Lesser Black-backed Gull- Kleine Mantelmeeuw (graellsii & intermedius)

(last update: 30 April 2014)

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adult: September

By September, the large majority of adult LBBG have left the Netherlands and must have move south towards Portugal. Many of the Dutch adults, which were seen feeding youngs and those suspending primary moult start migrating and must have joint these migrating groups. Nevertheless, many adults can still be found in the Netherlands, but as September progresses, more adults from Scandinavian intermedius colonies move in. This may be a reason for the "observed mere stand-still in primary moult progress" in adults: less advanced individuals from Scandinavia congregate with local Dutch intergrades. 

In this September Section we present primary moult score surveys 2001 & 2002 from the Netherlands (Maasvlakte) and NW France (Boulogne-sur-Mer). No definite conclusions on geographical variations can be drawn from these data. Therefore we started to focus on ringed adults only from year 2003 onwards;  metal ringed and Darvic ringed birds of known origin. 
Anyone checking local Lesser Black-backed Gulls in September will have noticed the large individual variation in primary moult scores. The commencement and pace of primary moult is an individual "choice", influenced by other prime goals like feeding pulli and migration. The birds observed in NW Europe apparently "chose" to stay and their September primary moult scores are not necessarily representative for "average NW European LBBG", as we simply do not know the primary moult strategy of early migrating adults.
So two question can be raised: how to exclude influences from northern populations and what PMS can be expected in early migrating birds? 
Best option to reduce the second problem culd be found in simultaneous counts along the entire West European coastline, or counts which only involve ringed individuals (thus from certain origin) at stop-overs and winter quarters. Particularly those adults which migrate south as soon and as quick as possible, may be found with low PMS or suspended moult.
In the Netherlands we concentrate on ringed individuals to eliminate the first problem (intermedius joining local Dutch intergrades), but we still have insufficient ring observations to make reliable analyses possible. 
The problem of (presumed) later moulting intermedius, moving into early moulting graellsii groups is not a problem restricted to adults, but applies to other age-classes as well.

Although the input of later moulting intermedius may be expected, the average primary moult score is hardly influenced as it seems. From the table below, the average "remaining old primary score" falls by almost two primaries over a period of 4 weeks. This matches nicely with the August estimates. 

remaining old primaries in adult LBBG's, Maasvlakte, September 2001.
  10 9 8 7 6 5 4 3 2 1 0 n: m: V: SD: SE:
01/09 3 3 6 5 15 47 38 19 1 - - 137 4,9 2,46 1,57 0,13
11/09 2 2 5 9 7 16 53 81 31 9 - 215 3,7 2,75 1,66 0,11
17/09 - - 1 2 6 11 24 39 11 4 - 98 3,6 1,77 1,33 0,13
28/09 - - - 2 5 14 23 62 40 10 - 156 3,1 1,51 1,23 0,10
First cell (10, 01/09 = 3) should be read: on September first, 3 adults had all 10 primaries old, hence showed no primary moult yet (this is about 2% on 137 observed adults that day).
n: observations, m: average, V: variance (s2), SD: standard deviation (s), SE: standard error (s· n½).

 

Old and new primaries in adult LBBG's, Dannes (NW France), Sept 21-22 2002.
old prims p6 old p7 old p8 old p9 old p10 old no old n old:
p7 new - - - - 6 5 11
p6 new - - 4 45 18 1 68
p5 new - - 39 18 2 - 59
p4 new - 7 1 - - - 8
p3 new 4 - - - - - 4
? new 1 10 2 - - - 13
n new: 5 17 46 63 26 6 163

As can be seen in the table, the average LBBG has a three primaries moult gap.

Subspecific PMS: graellsii

In the Netherlands, the nominate type graellsii can be found in low numbers in September. Normally, they can be recognized by their slightly paler grey upper-parts, fiercer facial expression, stockier jizz and more advanced PMS. By September, adult graellsii may arrive from Britain, but the nominate form also can be found breeding in Belgian and Dutch colonies. 
We do not collect sufficient field data on ringed graellsii in the Netherlands to draw any conclusions; notwithstanding the fact that September adults disperse throughout the entire southern part of the North Sea, following vessels on rich fishing grounds and taking rest at the closest beaches, either in Britain, Belgium or the Netherlands. 
There are hardly articles or papers dealing with September adult LBBG. By far the most extensive surveys were done by the Severn Estuary Gull Group in Gloucestershire, with LBBG-expert Peter Stewart. He wrote two papers on PMS of British graellsii, one still in preparation.

