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ID-FRONTIERS for November 26-30, 2000
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Subject: Re: Archives?
From: Don Crockett <crockett(AT)GREATBLUE.COM>
Date: 26 Nov 2000 4:15pm
You can get access to all the messages since Jan. 1, 2000
for ID-Frontiers at:
http://www.virtualbirder.com/bmail/idfrontiers/latest.html
Click on the 'Month' link to get to previous months.
Unfortunately it's not particularly user friendly, no search
capability, just messages organized by date.
Don
>How does one (or can one) access BIRDWG01 archives beyond what is available
>on Birding on the Web?
>Any tips much appreciated.
>Ross
>
>Ross Silcock
>Tabor, IA
>silcock(AT)sidney.heartland.net
>http://sidney.heartland.net/silcock
Don Crockett
The Virtual Birder(R)
http://www.virtualbirder.com
A 2 Z 4 Birders(sm): The Store
http://store.yahoo.com/a2z4birders
mailto:crockett(AT)greatblue.com
Brookline, Massachusetts
[ << | >> | ^^ ]
Subject: Re: Mew Gull, the odd one out
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 27 Nov 2000 11:39am
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----
I have spent quite a bit of time looking at the wing-tip pattern of Mew
Gulls in California the last couple of winters. Of course, as Norm
discovered, it is impossible to be sure of the precise details of the
wing-tip patterns without photographs. However, I did see great variation
with some birds showing very obvious white on P8 to other birds that seemed
to show little/none.
If this is the same bird that Norm posted some months ago, I felt as typical
Mew (using Mew as the name for the American form) Gull could be eliminated
by the pattern of the head/neck streaking.
-----Original Message-----
From: norman van swelm [mailto:Norman.vanswelm(AT)WXS.NL]
Sent: Friday, November 24, 2000 5:03 PM
To: BIRDWG01(AT)LISTSERV.ARIZONA.EDU
Subject: [BIRDWG01] Mew Gull, the odd one out
As you may remember, last winter Peter de Knijff and I found a gull, here in
The Netherlands, showing characters of Short-billed Gull L.c.brachyrhynchus.
It stayed two months during which we took many photo's, some of which are on
show on Martin Reids gull page. We did all we could to see and photograph
the narrow white wedge separating the black tip from the grey base of
primary 8. This is important since it is considered diagnostic in
distinguishing brachyrhynchus from all other races of Larus canus. No matter
what we did we could not get a good or long enough view of the 8th primary
of this bird. It was so confident that it either sat for hours at a few
metres from us without blinking an eye and when it moved, in order to chase
a Black-headed Gull away, it did so too unexpectedly to see anything. The
pleasant thing was that it considered us as something worth fighting for! On
the
pictures however there seems to be no or hardly any white wedge, hence it
being disqualified as brachyrhynchus! During our further studies and with
the help of Pim Wolf, who incidentally saw the bird as well, we established
that our Dutch breeding bird, which because of its small size I choose to
name L.canus minor, can show a white wedge in P8 as well! Indeed we found
out that
the same also holds true in L.c.kamtchatchensis! So, if someone sees a
L.canus with a white wedge on P8 in Europe or Japan, that someone cannot be
certain it is a brachyrhynchos despite it being considered as diagnostic!
But what about the other way around? Are there any L.c.brachyrhynchus in
America or Canada without a white wedge in P8?
Ron Pittaway brought us in contact with Michel Gosselin (Collection
Services, Canadian Museum of Nature, P.O. Box 3443, Station D Ottawa,
Ontario CANADA K1P 6P4) and he has had a bit of research done for us. He
reports the following:
'I had someone go over the 60 or so adult Mew Gulls in the collection to
see if any were missing a white wedge on P8, and she found one (only) such
specimen: CMNAV 49769, a female taken at Tuya Lake, B.C.,16 July 1962. It
has only a thin (c. 1 mm) light line between the black and the gray areas of
the wing. Our one specimen of kamtschatschensis (from Japan) also has no
white wedge.'
Now, does one bird challenges the diagnosibility of brachyrhynchus versus
the other canus races when found in the US or Canada? Perhaps not (yet) but
from personal experience I can assure you that it would take magical eyes to
see a 1 mm light line on P8 in a wild bird! So is it not time to look for
easier clues? Some of my earlier findings have been mentioned before in
Martin Reid's postings (head, bill, tail, undertail coverts, short tarsi).
Perhaps the old name Short-billed Gull is not so bad after all, mewing
doesn't seem so diagnostic for a gull?
