ID-FRONTIERS for December 10-16, 2000

Messages are displayed in the order they were received.  Subject  From  Date   Time   Lesser Yellowlegs in Spain   Ricard Gutierrez    Mon, 11 Dec 2000   4:53pm   Tundra and Bewick's Swans   Steven Mlodinow    Mon, 11 Dec 2000   7:53pm   Question: the Pa. gull   Paul Hess    Wed, 13 Dec 2000   5:53am   Re: Question: the Pa. gull   Katrina Knight    Wed, 13 Dec 2000   7:21am   American Birds photo   Matt Hafner    Thu, 14 Dec 2000   5:12pm   POSSIBLE Easton Mystery Gull ID?   Dave DeReamus    Fri, 15 Dec 2000   12:30am   Re: American Birds photo, FL Ross' Gull?   Andrew Kratter    Fri, 15 Dec 2000   9:25am   Easton, PA mystery gull   McMorris, F. Arthur   Fri, 15 Dec 2000   9:40am   Easton PA Mystery Gull   Robert H. Lewis   Fri, 15 Dec 2000   4:03pm   Hybridization in large gulls   Angus Wilson    Fri, 15 Dec 2000   4:59pm   Re: Hybridization in large gulls   Lethaby, Nick   Fri, 15 Dec 2000   6:06pm   Re: Hybridization in large gulls   Mike Patterson    Fri, 15 Dec 2000   6:26pm   Probable Omissus-type Herring Gull in Nova Scotia   Robert H. Lewis   Fri, 15 Dec 2000   10:01pm   Unusual gull from Niagara Conference   Martin Reid    Fri, 15 Dec 2000   10:21pm   Re: Hybridization in large gulls   Alvaro Jaramillo    Fri, 15 Dec 2000   10:59pm   Re: American Birds photo   Alan Wormington    Sat, 16 Dec 2000   8:18am   American Birds photo   Andrew Kratter    Sat, 16 Dec 2000   9:57am   Re: American Birds 'Little Gull' photo   Bill or Sue Smith    Sat, 16 Dec 2000   1:16pm   Kelp Gulls in the Caribbean   Robert H. Lewis   Sat, 16 Dec 2000   6:54pm

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Subject: Lesser Yellowlegs in Spain
From: Ricard Gutierrez <GUTARB(AT)terra.es>
Date: 11 Dec 2000 4:53pm

Hello:
In the web Rare Birds in Spain (http://www.terra.es/personal3/gutarb ) I've
put a couple of pages dealing with the current 1st winter bird present in
the Mediterranean coast of Spain including photos showing moulted scapulars
and rest of plumage as well as some large format pictures of this bird.
Statistics on accepted records in Spain are included as well. Staying here
since 16 November it could turn up to be the 2nd ever overwintering T
flavipes in Spain after a bird seen early the nineties in the Canary
Islands.

Thank you for having a look

Ricard Gutiérrez
12.12.2000


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Subject: Tundra and Bewick's Swans
From: Steven Mlodinow <SGMlod(AT)AOL.COM>
Date: 11 Dec 2000 7:53pm

Greetings All

A Bewick's Swan was first reported near Vancouver, BC about 2 weeks ago.
Yesterday, Ryan Shaw and I went and took a look.

For reasons that are unclear to me, Madge and Burn 1988 (Waterfowl) states
that "for field purposes, the two are clearly separable" when referring to
Bewick's and Tundra Swans. Though there appears to be no overlap in
percentage of bill covered by yellow (Evans and Sladen, Auk 97:697-703),
these taxa show enough variability that certain birds might be extremely
difficult to separate in the field via this trait. Also, hybrids seem to
exist, further muddying the waters. For further discussion regarding this
mark see Patten and Heindel 1994 (Birding 26:306-318), Knapton 2000 (Birders
Journal 9:130-133), and Birding World 12:125-127.

The bird we saw in BC had yellow clearly passing over the base of the bill,
thus eliminating Whistling. Also, from a side view, the yellow seemed to
cover 40-50% of the bill surface. So, I think that the ID is not in doubt.

Now, to the point. The Birding World article (actually more a letter to the
editor and a response) mentions the possible utility of neck shape and head
shape. The bird in BC was a bit far away to judge head shape, but the neck
shape was clearly different. Indeed, I could pick the bird out from the flock
more quickly using the neck than the bill color because of the distance
involved. The neck was visibly shorter and thicker than any of the 20 or so
Whistling Swans it was with. Also, it appeared to be paired with a Whistler,
so hybrids down the line?

