Herring
Gull - Zilvermeeuw (argentatus & argenteus)
(last update: 31 maart 2004)
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(6 images) Herring Gull adult X994, Le Portel / Boulogne-sur-Mer, France (50.44N-01.34E).
Ringed as pullus on June 28 1996 on the island of Heuwiese, 15 km north of Stralsund (NE Germany in the East Sea), ringed green X994. The October 02 2001 recovery was after 1922 days and 884 km direction WSW (246°43') from the place of ringing. Green X994 probably spend the summers somewhere in Germany and it's reported on almost every winter occasion at Le Portel, where it stays in the early months of the winter (before moving further south?) and again on it's way back to the breeding grounds in February and March. By the first week of October 2001, X994 has primary P5 fully grown and P6 almost at it's final length.
image below: X994 6cy, October 02 2001, Le Portel, France.
The populations of argentatus north of Rostock (NE Germany) show intermediate characteristics of both argenteus and argentatus. This is nicely demonstrated by X994:
- X994 is medium grey on the upper-parts, matching Baltic argentatus. Argenteus from the UK and the Netherlands are slightly paler, argentatus from northern Norway are darker grey.
- On P10, the tip
completely merges with the mirror in X994, a feature commonly found in argentatus.
Adult argenteus normally shows a complete black sub-terminal
band or reduced sub-terminal black at the edge of the inner-web and
outer-web (broken sub-terminal band at the centre). Only a small
minority of western argenteus completely lacks any sub-terminal
markings. The P10 pattern of Scandinavian argentatus was best
investigated for Norwegian birds by the late Edvard Barth, and is
presented in the table below:
Table 4 from E.K. Barth, The circumpolar systematics of Larus argentatus and Larus fuscus with special reference to the Norwegian populations, 1968. 200 Norwegian birds. (Notation converted to what we use in the texts, MM). locality sample size tip pattern P10 tip pattern P9 colour of P10 inner-web black spotting present from P10 to: 1 2 3 4 1 2 3 4 5 1 2 3 5 6 P7 P6 P5 P4 East Finnmark 15 n 10 1 2 2 5 4 1 1 4 5 7 3 12 3 - 10 5 - % 67 7 13 13 33 27 7 7 27 33 47 20 80 20 - 67 33 - Tamsöy in Central Finnmark 33 n 17 7 6 3 10 10 6 0 7 12 20 1 23 10 - 19 13 1 % 52 21 18 9 30 30 18 - 21 36 61 3 70 30 - 58 39 - Troms 29 n 17 8 3 1 11 9 4 1 4 3 20 6 24 5 - 24 5 - % 59 28 10 3 38 31 14 3 14 10 69 21 83 17 - 83 17 - Bodö and Röst 32 n 15 10 3 2 19 3 5 0 3 3 24 5 27 5 1 18 13 - % 50 33 10 7 63 10 17 - 10 9 75 16 84 16 3 56 41 - Tarva 20 n 8 7 3 2 11 5 4 0 0 10 8 2 12 8 1 7 10 2 % 40 35 15 10 55 25 20 - - 50 40 10 60 40 5 35 50 10 Stavanger and Lindesnes 42 n 18 13 4 6 23 12 3 2 2 15 23 4 37 5 - 13 29 - % 44 32 10 14 55 28 7 5 5 36 55 9 88 12 - 31 69 - Oslo Fiord 29 n 19 6 3 1 20 1 4 1 2 12 14 3 24 5 - 17 12 - % 66 21 10 3 71 4 14 4 7 42 48 10 83 17 - 59 41 - 1: all white
2: trace of black near tip
3: incomplete black bar near tip
4: complete black bar or black tip1: broad white band over both webs
2: white spot on both webs
3: white spot on inner web only
4: no white spot present
5: 'thayeri-pattern'1: like mantle colour
2: slightly lighter than mantle colour
3: markedly lighter than mantle colour
5: relatively sharp border between black and grey
6: gradual transition from black to grey - The black patch between the grey centre and the white mirror, the "medial band", is relatively broad in primary P10 on X994 (see images from February 2003). This medial band extends over quite a range on the inner-web, a feature commonly shared by western argenteus. As the table above shows, northern argentatus may have the medial band very limited along the inner-web of P10 and in some northern birds, this medial band doesn't reach the inner-web at all, creating a thayeri pattern on P10. Such a P10 thayeri pattern is very obvious in this image (click hyperlink). A thayeri pattern can be obvious on P9 and this feature was investigated by E. Barth, as the second column in the above table shows. Such a thayeri pattern can be found more commonly in northern argentatus populations.
