The First-Winter Thayer's/Kumlien's
Ned Brinkley (esb4n@virginia.edu):
I think the first-winter Thayer's is a Kumlien's -- the tailband and secondary bar are diffuse, the tertials not solid-centered, and the primary pattern very weak. I don't think wear at this point could make all that much difference. The bird's structure could indicate either, though I agree it's more Thayer's-like, but this is not entirely settled as a field character (cf. the latest grenade-lobbing fests between McGeehan and Howell in BIRDING WORLD).
Lyn Atherton (bonnie@cftnet.com):
I think the gull is a very worn Thayer's. It seems a bit too "bulky" for Kumlien's and the rectrices seem too dark. The plumage of this bird is not too pale for very worn Thayer's at that date. The three Kumlien's I've seen in FL had some very faint barring on the rectrices but were otherwise the color of the primaries which were cream-colored. On 11 June 1983, I identified a severely feather-worn, bleached out gull at Port St. Joe, FL as Thayer's. The shafts of all flight feathers were bare and, of course, the bird was unable to fly any significant distance. The following day I returned with Henry Stevenson who collected the gull. Its identity as Thayer's was confirmed by Godfrey. Even though when I first saw the bird it appeared to be similar in color to Kumlien's, the slightly more "bulky" appearance convinced me that it was Thayer's.
[later message]
Just checked the slides of the 11 June 1983 Thayer's collected on 12
June and confirmed as Thayer's by Godfrey. The underwing lining is
virtually identical to that of your bird. And the entire bird is so
worn, there's no doubt the tertials are "white." Your photo #3 seems to
show the color of the tertials best. There appears to be a significant
amount of dark in the center of at least one of them. I checked some of
my other photos of first-winter Thayer's. The tertials of your bird are
consistent with those of several I have photographed. There is
considerable variation in the plumages of the first-winter Thayer's I've
seen. I have seen and photographed from probably the palest (would have
been in Kumlien's range but was too big, I think) to very dark birds
with quite dark primaries. It seems that the light/dark of the tertials
is relative to the light/dark of the primaries. I can't see any problem
with your bird being Thayer's, especially with the amount of dark in the
secondaries and rectrices.
Dick Newell (Dick.Newell@Smallworld.co.uk):
I am nothing like as experienced with Thayer's/Kumlein's. However, I think I would vote for Kumlein's on this, even thought the bill looks a bit large and the head is not "cute" enough. I suppose I have seen about 10 1st year Thayer's in the last 10 years, 2 in April this year, one in Colorado and one in California - of which I got some great photos. I have seen rather more Kumlein's/Icelands including 2 adult Kumlein's that I found last winter here in the UK. In my experience, 1stW Thayer's looks anything between a pale Herring Gull and a dirty Iceland Gull. The one consistent feature seams to be that the underside of the primaries are translucent white with obvious darker tips. The California bird that I saw was of the dirty Iceland Gull type, looking cute, especially when feeding from my hand! However, perched, its primaries were dark lacking any pale edges (probably worn off). Your bird's body and wings just look too pale for Thayer's to me, especially the upper side of the primaries and the underside of the primaries do not have dark tips. There is something about the tail band that is not quite solid enough to my eye - but I agree that bill is a bit large, but it's not Thayer's shaped either.
Lyn Atherton (bonnie@cftnet.com):
There is no doubt in my mind that the gull is a first year Thayer's Gull. I have photos of same-aged Thayer's taken in April at Toytown Landfill (St. Petersburg, Pinellas Co., FL) that are virtually identical to this bird--even down to bill color/pattern. At Toytown, Thayer's normally arrived at the first of January and some remained into March and April. I followed (with the camera) a number of these birds, showing the progression of wear as they stayed into spring. I would bet that the bird had "silvery" underwing and undertail, also.Ned Brinkley (esb4n@virginia.edu):
Though (as you know), I still look at the "Western Gull" photos and look at my own Western Gull photos and think the head and bill look very differently shaped, I am ultimately perplexed by this bird. It's not a matter of not wanting it to be a Western (I do! and I was there, after all!) -- it's just that I can't see it as a typical Western and so have reservations.
[later]
The wingtip pattern surely matches. But the underwing was very, very pale
on the Hatteras bird, with much less dark pigmentation visible in flight
feathers from below than on northern population W. Gulls (which I have a
lot of experience with, though not all that many flight photos of). That
was one of my stated concerns with the bird in the field. The bird in this
photo, too, appears to have a hammer-head and a very heavy bill, esp.
heavy/deep at the gonys, typical of Western Gull.
[later]
I stand by the consensus of observers (.......) who noted, commented on, and more importantly agreed on a
pale underwing like that of adjacent Herrings. If there is a slide to
disprove that, then that's very good news for interpreting this bird as a
Western.
Don Roberson (creagrus@montereybay.com):
Bob, for what it's worth, the Western Gull (?) on your web page doesn't look quite right to me for a Western. It is too small in the body (compared to Herrings), the bill looks both actually & proportionately too thin & small; and the head shape is a bit odd. If it were a Western, it would have to be a female, but it is still too small overall to my eye. [I see hundreds of Westerns daily here in Monterey]. What I can see of the underwings is all wrong - not nearly enough dark below along the trailing edge - but this could be an artifact of the photo. Any more details on underwing?
Dennis Paulson (dpaulson@mail.ups.edu):
I just looked at all your photos, and I can see no reason whatsoever not to call this a Western Gull. No one could pick this bird out of a flock of Washington Western Gulls. It's fortunate that you have it with Herring and Great Black-backed gulls, as you can get a pretty good idea of the mantle color. It is typical of Western and much too dark for us to consider it a hybrid Western x Glaucous-winged. I'd say it's absolutely not a "West Coast hybrid." If it's got Glaucous-winged genes, they're apparent only in its migratory behavior!The bill looks right for Western, the wingtip looks right, the mantle color looks right. I can't imagine any hybrid between any of the Atlantic gulls that would end up looking like your bird. It looks to be Herring-sized, so a hybrid between Herring and GBB seems unlikely. I wonder if a hybrid between a paler-mantled Lesser Black-backed and a GBB could look something like your bird? At the very least, it should have a very light eye, enough to eliminate it.
Greg Gillson (greg.gillson@tek.com):
Well, your bird is certainly not the northern subspecies, occidentalis. Your bird is way too dark, maybe even too much for the southern wymani.I'm bothered by the small dark eye; the southern race of Western Gull shows a larger pale eye (all are mixed dark and light, but most appear a golden brown or greenish-brown, darker in the north, yellower in the southern subspecies).
