Ring-billed gull
Why aren't I a first-winter common gull?
Actually, many of these features, taken from Olsen & Larsson's 'Gulls of Europe, Asia and North America' are only pointers, and none alone is often diagnostic. Some first-winter common gulls are below for comparison, photographed at Chew Valley Lake on 30 December 2008. The Helston ring-billed gull is quite a gracile bird (perhaps a female) - however the worn tertials with only a little white edging, the patterns on the scapular feathers and the paler greater coverts stand out as plumage differences. In the water, the bird looked broader with a more flattened breast when viewed front-on, and the more robust bill had a clearly defined pale tip.
