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ID-FRONTIERS for June 21-30, 2009
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Messages are displayed in the order they were received.
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| Subject | From | Date | Time |
| Re: asymmetrical Lesser Black-backed Gull | Floyd Hayes | Mon, 22 Jun 2009 | 11:37am |
| Franklin's or Laughing Gull? | =?windows-1252?Q?Dan | Mon, 22 Jun 2009 | 5:49pm |
| Re: Franklin's or Laughing Gull? | Julian Hough | Mon, 22 Jun 2009 | 6:41pm |
| FRANKLIN'S GULL | Lee G R Evans | Tue, 23 Jun 2009 | 1:49am |
| Re: FRANKLIN'S GULL | Tony Leukering | Tue, 23 Jun 2009 | 5:15am |
| Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Norman D.van Swelm | Thu, 25 Jun 2009 | 4:56am |
| Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Alvaro Jaramillo | Thu, 25 Jun 2009 | 9:27am |
| Asymmetrical gull | Michael F | Thu, 25 Jun 2009 | 9:54am |
| Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Peter Pyle | Thu, 25 Jun 2009 | 10:28am |
| Unidentified Catharus thrush | Peter Pyle | Thu, 25 Jun 2009 | 11:58am |
| Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Norman D.van Swelm | Thu, 25 Jun 2009 | 2:45pm |
| Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Norman D.van Swelm | Thu, 25 Jun 2009 | 3:28pm |
| Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Kevin Karlson | Thu, 25 Jun 2009 | 3:52pm |
| Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well? | Norman D.van Swelm | Fri, 26 Jun 2009 | 5:02am |
| Re: Unidentified Catharus thrush | Peter Pyle | Fri, 26 Jun 2009 | 10:56am |
|
To use email addresses replace '(AT)' with '@'.
This is done to confuse the spam 'bots.
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[ << | >> | ^^ ]
Subject: Re: asymmetrical Lesser Black-backed Gull
From: Floyd Hayes <floyd_hayes(AT)YAHOO.COM>
Date: 22 Jun 2009 11:37am
It's called heterochromia but there appears to be very little published on the
subject for birds. Most reports refer to heterochromia iridis, which refers to
different colored eyes. It's rather widespread in mammals. I've encountered only
a few published reports in birds. Here's an example of a Ring-billed Gull
photographed earlier this year with heterochromia in both the eyes and legs:
http://www.flickr.com/photos/floyd_hayes
Did your Lesser Black-backed Gull have different colored eyes as well?
Floyd Hayes
Hidden Valley Lake, CA
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Subject: Franklin's or Laughing Gull?
From: =?windows-1252?Q?Daniel_Jones?= <antshrike1(AT)AOL.COM>
Date: 22 Jun 2009 5:49pm
I found this gull on 6/20/09 at a pond near Hargill, Hidalgo county,
Texas. It has generated quite a bit of discussion on TEXBIRDS with a small
majority leaning towards Franklin's Gull. Comments?
http://i40.tinypic.com/13z3k37.jpg
http://i41.tinypic.com/v7y1w5.jpg
http://i41.tinypic.com/14b5oyc.jpg
http://i39.tinypic.com/2419ijq.jpg
http://i40.tinypic.com/cp2pz.jpg
http://i39.tinypic.com/rvbwqq.jpg
Dan Jones in Weslaco, TX
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Subject: Re: Franklin's or Laughing Gull?
From: Julian Hough <jrhough1(AT)SNET.NET>
Date: 22 Jun 2009 6:41pm
Dan,
I agree with your consensus that it's a Franklin's Gull..finishing it's
complete 'spring' moult out of first-basic/first-winter plumage.
Aside from the head pattern, other good pro-Franklin's features are the pale
grey inner primaries (not shown by Laughing Gull at this age) and the
basically all white-tail, lacking a black tailband, which is unique among
gulls at this age.
Best,
Julian Hough,
CT, USA
jrhough1(AT)snet.net
www.naturescapeimages.net
----- Original Message -----
From: "Daniel Jones" <antshrike1(AT)AOL.COM>
To: <BIRDWG01(AT)LISTSERV.ARIZONA.EDU>
Sent: Monday, June 22, 2009 8:39 PM
Subject: [BIRDWG01] Franklin's or Laughing Gull?
