Herring Gull (argentatus & argenteus)
(last update: February 11, 2013)
Herring Gull (argentatus) KN80 12CY, January 22 2015, Le Portel, France. Picture: Jean-Michel Sauvage.
Ringed metal RUM Moskwa HA-000 034 and plastic white KN80. SPECIES Larus argentatus
Ringed as pullus on July 10 2004, at Kandalakshskiy Nature Reserve, Severnoe lesnichestvo, isl. Farvaternaya, Murmansk O., Russia (67.05 N 32.29 E).
Recoveries:
09.03.2006 France, Nord, Blaringhem (rubbish dump) 50.41 N 2.24 E
11.12.2008 France, Pas-de-Calais, Dannes (rubbish dump) 50.35 N 1.36 E
18.02.2009 France, Nord, Blaringhem (rubbish dump) 50.41 N 2.24 E
16.02.2012 France, Nord, Blaringhem (rubbish dump) 50.41 N 2.24 E
18.02.2013 France, Pas-de-Calais, Wimereux beach 50.46 N 1.36 E
07.03.2013 France, Nord, Blaringhem rubbish dump 50.41 N 2.24 E
18.12.2013 France, Pas-de-Calais, Dannes 50.35 N 1.36 E
05.02.2014 France, Pas-de-Calais, Dannes 50.35 N 1.36 E
22.01.2015 France,Pas-de-Calais,Le-Portel "beach" 50.42N 01.34E JMS.
DISTANCE 2493 km DIRECTION 223 degrees.
No black on P5. Image is photoshopped, with standing and flying bird.
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 particularly 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.
Extensive research on the P10 pattern of Scandinavian argentatus was done for Norwegian birds by the Norwegian ornithologist 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 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 |
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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.