Lesser Black-backed Gull (graellsii & intermedius)
(last update: May 17 2015)
LBBG 3cy, April 19 2003, Maasvlakte, the Netherlands.
In most 3cy LBBG, the moult strategy follows a standard sequence: mantle and scapulars form a grey saddle on the back when birds return in spring. Most April 3cy Lesser Black-backed Gulls still have most wing-coverts barred. Normally, the first coverts to be moulted are the median coverts.
This individual follows a complete different moult schedule and appears remarkable adult-like by April. Most upper-parts are replaced for plain grey feathers, the older feathers showing a brown hue and wear at the tips. The rectrices have been replaced for plain white adult-like tail-feathers, except the old R5, still showing a broad black band. A complete white tail is rare in 3cy LBBG, but occurs and can be found in spring in any large group of immatures. The primaries have been replaced as well at the wintering grounds, with the inner primaries moulted to fresh third generation feathers, showing small white tips in the primaries P6 and P7. The outermost primaries P8-P10 are still second generation, P10 lacking a mirror and the tips worn. Median coverts #1-3 are brown and have worn tips, tertial #1 is brown as well, with the tip completely gone.
Note the colour of the bare parts, with much black on the bill, almost completely obscuring the red spot, the speckled iris and the pale lemon yellow legs. The shade of grey on the upper-parts is not obvious different from local LBBG in the colony.