Herring Gull- Zilvermeeuw (argentatus & argenteus)
(last update: December 15, 2011
Herring Gull adults May
Above: 2015. Below: 2014.
Calais port services started to store materials and equipment on the Larus fuscus colony at the quay of the Loire in Calais. Some gulls (like orange OV, ringed the Netherlands and many more birds) are deprived from the location they occupied for so many years.
Already last year, a bulldozer destroyed some nests near the railway. At this location, quay of the Loire at Calais, about 200 Larus fuscus pairs breed (impossible to have a clear idea because of Buddleia grows on the railway).
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".
breeding Herring Gulls at Moerdijk
Continental European Herring Gull L. a. argenteus are known to show phenotypic characteristics which are intermediate between their British (L. a. argenteus) and Scandinavian relatives (L. a. argentatus). However, nothing has been published to date on the moult pattern and detailed phenotype of birds breeding in the Netherlands.
The industrial complex Moerdijk in the Netherlands holds a mixed colony of Herring and Lesser Black-backed Gulls. Colonisation of Moerdijk started in the early 1980s. By 2006, an estimated 650 pairs of Herring Gulls and 2900 pairs of Lesser Black-backed Gulls bred in the colony. In 2005, 157 breeding Herring Gulls and 434 Lesser Black-backed Gulls were colour ringed at Moerdijk, with 158 and 604, respectively, ringed in 2006.
We used these data collected at Moerdijk to describe the phenotypic characteristics and commencement of primary moult. Our data illustrate the large intra-population variability that exists for these taxa, even within a single colony. We discuss the implications of this variability for field identification of the various sub-species of Herring and Lesser Black-backed Gulls on this website.
Primary moult timing and strategy
By October the majority of adult Lesser Black-backed Gulls moulting the outer primaries. There is a clear difference between presumed birds lingering around and birds which will probably migrate further south quickly. The difference can be found in the primary moult strategy.
Some adult have a large moulting gap in the central primaries (for example P8-P10 old and only P4 fully grown and P5 still slightly shorter than P4) by the first days of September. It is hard to believe these birds will travel large distances non-stop as such moult gaps are highly inefficient for this migration pattern. Probably these birds, which can be found moulting in a period roughly from late August to late November stay in the area throughout their primary moult. They migrate further south either forced by cold winter or when the primaries moult arrives at the far outer primaries.
The other group is represented by birds with a very small moult gap in the primaries or with a very low primary moult score, indicating that primary moult will probably suspended until arrival at the wintering grounds.
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Herring Gull (argenteus) adult, May 27 2015, IJmuiden, the Netherlands (52.27N-04.33E). |
Herring Gull (argenteus) adult, May 27 2015, IJmuiden, the Netherlands (52.27N-04.33E). |
Tables & Graph
remaining SPRING
|
|
|
|
|
|
|
|