During the period February 1986 to October 2001 no less than 12,842 LBBG were caught using cannon-nets, and from this total 6,539 PMS were recorded. For the month September, 407 adults have been recorded. The number of old primaries present in adults are presented in the table below. Peter uses half monthly intervals.

Extracted from: Table 3. The number of old primaries present during the moulting season.

time interval mean (m) range sample size (n)
Sept 01-15 3.3 0-7 234
Sept 16-30 2.1 0-7 173

Table 3 from "The primary moult of the Lesser Black-backed Gull" by Peter Stewart (in prep, 2002). Special Publication No 1 by The Severn Estuary Gull Group.

Peter also recorded the PMS of adult birds, using the method described by Ginn & Melville (1983). Each primary receives a score: score 0 (old feathers), score 1 (old feather missing, new feather completely in pin), score 2 (new feather visible up to 1/3), score 3 (growing feather 1/3 to 2/3),  score 4 (growing feather more than 2/3, still with basal waxy sheath), score 5 (new feather fully grown). The total PMS for all 10 primaries varies from 0 to 50 for any single wing.

Extracted from: Table 9. The PMS at half-monthly intervals in adults (aggregated n: 4472).

time interval mean (m) range sample (n) moulting n moulting %
Sept 01-15 26.8 6-44 239 239 100
Sept 16-30 32.1 11-47 107 107 100

Table 9 from "The primary moult of the Lesser Black-backed Gull" by Peter Stewart (in prep, 2002). Special Publication No 1 by The Severn Estuary Gull Group.
Notes: as the minimum PMS was 6 (Sept 01-15), all birds appeared to be in active moult this month. Peter's latest not-moulting bird was August 13.

Subspecific PMS: Dutch intergrade

The form "Dutch intergrade" refers to the LBBG populations in Belgium and the Netherlands. These colonies are situated between graellsii (British Isles) and intermedius (Norway, Sweden, Demark) and breeding birds in the Netherlands and Belgium show characters of both taxa. We have extensive field surveys of primary moult scores for adult LBBG from the large colony at Maasvlakte (near Rotterdam) but the September scores may be effected by migrating intermedius, which are abundant, especially in the second half of the month. From 2003 onwards, we focus on ringed birds only, making sure birds originate from the Netherlands or Belgium. Although the figures in the table give some indication for the average PMS of Dutch LBBG, a few comments must be made:
1. The PMS recorded here refer to LBBG which are still in the Netherlands. We don't have sufficient data to draw conclusions on the complete Dutch population.
2. Different colonies are involved, with birds from Maasvlakte, IJmuiden and Moerdijk (inland location).
3. Although it seems easy to construct a PMS progression line, this is not wise. Especially the counts for September involve many different birds, only seen on one or a few occasions. Individual birds follow different moult strategies, and this may vary between Dutch colonies. 

The number of old primaries present during the moulting season in ringed adult LBBG from Belgium & the Netherlands 2003.

time interval mean (m) range sample size (n)
Sept 01-15 3.2 2-5 26
Sept 16-30 2.4 0-4 32

Notes:
Early September counts involve some individuals more than once (e.g. E119 green).

Subspecific PMS: intermedius

The form intermedius breeds in Norway, Sweden and Demark. Compared to either graellsii or Dutch intergrades, intermedius is on average a late moulting bird. Most birds are a shade of grey darker than Dutch intergrades, but some intermedius appear just as grey and robust as the average local Dutch intergrade. However, strong western September winds may bring the typical small intermedius to Dutch shores, very dark grey (almost blackish) with typical jizz: short necked, short legged, attenuated rear end and dove-like appearance. And often a remarkable low PMS. The few comments made under the Dutch intergrade caption apply to intermedius as well.

The number of old primaries present during the moulting season in ringed adult LBBG from Norway, Sweden & Denmark 2003.

time interval mean (m) range sample size (n)
Sept 01-15 4.5 2-7 24
Sept 16-30 3.8 2-5 9

Notes:
PMS of intermedius LBBG do not necessarily reflect the average of the complete population, as intermedius is known to appear far south early in the season, and in particular these birds may follow a different moult strategy.

Peter Stewart has caught intermedius in Britain. He only recorded 10 birds for September on a total of 68 birds. The average PMS for intermedius "falls mainly between the mean and lowest moult scores obtained for adult graellsii", according to Peter. However, intermedius may show a very advanced PMS as well, already by mid-August.