- X994 has only limited black on primary P5, with the black confined to a straight line on the inner-web. The black streak has diffuse edges. Argentatus populations from far northern Scandinavia have very limited black on P5, often only a diffuse streak on the outer-web. Quite some northern argentatus completely lack any black on P5. In argenteus, the black on P5 is normally well-developed, either as a solid square mark on the outer-web or a complete black sub-terminal band. West-European argenteus have a well-developed black square sub-terminal mark on the outer-web of P5 or a complete sub-terminal band, extending over both inner and outer-web.
- Although already in 6th calendar year (October 2001), X994 still show an immature bill-pattern, with a clear division of the yellow tip and pinkish base. Also, the bill still shows a faint black band. The iris is not clear yellow, but slightly whitish hued. By mid-winter (January 2002) the iris is pure yellow as in adults. On average, argentatus seem to show immature characteristics over a longer period, although data on this feature are limited, more research would be necessary.
- The orbital ring is deep red by January (see image below). Argenteus normally has the orbital ring yellowish-orange or orange. Argentatus may show coral red or scarlet red orbital rings.
image below: X994 7cy, January 04 2002, Le Portel, France.
From June to October, adult Herring
Gull have a complete moult to so-called "winter plumage". In
this moult all primaries, rectrices and secondaries are replaced. P5 shows small black sub-terminal markings in argenteus,
concentrated on the outer-web as a clear-cut black angular spot and in
some birds extending on the inner-web as a diffuse streak. There may be some black on
P4 as well, but maybe only in near-adult birds. Adult argenteus show a different pattern in the outer
primaries, compared to northern argentatus. In argentatus,
especially from northern Scandinavia, the black marking on P5 is very
limited and diffuse or this is sub-terminal marking is completely
lacking on P5.
Argenteus has more black in the outer primaries, including a black
band on the top of p10 in most birds, dividing the tip from the mirror. If
the black sub-terminal band on P10 is broken, the outer-web of p10 still
shows black marking. Argentatus normally lacks sub-terminal
markings on the outer-web of P10.
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
yellowish or yellow-orange in argenteus; slightly orange-red or
coral red in argentatus. The legs are flesh-pink in argenteus, but
may show a yellowish hue or appear very clear yellow in some argentatus
(from either the Baltic region or far northern Finnmark).
image below: X994 7cy, October 24 2002, Le Portel, France.
Information about the recoveries were generated by Hiddensee Bird Ringing Center, LUNG Mecklenburg-Vorpommern. You can find all kind of information on their website: http://www.hnm.de/vv/beringung/homepage.htm, not only about gulls but also about passerines, about facts for ringers, new computer software, etc. (all in German).
| co-ordinates | place | year | date of recovery, data by Hiddensee Bird Ringing Center, LUNG | |
| 54°26'N-013°08'E | Germany: Heuwiese | 1996 | 28.06.1996 (pullus) | |
| 54°19'N-013°05'E | Germany: Stralsund, Hansestadt | 1996 | 25.09.1996 | |
| 54°57'N-012°28'E | Denmark: Klintholm, Sjaelland | 1996 | 13.10.1996 | |
| 50°44'N-001°35'E | France Le Portel | 1997 | 01.02.1997-02.03.1997 (seen 5x) | 18.06.1997-22.11.1997 (seen 10x) |
| 50°44'N-001°35'E | France Le Portel | 1998 | 19.09.1998-25-12-1998 (seen 6x) | |
| 50°44'N-001°35'E | France Le Portel | 1999 | 05.01.1999-18.02.1999 (seen 7x) | 23.08.1999-10.10.1999 (seen 5x) |
| 50°44'N-001°35'E | France Le Portel | 2000 | 09.02.2000-02.03.2000 (seen 2x) | 15.09.2000-26.10.2000 (seen 6x) |
| 50°44'N-001°35'E | France Le Portel | 2001 | 25.01.2001 | 16.08.2001-15.10.2001 (seen 6x) |
images below: X994 8cy, February 07 2003, Le Portel, France.
image below: X994 8cy, August 11 2003, Le Portel, France.
image below: X994 13cy, August 13 2008, Le Portel, France.
