Lesser Black-backed Gull (graellsii & intermedius)

(last update: 14-11-2017 )

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lbbg 1cy August
lbbg 1cy September
lbbg 1cy October
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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 October

Movements

By October, all LBBG have left the colonies and surrounding feeding grounds near the Maasvlakte (the Netherlands) and migrate south towards France, Portugal and Morocco. In November and to a lesser extend December, a couple of hundreds remain on continental NW Europe, as north as the south of the Netherlands along the coast at Westkapelle, 65 km south of the Maasvlakte (see map). As it seems, every year a larger group of LBBGs stay "at the most northern latitude as possible", i.e. migrate south only when winter conditions force them to.

By late November 2000 (a rather mild winter) ringed individuals from Scandinavia, Denmark, the Netherlands, Belgium and the U.K. were present at Westkapelle. When winter really started in December 2000, this group moved south as well to unknown wintering grounds, probably the Atlantic coast of West and South-West Europe. 

Lesser Black-backed Gull adult, October 13 2015, Katwijk, the Netherlands.

Lesser Black-backed Gull adult, October 29 2015, Katwijk, the Netherlands.

Lesser Black-backed Gull adult, October 29 2015, Katwijk, the Netherlands.

Lesser Black-backed Gull adult, October 08 2015, Katwijk, the Netherlands.

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. 

Tables & Graph

starting date:   24 Sep   01 Oct   08 Oct   15 Oct   22 Oct   29 Oct   05 Nov
week no: 39 40 41 42 43 44 45
REM 0 0 2 97 111 113 122 2
REM 1 19 1 183 165 56 3 0
REM 2 85 2 217 175 55 9 0
REM 3 123 2 106 38 7 1 0
REM 4 44 0 39 11 2 0 0
REM 5 24 0 28 7 1 0 0
REM 6 9 0 29 5 0 0 0
REM 7 5 0 8 3 0 0 0
REM 8 1 0 9 1 0 0 0
REM 9 0 0 3 1 0 0 0
REM 10 0 0 3 1 0 0 0
0 0 0 0 0 0 0
n = 310 7 722 518 234 135 2
average P = 3.1 1.6 2.2 1.5 0.9 0.2 0.0
95% CID = 0.14 1.18 0.13 0.12 0.13 0.10 0.00
inverse = 1.97 2.45 1.96 1.96 1.97 1.98 12.71
Variantie (s2) = 1.57 1.62 3.30 1.81 0.97 0.33 0.00
SD (s) = 1.25 1.27 1.82 1.35 0.98 0.57 0.00
SE (sx) = 0.07 0.48 0.07 0.06 0.06 0.05 0.00
               
% class:              
0 0 29 13 21 48 90 100
1 6 14 25 32 24 2 0
2 27 29 30 34 24 7 0
3 40 29 15 7 3 1 0
4 14 0 5 2 1 0 0
5 8 0 4 1 0 0 0
6 3 0 4 1 0 0 0
7 2 0 1 1 0 0 0
8 0 0 1 0 0 0 0
9 0 0 0 0 0 0 0
10 0 0 0 0 0 0 0
               
  % control: 100 100 100 100 100 100 100

  Table above, data for the Netherlands (2000-2010), results for October (aggregated week): number of remaining old primaries in adults.
REM0 = 0 old primaries left (P10 dropped).

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 October (arrested moult excluded). Sample size for this graph is 40 ringed birds + 1888 unringed birds.

starting date:

24 Sep

08 Oct

15 Oct

22 Oct

29 Oct

05 Nov

week no:

39

41

42

43

44

45

NEW 0

0

0

0

0

0

0

NEW P1

0

0

0

0

0

0

NEW P2

0

0

0

0

0

0

NEW P3

0

0

0

0

1

1

NEW P4

4

0

0

2

1

1

NEW P5

10

1

2

17

5

6

NEW P6

4

12

94

62

10

13

NEW P7

0

5

127

162

96

115

NEW P8

0

0

24

136

164

145

NEW P9

0

0

0

0

71

18

NEW P10

 

 

 

 

2

13

 

 

 

 

 

 

 

n =

18

18

247

379

350

312

average NEW P =

5.0

6.2

6.7

7.1

7.8

7.6

95% CID =

0.34

0.27

0.08

0.09

0.10

0.11

inverse  =

2.11

2.11

1.97

1.97

1.97

1.97

Variantie (s2) =

0.47

0.30

0.42

0.74

0.83

0.91

SD (s) =

0.69

0.55

0.65

0.86

0.91

0.95

SE (sx) =

0.16

0.13

0.04

0.04

0.05

0.05

 

