This juvenile Pallas'/Great Black-headed Gull (Ichthyaetus ichthyaetus) was photographed by Detlef Gruber
at Hannover, Germany in September. Detlef writes: "See the
pale greater upperwing coverts and broad pale fringes of all juvenile
feathers. In contrast Steppe Gull (cachinnans) shows dark greater
upperwing coverts and narrow fringes, whereas similar white eye
crecents can show both species":