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ID-FRONTIERS for October 1-5, 2002
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Messages are displayed in the order they were received.
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| Subject | From | Date | Time |
| Re: Lark photo | Lethaby, Nick | Tue, 1 Oct 2002 | 7:57am |
| Re: White-headed Woodpecker in Montana? | Caleb Putnam | Wed, 2 Oct 2002 | 8:08am |
| I: [EuroTwitch] Western Crowned Leaf Warbler in
Norway? | Menotti Passarella | Thu, 3 Oct 2002 | 9:32am |
| Western Crowned Leaf Warbler In Norway | EDDIE CHAPMAN | Thu, 3 Oct 2002 | 11:53am |
| Re: Western Crowned Leaf Warbler In Norway | Lethaby, Nick | Thu, 3 Oct 2002 | 12:16pm |
| QRY: Occurence of melanistic Broad-wing H (NOT
dark morphs) | Jim Barton | Thu, 3 Oct 2002 | 12:56pm |
| ''crowned' warbler in Norway | Brian Small | Thu, 3 Oct 2002 | 1:31pm |
| Re: ''crowned' warbler in Norway | Lethaby, Nick | Thu, 3 Oct 2002 | 1:49pm |
| White-winged Tern ageing / RFI | Ned Brinkley | Sat, 5 Oct 2002 | 9:22am |
| Re: White-winged Tern ageing / RFI | Colin Bradshaw | Sat, 5 Oct 2002 | 10:09am |
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To use email addresses replace '(AT)' with '@'.
This is done to confuse the spam 'bots.
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[ << | >> | ^^ ]
Subject: Re: Lark photo
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 1 Oct 2002 7:57am
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this format, some or all of this message may not be legible.
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This looks like a fairly obvious Horned Lark so I would agree with Mike
Patterson on this.
-----Original Message-----
From: Ian Paulsen [mailto:ipaulsen(AT)KRL.ORG]
Sent: Monday, September 30, 2002 10:38 PM
To: BIRDWG01(AT)listserv.arizona.edu
Subject: [BIRDWG01] Lark photo
HI ALL:
Any comments??
Ian Paulsen
Bainbridge Island, WA, USA
ipaulsen(AT)krl.org
A.K.A.: "Birdbooker"
"Rallidae all the way"
---------- Forwarded message ----------
Date: Mon, 30 Sep 2002 21:22:05 -0700
From: Mike Patterson <celata(AT)pacifier.com>
To: Greg Gillson <greg(AT)thebirdguide.com>, tweeters
<tweeters(AT)u.washington.edu>
Cc: Obol <obol(AT)lists.orst.edu>
Subject: Re: Photo ID help
If you blow up the first picture and look at the claw on
the hind toe...
I think this is a hatch-year Horned Lark.
It is not any kind of bunting, I suppose it could be some
sort of weird asian lark (I don't have a good asian field guide)
Greg Gillson wrote:
>
> Troy Guy was at sea off Washington State when this bird he couldn't
identify
> flew aboard. My wild guess is some kind of Asian bunting. Anyone else want
> to venture a guess and notify the Washington Records Committee (perhaps by
> means of forwarding this message to Tweeters for me?) Thanks.
>
> http://thebirdguide.com/temp_images/Dscn1924.jpg
> http://thebirdguide.com/temp_images/Dscn1922.jpg
> http://thebirdguide.com/temp_images/Dscn1923.jpg
>
> Greg Gillson
> Cornelius, Oregon
> greg(AT)thebirdguide.com
> http://thebirdguide.com
--
Mike Patterson
Astoria, OR
celata(AT)pacifier.com
A child who becomes acquainted with the birds about him
hears every sound and puzzles out its meaning with a cleverness
that amazes those with ears who hear not.
-Neltje Blanchan
http://www.pacifier.com/~mpatters/bird/bird.html
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Subject: Re: White-headed Woodpecker in Montana?
From: Caleb Putnam <larus10(AT)HOTMAIL.COM>
Date: 2 Oct 2002 8:08am
Mike and ID-Frontiers-
I read with interest your report of possible White-Headed Woodpeckers (WHWO)
in Montana. The species has not been recorded breeding in Montana.
However, it occurs as a rare fall and winter transient, mainly in the NW
corner of the state.
Sibley's green dot in the Beartooth area does not represent any known record
of the species. The species has never been recorded in the Beartooth
Plateau, and seems unlikely to occur there (in any season) for a couple of
reasons.
First, almost all recent records of this species are from the Northwest
corner of the state (Lincoln and Flathead Counties). The Beartooth Highway
is in the south central part of the state, with the nearest record of WHWO
coming from Gallatin County (>100 miles away), and this record is listed
only as hypothetical by Saunders, 1921, p174.
Secondly, all Montana records of the species have occurred in low-elevation
Ponderosa Pine forest, usually below ~5000 ft. The Beartooth Highway is
approx. 7,000 ft - 10,000 ft in elevation and probably consists mainly of
subalpine fir, logdepole pine, and whitebark pine. The occurrence of this
species in this habitat (in MT) would be unprecedented, albeit not
impossible.
I'd be very interested in how you made your identifications. Please submit
a rare bird report to the Montana Bird Records Committee (I’d be happy to
mail you the form and instructions if you need it), assuming the sightings
occurred on our side of the border.
Cheers,
Caleb Putnam
Stevensville, MT, USA
larus10(AT)hotmail.com
References Cites
Saunders, A.A. 1921. A distributional list of the birds of Montana.
Pacific Coast Avifauna Nr 14. 194p.
>In mid August I drove the Beartooth Hwy (which straddles the border of
>Montana and Wyoming) and twice I had birds fly overhead that appeared >to
>be White-headed Woodpeckers. I've always thought of them as being >
>restricted to the far west, and when I checked my NG 3rd ed. and saw >the
>range extend only into central Idaho, I started to wonder what I >may have
>seen- White-headed Woodpeckers, after all, are pretty >distinctive.
>However, when I got back home I checked Sibley, and sure >enough, there is
>a dot right on the border in the area of the >Beartooth. To those
>of you who are familiar
>with that area- Is this a well known disjunct population? Does anyone
> >know if the new NG guide will reflect this population?
>I must admit that while I liked the Sibley guide when it came out, I >was
>not 'knocked out' by it as many other folks seemed to be. Now >that it
>has apparently saved me a life bird I think I like it a little >more!
>Mike Cooper
>Ridge, LI, NY
_________________________________________________________________
Join the world’s largest e-mail service with MSN Hotmail.
http://www.hotmail.com
[ << | >> | ^^ ]
Subject: I: [EuroTwitch] Western Crowned Leaf Warbler in
Norway?
