www.gull-research.org

This month we saw incredible flocks of Herring Gulls from Scandinavia at the beaches, with groups of several 1,000's together in compact groups at small areas. After some stormy days, large colonies of American jack knife clam (Ensis americanus) became available as food resources and this early Xmas feast was well appreciated.
http://www.gull-research.org/hg/HG5CY01.htm repeats the table on 200 wingtip patterns from various Norwegian locations that was published by Barth in 1968. Many birds from far northern origin have only limited black in the wingtip. Interestingly, birds with black on only 5 primaries, may still show a very limited mirror on P9 and a full sub-terminal band on P10. But most eye-catching birds are those with thayeri patterns on P9 and P10, simply beauties!

Hi Mars,
did this second bird have dark grey mantle ? Looks quite pale in the photographs ?

Hi Peter,
In all respects it remembered me of typical northern argentatus, both in structure as in upperpart grey tone. It was a dark grey, stormy, clouded afternoon, and Photoshop adjusted the colours of my dark original images into what you see here...

Again some nice northern bird. Several of these large buggers are really on the dark end of argentatus, but they do not necessarily show less black in the wing-tip. Dark birds with incomplete bands on P5 are also present.
On the other hand, birds with a grey tone just a shade darker than local argenteus, may show reduced black, like a clean P5-tip, and a broken P6 band. Here some pictures again, to me they are among the most beautiful we find at the beach now at Noordwijk, Netherlands (my local patch nowadays).
Mars