2cy Lesser Black-backed Gull L fuscus

Lesser Black-backed Gull - Larus fuscus intermedius

1-2: © Ruud Altenburg, 20-06-10. Kruisbergstrand, Heemskerk, Netherlands.

Occasionally it is extremely difficult to judge the primaries, which is essential for identification of 2cy fuscus. In plates 1-2, in dull weather, the primaries look blackish, rounded and only slightly worn, indicating they could very well be second generation feathers. Combined with the plumage, which is typical for 2cy fuscus, the identification seems a cinch.

Lesser Black-backed Gull - Larus fuscus intermedius

3-5: © Ruud Altenburg, 21-06-10. Stille Strand, Castricum, Netherlands.

The same bird was relocated the next day in much better light conditions. However, even in better conditions, only plate 5 unequivocally reveals that the visible primaries actually are dark brown, contrasting clearly with the black in the second generation rectrices. This can only mean one thing: these feathers are still juvenile. No matter what light conditions, the pale shaft in P10 is visible in all pictures; this is a clear hint that at least the outer primary is not a second generation feather. The fact that this individual shows juvenile primaries does not necessarily exclude it from being a 2cy fuscus, yet it obviously does not match our criteria for acceptance.