Candidate 2cy Heuglin's Gull L heuglini in W Europe

A very advanced 2cy bird, accepted as Heuglin's Gull for Germany.

A bird comparable to the individual above: very advanced with plain, pale grey feathers.

A bird showing a combination of characters that are very unusual for Lesser Black-backed Gull but also rather rare for Heuglin's Gull.

An individual resembling Caspian Gull.

A darker and more advanced bird.

A bird with a moult scheme found in Baltic Gull L f fuscus but the plumage is too pale for this taxon.

Comparable to the candidate above, but even more advanced: this bird already showed third generation primaries.

A pale and rather worn bird, several of which were observed in the Netherlands in 2006. It seems improbable that so many heuglini would occur in a single year so we assume these birds represent intermedius.

A presumed intermedius that has replaced the inner hand at the winter quarters.