starting date:
|
30 Apr
|
07 May
|
14 May
|
21 May
|
04 Jun
|
11 Jun
|
30 Jul
|
week no:
|
18
|
19
|
20
|
21
|
23
|
24
|
31
|
0
|
0
|
0
|
0
|
0
|
|
|
0
|
1
|
0
|
0
|
0
|
0
|
|
|
0
|
2
|
0
|
0
|
0
|
0
|
|
|
1
|
3
|
0
|
0
|
0
|
0
|
|
|
1
|
4
|
0
|
0
|
0
|
0
|
|
|
37
|
5
|
0
|
0
|
0
|
0
|
|
|
22
|
6
|
0
|
0
|
0
|
0
|
|
|
3
|
7
|
3
|
2
|
1
|
2
|
|
|
0
|
8
|
16
|
22
|
26
|
18
|
1
|
1
|
0
|
9
|
30
|
13
|
16
|
10
|
1
|
|
0
|
10
|
66
|
33
|
37
|
10
|
|
|
0
|
|
|
|
|
|
|
|
|
n=
|
115
|
70
|
80
|
40
|
2
|
1
|
64
|
average REM P:
|
9.4
|
9.1
|
9.1
|
8.7
|
8.5
|
8.0
|
4.4
|
95% CID =
|
0.15
|
0.23
|
0.20
|
0.29
|
6.35
|
|
0.17
|
inverse =
|
1.98
|
1.99
|
1.99
|
2.02
|
12.71
|
|
2.00
|
Variantie (s2) =
|
0.68
|
0.90
|
0.84
|
0.83
|
0.50
|
|
0.46
|
SD (s) =
|
0.82
|
0.95
|
0.91
|
0.91
|
0.71
|
|
0.68
|
SE (sx) =
|
0.08
|
0.11
|
0.10
|
0.14
|
0.50
|
|
0.09
|
|
|
|
|
|
|
|
|
% class:
|
|
|
|
|
|
|
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
2
|
0
|
0
|
0
|
0
|
0
|
0
|
2
|
3
|
0
|
0
|
0
|
0
|
0
|
0
|
2
|
4
|
0
|
0
|
0
|
0
|
0
|
0
|
58
|
5
|
0
|
0
|
0
|
0
|
0
|
0
|
34
|
6
|
0
|
0
|
0
|
0
|
0
|
0
|
5
|
7
|
3
|
3
|
1
|
5
|
0
|
0
|
0
|
8
|
14
|
31
|
33
|
45
|
50
|
100
|
0
|
9
|
26
|
19
|
20
|
25
|
50
|
0
|
0
|
10
|
57
|
47
|
46
|
25
|
0
|
0
|
0
|
|
|
|
|
|
|
|
|
% control:
|
100
|
100
|
100
|
100
|
100
|
100
|
100
|
0 = 0 old primaries left (P10 dropped); 10 = all 10 primaries still old and present.
Above: Scatter Plot for PMS in adult Herring Gulls. Number of remaining old primaries throughout the year. Sample size is 1.329 birds.
new: SPRING |
|
|
|
|
starting date:
|
30 Apr
|
07 May
|
14 May
|
21 May
|
week no:
|
18
|
19
|
20
|
21
|
0
|
104
|
60
|
66
|
30
|
1
|
7
|
9
|
12
|
7
|
2
|
4
|
1
|
2
|
3
|
3
|
0
|
0
|
0
|
0
|
4
|
0
|
0
|
0
|
0
|
5
|
0
|
0
|
0
|
0
|
6
|
0
|
0
|
0
|
0
|
7
|
0
|
0
|
0
|
0
|
8
|
0
|
0
|
0
|
0
|
9
|
0
|
0
|
0
|
0
|
10
|
0
|
0
|
0
|
0
|
|
|
|
|
|
n=
|
115
|
70
|
80
|
40
|
average NEW P:
|
0.1
|
0.2
|
0.2
|
0.3
|
95% CID =
|
0.08
|
0.10
|
0.10
|
0.20
|
inverse =
|
1.98
|
1.99
|
1.99
|
2.02
|
Variantie (s2) =
|
0.18
|
0.16
|
0.21
|
0.38
|
SD (s) =
|
0.43
|
0.40
|
0.46
|
0.62
|
SE (sx) =
|
0.04
|
0.05
|
0.05
|
0.10
|
|
|
|
|
|
% class:
|
|
|
|
|
0
|
90
|
86
|
83
|
75
|
1
|
6
|
13
|
15
|
18
|
2
|
3
|
1
|
3
|
8
|
3
|
0
|
0
|
0
|
0
|
4
|
0
|
0
|
0
|
0
|
5
|
0
|
0
|
0
|
0
|
6
|
0
|
0
|
0
|
0
|
7
|
0
|
0
|
0
|
0
|
8
|
0
|
0
|
0
|
0
|
9
|
0
|
0
|
0
|
0
|
10
|
0
|
0
|
0
|
0
|
|
|
|
|
|
% control:
|
100
|
100
|
100
|
100
|
0 = no new primaries visible. So either P1 still old, or P1 dropped, but the very tip still not visible.
1 = P1 longest new primary. Range between "at least the tip of P1 is visible" until "tip of P2 still shorter than P1".
2 = P2 longest new primary. 3 = etc.
Above: Scatter Plot for PMS in adult Herring Gulls throughout the year. Longest new primary is classified "fully grown". Sample size is 3.271 birds. Birds scored on NEW primaries.
The first date in our analysis on adult Herring Gulls is 02 May 2006 (week 18 - starting 30 April), on which we already found birds with missing primaries (some birds had already shed 3 primaries). This group of actively moulting birds, 43% of the sample, must have started the complete moult somewhere around mid-April and probably several birds may have started earlier.