 

 

 

 

 

 

% class

 

 

 

 

 

 

0

0

0

0

0

0

0

1

0

0

0

0

0

0

2

0

0

0

0

0

0

3

0

0

0

0

0

0

4

22

0

0

1

0

0

5

56

6

1

4

1

2

6

22

67

38

16

3

4

7

0

28

51

43

27

37

8

0

0

10

36

47

46

9

0

0

0

0

20

6

10

0

0

0

0

1

4

 

 

 

 

 

 

 

% control:

100

100

100

100

100

100

 

  Table above, data for the Netherlands (2000-2010), results for October (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 October (arrested moult excluded). Sample size for this graph is 58 ringed birds + 1266 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

Oct 8-12: Remaining old primaries for adult LBBG year 2001 (the Netherlands)
. 0 1 2 3 4 5 6 7 8 9 10 n: m:
  101 136 173 83 30 22 25 7 8 3 3 591 2,17
(aggregated Maasvlakte & Westkapelle) n: total; m: average

 

Adult LBBG primary scores, Naaktstrand - Maasvlakte, the Netherlands, October 19 2002
. p8 old p9 old p10 old no old total old
p5 f.g. 2 - - - 2
p6 f.g. 3 68 20 - 91
p7 f.g. - 19 60 39 118
p8 f.g. - - 2 22 24
total f.g. 5 87 82 61 235

Notes:
1. f.g. (fully grown): including primaries which are not completely fully grown, but all primaries of which the tip exceeds the previous primary in the folded wing.
2. old primaries: total (n) = 235, average (m) = 8,8 standard deviation (SD) = 0,86.
3. new primaries: total (n) = 235, average (m) = 6,7 standard deviation (SD) = 0,66.
4.Adult LBBG scored in a group of 1.500 birds (of which 90% LBBG). A remarkable homogeneous group regarding grey-tone of upper-parts, after three days of western winds.
5. a few ringed birds in this group: 
orange CA9 (P10 old, P7 f.g.) ringed as pullus in the Netherlands on July 01 1995, now 8cy.
green EA34 (P10 old, P7 f.g.) ringed as pullus in the Netherlands on July 02 1993, now 10cy.
green EV62 (P10 old, P7 f.g.) ringed as pullus in the Netherlands on June 21 1997, now 6cy.

 

Adult LBBG primary scores, Dannes (region Calais), NW France, October 19 2002
. p6 old p7 old p8 old p9 old p10 old no old total old
p4 f.g. - 1 - - - - 1
p5 f.g. 1 1 5 1 - - 8
p6 f.g. - - 2 30 11 - 43
p7 f.g. - - - 23 37 30 90
p8 f.g. - - - 1 8 83 92
total f.g. 1 2 7 55 56 113 234

