A first calendar-year Mediterranean Gull moulting from juvenile into first-winter plumage. In second-winter and subsequent plumages, confusion is most likely between Mediterranean Gull and Black-headed Gull but in juvenile, first-winter and first-summer plumages Med Gull is superficially closest to same-age Common Gull. Note the following specific characters.

At rest:

• Relatively strongly contrasting 'piebald' plumage

• Dusky patch appearing behind eye

• New, very pale, 'pearly grey' feathers appearing in mantle

• Rather long, dark legs; bill also stocky and relatively dark but with somewhat paler base

In flight:

• Pale mid-wing panel created by pearly grey greater coverts

• Relatively clean, whitish underwing, with blackish inner border to primary coverts

• On the right wing note the dark leading edge to outer 'hand' but with whitish inner webs visible on well-splayed primaries (this is characteristic but when primaries are compressed the outer 'hand' appears all dark)

• Again, the dark legs and feet are conspicuous

At this age there is little likelihood of confusion with Black-headed Gull, especially in flight, but note also the structure and the pattern of the underside of the outerwing compared with the Black-headed Gull in the background, which shows slighter head and bill profile and characteristic white 'blaze' on the leading edge of the outermost primaries.

© A. R. Dean