nominate Lesser Black-backed Gull (L. f. fuscus)

(last update: 10-11-2009)

Larus fuscus fuscus 3cy CT-128.000, July 12 2003, Tampere, Finland (61.33N 24.59E).

Larus fuscus fuscus in 2cy often returns with completely replaced primaries and secondaries. In 3cy, fuscus more often shows a clear division between fresh inner primaries and older outer primaries, the inner primaries often showing neat white tips and the outer primaries often second generation-like with rounded tips and paler bleached brown. The arrested moult in the primaries is often reflected in the secondaries and (to a less extend) in the tail-feathers as well. The older tail-feathers (often R5 is older) still show a broad dark sub-terminal band.
3cy fuscus often have some black markings on the bill, which is otherwise much adult-like, with a clear red gonydeal spot. The colour of the naked parts are adult-like as well. 
The scapulars in 3cy are often completely adult-like, lacking internal patterns; plain blackish grey with a mahogany hue on the older feathers. Most wing-coverts and tertials are adult-like blackish grey as well, but often 3cy birds show some very bleached pale brown wing-coverts, normally in the greater covert bar and in the upper rows of the lesser coverts. These bleached wing-coverts accentuate the jumpy sequence in the last wing-covert moult cycles, as there is often no clear pattern in location of these bleached feathers. Head and body feathers normally are snow-white by July.

CT-128.000 was ringed in Finland, now in 3cy. This 3cy fuscus has arrested the primary moult prior to northbound migration: there is a clear division in the visible outer primaries between P8 and P9. The two outer primaries (P9-P10) are paler brown second generation. P10 has no mirror. The other visible outer primaries, P5-P8, are much darker with relatively large and fresh white tips (adult-like primaries) and are next generation flight feathers.
Note the black markings on the rectrices, limited dark markings on the bill and the retained bleached wing-coverts and lower tertials, typical for 3cy birds. CT-128.000 was photographed in rainy conditions.