Notes:
1. f.g. (fully grown): including primaries which are not completely fully grown, but all primaries of which the tip exceeds the previous primary in the folded wing.
2. old primaries: total (n) = 234, average (m) = 9,1 standard deviation (SD) = 0,98.
3. new primaries: total (n) = 234, average (m) = 7,1 standard deviation (SD) = 0,86.
4.Adult LBBG scored in a group of 2.000 birds (of which 30% LBBG). A heterogeneous group regarding grey-tone of upper-parts.
5. a few ringed birds in this group: 
orange EV89 (P8 f.g.) ringed as pullus in the Netherlands on July 02 1997, now 6cy.
green E774 (P9 = P8 f.g.) ringed as pullus in the Netherlands on July 04 1995, now 8cy.
white R23 (P9 old, P6 f.g.) ringed as pullus in the Netherlands on July 06 1991, now 12cy.
blue ASAY (P8 f.g.) ringed in Belgium.
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Iceland: 'graellsii'
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Lesser Black-backed Gull graellsii Y250 adult, September - December 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
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Britain: 'graellsii'
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ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 0AS 19CY, October 23 2015, Praia da Aguda, V.N.Gaia, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 0.V7 7CY-8CY, September - October 2015, September - November 2016, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 2.K4 adult, October 16 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 6.C7 7CY, October 25 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 0AT7 adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 0FA1 adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 1AH4 adult, October 31 2016, Espinho Beach, Espinho, Aveiro, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 1AV8 5CY, September - October 2017, Leixões harbour, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 1AZ1 adult, October 25 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 1CJ2 adult, October 20 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 1FA1 adult, October - November 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 2AK8 adult, October 27 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 2CT8 3CY-5CY, September 2015 - October 2017, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 3AL2 adult, October 2015, September 2016 - January 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 3AP7 5CY, October - November 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gullgraellsii 3AU9 adult, October 31 2016, Espinho Beach, Espinho, Aveiro, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 3AX9 adult, October - November 2016, Espinho Beach, Espinho, Aveiro, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 3CH9 adult, October 06 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 3CT2 adult, September - October 2016 & 2017, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 4AF8 adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 4AX5 adult, October - December 2015, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 4CN0 2CY-4CY, March 2015 - October 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 5CC4 adult, September -October 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 5CT1 adult, September - October 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 5FA2 adult, October 06 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 6AN1 5CY, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 6CA8 adult, January & October 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 6CF6 adult, October 2015, September 2016 - February 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 6CH4 adult, September - October 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 8AK3 adult, October - November 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 8AM2 adult, October 20 2015, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 8CL6 adult, October 20 2015, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 8CS1 adult, September - November 2016, Leixões harbour, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 8AC0 adult, October 2015 & November 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 9AH6 adult, September - December 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 9AT6 adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 9AX4 adult, October 2015 & November 2016, Torreira beach, Aveiro, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 9CF6 adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the U.K. (153884 bytes)Lesser Black-backed Gull graellsii 9CJ0 adult, October 26 2014, Landfill VRSU de Colmenar Viejo, Madrid, Spain. Picture: Delfín González.
ad LBBG in October, ringed in the U.K. (153884 bytes)Lesser Black-backed Gull graellsii APF adult, October 21 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
ad LBBG in October, ringed in the U.K. (57532 bytes)Lesser Black-backed Gull graellsii ATN adult, October 22 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
ad LBBG in October, ringed in the U.K. (61530 bytes)Lesser Black-backed Gull graellsii LSY 6CY, October 22 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
ad LBBG in October, ringed in the U.K. (115719 bytes)Lesser Black-backed Gull graellsii YLS adult, October 19 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii F:Z 11CY, October - November 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii B:V 14CY-15CY, September 2015 & October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii F+P 8CY, October 11 2016, Leça Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii T:87J adult, October - December 2016, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 9H:W adult, October 16 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 5JG adult, September - October 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 6SF 5CY & 7CY, October 2015 & February 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 4.Z3 8CY-9CY, October- December 2015 & September - November 2016, Torreira beach, Beira Litoral, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii JZ adult, October 09 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the U.K. (122109 bytes)Lesser Black-backed Gull graellsii BTO GG 63238 16CY, Westkapelle, the Netherlands, October 04 2004. Photo by Pim Wolf.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii BTO GG 86885 25CY, October 09-20 2015, Leixões Harbour, Matosinhos, Portugal. Picture: José Marques.
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Spain: 'graellsii'
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Lesser Black-backed Gull graellsii ZMAC 14CY, October 06 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
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France: 'Dutch intergrade'
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Lesser Black-backed Gull graellsii 188K 10CY, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 912K adult, October 09 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 3:AAA adult, October 07 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii R:K9E adult, October 09 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii R:E1J adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii R:C6V adult, September - October 2016, Leixões Harbour, Matosinhos, Portugal. Picture: José Marques.
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Belgium: 'Dutch intergrade'
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Lesser Black-backed Gull graellsii A.L0H adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii DAA.Z adult, October 31 2016, Espinho Beach, Espinho, Aveiro, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes) Lesser Black-backed Gull graellsii D.FAY adult, October 01 2009, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii DKAN 15CY, 17CY, October 2009 & September 2011, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii GHAR 7CY, October 31 2013, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii GT.AM adult, October 20 2015, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes) Lesser Black-backed Gull graellsii LC.AS adult, October 27 2010, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes) Lesser Black-backed Gull graellsii L.DAN adult, October 06 2009, Westkapelle, the Netherlands.
ad LBBG in October, ringed in Belgium. (74645 bytes)Lesser Black-backed Gull graellsii BLB L - 7400? adult, October 05 2002, Le Portel / Boulogne-sur-Mer, NW France.
ad LBBG in October, ringed in Belgium. (85453 bytes)Lesser Black-backed Gull graellsii BLB L - 80954 5CY, October 22 2001, Westkapelle, the Netherlands.
ad LBBG in October, ringed in Belgium. (75750 bytes)Lesser Black-backed Gull graellsii BLB L - 85168 5CY, October 30 2003, Westkapelle, the Netherlands.
