ID-FRONTIERS for March 23-31, 2003

Messages are displayed in the order they were received.  Subject  From  Date   Time   VA Beach Gull   Nick Rossiter    Sun, 23 Mar 2003   2:56am   RFH: a white-winged - type gull   Martin Reid    Sun, 23 Mar 2003   4:06am   Great Gulls!   Norman D.van Swelm   Sun, 23 Mar 2003   6:27am   Kumlien's-Thayer's Gulls in Toronto   Jean Iron    Sun, 23 Mar 2003   4:05pm   Re: Great gulls   Peter Adriaens    Mon, 24 Mar 2003   3:41am   Re: Great gulls   Bert-Jan Luijendijk    Mon, 24 Mar 2003   8:08am   Kumlien's subadults from Milwaukee   Brian Boldt    Mon, 24 Mar 2003   11:27am   Identification of the forms of Greater White-fronted Goose   Martin Reid    Tue, 25 Mar 2003   7:10pm   TR : annonce pour hybridation?   =?iso-8859-1?Q?Pierr   Wed, 26 Mar 2003   2:59am   Great gull!   Norman D.van Swelm   Thu, 27 Mar 2003   3:18pm   RE : Great Gulls!   =?iso-8859-1?Q?Pierr   Fri, 28 Mar 2003   9:46am   Re: Great Gulls!   Norman D.van Swelm   Sat, 29 Mar 2003   5:03pm   Mystery herons in Australia   Floyd Hayes    Sun, 30 Mar 2003   7:21am

To use email addresses replace '(AT)' with '@'. This is done to confuse the spam 'bots.

[ << | >> | ^^ ]

Subject: VA Beach Gull
From: Nick Rossiter <nrossiter(AT)SUPANET.COM>
Date: 23 Mar 2003 2:56am

This is a multi-part message in MIME format.

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

For those looking fior the most recent information on 'cantabricans' =
YLG, some detail may be found in Pierre Y=E9sou's paper in Dutch Birding =
'Trends in Systematics' in 2002 -- 24(5) p.288 and p.298. This gives =
citations to earlier work by Devillers, Teyss=E8dre (who found through =
sonograms that the calls were very similar to argenteus), Carrera, =
Dubois, Beaubrun and Garner. Taxonomic note 8 is interesting -- we =
perhaps should be calling this taxon bernisi. Some web references were =
given in my last message.=20

Regards ... Nick

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


[ << | >> | ^^ ]

Subject: RFH: a white-winged - type gull
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 23 Mar 2003 4:06am

Dear all,
Given the recent spate of emails on the topic of
thayeri/kumlieni/glaucoides ID and status, I'd like to request feedback on
this bird:
http://members.tripod.com/~tbrc/oops.htm
  - it was near High Island, TX on April 21, 1991, and seen only by a
handful of birders.  It was submitted as thayeri, and the field notes
stated that the dark pigment in the folded wings was black.  When I saw the
photos for the first time (many years later) I was surprised to see the
primary pattern therein.  the bird was described as having a darkish eye
and brownish-purple orbital ring, and (I think) to have been smaller than
one 1B HERG nearby.  Despite the rather bulky appearance, a couple of
experienced birders from within the main wintering range of kumlieni had
commented that this bird would not stand out in their winter flocks of that
taxon.
Does this bird fit into the "grey-winged thayeri" type recently mentioned
in IDF posts?
Cheers,
Martin

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


[ << | >> | ^^ ]

Subject: Great Gulls!
From: "Norman D.van Swelm" <Norman.vanswelm(AT)WXS.NL>
Date: 23 Mar 2003 6:27am

Two weeks ago Martin Reid was so kind as to made available to you some
pictures of gulls I made last November at:

  http://www.martinreid.com/gullsp32.html

Since then many of you have responded to me privately and hereunder I
summarise your views.

Gull a
photographed late afternoon of 4th November 2002 at the Brouwersdam, SW
Netherlands (51.45N 03.50N)
None of the respondents came up with a credible answer;

Gull b
photographed in the early morning of 5th November 2002 at Westkapelle, SW
Netherlands (51.32N 03.26E).
All but one respondent suggested hybrid Larus hyperboreus x Larus
argentatus. One respondant suggested Larus hyperboreus x Larus marinus.
Interestingly the first suggestion came from North American and European
respondents alike.