Something is strange with the bill. Western's don't show black on the gonys where yours does. It is too short, too blob-ended. It is not orange enough for Western, which show a schoolbus yellow color, not the flat yellow of Herring.
Primaries look better for Western, but Slay-backed might also fit.
In short, I don't think it's a Western Gull. I have nothing to suggest as an alternative, however.
Discussion:
My opinion is that the underwing showed dark gray secondaries, much darker than Herring Gull, though not as dark as Great Black-backed. Apparently I do not have a photo to really prove it. However, on the seventh photo I think that one can see that the secondaries are dark gray, and that they are largely covered by the white underwing coverts. Compare photo 532 in Grant. Had the underwing been as pale as Herring Gull, I never would have submitted it as a Western! So we seem to have an impasse here. I suppose it is conceivable that we are talking about two different birds...??
Dick Newell (Dick.Newell@Smallworld.co.uk):
Your NJ mystery bird - I don't think you can necessarily eliminate 1st W LBBG - although the primary window is rather iffy for LBBG. Michahelis can almost look like it, but I think the mantle and scaps are too dark - also the "feel" of the bird to me is a bit more LBBG than YLG. It looks too dirty for YLG, although I have photos of michahelis which look as dirty. Of the YLG's atlantis is nearest to LBBG, and it may well be this.
[later]
I have spent a lot of time this last winter looking at gulls, especially
LBBG's here in England. I am sure your mystery gull is a LBBG in it's second
winter, but it is in a delayed state of moult. It should have grey mantle
and scapulars and new tertials at this age. The obviously warn wings explain
why there was a window on the inner primaries, many LBBG's show this. The
graellsii grey cast to the back is a common effect. The shape of the bird is
typical of LBBG, the tertials look fine.
Young Lesser Black-backed Gulls are incredibly variable in size, shape, bill
size, bill colour, tail band, whiteness of head, whiteness of underparts,
state of moult, state of wear etc.. We are starting to make some progress
with this after finding that colour ringed birds plumage does not always
look like it should for the age of the bird. We have had 2 year old birds
looking like 3 year olds and also like 1 year olds! At first we thought we
were screwing up on our ageing, but now we realise the birds are that
variable in their moult timing.
Discussion:
Photos of this bird were sent to a European Gull conference in the summer of 1996. The consensus was that it was a first winter bird, probably either Lesser Black-backed, Yellow-legged Gull L. c. atlantis, or an undescribed taxon(!!).
Lyn Atherton (bonnie@cftnet.com):
I finally found time to pull out some of my Lesser Black-backed Gull slides to compare with your bird you photographed at Hatteras. When I saw your photo I immediately felt this was not a pure Lesser Black-backed, and perhaps, not even a hybrid. The first thing that struck me as wrong for L B-b is that the "jizz" is wrong. The body seems too robust, and the bird at rest holds its wings and tail more horizontal with the ground. I have just looked at my photos (taken at Toytown Landfill, St. Petersburg, FL) of 6 different adult L B-b's and at least that many other various aged L B-b's and all hold their tails at about a 30 degree angle with the ground. This is a characteristic I used to point out to beginning gull watchers as another clue (although not at the top of the list) in separating first year L B-b's from same-aged Herrings. I think your bird holds the tail more horizontal because the legs are placed farther back on the body and, perhaps, because of the more robust breast. Whatever, this feature struck me immediately as wrong for L B-b when I viewed your photos. (Notice this feature is consistent in all your photos of the standing bird.)The color of the legs is consistent with those of my adult graellsii as shown in my photos (using Kodachrome 64). However, in life, they do get much brighter yellow legs by March or April.
You said you think the primary extension beyond the tail is too long for graellsii. However, if not the same, it may be slightly shorter than those of my birds (and I believe all these photos of mine are of graellsii). This is what gives this species (at least, graellsii) what I consider a long-winged appearance. The "white wing tips" are about the same as on my birds photographed in January, and, actually, larger than on those photographed in March. But the latter isn't surprising as most of my birds spent their entire winters at this landfill, thus the wing tips would wear more in our warmer winter climate.
You say the bill is not especially massive, but, relative to the overall size of the bird, I consider it too short and deep for L B-b. And maybe it is not in perfect profile, thereby misleading, but it appears there is not a significant gonydal angle. All of my photos show birds with relatively longer and more slender bills with a noticeable gonydal angle.
I noticed the bird's eye appears to have a slightly orange tone (photos #1 and #3). In my photos where eye color can be determined with certainty, the eyes appear quite clear, without an orange tone. Maybe this is another clue to its identity?
Dick Newell (Dick.Newell@Smallworld.co.uk):
At first sight, I cannot see anything wrong with this being a Lesser Black-backed Gull, save the rather small mirror on P10 in one of the flight shots and, more interesting, P10 seems to be not quite fully grown (in March!). These two latter points might suggest heuglini. However, the shape of the bird and the head shape do not seem to look like heuglini to me (judging from photographs). I took a very brief look at a friend's copy of the Alula article last weekend, didn't have time to study in depth, but I did notice a photo of an apparent heuglini that I could not see why it was not a graellsii. I would not rule out LBBG on size. I think your best way forward is to study the Alula article in depth - I have ordered it, but it has not arrived yet.
[later]:
Yesterday (Sat 13th June) I spent 4 hours on
my local dump looking carefully at LBBG's - there were about 400 there - all
graellsii as far as I could make out (sometimes we get a high proportion of
intermedius). The vast majority (in fact all that I looked at) had much
larger mirrors than your bird, mostly on P10 and P9. In fact, nothing quite
matched the heuglini type mirrors of your bird. On many the end of P10 is
wholly white.
Klaus Malling Olsen (kmo@e-box.dk):
Being familiar with Lesser BB and currently working on an ID guide to the Gulls of the Holarctic, I agree with you that the birds in question is a large male lesser. Heuglini and hybrid heuglineXfuscus could be ruled out by the extensive dark brown head-spotting: both heuglini and fuscus are dominantly white-headed in winter with dark marking always as streaks, and comcentrated to hindneck - as necklace. Certain heugnini are more well-marked with streaking (not spotting) even around eyes and in crown.
The puzzling thing about the unusual late moult may be explained in that vagrant gulls often show atypical moult. Theoretically this bird has undergone a much longer migration than normal and thus showed a delayed moult compared to normal graellsii/intermedius, which normally complete their primary moult by November. Moult have been the relevation for gull-watchers, but should be used with care - as always with ID characters.
The bird otherwise fits graellsii well, although it is strange that it shows so little white in p10 and none in p9; this could be expected from a small percentage of graellsii/intermedius, however.
