© S. Nuttall

A juvenile Caspian Gull, photographed on the early date (for the West Midlands region) of August 22nd. Note the long, slender bill; the lack of a pale 'window' on the inner primaries; the simple pattern of the wing-coverts (lacking notches but with suggestion of pale 'wing-bars' at tips of median and greater coverts); the characteristic pattern of the tertials, with dark bases and neat, narrow pale margins confined to the tips; the pale underwing. The upperparts have rather narrower feathers than comparably-aged LBBG and HG, with a simpler pattern (lacking strong notches at margins and creating a more uniform, slightly paler (more 'muddy'), less strongly contrasted appearance overall). At this age the bill is usually predominantly dark and a strongly contrasted bi-coloured pattern, as here, is less usual. However, before mid-September, such a pale and strongly contrasted base is encountered more frequently in juvenile Caspian Gull than in Herring Gull  (Gibbins, Small & Sweeney, 2010). See images and captions of juvenile Herring Gull and juvenile Lesser Black-backed Gull for comparison.