Gull c
photographed late afternoon of 4th November 2002 at the Brouwersdam, SW
Netherlands (51.45N 03.50N)
All respondents suggested Larus argentatus argentatus, the Herring Gull that
breeds in N.Norway and N.Russia along the Barentsz Sea.
.
Clearly Gull a is the real problem. Just look again at this stunning bird
and try to figure out it's age. There is no European gull that has this
combination of feather generations and none has ever a dark band formed by
the greater coverts like this bird has The freshest mantle feathers have a
black centre suggesting that when the bird has finished this moult the
mantle will be black. If it were to be a European bird you would guess it to
be a 1st or 2nd winter bird but it does not fit. And no wonder. This is a
bird from the Southern Hemisphere. It is less than a year old, it has
retained juvenile covers but look at the greater coverts forming the dark
band, two generations here! In conventional terminology I guess we would age
this as 1st summer moulting towards 2nd winter!

I think the dark greater covert band is diagnostic for Kelp. Have a look at
plate 13, page 117, Birding World vol 14, no 3., the bird portrayed there
also has an identical tertial pattern.
Kelp is a new gull for Europe. I know of an adult seen in Danmark by a gull
expert who was alone and therefore refrained from making it public. I myself
have doubts about an adult photographed by me in a severe storm some years
ago and now there is gull a for all to see!
Norman


[ << | >> | ^^ ]

Subject: Kumlien's-Thayer's Gulls in Toronto
From: Jean Iron <jeaniron(AT)SYMPATICO.CA>
Date: 23 Mar 2003 4:05pm

Dear ID-Frontiers,

Please see photos of Kumlien's-Thayer's type gulls that I photographed this
winter in Toronto, Ontario. They show only a sample of the wide variation
in the Iceland Gull complex seen on Lake Ontario.

http://ca.photos.yahoo.com/bc/jeaniron2/lst?.dir=/2nd+Iceland+Gull+Variation+in+Toronto&.view=t

http://ca.photos.yahoo.com/bc/jeaniron2/lst?.dir=/Iceland+Gull+Variation+in+Toronto&.src=ph&.view=

Jean Iron
President
Ontario Field Ornithologists
9 Lichen Place
Toronto ON  M3A 1X3
416-445-9297
e-mail: jeaniron(AT)sympatico.ca
www.ofo.ca


[ << | >> | ^^ ]

Subject: Re: Great gulls
From: Peter Adriaens <peter.adriaens(AT)DUTCHBIRDING.NL>
Date: 24 Mar 2003 3:41am

Hi,
just a few preliminary thoughts on this interesting 'gull A':
I agree that it is a first summer bird moulting to second winter, but it seems
to be
nearing the end of its complete moult (as a side-thought, should a Kelp Gull not
 be
just starting its moult at that time of the year?). It already has 8 new
primaries; p9-10
are still growing.
There is a lot of moult going on in the wingcoverts. In fact, could it not be
possible
that an entire row of old greater coverts is missing, and that those are the
secondaries we are looking at, instead of "diagnostically dark greater
coverts"?
What are the possibilities of this being a Great Black-backed Gull that, for
some
reason (sickness?), shows a very protracted/retarded moult? Can you really
discount that option?
Kind regards,
Peter


[ << | >> | ^^ ]

Subject: Re: Great gulls
From: Bert-Jan Luijendijk <bjluijendijk(AT)PLANET.NL>
Date: 24 Mar 2003 8:08am

Dear Peter,

> There is a lot of moult going on in the wingcoverts. In fact, could it not
be possible
> that an entire row of old greater coverts is missing, and that those are
the
> secondaries we are looking at, instead of "diagnostically dark greater
coverts"?

In terms of moult sequence it would be illogical that bird A is missing its
entire row of greater coverts, since it means that this bird will complete
the moult of the secondaries earlier than the moult of the greater coverts.
Most large gulls occuring in Europe finish the moult of the secondaries 1-2
months later than the moult of the greater coverts. In my opinion this bird
has still very fresh greater coverts (apart from the inner ones), while it
is possibly still regrowing its central greater coverts (which would be
consistent with the normal moult sequence of European large gull taxa). As a
rule, newly attained upperwingcoverts initially have a rather dark and plain
appearance, which will fade and become more clearly patterned as the age of
the feather progresses.

> What are the possibilities of this being a Great Black-backed Gull that,
for some
> reason (sickness?), shows a very protracted/retarded moult? Can you really
> discount that option?