Jim Bangma (jbangma@compuserve.com):
Your two adult Kelps - interesting, possibly the same individual, and it must be the smallest billed, roundest headed dominicanus in the world - unfortunately, that highlights the phenomenon that oddball birds are more likely to be represented in photo collections than normal ones.Next, the baby Kelp - this gets weird, because we have to reverse seasons, and there is a big range in breeding times from north to south. I have always used the rule of thumb that a solid black (or gray) patch on the back usually isn't acquired until the second alternate plumage, and this bird's back isn't solid yet. In Tierra del Fuego in November there were a number of birds with solid black backs, I took these to be in 2nd summer plumage. This bird is photographed in December, but may be from a southern breeding population - my suspicion, although I would like to check Murphy over the weekend, is that it is a somewhat delayed second alternate bird. It certainly is not first year, they do retain a mostly brown plumage, as I recall. I'll get back to you on this one.
Next, the single Olrog's - I've never seen a specimen in that plumage. Nor have I seen a specimen of belcheri or crassirostris resembling that. It seems to have an awful lot of white around the hindneck and body, but it does have a fairly solid mantle. Looking at the next shot, the birds there seem to be in a fairly similar plumage, but with less white - I suspect that whatever they are, this single bird is consistent with them, beginning their moult 3 months later. So, using that as a guideline, and applying what I know of Band and Black-tailed, lets see what we come up with:
Keep in mind that I am of the opinion that these three birds (Both Dwight and Murphy conjectured that the three black-tailed gulls are closely related) are in fact "4 year" gulls. So their plumage sequence should match that of "standard" 4 year birds. First year plumage is basically all brown, I have examined specimens of all three that sort of resemble a juvie->first winter Laughing Gull - rather scaly brown, with white developing around the face, and later down the breast. Second year plumages acquire adult color in the back and generally get a bit whiter overall - I've examined a number of black and band tails in this plumage, but never looked that closely at Olrogs. Third years appear similar to adults - identical at a quick look, hence the impression most authors have that these are 3 year gulls. But whether or not this plumage exists, it doesn't apply to Claudia's bird.
Murphy states that belcheri adults begin their moult to alternate plumage in late July, completing it by early September. I am assuming that Olrog's is about the same (closely related and breeds at about the same latitude). The birds in the following picture (with the Kelp Gull) appear to have black mantles - this would be consistent with 2nd alternate in the other two species, and I see no reason to think it would be different in Olrog's. I am surprised that they are as dark headed as they are - I would expect Black-tailed to be much whiter on the chest and around the head, although I think I recall Belcher's being somewhat darker overall at the same age. If so, that would make the single bird in molt from 2nd alternate to 3nd basic.
What bothers me is the hooded appearance of the bird, more like belcheri.
The mantle appears too dark for that species, and the bill too large, but
are you 100% sure of the location and ID of the photo? Actually, with that
schnoz, I would almost be ready to consider it the Atlantic's first record
of Pacific Gull!
The Longport NJ Possible Yellow-legged Gull
Philippe J. Dubois:
Dear Marvin,I recently received your letter together with 6 photographs of your gull seen at Longport, NJ, last March. I carefully examined them with description and comments from other birdwatchers. First of all, I have to say that I have experience with all the WP Yellow-legged Gull races and a rather good experience with smithsonianus Herring Gull (I recently made an ID paper about this race in British Birds).
To my eyes, this bird is NOT a smithsonianus HG, possibly an atlantis Yellow-legged and more probably a hybrid Herring x Lesser Black-backed Gull.
General shape and structure is not good for a North American HG. The wings look long, well beyond the tail. Legs are not tall, head is round and comparing with ad. smithso, it looks slender, recalling an intermedius Lesser Black-backed.
On the photograph where it is with ad smithso, bluish cast on the mantle is well visible and looks different from the typical grey smithso mantle.
At this stage, I would say that the bird looks like a Yellow-legged Gull, but with more slender proportions, recalling the atlantis race. Wing pattern is very interesting. The amount of black is very important, which is rather strange for any Herring Gull. Black comma on p5 is really not important for an YLG, especially for atlantis which has often some black on p4 too. Interestingly, the black on p6 is present on the outer web of the feather towards the basal part. I have never seen such a pattern on Herring Gull but Yellow-legged (especially atlantis) and Lesser black-backed Gulls do show it.
Since the bird looks in perfect summer plumage with bright orange-yellow bill, it is strange that the legs are yellowish and feet pinkinsh (but beware to bare parts !). It is not in accordance with atlantis. On the other hand, mantle - which has a rather typical YLG bluish cast - is probably too light for atlantis.
These discrepancies lead me to think that the Longport bird is more probably an hybrid between Herring and Lesser Black-backed Gull.
* structure too slender for smithso, recalling LBBG.
* mantle colour with a bluish cast.
* legs with a pinkinsh cast, OK for such an hybrid.
* bill with an orange tinge, a feature showed by LLBG.
* orbital ring.
* wing pattern not in accordance with HG, recalling YLG (atlantis), but
with some discrepancy on p5, or LBBG, but quite possible for an hybrid (see
for example the wing pattern of HG x LBBG hybrid in British Birds 90/1-2,
p.34, 1997).
I don't want to give a 100% answer either way, but this likes to be a good
alternative to other hypothesis.
Pierre Yesou:
To my eyes there is little doubt that this bird really was a Yellow-legged Gull Larus cachinnans, from its overall appearance and stance, its bill (shape and colour), its red eye-ring, its wing-tip and underwing pattern. It should be of the race michahellis from mantle colour (not too dark to my eyes): too pale for atlantis (and not enough dark on primary tips), while nominate cachinnans usually looks more elegant (not always) and shows more white on outer primaries.
The problem with the legs is not an absolute one. In michahellis, most
adult-looking individuals surely show bright orange legs by March, but a
minority doesn't: either they are subadults (and I beleive from two photos
that it might be the case here: check the original photos for a hint of
brown - sign of immaturity - on the grey of inner primaries and on secondary
coverts, which seems to show both in flight and on the ground), or they are
not fit. A colleague kept an injuried michahellis for year in his mother's
garden; it always showed yellow legs, except one winter when the legs were
an odd pink flesh! The other bare parts were normally coloured (i.e. red
eye ring, brightly coloured bill), just to become orange again some months
later and up to the end of its life. Were the temporary fleshy legs an
indication that the bird then was sick/tired/stressed?
Also, when a gull doesn't show its bright leg coloration, it is the usual
way that the feet (mostly the webs) are paler than the leg itself. In
various forms, including nominate cachinnans, it is a quite common
situation even on breeding grounds in spring.
