Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 9-2-2007)

Herring Gull H-117858 3cy (argenteus), March 16 2003, Le Portel / Boulogne-sur-Mer, France (50.42N,1.34E).

A typical argenteus, ringed as pullus on July 20 2001 at Zeebrugge, Belgium (51.20N 03.11E), Bruxelles H-117858. Most of the scapulars are plain adult-like grey, contrasting with the barred lesser coverts, but still not creating a saddle effect. The bill is typical for 3cy birds in March, pinkish base and a broad bill-band. Note the rather brown second generation primaries lacking the mirror on P10. The tail is completely second generation, showing a broad band.
The moult-stage is sometimes difficult to interpret in 3cy argenteus by March. This Belgian individual has moulted a few tertials and wing-coverts in the partial autumn moult as 2cy bird: tertials #1-3 have been replaced, greater coverts #2-3 have been replaced, most of central median and lower lesser coverts have been replaced (for anchor patterned third generation feathers).

3cy argenteus has a partial moult in spring. It starts in January and is completed by April, leaving birds in so-called "second summer" plumage. The head turns white, especially on throat, breast and belly. By April, the scapulars and mantle will show many adult-like grey feathers, often creating a contrasting "grey saddle", as most of the wing-coverts (especially the lesser coverts) are still barred. The old second generation wing-coverts start to fade and the fringes wear off. 
The iris and base of the bill turn pale yellow, although some individuals show a warm amber iris. The bill shows some red on the gonydeal angle and it still shows an obvious dark bill-band.