Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Jean-Michel Sauvage (France)
Morten Helberg (Norway)
Nils Helge Lorentzen (Norway)
Mars Muusse (Netherlands)

Great Black-backed Gull (Larus marinus) 2cy: June 23 2003, IJmuiden, the Netherlands (52.27 N - 04.33 E).

An individual almost all wing-coverts moulted to second generation. Many lesser coverts are missing but some fresh second generation feathers are already visible. All median and lower lesser coverts have been replaced. The gap in the greater covert row has yet to be closed. As can be seen in the picture, two moult wave grow to the centre of the row. The outer greater coverts moult inwards, the inner coverts moult outwards and the two tracts meet at about covert #8. The upper three tertials are second generation as well, the fourth is growing and the juvenile lower tertials and innermost secondaries are just visible.

This bird is moulting the rectrices, with the outer two R5-R6 still juvenile and the central tail-feathers growing / missing. Primary moult stage: P8-P10 still juvenile, P5 at the length of the fully grown P4. Recently moulted upper scapulars have buffish centres and show the same (second generation like) pattern as the white based lower scapulars. The soft parts are very immature with the bill mostly black.