Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 9-2-2007)

Herring Gull 5.352.714 3cy (argenteus), March 17 2003, Le Portel / Boulogne-sur-Mer, France (50.42N,1.34E).

A 3cy argenteus, ringed in the Netherlands, Ringstation Arnhem 5.352.714. It was ringed as pullus on July 02 2001 at IJmuiden, the Netherlands (52.28N 04.35E). This individual represents the typical Dutch 3cy argenteus having the scapulars plain adult-like grey, contrasting with the barred lesser coverts, creating a saddle effect. In this individual, almost all scapulars are plain grey, except some rear lower scapulars. It also shows the typically pinkish base to the bill and a broad bill-band. The second generation primaries have small white crescents and lack 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, but this Dutch bird obviously show moulted tertials and wing-coverts, replaced in the partial autumn moult as 2cy bird: tertials #1-3 have been replaced, greater coverts #1-3 have been replaced and some inner median and lower lesser coverts have been replaced (for anchor patterned or barred 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.