Herring Gull- Zilvermeeuw (argentatus & argenteus)
(last update: December 15, 2011
Herring Gull - 2cy May
Introduction
This website deals with the Herring Gulls of the taxa argentatus and argenteus. Argenteus is an abundant breeding species on Iceland, Britain, NW France, Belgium, the Netherlands and N Germany. The taxon argentatus breeds in NE Europe, from Denmark, the coast of the Baltic Sea, Scandinavia and coast of the White Sea. In the centre of the breeding range (Denmark and the NW German coast), birds show intermediate characteristics, indicating there is a cline in argenteus-argentatus. Argenteus in Western Europe is pale-backed, slightly smaller and with relatively much black in the wing-tip; argentatus in the NE Europe is larger, slightly darker on upper-parts and show less black in the wing-tip.
Due to the large breeding range, there is much intra-specific variation in argentatus, with most large, powerful birds in the northern populations, showing the most darkest upper-parts, longest wing and most white in the outer-wing. In this region, some populations may hold substantial number of yellow-legged argentatus. (referred to as "Finnmark yellow-legged argentatus"). In adult plumage, the black sub-terminal spot on P5 is often lacking or strongly reduced to a diffuse streak, broken at the centre. Sometimes P6 lacks black as well.
In the Baltic region, other yellow-legged argentatus populations occur ("Baltic yellow-legged argentatus"), with adults showing even brighter yellow legs in summer and the upper-parts only slightly darker than West European argenteus, still much paler than Yellow-legged Gull (michahellis). Those Baltic argentatus often show a black sub-terminal spot on P5 in adult plumage.
On these web-pages, we largely follow P.J. Grant: "Gulls, a guide to identification" and E.K Barth's publication as Contribution No. 86, Zoological Museum, University of Oslo: "The circumpolar systematics of Larus argentatus and Larus fuscus with special reference to the Norwegian populations".
2cy Herring Gull May: tables and charts
| Table 1: 2cy Herring Gull primary scores May 2001-2002 (n = 299). Remaining old primaries (e.g. 7 = P4-P10 old; P1-P3 active moult to 2nd generation). Surveys from Scheveningen harbour, except May 17, which is from Boulogne-sur-Mer, NW France. | ||||||||||||
| . | 20.04 | 22.04 | 27.04 | 03.05 | 04.05 | 08.05 | 11.05 | 15.05 | 17.05 | 26.05 | 28.05 | 03.06 |
| 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 3 |
| 5 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 2 | 2 | 3 | 11 |
| 6 | 0 | 0 | 0 | 2 | 1 | 0 | 3 | 3 | 27 | 6 | 12 | 16 |
| 7 | 0 | 0 | 2 | 3 | 0 | 1 | 5 | 15 | 36 | 3 | 15 | 3 |
| 8 | 2 | 3 | 5 | 17 | 5 | 12 | 7 | 23 | 8 | 3 | 4 | 4 |
| 9 | 11 | 7 | 8 | 19 | 2 | 19 | 1 | 6 | 2 | 0 | 0 | 0 |
| 10 | 42 | 34 | 37 | 13 | 3 | 9 | 1 | 3 | 0 | 0 | 0 | 0 |
n = |
55 | 44 | 52 | 54 | 11 | 41 | 18 | 50 | 75 | 14 | 36 | 37 |
| av old P's | 9,7 | 9,7 | 9,5 | 8,7 | 8,5 | 8,9 | 7,4 | 7,8 | 6,7 | 6,5 | 6,4 | 5,8 |
| 95% CID | 0,1 | 0,2 | 0,2 | 0,3 | 0,8 | 0,2 | 0,6 | 0,3 | 0,2 | 0,6 | 0,3 | 0,4 |
| SD (s) | 0,5 | 0,6 | 0,8 | 1,0 | 1,2 | 0,8 | 1,2 | 0,9 | 0,8 | 1,0 | 1,0 | 1,1 |
| % 's 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 6 | 8 |
| 5 | 0 | 0 | 0 | 0 | 0 | 0 | 5 | 0 | 3 | 14 | 8 | 30 |
| 6 | 0 | 0 | 0 | 4 | 9 | 0 | 17 | 6 | 36 | 43 | 33 | 43 |
| 7 | 0 | 0 | 4 | 6 | 0 | 2 | 28 | 30 | 48 | 21 | 42 | 8 |
| 8 | 4 | 7 | 10 | 31 | 45 | 29 | 39 | 46 | 11 | 21 | 11 | 11 |
| 9 | 20 | 16 | 15 | 35 | 18 | 46 | 6 | 12 | 3 | 0 | 0 | 0 |
| 10 | 76 | 77 | 71 | 24 | 27 | 22 | 6 | 6 | 0 | 0 | 0 | 0 |
Notes: CID: (Confidence Interval of the Difference); SD: Standard Deviation. |
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May Chart 1 (below): 2cy HG primary scores for May in 2002, except May 11 & 26 from 2001 (n = 299; late April, early June excluded). Data as in table 1. Chart 1 shows the early primary moult stage for 2cy Herring Gull; the complete spring - summer figure is plotted in chart 2.
The charts show the "Remaining Old Primaries".
rings argenteus: U.K.
Herring
Gull GR 15426 2cy (argenteus), May 31 - June 01 2012, Boulogne/Mer, France (50.42N,1.34E). Picture: J-M Sauvage.
Herring
Gull A5GR 2cy (argenteus), May 14 2008, Boulogne/Mer, France (50.42N,1.34E). Picture: J-M Sauvage.
Herring
Gull YR8.T 2cy-3cy (argenteus), May 2011 & October 2012, Boulogne/Mer, France . Picture: J-M Sauvage.
Herring
Gull DA-216323 2cy (argenteus), May 16 2002, Boulogne/Mer, France (50.42N, 1.34E).
Herring
Gull DA-216321 2cy (argenteus), May 16 2002, Boulogne/Mer, France (50.42N, 1.34E).
Herring
Gull H-117394 2cy (argenteus), May 16
2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull H-117661 2cy (argenteus), May 16 2002, Boulogne/Mer, France (50.42N, 1.34E).
Herring
Gull Y.ALM adult (argenteus), May 08 2010, Leiden, the Netherlands.
Herring
Gull 4284031 2cy (argentatus), May 02 2003, Boulogne/Mer, NW France.
Herring Gull VF5J (argentatus) 2011-2012, Finland. Pictures: Visa Rauste.
Herring
Gull KH89 2cy (argentatus), May 09 2010, IJmuiden, the Netherlands.
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 17 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 16 2002, Boulogne/Mer, France (50.42N,1.34E).
Herring
Gull 2cy (argenteus), May 11 2004, IJmuiden, the
Netherlands (52.27N 04.33E).
Herring
Gull 2cy (argenteus), May 11 2004, IJmuiden, the
Netherlands (52.27N 04.33E).
Herring
Gull 2cy (argentatus), May 01 2003, Boulogne/Mer, NW France.
Herring
Gull 2cy (argentatus), May 01 2003, Boulogne/Mer, NW France.