I found this gull on 6/20/09 at a pond near Hargill, Hidalgo county,
Texas. It has generated quite a bit of discussion on TEXBIRDS with a small
majority leaning towards Franklin's Gull. Comments?
http://i40.tinypic.com/13z3k37.jpg
http://i41.tinypic.com/v7y1w5.jpg
http://i41.tinypic.com/14b5oyc.jpg
http://i39.tinypic.com/2419ijq.jpg
http://i40.tinypic.com/cp2pz.jpg
http://i39.tinypic.com/rvbwqq.jpg
Dan Jones in Weslaco, TX
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Subject: FRANKLIN'S GULL
From: Lee G R Evans <LGREUK400(AT)AOL.COM>
Date: 23 Jun 2009 1:49am
----INCLUDING text/plain MIME SECTION----
Totally agree with Julian that this individual best fits first-summer
FRANKLIN'S GULL. In most images, the bill is seen to be short and rather stubby
unlike the long drooping bill of Laughing and the underparts are all
gleaming white (first-year Laughing Gulls tend to have quite dark grey breast
bands or fore-flanks). I cannot explain the long leg length though; Franklin's
Gull has relatively short tibia. Certainly an intriguing bird
Best wishes
Lee G R Evans
British Birding Association
UK400 Club, Rare Birds Magazine, Ornithological Consultant and
Conservationist
Discussion Forum/Email Group: _http://groups.yahoo.com/group/UK400Club/_
(http://groups.yahoo.com/group/UK400Club/)
Rare Bird Alert:
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(http://groups.yahoo.com/group/RareBirdAlertforBritainandIreland_UK400ClubBBA/)
Email Address: LGREUK400(AT)aol.com
Website Address: _www.uk400clubonline.co.uk_
(http://www.uk400clubonline.co.uk/)
Blog Sites: _http://uk400clubrarebirdalert.blogspot.com/_
(http://uk400clubrarebirdalert.blogspot.com/) _
http://birdingamersham.blogspot.com/_
(http://birdingamersham.blogspot.com/) _
http://birdingtringreservoirs.blogspot.com/_
(http://birdingtringreservoirs.blogspot.com/)
_http://calvertbirding.blogspot.com/_ (http://calvertbirding.blogspot.com/)
Chaffinch House
8 Sandycroft Road
Little Chalfont
Amersham
Buckinghamshire
England
HP6 6QL
Telephones: 01494 763010 and 01494 581157
Mobile/Text Alerts: 07881 906629
(Lee Evans Enterprises incorporate documentation of rare bird occurrences
in Britain & Ireland and elsewhere in the Western Palearctic and in North
America; Rare Bird Information and Rare Bird Alerts; Rare Birds Magazine and
other related publications; Bird Tours for Birders)
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Subject: Re: FRANKLIN'S GULL
From: Tony Leukering <greatgrayowl(AT)AOL.COM>
Date: 23 Jun 2009 5:15am
--Apple-Mail-1--983395064
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charset=us-ascii;
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Additionally, Laughing never has such large white primary tips as the
one that the pictured birds shows.
Tony Leukering
Villas, NJ
Sent from my iPhone
On Jun 23, 2009, at 4:49 AM, Lee G R Evans <LGREUK400(AT)AOL.COM> wrote:
> Totally agree with Julian that this individual best fits first-
> summer FRANKLIN'S GULL. In most images, the bill is seen to be short
> and rather stubby unlike the long drooping bill of Laughing and the
> underparts are all gleaming white (first-year Laughing Gulls tend to
> have quite dark grey breast bands or fore-flanks). I cannot explain
> the long leg length though; Franklin's Gull has relatively short
> tibia. Certainly an intriguing bird
>
> Best wishes
>
>
> Lee G R Evans
> British Birding Association
> UK400 Club, Rare Birds Magazine, Ornithological Consultant and
> Conservationist
> Discussion Forum/Email Group: http://groups.yahoo.com/group/UK400Club/
> Rare Bird Alert:
http://groups.yahoo.com/group/RareBirdAlertforBritainandIreland_UK400ClubBBA/
> Email Address: LGREUK400(AT)aol.com
> Website Address: www.uk400clubonline.co.uk
> Blog Sites: http://uk400clubrarebirdalert.blogspot.com/
http://birdingamersham.blogspot.com/
> http://birdingtringreservoirs.blogspot.com/
> http://calvertbirding.blogspot.com/
>
> Chaffinch House
> 8 Sandycroft Road
> Little Chalfont
> Amersham
> Buckinghamshire
> England
> HP6 6QL
>
> Telephones: 01494 763010 and 01494 581157
> Mobile/Text Alerts: 07881 906629
>
> (Lee Evans Enterprises incorporate documentation of rare bird
> occurrences in Britain & Ireland and elsewhere in the Western
> Palearctic and in North America; Rare Bird Information and Rare Bird
> Alerts; Rare Birds Magazine and other related publications; Bird
> Tours for Birders)
> Join or Leave BIRDWG01:
http://listserv.arizona.edu/cgi-bin/wa?SUBED1=birdwg01
>
> Archives: http://listserv.arizona.edu/archives/birdwg01.html
>
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[ << | >> | ^^ ]
Subject: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: "Norman D.van Swelm" <Norman.vanswelm(AT)wxs.nl>
Date: 25 Jun 2009 4:56am
Have a look here please:
http://www.radioactiverobins.com/snipes-waders/sanderlings%20in%20a%20storm.htm
and share your opinion with all of us.