Finally, last winter I saw a bird that appeared to be a Whistling Swan with
more yellow on the bill than normal (but still within range of Whistling and
outside range of Bewick's). This bird had yellow on the underside of the
bill, a mark which Patten and Heindel tentatively suggest might be indicative
of Bewick's. I think this bird was a Tundra, meaning that the mark is not
absolute, though I guess it could have been a hybrid.

Cheers
Steve Mlodinow


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Subject: Question: the Pa. gull
From: Paul Hess <phess(AT)SALSGIVER.COM>
Date: 13 Dec 2000 5:53am

Hello.

I fear that the question may have an embarrassingly obvious answer but
curiosity is nagging me, so here goes:

What was it about the Easton, Pennsylvania, mystery gull (which  received
much interesting and valuable discussion this month) that eliminated the
Asian "Herrings" heuglini, taimyrensis, and/or vegae?

I have no experience with them, but my general impression from the
literature has been that they are relatively dark mantled, relatively
large, and sometimes have yellowish legs.  I don't recall seeing them
mentioned in the recent ID-Frontiers discussion, so I'm clearly missing
something.

Thank you and best regards,
Paul Hess
Natrona Heights
Pennsylvania USA
phess(AT)salsgiver.com


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Subject: Re: Question: the Pa. gull
From: Katrina Knight <kknight(AT)EPIX.NET>
Date: 13 Dec 2000 7:21am

On 07:52 AM 12/13/00 Paul Hess wrote:
>What was it about the Easton, Pennsylvania, mystery gull
>(which  received
>much interesting and valuable discussion this month) that eliminated
>the
>Asian "Herrings" heuglini, taimyrensis, and/or vegae?

To muddy the waters further, there appear to be at least two gulls that
fit the same general description in eastern Pennsylvania. There is a
second bird at Lake Ontelaunee, outside of Reading, which is about 50
miles driving distance southeast of Easton, a bit less as the gull
flies. I've been hearing reports of this bird since mid-November, but
hadn't seen it myself until this weekend. The birds were seen in both
places Saturday, no more than an hour apart, so I think we have two.
(How fast do gulls normally fly?) I also saw yet another bird at
Ontleuanee with the same mantle color on Sunday. The main difference
between the birds that I could see when they are standing is that I
think the Ontlaunee bird's bill doesn't seem to have quite as much of a
curved, hooked appearance but I'm not sure how much that is a matter of
looking from a different angle. The Ontelaunee bird also is further
along in molt - P10 looks a bit shorter than P9, but not a lot. How
fast does a primary feather grow in?

My take on the answer to Paul's question: Heuglini are the darkest of
Herring Gulls, many as dark as L. f. graellsii and they are larger on
average than other Herring Gulls. The mystery gulls are only a little
darker than our usual Herring Gulls and not nearly as dark as the
Lesser Black-backs here (which are presumably L. f. graellsii). The
mystery gulls are both either slightly smaller or the same size as the
Herring Gulls, not larger.

Taimyrensis are also larger on average and supposedly only have faint
head streaking in winter and my impression from reading descriptions of
them is that they are darker than our mystery gulls.

Vegae - I'm not sure this one is ruled out - Sibley says that they have
a yellow gape, but that this is unconfirmed. The Easton bird has a red
gape and the Ontelaunee bird has at least a reddish gape - I've only
gotten one look at it, in poor lighting - it might be orange-red or
dark pink, but it isn't yellow. Also, the illustration in Sibley makes
it appear that vegae has less black on the under side of the wingtips
than the mystery gulls. How often do vegae have yellow legs? Grant says
they always have pink legs, Sibley shows them with pink legs and
doesn't say anything else about it, Harrison's _Seabirds_ says pink or
yellow legs. How am I supposed to stay unconfused when my references
say different things? :)

Can the gull experts comment on whether what I say here is true?
Reading books is no substitute for experience and about the only thing
I can say from experience about these mystery gulls is that they are
like nothing I've ever seen before. It seems that nothing described in
the books actually fits these gulls completely and the books aren't
good at describing how much variation there is in each subspecies.

