Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: 24-12-2006)


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

(2 images) Herring Gull 5.365.172 2cy (argenteus), October-November 2002, Brouwersdam, the Netherlands (51.45N-03.52E).

This Dutch 2cy argenteus was ringed as pullus by Roland-Jan Buijs, at the industrial emplacement "Vlissingen-Oost / Quarleshaven" in the SW of the Netherlands on June 30 2001. From the first month after fledging, this bird was seen at Brouwersdam on several data.

From late April onwards, argenteus has a complete moult during summer to so-called "second winter" plumage. This complete moult will be finished by October and overlaps with the partial autumn moult which starts in September and often include scapulars, a few inner wing-coverts and upper tertials. The head has been moulted in July-August and shows neat fine streaking by October. The under-parts and rump are pale, mottled with brown. From mid-May, the scapulars and mantle were replaced for third generation feathers, starting with the replacement of the lower upper scapulars. The pattern of the third generation scapulars is more or less similar to the anchor pattern of the second generation feathers. By October, argenteus acquire some new adult-like pale grey scapulars. 

From early April, the inner primaries were shed and new second generation primaries grown in. On average, the last juvenile primary (P10) was shed in the first week of August. The majority of argenteus complete the primary moult by the first week of October, when the new second generation P10 will be fully grown. The new primaries are dark with a tiny pale tip on the fresh flight-feathers. The four inner primaries show an extensive pale window, as both inner and outer-web are pale greyish white-brown, contrasting with the outer-wing. A pale inner-web can still be found in P7.
The second generation tail-feathers show a clear-cut blackish tail-band with only isolated blackish markings on the white basal half.
By early October, argenteus finish the complete moult, with the central greater coverts and outer lesser coverts moulted last. Between September and November, the average 2cy argenteus start a simultaneous partial autumn moult in the wing-coverts, including the upper tertials, some median and lower lesser coverts and often the inner greater coverts.

This 2cy argenteus has P10 fully grown. All rectrices and secondaries are fully grown as well, replaced by second generation flight-feathers. This Dutch 2cy argenteus is illustrative for argenteus replacing wing-coverts in the partial moult: the two upper tertials, the two inner greater coverts, the second median covert (#2) are all replaced for third generation feathers recently. The new feathers are easily recognized by the warm grey-buff centres and the neat fringe.

image above: 5.365.172 2cy, October 19 2002, Brouwersdam, the Netherlands (51.45N-03.52E).

image below: 5.365.172 2cy, November 02 2002, Brouwersdam, the Netherlands (51.45N-03.52E).

The same individual, two weeks later. As can be seen in the image, the average final partial moult stage will be reached by October.