Herring Gull- Zilvermeeuw (argentatus & argenteus)

(last update: December 15, 2011 )

Herring Gull - 4cy /sub-adults November

Thumbnails in the column right illustrate plumage characteristics of ringed and unringed immature Herring Gull (4CY & 5CY birds) for the month of November.

Some remarks on ID of argentatus vs argenteus

Herring Gulls breeding in Europe are variable in upper-part coloration, measurements and wingtip pattern. Argentatus,breeding in Scandinavia, is large and snouty, has grey upper-parts, shows limited black in the wingtip and northern populations may migrate 2000+ km’s south in autumn.
Western populations are called British Herring Gull argenteus, which are smaller, have paler grey upper-parts, more black in the wingtip and many do not migrate at all, or have short distance dispersion along the Atlantic coast. There is a cline between the Herring Gull populations in the North Sea bassin.
Most of this general picture was constructed by extensive research by the Norwegian ornithologist E. K. Barth, published as Contribution No. 86, Zoological Museum, University of Oslo, called "The circumpolar systematics of Larus argentatus and Larus fuscus with special reference to the Norwegian populations".

Already in the 1960’s, Barth’s research described variation in upper-part grey tones and in wingtip patterns within any of the single populations. Due to indivudual variation, at locations where both taxa are present or expected, it is often only possible to assign individual bird to either taxon argentatus or argenteus if birds are ringed as chick, or when classic birds in the extremes of the continuum are observed at the right location, in the right season.
Here we show some example birds from various populations.

Upperpart grey tone in adults

Reserach by Barth introduced the split in Herring Gull into argentatus and argenteus. Below, a map with clustered column charts for NE populations, for various locations. Click the thumbnails on the map to enlarge graphs (figures have been prepared with most care, yet I take full responsibility for any errors in charts).

Wingtip patterns in adults

The differences between typical western argenteus from the U.K. and northern Scandinavian argentatus is rather straightforward on primary pattern P5-P10. However, there is a gradient and overlap in features of birds from populations in northern Germany, Denmark and southern Norway. 
Identification is even more challenging in birds from Baltic populations, which show both characteristics of argenteus and argentatus, but sometimes also of the southern taxa michahellis and cachinnans.
Adult birds from the western populations argenteus show more black in the outer primaries, compared to northern argentatus. In argenteus, P5 normally shows small black sub-terminal markings, 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, although this might be a clue for near-adult birds. In argentatus, especially from far northern Scandinavia, the black marking on P5 is completely lacking or is very limited and diffuse.
Argenteus
often has a black sub-terminal band on the top of P10, dividing the tip from the mirror. If the black sub-terminal band on P10 is broken, there is often still black on the inner and outer-web's edge of P10. Normally argentatus lacks sub-terminal markings on the outer-web of P10.

Baltic argentatus often have the black marking on P5 confined to the outer-web as a single rectangular small black square, with well-defined borders (not diffuse as in most Finnmark birds). In most Baltic birds, the white tip of P10 fully merges with the mirror, without a single sign of a sub-terminal band. The greyish-white 'tongue' on the inner-web is often broad and continues far down P10, almost creating a thayeri pattern on P10. The shape of the division line between greyish tongue and black outer-web can be an identification clue: In cachinnans this division line often makes a strong angular curve and has a smooth straight line, unlike the pattern of Herring Gulls, which often show a "saw-blade" motive or otherwise much irregularities along the division line. Sometimes wear of the outer primaries may be useful as a first indication of origin: An early moulting species as cachinnans on average show more abrasion in the feathers than later moulting argentatus.

In the table below you find pattern sof P9 and P10 in Scandinavian argentatus.