--
Katrina Knight
kknight(AT)epix.net
Reading, PA


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Subject: American Birds photo
From: Matt Hafner <MH1920(AT)AOL.COM>
Date: 14 Dec 2000 5:12pm

Hello all,

I'm a teen birder and interested in learning more about bird identification.
I've spent some time looking through old American Birds/Field Notes to further
my knowledge.  I read through the field reports and try to ID the pictures as
they appear.  I feel that I've learned a great deal about distribution and
identification by doing this.  However, scanning through pictures has made me
ask some questions.  The particular bird I would like to ask about in this
message can be seen in the May 1979 issue of American Birds on page 276.  It is
a small gull taken in Ft. Pierce Harbor, FL on Jan. 14, 1979 by Alan Wormington.

I would be interested to know the field marks that make this gull a Little Gull
(Larus minutus).  My first impression of the bird was that is appeared to be a
Ross's Gull (Rhodostethia rosea).  The field marks that jumped out at me were
the clean white cap, doe eye, and the short, petite bill.  Other field marks
that led me to Ross's were the primary pattern and overall structure.  The
primaries appear to have white inside linings as opposed to being completely
black.  The primaries also appear rather long and the crown peaked.  My overall
first impression of the bird was that it was a Ross's Gull.

I have never seen a Ross's, and have only seen about 10-12 Little Gulls.  That
is why I am asking for input as to what makes this bird a Little Gull.  I would
not like to mistake a Little Gull as my life Ross's Gull.  The main question
seems to be: Can Little Gull show a pale and peaked crown as this bird does?
Also, can Little Gull show this type of primary pattern?  I have not found a
source that says so, but perhaps someone on this list has more experience.
Thank you in advance for any information you can provide.

Matt Hafner
University of Maryland, College Park


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Subject: POSSIBLE Easton Mystery Gull ID?
From: Dave DeReamus <becard(AT)FAST.NET>
Date: 15 Dec 2000 12:30am

Hi all,

First, I want to thank all of the birders who responded to my request for
help on the Easton, PA mystery gull.  It has been an education to say the
least.

I continue to try and get better photos of the bird, but have been
unsuccessful, usually because the distance to the bird has been farther than
when the original photos were taken.

At this point, after reading, rereading, and spending hours looking at
suggested website photos and information, I am going to stick my neck out
and state that it appears to me that the 'closest fit' to this gull seems to
be a "Siberian" Heuglin's Gull (Larus heuglini taimyrensis).  This
suggestion was previously mentioned by a few of those who responded to the
photos.  Realizing how unusual this would be, I am asking for further
comments and suggestions that would corroborate or rule out my 'best guess'
conclusion.  Understand that I have no previous experience with this bird
other than the photos and information that I've researched since this bird
was found.  It certainly seems to be a much closer match than that of any
form of Yellow-legged, especially when considering the pattern of its head
streaking.

Here are the points that have me leaning toward this identification:

1)  Size nearly matches or seems a little smaller than surrounding Herring
Gulls, but appears too large for Lesser Black-backed;
2)  Head shape seems a little more rounded than surrounding Herring Gulls;
3)  Bill has larger, somewhat rectangular, red gony spot than surrounding
Herring Gulls;
4)  Leg color is yellow (though not bright yellow), sometimes showing a
slight pinkish cast to the feet;
5)  Iris is pale yellow with red orbital ring;
6)  Gape appears to be red or orange-red;
7)  Head has light streaking on crown, getting thicker as it runs farther
down the breast and nape, giving the nape a dark 'collared' look to it;
8)  Underwing's trailing edge (secondaries) has a subterminal grayish bar;
9)  An obvious white crescent is present on the tertials;
10)  Mantle color is lighter than any Lesser Black-backed that I've seen,
yet easily stands out as darker than any of the surrounding adult Herring
and Ring-billeds;
11)  Underparts, rump, and tail are pure white.

Unfortunately, I cannot give any more precise details on the primaries than
have already been given by other observers.

I have included some web addresses that have photos and information
concerning this particular possibility.

"Siberian" Heuglin's Gull (Larus heuglini taimyrensis) photos:
http://www15.freeweb.ne.jp/animal/larus/Tai_ad001111/tai_ad001111.html
http://www15.freeweb.ne.jp/animal/larus/taimy1125ad/taimy1125adCh.html

"Siberian" Heuglin's Gull (Larus heuglini taimyrensis) detailed description:
http://www.geocities.com/RainForest/Canopy/6181/heug_d.htm

Pictures of the Easton gull are at the following websites:
http://www.martinreid.com/gullsp17.html
http://www.fordham.edu/lewis/birds/easton/easton.html

ANY feedback on this possibility would be greatly appreciated.  As one
birder noted, given the increasing number of reports of Black-tailed Gull
here on the East Coast, I guess 'taimyrensis' probably isn't that much more
impossible.

