Gull Research Organisation

Gulls in NW Europe

(last update: September 25, 2011 )

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argentatus / argenteus

graellsii / intermedius

michahellis

marinus

Herring gull 2cy-10cy (argenteus) NLA 5.352.764 IJmuiden, the Netherlands.

Ringed at IJmuiden as pullus, early in the season on May 31 2002 at IJmuiden (52.28N 04.35E). Male.

below: 2cy, January 19 2003 , IJmuiden, the Netherlands (52.27N-04.33E).

This is an example of typical Dutch argenteus by mid-January: a bird ringed Arnhem 5.352.764 and it shows the average moult score. The mantle and upper scapulars have been replaced and the smudgy grey centres have already turned pale buffish; now contrasting with the brown anchor or barred pattern. The white fringes on the older feathers are worn away. Last moulted feathers can be found in the lowest row of lower scapulars. Base colour of these feathers is buffish-grey and they do not contrast as obviously as the older feathers. In many cases, a few lowest scapulars are still juvenile. In this individual, the juvenile rear lowest scapulars are clearly visible: all-brown with strong abrasion in the fringe.
The head and breast have been moulted for second generation as well, but all other feathers are still juvenile. Commonly, the juvenile tertials, the inner greater and the inner median coverts show much wear. The white notches along the fringes wear away easily by a lack of pigmentation (which makes dark feather parts stronger) and the smooth feather edge may turn in a 'stamp-edge', the brown pigmented parts remain and protrude, including the central shaft. The outer coverts look much better conserved with a neat edge, the outermost greater coverts protected by the flank feathers and the feathers of the side-breast.
The juvenile primaries are clearly pointed, unlike the rounded remiges shown by so-called "second winter" birds. The iris remains brown-black as in juvenile plumage, but in quite some birds the bill already turns paler at the basal half by mid-January.