From: Menotti Passarella <menotti.passarella(AT)LIBERO.IT>
Date: 3 Oct 2002 9:32am
----- Original Message -----
>From: Vegard Bunes <dumetorum(AT)yahoo.com>
>To: <birdline(AT)yahoogroups.com>
>Sent: Thursday, October 03, 2002 6:04 PM
>Subject: [EuroTwitch] Western Crowned Leaf Warbler in Norway?
>Hi all,
>An unusual Phylloscopus Warbler was trapped and ringed in South Western
>Norway on Sept 30th. Could it be a Western Crowned Leaf Warbler
>(Phylloscopus occipitalis), a new to the Western Palearctic?
>See images at:
>http://www.feltornitologene.no/artikler/phylloscopuseng.htm
°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
Hi all.
What about Phylloscopus coronatus (Eastern Crowned Warbler) ?
See images of it at:
http://makeashorterlink.com/?A2B412EF1
According to me, this latter is very similar to the Norwegian bird...
Cheers
Menotti Passarella
Italy
[ << | >> | ^^ ]
Subject: Western Crowned Leaf Warbler In Norway
From: EDDIE CHAPMAN <echapman(AT)ONLINE.NO>
Date: 3 Oct 2002 11:53am
Menotti Passarella mentioned Eastern Crowned Warbler Phylloscopus
coronatus. If my memory serves me correctly, this species has been seen in
Europe once before. Anyone got any details about that observation.
All the best,
Eddie Chapman. Voss. Norway.
Bird Watching In Norway: http://www22.brinkster.com/birdwatch/index.htm
Guide Service - Birding Holidays - Norwegian Rare Bird Alert
[ << | >> | ^^ ]
Subject: Re: Western Crowned Leaf Warbler In Norway
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 3 Oct 2002 12:16pm
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this format, some or all of this message may not be legible.
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Eastern Crowned Warbler I believe was seen/trapped on Heligoland many
decades ago.
I don't see anything wrong with this bird for Eastern Crowned. I've seen
plenty of these, but unfortunately never seen a Western Crowned so don't
know what that looks like.
-----Original Message-----
From: EDDIE CHAPMAN [mailto:echapman(AT)ONLINE.NO]
Sent: Thursday, October 03, 2002 11:48 AM
To: BIRDWG01(AT)listserv.arizona.edu
Subject: [BIRDWG01] Western Crowned Leaf Warbler In Norway
Menotti Passarella mentioned Eastern Crowned Warbler Phylloscopus
coronatus. If my memory serves me correctly, this species has been seen in
Europe once before. Anyone got any details about that observation.
All the best,
Eddie Chapman. Voss. Norway.
Bird Watching In Norway: http://www22.brinkster.com/birdwatch/index.htm
Guide Service - Birding Holidays - Norwegian Rare Bird Alert
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Subject: QRY: Occurence of melanistic Broad-wing H (NOT
dark morphs)
From: Jim Barton <redwing1986(AT)ATTBI.COM>
Date: 3 Oct 2002 12:56pm
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Friends, in the course of my research on Dark Morph Broad-winged =
Hawks, I've encountered a photo of what appears to be a truly melanistic =
individual---an adult (as indicated by the central white tail band) =
which is near totally dark brown below. Oddly, the cheek, throat and =
patagial are are a shade lighting than the body and underwing coverts. =
Except for that, the bird shows no contrast on the underwing, as one =
would expect on a true dark morph. In particular, the inner shafts of =
the outer primaries are as dark as the outer shafts. =20
l'm hoping the observer will be willing to make his photos available =
for discussion, and I'm recommending to him that we wait to post them =
until the end of this month, when hawkwatchers will have time and =
inclination to look a computer monitors rather than live birds. =20
Meantime, I'm wondering whether any one else has photographed or =
reported an almost totally dark brown BWHA. =20
Yours,=20
Jim Barton
redwing1986(AT)attbi.com
Cambridge, MA
US Coordinator Proact in the Americas
Campaigning for birds and their habitats before it's too late
www.proactnow.org
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Subject: ''crowned' warbler in Norway
From: Brian Small <BrianJSmall(AT)AOL.COM>
Date: 3 Oct 2002 1:31pm
All
Ther have been some suggestions of Eastern Crowned by from my experience
these have obvious yellow on the indertail coverts. Try to find any good
descriptions or illustrations side-by-side of occipitalis and coronatus and
you might struggle. Ali and Ripley (Birds of India and Pakistan) treat the
two as races, but give the white underparts and bright yellow undertail
coverts of coronatus (E Crowned) as the key features between the two -
otherwise they are quite similar.
As I said, I cannot see yellow on the undertail coverts so obvious on birds I
have seen in China, so this would support it as Western Crowned as the site
suggests.
Brian Small
[ << | >> | ^^ ]
Subject: Re: ''crowned' warbler in Norway
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 3 Oct 2002 1:49pm
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this format, some or all of this message may not be legible.
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Given the angle of the photos don't show the vent really clearly, I'm not
sure it's possible to say this bird does not have any yellow. Also, I
wouldn't agree that the yellow is always obvious - often it's quite subtle
in my experience, although it's always there if you get a good enough view
in the right light.
-----Original Message-----
From: Brian Small [mailto:BrianJSmall(AT)AOL.COM]
Sent: Thursday, October 03, 2002 1:32 PM
To: BIRDWG01(AT)listserv.arizona.edu
Subject: [BIRDWG01] ''crowned' warbler in Norway
All
Ther have been some suggestions of Eastern Crowned by from my experience
these have obvious yellow on the indertail coverts. Try to find any good
descriptions or illustrations side-by-side of occipitalis and coronatus and
you might struggle. Ali and Ripley (Birds of India and Pakistan) treat the
two as races, but give the white underparts and bright yellow undertail
coverts of coronatus (E Crowned) as the key features between the two -
otherwise they are quite similar.
As I said, I cannot see yellow on the undertail coverts so obvious on birds
I
have seen in China, so this would support it as Western Crowned as the site
suggests.
Brian Small
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Subject: White-winged Tern ageing / RFI
From: Ned Brinkley <Phoebetria(AT)AOL.COM>
Date: 5 Oct 2002 9:22am
The recent visit of a White-winged Tern to Chincoteague National Wildlife
Refuge, Accomack County, Virginia, 6-9 September 2002 should probably get a
little more discussion than it has had on the Internet, inasmuch as the bird
was neither in juvenal plumage nor, possibly, in typical adult basic plumage,
and too because the species is rarely seen in North America in recent years.
My attempts to get to the bottom of how to age this White-winged Tern have
not ended, and I welcome thoughts on the subject from experienced observers
here. I should acknowledge the help of Jonathan Alderfer, who has provided a
great deal of background material and obscure literature in the past weeks.
