Another gull ID challenge

[Yoav]

This interesting gull was photographed by a non-birder in the Bet She'an Valley, Israel on October 11th. At this time of the year armenicus is by far the commonest gull in Israel.

http://www.tapuz.co.il/tapuzforum/main/ShowImage.asp?path=//images/data/IMG2/Img/Forums/1_134528021.jpg&msgid=134528021

This seems to be a 2cy bird, but the yellow legs are pretty striking.

My first impression was of armenicus (small head, bill size and proportions) but this extremely long rear and heavy head markings are wrong for armenicus in this plumage. Head and neck streaking somewhat reminds argentatus group, but remember that aregentatus has been recorded only once in Israel. Shape and proportions almost remind of canus group. Unfortunately no images of open wing.

Your comments are welcome.

[MichaelF]

What about cachinnans?

[Yoav]

This gull shows several features contra cachinnans, including bill size and shape and strong head markings.

[MichaelF]

But the small-headed, flat-browed head shape, slender body and long wings appear (at least to me) to match cachinnans far better than argentatus. The argentatus that I see here in winter are hulking big brutes with heavy heads, not remotely canus-like in impression.

Does the lack of strong head markings in cachinnans invariably apply with 2nd/3rd winter birds like this?

[MichaelF]

Structure, including bill size, matches this one very well:
http://commons.wikimedia.org/wiki/File:Larus_cachinnans_3_%28Marek_Szczepanek%29.jpg

[JanJ]

The gull is certainly not a cachinnans (Caspian Gull) on features mentioned by Yoav and not a Herring either on structure. Although armenicus could be a good match I find it to boldly streaked on both head, neck, necksides and breastsides. Further, the grey tone seems a bit pale in the image for armenicus. What about a wellstreaked 2cy type michahellis?

JanJ

[MichaelF]

Isn't the bill too slender for michahellis?

[JanJ]

No Michael,
rather variable and also sex related - male has bigger bills.

http://www.xs4all.nl/~daarruud/micha/index.html

JanJ

[amir.bendov]

The Gull duscussed is not an easy one
i tend to agree that it is most likely a michahellis, though
1. the Yellow leggs showing 3rd CY caracters are very confusing
2. the bill is certenly problematic, not caracteristic for michahellis

they are quite rare at this time of year in Israel
it may be a mixture of the last X ?? (argentatus ? , cachinnans ?)

amir ben dov

[Brian S]

I would probably go with Armenian Gull. It is hard to explain why, just a gut-reaction based on my experience of michahellis.

It is hard to back this up with facts, as I agree it could possibly be a mich, but here is a bird labelled 'Armenian' that matches it in the streaking onto the body, which I can't really reconcile with mich - http://www.flickr.com/photos/rashed11112/2207586784/sizes/o/

Brian S

[JanJ]

I still think the heavy streaking on the head and breast sides are to heavy for armenicus. I also have some feeling of the bill being to long and somewhat slender for armenicus. However, is it a michahellis? I´m not at all sure of this gulls identity. I wonder what Mars would make of this gull?

JanJ