Nick Rossiter (nrossiter@netlineuk.net):
This bird to my mind looks like a typical Yellow-legged Gull from an Atlantic colony. From my studies at a number of sites in the Canaries, Morocco, Portugal and northern Spain, there appears to be what I call a Dark Atlantic Yellow-legged Gull (DAYLG) form, comprising both the traditional atlantis of the Canaries, Azores and Madeira and what has been called michahellis in the past on the Atlantic coasts of Morocco and Portugal. As long ago as 1934 Stegmann had the same view of an extended atlantis range and so does Robert Lewis http://home.bway.net/lewis/birds/Portugal/port.html after seeing Yellow-legged Gulls in Portugal in the field.
Most of the past accounts of atlantis relate to the Azores where the gulls appear to have more black and less white in the wing-tip than that typically found throughout the range of the DAYLG. There are a number of other geographical variations with those in Portugal beginning to show some transition to the paler Cantabricans form found in northern Spain (which is another story).
Basically the Long Port bird seems plausible as a DAYLG on virtually every count. There are some very good features: stocky structure with large rounded head, heavy bright bill with stubby tip and large red gonydal spot, relatively dark bluish-grey mantle, bunched points on folded wing at rest and extensive black triangle on wing-tip.
With regard to the reservations noted by others:
a) DAYLG are quite close to graellsii in overall length but have a heavier structure so they look distinctly larger in the field than graellsii. This bird seems to be quite solid structurally at rest compared to graellsii.
b) The bluish appearance is frequently found in DAYLG.
c) Legs of DAYLG are usually a gleaming ochre (earthy-yellow) in the breeding season but some individuals seem to be retarded or off-colour and remain with a non-breeding appearance. This might apply particularly to birds outside their normal range.
d) A minority (25%) of DAYLG do not show a solid black band on P5. In these less well-marked birds sometimes the break is just at the shaft but some have only a spot or even virtually no marking at all.
e) It seems unlikely to be michahellis (Mediterranean Yellow-legged Gull) because of the lack of a broad black band on P5 and the bunching of the white tips on the folded wing.
My one reservation concerns the photos and the determination of mantle colour. Is the bird really as dark as it looks on the photos? What comparisons were made with other nearby gulls? I'm also having difficulty, because of the lack of comparison, in determining the leg length. Are they really long as claimed?
Some relevant photos showing an April DAYLG on Fuerteventura, Canaries with dull legs and March DAYLG in Portugal with very little black on P5 and with typical structure (as 2nd summer) may be
found at:
http://www.nrossiter.supanet.com/ylg/index.htm
This site also shows two Portuguese DAYLG with thick and thin black bands on P5 and a pair of DAYLG in southern Morocco with just-visible bunched primary tips on the folded wing. It also contains a brief summary of the main features of DAYLG.
Dick Newell (Dick.Newell@Smallworld.co.uk):
Nice one Robert - if I saw this gull on my local dump, I would probably call
it argentatus, probably female, and pass on. I assume you will have checked
the fine detail of the primary pattern against Garner, Johnsson etc (I
haven't). Argentatus can be any shade of grey, they are not all dark. The
wing pattern of your bird is normally associated with more northern birds.
The state of wing moult is exactly the same as Herring Gulls (including
argentatus) that have been here (in Cambridge UK) during the last couple of
weeks. The build of your bird looks good for argentatus also. We all know
that hybrids can look like anything between the 2 parent species but I don't
see anything Glaucous structurally in your bird - that does not necessarily
eliminate the possibility.
I don't think there's anything wrong with the leg and bill colour for argentatus (they come in almost all colours - including yellow and pale pink legs). Was the shape of the bird at all different from the accompanying smithsonianus? If there was Glaucous in it, I would expect it to look dumpier - it looks dead right to me for argentatus. Did you get the eye colour, argentatus can be anything from yellow, through orange to red - I can't remember what smithsonianus is supposed to have. I doubt whether an albinistic smithsonianus would be quite that symmetrical. By the way, if it is argentatus, then I would call it female because of size (males are usually enormous) and the head doesn't look quite ferocious enough for a male, apart from which females migrate further than males see: http://www.gla.ac.uk/~gbza22/scand1.html.
Harry J. Lehto (hlehto@DENEB.ASTRO.UTU.FI):
Bob,
Quite interesting pictures you have. Would I have this kind of a bird
at "my" dump site here in SW Finland, I could easily pass it off as a
local Herring Gull. The ones we have here are Finnish herring Gulls,
considered to be L. a. argentatus, but apparently somewhat different from
the Norwegian argentatus population . All references below are to
"our" birds.
The long white tongue on P10 is quite OK for L. a. argentatus. The exact mantle color is difficult to judge from these photographs. The moult is more of less OK. The shape of the bird appears about OK.
Base of the bill, and leg color seems dull for an adult argentatus bird, and I think this is the field mark that might catch my attention would I see this bird here.
About the hybrid theory. I don't really see any clear indications of hydridism in this bird. Could this be a female L. a. smithsonianus? That could account for slimmer (bill) proportions and rounder head.
You will see from the photos that the wings are in molt [moult]. P9 is not visible, but I think all the others are. Apparently P5 has no black subterminal mark at all and P6 has only a spot. P10 is worn.
Regarding the primary patterns. I have looked in detail (both in field, hand and photographs) primary patterns of several hundred of our L. a. argentatus. Most have 6 black primaries. 5 black primaries are not very uncommon (as is your bird). 7 black primaries are findable on a daily basis. I have encountered only one ad herring gull here Finland with 8 black primaries (bird in hand) -- I reckon these occur in less than 1 in 1000 of adult plumages. On the other extreme, "Herring Gulls" with 4, 3, 2, 0 black primaries all have had either very peculiar patterns, paler "black" patterns and other characteristics suggesting hybridism or albinism, but I'll not go into this detail.
My question to the group is how much does the primary pattern of adult Herring (smithsonianus) Gulls vary? Is the variation as wide as in our argentatus? How much is the variation between the primary pattern of East and West coast birds? How about the birds in New Foundland?
Rik Winters (gagel@wxs.nl):
Here in the Netherlands, I'd call this bird an argenatus Herring Gull and not take a second look, but I don't have any experience with smithsonianus. I'd call it an argentatus and not an argenteus because of the general shape of the head and bill, the general appearance and the colour of the upperparts, which seem to be a little darker and more blueish and because of the weak gonydeal angle, which is not shown by all argentatus, but seemingly never by argenteus.
Note: my views are from a European perspective, having no experience at all with American Large White-Headed Gulls (I wish I had..).
