(4 images) Larus fuscus fuscus 2cy, July 09-13 2003, Tampere, Finland (61.33N 24.59E).
A 2cy fuscus in Finland in July. Moult timing is similar to some 2cy intermedius or 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 primaries P1-P4 are fully grown, P5 is growing and P7-P10 are still juvenile. All tail-feathers are fresh second generation.
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.
The complete wing-covert panel has been replaced on the wintering ground, now second generation feathers, lacking any pattern of transversal bars or anchors. The lesser coverts show a diffuse dark triangular centre, typically for second generation feathers in fuscus. After arrival in Scandinavia, this bird again started moult in the coverts. In the right wing, the upper tertial is growing and the second tertial is missing. The second greater covert is growing as well, and new plain blackish coverts are visible in the lower lesser covert row.
The bare part coloration is still most immature with a dark iris, pink-based bill and yellowish pink legs.New feathers grow in in the lower upper scapulars and in the rear lowest scapulars; 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. The scapular moult doesn't follow the ordinary sequence and these scapulars are probably third generation.
The complete wing-covert panel has been replaced on the wintering ground, to second generation feathers, lacking any pattern of transversal bars or anchors. After arrival in Scandinavia, this bird again started moult in the coverts. New plain blackish brown coverts are visible in the median coverts and central lower lesser coverts. They clearly contrast with the old abraded second generation wing-coverts.
The bare part coloration is still most immature with a dark iris, pale-based bill and yellowish pink legs.
It much resembles some intermedius LBBG, seen in NW Europe in June & July, see those sections.
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.