Cheers, Norman
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Subject: Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: Alvaro Jaramillo <chucao(AT)COASTSIDE.NET>
Date: 25 Jun 2009 9:27am
Norman
My guess is that outside of the bright males, one has no hope of
separating the greyish females and first spring birds. But with males, I can
see differences between photos from Europe and the birds I see here in
California. Restricting to birds that have lots of rufous on the face in May
(so the brightest birds) our birds are grizzled with grey tips from the nape
all the way through the upperparts. While they are clearly rufous birds,
they look peppered with "snow" a look that I do not see on the much more
solidly rufous Euro birds. It would be interesting to find out if that
general look is also what they see on the North American Atlantic Coast.
Cheers,
Alvaro
Alvaro Jaramillo
chucao(AT)coastside.net
Half Moon Bay, California
Field Guides - Birding Tours Worldwide
www.fieldguides.com
-----Original Message-----
From: NBHC ID-FRONTIERS Frontiers of Field Identification
[mailto:BIRDWG01(AT)LISTSERV.ARIZONA.EDU] On Behalf Of Norman D.van Swelm
Sent: Thursday, June 25, 2009 4:56 AM
To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
Subject: [BIRDWG01] Do Canadian Sanderlings Calidris a. rubidus migrate to
and from Europe as well?
Have a look here please:
http://www.radioactiverobins.com/snipes-waders/sanderlings%20in%20a%20storm.
htm
and share your opinion with all of us.
Cheers, Norman
Join or Leave BIRDWG01:
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Subject: Asymmetrical gull
From: Michael F <whitethro(AT)GOOGLEMAIL.COM>
Date: 25 Jun 2009 9:54am
--0016e659f8c8c28753046d2ef044
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Just to throw something else into the mix, in February I found an
asymmetrical leucistic Herring Gull on the Thames.
http://countingcoots.blogspot.com/2009/02/another-funny-looking-gull.html
I cannot, however, vouch for the eye colour...
Cheers,
Michael
--
http://countingcoots.blogspot.com/
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--0016e659f8c8c28753046d2ef044
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<div>Just to throw something else into the mix, in February=A0I found an as=
ymmetrical leucistic Herring Gull on the Thames.</div>
<div>=A0</div>
<div><a onclick=3D"return top.js.OpenExtLink(window,event,this)" href=3D"ht=
tp://countingcoots.blogspot.com/2009/02/another-funny-looking-gull.html" ta=
rget=3D"_blank">http://countingcoots.blogspot.com/2009/02/another-funny-loo=
king-gull.html</a></div>
<div>=A0</div>
<div>I cannot, however, vouch for the eye colour...</div>
<div>=A0</div>
<div>Cheers,</div>
<div>=A0</div>
<div>Michael<br><br>=A0</div><br clear=3D"all"><br>-- <br><br><br><a onclic=
k=3D"return top.js.OpenExtLink(window,event,this)" href=3D"http://countingc=
oots.blogspot.com/" target=3D"_blank">http://countingcoots.blogspot.com/</a=
>=20
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[ << | >> | ^^ ]
Subject: Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: Peter Pyle <ppyle(AT)BIRDPOP.ORG>
Date: 25 Jun 2009 10:28am
----INCLUDING text/plain MIME SECTION----
Hello all-
Rubidus is not recognized as a valid subspecies by many, due to
mensural differences being too slight and rather substantial
individual variation in alternate plumage aspect. Wader species that
winter in both Northern and Southern Hemispheres show a lot of
variation in extent and timing of molt and I've come to wonder if
this variation rather than genetic differentiation can explain
average geographic differences in alternate plumages that we see in
some species (including Sanderling, Red Knot, and Ruddy Turnstone).