Extracted from: Table 18. Summary of PMS for 68 L.f. intermedius at half-monthly intervals in adults.

time interval mean (m) range sample (n) moulting n moulting %
Sept 01-15 20.1 12-28 9 9 100
Sept 16-30 27.0 27 1 1 100

Table 18 from "The primary moult of the Lesser Black-backed Gull" by Peter Stewart (in prep, 2002). Special Publication No 1 by The Severn Estuary Gull Group.
Notes: as the minimum PMS was 12 (Sept 01-15), all birds appeared to be in active moult this month. Peter didn't catch any none-moulting bird so far.

conclusions

As could be expected, LBBG which spend the month of September along the Dutch coast may origin from many different colonies. The PMS of either graellsii, Dutch intergrades or intermedius do not necessarily reflect the average of a complete LBBG population, as many birds quickly migrate south, early in the season. Particularly these birds may follow a different (delayed) moult strategy.

Tables & Graph

starting date:   27 Aug   03 Sep   10 Sep   17 Sep   24 Sep   01 Oct
week no: 35 36 37 38 39 40
REM 0 0 0 0 6 0 2
REM 1 0 0 9 38 19 1
REM 2 3 4 33 95 85 2
REM 3 66 25 100 111 123 2
REM 4 187 24 57 51 44 0
REM 5 182 4 17 17 24 0
REM 6 105 0 7 6 9 0
REM 7 33 0 9 2 5 0
REM 8 25 0 5 1 1 0
REM 9 15 0 2 0 0 0
REM 10 14 0 2 0 0 0
0 0 0 0 0 0
n = 630 57 241 327 310 7
average P = 5.1 3.5 3.6 2.8 3.1 1.6
95% CID = 0.12 0.19 0.20 0.14 0.14 1.18
inverse = 1.96 2.00 1.97 1.97 1.97 2.45
Variantie (s2) = 2.43 0.54 2.52 1.58 1.57 1.62
SD (s) = 1.56 0.73 1.59 1.26 1.25 1.27
SE (sx) = 0.06 0.10 0.10 0.07 0.07 0.48
             
% class:            
0 0 0 0 2 0 29
1 0 0 4 12 6 14
2 0 7 14 29 27 29
3 10 44 41 34 40 29
4 30 42 24 16 14 0
5 29 7 7 5 8 0
6 17 0 3 2 3 0
7 5 0 4 1 2 0
8 4 0 2 0 0 0
9 2 0 1 0 0 0
10 2 0 1 0 0 0
             
  % control: 100 100 100 100 100 100

  Table above, data for the Netherlands (2000-2010), results for September (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 September (arrested moult excluded). Sample size for this graph is 278 ringed birds + 1294 unringed birds.

starting date:

27-Aug

10 Sep

17 Sep

24 Sep

08 Oct

week no:

35

37

38

39

41

NEW 0

1

0

0

0

0

NEW P1

0

0

0

0

0

NEW P2

2

0

0

0

0

NEW P3

12

0

4

0

0

NEW P4

25

6

11

4

0

NEW P5

5

13

65

10

1

NEW P6

0

11

73

4

12

NEW P7

0

3

15

0

5

NEW P8

0

0

0

0

0

NEW P9

0

0

0

0

0

NEW P10

 

 

 

 

 

 

 

 

 

 

 

n =

45

33

168

18

18

average NEW P =

3.7

5.3

5.5

5.0

6.2

95% CID =

0.27

0.32

0.13

0.34

0.27

inverse  =

2.02

2.04

1.97

2.11

2.11

Variantie (s2) =

0.82

0.79

0.71

0.47

0.30

SD (s) =

0.90

0.89

0.84

0.69

0.55

SE (sx) =

0.13

0.15

0.06

0.16

0.13

 

 

 

 

 

 

% class

 

 

 

 

 

0

2

0

0

0

0

1

0

0

0

0

0

2

4

0

0

0

0

3

27

0

2

0

0

4

56

18

7

22

0

5

11

39

39

56

6

6

0

33

43

22

67

7

0

9

9

0

28

8

0

0

0

0

0

9

0

0

0

0

0

10

0

0

0

0

0

 

 

 

 

 

 

% control:

100

100

100

100

100

 

  Table above, data for the Netherlands (2000-2010), results for September (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 September (arrested moult excluded). Sample size for this graph is 112 ringed birds + 152 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.