Thanks again and Good birding,

Dave DeReamus
'Eastern PA Birdline' Compiler
Easton, PA
becard(AT)fast.net
Remember that birds can't read range maps!


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Subject: Re: American Birds photo, FL Ross' Gull?
From: Andrew Kratter <kratter(AT)FLMNH.UFL.EDU>
Date: 15 Dec 2000 9:25am

Responding to the posting from Matt Hafner:

  I looked at the Am Birds photo mentioned, and then looked at several
references (Grant, Lars Jonsson Europe guide, NGS, Little Gull BNA account)
and none mentioned that Little Gull can lack a dark crown, none show Little
Gull such a small bill or large eye, and none show Little Gull with
extensive white on inner 5-6 primaries (although Jonsson says that the
amount of white in the primaries is variable).  I think Matt may be  right,
but I would like to look at original photos (at Tall Timbers apparently,
not here).  An additional point: in the photo it actually looks like the
outer 2 rectrices are much shorter and that the black terminal band may be
restricted to the central few pairs of rectrices  --- the photo is pretty
fuzzy though and this may be an illusion.  What is needed now is to look at
the original  photos, and consult with some people who know these gulls
well (not me!).

Andy Kratter

 > X-Mailer: Unknown
 >Date:         Thu, 14 Dec 2000 19:11:51 EST
 >Reply-To: MH1920(AT)AOL.COM
 >Sender: NBHC ID-FRONTIERS Frontiers of Field Identification
  >             <BIRDWG01(AT)LISTSERV.ARIZONA.EDU>
 >From: Matt Hafner <MH1920(AT)AOL.COM>
 >Subject:      [BIRDWG01] American Birds photo
 >To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
 >X-DomainScript: FLMNH.UFL.EDU\\script.mml
vX-Script: \\filterscript.mml
 >X-UserScript: FLMNH.UFL.EDU\kratter\script.mml
 >
 >Hello all,
 >
 >I'm a teen birder and interested in learning more about bird
identification.  I've spent some time looking through >old American
Birds/Field Notes to further my knowledge.  I read through the field
reports and try to ID the >pictures as they appear.  I feel that I've
learned a great deal about distribution and identification by doing
this.  >However, scanning through pictures has made me ask some
questions.  The particular bird I would like to ask >about in this message
can be seen in the May 1979 issue of American Birds on page 276.  It is a
small gull taken >in Ft. Pierce Harbor, FL on Jan. 14, 1979 by Alan Wormington.
 >
 >I would be interested to know the field marks that make this gull a
Little Gull (Larus minutus).  My first impression >of the bird was that is
appeared to be a Ross's Gull (Rhodostethia rosea).  The field marks that
jumped out at me >were the clean white cap, doe eye, and the short, petite
bill.  Other field marks that led me to Ross's were the >primary pattern
and overall structure.  The primaries appear to have white inside linings
as opposed to being >completely black.  The primaries also appear rather
long and the crown peaked.  My overall first impression of the >bird was
that it was a Ross's Gull.
 >
 >I have never seen a Ross's, and have only seen about 10-12 Little
Gulls.  That is why I am asking for input as to >what makes this bird a
Little Gull.  I would not like to mistake a Little Gull as my life Ross's
Gull.  The main >question seems to be: Can Little Gull show a pale and
peaked crown as this bird does?  Also, can Little Gull show >this type of
primary pattern?  I have not found a source that says so, but perhaps
someone on this list has more >experience.  Thank you in advance for any
information you can provide.
 >
 >
 >Matt Hafner
 >University of Maryland, College Park
Dr. Andrew Kratter, Collections Manager- Ornithology
Florida Museum of Natural History
PO Box 117800
University of Florida
Gainesville, FL 32611 USA
Ph. (352) 392-3293
Fax (352) 846-0287
http://www.flmnh.ufl.edu/


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Subject: Easton, PA mystery gull
From: "McMorris, F. Arthur" <mcmorris(AT)WISTAR.UPENN.EDU>
Date: 15 Dec 2000 9:40am

Dear Birders,

I want to thank everyone who has posted on the Easton, PA mystery gull and
especially Dave DeReamus for keeping track of all the discussion and for
posting summaries on BirdWG01 and PaBirds. This is indeed an interesting
gull - and the drama continues.

