Larus fuscus

A 2cy fuscus in Finland in July, called 'Ring-billed Hanky'; jizz suggests a male. Moult timing is similar to some 2cy heuglini but the very blackish brown fresh coverts and scapulars advocate nominate fuscus. Most of the flight-feathers are still juvenile. This individual did not include primary moult in the post-juvenile moult on the wintering ground. After arrival in Scandinavia, P1 was dropped and an ordinary moult sequence was started: the inner primary P1 is fully grown, P2 is growing and already slightly longer than P1, P3-P4 are missing, P5-P10 are still juvenile. All tail-feathers and secondaries are still juvenile and will probably be replaced when primary moult arrives at P6.
In the upper scapulars new feathers grow in; they appear dark blackish brown, lacking any obvious barring or patterns, except the hardly visible darker shaft-streak, just as the old bleached second generation scapulars.
Almost the complete wing-covert panel has been replaced on the wintering ground, now second generation feathers, most lacking any pattern of transversal bars or anchors. A few second generation lesser coverts show a club pattern, and the outermost lesser coverts in the carpal edge are still juvenile. After arrival in Scandinavia, this bird again started moult in the coverts. The second tertial is growing and in the wing-coverts, new plain blackish coverts are visible in the right wing's innermost two greater coverts, six median coverts, one inner and most of the outermost lower lesser and a few lesser coverts are missing.
The bare part coloration is still most immature with a dark iris, pink-based bill and yellowish pink legs.

Typical Finnish fuscus in July have replaced primaries, rectrices and secondaries, all moulted in a complete post-juvenile moult on the wintering grounds, prior to northbound migration. The new second generation primaries are only a couple of months old and still look dark blackish. The second generation tail-feathers normally still show the white tips, but in some individuals these tips are worn away when 2cy birds arrive back in Scandinavia. Immediately after returning in Scandinavia some 2cy fuscus start a new moult cycle in the inner primaries, now growing in third generation feathers.
The complete moult in the winter quarters normally start with replacement of the scapulars and mantle-feathers in November to January, but the post-juvenile moult may already start in juvenile birds which are still in Scandinavia in September. The new scapulars often show a simple pattern of a black shaft-streak on a dark brown base. When most of the scapulars are replaced, fuscus start to replace the wing-coverts, in the ordinary sequence that can also be found in other gull taxa in Europe. Wing-covert moult is initiated in two loci, one wave starts in the outermost coverts, one wave starts in the innermost coverts. The two waves normally meet at covert #7-8. Normally the median covert row is the first row which is moulted, followed by the lower lesser coverts, the greater coverts and moult finishes in the outer lesser coverts (the carpal edge). If for whatever reason, moult in the wing-coverts is arrested, this is normally most obvious in the carpal edge and outer greater coverts, containing juvenile feathers which contrast with the other fresh coverts.
In classical 2cy fuscus, all wing-coverts are replaced to second generation on the wintering grounds, and by mid July in Scandinavia, a next moult wave is initiated, often including the median and lower lesser coverts, the inner greater coverts, upper tertials and scapulars. Bare part coloration may be very immature, including a black bill, but may also be very mature, with a yellow base and a red gonydeal spot on the lower mandible. Still, these birds are only 12 months old.

July 09 2004

July 15 2004