Britain: LBBG graellsii
juvenile LBBG, ringed in the Netherlands. LBBG 1KH September 21 2008, Madrid, Spain. Photo by Delfín González.
adult LBBG graellsii in September, ringed in Brittain. (59807 bytes)LBBG GBT GN 62664 September 04 2010, Leiden, the Netherlands.
Lesser Black-backed Gull 28cy BTO GK38437 2008-2011, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG graellsii in September, ringed in Brittain. (59807 bytes)LBBG GBT GG 63019 September 02 2003, Westkapelle, the Netherlands.
adult LBBG graellsii in September, ringed in Brittain. (65704 bytes)LBBG GBT GG 44337 September 02 2003, Westkapelle, the Netherlands.

Belgium: LBBG "Dutch intergrade"
adult LBBG Dutch intergrade in September, ringed in Belgium. (61842 bytes)LBBG 5cy BLB L-87152 September 02 2003, Westkapelle, the Netherlands. 5cy, ringed in 1999.
Lesser Black-backed Gull 7cy BLB L-900115 September 03 2010, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in Belgium. (60645 bytes)LBBG 7+cy BVAM September 02 2003, Westkapelle, the Netherlands.
ad LBBG in October, ringed in the Netherlands. (60900 bytes)Dutch intergrade 15cy & 17cy DKAN October 2009 & September 2011, Westkapelle, the Netherlands.

the Netherlands: LBBG "Dutch intergrade"
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (85708 bytes)LBBG NLA 5.326.111 September 02 2003, Westkapelle, the Netherlands.
Lesser Black-backed Gull 14-15cy NLA 5.330.969 September 2010 & August 2011, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (85708 bytes)LBBG 15CY TNSeptember 13 2013, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (85708 bytes)LBBG AX September 15 2010, Westkapelle, the Netherlands.
Lesser Black-backed Gull adult D7 August - September 2010, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (85708 bytes)LBBG PC September 23 2010, Westkapelle, the Netherlands.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80494 bytes)LBBG M.AAV September 08 2008, Madrid, Spain. Photo by Delfín González.
adult intermedius lbbg in October, ringed in Norway. (94818 bytes)LBBG ad Y.ABY September 01 2011, IJmuiden, the Netherlands.
Lesser Black-backed Gull adult Y.AHJ 2009-2011, France & the Netherlands. Pictures: Ruud Altenburg & Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80494 bytes)LBBG Y.AKU September 12 2010, IJmuiden, the Netherlands.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80494 bytes)LBBG Y.AKZ 2010-2011, IJmuiden-Westkapelle, the Netherlands.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (83259 bytes)LBBG P84 September 27 2004, Westkapelle, the Netherlands. Ringed as pullus in 1991.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80008 bytes)LBBG JP0 September 23 2010, Westkapelle, the Netherlands.
Lesser Black-backed Gull 15cy EJ83 August-September 2010, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80008 bytes)LBBG ES29 September 02 2003, Westkapelle, the Netherlands.
Lesser Black-backed Gull 12cy EX68 September 02 2008, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80494 bytes)LBBG E703 September 02 2003, Westkapelle, the Netherlands.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (80494 bytes)LBBG 10cy EAH9 September 23 2006, Madrid, Spain. Photo by Delfín González. Also as 6 & 8cy.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (93901 bytes)LBBG EP94 September 30 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
adult intermedius lbbg in October, ringed in Norway. (94818 bytes)LBBG 15cy RS7 September 01 2011, IJmuiden, the Netherlands.
adult intermedius lbbg in October, ringed in Norway. (94818 bytes)LBBG ad X11 September 01 2011, IJmuiden, the Netherlands.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (72865 bytes)LBBG E494 September 20 2003, IJmuiden, the Netherlands.
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (85708 bytes)LBBG E225 September 01 2010, Westkapelle, the Netherlands.
ad LBBG in August, ringed in the Netherlands. (57118 bytes)LBBG N527 September 02 2010, Heemskerk, the Netherlands. Ringed in Spain in winter.

Germany: transition graellsii - intermedius
adult LBBG Dutch intergrade in September, ringed in the Netherlands. (85708 bytes)LBBG 4cy H.010 September 01 2010, Westkapelle, the Netherlands.
2cy intermedius in October, ringed in Norway. (97235 bytes)LBBG H.501 September - October 2010, Leiden, the Netherlands.

Denmark: LBBG intermedius
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)LBBG VC5M September 23 2010, Westkapelle, the Netherlands.

