Larus delawarensis
Moulting from first winter into second winter plumage
May - August 2006
Bergen, Hordaland, Norway

View a series of pictures showing the birds primary moult here.

Ring-billed Gull

Wing coverts and tail, 16 May 2006: Note the lesser coverts; broader centres than the arrowshapes in Mew Gulls. The tail is classical with dark smudging inside the terminal band. Note also a visible narrow white subterminal band. The bird has lost one primary at this date, and the dark tips on p2-p5 is unlike Mew Gull; diamondshaped and almost the same amount of dark on the inner and outer web. Compare this feature with a Mew Gull here.



Ring-billed Gull

Mantle shade, 28 May 2006: The second generation mantle and scapular feathers are slightly paler than on Mew Gulls. Note also the stouter bill with a small bright tip.



Ring-billed Gull

Underwing (bird on the left), 4 June 2006: It has a cleaner white underwing than Mew Gulls. Especially the centre of the underwing is almost pure white. At this date the bird had only five first generation primaries left.



Ring-billed Gull

New primaries and wing-coverts, 13 June 2006: The bird has moulted six primaries and we can see that p1 to p3 are soon to reach full length. Note the black tip on p4, and the beginning of p5. Almost all traces of first generation greater coverts are away, while new median coverts are growing. The tail feathers are still completely unmolted.



Ring-billed Gull

Ring-billed Gull

Moulting the tail, 25 June 2006: Only three primaries are left (as it was four days ago), but the new inner primaries and wing-coverts are steadily growing. Finally it has shed most of its tail-feathers, only the two outermost retrices on both sides are left (lower picture, bird to the left).



Ring-billed Gull

Outer primaries are all second generation, 26 July 2006: Most primaries and secondaries shed by now. The tail-feathers are growing, but the dark spots on the central feathers are visible (picture). Notice the dark bases to the tertials. The bill-tip has brightened a bit during the last 14 days, and the ring has become more pronounced than ever before.



Ring-billed Gull

Still growing flight-feathers, 7 August 2006: Both secondaries and primaries have steadily grown during the last ten days. The tail-feathers seems to be full grown by now. The remaining first-generation lesser coverts have almost disappeared completely.



Ring-billed Gull

16 August 2006: It is still around (exactly) three months after it was first found. All juvenile flight- and body-feathers are shed, and the outer primaries seem to be the only feathers that are not fully grown. The bill has aquired three distinct colors; yellow tip, black ring and a bluish base.



Ring-billed Gull

29 August 2006: The outer primaries (p9 and p10) are the only feathers that are not completely grown out yet.

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Posted 08.06.2006

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