Possible European Herring Gull

There has been a very informative discussion of late on European/Vega Herring Gulls on ID Frontiers so I was a bit stunned when I spotted this bird literally at my feet today at the SSM Landfill. It immediately stood out to me as the best (and only) candidate for a European Herring Gull - Larus argentatus argentatus I had ever seen. After reviewing every available reference and picture in print and on the net I am still thinking that this seems to meet all the criteria for European Herring Gull.

For those not obsessed with Larus taxonomy. The three Herring Gulls- European, Vega and American are still even after a recent review considered subspecies of  Larus argentatus - argentatus, vegae, smithsonianus respectively by the AOU. The BOU and virtually everyone else including Olsen & Larrson consider them distinct species. Seperation European and American Herring Gulls can be most difficult but in some cases may be possible especially in first year birds.

So here is my candidate for Larus a. argentatus

Possible First Winter European Herring Gull

 So clearly this is a first winter bird and has molted its juvenile mantle and scapular feathers. First notice how pale this bird is overall with a white ground color and a frosty appearance. The coverts are spotted and the tertials heavily notched.

Possible First Winter European Herring Gull-Close Up

The mantle and scapulars are pale and lightly barred. The notching of the tertials is well demonstrated

The coverts and mantle in this bird appear to be nearly identical to the L.a argetatus illustarted in Olsen & Larsson pg. 269 #331. Lets move on to the tailband.

Possible First Winter European Herring Gull -Tail Band

This bird has a broad blackish tailband with barred bases of the outer tail feathers with white tips. The upper tail coverts have a white ground cover. This is probably one of the best features for distinguishing between American and European Herring Gull. Below are several pictures showing the typical American Herring Gull tail. All black with heavily marked rump and coverts.

First Winter American Herring Gulls- Tail Pattern

Here are a few more pictures showing the sparsley barred undertail coverts and a comparison with a typical American Herring Gull.

Comment: Tony Leukering noted " I was curious as to the photo date of the second picture of smithsonianus depicting typical tail patterns.  It's bill pattern suggests a bird older than a 1st-cycle, though the primaries might be pointed enough to be juvenal feathers.  The mantle also seems to show some older-type feathers, but I cannot be sure from the picture."


The picture was from Nov. 9th/2007. Looking at the whitish rump and bicolor bill plus the mantle I think this is likely a second cycle bird. Thats what you get for doing the blog at 0300.
Kirk

Possible First Winter European Herring Gull- Undertail Covert

Juvenile American Herring Gull - Undertail Coverts

On to the wings. The European Herring Gull is supposed to differ from the American in the absence of dark tips on the inner webs of the inner primaries (P1-3)with two-toned outer primaries.

Possible First Winter European Herring Gull - Wing with Close Up

Well P 1-2 are certainly devoid of dark markings on the inner web tips and P3 has some pale gray markings. Here is an American Herring Gulls for comparison.

First winter American Herring Gull - Wing Close Up

Here the tips of the inner webs of the inner primaries clearly are darkly pigmented and the pattern noticeably different from the candidate European Herring Gull.

Below are a few more pictures the first showing showing the underwing.

Possible First Winter European Herring Gull

The only thing I could find weighing against this being a European Herring Gull was a comment in Howell and Dunn that this taxa does not typically show a flesh pink bill with a clean-cut black tip which my candidate bird does. Olsen & Larsson don't specifically mention this point. In the superb article by Lonergan & Mullarney entitled Identification of American Herring Gull in a western European context they state:

"Bill-colour There is a tendency for both smithsonianus and argentatus to develop a pale bill base quite early in the first winter, with the most extreme birds approaching first-year Glaucous Gull in this respect. In argenteus the contrast in the bill pattern tends to be subdued until late winter".

 This article is available on the net at the following link:

http://www.irbc.ie/notes/pdf/IdentificationOfAmericanHerring(Mullarney&Lonergan).pdf

It would seem according to this expert opinion that the bicolor bill is not an issue for L. a. argentatus.

In conclusion I feel this bird is a very good candidate for a first winter European Herring Gull. I have spent 100s of hours over the last several years studying 1000s of first winter American Herring Gulls and though the variation is truely remarkable I think this bird may well be out of range.

I would very much appreciate any opinions especially from those with experience with this difficult diagnosis.

Kirk