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 02 2003, Amsterdam, the Netherlands (52.23N,04.54E).

2CY michahellis which has moulted the head, neck, breast, flanks and belly to second generation. In the left wing, tertial #1 has been moulted to second generation. Furthermore, in the left wing, greater coverts #2, median coverts #10-11, lower lesser coverts #4-6 and #12 and two lesser coverts are second generation as well, with the last moulted feathers showing a different pattern and a greyish base. The other wing-coverts are still juvenile. In the right wing, moult is less advanced, with all the tertials and all the greater coverts still juvenile. The left-wing moult stage in the median, lower lesser and lesser coverts is mirrored in the right wing.
The lowest row of lower scapulars are fresh second generation feathers with a grey base on the last replaced feathers. Seven lower upper scapulars have been replaced recently for third generation feathers. Those feathers show a black shaft and a grey base. In 2CY michahellis it's common to find birds continuing 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).
The head shows a dark patch around the eye which extends on the nape and a boldly streaked neck-collar. The bill is all dark. Note that so-called "first winter" michahellis doesn't necessarily have to show a peculiar obvious white head.
In the background, three Herring Gulls (all argenteus).