Laurent Raty (l_raty@HOTMAIL.COM):
With birds molting primaries, it is frequent that the global appearance of the wing becomes weird. Feathers that are usually hidden become apparent when others are missing... In such cases, the first thing to do (though not always possible) is to look at each feather's pattern, individually, and to compare this pattern with what it should look like. When I look at your bird, I see:
* The outermost primary, p10 is extensively blackish (dark brown, in
fact, but the feather is old and faded - when fresh, color was
almost certainly black), with a (fairly large) terminal white
mirror. I don't think this mirror is too large for a _smithsonianus_
- although it is on the largest end.
On "Oct983.JPG", there seems to be a very thin subterminal black
marking on the right-wing p10, that might be indicative that the
mirror has not always been terminal.
All in all, this pattern may fit a _smithsonianus_ very well.
* p10 is followed by a very small feather, best visible from the
underwing on your "Oct988.JPG". This feather is extensively black,
with a white apical spot. You say only p9 is not visible, so let's
call this growing feather 'p9'.
However, I already have a problem : this feather, for what I can
see, does not show any hint of a mirror. For a gull whith much
white in the primaries, I would have expected a large amount of
white on p9 too...
* The following feather, call it 'p8', is not fully grown either,
being clearly shorter than 'p7'. On this feather's outer web,
black runs up to about half of the feather length. The black
pattern forms a broad band that crosses completely the feather
near its tip. There is a slight whitish tonge between the
adult-gray base of the feather and the black band, not very
obvious on "Oct988.JPG" but more visible on "Oct981.JPG", which
is quite unusual on a Herring Gull p8... (would be normal only on
a Slaty-backed.) The white apical spot is fairly large, but not more than expected
on a fresh feather.
(Editor's Comment: Raty is wrong here; such tongues are fairly common on smithsonianus and L. a. argentatus.)
* The next feather, say 'p7', shows a white apical spot, about the
same size as the one on 'p8'. This spot is followed by a quite
broad black band, itself followed by a thin, but well defined
white tonge. The black pattern on this feather is almost
restricted to the bar - there is very little black running along
the outer web.
* The next feather, that you call 'p6', has only a black spot on its
outer web, near its white apical spot, a quite unusual pattern for
a _smithsonianus_ p6. I would have expected a complete black band.
* 'p5' has no black at all. I'm not sure this is very rare on
_smithsonianus_, but it's certainly not the most usual pattern (it
occurs quite regularly on both _argentatus_ and _argenteus_, though
more often on the former).
We can also note that :
* Except on the worn p10, the black markings are clearly *jet black*
(not gray), from above and from below.
* Size is similar to _smithsonianus_.
* Mantle color is similar to _smithsonianus_.
* You describe the bill as slighter but, to me, it does not look too
slight on the picture for a female _smithsonianus_.
* There is a large amount of pink in the bill color (mainly visible
near its base on its right side, and near its tip on its left side)
and there is a slight blackish mark near the gonys on the right side
(these *may* indicate immaturity, i.e. 4th winter) - not sure if
this might by significant, but I have noted this pink coloration a
number of times on otherwise adult-like _smithsonianus_, while I
do not recall to have remarked it on _argentatus_ or _argenteus_ -
any thought ?
Now, look at it a bit more thoroughly: what is unusual in your bird?
* There are black marks on 5 primaries, while the normal number
would be 6.
* 'p5' has no black - this would be normal only for a p4.
* 'p6' has only a black spot, while it should show a black band -
but a black spot would be normal on a p5.
* 'p7' has a quite broad black band, but we would expect black to go
farther along its outer web - but this pattern would perfectly fit
a normal p6.
* 'p8' shows a white tonge that we would not expect on this feather
- but it would be normal on a p7.
* 'p9' has no visible white mirror, despite the large amount of
white on p10 tip - but, of course, a p8 never shows a mirror...
[But I think] there is one more feather missing... 'p5' is p4, 'p6' is p5, 'p7' is p6, 'p8' is p7 and 'p9' is p8. The real p9 has just been lost and is not yet grown at all.
I think you numbered the feathers on the basis of "Oct981.JPG". In this case, your 'innermost primary', visible on this picture is in fact an outermost secondary. Look carefuly at this feather, you will notice that its shape is slightly different from the shape of the following feathers (slightly less pointed and more symmetric). Look at the length of your 'p7' in the open wing, on "Oct988.JPG" or "Oct986.JPG". This feather *is fully grown* - its alignement on 'p6', 'p5', 'p4'... is perfect. Now, look at the feather's tip position on the folded wing - on "Oct989.JPG" for example. It is the shortest feather to be shown beyond the tertials. If you take any picture of adult Herring Gull in fresh plumage, you will see *4* white spots on a folded wing. As these do not involve p10, these are the tips of p9, p8, p7 and... p6.
I am especially interested to hear from those familiar with L. argentatus argentatus as to the liklihood of the bird being that form.
Discussion:
I thank Laurent Raty for his especially thorough discussion, and I like his idea that P9 is totally absent and so the primary with the small black dot is P5. That makes the primary visible on Oct9811.JPG [#11 on the web page] and Oct988.JPG [#8] as just growing in to be P8, not P9. That explains why no mirror is visible on that feather, as Raty says. I (and others) originally thought that from Oct9812.JPG [#12] and Oct985.JPG [#7] you could see that it is P6 that has the small black dot near the tip. It doesn't quite show on the slide scan, but on the original slide of Oct985.JPG the black dot is just barely beyond the cropping at the right edge. So the rightmost primary on Oct985.JPG is either P6 (my original thought) or P5 (Raty). If Raty is correct, then what appears to be the first primary tip is slightly rounder than the next because it is a seconadry. On the other hand, the size of its white tip is small, like a primary, not a secondary. The photos of Herring Gulls in Grant show that P1 has a rounder shape than P2, and show that the size of the white tip is a good way to separate secondaries from primaries.But overall I accept Raty's numbering of the primaries. Actually, that doesn't change the strength of the argument that the bird is a female L. a. argentatus at all! With Raty's numbering, the bird is very similar to plate C1, right birds labeled "6", in Lars Jonsson's article "Yellow-legged Gulls and Yellow-legged Herring Gulls in the Baltic", Alula 3 (1998): p. 80. The small white tongues match, as does the amount of gray on the inner web of P10. The bird here seems to be between the two in Jonsson's sketch. It is also very similar to the photo on figure 11, p. 83. However, it also might possibly be just a smithsonianus.
