Lesser Black-backed Gull L f graellsii
1: © Ruud Altenburg, 11-06-05; 2-4: © Ruud Altenburg, 10-06-05; 3: © Ronald van Dijk, 10-06-05. Amsterdam, Netherlands.
NLA 5.179.990, from Oost-Knollendam (52.30 N, 04.47 E), is a worn bird showing a white head and mostly white underparts. There are no juvenile feathers in the scapulars and mantle; they are either second generation and very abraded (the fringes are completely worn away) or fresh third generation (dark blackish-grey without obvious internal markings). The complete moult has started and the inner primaries have been shed; P1 is now growing again, P5-P10 are still old juvenile. In the mean time, replacement of the wing-coverts has started as well. Note the difference between the recently required wing-coverts, which show very neat tips and the wing-coverts replaced a few months ago on the wintering grounds. The outer greater coverts are still juvenile and are brown based and very worn. The tail is in active moult; this is unusually early as normally the tail-feather moult starts when primary moult arrives at P6 (P5 fully grown).