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the Netherlands: ' Dutch intergrade'
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Lesser Black-backed Gull graellsii G||S adult, October 07 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull graellsii H5 adult, May 2006, October 2011 & August 2016, the Netherlands. Picture: Theo Muusse, Maarten van Kleinwee & Henri Zomer.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii 6K adult, September 2015 & December 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii LY adult, October 2015 - February 2016 & November 2016 - January 2017, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii UJ adult, October 07 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii WD adult, October 06 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 2.G 5CY, October 07 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii GX adult, October - November 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii CY 7CY-9CY, July 2014 & October 2015 - November 2016, NW France & Portugal. Picture: Jean-Michel Sauvage & José Marques.
Lesser Black-backed Gull graellsii YZ 7CY, October 06 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii RD adult, October 11 2010, Madrid, Spain. Photo by Delfín González.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii R.7 adult, October 09 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii WE adult, October 11 2010, Madrid, Spain. Photo by Delfín González.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii HF adult, October 11 2010, Madrid, Spain. Photo by Delfín González.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii PU 9CY, October 16 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull graellsii P8 adult, October 27 2006, Westkapelle, the Netherlands.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii 6L adult, October 08 2014 & May 2006, the Netherlands & France. Picture: Jean-Michel Sauvage.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii HL adult, May 2015 & October 2016, Moerdijk & Katwijk, the Netherlands.
Lesser Black-backed Gull graellsii T2 adult, May 2005, May 2006 & October 2016, the Netherlands & Portugal. Picture: Mars Muusse & José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii K.AWV 5CY, October 25 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii K.AZX 2CY-5CY, August 2014 - October 2017, the Netherlands & Portugal. Picture: Maarten van Kleinwee & José Marques.
2275.jpg (40492 bytes)Lesser Black-backed Gull graellsii KLAX 6CY, October 21 2012, Spain. Also as 4cy in Holland.
Lesser Black-backed Gull graellsii K.YAY 8CY, October 10 2016, Leixões harbour, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii YAHJ adult, 2009-2011, France & the Netherlands. Pictures: Ruud Altenburg & Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80494 bytes)Lesser Black-backed Gull graellsii YAKZ adult, 2010-2011, IJmuiden-Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (77525 bytes)Lesser Black-backed Gull graellsii Y.AWC 3CY & 5CY, June 2013 & October 2015, the Netherlands. Picture: Maarten van Kleinwee & Merijn Loeve.
Lesser Black-backed Gull graellsii Y.BAC adult, September - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii Y.BJS adult, October 31 2016, Espinho Beach, Espinho, Aveiro, Portugal. Picture: José Marques.
ad LBBG in October, ringed in the Netherlands. (77525 bytes)Lesser Black-backed Gull graellsii E864 15CY, October 06 2009, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (77525 bytes)Lesser Black-backed Gull graellsii ECJ9 5CY, October 14 2001, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (85975 bytes)Lesser Black-backed Gull graellsii EN22 9CY, October 19 2004, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (86535 bytes)Lesser Black-backed Gull graellsii JP2 11CY, October 11 2003, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii JR6 16CY, October 19 2008, Madrid, Spain. Photo by Delfín González.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii KN8 11CY, October 03 2003, Scheveningen, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (65112 bytes)Lesser Black-backed Gull graellsii E737 10CY, October 04 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
ad LBBG in October, ringed in the Netherlands. (67338 bytes)Lesser Black-backed Gull graellsii EL74 8CY, October 11 2003, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (73481 bytes)Lesser Black-backed Gull graellsii ECK1 6CY, October 03 2002, Boulogne-sur-Mer, NW France.
ad LBBG in October, ringed in the Netherlands. Lesser Black-backed Gull graellsii EH10 6CY, Westkapelle, the Netherlands, October 21 1999. Photo by Pim Wolf. Born summer 1994 in the Netherlands.
ad LBBG in October, ringed in the Netherlands. Lesser Black-backed Gull graellsii ER73 7+CY, Westkapelle, the Netherlands, October 15 & 27 1999. Photo by Pim Wolf.
ad LBBG in October, ringed in the Netherlands. (125356 bytes)Lesser Black-backed Gull graellsii E214 5CY, October 04-07 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
ad LBBG in October, ringed in the Netherlands. (142636 bytes)Lesser Black-backed Gull graellsii E219 5CY, October 01 2004, Westkapelle, the Netherlands. Picture Pim Wolf. Also seen as 2cy at Westkapelle.
ad LBBG in October, ringed in the Netherlands. (142636 bytes)Lesser Black-backed Gull graellsii 7F 5CY, October 09 2010, Heemskerk, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (86318 bytes)Lesser Black-backed Gull graellsii NLA 5.362.926 adult, October 13 2001, Westkapelle, the Netherlands.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull graellsii NLA 5.366.905 adult, October 09 2005, Westkapelle, the Netherlands.
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N Germany: transition graellsii - intermedius
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2cy intermedius in October, ringed in Norway. (97235 bytes) Lesser Black-backed Gull graellsii H.501 3cy-5cy, 2009-2010, Leiden, the Netherlands. Pictures Maarten van Kleinwee. From N Germany, the overlap zone of graellsii "Dutch intergrade" and intermedius.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii H.L84 adult, October 10 2016, Katwijk, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull graellsii HXE2 adult, October 16 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
juvenile LBBG, ringed in the Netherlands. Lesser Black-backed Gull graellsii HT08 adult, October 03 2016, Katwijk, the Netherlands.
ad LBBG in winter, ringed in the Netherlands. (65647 bytes)Lesser Black-backed Gull graellsii DEH 4290815 7cy, October 03 2012, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
.Denmark: intermedius
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Lesser Black-backed Gull intermedius V3PJ 3CY & 9CY, September 2010 & October 2016, the Netherlands & Portugal. Picture: Maarten van Kleinwee & José Marques.
2cy intermedius in July, ringed in Norway. (114585 bytes)Lesser Black-backed Gull intermediusV3SJ 2CY & 6CY, July 2010, August 2014 & October 2014, Utrecht, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Lesser Black-backed Gull intermedius V.231 8CY, October 13 2015, Leixões Harbour, Matosinhos, Portugal. Picture: José Marques.
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)Lesser Black-backed Gull intermedius VC5M adult, June & September 2010 & October 2012, Denmark, the Netherlands, Spain.
Lesser Black-backed Gull intermedius V.JA7 adult, October 06 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
adult intermedius in October, ringed in Denmark. (83054 bytes)Lesser Black-backed Gull intermedius DKC 467213 9cy, October 14 2001, Westkapelle, the Netherlands.
adult intermedius in October, ringed in Denmark.Lesser Black-backed Gull intermedius DKC 4041636 28CY, October 27 1999, Westkapelle, the Netherland. Picture: Pim Wolf.
adult intermedius in October, ringed in Denmark.Lesser Black-backed Gull intermedius DKC 4041916 27CY, October 26 1999, Westkapelle, the Netherland. Picture: Pim Wolf.
adult intermedius in October, ringed in Denmark.Lesser Black-backed Gull intermedius DKC 4124822 13CY, October 25-27 1999, Westkapelle, the Netherland. Picture: Pim Wolf.
adult intermedius in October, ringed in Denmark. (71780 bytes)Lesser Black-backed Gull intermedius DKC 4130670 15cy, October 04 2004, Westkapelle, the Netherlands. Picture by Pim Wolf.
adult intermedius in October, ringed in Denmark. (72633 bytes)Lesser Black-backed Gull intermedius DKC 4253409 7CY-8CY, October 2003, IJmuiden & October 2004 Westkapelle, the Netherlands.
adult intermedius in October, ringed in Denmark. (112876 bytes)Lesser Black-backed Gull intermedius xxx adult, Westkapelle, the Netherlands, October 19 2004. Photo by Pim Wolf.