So may I invite you all to have a look at brachyrhynchus' P8 this winter and
send your results to ID Frontiers?
Norman D.van Swelm
----DELETED text/html MIME SECTION----
[ << | >> | ^^ ]
Subject: Golden Plovers
From: DJLauten and KACastelein <birdsong(AT)HARBORSIDE.COM>
Date: 27 Nov 2000 1:00pm
> Hello. Back to my currently favorite birds.
>
> <Tundra Plovers>, page Table 4, page 402, in listing field marks for
> "fully developed breeding plumages (males), for American Golden
> ..dominica.. and Pacific Golden ..fulva.., states that "Vent & under
> tail coverts" for American are "black" and for Pacific are "Black,
> varying amount of white". From this it appears that a white vent and/or
> undertail coverts is diagnostic for adult breeding Pacific, while black
> does not distinguish between the two species. Do you agree?
Jim,
In my experience on the Oregon coast, I would agree with the above as long
as one is confident that the birds have completed prealternate molt.
>
> And now the real question: What holds for "Vent & under tail
> coverts" for transitional birds in August, September, October, and for
> birds in full basic plumage? Do white undertail coverts, for example,
> eliminate American?
No, for both questions. The problem is we see adults of both species in
varying stages of molt on their return. It is not clear to me whether the
undertail coverts molt at the same time as other body feathers or later or
earlier. My guess is that it is a bit variable between individuals.
Therefore a partially molted adult with white undertail feathers is not
necessarily a Pacific and American cannot be ruled out.
Dave Lauten
>
> Thanks for your help.
>
> Jim Barton
> redwing1986(AT)mediaone.net
> Cambridge, MA
Dave Lauten and Kathy Castelein
Bandon, OR
birdsong(AT)harborside.com
[ << | >> | ^^ ]
Subject: Eastern/Spotted Towhee hybrids?
From: "David R." <david(AT)BIRD-BRAIN.COM>
Date: 30 Nov 2000 8:16pm
A couple of weeks ago, I saw a towhee in Southwest Missouri that I at first
believed to be a male Spotted Towhee. That species does occur in the state,
though it is by no means common.
I was quite close to the bird and had 10x50 binoculars, so I would say I had
pretty good looks at it.
The only reason I am confused is that as best I recall, the bird only had white
spotting on its wing coverts, not its back. It could be that with its dark
black feathers I couldn't distinguish where the coverts stopped and the back
began. But it definitely did _not_ have any spotting in the middle of the back.
(I realize that the amount of white varies with the subspecies.) I didn't
know at the time to look for white on the back, and I didn't have a good field
guide with me. The bird was never relocated.
How could I be sure I didn't see a Eastern x Spotted hybrid? If I am sounding
pretty ignorant, I guess its because I am.
I know there are some great birders on this listserv, and I would really, really
appreciate help in clenching this species for my Missouri and life lists.
Thanks.
David
david(AT)bird-brain.com
"But God demonstrates His own love for us in this: while we were still sinners
Christ died for us." Romans 5:8
----------------------------------------------------------------------
Free, secure email for bird lovers:
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[ << | >> | ^^ ]
Subject: Re: shearwater id
From: Don Crockett <crockett(AT)GREATBLUE.COM>
Date: 30 Nov 2000 10:00pm
I finally got a chance to compile the comments I received
about identifying the wingtip-to-wingtip dark shearwaters
from web images of a slide I shot on Cordell Banks in
November 1998. You can find the images and all of the
comments I received at:
http://www.virtualbirder.com/ncal/shearwaterid.html
There wasn't much controversy about the ID of either of the
birds (other than the fact that I dyslexically mis-labeled
the images in my original post).
The left bird was IDed by almost everyone as a Short-tailed
Shearwater based on shorter, thin bill, steep rounded forehead,
smaller head, whitish chin, fairly uniform silvery underwing.
Right bird is a Sooty Shearwater based on larger head and
shoulders, flatter forehead, larger/chunkier bird,
thicker and longer bill, darker chin, more contrast in
secondary underwing pattern.
I did end up using the image in the Birding Break for
Northern California. People interested in a simulated
birding trip should check out:
http://www.virtualbirder.com/ncal/index.html
Thanks for everyone's feedback. I'll add any other comments
I receive to the web page.
Don
Don Crockett
The Virtual Birder(R)
http://www.virtualbirder.com
A 2 Z 4 Birders(sm): The Store
http://store.yahoo.com/a2z4birders
mailto:crockett(AT)greatblue.com
Brookline, Massachusetts
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