I do have access to much relevant literature, but I do not have access to the
following articles, all of which probably have some important clues or
photographs of relevant plumages (apologies for the absence of diacritical
marks and italics):
Doherty, P. 1989. Ageing of White-winged Tern. Birding World 2: 328-329.
Olsen, K. M. 1989. Art- och alderbestamning av Chlidonias-tarnor
[Identification and ageing of Chlidonias terns]. Parts 1 and 2. Calidris
18: 11-20 & 165-170.
Breife, B. 1991. Svarttarna och vitvingad tarna i vinterdrakt [Black Tern
and White-winged Tern in winter plumage]. Calidris 20: 90.
van IJzendoorn, E. J. and J. D. de Miranda. 1980. Over verenkleden van
Witvleugelstern in september [On plumages of White-winged Tern in September].
Dutch Birding 2: 62-64.
van IJzendoorn, E. J. and J. D. de Miranda. 1980. Onvolledig zomerkleed
bij Witvleugelstern [Incomplete alternate plumage in White-winged Tern].
Dutch Birding 1: 108.
If anyone has easy access to these articles and is willing to photocopy and
mail them, I'll gladly reimburse the effort in whatever way seems best [the
address here is 9 Randolph Avenue, Cape Charles, Virginia, USA 23310]. I
assume that the Olsen article's contents are incorporated, for the most part,
in his book with Hans Larsson (Terns of Europe and North America; see below).
+++++++
Background
I found the bird in company with 6 or 7 Black Terns at Swan Cove on the
refuge, in the afternoon of 6 September 2002. I first observed the bird at
about 1415 EDST, then not again until 1530. Total observation time was about
20-25 minutes at distances of 40-200 m with a Swarovski scope fitted with 30x
wide eyepiece. Light was excellent at all times. Comparisons with Black
Tern were relatively easy, though the bird did not appear especially to
associate with or forage in concert with Black Terns. As were the Black
Terns, the White-winged was in flight and apparently foraging during all
observations. Like the Blacks, it flew along the edgse of Swan Cove, mostly
the western and northern sides, about 4-10 m above the water as it watched
the water's surface, occasionally dipping (not diving) to the surface in
apparent attempts to seize prey. The bird's behavior while present did lend
permit photography. The bird did not call during the observation at close
range.
The bird was also seen by Tom Pendleton and Ben Copeland during the second
observation; later in the day, Fenton Day, Bev Leeuwenburg, Larry Lynch, Bill
Akers, and many others saw it (a state ornithological meeting commenced there
that afternoon). On the next day, an observer from New Jersey saw it, also
in the afternoon. On the 8th, Mike and Dixie Overton, Todd Day, Sue Heath,
Jon Little, and Grayson Pearce observed the bird. On the 9th, I looked for
the bird in the afternoon unsuccessfully, but earlier, at 1300, Michael
Retter and Nick Block found the bird, again in Swan Cove. That was the final
observation of the bird; a cold front apparently ushered it and the Black
Terns off to parts unknown on the following day. Though a few Black Terns
can linger in this region until the first days of October (as one juvenile
did in 2000), most coastal birds depart by mid-September, about the same time
the last Least Terns depart.
In direct comparison with Black Terns (both juveniles and adults), the
White-winged showed a different overall shape, bill proportions, appearance,
and flight behavior.
1) The bird's black bill was obviously, noticeably slight in comparison to
those of the Black Terns, certainly shorter than those of nearby Black Terns.
It was really astonishing to me how visible the difference was at distances
even over 100 m.
2) The proportions and shape of the White-winged Tern were also consistently,
rather strikingly different from the Black Terns'. The birds' wings were
less sharply pointed at the tip, and perhaps (proportionately) slightly wider
than those of the Black Terns. The tail was not noticeably forked but
appeared rather square-ended at most distances; a very slight difference
between outer and inner rectrix length was barely perceivable at closest
range, but this never produced the impression of a "forked" tail.
3) Flight style of the bird was rather like the Black Terns', but the bird's
wingstrokes were a bit shallower, its moves less darting, swooping, and
nimble on the whole, appearing more "methodical" and less swallowlike.
4) The body of the bird appeared more robust than those of the apparently
slenderer Black Terns; overall, the bird appeared a bit "stumpier" than the
Blacks and smaller by a bit.
The bird's rather starkly white head showed clear, small dark patches of
black at the ear coverts, joined tentatively by a little grayish stippling
over the mid-crown that narrowed and tapered off at the central upper
hindcrown. The nape/collar was starkly white, like the rest of the head.
The overall impression of the white-looking head (and indeed the overall
impression of the bird), with its small bill and almost doll-like,
round-headed jizz, was that of a Little Gull in basic plumage, with its large
dark eye surrounded entirely by white (no dark in the lores) and the
impression, at most distances, of simply dark ear covert spots. This in an
oft-cited comparison in the identification literature on this species and is
surprisingly apt.
Dorsal and ventral plumage.
Just to serve as points of reference, I'll mention two texts familiar to
subscribers on this service: the Sibley Guide to birds of North America, and
the Mullarney/Svensson/Zetterstrom/Grant Birds of Europe. Tom Pendleton and
I made reference to these while watching the bird in the field and making
notes, and the closest plumages illustrated in these were the first-winter
bird in the Sibley guide and the winter adult in the Birds of Europe (which
does not illustrate a first-winter bird).
The distinctions between these images are subtle and few. First, Sibley's
first-winter bird shows a more noticeable secondary bar (less prominent than
in juvenile) than does his "adult nonbreeding" (which has little or none),
shows a distinctly dusky cast to the outer three primaries (no such cast in
nonbreeding adult in Sibley but *distinctly* shown in the winter adult in the
Mullarney et al. guide), and shows a distinctly white underwing, much like a
juvenile but unlike the winter adult, which shows a very narrow edge of black
where underwing coverts end at the remiges (the greater underprimary and
undersecondary coverts are tipped black). Unlike in the juvenile bird, of
course, the back (mantle/scapulars) of the older birds is not contrastingly
dark but pale gray, concolorous with most of the upperwing surface.
When studying the Chincoteague White-winged Tern, we agreed that its basic
pigmentation above was a chalky whitish-gray, much paler than any of the
Black Terns assembled, and that its three outer primaries (and their greater
upperprimary coverts) consistently appeared distinctly duskier than the inner
primaries, which appeared "neat" and paler gray, as with the overall color of
most upperwing coverts. This difference in pigmentation probably indicates
wing molt, but if so, the molt was arrested, as none of the remiges appeared
to be growing in or missing. The condition of the uppersecondary coverts was
apparently transitional; the look of slight dishevelment here was probably
due to wear in these feathers, or possibly some of these being new feathers,
others older. A distinct secondary bar was consistently noticeable, as was a
less distinct dusky leading edge to the upperwing (cubital bar: the lesser if
not the marginal coverts), which did not join the dusky primaries at the
carpal joint.
