Scandinavian Herring Gull Larus argentatus argentatus, White KH89, 3rd-calendar year.
Observed in IJmuiden, The Netherlands, October 15, 2011.
This subspecies can show much less black on the outer primaries, as is the case in this individual. Note how the black is restricted to the outer primary and trailing edge (L-shaped). Also note the ‘Thayeri pattern’ on P9, where the grey tongue joins the mirror (which incidentally is restricted to the inner web). Compare the pattern with the third-calendar year European Herring Gull (Larus argentatus argenteus) below.
Comparison: 3rd-calendar year European Herring Gull Larus argentatus argenteus:
Identification of American Herring Gull in a western European context
Authers: Lonergan, P, and Mullarney, K.
Publication: Dutch Birding 2004 – 26: 1-35
Contains information about Thayeri pattern in European Herring Gulls.
This individual as a 2nd-calendar year, France, February 2010