I had an opportunity to study the bird at leisure on Dec. 3 with Katrina
Knight, Jennifer Hanson and others, and have followed the discussion and
read and re-read all my gull literature without coming up with an ID.

Dave has suggested that the gull may be a "Siberian" Heuglin's Gull (Larus
heuglini taimyrensis, or Larus argentatus heuglini/taimyrensis, depending
on how it is split or lumped). I have no first-hand experience with
heuglini/taimyrensis, but I checked the reference Dave gave:

"Siberian" Heuglin's Gull (Larus heuglini taimyrensis) detailed description:
http://www.geocities.com/RainForest/Canopy/6181/heug_d.htm

I agree that most of the features fit the mystery gull well, but there is
one striking exception: the bill. The bill of "Siberian" Heuglin's Gull is
described as "quite slim with little gonydeal angle." In contrast, one of
the major things that struck me about the Easton gull was its heavy bill,
much heavier and with a sharper gonydeal angle than the herring gulls
(smithsonianus) it was with. This feature was so striking that, to my mind,
it eliminates heuglini/taimyrensis.

The beat goes on......

Good birding!

Art

F. Arthur McMorris, Ph.D.
Professor
The Wistar Institute
3601 Spruce St.
Philadelphia, PA  19104
USA

215-898-3865  office
215-898-3866  lab
215-898-3868  fax
McMorris(AT)wistar.upenn.edu


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Subject: Easton PA Mystery Gull
From: "Robert H. Lewis" <lewis(AT)BWAY.NET>
Date: 15 Dec 2000 4:03pm

Hi,

  Dave DeReamus has just sent me some very good photos of the Easton bird,
taken by Alan Brady.  I have just now added them to my gull web site, on the
page

http://www.fordham.edu/lewis/birds/easton/easton.html

which has had 9 photos of the bird since December 4.

  I don't know much about the Asian birds in the Herring Gull complex, and
maybe it is one of them, as has been suggested.  However, I still think it
is probably either a large pale Lesser or a hybrid Lesser X Herring.  The
new Brady photos showing the wings are consistent with that.  Compare the
birds on this page:

http://www.fordham.edu/lewis/birds/Jan96/jan96.html

Bob Lewis
Sleepy Hollow NY
http://www.bway.net/~lewis/birds/gulls.html


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Subject: Hybridization in large gulls
From: Angus Wilson <wilsoa02(AT)ENDEAVOR.MED.NYU.EDU>
Date: 15 Dec 2000 4:59pm

This may be a naive question but can anyone point me towards photographs
(published or on the web) of KNOWN Lesser Black-backed X Herring hybrids in
adult or near adult plumage?

I have run into plenty of examples in which hybridization is inferred but have
not come across any where it is actually proven. I am troubled by the frequent
identification of 'problem birds' as hybrids when there is so little
information
on what they should actually look like. Is it safe to assume they will be
intermediate for many characters? Based on information from other bird groups
(e.g. albatrosses), the reality may be more complicated than this.

I recall documentation of interbreeding between L. fuscus graellsii X L.
agentatus argenteus (in the UK) and imagine there are similar combinations
involving L.f. intermedius (e.g. from the Netherlands?). Perhaps Norman van
Swelm and other Dutch gull experts can help? Have the offspring of any of these
conjugations been followed to adulthood? I realise that graellsii x
smithsonianus hybridization has not yet been documented nor is it likely in the
forseeable future.

Continuing with the hybridization theme, can readers in the Pacific NW comment
on the degree of individual variation between suspected F1 generation Glaucous-
winged X Western Gull hybrids? Are these more variable than the 'pure' parental
species or about the same? Obviously this is a difficult question to answer
given the terrifying degree of individual variation in most large gull species
but perhaps experienced observers have some thoughts?

Angus Wilson

**************************************
Angus Wilson
New York City
wilsoa02(AT)endeavor.med.nyu.edu
Check out the "Ocean Wanderers" bird ID web site.
http://www.best.com/~petrel/index.html
**************************************


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Subject: Re: Hybridization in large gulls
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 15 Dec 2000 6:06pm

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.