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 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 tip
1: 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

Especially birds from north Scandinavian Finnmark may show the characteristic 'thayeri' pattern in the outer primaries P9 and P10 (column 5 of tip pattern P9 in the table). This pattern is named after the Thayer's Gull, which often shows a particular pattern in the outer primaries: the mirror and the white tip merge and are connected to the pale inner-web (see this image). In other words: the black medial band of the outer-web doesn't fully reach the edge of the inner-web and there is no sub-terminal band. In Thayer's Gull this pattern may be very obvious and, together with the 'string of pearls' may be indicative for identification. 

 

rings argenteus: UK.
adult argentatus in November, ringed in Denmark. (56984 bytes)Herring Gull KU4T 4cy (argenteus), November 26 2012, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
2cy argentatus in February, ringed in Norway. (75189 bytes)Herring Gull VX7T 3CY-4CY, June 2013 & November 2014, Koksijde & Oostende, Belgium. Picture: Peter Adriaens.
rings argenteus: Belgium
sub-adult argenteus in November, ringed in Belgium. (80555 bytes)Herring Gull AVAW 5cy (argenteus), November 15 2003, Westkapelle, the Netherlands (51.33N 03.25E).
sub-adult argenteus in November, ringed in Belgium. (45415 bytes)Herring Gull AYAR 4cy (argenteus), November 16 2002, Westkapelle, the Netherlands (51.33N 03.25E).
sub-adult argenteus in November, ringed in Belgium. (49193 bytes)Herring Gull BHAK 4cy (argenteus), November 16 2002, Westkapelle, the Netherlands (51.33N 03.25E).
1cy argenteus in November, ringed in Belgium. (25637 bytes)Herring Gull FCAV 4cy (argenteus), August-November 2009, Westkapelle, the Netherlands.
sub-adult argenteus in November, ringed in Belgium. (84125 bytes)Herring Gull H-112037 4cy (argenteus), November 15 2003, Westkapelle, the Netherlands (51.33N 03.25E).
Herring GullHerring Gull H-126690 sub-adult, November 26 2006, Oostende, Belgium. No provenance, ringed on the beach in winter. Probably 5cy.
Herring GullHerring Gull H-136532 4cy, November 26 2006, Oostende, Belgium.
Herring GullHerring Gull H-136703 sub-adult, November 26 2006, Oostende, Belgium. No provenance, ringed on the beach in winter. Probably argentatus.
Herring GullHerring Gull H-136714 sub-adult, November 26 2006, Oostende, Belgium. No provenance, ringed on the beach in winter.
rings argenteus: the Netherlands
3cy Herring Gull in August, ringed in Belgium. (84363 bytes)Herring Gull (argenteus) Y.BDS 1CY-4CY, September 2012 - November 2015, IJmuiden, the Netherlands. Pictures: Maarten van Kleinwee & Mars Muusse.
3cy Herring Gull in August, ringed in Belgium. (84363 bytes)Herring Gull (argenteus) Y.CAX 4CY, May, August & November 2016, IJmuiden & Katwijk, the Netherlands. Picture: Maarten van Kleinwee & Mars Muusse.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Herring Gull (argenteus) KD 2CY-4CY, November 2014 - November 2016, Katwijk & IJmuiden, the Netherlands.
sub-adult argenteus in November, ringed in ther Netherlands. (86160 bytes)Herring Gull 5.334.963 5cy (argenteus), November 15 2003, Westkapelle, the Netherlands (51.33N 03.25E).
3cy argenteus in November, ringed in the Netherlands. (74478 bytes)Herring Gull 5.366.547 4cy (argenteus), November 15 2003, Westkapelle, the Netherlands (51.33N 03.25E).
1cy argenteus in August, ringed in Belgium. (90559 bytes)Herring Gull NLA.5.424.838 sub-adult (argenteus), November 2009 & December 2010, IJmuiden, the Netherlands.
3cy argenteus in November, ringed in the Netherlands. (74478 bytes)Herring Gull 5.434.678 4cy (argenteus), November 02 2008, Amsterdam, the Netherlands.
sub-adult argenteus in November, ringed in ther Netherlands. (90289 bytes)Herring Gull E sub-adult (argenteus), November 15 2002, Scheveningen, the Netherlands (52.06N 04.16E).
Herring GullHerring Gull 5.038.584 adult (argenteus), November 15 2003, Westkapelle, the Netherlands (51.33N 03.25E).
Ringed as breeding >4cy in 2002, but dark on primary coverts.

