Larus Sp id, maybe caspian (9 pics inc.)

[michael23]

Hi everyone, i was at staunton harold resevoir in leicestershire today and whilst looking through the gulls i picked this one out. I have only ever seen a 1st winter caspian, and not got anywhere near the experience i would like with other plumages. I'm pretty shore though this one is a Caspian, but obviously i need your help with this one! It came across as a very "smart" looking gull, beautiful clean white head, not a mark on it. Totally different to any other herring and yellow legged types I have seen.
Also there was a black band/mark on both upper and lower mandibles.
I appologise for the quality of the pics, these were digiscoped and handheld at a high magnification (32x or 50x eyepiece plus fuji f40) Looking forward to the answer for this one

So hear are the pics...

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull002.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull003.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull004.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull005.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull012.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull030.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull031.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull035.jpg

http://i692.photobucket.com/albums/vv283/michael23_photo/Larus%20Sp/posscaspiangull036.jpg

[DLVelasco]

Hi,
The bird is a Yellow-legged Gull and not a Caspian for several reasons: quite dark grey upperparts, short legs, wrong head shape and bill shape for caspian, lack of dark feathers on the hindneck and, above all, typical YLg primary pattern (broken white mirror on tip of P10, undersurface of p10 with usual michaellis pattern and lack of white "fingers" on the upper surface of mid primaries)

hope this helps

Daniel L. Velasco

[michael23]

Hi,
The bird is a Yellow-legged Gull and not a Caspian for several reasons: quite dark grey upperparts, short legs, wrong head shape and bill shape for caspian, lack of dark feathers on the hindneck and, above all, typical YLg primary pattern (broken white mirror on tip of P10, undersurface of p10 with usual michaellis pattern and lack of white "fingers" on the upper surface of mid primaries)

hope this helps

Daniel L. Velasco

Hi Daniel, many thanks indeed for your input, it certainly does help.:smile:

Should there not be head streaking at this time of year? Also the black band on the upper and lower mandibles I dont recall seeing on yellow legged before?

[Brian S]

Hi Michael

I can only agree with Daniel on this one. I can understand why you thought it might be cachinnans, but the subtleties all point to michahellis.

Good try...

Brian S

[michael23]

Many thanks Brian, :smile::beer:

[DLVelasco]

Hi Michael,
Though most YLGs, specially lusitanicus, show some head streaking at this time of the year, it´s not rare to see adults with completely white heads in winter.
Regarding bill colouration, winter adults (both young, intermediate and old adults) usually (not always) have at least some black on the lower or upper mandible, near the gonys

Dani

[JanJ]

Hi Michael,
Though most YLGs, specially lusitanicus, show some head streaking at this time of the year, it´s not rare to see adults with completely white heads in winter.
Regarding bill colouration, winter adults (both young, intermediate and old adults) usually (not always) have at least some black on the lower or upper mandible, near the gonys

Dani


Variation shown here:

http://www.gull-research.org/ylgadsubad/adnov/06cynov.htm

JanJ

[michael23]

Hi Michael,
Though most YLGs, specially lusitanicus, show some head streaking at this time of the year, it´s not rare to see adults with completely white heads in winter.
Regarding bill colouration, winter adults (both young, intermediate and old adults) usually (not always) have at least some black on the lower or upper mandible, near the gonys

Dani
Thanks again Daniel.

Variation shown here:

http://www.gull-research.org/ylgadsubad/adnov/06cynov.htm

JanJ

Thanks for the link Jan.

[MichaelF]

Variation shown here:

http://www.gull-research.org/ylgadsubad/adnov/06cynov.htm

JanJ

From the site:
"Yellow-legged Gull ... is a common migrant from July to December in NW Europe"
Just to clarify, that really ought to read "common ... in parts of NW Europe". YLG is still a description rarity in northern England (less than annual in e.g. Northumbs) and nearly a 'mega' in Scotland; I don't suppose they occur at all often in Iceland, Norway, etc., either.

[John Bell]

Hi Michael et al,

I don't think Yellow-legged Gull is anywhere near a mega in Scotland. There are a few most years at least. I think Norway has had a few but they are rare there as you say. i don't know about Iceland.

cheers,
John






From the site:
"Yellow-legged Gull ... is a common migrant from July to December in NW Europe"
Just to clarify, that really ought to read "common ... in parts of NW Europe". YLG is still a description rarity in northern England (less than annual in e.g. Northumbs) and nearly a 'mega' in Scotland; I don't suppose they occur at all often in Iceland, Norway, etc., either.

[Giroud Marc]

Concerning YLG in Iceland : http://www3.hi.is/~yannk/status_larcac.html

Marc