I also think we are dealing with a 2nd cy GBBG which is in the final stage
of the complete moult and I don't think that we should pay very much
attention to the fact that its moultpace and/or timing appears to be
somewhat different from the vast majority as I have seen few individuals
with an equivalent moultstage (in the Netherlands at the same time).
As Norman seems to disagree with an identification as GBBG, I am very
interested in his opinion on the identification of this bird (rather than
his opinion on the credibility of the answers he has received sofar).

Cheers,

Bert-Jan Luijendijk


[ << | >> | ^^ ]

Subject: Kumlien's subadults from Milwaukee
From: Brian Boldt <bboldt(AT)EXCELCOMM.COM>
Date: 24 Mar 2003 11:27am

Not that this pot needs more stirring, but...

Since most of the discussion thus far has concerned adults, I wanted to post
a sampling of some of the sub-adults we get on Lake Michigan before this
thread ran it's course, with some brief comments. Note that these photos are
posted under either Iceland (Kumlien's) or Thayer's categories on my site
because I've not yet had time to develop a page devoted specifically to the
ambiguity of some identifications.

Here we've generally taken the approach that, assuming Kumlien's is a hybrid
swarm as previously mentioned, a bird having one or more characteristics
atypical of Thayer's is likely by definition a Kumlien's; of course, one
always looks for a suite of characteristics, e.g. small & rounded head.
thin/short bill, mottled tertials, lack of strong secondary bar, lack of
dark coalesence around eye, broken tail band . Judging by the skepticism
accorded many Pacific Coast Kumlien's records however, I imagine many there
would argue Thayer's for some of the birds we here would call Kumlien's. On
the other hand, on the east coast Thayer's is the tougher call (see this
Delaware bird: http://www.udel.edu/dosbirds/photogallery/thayers.htm) I
wonder if any of this seemingly clinal variation will ever be tied to
specific breeding colonies? In Milwaukee we see more birds we call Thayer's
than Kumliens, and the majority that we call Thayer's are a much more
homogeneous bunch than the minority we call Kumlien's. Additionally, the
Thayer's seem to arrive at least a month ahead of the Kumlien's.

Kumlien's:

2nd Basic, mottled tertials, but largely dark primaries, mantle shade seems
lighter than Herring:
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=132
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=131

1st basic, short yet thick bill, primaries mostly white, tertials solid
centered near the base:
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=139

1st basic, tertials pale, some brown in primaries, smaller headed and
smaller billed:
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=62

2nd basic, structurally like Kumlein's, mottled tertials, largely brown
primaries
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=74

2nd basic, mottled tertials, white primary edges broad for typical Thayer's,
small headed and small billed:
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=149

1st basic, pale overall and pale tertials, but head and bill structure more
suggestive of Thayer's (faded late winter Thayer's?):
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=148

1st or 2nd basic, pale extreme for Lake Michigan, bill suggesting 2nd basic,
but no gray "saddle"
http://birds.excelcomm.com/gullpage/pic.asp?id=ICGU&pid=145

2nd basic, more typically Kumlien's than some of these others, strongly
mottled tertials, mostly white primaries, light iris
http://birds.excelcomm.com/winthrop/icgu_15Feb03_b2c.jpg
http://birds.excelcomm.com/winthrop/icgu_15Feb03_b2a.jpg

Thayer's:

1st basic, typical Thayer's, with tertial mottling restricted to the very
tips:
http://birds.excelcomm.com/gullpage/pic.asp?id=THGU&pid=116
http://birds.excelcomm.com/gullpage/pic.asp?id=THGU&pid=118

Brian Boldt / Milwaukee


[ << | >> | ^^ ]

Subject: Identification of the forms of Greater
         White-fronted Goose
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 25 Mar 2003 7:10pm

Dear all,
I've built a page to address the subspecific ID of GWGO; it's a
work-in-progress and I'd appreciate getting feedback - thanks:
http://www.martinreid.com/gwgo.html
Martin

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


[ << | >> | ^^ ]

Subject: TR : annonce pour hybridation?
From: =?iso-8859-1?Q?Pierre-Andr=E9_CROCHET?= <crochet(AT)CEFE.CNRS-MOP.FR>
Date: 26 Mar 2003 2:59am

This is a multi-part message in MIME format.

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

Pierre-Andr=E9 Crochet
CEFE-CNRS
1919, route de Mende
34293 Montpellier cedex 5
France
tel: + 33 6 07 32 60 75
fax: + 33 4 67 41 21 38
crochet(AT)cefe.cnrs-mop.fr

-----Message d'origine-----
De : Laurene GAY=20
Envoy=E9 : jeudi 13 mars 2003 11:00
=C0 : Pierre-Andr=E9 CROCHET
Objet : annonce pour hybridation?