The last scoring day has been 03 December, when still 20% of the sampled birds had to grow P10. The final stage of the complete moult for all birds has to be somewhere after mid-December. On 03 December we scored 59 birds with P10 fully grown, 13 birds with P9 fully grown and 2 birds with P8 fully grown. They all had no old primaries left.
The first time a new primary (P1) was visible, was also on 02 May 2006 (week 18 - starting 30 April). In this week, 90% of the sample did not show new primaries, but 9% did. Four birds in the sample of 115 birds alreday had P2 as longest primary (fully grown). As soon as the tip of P1 was visible, this was automatically scored "fully grown", and this was the case in 7 birds. For the other primaries to be scored fully grown, they had to exceed the previous primary in length (so P2 fully grown, only from when it is longer than P1).
LINEAR REGRESSION
Onset of primary moult can best be illustrated by a sinusoid for the first few weeks and last weeks, but there appears to be linear dependency over much of the central moult period.
LINEAR REGRESSION FOR OLD REMAINING PRIMARIES
Complete sample: Linear regression (n = 1329, R2= 0.935, sign: P<0,000)
PMS = -0,379* WEEK + 16,324.
LINEAR REGRESSION FOR NEW FULLY GROWN PRIMARIES
Complete sample: Linear regression (n = 3271 R2= 0.927, sign: P<0,000)
PMS = 0,322* WEEK - 6,071.
Herring
Gull PS1T adult (argenteus), May 06 2012, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
Herring Gull (argenteus) UA9.T March 24 2010 & May 27 2015, IJmuiden, the Netherlands.
Herring
Gull MAA adult (argenteus), April-May 2012, Boulogne/Mer, France (50.42N,1.34E). Picture: J-M Sauvage.
Herring Gull (argenteus) S8 A adult, May 18 2010, Zeebrugge, Belgium. Picture: Peter Adriaens. 
Herring
Gull UZA adult (argenteus), May 04 2012, Calais, France (50.42N,1.34E). Picture: J-M Sauvage.
Herring
Gull
(argenteus) 5CY VPA May 18 2013, Calais, NW France. Picture: Jean-Michel Sauvage.
Herring
Gull 8+cy AAAA (argenteus), May 03 2003, Voorhaven, Zeebrugge, Belgium (51.59N
04.02E).
Herring
Gull 7+cy BUAH (argenteus), May 03 2003, Voorhaven, Zeebrugge, Belgium (51.59N
04.02E).
Herring Gull
(argenteus) 6CY-8CY CKAL March 2013 & May 2015, Calais, NW France. Picture: Jean-Michel Sauvage.
Herring Gull (argenteus) CTAJ adult, May 30 2011, Zeebrugge, Belgium. Picture: Peter Adriaens.
Herring Gull (argenteus) FAAR adult, May 14 2010, Zeebrugge, Belgium. Picture: Peter Adriaens. 
Herring Gull (argenteus) FAAW 5CY (4th cycle), May 20 2010, Zeebrugge, Belgium. Picture: Peter Adriaens.
Herring Gull (argenteus) FBAF 5CY (4th cycle), May 11 2010, Zeebrugge, Belgium. Picture: Peter Adriaens.
Herring Gull (argenteus) FBAV adult, May 21 2010, Zeebrugge, Belgium. Picture: Peter Adriaens. 
Herring Gull (argenteus) FDAL 5CY (4th cycle), May 11 2010, Zeebrugge, Belgium. Picture: Peter Adriaens.
Herring Gull (argenteus) FGAY adult, May 18 2010, Zeebrugge, Belgium. Picture: Peter Adriaens. 
Herring Gull (argenteus) FMAX adult, May 22 2011, Koksijde, Belgium. Picture: Peter Adriaens. 
Herring Gull (argenteus) FNAB 5CY (4th cycle), May 11 2010, Zeebrugge, Belgium. Picture: Peter Adriaens.
Herring Gull (argenteus) GFAU adult, May 11 2010, Zeebrugge, Belgium. Picture: Peter Adriaens. 
Herring Gull (argenteus) KNAT adult, May 2010 & January - February 2012, Belgium. Picture: Peter Adriaens. 
Herring Gull (argenteus) SBAJ 8CY, January - November 2012, Koksijde, Belgium. Picture: Peter Adriaens. 