There always seem to be a few birds looking like other subspecies in
breeding populations of these. Could these be birds that simply
wintered at a different latitude than most of the population and
underwent a different hormonal-molt-pigment-deposition regime than
the others? A great topic for further research.
Peter
At 09:26 AM 6/25/2009, Alvaro Jaramillo wrote:
>Norman
>
> My guess is that outside of the bright males, one has no hope of
>separating the greyish females and first spring birds. But with males, I can
>see differences between photos from Europe and the birds I see here in
>California. Restricting to birds that have lots of rufous on the face in May
>(so the brightest birds) our birds are grizzled with grey tips from the nape
>all the way through the upperparts. While they are clearly rufous birds,
>they look peppered with "snow" a look that I do not see on the much more
>solidly rufous Euro birds. It would be interesting to find out if that
>general look is also what they see on the North American Atlantic Coast.
>
>Cheers,
>
>Alvaro
>
>Alvaro Jaramillo
>chucao(AT)coastside.net
>Half Moon Bay, California
>
>Field Guides - Birding Tours Worldwide
>www.fieldguides.com
>
>-----Original Message-----
>From: NBHC ID-FRONTIERS Frontiers of Field Identification
>[mailto:BIRDWG01(AT)LISTSERV.ARIZONA.EDU] On Behalf Of Norman D.van Swelm
>Sent: Thursday, June 25, 2009 4:56 AM
>To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
>Subject: [BIRDWG01] Do Canadian Sanderlings Calidris a. rubidus migrate to
>and from Europe as well?
>
>Have a look here please:
>
>
>http://www.radioactiverobins.com/snipes-waders/sanderlings%20in%20a%20storm.
>htm
>
>
>and share your opinion with all of us.
>Cheers, Norman
>
>
>Join or Leave BIRDWG01:
>http://listserv.arizona.edu/cgi-bin/wa?SUBED1=birdwg01
>
>Archives: http://listserv.arizona.edu/archives/birdwg01.html
>
>
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>
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[ << | >> | ^^ ]
Subject: Unidentified Catharus thrush
From: Peter Pyle <ppyle(AT)BIRDPOP.ORG>
Date: 25 Jun 2009 11:58am
----INCLUDING text/plain MIME SECTION----
Hello again-
Keith Hansen videotaped a Catharus thrush in Bolinas, central coastal
California, on 15 June 2009 that we'd like to get some opinion on.
There is general agreement that it is not of our locally breeding
Swainson's Thrush but there are some divergent opinions beyond this.
The video and some still grabs from it can be found here:
http://keithhansen.wordpress.com/
Many thanks,
Peter Pyle
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Subject: Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: "Norman D.van Swelm" <Norman.vanswelm(AT)wxs.nl>
Date: 25 Jun 2009 2:45pm
Hi Alvaro,
I wonder if any of my birds in my pictures looks like the ones you see? Do
you have or know of pictures of the birds you see in spring?
Cheers, Norman
Alvaro Jaramillo wrote: > My guess is that outside of the bright males, one
has no hope of
> separating the greyish females and first spring birds. But with males, I
> can
> see differences between photos from Europe and the birds I see here in
> California. Restricting to birds that have lots of rufous on the face in
> May
> (so the brightest birds) our birds are grizzled with grey tips from the
> nape
> all the way through the upperparts. While they are clearly rufous birds,
> they look peppered with "snow" a look that I do not see on the much more
> solidly rufous Euro birds. It would be interesting to find out if that
> general look is also what they see on the North American Atlantic Coast.
> Alvaro Jaramillo
> chucao(AT)coastside.net
> Half Moon Bay, California
> [mailto:BIRDWG01(AT)LISTSERV.ARIZONA.EDU] On Behalf Of Norman D.van Swelm
> Sent: Thursday, June 25, 2009 4:56 AM
> Have a look here please:
>
http://www.radioactiverobins.com/snipes-waders/sanderlings%20in%20a%20storm.htm
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Subject: Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: "Norman D.van Swelm" <Norman.vanswelm(AT)wxs.nl>
Date: 25 Jun 2009 3:28pm
This is a multi-part message in MIME format.
