Strange white?-winged gulls in Essex

Following on from this thread relating to the gull we saw in essex this weekend: http://www.birdforum.net/showthread.php?t=162793
Here are various unusual gulls from Essex. Image one: presumed 2nd win Glaucxherring, Image two: 1st winter glaucxherring, Image three: same bird as image two, Image four: very pale argentatus or glaucxherring and Image five (photo by Steve Arlow): multi options- 'leucistic' herring gull/hypothetical herringxiceland/multi generation herring/glauc etc.