An adult argenteus ringed in the Netherlands: Arnhem Ringstation 5.36?.103.

The bill has no black markings. The orbital ring is yellow-orange. The legs are whitish flesh coloured.

In the primaries, note the reduced black sub-terminal band on P10, restricted to two small black spots on the  edge of the outer-web and the edge of the inner-web. The white tip of P10 is connected with the mirror by a broad white bridge at the centre. The black patch between the apical spot and the white inner-web (the medial band) is very broad along the edge of the inner-web. Argenteus normally shows such a broad medial band, where it is restricted in argentatus.

Already by the second week of February, at least 25% of adult argenteus from the Netherlands are in active moult on the head. This is often obvious in the feathers around the eye, which are shed by the second week of February, leaving a naked ring around the eye (visible at close range). Last years (2000-2003) winters have been very mild, with many adult argenteus back in the colonies by early February in the Netherlands (north to 53° latitude).