Lesser Black-backed Gull - graellsii & intermedius

Lesser Black-backed Gull (graellsii & intermedius)

(last update: 14-11-2017 )

lbbg 1cy May
lbbg 1cy June
lbbg 1cy July
lbbg 1cy August
lbbg 1cy September
lbbg 1cy October
lbbg 1cy November
lbbg 1cy December

lbbg 2cy January
lbbg 2cy February
lbbg 2cy March
lbbg 2cy April
lbbg 2cy May
lbbg 2cy June
lbbg 2cy July
lbbg 2cy August
lbbg 2cy September
lbbg 2cy October
lbbg 2cy November
lbbg 2cy December

lbbg 3cy January
lbbg 3cy February
lbbg 3cy March
lbbg 3cy April
lbbg 3cy May
lbbg 3cy June
lbbg 3cy July
lbbg 3cy August
lbbg 3cy September
lbbg 3cy October
lbbg 3cy November
lbbg 3cy December

lbbg sub-ad January
lbbg sub-ad February
lbbg sub-ad March
lbbg sub-ad April
lbbg sub-ad May
lbbg sub-ad June
lbbg sub-ad July
lbbg sub-ad August
lbbg sub-ad Sept
lbbg sub-ad Oct
lbbg sub-ad Nov
lbbg sub-ad Dec

lbbg adult January
lbbg adult February
lbbg adult March
lbbg adult April
lbbg adult May
lbbg adult June
lbbg adult July
lbbg adult August
lbbg adult September
lbbg adult October
lbbg adult November
lbbg adult December

adult: July

By July, most adult Lesser Black-backed Gulls are very busy feeding the now fledged young. By mid-July large flocks of 100's of 1cy birds leave the colonies simultaneously and gather on the sandy beaches. The adults keep on feeding the 1cy birds on these beaches, often until the end of the month.
The moult score on adult LBBG may be influenced by the energy and effort which is put in the feeding of chicks. In the colony, we try to score primary and wing-covert moult in relation with number of eggs or fledged chicks. Year 2002 we didn't collect enough data on this subject. However, we can represent figures of primary moult in adult LBBG which still have a strong bond with the colony. They arrive at a nearby sandy beach to drink, wash and preen quickly, leaving again within 10 minutes to fly back into the colony. Primary moult score is presented in the next table.

Tables & Graph

starting date:	25 Jun	02 Jul	09 Jul	30 Jul	06 Aug
week no:	26	27	28	31	32
REM 0	0	0	0	0	0
REM 1	0	0	0	0	0
REM 2	0	0	0	0	0
REM 3	0	0	0	0	0
REM 4	0	0	0	4	0
REM 5	0	0	0	7	1
REM 6	0	1	0	13	12
REM 7	0	14	10	16	6
REM 8	0	64	53	13	3
REM 9	1	112	84	1	3
REM 10	5	127	140	10	1
	0	0	0	0
n =	6	318	287	64	26
average P =	9.8	9.1	9.2	7.1	6.9
95% CID =	0.43	0.10	0.10	0.43	0.51
inverse =	2.57	1.97	1.97	2.00	2.06
Variantie (s²) =	0.17	0.80	0.76	2.91	1.59
SD (s) =	0.41	0.89	0.87	1.71	1.26
SE (s_x) =	0.17	0.05	0.05	0.21	0.25

% class:
0	0	0	0	0	0
1	0	0	0	0	0
2	0	0	0	0	0
3	0	0	0	0	0
4	0	0	0	6	0
5	0	0	0	11	4
6	0	0	0	20	46
7	0	4	3	25	23
8	0	20	18	20	12
9	17	35	29	2	12
10	83	40	49	16	4

% control:	100	100	100	100	100

Table above, data for the Netherlands (2000-2010), results for July (aggregated week): number of remaining old primaries in adults.
REM10 = 10 primaries still old (hence, complete moult not started yet).

Above: Scatter Plot for PMS in adult Lesser Black-backed Gulls. Number of remaining old primaries throughout the year (arrested moult excluded). Sample size is 6.171 birds.