----INCLUDING text/plain MIME SECTION----

All:
I think that hybrids are not always intermediate between parents. For
example, I have often noticed that obvious GWGU x WEGU hybrids can show
relatively pale eyes, even though WEGU (occidentalis) is dark-eyed and GWGU
is somewhat dark-eyed. However, I would also offer the caveat that, at least
on the wintering grounds, it's very difficult to know where hybrid GW Gulls
stop and pure birds begin. GW Gulls themselves vary geographically in the
darkness of their wing tips. Birds wintering in Japan are darker than many
of those in the US. For example, in CA I have commonly seen 1W GW Gulls with
very white wing tips. Small individuals of these provide an id pitfall as
possible Iceland Gulls. With this level of variation, it's hard to how a GW
x Glaucous hybrid, or WEGU x GWGU hybrid, or HEGU x GWGU hybrid differs from
a regular GW Gull. Even when you have an obvious hybrid with really dark
wing tips, you then have the problem of separating HEGU x GWGU from WEGU x
GWGU. This makes it very difficult to be sure of what you are looking at.

-----Original Message-----
From: Angus Wilson [mailto:wilsoa02(AT)ENDEAVOR.MED.NYU.EDU]
Sent: Friday, December 15, 2000 3:00 PM
To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
Subject: [BIRDWG01] Hybridization in large gulls

Continuing with the hybridization theme, can readers in the Pacific NW
comment
on the degree of individual variation between suspected F1 generation
Glaucous-
winged X Western Gull hybrids? Are these more variable than the 'pure'
parental
species or about the same? Obviously this is a difficult question to answer
given the terrifying degree of individual variation in most large gull
species
but perhaps experienced observers have some thoughts?

Angus Wilson

**************************************
Angus Wilson
New York City
wilsoa02(AT)endeavor.med.nyu.edu
Check out the "Ocean Wanderers" bird ID web site.
http://www.best.com/~petrel/index.html
**************************************

----DELETED text/html MIME SECTION----


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Subject: Re: Hybridization in large gulls
From: Mike Patterson <celata(AT)pacifier.com>
Date: 15 Dec 2000 6:26pm

Bell, Douglas A. 1996. Genetic Differentiation, Geographic
Variation and Hybridization in Gulls of the Larus Glaucescens-
occidentalis Complex. Condor 98:527-546.

Bell, Douglas A. 1997. Hybridization and Reproductive performance
in Gulls of the Larus Glaucescens-occidentalisComplex.
Condor 99:585-594.

> -----Original Message-----
> From: Angus Wilson [mailto:wilsoa02(AT)ENDEAVOR.MED.NYU.EDU]
> Sent: Friday, December 15, 2000 3:00 PM
> To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
> Subject: [BIRDWG01] Hybridization in large gulls
>
> Continuing with the hybridization theme, can readers in the Pacific NW
> comment
> on the degree of individual variation between suspected F1 generation
> Glaucous-
> winged X Western Gull hybrids? Are these more variable than the 'pure'
> parental
> species or about the same? Obviously this is a difficult question to
> answer
> given the terrifying degree of individual variation in most large gull
> species
> but perhaps experienced observers have some thoughts?
>
> Angus Wilson
>
> **************************************
> Angus Wilson
> New York City
> wilsoa02(AT)endeavor.med.nyu.edu
> Check out the "Ocean Wanderers" bird ID web site.
> http://www.best.com/~petrel/index.html
> **************************************

--
Mike Patterson               Alas, to wear the mantle of Galileo,
Astoria, OR                  it is not enough to be persecuted
celata(AT)pacifier.com            by an unkind establishment,
                             you must also be right.
                                                     ---Robert Park
http://www.pacifier.com/~mpatters/bird/bird.html


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Subject: Probable Omissus-type Herring Gull in Nova Scotia
From: "Robert H. Lewis" <lewis(AT)BWAY.NET>
Date: 15 Dec 2000 10:01pm

Hi,

  Relevant to the Easton Pa. gull discussion is another mystery bird.  Ian
McLaren has sent me some photos of a bird that was the subject of an article
"Probable Yellow-legged Gull in Nova Scotia", Birder's Journal 4 (1995):
302-304, describing a bird thought to be a Yellow-legged Gull (L. cachinnans
michahellis).  Since then, however, the record has been criticized and it
now appears to be more likely a Herring Gull of the "omissus" type, i.e. a
yellow-legged form of the northern European Herring Gull L. argentatus
argentatus.

  I have just put up the photos as a page on my gull site,

http://www.bway.net/~lewis/birds/novasc/nomiss.html

  Thanks, Ian.

