Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 8-2-2007)

Herring Gull 3cy (argentatus), January 04 2002, Le Portel / Boulogne-sur-Mer, France (50.42N,1.34E).

A 3cy argentatus, which shows a delicate fine black pattern on a very pale base. The new third generation upper scapulars are not plain adult-like grey as in most argenteus, but the scapular region are moulted to third generation feathers which strongly resemble the second generation feathers. Consequently, 3cy argentatus may look very delayed in their moult, compared to argenteus in mixed groups and they can sometimes be mistaken for 2cy birds. Compared to argenteus, argentatus may show finer, more delicately black-patterned feathers, not as bold and smudgy as many argenteus show (especially in the second generation central greater coverts).
Note the primaries with rounded tips, clearly second generation feathers and unlike the pointed juvenile remiges. The extensive paler inner-webs of the inner primaries run down all the way to P7 and P8 (just visible in the folded wing). Argentatus may show a strong contrast between pale inner primaries and dark outer primaries and the 'window' created by these pale inner primaries is very obvious.

This individual has replaced many wing-coverts in the partial autumn moult as 2cy bird: the upper three tertials, the inner greater coverts, most of the visible median coverts and two inner lower lesser coverts have been replaced. The new feathers show a buffish hue on the pale parts and have fresh fringes and tips.