Herring Gull
(argenteus) H-131757 11CY, May 11 2014, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
Herring
Gull H-132860 adult (argenteus), April-July 19 2012, Calais, France. Picture: J-M Sauvage.
Herring
Gull H133694 adult (argenteus), May & June 2010, Leiden, Netherlands.
Herring Gull adult H-137233 (argenteus) August - September 2012 & May 2014, Katwijk, the Netherlands.
Herring Gull (argenteus) BLB H-149106 adult, May 05 2016, Neeltje Jans, the Netherlands (51°38'17.74"N 3°42'27.05"E). 
Herring Gull (argenteus) Y.AAF adult, May 19 2014, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Herring Gull (argenteus) Y.ACW 1CY & 7CY, August 2008 & May 2014, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee & Mars Muusse.
Herring Gull (argenteus) Y.ADH 1CY, 6CY & 10CY, August 2008, June 2013 & May 2017, the Netherlands. 
Herring Gull (argenteus) Y.AFC 1CY, 4CY & 10CY, August 2008, May 2011 & May 2017, IJmuiden & Heemskerk, the Netherlands.
Herring
Gull Y.AHB adult (argenteus), 2010 - 2011, IJmuiden, the Netherlands.
Herring
Gull Y.AHC adult (argenteus), May 06 2011, IJmuiden, the Netherlands.
Herring Gull (argenteus) Y.ALP 2CY & 9CY, October 2010 & May 2017, Westkapelle & Heemskerk, the Netherlands.
Herring Gull (argenteus) Y.BBZ adult, May 19-26 2014, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Herring Gull
(argenteus) YBHA adult, February 19 2016 & May 29 2017, IJmuiden & Heemskerk, the Netherlands. 
Herring Gull (argenteus) Y.BHN adult, May 2014 & April 2016, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Herring Gull (argenteus) Y.BJZ adult, May 26 2014, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Herring Gull (argenteus) Y.BKD adult, May 2014 & September 2016, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee & Mars Muusse.
Herring Gull (argenteus) Y.BKP adult, May & August 2016, IJmuiden, the Netherlands. 
Herring Gull (argenteus) Y.BNL adult, May 26 2014, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Herring Gull (argenteus) Y.CAC adult, May 29 2017, Heemskerk, the Netherlands.
Herring Gull (argenteus) Y.CAK adult, May 29 2017, Heemskerk, the Netherlands.
Herring Gull (argenteus) Y.CAN adult, May 29 2017, Heemskerk, the Netherlands.
Herring Gull (argenteus) Y.CHH sub-adult, May 29 2017, Heemskerk, the Netherlands.
Herring Gull (argenteus) Y.CJS adult, May - June 2017, Heemskerk, the Netherlands.
Herring
Gull M.AAP adult (argenteus), May 07 2011, Texel, the Netherlands.
Herring
Gull M.ACZ adult (argenteus), May & June 2011, Texel, the Netherlands.
Herring Gull (argenteus) M.ALR 4CY & 11CY, September 2010 & May 2017, IJmuiden & Texel , the Netherlands. Pictures: Maarten van Kleinwee & Mars Muusse.
Herring Gull (argenteus) M.AMH adult, February & May 2014, the Netherlands. Picture: Theo Muusse & Maarten van Kleinwee.
Herring Gull (argenteus) M.APT adult, May 02 2017, Hoornderslag - Texel, the Netherlands. 
Herring Gull (argenteus) M.ATC adult, May 02 2017, Hoornderslag - Texel, the Netherlands. 
Herring Gull (argenteus) M.ATD adult, May 02 2017, Hoornderslag - Texel, the Netherlands. 
Herring Gull (argenteus) M.ATN adult, May 02 2017, Hoornderslag - Texel, the Netherlands. 
Herring
Gull F.AAN adult (argenteus), May 07 2011, Texel, the Netherlands.
Herring
Gull F.ADC adult (argenteus), May 07 2011, Texel, the Netherlands.
Herring
Gull F.AFN adult (argenteus), May 07 2011, Texel, the Netherlands.
Herring
Gull F.AHK adult (argenteus),May & June 2011, Texel, the Netherlands.
Herring Gull (argenteus) F.AWP adult, May 02 2017, Hoornderslag - Texel, the Netherlands. 