Dear all,

I am forwarding a message from my PhD student. She is starting to work =
on hybridisations in large white-headed gulls.

Please fell free to contact us for any additional information.

Pierre-Andr=E9 Crochet

=20

Dear gull people,
I am currently a PhD student in Montpellier, working on the evolutionary =
consequences of hybridisation and natural selection among large =
white-headed gulls under the supervision of P.A. Crochet, J.D. Lebreton =
and P. Jarne.=20

In order to clarify the frequency of hybridisation among large =
white-headed gulls and to search for some general patterns, I would like =
to gather information about mixed pairs observed in the field.=20

What we would like to know is 1) precise locality 2) the parental =
species with SPECIES ID OF EACH SEX if possible (this is important) 3) =
number of offspring (if observed). If some individuals are ringed, =
please specify the number.=20

Furthermore, it is actually very difficult to prove that offsprings of a =
mixed pair are actually hybrids (due to the risk of extra pair =
copulation by the female). So whenever possible, try catching the chicks =
and sample a few feathers for DNA analyses.=20
The best, when possible, would be to catch and sample both parents and =
the offsprings.

Last, we are also interested in all information (unpublished as well as =
previsouly publihed) regarding large gulls identified as hybrids, =
especially information on the frequency of suspected hybrids relative to =
pure birds in any locality. Again, catching and sampling feathers from =
any suspected hybrid would be of immense interest.

Thanks a lot in advance if you can help,

All contributors will be acknowledged in publications and will receive =
copies of the papers.

Laur=E8ne GAY
PhD student in Evolutionary Biology and Ecology
c/o P.A. Crochet, J.D. Lebreton and P. Jarne=20

CEFE-CNRS
1919 route de Mende=20
34293 Montpellier cedex 5
France
T=E9l : 00 33 4-67-61-32-98=20
Fax : 00 33 4-67-41-21-38=20
laurene.gay(AT)cefe.cnrs-mop.fr

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


[ << | >> | ^^ ]

Subject: Great gull!
From: "Norman D.van Swelm" <Norman.vanswelm(AT)WXS.NL>
Date: 27 Mar 2003 3:18pm

Bert-Jan Luijendijk wrote:> As Norman seems to disagree with an
identification as GBBG, I am very
> interested in his opinion on the identification of this bird (rather than
> his opinion on the credibility of the answers he has received sofar).<

It is understandable that a European observer considers a bird like gull a
almost automatically as a Great Black-backed Gull since L.marinus is the
only European gull with a big bill like gull a! However anyone who has
studied L.marinus knows that a plumage like that of gull a is unknown in
L.marinus. Even in it's third winter L.marinus does not have a dark band
formed by the greater coverts as gull a has. By now Bert-Jan you may have
seen the excellent story on Kelp Gulls in Birding World I mentioned and if
so, you will have seen that this dark greater covert band is typical for
Kelp Gull. It may interest you too that gull a was not bigger than an
average Herring Gull, quite a bit smaller than the smallest female
L.marinus.
Norman


[ << | >> | ^^ ]

Subject: RE : Great Gulls!
From: =?iso-8859-1?Q?Pierre-Andr=E9_CROCHET?= <crochet(AT)CEFE.CNRS-MOP.FR>
Date: 28 Mar 2003 9:46am

Dear all,

I have forwarded the picture of "Gull a" to Frederic Jiguet, who commented as
follows:

"Plumage could fit but tarsi are pink, without brown, which I think excludes
Kelp Gull. Furthermore, primaries seem to be moulting, which prevents judging
from structure".

Hope this helps....

Pierre-André Crochet
CEFE-CNRS
1919, route de Mende
34293 Montpellier cedex 5
France
tel: + 33 6 07 32 60 75
fax: + 33 4 67 41 21 38
crochet(AT)cefe.cnrs-mop.fr

-----Message d'origine-----
De : Norman D.van Swelm [mailto:Norman.vanswelm(AT)WXS.NL]
Envoyé : dimanche 23 mars 2003 14:23
À : BIRDWG01(AT)listserv.arizona.edu
Objet : [BIRDWG01] Great Gulls!

Two weeks ago Martin Reid was so kind as to made available to you some
pictures of gulls I made last November at:

  http://www.martinreid.com/gullsp32.html

Since then many of you have responded to me privately and hereunder I
summarise your views.