The bird's back was of a tone with the gray upperwing and contrasted to
varying degrees with the whitish or pale grayish rump (the contrast of course
was not nearly so stark as in juvenile White-wingeds). Under some angles,
the contrast between back and rump was not obvious, but this is consistent
with the literature on nonjuvenile White-winged Tern in basic plumages. As
with the greater/median upperwing coverts, the birds' back feathers and
scapulars did not appear to be altogether fresh, at least when studied at
closest range. The overall impression was of color, in fact, was closer to
some of the adjacent, also foraging Forster's Terns in Swan Cove, rather than
to the Black Terns, and several times observers who looked away from the bird
got back onto the wrong bird, usually Forster's rather than Black Tern.
The White-winged Tern was essentially all white below. Though in strong
light one could see, ventrally, a bit of the upperwing's subtly contrasting
areas, for the most part the bird appeared white below, lacking from all
angles and approaches the dusky bar or spot or block or streak (where the
leading edge of the wing meets the body) of Black Tern and lacking Black's
variable dusky markings along the body where the body plumage meets the
axillaries and the trailing edge of the wings. Though fewer than one in 100
White-winged Terns can apparently show a small mark at the side of the breast
(always smaller than Black Tern's), Black Terns do not lack this mark. As
noted above, the underwing coverts lacked the dark tips associated with at
least some White-winged Terns in definitive basic plumage (more on this
below).
The White-winged's tail was a pale gray, much the same color as the back, a
bit darker than the rump. No molt was observed in the tail, and the bird
never provided a good angle for determining whether the outer webs of outer
rectrices were paler than the remainder of the tail.
In short, nothing about the bird suggested Black (including nominate Black)
or Whiskered Tern, and the bird differed from presumably typical September
adult White-winged Tern in a few subtle ways: the purely pale underwing
coverts; the secondary bar and subtler cubital bar; and possibly (if one
looks only to Sibley's illustration only) the presence of three darker outer
primaries, which, however are illustrated as typical of a winter adult in the
Mullarney et al. guide and are mentioned in Terns of Europe and North America
by K. M. Olsen and H. Larsson (Princeton, 1995).
Unfortunately, this bird was never observed at rest, and so its leg length
relative to other terns (and leg color) could not be studied. The field
characters observed, however, have prompted us to wonder whether this bird
was:
a) an adult (that simply had a pale underwing, without retained black in any
underwing coverts;
b) a "subadult" (first-summer or second-winter) bird, a plumage scarcely
considered in the literature; or
c) a very early example of a first-winter bird.
A caution: the account on White-winged Tern in the Handbook of Australian,
New Zealand, and Antarctic Birds (Higgins, P. J., and S. J. J. F. Davies,
eds. 1996. Oxford. Vol. 3) warns that these three plumages are potentially
"inseparable" (page 776). But other references attempt to describe, if not
fully to distinguish them. Several articles were helpful in beginning to
consider the age of this bird.
1) Alstrom, Per. 1989. Identification of marsh terns in juvenile and
winter plumages. British Birds 82: 296-319.
One the matter of the underwing's appearance in winter-plumage adults, this
article cites communication from A. R. Dean to the effect that "White-winged
Black Terns in otherwise full [ad.] winter plumage often show a little black
on the underwing coverts," (page 318), which suggests that some
winter-plumaged individuals show no black here. The Olsen/Larsson guide does
not discuss the frequency of the mark; it notes that "many [adults in winter
plumage] show diagnostic black bar across underwing" and "some greater
underwing-coverts may be retained, or have black tips in winter" (page 161).
Also, in the photographic plates, #193's caption reads, "Note retained black
greater [underwing] coverts in good contrast to rest of underwing. Such dark
lines may be retained during winter, and are then diagnostic for White-winged
Black" (no page number). Other references echo this sense of the frequency
of this mark. So it would seem that by no means all adult White-winged Terns
show this mark in full definitive basic plumage (our friends in South Africa
and Australia could probably comment on this aspect readily; my experience
with the species in northeastern South Africa is limited to a single rainy
afternoon).
The Alstrom article also notes: "First-winters can be told from adults *so
long as* they retain at least some juvenile wing or tail feathers.
Second-calendar year birds remain in 'winter plumage' throughout spring and
summer; full breeding plumage is not attained until spring of the third
calendar year," the piece continues. [This is not in full agreement with
other texts, which note development of partial adult-like plumage in some
birds in the second calendar year.]
This article also notes that "rarely, at least White-winged Black can be in
full first-winter plumage as early as mid-September; according to Cramp
(1985), moult of the primaries starts in late November to early February"
(page 286).
2) Indeed, "Early acquisition of first-winter plumage by White-winged Black
Tern" is the subject of a note by K. Reid in British Birds 81: 398. The bird
in question was noted on 14 September 1986 at Dungeness, Kent, and was
initially aged as an adult in winter plumage, as it lacked the conspicuous
dark "saddle". "It was, however, a first-winter individual, as indicated by
its extensively grey 'saddle', some remaining blackish lower scapulars, fresh
juvenile wing pattern, and relatively dark (dusky grey) tail."
The typical molt schedule of White-winged Tern would suggest that the bird at
Chincoteague was likely *not* in its first calendar year; the appearance of
the bird would seem to confirm that. Because I can find no mention of an
early September White-winged Tern in full first-winter plumage, I think it's
very unlikely that the bird was in such a plumage. Moreover, had the bird
been in such a plumage, the transitional state of the primaries and upperwing
coverts (and probably mantle/scapulars) would have shown some remnants of
juvenal plumage, which they did not on the Chincoteague bird. Our remoteness
on the East Coast from breeding areas of White-winged Tern further decreases,
in my opinion, the likelihood of such a plumage being seen here.
3) Another short note in British Birds (75: 129-131) by G. Bundy in 1982,
"Field characters of first-year [that is, year-old] White-winged Black Te
rns," attempts to remedy the literature's lacuna on plumages of ca.
one-year-old White-winged Terns with observations in Saudi Arabia from May to
August. The rough sketch of a first-summer bird is essentially identical to
Sibley's first-winter bird (as the Alstrom article suggests would be the
case), with outer primaries duskier, a noticeable secondary bar (mentioned in
the text as a consistent feature at this age), and a lighter cubital bar.
"The first-summer individuals are like winter-plumaged adults, being
essentially pale grey above and white below," according to the text (page
130); one distinction from at least some winter adults is the purely pale
underwing coverts (though the author observed two younger birds with "some
blackish 'smudges'" here), another being the strong secondary bar. "The rump
and tail usually look concolorous with the pale grey upperparts," according
to the text (page 131)-quite different from most field guides' unswerving
emphasis on a starkly contrasting white rump.