Bob Lewis
Sleepy Hollow NY
http://www.bway.net/~lewis/birds/gulls.html


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Subject: Unusual gull from Niagara Conference
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 15 Dec 2000 10:21pm

Dear all,
I've been asked to post this message so that those who saw this unusual
gull at Niagara can look at the image - and hopefully to solicite
discussion on Id-Frontiers.
http://www.martinreid.com/gullsp18.html
Cheers,
Martin

Martin Reid
upupa(AT)airmail.net
http://www.martinreid.com  or  http://www.cyberramp.net/~upupa


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Subject: Re: Hybridization in large gulls
From: Alvaro Jaramillo <alvaro(AT)SIRIUS.COM>
Date: 15 Dec 2000 10:59pm

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At 07:06 PM 12/15/00 -0600, Lethaby, Nick wrote:

>All:
>I think that hybrids are not always intermediate between parents. For
>example, I have often noticed that obvious GWGU x WEGU hybrids can show
>relatively pale eyes, even though WEGU (occidentalis) is dark-eyed and
>GWGU is somewhat dark-eyed. However, I would also offer the caveat that,
>at least on the wintering grounds, it's very difficult to know where
>hybrid GW Gulls stop and pure birds begin. GW Gulls themselves vary
>geographically in the darkness of their wing tips. Birds wintering in
>Japan are darker than many of those in the US. For example, in CA I have
>commonly seen 1W GW Gulls with very white wing tips. Small individuals of
>these provide an id pitfall as possible Iceland Gulls. With this level of
>variation, it's hard to how a GW x Glaucous hybrid, or WEGU x GWGU hybrid,
>or HEGU x GWGU hybrid differs from a regular GW Gull. Even when you have
>an obvious hybrid with really dark wing tips, you then have the problem of
>separating HEGU x GWGU from WEGU x GWGU. This makes it very difficult to
>be sure of what you are looking at.

I agree, and what one has to do is to consider that you aren't really
making an identification of these birds per se but proposing an hypothesis
of what they are. You may never be able to test your hypothesis directly,
but  as more information comes out on hybrids from the breeding grounds we
will be able to gain confidence in the validity of these hypotheses. On the
other hand work published on known hybrids or birds from the hybrid zones
do appear to look intermediate in many respects to the parent species. This
suggests that in most of the traits obvious to us such as size and
structure, wing tip melanism, mantle colour etc, their expression is
controlled by a complex of genes rather than a much more simple genetic
control. Multi-genic characters are much more likely to average out in
hybrids than take one of two states as is the case in most plumage
characters of hybrids between Blue-winged and Golden-winged Warblers for
example. Sometimes, and this occurs in ducks, traits coded by genes but not
expressed by either parent species can come out (be expressed) in the hybrids.

Finally, Western Gulls commonly have pale eyes so it is not unusual at all
for supposed hybrids to have pale eyes as well.

cheers,

Al

Alvaro Jaramillo
Biologist
San Francisco Bay Bird Observatory
P.O. Box 247
Alviso, CA 95002
(408)-946-6548

http://www.sfbbo.org/
Home of the California Fall Challenge!!

alvaro(AT)sirius.com

Birds of Chile and
New World Blackbirds at : http://www.sirius.com/~alvaro

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Subject: Re: American Birds photo
From: Alan Wormington <wormington(AT)JUNO.COM>
Date: 16 Dec 2000 8:18am

Everyone,

This is the THIRD person to enquire about this photo of Little Gull in
American Birds -- in addition to the most recent, I believe it was David
Sibley over a decade ago, and Marshall Iliff this year.  I was one of the
discoverers of the bird and it was certainly a Little Gull, of which I
have seen hundreds.  I have multiple photos of the bird and these were
sent to David Sibley (if my memory is correct) and of course he agreed
with the ID as Little Gull.

The only problem lies in the fact that the single photo used in American
Birds is a bit misleading and indeed shows incorrectly what the bird
really looked like. -- but it's great that people continue to study old
photos!

