Yellow-legged Gull - Larus michahellis

(last update: October 08 2013)

Delfín González
Gabriel Martín
Antonio Gutierrez
Amir Ben Dov
Mars Muusse

Yellow-legged Gull michahellis 2CY, February 09 2003, Etaples / Boulogne-sur-Mer, France (50.42N,01.34E).

Typical 2CY michahellis which has replaced the head, neck, breast, belly and flanks to second generation in the first pre-basic moult last autumn. It also included some wing-coverts and the upper tertials in this moult. In the left wing all tertials are still juvenile, but in the right wing tertials #1-2 have been replaced. Greater coverts #1-3, #5, #11, median coverts #1-9, lower lesser coverts #1-3, #5-7 and about 17 lesser coverts are second generation as well, with the last moulted feathers showing broad fringes (e.g. surprisingly the inner greater coverts). The other wing-coverts, the tail feathers and tertials are still juvenile.
The rear feathers in the lowest row of scapulars are fresh second generation feathers with an anchor pattern, a buffish base and neat tips. At least two upper scapulars have been replaced recently for greyish third generation feather, but the exact extend of this replacement is hard to judge when the feathers are wet. In 2CY michahellis it's common to find birds starting to replace upper scapulars to third generation feathers, while the rear lowest scapulars have only very recently been replaced for second generation feathers. By this stage, this individual shows first generation feathers (remiges, rectrices, most wing-coverts), second generation feathers (the head, body, most scapulars and some wing-coverts) and at the same time third generation feathers (a few lower upper scapulars).
Note that the head and neck are by no way pure white, with dark streaking concentrated around the eye and extending on the nape. In the hind-neck streaks are bolder and create a neck-collar. The dark bill starts to turn paler at the base by February.