4) Turning to Birds of the Western Palearctic, Vol. 4, one reads: "FIRST
WINTER. Plumage change inadequately studied but some moult erratically or
suffer unusual wear and fading. When body plumage renewed, dark 'saddle'
completely lost and head on some noticeably pale, but separation from adults
still allowed by retention of worn juvenile wing-feathers (often showing
complete dusky rim from primary coverts round wing-tip to tertials, and paler
greater coverts) and duller grey, virtually square tail. No records of
'portlandica'-type plumage pattern-this clearly related to initial paleness
of upperwing. SUBSEQUENT PLUMAGES. In first summer and second winter (spent
in Africa), resembles winter adult; may show small incidence of breeding
plumage (e. g., partially black under-wing coverts) in first summer, but not
fully acquired until second spring."
The Handbook of Australian, New Zealand, and Antarctic Birds (HANZAB) depicts
a marvelous "first austral autumn" [that is, almost first-summer] bird on
Plate 44 (page 704) that matches precisely the above BWP description for
FIRST WINTER. All primary coverts are dark in the illustration, unlike in
the Chincoteague bird, which showed a break of gray at the wrist between the
less-pronounced cubital bar and the dusky gray primaries and greater
upperprimary coverts.
5) In The Handbook of Bird Identification for Europe and the Western
Palearctic (Beaman, M. and S. Madge. 1998. Princeton), first-winter plumage
is illustrated both dorsally and ventrally, and the differences from adult
winter would appear to be as follows: duskier gray tail; noticeable secondary
bar; more prominent cubital bar. The "dusky rim" described in BWP is not
illustrated nearly so starkly or neatly as in HANZAB. The illustration also
shows dark-mottled scapulars, a trace of the juvenile's dark back, in other
words (as per Bundy 1982). Thus, the contrast of white rump is greater in
the first-winter bird than in the winter adult illustrated. The underwing of
the first-winter bird is shown to be entirely white in the coverts; the
underwing coverts of the adult in winter are not illustrated here. The text
is silent on plumages other than those of adult and juvenile.
In the absence of any trace of juvenal plumage on the Chincoteague bird,
first-winter plumage would seem pretty firmly ruled out in its case; however,
a bird in first-summer (and/or in transition to second-winter) plumage is
still quite conceivable. The only text to treat this plumage in any detail
is the Olsen/Larsson Terns guide, which reads:
"First-winter/first-summer plumage (and second-winter plumage): Much as adult
winter plumage. In first summer like worn adult winter, but outer primaries
(up to 5) grey-brown from wear. Head and body normally in winter plumage,
but elements of black may be present on body and underwing-coverts. Some
juvenile wing-coverts may be retained. Moults to winter plumage later than
adults. Worn outer primaries can be present up to December-January in second
winter" (page 163).
Photographs of most of these plumages are elusive, and none have been
especially helpful (images of perched birds communicate nothing about the
underwing and upperwing patterns). I'll list out the ones I have found.
1) In the Olsen/Larsson book, photograph #196 depicts a first-summer bird
with "moult in inner primaries" in late August (apparently fresh inner
primaries versus worn outer primaries).
2) In the Olsen/Larsson book, photograph #198 shows several first-winter
birds perched with juveniles in October.
3) Japanese book (page 290). A resting bird that appears to be a little over
a year old, in a photograph taken 17 August 1991.
4) The Elkhorn Slough, California bird is shown in photos at the following
websites:
<http://montereybay.com/creagrus/MTY_rare.html>
<http://fog.ccsf.cc.ca.us/~jmorlan/wwte.htm>
This bird was discovered 6 September 1999, the same date as the Chincoteague
bird, though there is some sentiment that the California bird might have been
present a bit earlier. (I and others had been checking Chincoteague with
some consistency in August, and I believe the White-winged Tern probably
arrived some time during the last few days of August or first few days of
September.)
The age given on the California bird was "molting out of its first summer"
(Roberson website) and "first-summer plumage" (Campbell, C. 2000. Possible
Anywhere: White-winged Tern. Birding 32: 216-230.), and this would appear to
be correct (see image published in Campbell 2000.). The differences of this
bird from the bird at Chincoteague would appear to be: 1) the California bird
had an enormous bill by comparison, much closer to a Black Tern's bill (the
eastern Asian White-winged Terns have larger bills than do White-winged Terns
nesting in eastern Europe); 2) the bird appears to be in molt of just about
all remiges, rectrices, and coverts, and the overall appearance is much less
starkly chalky-pale than the Chincoteague bird (though most of the web-posted
photographs are blurry and quite variable in appearance); and 3) the black on
the ear coverts is much more extensive than on the Chincoteague bird, more
like Black Tern. Otherwise, the bird makes a crude match for the
Chincoteague bird, which however seemed to be a bit "neater" in plumage.
From all this, I tend to favor ageing the Chincoteague bird as a
second-winter bird, a bit more advanced than the California bird in all
likelihood but sharing with it the secondary and cubital bars (more typical
of nonadult birds), the pale underwing (probably more likely in September in
a nonadult bird), and relatively pale gray tail (paler than in juvenal and
first-winter plumages, possibly). Thus the bird showed tendencies of both
first-winter plumage and adult winter plumage, at least as most references
depict these plumages, and the bird was consistent with the few descriptions
of second-winter plumage in print. However, with the materials available and
the study we had of the bird, I cannot really rule out an adult in winter
plumage but lacking retained black tip on greater underwing coverts, a
plumage that would seem far more likely in our context, given the migrational
strategies of the species. Nevertheless, the complete absence of traces of
black plumage, especially in the underwing, makes me lean toward a
second-winter bird.
Ned Brinkley
Cape Charles, Virginia USA
[ << | >> | ^^ ]
Subject: Re: White-winged Tern ageing / RFI
From: Colin Bradshaw <drcolin.bradshaw(AT)BTINTERNET.COM>
Date: 5 Oct 2002 10:09am
Ned,
You may wish to look at the Sept issue of British Birds that has an article
on a White-winged [Black] Tern on 5th Sept in predominantly 1st basic
plumage. There are a series of beautiful illustrations by John Wright who
found and identified this bird. It shows not only that this p[lumage can
occur early but also just how a superb field record should be presented
Cheers
Colin
-----Original Message-----
From: NBHC ID-FRONTIERS Frontiers of Field Identification
[mailto:BIRDWG01(AT)listserv.arizona.edu]On Behalf Of Ned Brinkley
Sent: 05 October 2002 17:22 PM
To: BIRDWG01(AT)listserv.arizona.edu
Subject: [BIRDWG01] White-winged Tern ageing / RFI
The recent visit of a White-winged Tern to Chincoteague National Wildlife
Refuge, Accomack County, Virginia, 6-9 September 2002 should probably get a
little more discussion than it has had on the Internet, inasmuch as the bird
was neither in juvenal plumage nor, possibly, in typical adult basic
plumage,
and too because the species is rarely seen in North America in recent years.