Above: Scatter Plot for PMS in adult Lesser Black-backed Gulls. Number of remaining old primaries for July (arrested moult excluded). Sample size for this graph is 302 ringed birds + 399 unringed birds.

starting date:	04 Jun	02 Jul	09 Jul	13 Aug
week no:	23	27	28	33
NEW 0	8	1	115	3
NEW P1	0	1	6	2
NEW P2	0	0	0	6
NEW P3	0	0	0	7
NEW P4	0	0	0	8
NEW P5	0	0	0	1
NEW P6	0	0	0	0
NEW P7	0	0	0	0
NEW P8	0	0	0	0
NEW P9	0	0	0	0
NEW P10	0

n =	8	2	121	27
average NEW P =	0.0	0.5	0.0	2.7
95% CID =	0.00	6.35	0.04	0.55
inverse =	2.36	12.71	1.98	2.06
Variantie (s²) =	0.00	0.50	0.05	1.92
SD (s) =	0.00	0.71	0.22	1.39
SE (s_x) =	0.00	0.50	0.02	0.27

% class
0	100	50	95	11
1	0	50	5	7
2	0	0	0	22
3	0	0	0	26
4	0	0	0	30
5	0	0	0	4
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

Table above, data for the Netherlands (2000-2010), results for July (aggregated week): number of new, fully grown primaries in adults.
NEW0 = no new primaries visible (arrested moult excluded in this analysis). So either P1 still old, or P1 dropped, but the very tip still not visible.
NEW1 = P1 longest new primary. Range between "at least the tip of P1 is visible" until "tip of P2 still shorter than P1".
NEW2 = P2 longest new primary. NEW3 = etc.

Above: Scatter Plot for PMS in adult Lesser Black-backed Gulls throughout the year. Longest new primary is classified "fully grown". Sample size is 2.969 birds. Birds scored on NEW primaries (arrested moult excluded).

Above: Scatter Plot for PMS in adult Lesser Black-backed Gulls. Scoring on longest new primary, which is classified "fully grown" for July (arrested moult excluded). Sample size for this graph is 2 ringed birds + 121 unringed birds.

The earliest date for birds with missing primaries is 30 April 2006, which is not the earliest day in our complete sample. We scored 98 Lesser Black-backed Gulls prior to that date, some already in February. As can be expected, none of these was in primary moult, and this group was excluded in our further analysis as it will only result in a misfit for the onset of moult, using linear regression statistics.

The last scoring days were in November, with a larger sample (133 adults) on 04 November 2010. From that date we have the last birds with retaining old primaries (13 birds with 1, 2 or even 3 old primaries; 120 birds with no old primaries left). From other days in November, only 10 birds were scored (all ringed adults). They all had no old primaries left.

The first tine a new primary (P1) was visible, was on 08 May 2006. Prior to this date, birds were scored missing inner primaries, but the very tip was still not visible (and therefore not scored). As soon as the tip of P1 was visible, this was automatically scored "fully grown" 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).

Peter Stewart presents onset of primary moult by scores for caught adult Lesser Black-backed Gulls in the Severn Estuary, U.K., repeated in the table below. To read his results, see this PDF file.

Table: the number of old remaining primaries present. Compare PMS of adult graellsii at half monthly intervals. Data from the Severn Estuary Gull Group by Peter Stewart: The primary moult of the Lesser Black-backed Gull (special publication No 1). Scores in the Netherlands can be influenced by unringed nominate fuscus, in autumn in particular.
	Netherlands			Severn Estuary U.K.
	PMS range	N:	Average PMS	PMS range	N:	Average PMS
1-15 apr	10	49	10	8-10	216	9,9
16-30 apr	10	47	10	10	197	10,0
1-15 may	8-10	849	9,8	8-10	167	9,9
16-31 may	7-10	380	9,7	7-10	76	9,5
1-15 jun	8-10	104	9,6	7-10	33	8,6
16-30 jun	7-10	253	9,7	6-10	65	8,2
1-15 jul	6-10	605	9,2	5-10	176	7,4
16-31 jul	-	-	-	4-8	44	6,4
1-15 aug	3-10	143	6,6	3-10	165	5,2
16-31 aug	2-10	1284	5,4	3-8	127	4,6
1-15 sep	1-10	300	3,6	0-7	234	3,3
16-30 sep	0-7	645	2,9	0-7	173	2,1
1-15 oct	0-9	733	2,2	0-4	328	0,9
16-31 oct	0-10	750	1,3	0-3	244	0,3
1-15 nov	0-3	138	0,2	0-3	604	0,1
16-30 nov	0	5	0	0-1	341	0,0

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 = 6171, R2= 0.820, sign: P<0,000)
PMS = -0,381* WEEK + 17,967

Ringed adults: Linear regression (n = 2069, R2= 0.800, sign: P<0,000)
PMS = -0,325* WEEK + 16,270

Unringed adult: Linear regression (n = 4102, R2= 0.779, sign: P<0,000)
PMS = -0,513* WEEK + 23,031

