Gulls in NW Europe
(last update: September 25, 2011
Herring Gull 4cy GC-89668 (argenteus) April 2010 - August 2010, Leiden, the Netherlands. Pictures: Maarten van Kleinwee.
Bird ringed as 3cy in winter: March 07 2009 at Pitsea Landfill Site, Essex, United Kingdom.
below: 4cy GC-89668 (argenteus) August 14 2010, Leiden, the Netherlands.
Fourth-calendar year Herring Gull, moulting to winter plumage. Present now for the fourth month, the appearance of this gull is increasingly adult-like. Gone are the extensive black markings on the bill and the brown sub-adult tertials. However, with unfolded wing, this gull can still be safely aged by the brown outer primaries and primary coverts. Note the small mirror on the inner web of P10, the small black marking on the outer web of P5 and the missing greater coverts (thereby exposing the white base of the secondaries). P1 to P4 are new and fully grown, P5 is almost fully grown, P6 has been dropped.
Moulting score: 25 (P1=5, P2=5, P3=5, P4=5, P5=4, P6=1, P7=0, P8=0, P9=0, P10=0).
below: 4cy GC-89668 (argenteus) July 17 2010, Leiden, the Netherlands.
Fourth-calendar year Herring Gull moulting to fourth-winter plumage. The black markings on the bill are diminishing.
below: 4cy GC-89668 (argenteus) June 12 2010, Leiden, the Netherlands.
P1 and P2 have been shed. Also note the black subterminal bar on both the outer and inner web of P5, the dark primary coverts and the dark alula. Moult score: 2 (P1=1, P2=1, P3=0, P4=0, P5=0, P6=0, P7=0, P8=0, P9=0, P10=0). Note the yellow eye ring, the darkish iris and the dark markings on the bill. Compared to the first sighting, end of April, the brown tertials #1-3 have been shed.
below: 4cy GC-89668 (argenteus) May 08 2010, Leiden, the Netherlands.
Fourth-calendar year Herring Gull in summer plumage. Aged by the large amount of black on the bill, the light iris, the brown tertials #1-3, brown outer greater coverts and the completely white tail.
below: 4cy GC-89668 (argenteus) May 01 2010, Leiden, the Netherlands.
Fourth-calendar year Herring Gull in summer plumage. Note the all-white tail, the black bill markings, the brown outer greater coverts, primaries and primary coverts. Also note the dark markings on the alula and the primary coverts.
below: 4cy GC-89668 (argenteus) April 24 2010, Leiden, the Netherlands.
