Herring Gull- Zilvermeeuw (argentatus & argenteus)
Herring Gull plumages:
hg sub-ad January
(2 images) Herring Gull HT-193833 3cy (argentatus), May 18 2004, Amsterdam, the Netherlands, (52.21N, 04.52E). Picture Ruud Altenburg.
3cy argentatus, ringed in Finland. As soon as ringing data are available, more information will be added. The complete moult has started as the inner primaries have been moulted recently. The fresh scapulars are plain grey, as is a single median covert. However, most coverts are still second generation-like.
From June to October, a complete moult
will bring 3cy argentatus in so-called "third winter"
plumage. By August, the first neat streaks can be found on the crown and
neck. After the complete moult is finished in autumn, the head will show
extensive 'winter streaking', often neat fine streaking in argentatus
and mottled brown contrasting with the white breast as in an executioner's
hood in many argenteus. The scapulars and mantle are pale
adult-like grey, although some individuals may show an immature pale brown
hue or arrow-head patterns on the lower scapulars.
During the summer, the primaries are moulted to third generation. In argenteus, the first inner primaries are dropped by late May and the outer primary P10 will be dropped by late August. The primary moult is completed by late-October, in argenteus, when the new outer primary P10 is fully grown. Preliminary data from Tampere, Finland, indicate 3cy argentatus from this region are not delayed in primary moult compared to argenteus from continental NW Europe. The third generation primaries are clearly adult-like, with inner primaries P1-P3 plain grey with a white tip. The outer-wing shows a clear black triangle, extending on the greater primary coverts. From P4 outwards, the primaries show black sub-terminal markings. The white primary tips are obvious in the inner primaries, but are only poor developed on third generation P9 and P10. The third generation P10 normally shows a small white mirror (lacking in some birds). The new tail-feathers will be predominantly white, with clear immature black markings. The iris turns pale yellow in summer in most argenteus (July-August), but quite some argentatus will keep the iris amber to dark brown.