This fascinating bird was seen several times on the tip during the day, initially fairly distantly and was mobile until it finally gave itself up to very close quarter views. When I first picked up on the bird I called Iceland Gull however the structure and dusky primaries lead me to believe it was probably a Kumlien's Gull. It was a large bird, about the size of a small Herring, thus larger than usual Iceland Gulls, and has a rather un-Iceland Gull like head and facial expression. During the day the bird had the appearance of Kumlien's when seen on the deck and I was in favour of this ID, albeit perhaps at the paler end of the spectrum.
Thoughts of a darker winged Iceland Gull were discussed however I have never come across any of these myself it was considered however again the structure didn't feel right for Iceland Gull. Rich Bonser was never really completely happy it was a Kumlien's given his greater experience of this 'form', due to his many trips to Ireland versus my paltry 8-10 birds of various ages.
It is also possibly a hybrid, given the size of the bird and the rather Herring Gull face however at the time of observation this was thought unlikely as there really wasn't any real obvious hybrid influence, I considered the Herring face to be perhaps a result of it being a large male Kumlien's. Rich thought it might be a hybrid.
So what is it?
1 - Iceland Gull which is dusky winged, large and with an un-Iceland Gull face (mean rather than gentle)
2 - Kumlien's Gull at the paler end of the range thus not resulting in typical dusky wing tips and a being a male accounting for the large size
3 - hybrid which would account for the facial impression, large size and dusky primaries.
If it is a hybrid clearly there would be 'Arctic Gull' influence given the overall Iceland Gull effect but what of the other parentage? Iceland x Herring Gull, Iceland x American Herring Gull, second generation hybrid. If a hybrid then it's a scary one for gullers.
Extended set of images to demonstrate the bird.
Hover over the image below to show the features that matches the Rainham bird