Alan Wormington,
Leamington, Ontario

On Thu, 14 Dec 2000 19:11:51 EST Matt Hafner <MH1920(AT)AOL.COM> writes:
> Hello all,
>
> I'm a teen birder and interested in learning more about bird
> identification.  I've spent some time looking through old American
> Birds/Field Notes to further my knowledge.  I read through the field
> reports and try to ID the pictures as they appear.  I feel that I've
> learned a great deal about distribution and identification by doing
> this.  However, scanning through pictures has made me ask some
> questions.  The particular bird I would like to ask about in this
> message can be seen in the May 1979 issue of American Birds on page
> 276.  It is a small gull taken in Ft. Pierce Harbor, FL on Jan. 14,
> 1979 by Alan Wormington.
>
> I would be interested to know the field marks that make this gull a
> Little Gull (Larus minutus).  My first impression of the bird was
> that is appeared to be a Ross's Gull (Rhodostethia rosea).  The
> field marks that jumped out at me were the clean white cap, doe eye,
> and the short, petite bill.  Other field marks that led me to Ross's
> were the primary pattern and overall structure.  The primaries
> appear to have white inside linings as opposed to being completely
> black.  The primaries also appear rather long and the crown peaked.
> My overall first impression of the bird was that it was a Ross's
> Gull.
>
> I have never seen a Ross's, and have only seen about 10-12 Little
> Gulls.  That is why I am asking for input as to what makes this bird
> a Little Gull.  I would not like to mistake a Little Gull as my life
> Ross's Gull.  The main question seems to be: Can Little Gull show a
> pale and peaked crown as this bird does?  Also, can Little Gull show
> this type of primary pattern?  I have not found a source that says
> so, but perhaps someone on this list has more experience.  Thank you
> in advance for any information you can provide.
>
>
> Matt Hafner
> University of Maryland, College Park


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Subject: American Birds photo
From: Andrew Kratter <kratter(AT)FLMNH.UFL.EDU>
Date: 16 Dec 2000 9:57am

Alan et al.
I know you are probably right, but WHY is this a Little Gull?  Your message
does nothing to contradict what Matt stated and what I can see in the
photo: which is a big-eyed, white capped 1st winter gull with an awful lot
of white in the inner primaries, which makes it look a lot like a Ross'.
Those with great experience have been proven wrong before...

Andy
Andrew W. Kratter
Collections Manager, Ornithology
Florida Museum of Natural History
PO Box 117800
University of Florida
Gainesville, FL 32611

phone 352-392-3293
fax 352-846-0287


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Subject: Re: American Birds 'Little Gull' photo
From: Bill or Sue Smith <birdsmiths(AT)hotmail.com>
Date: 16 Dec 2000 1:16pm

    FWIW, I have a crystal-clear memory of this incident, and the story may
be worth retelling.

    I may have been the only person who picked up on this photo when it was
published in mid-1979.  I had an exchange with the regional and subregional
editors of AB at the time.  The subregional editor in particular, who was
one of those who saw the bird, was incensed that I should question the
bird's identification as Little rather than Ross's.

    I let the matter pass until the Sept. 1979 WFO field trip off San
Diego, when I brought it up during a bull session on possibly
mis-identified photos.  Guy McCaskie was sufficiently intrigued that he
later studied the published photo in great detail and wrote a
widely-circulated, several-page analysis as to why the bird was surely a
Ross's, not a Little.

    His letter unleashed "the rest of the story".  Apparently Alan
Wormington took several photos of the Florida gull, all of which were
submitted to the AB subregional editor.  The group of photos was passed up
the chain-of-command finally to the AB staff in New York, who chose the
photo actually published.  They chose the photo that was sharpest, without
considering what it looked like.  When the entire group of photos was
passed along by Alan to Guy, myself, and others, we all agreed that the
other photos clearly showed a Little Gull, not a Ross's.

    Whether the published photo is a truly misleading image of the Little
Gull in Florida, or a mislabelled photo of a Ross's from elsewhere taken at
another time, possibly even by someone else, is an issue only Alan can
address.  There is no question from the rest of the evidence that the bird
actually present in Florida that winter was a Little.

    I suppose the moral of this story is: never let someone choose a photo
of a rarity to be published who is far-removed from the matter itself :-)

Bill
-----------------
The Smiths
Grays Harbor, Washington USA
birdsmiths(AT)hotmail.com


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Subject: Kelp Gulls in the Caribbean
From: "Robert H. Lewis" <lewis(AT)BWAY.NET>
Date: 16 Dec 2000 6:54pm

Hi again,

  Well, the hits just keep on coming...

  Due to Floyd Hayes and Martin Frost, I have added thirteen photos of Kelp
Gulls on Trinidad and Barbados to my web site.  These latest additions are
at

http://www.bway.net/~lewis/birds/trind/trindk.html

  Relevant to the hybrid question, I will soon have some new photos posted
from that amazing Connecticut photographer, Patrick Comins, of presumed
(probable?) hybrid Lesser X Herring.  Stay tuned!!! (now where have I seen
that before....)

Bob Lewis
Sleepy Hollow NY
http://www.bway.net/~lewis/birds/gulls.html