In balance, I think the bird's primaries are beyond the extremes of smithsonianus, at least for any that I have ever encountered. I think the white end to P10 is too large for smithsonianus. There seems to be ample reason to think that it is L. a. argentatus. Mantle color is fine. Of course, that's not proof. It is too bad that the bird was not seen a month later, after primary growth was complete! As usual, the real value comes in studying and comparing photos and sketches on these odd cases.
The Possible Argenteus in Connecticut
Bruce Mactavish (bruce.mactavish1@nf.sympatico.ca):
This bird looks good for argenteus. The bill is short, almost stubby. This is a feature that frequently strikes me on photo of argenteus and on birds I've seen in England and Ireland. Smithsonianus usually have a long, more drawn out bill. The pink base to the bill is slightly troublesome. All of the photos I have of 1st winter argenteus (about 30 individuals) show blackish bills, some with pale pink coming through in patches in the basal half of the bill, none as extensively pale as the Connecticut bird. However my collection of photos is not extensive. The bill colour may be OK for argenteus.
The small rounded head is good. Overall the bird seems smaller than a normal female smithsonianus.
The head and upper neck is whiter then Newfoundland smithsonianus. In December Newfoundland smithsonianus are mainly dark headed. The lower body appears to be a solid brown wash. Argenteus usually have a coarse, marbled brown pattern to the body with less of a sharp contrast between a white head and neck. But this is probably within the limits of argenteus. The light brown tone of the underparts is different than the more chocolate brown of the average smithsonianus in Newfoundland.
The scapulars are all first winter feathers. This is good. Most smithsoniaus, in Newfoundland at least, retain some juvenile scapulars right through the winter. Argenteus are said to have replaced all the juvenile scapulars by November, according to Anthony McGeehan in Ireland. All the 1st winter argenteus photos I have from Ireland December to February show a full set of first winter scapulars.
The greater wing coverts are boldly checkered white and brown. Even the bases of the outer ones are checkered. This is good for argenteus. Argenteus can have muddy bases to the outer most greater coverts but smithsonianus usually have extensive dark muddy bases to most of the greater coverts. The overall impression of checkered median, and greater coverts is almost Great Black-backed Gull-like. Smithsonianus are usually have more brown than white in the coverts with an overall impression of mottlely brown.
The tertials are deeply notched near the ends with shallow pale notches around the fringe. Some smithsonianus in Newfoundland are like this but the majority have pale markings confined near the ends of the tertial feathers with a narrow pale fringe along sides. I think there is much overlap in the tertials of argenteus and smithsonianus.
The tail band is perfect for argenteus and is well beyond any extreme smithsonianus that I have encountered. Even the central tail feathers have pale bases. 'Extreme' Newfoundland smithsonianus can have pale markings at the bases of the three outer most rectrices with the outer web of the outer most feather being marked with white on the basal two thirds. Most first winter Newfoundland Herring Gulls show only a trace of pale markings at the very base of the outer most feather.
The upper tails coverts are whitish with thick brown bars. The area in white is larger than the area in brown. This is good for argenteus. Smithsonianus have more heavily barred upper tail coverts often with a less contrast with the tail band and back. The zebra barred under tail coverts are also good for argenteus. Smithsonianus have heavily barred undertail coverts, pale bars narrower and overall less contrast.
This gull looks very good for argenteus. When I say argenteus I am lumping it with argentatus. Birders in Britain identify argenteus and argentatus, mainly the adults. The differences in first winter argenteus and argentatus are more subtle. One identification feature that may turn out to be useful is the scapulars. Last winter Anthony McGeehan in Northern Ireland noted that all 30 first winter argentatus in late January had some juvenile scapulars. Since first winter argenteus should have not have any juv. scaps after November this could be a good mark. However more field testing needs to be done on this feature.
In St. John's, Newfoundland we see one or two argenteus/argentatus per winter (none yet this season). Several are photographed. Two first winters are close enough to see scapular details. One in mid November had all juvenile scapulars and one in late January had many juvenile scapulars. The verdict is still out by they may be argentatus not argenteus based on this. Over the years I have identified three adult argentatus in NF (two well photographed). These were obvious birds - big, dark mantled, restricted black and large white windows in wing tip. So argentatus can get to this this of the Atlantic. Many European Herring Gulls may not be identifiable to race. The Dutch have lumped argenteus and argentatus as one species. (yes species, different from smithsonianus!). There may be more interbreeding of argenteus and argentatus in the Netherlands blending the already subtle differences therefore making subspecific identification nearly impossible.
Julian Hough (Jrhough1@AOL.COM):
It may be of interest to include the following observations from a recent trip to the UK during late November.
Typically, argenteus in late November look very white-headed and white-chested with the upperparts noticeably barred (since the upperparts are all moulted to first-winter by this date unlike many 'smithsonianus'). At a distance, this recalls, for use of a better analogy, the barred pattern shown by juvenile Long-tailed Skua, a pattern I don't typically see in 'smithsonianus'. The wing-coverts generally tend to be paler, more chequered (due to narrower dark bars), the bases of the secondaries tend to be evenly barred, not darkening as on many 'smithsonianus', and the tertials have larger, more extensive 'notches'. While this is variable, those argenteus with extensively pale tertial tips do not seem to be matched by 'smithsonianus'.
The colour of the flanks on smithsonianus is often rather dark and dusky, forming a noticeable patch - even on 'pale' birds. In dark birds it may not stand out due to it beingconcolourous with the rest of the underparts. Argenteus tend to be paler here, more uniform in colour though I am sure that this feature, like many others, is too variable to use alone.
Overall, there is much overlap in the features, particularly the tail pattern and rump colour. Some 'smithsonianus' lack obvious dark bases to the greater coverts and can be so variable in plumage that they do not conform to the current literature 'image' of this race.
How does this relate with our CT bird? Firstly, I think a lot of the plumage features of this bird fit argenteus. The tailband, stocky bill, moult pattern of the upperparts and general feather detail seem good. The long wings and the amount of pale on the bill are somewhat contradictory, since I wouldn't expect argenteus at this age to show this much pale by late November.
The question that arises is, that if such features are within the range of smithsonianus, then it looks like proving European race Herring Gulls is an uphill struggle here in the east, particularly since the tail pattern, the single-most reliable feature used to identify smithsonianus (in Europe at least), may be the variable wrench in the works.
Dick Newell (Dick.Newell@Smallworld.co.uk):
Let me comment, bearing in mind that I don't know much about variability of smithsonianus at the "vanilla" end of the "chocolate/vanilla" spectrum of these things. I doubt whether either of these gulls would draw much attention on my local dump here in Cambridge UK, where we have a lot of argenteus and argentatus Herring Gulls.
