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 partial moult, October 03 2002, Etaples, France. 

The following feathers are included in the partial moult: tertials #1-#2 (tt1, tt2) are new, the lower tertials are still old second generation. In the greater coverts, #2 (gc2) has been replaced and #5 is missing. In the median coverts #1-#2 (mc1, mc2) have been replaced, #4 is missing, #6 has been replaced and all feathers from #8 outwards are new. The inner lower lesser coverts (illc) #1, #4-#7 are new third generation, #8-9 are old second generation, #10 is missing. In the upper lesser coverts (lc) only one innermost feather has been renewed. The exact age of the scapulars is very to ascertain, as scapulars are moulted 'continuous' as it seems, although at a lower pace in winter. By May, 2CY michahellis may show already 95% third generation scapulars and a vast majority is moulting again in June and (still?) in August. Some scapulars may thus apply to third generation feathers but likewise apply to fourth (maybe fifth) generation scapulars. In the picture, the abraded lower scapulars with brown centres (ls) are probably old third generation feathers, the fresh plain grey feathers in the lower upper scapulars are probably fourth generation. In the mantle (m), similar grey feathers are growing in.