2cy Baltic Gull L f fuscus

Baltic Gull - Larus fuscus fuscus

1-5: © Ruud Altenburg, 20-06-04; 6-7: © Ruud Altenburg, 21-06-04. Amsterdam, Netherlands.

All scapulars, tertials and wing coverts have moulted to second generation feathers. In fact, several scapulars and lesser coverts are already of third generation and there is active moult in the tertials and coverts. The tail feathers have also been replaced, as have the secondaries, which show clear white tips in flight. The primaries have moulted to second generation feathers; only P9-10 are still brownish and therefore juvenile. In flight, it appeared that this bird had dropped P1 and thus had started moulting its primaries to third generation feathers. At this time of year, graellsii and intermedius are moulting their juvenile primaries to second generation feathers. The adult-like feathers look rather pale grey, but note that this impression changes when the birds is compared directly to a 2cy graellsii/intermedius in plate 4.

Baltic Gull - Larus fuscus fuscus

8-9: © Ruud Altenburg, 30-06-04; 10: © Ruud Altenburg, 01-07-04. Amsterdam, Netherlands.

After not having been seen for over a week, this bird returned to the same location, in the meantime having dropped P9. Notice the 'step' between the secondaries and primaries in the left wing, indicating that P1 is missing. This means the bird is simultaneously moulting the inner (to third generation) and outer (to second generation) primaries ("Staffelmauser"). This would be a very unlikely moult pattern for graellsii or intermedius.