Herring
Gull - Zilvermeeuw (argentatus & argenteus)
(last update: 28 maart 2005)
Home
Links
to Gull Sites
Gull Taxa
Gull Topography
Grey & Colour Charts
Locations in NW Europe
Summaries of Articles
About ORG
@
Herring Gull x246862 adult (argentatus), October 21 2004, Westkapelle, the Netherlands (51.33N 03.25E). Picture Pim Wolf.
This adult is metal-ringed Denmark ?246862. The primary moult score: P8 fully grown, no old primaries left. This adult argentatus has obvious black markings on the bill.
From June (often mid-May in France, Belgium and the Netherlands) to October, a complete moult will bring birds in so-called "adult winter" plumage. A new set of primaries will grow during the summer months and by October, all the old primaries are shed in argenteus in the Netherlands and northern France. In adults, the new primaries are visible beneath the tertials. At the same time, the wing-covert moult is completed by the end of the month. In summer, the head is still largely white, but by September, most adults develop extensive 'winter streaking', in sub-adults strongly mottled brown contrasting with the white breast as in an executioner's hood. The scapular coverts are plain grey, lacking white crescents. The tertials show obvious white tips. The iris is yellow. The bill is yellow with a red gonydeal spot confined to the lower mandible. The orbital ring is yellow-orange in most argenteus.