----INCLUDING text/plain MIME SECTION----
Hi Peter and all, I am aware of the fact that Rubidus has not been =
recognized by many. However, quite recently, in their unpleasantly =
scarce excellent book, Engelmoer, Meinte & Cees S.Roselaar, 1998, =
Geographical Variation in Waders, have proven that Rubides exists!=20
As for your remarks on the different timing of moult we too noticed this =
f.i. in Turnstones, the ones arriving around 1st May from Africa were in =
already bleached breeding plumage, quite distinct from the ones that =
wintered in our delta and were still in active moult at that date!=20
Cheers, Norman
Peter Pyle wrote: >Rubidus is not recognized as a valid subspecies by =
many, due to mensural differences being too slight and rather =
substantial individual variation in alternate plumage aspect. Wader =
species that winter in both Northern and Southern Hemispheres show a lot =
of variation in extent and timing of molt and I've come to wonder if =
this variation rather than genetic differentiation can explain average =
geographic differences in alternate plumages that we see in some species =
(including Sanderling, Red Knot, and Ruddy Turnstone). There always seem =
to be a few birds looking like other subspecies in breeding populations =
of these. Could these be birds that simply wintered at a different =
latitude than most of the population and underwent a different =
hormonal-molt-pigment-deposition regime than the others? A great topic =
for further research.
At 09:26 AM 6/25/2009, Alvaro Jaramillo wrote:
Norman
My guess is that outside of the bright males, one has no hope of
separating the greyish females and first spring birds. But with males, I =
can
see differences between photos from Europe and the birds I see here in
California. Restricting to birds that have lots of rufous on the face in =
May
(so the brightest birds) our birds are grizzled with grey tips from the =
nape
all the way through the upperparts. While they are clearly rufous birds,
they look peppered with "snow" a look that I do not see on the much more
solidly rufous Euro birds. It would be interesting to find out if that
general look is also what they see on the North American Atlantic Coast. =
Cheers, Alvaro
Alvaro Jaramillo
chucao(AT)coastside.net
Half Moon Bay, California
=20
Field Guides - Birding Tours Worldwide
www.fieldguides.com
Subject: [BIRDWG01] Do Canadian Sanderlings Calidris a. rubidus migrate =
to
and from Europe as well?
Have a look here please:
=20
http://www.radioactiverobins.com/snipes-waders/sanderlings%20in%20a%20sto=
rm .
htm
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Subject: Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: Kevin Karlson <karlson3(AT)COMCAST.NET>
Date: 25 Jun 2009 3:52pm
----INCLUDING text/plain MIME SECTION----
Norman and all: RE: Do Canadian Sanderlings Calidris a. rubidus migrate to =
and from Europe as well?=20
I read Norman's points with interest, but would like to address a few point=
s.=20
I have been studying Sanderlings on the Atlantic Coast near my house on Ree=
ds Beach Road near the Delaware Bay for many years. I get to see many thous=
ands of Sanderlings each year as they fatten up on Horseshoe Crab eggs prio=
r to departing for their Arctic breeding areas. Many don't leave until earl=
y June, and attain full breeding plumage by then. The incredible variety in=
plumage color, shading and intensity is hard to believe, and I often wonde=
red why only a percentage of these birds showed the 'classic' deep rust and=
black breeding plumage depicted in most popular North American field guide=
s as "breeding plumage". I eventually realized that these guides were incor=
rect in only depicting a rusty plumage condition as breeding plumage, and s=
hould have showed a variety of rust, silver and black plumage states for br=
eeding plumage.=20
When we published the Shorebird Guide, we showed a photo of three adult San=
derlings in breeding plumage, with only one having deep rust plumage color,=
and the other two showing a mix of silver and black upperpart feathers wit=
h a smattering of rust internal markings. It is now obvious that some birds=
are deep rust in breeding plumage; others are somewhat rusty, with a mix o=
f silver feathers; and others are mostly silver and black. These are adult =
birds that I am speaking of, with some first calendar year birds typically =
showing reduced rust color and variable amounts of retained juvenile wing c=
overts and flight feathers, or a mix of breeding, nonbreeding and=C2=A0juve=
nile feathers. My point is that there is really no way to say that these bi=
rds ever show a characteristic breeding plumage condition with respect to d=
epth of rust and black versus silver and black color, and I doubt that ther=
e is a reliable way to separate them from other regional populations. The d=
egree of variation in North American=C2=A0Sanderlings with respect to breed=
ing plumage color is extraordinary, and overlooked by most birders.=20
As for bill size being a determining factor for different geographical bree=