LINEAR REGRESSION FOR NEW FULLY GROWN PRIMARIES

Complete sample: Linear regression (n = 2969, R2= 0.930, sign: P<0,000)
PMS = 0,302* WEEK - 5,933

Ringed adults: Linear regression (n = 1209, R2= 0.888, sign: P<0,000)
PMS = 0,252* WEEK - 4,747

Unringed adult: Linear regression (n = 1760, R2= 0.833, sign: P<0,000)
PMS = 0,442* WEEK - 11,906

Primary moult score of adult LBBG at Maasvlakte, the Netherlands, July.
	Missouriweg 13.07.02	Dintelhaven 14.07.02
0 missing:	34	62
P1 missing:	27	39
P2 missing:	14	18⁽¹⁾
P3 missing:	2	2
P4 missing:	0	0
n:	77	121
(1): Five birds had P2 missing and P1 growing. Missouriweg: aggregate score from location Nachtegalenkeet & Missouriweg - Maasvlakte, the Netherlands (51.57N,04.03E). Dintelhaven: score from location Dintelhaven - Maasvlakte, the Netherlands (51.57N,04.03E). See Maasvlakte map.

Some details about colour rings (CRs)

Late June, early July are the weeks to catch pulls and colour ring them. This has been done for years now at Maasvlakte, the Netherlands and most images show ringed adults from these projects. Ring projects are going on for decades already and in Vest-Agder, S Norway, over 60.000 LBBGs have been ringed throughout the years. From 1995 on, blue colour ringed LBBGs from Scandinavia turn up. Some details:

species:	intermedius	intermedius	intermedius	fuscus	fuscus
age:	1cy	5cy+	Pull	1cy	Pull
total:	1	81	4390	1	10
<>	.	.		.	.
1985	.	.	2	.	.
1986	.	.	1	.	.
1988	.	.		.	.
1989	.	.	1	.	.
1991	.	.	4	.	.
1993	.	.	1	.	.
1995	.	.	84	.	.
1996	.	.	117	.	.
1997	.	.	726	.	.
1998	.	.	439	.	.
1999	.	19	843	.	.
2000	1	3	454	1	10
2001	.	59	1718	.	.

At Westkapelle, the Netherlands (see distribution), LBBGs can be found well into November. Readings of (metal) ringed LBBGs revealed some originate from Denmark, some from Sweden and some from S Norway. Although local Dutch individuals may occur as well, bulk of the present LBBGs in November are probably Scandinavian birds. Large colonies can be found in Vest Agder (S Norway) and this is the most northern colony from which ringed Scandinavian birds occur in the Netherlands.

But though they may be seen in NW Europe well into November, others (from the same colony) proved to be more adventurous. For instance this known long distance migrant, much in line with Finnish colour-ringed LBBG fuscus. It's a 1cy LBBG X, metal ringed Stavanger 472418 date July 5 1984 at Rauna, Farsund, Vest-Agder, Norway 58.03N 06.40E and shot October 18 1984 in Owando, Kongo 00.27S 15.44E, 6553 km to the south 3 months and 13 days later.
Colour-ringed birds from the Maasvlakte have been reported to migrate over long distances as well: they were seen at interesting location e.g. USA and Finland.

In the Ring Recovery Section, we try to plot the races of Larus fuscus to give more detials on the various migration routes.

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adult LBBG UK.: graellsii.
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Lesser Black-backed Gull graellsii 1N8B adult, July 27 2013, Calais, NW France. Picture: Jean-Michel Sauvage.
Ringed as adult in winter.

Lesser Black-backed Gull graellsii 2.K4 adult, July - October 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.

Lesser Black-backed Gull graellsii 5SF 6CY, July 26 2016, Praia de Mira, Coimbra, Portugal. Picture: José Marques.

Lesser Black-backed Gull graellsii FH5T adult, July 20 2016, Utrecht, the Netherlands.

Lesser Black-backed Gull graellsii BTO GG49760 19cy & 21cy, 2012 & 2014, Calais, NW France. Picture: Jean-Michel Sauvage.

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adult LBBG France: graellsii.
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Lesser Black-backed Gull graellsii 028A 5cy-6cy, July 06 2014, Calais, NW France. Picture: Jean-Michel Sauvage. Also August 2013, when showing arrested moult.