My attempts to get to the bottom of how to age this White-winged Tern have
not ended, and I welcome thoughts on the subject from experienced observers
here. I should acknowledge the help of Jonathan Alderfer, who has provided a
great deal of background material and obscure literature in the past weeks.
I do have access to much relevant literature, but I do not have access to
the
following articles, all of which probably have some important clues or
photographs of relevant plumages (apologies for the absence of diacritical
marks and italics):
Doherty, P. 1989. Ageing of White-winged Tern. Birding World 2: 328-329.
Olsen, K. M. 1989. Art- och alderbestamning av Chlidonias-tarnor
[Identification and ageing of Chlidonias terns]. Parts 1 and 2. Calidris
18: 11-20 & 165-170.
Breife, B. 1991. Svarttarna och vitvingad tarna i vinterdrakt [Black Tern
and White-winged Tern in winter plumage]. Calidris 20: 90.
van IJzendoorn, E. J. and J. D. de Miranda. 1980. Over verenkleden van
Witvleugelstern in september [On plumages of White-winged Tern in
September].
Dutch Birding 2: 62-64.
van IJzendoorn, E. J. and J. D. de Miranda. 1980. Onvolledig zomerkleed
bij Witvleugelstern [Incomplete alternate plumage in White-winged Tern].
Dutch Birding 1: 108.
If anyone has easy access to these articles and is willing to photocopy and
mail them, I'll gladly reimburse the effort in whatever way seems best [the
address here is 9 Randolph Avenue, Cape Charles, Virginia, USA 23310]. I
assume that the Olsen article's contents are incorporated, for the most
part,
in his book with Hans Larsson (Terns of Europe and North America; see
below).
+++++++
Background
I found the bird in company with 6 or 7 Black Terns at Swan Cove on the
refuge, in the afternoon of 6 September 2002. I first observed the bird at
about 1415 EDST, then not again until 1530. Total observation time was
about
20-25 minutes at distances of 40-200 m with a Swarovski scope fitted with
30x
wide eyepiece. Light was excellent at all times. Comparisons with Black
Tern were relatively easy, though the bird did not appear especially to
associate with or forage in concert with Black Terns. As were the Black
Terns, the White-winged was in flight and apparently foraging during all
observations. Like the Blacks, it flew along the edgse of Swan Cove, mostly
the western and northern sides, about 4-10 m above the water as it watched
the water's surface, occasionally dipping (not diving) to the surface in
apparent attempts to seize prey. The bird's behavior while present did lend
permit photography. The bird did not call during the observation at close
range.
The bird was also seen by Tom Pendleton and Ben Copeland during the second
observation; later in the day, Fenton Day, Bev Leeuwenburg, Larry Lynch,
Bill
Akers, and many others saw it (a state ornithological meeting commenced
there
that afternoon). On the next day, an observer from New Jersey saw it, also
in the afternoon. On the 8th, Mike and Dixie Overton, Todd Day, Sue Heath,
Jon Little, and Grayson Pearce observed the bird. On the 9th, I looked for
the bird in the afternoon unsuccessfully, but earlier, at 1300, Michael
Retter and Nick Block found the bird, again in Swan Cove. That was the
final
observation of the bird; a cold front apparently ushered it and the Black
Terns off to parts unknown on the following day. Though a few Black Terns
can linger in this region until the first days of October (as one juvenile
did in 2000), most coastal birds depart by mid-September, about the same
time
the last Least Terns depart.
In direct comparison with Black Terns (both juveniles and adults), the
White-winged showed a different overall shape, bill proportions, appearance,
and flight behavior.
1) The bird's black bill was obviously, noticeably slight in comparison to
those of the Black Terns, certainly shorter than those of nearby Black
Terns.
It was really astonishing to me how visible the difference was at distances
even over 100 m.
2) The proportions and shape of the White-winged Tern were also
consistently,
rather strikingly different from the Black Terns'. The birds' wings were
less sharply pointed at the tip, and perhaps (proportionately) slightly
wider
than those of the Black Terns. The tail was not noticeably forked but
appeared rather square-ended at most distances; a very slight difference
between outer and inner rectrix length was barely perceivable at closest
range, but this never produced the impression of a "forked" tail.
3) Flight style of the bird was rather like the Black Terns', but the bird's
wingstrokes were a bit shallower, its moves less darting, swooping, and
nimble on the whole, appearing more "methodical" and less swallowlike.
4) The body of the bird appeared more robust than those of the apparently
slenderer Black Terns; overall, the bird appeared a bit "stumpier" than the
Blacks and smaller by a bit.
The bird's rather starkly white head showed clear, small dark patches of
black at the ear coverts, joined tentatively by a little grayish stippling
over the mid-crown that narrowed and tapered off at the central upper
hindcrown. The nape/collar was starkly white, like the rest of the head.
The overall impression of the white-looking head (and indeed the overall
impression of the bird), with its small bill and almost doll-like,
round-headed jizz, was that of a Little Gull in basic plumage, with its
large
dark eye surrounded entirely by white (no dark in the lores) and the
impression, at most distances, of simply dark ear covert spots. This in an
oft-cited comparison in the identification literature on this species and is
surprisingly apt.
Dorsal and ventral plumage.
Just to serve as points of reference, I'll mention two texts familiar to
subscribers on this service: the Sibley Guide to birds of North America, and
the Mullarney/Svensson/Zetterstrom/Grant Birds of Europe. Tom Pendleton and
I made reference to these while watching the bird in the field and making
notes, and the closest plumages illustrated in these were the first-winter
bird in the Sibley guide and the winter adult in the Birds of Europe (which
does not illustrate a first-winter bird).
The distinctions between these images are subtle and few. First, Sibley's
first-winter bird shows a more noticeable secondary bar (less prominent than
in juvenile) than does his "adult nonbreeding" (which has little or none),
shows a distinctly dusky cast to the outer three primaries (no such cast in
nonbreeding adult in Sibley but *distinctly* shown in the winter adult in
the
Mullarney et al. guide), and shows a distinctly white underwing, much like a
juvenile but unlike the winter adult, which shows a very narrow edge of
black
where underwing coverts end at the remiges (the greater underprimary and
undersecondary coverts are tipped black). Unlike in the juvenile bird, of
course, the back (mantle/scapulars) of the older birds is not contrastingly
dark but pale gray, concolorous with most of the upperwing surface.
