What's going on with that bill- soiled or aberrant?
Theres a dark spot of p7 and some markings on the primary coverts
Nice bit of light yesterday evening so went looking for the adult Glauc- seemed to have some strange marks, maybe soiling? Looks a bit thin necked and small headed too. More pics here: http://devilbirder.blogspot.co.uk/2014/02/a-rainy-days-gull-watching.html