Herring Gull (argenteus) PCHC 11CY, January & May 2017, Scheveningen, the Netherlands. 
Herring
Gull DA 24-27cy (argenteus, 2009-2010, Leiden, Netherlands.
Herring Gull (argenteus) NLA 5.277.846 13CY-24CY, 2004-2015, IJmuiden, the Netherlands (52.27N-04.33E).
Herring Gull argenteus NLA 5.352.687 13CY & 16CY, November 2013 & May 2016, Katwijk aan Zee, the Netherlands.
Herring
Gull (argenteus) NLA.5.352.764 10cy, May 2011, IJmuiden, the Netherlands. Seen in eight years now.
Herring
Gull NLA.5.344.303 12cy (argenteus), May 06 2011, IJmuiden, the Netherlands.
Herring
Gull NLA 5.335.x52 adult (argenteus), May 06 2007, IJmuiden, the Netherlands.Yellowish legs.
Herring Gull (argenteus) NLA 5.414.283 13CY, May 02 2017, Hoornderslag - Texel, the Netherlands. 
Herring
Gull 5.419.235 5cy (argenteus), 2010-2011, Leiden, Netherlands.
Herring Gull (argenteus) NLA 5.294.06x 21CY, May 27 2015, IJmuiden, the
Netherlands (52.27N-04.33E).
Herring Gull (argenteus) NLA 5.42x.xxx adult, May 27 2015, IJmuiden, the
Netherlands (52.27N-04.33E).
Herring Gull argenteus NLA 6.166.442 1CY & 8CY, September 2010 & May-June 2017, IJmuiden - Katwijk, the Netherlands. Pictures: Maarten van Kleinwee & Mars Muusse.
Herring Gull
(argenteus) NLA 6.169.883 2CY & 5CY, July - August 2013 & May 2016, Katwijk, the Netherlands.
Herring
Gull PL 24cy female (argenteus), 07 May 2006. Breeding bird at Moerdijk, Netherlands.
hybrid PA 11cy (argenteus x michahellis), May 06 2007, Neeltje Jans, the Netherlands.
Herring
Gull S0 19cy male (argenteus), 06 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 1A 17cy female (argenteus), 04 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull VE 14-15cy (argenteus), 21 May 2005 & 16 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull C0 14cy female (argenteus), 06 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 10 13cy male (argenteus), 05 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring Gull argenteus 6E adult female, May 2005 & April 2014, Moerdijk-Sassenplaat, the Netherlands. Picture: Merijn Loeve. 
Herring
Gull JK 11cy male (argenteus), 05 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull HL 11cy female (argenteus), 04 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull H2 11cy male (argenteus), 05 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull KL 10cy male (argenteus), 09 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull LN 9cy male (argenteus), 13 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull P3 9cy male (argenteus), 16 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 64 9cy male (argenteus), 21 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull NE 8cy male (argenteus), 16 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring Gull (argenteus) JP adult female, May 06 2006, Moerdijk, the Netherlands. Grey tone: Kodak 3.
Herring
Gull JX 8cy male (argenteus), 06 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull KU 8cy male (argenteus), 09 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 59 8cy female (argenteus), 21 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 2Z 8cy male (argenteus), 06 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull K2 7cy (argenteus), 09 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 4T 7cy female (argenteus), 16 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 42 7cy female (argenteus), 16 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 18 7cy male (argenteus), 05 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 3E 7cy female (argenteus), 14 May 2005. Breeding bird at Moerdijk, Netherlands.
Herring
Gull K4 6cy male (argenteus), 09 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull J7 6cy male (argenteus), 09 May 2006. Breeding bird at Moerdijk, Netherlands.
Herring
Gull 3T 6cy (argenteus), 14 May 2005. Breeding bird at Moerdijk, Netherlands.
hybrid PA 10cy (argenteus x michahellis), May 07 2006, Neeltje Jans, the Netherlands.
Herring Gull (argenteus) 0.N adult, October 2011 & May 2014, Scheveningen & Maasvlakte, the Netherlands.
Herring Gull argenteus GY adult, May 2014, Vlissingen colony, the Netherlands. Picture: Merijn Loeve. 