ding populations, I would think that would be hard to conclusively apply as=
well. I see a great deal of variation with length and shape of Sanderling =
bills in NJ and Florida each year. Some are short and stubby, while others =
are noticeably longer and thinner, with a slight droop to the tip. Although=
many fit into a comfortable range of medium-length,straight, stout bills, =
others show a much longer, thinner bill, with a small number having very sh=
ort bills with tapered tips that more resemble Semipalmated Sandpipers . I =
have not personally seen any studies where bill length and shape have been=
=C2=A0attributed to geographic populations, but I would be surprised if the=
re were any distinct ranges without overlap by the other regional populatio=
ns. I do acknowledge that several birds in Norman''s photos show very short=
bills, and the percentage of these short-billed birds in his photos is muc=
h greater than you would find in North American flocks. However, there are =
some very long billed birds in his photos as well. Since he sees more of th=
e Eurasian nesting birds, I would guess that short billed birds are fairly =
common in this population group, and possibly representative, but there are=
a small number of birds in North America that also have very short bills.=
=20
I have provided a link to a number of breeding Sanderling photos that I too=
k in NJ and Florida in May: http://www.kevinkarlsonphotography.com/gallery/=
v/Shorebirds/Sandpipers/Turnstones/=20
=C2=A0 Two photos (one perched; one flight) show birds with a mix of rusty =
and silver feathers, and also a mix of breeding and nonbreeding wing covert=
s. These might be first calendar year birds, or birds that did not have suf=
ficient energy or hormonal levels to achive full replacement of breeding fe=
athers. I see this condition on many Short-billed Dowitchers that stage nea=
r my house in spring, with some replacing virtually all wing coverts with b=
reeding feathers, and others a=C2=A0mixture of breeding feathers from 20 - =
80 percent. I don't believe that age is the sole determinant for the amount=
of breeding feathers replaced, but a combination of factors is responsible=
for this condition. I also posted a few new photos showing variation of pl=
umage in a small flock and large flock of Sanderlings photographed on May 2=
7, 2005 . The birds in the small flock all show a number of nonbreeding win=
g coverts, which might reflect young birds or ones that have low energy lev=
els for feather replacement. However, both photos show typical variation in=
plumage of Sanderling flocks at various times during mid-May to early June=
. The larger flock with Red Knots shows a great deal of variation in plumge=
, from very rusty males to very pale birds.=20
As for Al's comment on West Coast breeding Sanderlings showing white feathe=
ring within the rust coloration and whether Atlantic Coast birds also show =
this trait, I would say that some do=C2=A0while others =C2=A0have complete =
rust and black coloration with minimal white or gray feathering intersperse=
d throughout the head, upperparts and throat. A few of the breeding birds o=
n my website show birds from both Florida and NJ in May that do not show an=
y noticeable white or gray feathering to these areas. In conclusion, I see =
no difference in the plumage condition of=C2=A0Norman's Sanderling photos=
=C2=A0and the many images I have of North American Sanderlings from the Atl=
antic Coast, even in deep rusty males.=20
I also posted these photos in response to Norman's request for Sanderling i=
mages. I have about a thousand more images in raw format and slides, but ne=
ed to go back to work.=20
Kevin Karlson=20
----- Original Message -----=20
From: "Norman D.van Swelm" <Norman.vanswelm(AT)WXS.NL>=20
To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU=20
Sent: Thursday, June 25, 2009 7:56:20 AM GMT -05:00 US/Canada Eastern=20
Subject: [BIRDWG01] Do Canadian Sanderlings Calidris a. rubidus migrate to =
and from Europe as well?=20
Have a look here please:=20
=C2=A0=C2=A0http://www.radioactiverobins.com/snipes-waders/sanderlings%20in=
%20a%20storm.htm=20
and share your opinion with all of us.=20
Cheers, Norman=20
Join or Leave BIRDWG01: http://listserv.arizona.edu/cgi-bin/wa?SUBED1=3Dbir=
dwg01=20
Archives: http://listserv.arizona.edu/archives/birdwg01.html=20
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[ << | >> | ^^ ]
Subject: Re: Do Canadian Sanderlings Calidris a. rubidus
migrate to and from Europe as well?
From: "Norman D.van Swelm" <Norman.vanswelm(AT)wxs.nl>
Date: 26 Jun 2009 5:02am
This is a multi-part message in MIME format.
----INCLUDING text/plain MIME SECTION----
Thank you Kevin for your very interesting reply and great photo's, I =
would love to see more!
Rusty males as shown in 4th picture on our website are a minority in the =
flocks we see and I dare say males can also look pretty grey as can be =
seen in 6th picture showing a male (left) and a female.
I wonder if the presence of short-billed birds among the birds you see =
can be explained by the presence of birds from Greenland and/or =
Ellesmere?
