Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 5-11-2006)


Herring Gull plumages:

hg 1cy July
hg 1cy August
hg 1cy September
hg 1cy October
hg 1cy November
hg 1cy December

hg 2cy January
hg 2cy February
hg 2cy March
hg 2cy April
hg 2cy May
hg 2cy June
hg 2cy July
hg 2cy August
hg 2cy September
hg 2cy October
hg 2cy November
hg 2cy December

hg 3cy January
hg 3cy February
hg 3cy March
hg 3cy April
hg 3cy May
hg 3cy June
hg 3cy July
hg 3cy August
hg 3cy September
hg 3cy October
hg 3cy November
hg 3cy December

hg sub-ad January
hg sub-ad February
hg sub-ad March
hg sub-ad April
hg sub-ad May
hg sub-ad June
hg sub-ad July
hg sub-ad August
hg sub-ad September
hg sub-ad October
hg sub-ad November
hg sub-ad December

hg ad January
hg ad February
hg ad March
hg ad April
hg ad May
hg ad June
hg ad July
hg ad August
hg ad September
hg ad October
hg ad November
hg ad December

Herring Gull 5.412.502(argenteus), October 2003 - February 2004, IJmuiden, the Netherlands (52.27, 04.33E). 

Ringed as fledged 1cy in the Netherlands: ringed Vogeltrekstation Arnhem Holland 5.412.502. It was ringed on September 09 2003 at IJmuiden (52.28N 04.35E) as weakened 1cy. It was held in captivity for more than 24 hours before it was released again at IJmuiden harbour. As is standard for 1cy argenteus, all the wing-coverts are still juvenile. All lower scapulars are still juvenile. One upper scapular has been moulted to second generation, two others are missing.
The partial autumn moult in argenteus (moult from juvenile plumage into so-called "first winter" plumage) includes the body and head feathers. This moult starts as soon as the nest is abandoned (late June) and continues until January. In general, the head turns paler on throat and forehead. The breast will turn paler as well. The feathers on belly and vent will still be juvenile in most 1cy argenteus by November. From July onwards, the mantle and upper scapulars are moulted to second generation feathers, showing an anchor pattern and a dark base. The lowest row of scapulars are still juvenile by March in most 2cy birds (contra e.g. michahellis). The notched pattern of the juvenile scapulars is repeated on the juvenile lesser, lower lesser and median coverts, although the medians have paler centres. The juvenile greater coverts show a 'piano-key' pattern; on the outer greater coverts as well. The tertials have an obvious notched pale fringe and transversal bar. 
The juvenile wing-coverts, rectrices and remiges start to bleach and show wear in the fringes from September onwards. The secondaries, primaries and primary coverts are dark with a small white tip, but the juvenile inner primaries show an obvious pale window, prominent from below and above. The under-wing is rather uniform grey-brown patterned. The tail has a broad sub-terminal band and isolated dark bars on the basal half. The iris is dark, the bill is blackish, sometimes with a paler base, and the legs are flesh-pink.

image below: 5.412.502 1cy, October 23 2003, IJmuiden. 

image below: 5.412.502 1cy, November 11 2003, IJmuiden. 

2 images below: 5.412.502 2cy, February 12 2004, IJmuiden. 

Between late October and February, the moult in the scapulars has become obvious. The second generation greyish feathers on the flank and in the neck also strongly contrast with the old bleached brown feathers on the belly. In the image below, in frontal view, the pattern of the post-juvenile moult in the under-parts is even more clear.

images below: 5.412.502 2cy, February 28 2004, IJmuiden.