© P. Stewart

This adult or near-adult Yellow-legged Gull was trapped at Throckmorton Landfill as long ago as 1990. Note the relatively dark shade of grey of the upperwing, with a strongly contrasting white trailing edge. Pattern of primary tips with more extensive black than in argentatus Herring Gull and closer to argenteus. Black on six primaries and a complete black band on p5.  'Classic' michahellis are white-headed in winter but by no means all individuals are classic. Fine head-streaking (but not spots or blotches) are quite regular in the immediate post-moult period, September - November, and may persist later into the winter on some individuals (and is normal on the form 'lusitanius' from western Iberia). The dusky marks in the tail and wing-coverts may result from discolouring to a considerable extent but conceivably this individual is 'sub-adult'.