The fact you see no difference in the plumage condition of my Sanderling =
photos and the many images you have of North American Sanderlings from =
the Atlantic Coast, even in deep rusty males may indicate that all are =
of Canadian stock. From what I have seen so far it looks as if birds =
from Greenland are a bit duller in colour. I'll consult Jeroen =
Reneerkens on this. In an earlier discussion he mentioned that =
Sanderlings from Greenland are in Scotland in the beginning of May and a =
little later in Iceland. Same as with Red Knots from Greenland which =
have left the North Sea by the end of April to fatten in Scotland and =
North Norway hence we never see them in fresh breeding plumage.
Cheers, Norman
Kevin Karlson wrote: >I read Norman's points with interest, but would =
like to address a few points.
I have been studying Sanderlings on the Atlantic Coast near my house on =
Reeds Beach Road near the Delaware Bay for many years. I get to see many =
thousands of Sanderlings each year as they fatten up on Horseshoe Crab =
eggs prior to departing for their Arctic breeding areas. Many don't =
leave until early June, and attain full breeding plumage by then. The =
incredible variety in plumage color, shading and intensity is hard to =
believe, and I often wondered why only a percentage of these birds =
showed the 'classic' deep rust and black breeding plumage depicted in =
most popular North American field guides as "breeding plumage". I =
eventually realized that these guides were incorrect in only depicting a =
rusty plumage condition as breeding plumage, and should have showed a =
variety of rust, silver and black plumage states for breeding plumage.=20
When we published the Shorebird Guide, we showed a photo of three adult =
Sanderlings in breeding plumage, with only one having deep rust plumage =
color, and the other two showing a mix of silver and black upperpart =
feathers with a smattering of rust internal markings. It is now obvious =
that some birds are deep rust in breeding plumage; others are somewhat =
rusty, with a mix of silver feathers; and others are mostly silver and =
black. These are adult birds that I am speaking of, with some first =
calendar year birds typically showing reduced rust color and variable =
amounts of retained juvenile wing coverts and flight feathers, or a mix =
of breeding, nonbreeding and juvenile feathers. My point is that there =
is really no way to say that these birds ever show a characteristic =
breeding plumage condition with respect to depth of rust and black =
versus silver and black color, and I doubt that there is a reliable way =
to separate them from other regional populations. The degree of =
variation in North American Sanderlings with respect to breeding plumage =
color is extraordinary, and overlooked by most birders.=20
As for bill size being a determining factor for different geographical =
breeding populations, I would think that would be hard to conclusively =
apply as well. I see a great deal of variation with length and shape of =
Sanderling bills in NJ and Florida each year. Some are short and stubby, =
while others are noticeably longer and thinner, with a slight droop to =
the tip. Although many fit into a comfortable range of =
medium-length,straight, stout bills, others show a much longer, thinner =
bill, with a small number having very short bills with tapered tips that =
more resemble Semipalmated Sandpipers. I have not personally seen any =
studies where bill length and shape have been attributed to geographic =
populations, but I would be surprised if there were any distinct ranges =
without overlap by the other regional populations. I do acknowledge that =
several birds in Norman''s photos show very short bills, and the =
percentage of these short-billed birds in his photos is much greater =
than you would find in North American flocks. However, there are some =
very long billed birds in his photos as well. Since he sees more of the =
Eurasian nesting birds, I would guess that short billed birds are fairly =
common in this population group, and possibly representative, but there =
are a small number of birds in North America that also have very short =
bills.
I have provided a link to a number of breeding Sanderling photos that I =
took in NJ and Florida in May: =
http://www.kevinkarlsonphotography.com/gallery/v/Shorebirds/Sandpipers/Tu=
rnstones/
Two photos (one perched; one flight) show birds with a mix of rusty and =
silver feathers, and also a mix of breeding and nonbreeding wing =
coverts. These might be first calendar year birds, or birds that did not =
have sufficient energy or hormonal levels to achieve full replacement of =
breeding feathers. I see this condition on many Short-billed Dowitchers =
that stage near my house in spring, with some replacing virtually all =
wing coverts with breeding feathers, and others a mixture of breeding =
feathers from 20 - 80 percent. I don't believe that age is the sole =
determinant for the amount of breeding feathers replaced, but a =
combination of factors is responsible for this condition. I also posted =
a few new photos showing variation of plumage in a small flock and large =
flock of Sanderlings photographed on May 27, 2005. The birds in the =
small flock all show a number of nonbreeding wing coverts, which might =
reflect young birds or ones that have low energy levels for feather =
replacement. However, both photos show typical variation in plumage of =
Sanderling flocks at various times during mid-May to early June. The =
larger flock with Red Knots shows a great deal of variation in plumage, =
from very rusty males to very pale birds.
