Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 20-2-2007)

Herring Gull 3cy (argentatus?), May 16 2002, Boulogne/Mer, France (50.42N,1.34E).

This is most probably a 3cy argentatus. As can be expected in argentatus, the scapulars still show many abraded brown feathers with only very few plain grey feathers. The bill is turning slightly yellowish at the centre and a first hint of a red gonydeal spot is visible, though the bill is still very immature. The two upper tertials are more densely patterned than the lowest tertials, lacking a greyish centre. It's hard to tell if those feathers were moulted in the partial autumn moult to third generation feathers, as all the tertials and wing-coverts are worn by May. 
The tail shows a broad dark band. The primaries show the common pattern for 3cy: no white tips (although a slightly paler crescent is visible) and no mirror on P10. The bill is still immature, dark blackish at the tip and dull yellowish at the base. 
In argenteus, the scapulars create a grey saddle. It strongly contrasts with the brown-white chequered wing-coverts and dark centred tertials.