too high to feel safe, although It
could certainly be part G-w.

Cheers,

Phil Pickering
Lincoln City, Oregon
philliplc(AT)harborside.com

http://www.nctexasbirds.com/gull.htm


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Subject: Finnish Herring Gulls
From: Harry Lehto <hlehto(AT)OJ287.ASTRO.UTU.FI>
Date: 27 Dec 2003 1:33pm

Dear Larofiles,
              I just added pictures of 6 Finnish Herring Gulls taken
during the past 10 or so days, showing a couple of normally colored
birds, two birds that are somewhat on the pale side, a darker bird, and a
leucistic bird. The pale gulls are shown partially due to the recent
discussion on pale wingtipped herrings, and the leuctistic herring
is partially due to the recent question on the - was it an italian? - pale
hybrid/herring gull.. I hope this addresses some of the points I made on
the paleness of the wing tips and the possibility of a leucistic
Herring Gull with mainly pale wing coverts. Note that this bird was
photographed yesterday.

http://www.astro.utu.fi/hlehto/photo/gull/argentatus/argdec.shtml

Comments welcome.

Regards
Harry
hlehto(AT)utu.fi


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Subject: Re: Finnish Herring Gulls
From: "Kevin J. McGowan" <kjm2(AT)CORNELL.EDU>
Date: 27 Dec 2003 3:48pm

At 10:33 PM 12/27/03 +0200, Harry Lehto wrote:
>               I just added pictures of 6 Finnish Herring Gulls taken
>during the past 10 or so days, showing a couple of normally colored
>birds, two birds that are somewhat on the pale side, a darker bird, and a
>leucistic bird.
>http://www.astro.utu.fi/hlehto/photo/gull/argentatus/argdec.shtml

Is the pale base to the bill of a first-year bird assumed to be a mark of a
Glaucous Gull hybrid?  Such a bill is extremely common amongst first year
American Herring Gulls around central New York, and wouldn't merit a second
glance around here.  The bill on Fig. 3 can be matched on Herring Gulls
here in every flock.

I would vote for leuciscism, not Glaucous genes on the last gull.  The
white is placed too oddly to be anything "normal."

Kevin

Kevin J. McGowan
Ithaca, NY