.Norway: intermedius
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adult intermedius lbbg in October, ringed in Norway. (94818 bytes)Lesser Black-backed Gull intermedius JJ5A 5CY, October 09 2009, IJmuiden, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (94818 bytes)Lesser Black-backed Gull intermedius JM79 adult, October 19 2002, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (65103 bytes)Lesser Black-backed Gull intermedius JS26 8+cy, October 10 2004, Westkapelle, the Netherlands. Picture by Pim Wolf.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull intermedius J5YL 5+cy, October 14 2012, Westkapelle, the Netherlands.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull intermedius J6UX adult, October 01 2013, Portimao, Portugal. Picture: Carl Baggott.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull intermedius JE8J adult, October & December 2012, Madrid, Spain. Photo by Delfín González.
adult intermedius lbbg in October, ringed in Norway. (90595 bytes)Lesser Black-backed Gull intermedius JU5H adult October 24 2015, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (90595 bytes)Lesser Black-backed Gull intermedius NOS 41699 adult, October 22 2001, Westkapelle, the Netherlands.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull intermedius NOS 492155 15CY, October 20 1999, Westkapelle, the Netherlands. Picture: Pim Wolf.
juvenile LBBG in October, ringed in Norway. (131273 bytes)Lesser Black-backed Gull intermedius NOS 492441 20 & 25CY, October & November, Westkapelle, the Netherlands. Picture Pim Wolf.
adult intermedius lbbg in October, ringed in Norway. (81887 bytes)Lesser Black-backed Gull intermedius NOS 4100410 18CY-19CY, October 2003 & September 2004, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (55754 bytes)Lesser Black-backed Gull intermedius NOS 4105805 5CY, October 02 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)Lesser Black-backed Gull intermedius NOS 4107889 adult, October 01 2009, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Norway.Lesser Black-backed Gull intermedius NOS 4108778 14CY, October 27 1999, Westkapelle, the Netherland. Picture: Pim Wolf.
adult intermedius lbbg in October, ringed in Norway. (137939 bytes)Lesser Black-backed Gull intermedius NOS 4119689 22+cy, October 19 2004, Westkapelle, the Netherlands. Picture by Pim Wolf.
adult intermedius lbbg in October, ringed in Norway. (75971 bytes)Lesser Black-backed Gull intermedius NOS 4170571 12CY, October 19 2004, Westkapelle, the Netherland.
adult intermedius lbbg in October, ringed in Norway. (74314 bytes)Lesser Black-backed Gull intermedius NOS 4178002 14CY, October 21 2004, Westkapelle, the Netherlands. Picture by Pim Wolf.
5491int4196602.jpg (58985 bytes)Lesser Black-backed Gull intermedius NOS 4196602 9CY, October 04 2002, Le Portel / Boulogne-sur-Mer, NW France.
adult intermedius lbbg in October, ringed in Norway. (99830 bytes)Lesser Black-backed Gull intermedius NOS 4199556 10CY, October 21 2004, Westkapelle, the Netherlands. Picture by Pim Wolf.
adult intermedius lbbg in October, ringed in Norway. (62093 bytes)Lesser Black-backed Gull intermedius NOO NA-08134 adult, October 19 2004, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (51593 bytes)Lesser Black-backed Gull intermedius NOO NA-0846x adult, October 10 2003, Scheveningen, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (77684 bytes)Lesser Black-backed Gull intermedius NOO NA-09175 adult, October 18 2002 Westkapelle, the Netherlands.

