very dark 3rd cycle *herring gull* in cornwall

[lou bertalan]

hi,

on 26.11.2012 this very dark 3rd cycle herring gull type was photographed in cornwall.

http://www.birdforum.net/attachment.php ... 1354104455
http://www.birdforum.net/attachment.php ... 1354104413
http://www.birdforum.net/attachment.php ... 1354104437

checking peter's article about smith gulls in europe i didn't find any strong pointers towards american herring gull. so, can we definitely say this is a dark european teus/tatus or are the black secondary centers together with all dark rectrices a good pointer towards smith? i guess in all 3 taxa there are such well marked or retarded brown birds, so - is it possible to tell what this is?
posted by colin on birdforum: http://www.birdforum.net/showpost.php?p ... count=2524

lou

[adriaens]

Hi Lou,

birds like this are striking, of course, but identification of 3w smithsonianus is very tricky.
More detailed photographs are needed that allow close examination of the precise secondary and tail patterns.
Not sure if we can say much from these distant shots, but the outer secondaries look a bit brown perhaps,
and the black subterminal mark on P5 seems to have a rather blunt shape (at least on right wing)?
The mantle of the Cornish bird looks slightly darker grey than in typical smiths to my eyes, and the pattern on head and underparts
is not quite different from 3w argenteus.

This rather similar (but even more striking) 3w bird was present in the Netherlands last winter. It was widely twitched,
but in the end it was confirmed as a European Herring Gull when its DNA was examined.
http://waarneming.nl/foto/view/2941609
http://waarneming.nl/foto/view/2938932
http://waarneming.nl/foto/view/2938290
http://waarneming.nl/foto/view/2941607
http://waarneming.nl/foto/view/2938288