Herring Gull (argenteus) T.R 4CY-5CY, April 2016 & May-June 2017, Katwijk, the Netherlands.
Herring Gull argenteus 0M adult, May 2014, Stuwencomplex Amerongen, the Netherlands. Picture: Merijn Loeve. 
Herring Gull (argenteus) 1.E adult, May 10 2018, Maasvlakte, the Netherlands.
Herring Gull argenteus 1F adult, May 2014, Maasvlakte, the Netherlands. Picture: Merijn Loeve. 
Herring Gull argenteus 1Z sub-adult (5CY), May 2014, Maasvlakte, the Netherlands. Picture: Merijn Loeve. 
Herring Gull (argenteus) 4.8 5CY, May 10 2018, Maasvlakte, the Netherlands.
Herring Gull (argenteus) 4.E 5CY, May 10 2018, Maasvlakte, the Netherlands.
Herring Gull (argenteus) A.1 adult, May 29 2015, Katwijk, the Netherlands. Picture: Merijn Loeve.
Herring Gull (argenteus) A.A adult, May 29 2015, Katwijk, the Netherlands. Picture: Merijn Loeve.
Herring Gull (argenteus) A.J adult, May 2015 & October 2016, Katwijk, the Netherlands. Picture: Merijn Loeve & Mars Muusse.
Herring Gull (argenteus) A.M adult, May 2015 & December 2016, Katwijk, the Netherlands. Picture: Merijn Loeve & Mars Muusse.
Herring Gull (argenteus) A.P adult, May 29 2015, Katwijk, the Netherlands. Picture: Merijn Loeve.
Herring Gull (argenteus) A.R adult, May 29 2015, Katwijk, the Netherlands. Picture: Merijn Loeve.
Herring Gull argenteus CC adult, May 2014, Maasvlakte, the Netherlands. Picture: Merijn Loeve. 
Herring Gull argenteus J4 adult, May 2014, Maasvlakte, the Netherlands. Picture: Merijn Loeve. 
Herring Gull argenteus JB adult, August 2015, May 2016 - May 2017, Katwijk, the Netherlands.
Herring Gull (argenteus) N.H adult, May 2015 & September 2016, Katwijk, the Netherlands. Picture: Merijn Loeve & Mars Muusse.
Herring Gull (argenteus) AY adult, May 10 2018, Dintelhaven - Europoort, the Netherlands.
Herring Gull argenteus AZ and CL adult, May 2016 & May 2018, Europoort - Dintelhaven, the Netherlands (51.57 N 4.06 E).
Herring Gull (argenteus) BA adult, May 10 2018, Dintelhaven - Europoort, the Netherlands.
Herring Gull (argenteus) CG adult, May 10 2018, Dintelhaven - Europoort, the Netherlands.
Herring Gull K5 adult, May 24 2016, Katwijk aan Zee, the Netherlands.
Herring Gull (argenteus) UY adult, May 10 2018, Dintelhaven - Europoort, the Netherlands.
Herring Gull (argenteus) NLA 6.173.75x adult, May 10 2018, Maasvlakte, the Netherlands.
Herring Gull argentatus adult, May 17 2009, Tarastenjärvi dump - Tampere, Finland. Picture: Visa Rauste. 
Herring Gull argenteus adult, May 11 2014, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
Herring
Gull (argenteus), May 03 2003, Voorhaven, Zeebrugge,
Belgium (51.59N
04.02E).
Herring Gull argenteus adult, May 20 2014, Katwijk, the Netherlands. 
Herring Gull argenteus adult, May 20 2014, Katwijk, the Netherlands. 
Herring Gull argenteus adult, May 13 2014, Katwijk, the Netherlands. 
Herring Gull argenteus adult, May 13 2014, Katwijk, the Netherlands. 
Herring Gull argenteus adult, May 13 2014, Katwijk, the Netherlands. 
Herring
Gull adult (argenteus), May 12 2001, Westkapelle, the
Netherlands (51.33N 03.25E). Picture by Pim Wolf.
Herring
Gull adult (argenteus), May 12 2002,
Missouriweg, Maasvlakte, the Netherlands (51.59N
04.02E).
Bird died last week.
Herring
Gull adult (argenteus), May 13 2002,
Dintelhaven, Maasvlakte, the Netherlands (51.59N
04.02E).
Bird died today.