I was really good to bump into Chris Townend and Russ Eynon this evening near the Imperial rugby ground. We spent the last half hour of daylight (plus a good deal of near darkness) trying to suss a white-winged gull roosting on Bull Hill. We zipped round to the docks for a better view of it but it remained frustratingly distant. Initial thoughts were that it had to be glaucous gull - a hefty bird clearly bigger than accompanying herring gulls. However it looked undeniably long-winged at times and there were moments when the larger size was not so obvious. To compound the difficulty we were mostly viewing it back-on when size can be deceptive. As far as age goes it was always difficult. A very white-looking individual with perhaps some pale grey in the mantle? The bill looked dull but we couldn't detect the classic 'pink dipped in black' of an immature so perhaps a third-winter or older? Difficult to say! It is probably best left as a probable glaucous gull. It never appeared small and dainty as the majority of icelands do and often looked really big but it was a bit of a chameleon to say the least. Hopefully it will reappear tomorrow.