Lesser Black-backed Gull graellsii 029A 5cy, May 18 & July 04 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA677766 / 077A 9CY, July 14 2017, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 142N 6cy, July 27 2010, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA639885 / 165N 8cy, April 15-24 2011 & July 18 2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA670004 / 169N 6cy & 9cy, July 2010 & March 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA639851 / 192N 8cy, August 2009, April & July 2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 280N 7cy, July 18 2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 331K 7cy, July 29 2014, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 359N 2cy, 6cy-9cy, April 2011-2014, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 589N 7cy, July 12 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA672380 / 593N 11CY, May - July 2017, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 600N 4cy-6cy, 2010-2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 718N 6cy, July 04 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA676223 / 826N 5cy, July 17 2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 883N 6cy, April & July 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii FRP EA672456 / 937K adult, May - July 2017, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 963N 4cy-5cy, May 2011 & April 2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 989N 5CY, 8CY-9CY, 2010, 2013 & 2014, Calais, NW France. Picture: Jean-Michel Sauvage.

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adult LBBG Belgium: graellsii Dutch intergrade.
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Lesser Black-backed Gull graellsii AWAV 17CY, July 25 2015, Neeltje Jans, the Netherlands.

Lesser Black-backed Gull graellsii DWAH 5CY, July 31 2010, Neeltje Jans, the Netherlands. Female.

Lesser Black-backed Gull graellsii GRAR 5cy & 7cy, July 03 2010, Heemskerk, the Netherlands. Female.

Lesser Black-backed Gull graellsii HCAA 7cy, July 05 2014, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii HKAB 5cy, 2012 & 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii KJAM 7CY-11CY, 2013-2017, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii NHAH 4cy, July 20 2013, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii UK.AB 3CY & 5CY, June 2014 & July 2016, Boulogne-sur-Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii BLB L-63883 11cy, July 29 2011, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii BLB L-103216 9CY, July 29 2010, Neeltje Jans, the Netherlands.

Lesser Black-backed Gull graellsii BLB L906179 6cy-8cy, 2010-2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii BLB L-909103 adult, July 27 2010, Neeltje Jans, the Netherlands.
Ringed as adult in Belgium.

Lesser Black-backed Gull graellsii BLB L-910478 adult, July 31 2010, Neeltje Jans, the Netherlands.
Ringed as adult in Belgium.

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adult LBBG the Netherlands: graellsii Dutch intergrade.
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Lesser Black-backed Gull graellsii Y.AST adult, August 2014 & July 2016, Boulogne sur mer, NW France & IJmuiden, the Netherlands. Picture: Jean-Michel Sauvage & Mars Muusse.

Lesser Black-backed Gull graellsii Y.CBA adult, July 18 2016, IJmuiden, the Netherlands.

Lesser Black-backed Gull graellsii FADZ 8+CY, July 16 2011, Texel, the Netherlands. Ringed as breeding female.

Lesser Black-backed Gull graellsii MAAJ adult, July 25 2010, Texel, the Netherlands.

Lesser Black-backed Gull graellsii MABH adult, July 22 2012, Texel, the Netherlands.

Lesser Black-backed Gull graellsii OV 6cy-8cy, 2010-2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii 5J adult, July 31 2015, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii 79 adult, 2005, 2013 & 2014, Dordrecht & Moerdijk, the Netherlands. Picture: Merijn Loeve & Muusse brothers.

Lesser Black-backed Gull graellsii NN adult, May 2006 & July 2015, Moerdijk & Tilburg, the Netherlands. Picture: Merijn Loeve & Mars Muusse.

Lesser Black-backed Gull graellsii DJ 8CY-9CY & 11CY, 2014-2015 & 2017, Maasvlakte & Utrecht, the Netherlands. Picture: Merijn Loeve, Herman Bouman & Mars Muusse.

Lesser Black-backed Gull graellsii CX adult, July 27 2015, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii EK adult, June-July 2015, Rotterdam & Tilburg waste dump, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii H= adult, July 27 2015, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii JX adult, July 27 2015, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii KF adult, July 27 2015, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii 0M July 27 2010, Neeltje Jans, the Netherlands.

Lesser Black-backed Gull graellsii 0N July 21 2010, Neeltje Jans, the Netherlands.

Lesser Black-backed Gull graellsii P.3 5CY, June-July 2017, Katwijk, the Netherlands.

Lesser Black-backed Gull graellsii 3D 6CY, July 31 2015, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii CY 7CY, July 05 2014, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii GN adult, July 16 2012, Utrecht, the Netherlands. Picture: Herman Bouman.

Lesser Black-backed Gull graellsii M= adult, March & July 2015, Maasvlakte, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii R3 7CY, July 16 2015, Tilburg, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii U7 5CY, May & July 2015, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii UG adult, July 08 2014, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull (graellsii) 2N 5CY, June - July 2016, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii AU adult, July 27 2015, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii C+ adult, July 2015 & May 2018, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve & Mars Muusse.

