The outer primaries are still visible and are clearly old juvenile primaries. In some 2cy Mediterranean Gulls, the outer lesser coverts at the carpal edge are still juvenile, but are adult-like in this bird.

From May to September, a complete moult takes place, into so-called "second winter" plumage. The head pattern will resemble the pattern in first winter birds, with blackish mask behind the eye from September onwards. But still, the head is dark with white flecking in this bird. The mantle, scapulars, tertials and all the wing-coverts are replaced for plain pearl-grey feathers. The secondaries are completely white. The second generation primaries are much paler than the first juvenile primaries, but still not nearly all-white as in adults. Note the old brown juvenile outer primaries, still present in this individual. In 2cy autumn Mediterranean Gull, the wing-tip pattern will be diagnostic with black on P5-P10: P5 has only a small black sub-terminal spot, becoming gradually larger on the outer primaries as the black patch "eats up" along the edge of the outer-web, most prominent on P10. In some birds, the outer greater primary coverts may show dark markings as well. The bill is orangey-red with a dark sub-terminal band. The legs are dull red or more obvious orangey-red.