Caspian Gulls L. cachinnans

An adult looking bird with grey feathers on three inner tertials, the inner greater coverts, (almost) all median coverts and some lesser coverts. The latter are mostly 2nd generation (obtained during its first winter), making this bird a 2nd winter.

This beautiful slender bird is probably a female. Note its striking slender bill (compared to the bird in the above picture) and its pure white head and underparts. It still has most of its 2nd generation wingcoverts, with a few 3rd generation median coverts.

Almost all birds of this ageclass have a white mirror on the outermost primary (P10). In e.g. Herring Gull and Yellow-Legged Gull this seems more rarely to be the case.

A more adult looking bird, which resembles the one in the top picture. Note the long neck and bill, the shawl of narrow grey streaks in the hindneck and the mirror in P10.

This bird could easily be confused with a 1st winter. The mantlefeathers, however, are 2nd (the marked ones) and 3rd generation (pure grey). Note the darkish bill.

Andreas Buchheim

Eichenstrasse 1, 45711 Datteln, Germany