British argenteus are not normally migratory, nor are Icelandic ones according to BWP, they just "disperse". BWP implies the same about southern Scandinavian Herring Gulls, but northern ones, particularly females are migratory (see http://www.gla.ac.uk/~gbza22/scand1.html). So I would be surprised if both of these birds were argenteus. The most likely form that I would expect you to get would be female argentatus.
The first bird has quite a long primary extension, and also a somewhat pinkish base to the bill, it is also quite pale. If it had any more pale fringes to the primaries, I would plump for argentatus - I don't think you can eliminate it easily.
The second bird looks more the shape of argentatus than argenteus to me - quite long primary extension and the longer head and longer bill gives me that impression (but it's not a slam dunk).
A small proportion of 1st W (presumed) argentatus gulls are very pale, almost look like Glaucous hybrids, with heavily patterned tertials and broad white fringes to all of the primaries - often with a pink base to the bill, but black cutting edge. They are usually long in the head, bill and wing projection. I have always assumed that these come from the extreme north and are not like your birds at all. But argenteus/argentatus is a cline, and I have no idea where the line is drawn.
Question: what was the underside of the outer primaries like? - some 1st W argentatus are very white (especially presumed northern ones) - sometimes hard to tell from a white-winged gull from below, I don't think argenteus can look like this. Rather like 1st winter Thayer's Gull, which looks like a pale Herring Gull from above, and Iceland Gull from below.
So, in conclusion, your birds may be argenteus but I would favour argentatus and presumably you know why they are not smithsonianus (presumably that tail-band). One thing is clear to me, I don't look at my Herring Gulls critically enough to answer your questions more definitively - new year resolution: "I will take photos of Herring Gulls this year".
Harry J. Lehto:
Laridists, I am giving here a couple of comments to Bob Lewis's comments to my earlier posting.References are made to Lars Jonsson, "Birds of Europe," page 278, 280. Delin and Svensson, "Birds of Britain and Europe," p. 133.
Harry J. Lehto wrote: "the barring at the base of the tail looks odd as does the weakish contrast between the uppertail coverts area and the mantle." Then Bob Lewis wrote: "Jonsson p. 280 shows little contrast between the uppertail coverts area and the mantle, and shows a tail extremely similar to this bird's."
These drawings are for some reason not accurate (may be they are earlier Jonsson production). They are good enough for separating L. fuscus, marinus and argentatus from each other, but all these first winter/juvenile gulls have a rump/utc area depicted too dark. These pictures have other inaccuracies too and they are not up to Jonsson's more recent standards (such as shown in many passerines and some other gull plates).
Bob Lewis wrote: "Delin and Svensson, page 133, lower right photo shows a bird with P9 > P10."
Let's start from the 2nd winter bird (p. 133K). It shows nicely the "double tip". The picture on p. 133L seems to show a Herring Gull with P9 < P10. But there are two explanations to this. If you look carefully at the figures on page 133, you may notice that the picture 133J is claimed to be a juvenile. The mantle feathers look to me like 1st winter, the same is also suggested by the paleness at the base of the bill, so it seems that there are errors in this book too. The picture 133L, which Bob referred to shows an all dark (or at least much darker) bill than 133J, may be it is the juvenile one? (and the age part of the label has been mixed up). In which case P 10 could still be growing. From the published photograph I cannot assess the age more accurately.
The second explanation, which is more relevant here is more of a cautionary note. Birds that appear to show P10 < P9 in flight (open wing), may still have P10 extending to or beyond P9 when perching (closed wing). This argument is based on personal photographs of Herring Gulls showing the same individual in flight and on ground. I'm not convinced that 133L shows P9 smaller than P10.
According to the photographers' list 133L was taken by Prof. R. J. Chandler, so I'm guessing that it is a British argenteus, and 133J by Urban Olsson (which could imply Swedish origin).
Diederik Kok (d.s.kok@chem.uu.nl):
I prefer talking about AHG and EHG instead of smithsonianus, argenteus and argentatus. Clearly, this gull shows many, already discussed characters which fit better on EHG than on AHG. There are, however, also some features which look strange to me for an EHG. The bird gives a rather pale overall impression, but the belly and flanks of the bird are relatively dark brownish. The result is that the upperparts appear paler than the underparts. I find this a strange combination for an EHG. Also, the brownish flanks and belly are rather uniform. In a first-winter EHG (especially one with scapulars, head and wings as pale as on this gull) I would expect underparts that are not only paler but also, and more importantly, much less uniform.
Many EHG show quite dense barring on the tailfeathers just above the tail-band. This fits photo 222 in Grant. Dense dark barring as extensive as on the CT gull and over the whole length of the feather is, however, in my opinion much less common.
Grant photo 221 seems to show a mostly flesh colored bill, but I think this is merely a light artifact. A two-coloured bill as that of the CT gull is really exceptional, though not impossible, for an EHG by late November / December. It could be possible that there is some geagraphical variation in bill patterns of first-winter EHG, but I do not think it will be large and I have never heard of populations of EHG which develop two-coloured bill early.
Rik Winters (the second bird):
As I reacted to the first bird, I more or less feel obliged to comment on the second too. The more so as I think this bird is OK for European Herring Gull (EHG) (meaning argentatus + argenteus, but I guess you got used to that already). In short: everything seems to be OK on this bird, although it's not 'typical' in all respects, but it's well within the variation as I know it.More in detail:
Structurally the bird is OK. It looks not very big and it's relatively rounded in it's overall appearance, which is most common among argenteus types. The bill is allright. it's rather slender and thickest at the weak gonys. The tip is black and the basal two-thirds are darkish (only visibly lighter than the tip within reasonable distance). The legs are the good length and colour: dull pinkish. The state of moult is good, with all the juvenile scaps replaced and the head whitening. The amount, type and colour of streaks on head and neck is quite typical. The underparts are maybe a bit too evenly coloured -a more patchy appearance is the default-, but it's not too dark and the colour is OK too. The wing is good, albeit that the coverts are on the light side of the variation, but well within limits. The greater coverts showing parallel alternating dark and light bands is typical for individuals as light as this one. The tertials are good (seem to be a little bit abraded), the dark centre typically brown with a buffish white edge along the whole (visible) feather with marked triangular notches. The folded primairies dark brown, with a very small light edge to the tip is perfect. The length of the primairies projecting beyond the tail is good, maybe a little bit on the long side of the variation, but this could be a photographic effect. The undertail coverts are OK. The tail pattern is not good judgeable, but what can be seen is fine. The underwing is good as far as can be judged.