When studying the Chincoteague White-winged Tern, we agreed that its basic
pigmentation above was a chalky whitish-gray, much paler than any of the
Black Terns assembled, and that its three outer primaries (and their greater
upperprimary coverts) consistently appeared distinctly duskier than the
inner
primaries, which appeared "neat" and paler gray, as with the overall color
of
most upperwing coverts. This difference in pigmentation probably indicates
wing molt, but if so, the molt was arrested, as none of the remiges appeared
to be growing in or missing. The condition of the uppersecondary coverts
was
apparently transitional; the look of slight dishevelment here was probably
due to wear in these feathers, or possibly some of these being new feathers,
others older. A distinct secondary bar was consistently noticeable, as was
a
less distinct dusky leading edge to the upperwing (cubital bar: the lesser
if
not the marginal coverts), which did not join the dusky primaries at the
carpal joint.
The bird's back was of a tone with the gray upperwing and contrasted to
varying degrees with the whitish or pale grayish rump (the contrast of
course
was not nearly so stark as in juvenile White-wingeds). Under some angles,
the contrast between back and rump was not obvious, but this is consistent
with the literature on nonjuvenile White-winged Tern in basic plumages. As
with the greater/median upperwing coverts, the birds' back feathers and
scapulars did not appear to be altogether fresh, at least when studied at
closest range. The overall impression was of color, in fact, was closer to
some of the adjacent, also foraging Forster's Terns in Swan Cove, rather
than
to the Black Terns, and several times observers who looked away from the
bird
got back onto the wrong bird, usually Forster's rather than Black Tern.
The White-winged Tern was essentially all white below. Though in strong
light one could see, ventrally, a bit of the upperwing's subtly contrasting
areas, for the most part the bird appeared white below, lacking from all
angles and approaches the dusky bar or spot or block or streak (where the
leading edge of the wing meets the body) of Black Tern and lacking Black's
variable dusky markings along the body where the body plumage meets the
axillaries and the trailing edge of the wings. Though fewer than one in 100
White-winged Terns can apparently show a small mark at the side of the
breast
(always smaller than Black Tern's), Black Terns do not lack this mark. As
noted above, the underwing coverts lacked the dark tips associated with at
least some White-winged Terns in definitive basic plumage (more on this
below).
The White-winged's tail was a pale gray, much the same color as the back, a
bit darker than the rump. No molt was observed in the tail, and the bird
never provided a good angle for determining whether the outer webs of outer
rectrices were paler than the remainder of the tail.
In short, nothing about the bird suggested Black (including nominate Black)
or Whiskered Tern, and the bird differed from presumably typical September
adult White-winged Tern in a few subtle ways: the purely pale underwing
coverts; the secondary bar and subtler cubital bar; and possibly (if one
looks only to Sibley's illustration only) the presence of three darker outer
primaries, which, however are illustrated as typical of a winter adult in
the
Mullarney et al. guide and are mentioned in Terns of Europe and North
America
by K. M. Olsen and H. Larsson (Princeton, 1995).
Unfortunately, this bird was never observed at rest, and so its leg length
relative to other terns (and leg color) could not be studied. The field
characters observed, however, have prompted us to wonder whether this bird
was:
a) an adult (that simply had a pale underwing, without retained black in any
underwing coverts;
b) a "subadult" (first-summer or second-winter) bird, a plumage scarcely
considered in the literature; or
c) a very early example of a first-winter bird.
A caution: the account on White-winged Tern in the Handbook of Australian,
New Zealand, and Antarctic Birds (Higgins, P. J., and S. J. J. F. Davies,
eds. 1996. Oxford. Vol. 3) warns that these three plumages are
potentially
"inseparable" (page 776). But other references attempt to describe, if not
fully to distinguish them. Several articles were helpful in beginning to
consider the age of this bird.
1) Alstrom, Per. 1989. Identification of marsh terns in juvenile and
winter plumages. British Birds 82: 296-319.
One the matter of the underwing's appearance in winter-plumage adults, this
article cites communication from A. R. Dean to the effect that "White-winged
Black Terns in otherwise full [ad.] winter plumage often show a little black
on the underwing coverts," (page 318), which suggests that some
winter-plumaged individuals show no black here. The Olsen/Larsson guide
does
not discuss the frequency of the mark; it notes that "many [adults in winter
plumage] show diagnostic black bar across underwing" and "some greater
underwing-coverts may be retained, or have black tips in winter" (page 161).
Also, in the photographic plates, #193's caption reads, "Note retained black
greater [underwing] coverts in good contrast to rest of underwing. Such
dark
lines may be retained during winter, and are then diagnostic for
White-winged
Black" (no page number). Other references echo this sense of the frequency
of this mark. So it would seem that by no means all adult White-winged
Terns
show this mark in full definitive basic plumage (our friends in South Africa
and Australia could probably comment on this aspect readily; my experience
with the species in northeastern South Africa is limited to a single rainy
afternoon).
The Alstrom article also notes: "First-winters can be told from adults *so
long as* they retain at least some juvenile wing or tail feathers.
Second-calendar year birds remain in 'winter plumage' throughout spring and
summer; full breeding plumage is not attained until spring of the third
calendar year," the piece continues. [This is not in full agreement with
other texts, which note development of partial adult-like plumage in some
birds in the second calendar year.]
This article also notes that "rarely, at least White-winged Black can be in
full first-winter plumage as early as mid-September; according to Cramp
(1985), moult of the primaries starts in late November to early February"
(page 286).
2) Indeed, "Early acquisition of first-winter plumage by White-winged Black
Tern" is the subject of a note by K. Reid in British Birds 81: 398. The
bird
in question was noted on 14 September 1986 at Dungeness, Kent, and was
initially aged as an adult in winter plumage, as it lacked the conspicuous
dark "saddle". "It was, however, a first-winter individual, as indicated by
its extensively grey 'saddle', some remaining blackish lower scapulars,
fresh
juvenile wing pattern, and relatively dark (dusky grey) tail."
The typical molt schedule of White-winged Tern would suggest that the bird
at
Chincoteague was likely *not* in its first calendar year; the appearance of
the bird would seem to confirm that. Because I can find no mention of an
early September White-winged Tern in full first-winter plumage, I think it's
very unlikely that the bird was in such a plumage. Moreover, had the bird
been in such a plumage, the transitional state of the primaries and
upperwing
coverts (and probably mantle/scapulars) would have shown some remnants of
juvenal plumage, which they did not on the Chincoteague bird. Our
remoteness
on the East Coast from breeding areas of White-winged Tern further
decreases,
in my opinion, the likelihood of such a plumage being seen here.