As for Al's comment on West Coast breeding Sanderlings showing white =
feathering within the rust coloration and whether Atlantic Coast birds =
also show this trait, I would say that some do while others have =
complete rust and black coloration with minimal white or gray feathering =
interspersed throughout the head, upperparts and throat. A few of the =
breeding birds on my website show birds from both Florida and NJ in May =
that do not show any noticeable white or gray feathering to these areas. =
In conclusion, I see no difference in the plumage condition of Norman's =
Sanderling photos and the many images I have of North American =
Sanderlings from the Atlantic Coast, even in deep rusty males.
I also posted these photos in response to Norman's request for =
Sanderling images. I have about a thousand more images in raw format and =
slides, but need to go back to work.=20
Kevin Karlson
From: "Norman D.van Swelm" <Norman.vanswelm(AT)WXS.NL>
To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
Sent: Thursday, June 25, 2009 7:56:20 AM GMT -05:00 US/Canada Eastern
Subject: [BIRDWG01] Do Canadian Sanderlings Calidris a. rubidus migrate =
to and from Europe as well?
Have a look here please:
=
http://www.radioactiverobins.com/snipes-waders/sanderlings%20in%20a%20sto=
rm.htm
Join or Leave BIRDWG01:
http://listserv.arizona.edu/cgi-bin/wa?SUBED1=3Dbirdwg01
Archives: http://listserv.arizona.edu/archives/birdwg01.html
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Subject: Re: Unidentified Catharus thrush
From: Peter Pyle <ppyle(AT)BIRDPOP.ORG>
Date: 26 Jun 2009 10:56am
----INCLUDING text/plain MIME SECTION----
Thanks for the many responses we got on this thrush identification,
primarily off-list. The consensus is that this was a Swainson's
Thrush of one of the populations other than the "Russet-backed"
(usutulatus) Group of the Pacific Coast. There were a few opinions
for Gray-cheeked or Hermit Thrush but the washed out imagery seems to
be responsible for this bird's resembling these species.
There were more varied opinions regarding which population of
Swainson's Thrush this bird may have originated from. The taxonomy of
this species is interesting, with Great Basin populations aligned
with Eastern ("Olive-backed") populations rather than forming their
own group, as occurs with several other polytypic North American
species. These populations, which breed as close to us as California
east of the Sierra Nevada, have even been considered the same
subspecies (swainsoni) that breeds in boreal northeastern forests
(AOU 1957, Phillips 1991, etc.), and genetic studies performed by
UCLA supports this opinion
(http://rspb.royalsocietypublishing.org/content/269/1498/1375.full.pdf+html).
Certain interior western populations have been considered a separate
subspecies by some ("almae"), slightly grayer-backed as to be
expected, but this differences seems to be slight at best. Another
subspecies of the eastern Olive-backed Group, incanus (wrongly placed
in the ustulatus group in the Identification Guide), breeds in Alaska
and also averages grayer than typical swainsoni.
Opinion on the Bolinas bird varied from swainsoni from the east to
swainsoni from the west ("almae") to incanus, but given the images
and the morphological similarity of these taxa, I don't think we can
safely assume anything about this. A western origin for the bird
might be expected based on range, but vagrants of other
western-breeding Catharus (Veery, Gray-cheeked Thrush) are extremely
rare in California, and could equally well have come from eastern
populations. Indeed, this is only the 4th or 5th non-ustulatus
Swainson's Thrush I know of from central coastal California; I only
observed two on the Farallon Islands during a 24-year span there.
Peter Pyle
At 11:58 AM 6/25/2009, Peter Pyle wrote:
>Hello again-
>
>Keith Hansen videotaped a Catharus thrush in Bolinas, central
>coastal California, on 15 June 2009 that we'd like to get some
>opinion on. There is general agreement that it is not of our locally
>breeding Swainson's Thrush but there are some divergent opinions
>beyond this. The video and some still grabs from it can be found here:
>
>http://keithhansen.wordpress.com/
>
>Many thanks,
>
>Peter Pyle
>
>Join or Leave BIRDWG01:
>http://listserv.arizona.edu/cgi-bin/wa?SUBED1=birdwg01
>
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