Alltogether this looks like a quite normal EHG to me, the type of bird I look at at almost daily basis. If I would encounter this individual there would be very little that would attract my attention. As I mentioned before, the underparts seem a little bit too evenly coloured and the scaps are a little bit untidy: usually at this time of year they form a quite regularly patterned unit more or less contrasting with the (juvenile) wingcoverts, this can be striking at times.
The set of features shown by this bird rule out every other European gull, and are all OK for EHG. Although I don't know the American and Eastern Russian/Asian Gulls that well, I wouldn't hesitate to call this bird EHG anywhere on the planet, because I think this bird falls within the part of variation of EHG that's the least troublesome: when they become bigger and/or darker, then there's a chance of confusion, but not on this type of bird (as far as I know).
Norman van Swelm:
I've looked thouroughly at this bird and I can think of no reason why it should not be a first winter argenteus. As soon as I can I will check the bill colours or rather the development of colour changes in our birds for certainties sake. Nevertheless I am surprised given the persistent W and SW winds here since September that this birds turned up in the US. Congratulations to the photographer.
Later:
Dear Bob,
Thanks for your message. Well the 2nd bird too looks perfect for argenteus! For a better insight in the American situation I
recommend commencing a colour-ring project in the US and Canadian colonies such as we have here. It will reveal many
interesting information.
Later:
Dear Bob,
Thanks for your message. I also read Dick Newell's letter. Herring Gulls can fly considerable distances. Dutch argenteus can make
easily 300 kms per day on routine feeding flights. I would not bother too much about the pink [on the bill], it is not very much and some
young argenteus here show already a little bit pink in September. As for the discussion on birdwg01, it does not change my opinion a bit. I am however very cautious on variation within smithonianus.
The 3 new photos did not change my mind, if anything it is argenteus.
Discussion:
Bird One: This is tough and tantalizing. Except for the pink bill coloration, I would not hesitate to call it an argenteus. The tail is completely beyond anything I have ever encountered in smithsonianus. I just can't believe that is the tail of a smithsonianus. Also, the uniform barred markings on the greater coverts are beyond anything I have seen on smithsonianus. It is very interesting to compare photos 107 and 131 in "Identification of Yellow-legged Gulls in Britian," by Garner, Quinn, and Glover (British Birds Sept. 1997). These are photos of argenteus Herring Gulls.
Actually, concerning the statements above that the bill color is too pale for argenteus, look at photo Q on this web page. (I added this photo to the page on February 6, 1999.) This is a shot that I took in mid to late July 1994 in Holland. I was not especially interested in Herring Gulls on that trip, and took only six or so photos of juvenile Herrings. Yet here is a bird with a lot of pale coloration on both mandibles! It is very easy to imagine that in three months its bill would be a duplicate of the Connecticut bird's. This is direct confirmation (should any be needed!) of Norman van Swelm's comments above.
Might the bird be Herring X Ring-billed? The bird does have a slender Ring-billed look. But has such a hybrid ever been recorded?
Bird Two: If only we had a clear shot of the tail! Sure seems to be an argenteus! And this one doesn't look at all like a hybrid with Ring-billed.
The Possible First Year Yellow-legged Gull in CT
Gerd Rotzoll and Detlef Gruber (Rotzoll@mbox.iftc.uni-hannover.de):
Dear Patrick Comins,I have looked at the images of the mystery gull together with Detlef Gruber yesterday. We came to the conclusion that the gull is one from the "yellow-legged" group. This is mainly based on the tail pattern. L. (c.) cachinnans can be safely ruled out because of the wrong head/bill shape and the underwing being too dark.
Contrary to my earlier opinion Detlef thinks that the clearly visible primary "window" could be within the variation found in L. (c.) michahellis. But he also thinks that it could be a bird from the closely related atlantis taxon (which breeds on the canaries etc. and thus is closest to america). To differentiate between these two better photos would be necessary in order to see more feather details.
The Possible L. a. argentatus in Connecticut
Martin Garner:
Comments as follows on your interesting 1st winter gull as follows. Clearly an interesting individual, esp in N. American context, and very well photographed. The only area of plumage I have difficulty 'reading ' is whether the scapular feathers are a juv-Glaucous-like pattern or a 1st winter argenteus-type pattern...or a mix?? However it doesn't really affect my other comments, though might be instructive to note carefully in the field. I agree that the bird does not immediatly recall the Nelson's Gull (smithsonianus X hyperboreus type hybrid), though neither does it appear to me to be a juv/1st winter argentatus. Inevitably there is a slightly hypothetical angle to these comments as I have never been to breeding grounds of northern - most argentatus or where hyperboreus type hybrids occur. That understood, your bird has too much of a glaucous type bill in both shape and colour...a little longer ,thinner and slightly more droopy on northern argentatus, and only becoming pale flesh, basally later in the winter. The head shape, chunky and rather squarish, is completely wrong for argentatus, again more Glaucous-like. Overall the plumage tones too are too pale for most northern argentatus in my experience, which actually tend to be rather dark and meally...many northern argentatus in 1st winter are actually good impersonators of smithsonianus in plumage tones...which may be a surprise to some. The body shape too is too compact, not so flat-backed and attenuated as argentatus. Finally many argentatus retain many/most juv scaps which are extensively dark centred well into feb/march. Thus, I do not think your bird is 1st winter northern argentatus. In Ireland where we regularily get a bizarre collection or weird and wonderful apparent hybrid Glaucous types your gull would fit well into the range of these. So possibly it is a Nelson's Gull, in a new variant (or even 2nd gen hybrid??) , or the other possibilty , which would in theory explain its unfamiliarity, an argenteus X hyperboreus hybrid ... presumably from Iceland.
Norman Van Swelm:
Hello Patrick, Thanks for the fine set of photos. Very interesting. The flight shots could have been taken in Holland and the same is true for the single wing shown. In the sitting bird the wing and tertial are pale but the pattern occurs in Holland and is not rare. It is the head that confuses me. I forgot the date when you took the photo's but only a few Dutch L.a.argenteus have obtained a pale bill as your bird has by the beginning of December. The possible hybrids I saw last weekend still had for the most part a dark bill, yet they looked much more a hyperboreus than your bird. I don't know how the bill colour of hyperboreus juveniles develops, here these birds are seldom seen sooner than January and by then they have fully developed coloured bills. Similarly I don't know how quickly smithonianus gets its bicolored bill. But it is the over all headshape in your bird and its comparatively small eye that makes me think that there is a hyperboreus influence. It is a big bird is it not? If I had to guess I'd say that this is a hybrid from Iceland.
since February 4, 1999
