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, August 25 2000, Etaples / Boulogne-sur-Mer, NW France.

Another example showing the secondary moult stage nicely. By July, most of the secondaries have been shed (click the thumbnail for the secondary moult stage of July michahellis) but in the majority of the birds, a small block of juvenile secondaries remain at the inner half of the arm. Secondaries are moulted in descendant order, S1 is the first moulted feather (the outermost secondary) and in a wave, new secondaries grown inwards. The two or three innermost secondaries, often hidden by the tertials, are moulted simultaneously and finally the small block of juvenile secondaries is shed as well. Now, by the end of August, it's this group of secondaries which are renewed last in line and as can be seen in the left picture, the gap is closed from two directions.
As in many michahellis, p9 is almost fully grown and p10 is halfway it's final length. The complete tail has been replaced.