3) Another short note in British Birds (75: 129-131) by G. Bundy in 1982,
"Field characters of first-year [that is, year-old] White-winged Black Te
rns," attempts to remedy the literature's lacuna on plumages of ca.
one-year-old White-winged Terns with observations in Saudi Arabia from May
to
August. The rough sketch of a first-summer bird is essentially identical to
Sibley's first-winter bird (as the Alstrom article suggests would be the
case), with outer primaries duskier, a noticeable secondary bar (mentioned
in
the text as a consistent feature at this age), and a lighter cubital bar.
"The first-summer individuals are like winter-plumaged adults, being
essentially pale grey above and white below," according to the text (page
130); one distinction from at least some winter adults is the purely pale
underwing coverts (though the author observed two younger birds with "some
blackish 'smudges'" here), another being the strong secondary bar. "The
rump
and tail usually look concolorous with the pale grey upperparts," according
to the text (page 131)-quite different from most field guides' unswerving
emphasis on a starkly contrasting white rump.
4) Turning to Birds of the Western Palearctic, Vol. 4, one reads: "FIRST
WINTER. Plumage change inadequately studied but some moult erratically or
suffer unusual wear and fading. When body plumage renewed, dark 'saddle'
completely lost and head on some noticeably pale, but separation from adults
still allowed by retention of worn juvenile wing-feathers (often showing
complete dusky rim from primary coverts round wing-tip to tertials, and
paler
greater coverts) and duller grey, virtually square tail. No records of
'portlandica'-type plumage pattern-this clearly related to initial paleness
of upperwing. SUBSEQUENT PLUMAGES. In first summer and second winter
(spent
in Africa), resembles winter adult; may show small incidence of breeding
plumage (e. g., partially black under-wing coverts) in first summer, but not
fully acquired until second spring."
The Handbook of Australian, New Zealand, and Antarctic Birds (HANZAB)
depicts
a marvelous "first austral autumn" [that is, almost first-summer] bird on
Plate 44 (page 704) that matches precisely the above BWP description for
FIRST WINTER. All primary coverts are dark in the illustration, unlike in
the Chincoteague bird, which showed a break of gray at the wrist between the
less-pronounced cubital bar and the dusky gray primaries and greater
upperprimary coverts.
5) In The Handbook of Bird Identification for Europe and the Western
Palearctic (Beaman, M. and S. Madge. 1998. Princeton), first-winter
plumage
is illustrated both dorsally and ventrally, and the differences from adult
winter would appear to be as follows: duskier gray tail; noticeable
secondary
bar; more prominent cubital bar. The "dusky rim" described in BWP is not
illustrated nearly so starkly or neatly as in HANZAB. The illustration also
shows dark-mottled scapulars, a trace of the juvenile's dark back, in other
words (as per Bundy 1982). Thus, the contrast of white rump is greater in
the first-winter bird than in the winter adult illustrated. The underwing
of
the first-winter bird is shown to be entirely white in the coverts; the
underwing coverts of the adult in winter are not illustrated here. The text
is silent on plumages other than those of adult and juvenile.
In the absence of any trace of juvenal plumage on the Chincoteague bird,
first-winter plumage would seem pretty firmly ruled out in its case;
however,
a bird in first-summer (and/or in transition to second-winter) plumage is
still quite conceivable. The only text to treat this plumage in any detail
is the Olsen/Larsson Terns guide, which reads:
"First-winter/first-summer plumage (and second-winter plumage): Much as
adult
winter plumage. In first summer like worn adult winter, but outer primaries
(up to 5) grey-brown from wear. Head and body normally in winter plumage,
but elements of black may be present on body and underwing-coverts. Some
juvenile wing-coverts may be retained. Moults to winter plumage later than
adults. Worn outer primaries can be present up to December-January in
second
winter" (page 163).
Photographs of most of these plumages are elusive, and none have been
especially helpful (images of perched birds communicate nothing about the
underwing and upperwing patterns). I'll list out the ones I have found.
1) In the Olsen/Larsson book, photograph #196 depicts a first-summer bird
with "moult in inner primaries" in late August (apparently fresh inner
primaries versus worn outer primaries).
2) In the Olsen/Larsson book, photograph #198 shows several first-winter
birds perched with juveniles in October.
3) Japanese book (page 290). A resting bird that appears to be a little
over
a year old, in a photograph taken 17 August 1991.
4) The Elkhorn Slough, California bird is shown in photos at the following
websites:
<http://montereybay.com/creagrus/MTY_rare.html>
<http://fog.ccsf.cc.ca.us/~jmorlan/wwte.htm>
This bird was discovered 6 September 1999, the same date as the Chincoteague
bird, though there is some sentiment that the California bird might have
been
present a bit earlier. (I and others had been checking Chincoteague with
some consistency in August, and I believe the White-winged Tern probably
arrived some time during the last few days of August or first few days of
September.)
The age given on the California bird was "molting out of its first summer"
(Roberson website) and "first-summer plumage" (Campbell, C. 2000. Possible
Anywhere: White-winged Tern. Birding 32: 216-230.), and this would appear
to
be correct (see image published in Campbell 2000.). The differences of this
bird from the bird at Chincoteague would appear to be: 1) the California
bird
had an enormous bill by comparison, much closer to a Black Tern's bill (the
eastern Asian White-winged Terns have larger bills than do White-winged
Terns
nesting in eastern Europe); 2) the bird appears to be in molt of just about
all remiges, rectrices, and coverts, and the overall appearance is much less
starkly chalky-pale than the Chincoteague bird (though most of the
web-posted
photographs are blurry and quite variable in appearance); and 3) the black
on
the ear coverts is much more extensive than on the Chincoteague bird, more
like Black Tern. Otherwise, the bird makes a crude match for the
Chincoteague bird, which however seemed to be a bit "neater" in plumage.
>From all this, I tend to favor ageing the Chincoteague bird as a
second-winter bird, a bit more advanced than the California bird in all
likelihood but sharing with it the secondary and cubital bars (more typical
of nonadult birds), the pale underwing (probably more likely in September in
a nonadult bird), and relatively pale gray tail (paler than in juvenal and
first-winter plumages, possibly). Thus the bird showed tendencies of both
first-winter plumage and adult winter plumage, at least as most references
depict these plumages, and the bird was consistent with the few descriptions
of second-winter plumage in print. However, with the materials available
and
the study we had of the bird, I cannot really rule out an adult in winter
plumage but lacking retained black tip on greater underwing coverts, a
plumage that would seem far more likely in our context, given the
migrational
strategies of the species. Nevertheless, the complete absence of traces of
black plumage, especially in the underwing, makes me lean toward a
second-winter bird.
Ned Brinkley
Cape Charles, Virginia USA
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