.Sweden: intermedius
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adult intermedius lbbg in October, ringed in Sweden. (80211 bytes)Lesser Black-backed Gull intermedius SVS 8072924 15CY, October 19 2004, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Sweden. (102169 bytes)Lesser Black-backed Gull intermedius SVS 8080900 11CY, October 19 2004, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Sweden. (102169 bytes)Lesser Black-backed Gull intermedius SVS 8088508 11CY, October 22 2009, Westkapelle, the Netherlands.
adult intermedius lbbg in October, ringed in Sweden. (102169 bytes)Lesser Black-backed Gull intermedius SVS 8105583 7+CY, October 06 2009, Westkapelle, the Netherlands.
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Adults ringed in winter in Portugal
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Lesser Black-backed Gull graellsii F620 adult, October 07 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull M:011 adult, September - November 2016, Matosinhos, Portugal. Picture: José Marques.
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Ringed adults intermedius (no ring-data received yet)
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5488int04546.jpg (63731 bytes)Lesser Black-backed Gull intermedius ?04546 adult, October 04 2002, Le Portel / Boulogne-sur-Mer, NW France.
Lesser Black-backed Gull intermedius 408972 adult, Breskens, the Netherlands, October 20 1999. Photo by Pim Wolf. Most probably with Stavanger (Norway) ring.
Lesser Black-backed Gull intermedius 492155 adult, Breskens, the Netherlands, October 20 1999. Photo by Pim Wolf. Most probably with Stavanger (Norway) ring.
Lesser Black-backed Gull intermedius ..746.. adult, Breskens, the Netherlands, October 20 1999. Photo by Pim Wolf.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull N537 adult, October 05 2005, Westkapelle, the Netherlands.
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Unringed adults in October
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7435.jpg (59166 bytes)Link to 13 unringed adult LBBG, October 22 2001, Westkapelle, the Netherlands.