Gull a
photographed late afternoon of 4th November 2002 at the Brouwersdam, SW
Netherlands (51.45N 03.50N)
None of the respondents came up with a credible answer;

Gull b
photographed in the early morning of 5th November 2002 at Westkapelle, SW
Netherlands (51.32N 03.26E).
All but one respondent suggested hybrid Larus hyperboreus x Larus
argentatus. One respondant suggested Larus hyperboreus x Larus marinus.
Interestingly the first suggestion came from North American and European
respondents alike.

Gull c
photographed late afternoon of 4th November 2002 at the Brouwersdam, SW
Netherlands (51.45N 03.50N)
All respondents suggested Larus argentatus argentatus, the Herring Gull that
breeds in N.Norway and N.Russia along the Barentsz Sea.
.
Clearly Gull a is the real problem. Just look again at this stunning bird
and try to figure out it's age. There is no European gull that has this
combination of feather generations and none has ever a dark band formed by
the greater coverts like this bird has The freshest mantle feathers have a
black centre suggesting that when the bird has finished this moult the
mantle will be black. If it were to be a European bird you would guess it to
be a 1st or 2nd winter bird but it does not fit. And no wonder. This is a
bird from the Southern Hemisphere. It is less than a year old, it has
retained juvenile covers but look at the greater coverts forming the dark
band, two generations here! In conventional terminology I guess we would age
this as 1st summer moulting towards 2nd winter!

I think the dark greater covert band is diagnostic for Kelp. Have a look at
plate 13, page 117, Birding World vol 14, no 3., the bird portrayed there
also has an identical tertial pattern.
Kelp is a new gull for Europe. I know of an adult seen in Danmark by a gull
expert who was alone and therefore refrained from making it public. I myself
have doubts about an adult photographed by me in a severe storm some years
ago and now there is gull a for all to see!
Norman


[ << | >> | ^^ ]

Subject: Re: Great Gulls!
From: "Norman D.van Swelm" <Norman.vanswelm(AT)WXS.NL>
Date: 29 Mar 2003 5:03pm

Pierre-André Crochet wrote:> I have forwarded the picture of "Gull a" to
Frederic Jiguet, who commented as follows:
>
> "Plumage could fit but tarsi are pink, without brown, which I think
excludes Kelp Gull. Furthermore, primaries seem to be moulting, which
prevents judging from structure".<

The remarks made by Frederic Jiguet (who is one of the authors of the
Birding World article, see below) about the tarsi colour of "gull a" see
http://www.martinreid.com/gullsp32.html  is very interesting. Most juvenile
gulls have dark legs, remnants of which remain especcially on the shins for
some time after fledging. They are barely visible in young Herring Gulls
L.a.argenteus and lost almost entirely in L.michahellis two months or less
after fledging. In dark species such as L.fuscus darkish shins remain a bit
longer. As far as young Kelp Gull is concerned not much information is
available but Jiguet et al state on page 118: 'The legs are sometimes pink,
smudged with dark grey or brown, but are sometimes entirely greyish-brown.'.
However when one studies Jiguet's photo's of juveniles taken on Crozet
Island in the Indian Ocean (plate 2 and 5 page 116, Birding World vol 14, no
3., the birds portrayed there have indeed very dark brown tarsi. Even the
tarsi of a second winter gull from Crozet photographed in April (plate 14)
are still pretty brown but then it seems young Kelp Gulls from Crozet are on
the whole a lot darker than those from other regions. Clearly tarsi colour
in young Kelp Gulls is variable. A juvenile of the race vetula photographed
in February in Cape Town (plate 6) has pale pink tarsi and pale brown edges
to the shin scales whereas an immature from Cape Town moulting to second
winter and photographed in February (plate 11) still has very dark tarsi
while another second winter from February (plate 12) has pale pink tarsi!
"Gull a", photographed in The Netherlands in the beginning of November has
similar coloured tarsi as the bird in plate 12 and still has faint brownish
edges to the shin scales!
Norman


[ << | >> | ^^ ]

Subject: Mystery herons in Australia
From: Floyd Hayes <floyd_hayes(AT)YAHOO.COM>
Date: 30 Mar 2003 7:21am

Niven McCrie would appreciate receiving opinions on
the identity of some 'mystery herons' from northern
Australia posted at:

http://www.users.bigpond.com/birdsnt/herons.htm

Please send your opinions to Niven at:
nivenmccrie(AT)bigpond.com

-Floyd

__________________________________________________
Do you Yahoo!?
Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
http://platinum.yahoo.com