Lesser Black-backed Gull graellsii C0 adult, July 27 2015, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii C9 adult, July 27 2015, Maasvlakte - Europoort, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii E B59 14CY, July 03 2015, Gouda, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii P adult, July 07 2001, IJmuiden, the Netherlands.
Ringed at IJmuiden, white left double black top and red right P.

Lesser Black-backed Gull graellsii adult, July 07 2001, IJmuiden, the Netherlands. Ringed at IJmuiden.

Lesser Black-backed Gull graellsii T adult, July 7 2001, IJmuiden, the Netherlands. Ringed at IJmuiden, white left triple black bar and red right T.

Lesser Black-backed Gull graellsii S 13CY, July 08 2014, Maasvlakte, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii TN1 12cy, July 21 2009, Barneveld, The Netherlands. Picture: Herman Bouman.

Lesser Black-backed Gull graellsii N129 adult, July 14 2002, Papegaaienbek, Maasvlakte, the Netherlands.

Lesser Black-backed Gull graellsii TB5T adult, July 08 2015, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii VH3T adult, July 20 2015, Rotterdam, the Netherlands. Picture: Merijn Loeve.

Lesser Black-backed Gull graellsii EM30 9cy, July 13 2004, Missouriweg, Maasvlakte, the Netherlands.
Ringed as pullus July 10 1996.

Lesser Black-backed Gull graellsii AS2 11cy, July 14 2002, Papegaaienbek, Maasvlakte, the Netherlands.
Ringed as pullus on June 20 1992.

Lesser Black-backed Gull graellsii EK3 9cy, July 06 2001, IJmuiden, the Netherlands.
Ringed on June 21 1993 at Maasvlakte.

Lesser Black-backed Gull graellsii PC7 5cy, July 06 2001, IJmuiden, the Netherlands.
Ringed on July 01 1997 at Maasvlakte.

Lesser Black-backed Gull graellsii PP4 6cy, July 14 2002, Dintelhaven, Maasvlakte, the Netherlands.
P1 is still present. Ringed as pullus on June 28 1997.

Lesser Black-backed Gull graellsii SR6 5cy, July 07 2001, IJmuiden, the Netherlands.
Ringed on July 01 1997 at Maasvlakte.

Lesser Black-backed Gull graellsii SY6 / NJ 17CY & 19CY, May-July 2013 and May 2015, Katwijk, the Netherlands.

Lesser Black-backed Gull graellsii TU5 19CY, July 25 2015, Neeltje Jans, the Netherlands.

Lesser Black-backed Gull graellsii TV4 adult, July 14 2002, Dintelhaven, Maasvlakte, the Netherlands.
P1 is still present.

Lesser Black-backed Gull graellsii E495 8cy, July 14 2002, Dintelhaven, Maasvlakte, the Netherlands.
Ringed as pullus on June 29 1995.

Lesser Black-backed Gull graellsii EAH9 6cy, July 14 2002, Dintelhaven, Maasvlakte, the Netherlands. P3 has been shed.
Ringed as pullus on June 24 1997.

Lesser Black-backed Gull graellsii NLA 5.412.028 adult, July 31 2010, Leiden, the Netherlands.

Lesser Black-backed Gull graellsii NLA 5.421.834 6cy, July 17 2012, Calais, NW France. Picture: Jean-Michel Sauvage.

Lesser Black-backed Gull graellsii NLA 5.331.913 5CY, July 14 2002, Papegaaienbek, Maasvlakte, the Netherlands.

Lesser Black-backed Gull graellsii NLA 5.293.8?? adult, July 14 2002, Dintelhaven, Maasvlakte, the Netherlands.
P1 and P2 have been shed.

Lesser Black-backed Gull graellsii F032 adult, July 21 2015, Alphen aan de Rijn, the Netherlands. Picture: Merijn Loeve.

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adult LBBG Norway: intermedius.
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Lesser Black-backed Gull intermedius J2TM 2CY - 5CY, January 2012 - July 2016, Norway and The Gambia.

Bird with primary moult in its 1st winter.

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unringed adult LBBG: all most likely graellsii birds, when photographed in the Netherlands.
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Lesser Black-backed Gull adult, July 18 2013, Katwijk, the Netherlands.
P1-P10 present.

Lesser Black-backed Gull adult, July 18 2013, Katwijk, the Netherlands.
P1/P3.

Lesser Black-backed Gull adult, July 18 2013, Katwijk, the Netherlands.
P1/P4.

Lesser Black-backed Gull adult, July 18 2013, Katwijk, the Netherlands.
P2/P5.