Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 20-2-2007)

Herring Gull 5.365.545 3cy (argenteus), April 05 2003, Brouwersdam, the Netherlands (51.45N-03.52E).

This Dutch Herring Gull was ringed as pullus on July 01 2001 at Zoommeer, the Netherlands (51.30N 04.11E). 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, creating a contrasting "grey saddle" in many birds, as most of the wing-coverts (especially the lesser coverts) are still barred. The 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.

The image presents a typical argenteus, although still not showing the grey saddle. The brown second generation primaries are bleached and lack a mirror on P10. The second generation tail has a broad dark tail-band.
This individual has moulted some wing-coverts to third generation feathers in the partial autumn moult as a 2cy bird. By April, those third generation wing-coverts may be hard to recognize, as the patterns are very similar to the second generation feathers and the feathers are very worn by April.