rings argentatus: Germany

Herring GullHerring Gull AF57 sub-adult (argenteus), November 16 2002, Brouwersdam, the Netherlands 51.45N 03.51E).
Herring GullHerring Gull AFV1 sub-adult (argenteus), November 13 & 26 2006, Westkapelle, Netherlands and Oostende, Belgium.
rings argentatus: Norway
2cy argenteus in November, ringed in the Netherlands. (65412 bytes)Herring Gull (argentatus) J6785 2CY & 4CY, November 2014, February 2016 & November 2016, Katwijk & Terschelling, the Netherlands. Picture: Jacob Jan de Vries & Mars Muusse.
1cy argenteus in August, ringed in Belgium. (90559 bytes)Herring Gull argentatus J8522 sub-adult, November 05 2016, Stavanger, Norway. Picture: Rubén Piculo Mateo.
Herring GullHerring Gull (argentatus) JL529 2CY, 3CY, 4CY, March 2014 - November 2016, Leiden-Katwijk, the Netherlands. Picture: Maarten van Kleinwee & Mars Muusse.

rings argentatus: Russia

Herring GullHerring Gull (argentatus) KW37 4CY, November 06 2015, Terschelling, the Netherlands. Picture: Jacob Jan de Vries. 
unringed 4cy Herring Gulls
Herring GullHerring Gull argentatus sub-adult, November 24 2016, Katwijk, the Netherlands.
Herring GullHerring Gull argentatus sub-adult, November 24 2016, Katwijk, the Netherlands.
Herring GullHerring Gull (argentatus) 4cy, November 20 2012, Katwijk, the Netherlands. Mirror on P9 and P10.
Herring GullHerring Gull (argentatus) 4cy, November 20 2012, Katwijk, the Netherlands.
Herring GullHerring Gull (argenteus) 4cy, November 20 2012, Katwijk, the Netherlands.
Herring GullHerring Gull (argenteus) 4cy, November 20 2012, Katwijk, the Netherlands.
Herring GullHerring Gull (argentatus) sub-adult, November 17 2014, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 26 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull sub-adult, November 12 2015, Katwijk, the Netherlands.
Herring GullHerring Gull 4cy, November 20 2012, Katwijk, the Netherlands. Mirror on P10.
Herring GullHerring Gull sub-adult, November 17 2014, Katwijk, the Netherlands.
Herring GullHerring Gull 4cy, November 20 2012, Katwijk, the Netherlands. Mirror on P9 and P10.
Herring GullHerring Gull sub-adult, November 20 2012, Katwijk, the Netherlands. Mirror on P10.
Herring GullHerring Gull sub-adult, November 26 2013, Katwijk aan Zee, the Netherlands.
Herring GullHerring Gull sub-adult, November 26 2013, Katwijk aan Zee, the Netherlands.
Herring GullHerring Gull sub-adult, November 26 2013, Katwijk aan Zee, the Netherlands.
Herring GullHerring Gull argentatus sub-adult, November 26 2013, Katwijk aan Zee, the Netherlands.
sub-adult argenteus in November. (55122 bytes)Herring Gull sub-adult (argentatus), November 28 2011, Scheveningen, the Netherlands.
sub-adult argenteus in November. (55122 bytes)Herring Gull sub-adult (argentatus), November 28 2011, Scheveningen, the Netherlands.
sub-adult argenteus in November. (55122 bytes)Herring Gull sub-adult, November 28 2011, Scheveningen, the Netherlands.
sub-adult argenteus in November. (55122 bytes)Herring Gull sub-adult (argentatus), November 28 2011, Scheveningen, the Netherlands.