Norway: LBBG intermedius
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)LBBG J29E September 24 2009, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)LBBG JH77 September 23 2010, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)LBBG JP0P September 24 2009, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (66727 bytes)LBBG JCA0 September 20 2003, IJmuiden, the Netherlands.
1cy argenteus in November, ringed in Belgium. (25637 bytes)LBBG JMP8 September 27 2007, Westkapelle, the Netherlands. Picture Pim Wolf.
adult LBBG intermedius in September, ringed in Norway. (95609 bytes)LBBG JU28 September 28 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
adult LBBG intermedius in September, ringed in Norway. (114057 bytes)LBBG NOS 4100410 (19cy) September 27 2004, Westkapelle, the Netherlands. Picture Pim Wolf. Returning adult.
adult LBBG intermedius in September, ringed in Norway. (74676 bytes)LBBG NOS 4107441 (18cy) September 02 2003, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (122245 bytes)LBBG NOS 4147932 September 07 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
adult LBBG intermedius in September, ringed in Norway. (59027 bytes)LBBG NOS 4153395 (14cy) September 02 2003, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (73318 bytes)LBBG NOS 4164893 (14cy) September 02 2003, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (59137 bytes)LBBG NOS 416x044 September 02 2003, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (76305 bytes)LBBG NOS 416x366 September 22 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (67044 bytes)LBBG NOS 4178117 (13cy) September 26 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (69625 bytes)LBBG NOS 4178334 (13cy) September 20 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (67998 bytes)LBBG NOS 4194962 (9cy) September 20 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (67998 bytes)LBBG NOS 4196376 (17cy)September 23 2010, Westkapelle, the Netherlands.
adult LBBG intermedius in September, ringed in Norway. (63432 bytes)LBBG NOS 4209546 September 22 2002, Le Portel, France.
Lesser Black-backed Gull 8cy NOS 4241800 September 11 2010, Boulogne sur mer, NW France. Picture: Jean-Michel Sauvage.
adult LBBG intermedius in September, ringed in Norway. (58599 bytes)LBBG NOO NA11199 September 19 2003, IJmuiden, the Netherlands.

Sweden: LBBG intermedius
adult LBBG intermedius in September, ringed in Sweden. (51515 bytes)LBBG intermedius SVS 8362147 September 20 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Sweden. (69000 bytes)LBBG intermedius SVS 8101867 September 20 2003, IJmuiden, the Netherlands. Probably from Sweden.
adult LBBG intermedius in September, ringed in Sweden. (64709 bytes)LBBG intermedius SVS 8099xxx September 26 2003, IJmuiden, the Netherlands.
adult LBBG intermedius in September, ringed in Sweden. (64709 bytes)LBBG intermedius 18CY SVS 8081117 September 23 2010, Westkapelle, the Netherlands.

unringed LBBG in September
6460.jpg (101670 bytes)Photo 1: LBBG adult, September 30 2001, Le Portel, France.
6541.jpg (82131 bytes)Photo 2 : LBBG adult, September 30 2001, Dannes - Le Portel France.
5978.jpg (81142 bytes)Photo 4: LBBG adult, September 2 2001, Missouriweg Maasvlakte, the Netherlands.
6016.jpg (93812 bytes)Photo 5: LBBG adult, September 2 2001, ECT parking Maasvlakte, the Netherlands.
6023.jpg (83170 bytes)Photo 6: LBBG adult intermedius, September 2 2001, ECT parking Maasvlakte, the Netherlands.
6027.jpg (79366 bytes)Photo 7: LBBG adult, September 2 2001, ECT parking Maasvlakte, the Netherlands.
6036.jpg (97314 bytes)Photo 8: LBBG adult, September 2 2001, Brouwersdam, the Netherlands.
6044.jpg (89122 bytes)Photo 9: LBBG adult, September 2 2001, Brouwersdam, the Netherlands.
6049.jpg (94449 bytes)Photo 10: LBBG adult, September 2 2001, Brouwersdam, the Netherlands.
6225.jpg (93864 bytes)Photo 11: LBBG adult?, September 17 2001, Vuurtorenvlakte Maasvlakte, the Netherlands.
6238.jpg (86868 bytes)Photo 12: LBBG adult, September 17 2001, Vuurtorenvlakte Maasvlakte, the Netherlands.
6437.jpg (90608 bytes)Photo 13: LBBG adult, September 30 2001, Le Portel, France.
6542.jpg (76904 bytes)Photo 14: LBBG adult, September 30 2001, Dannes - Le Portel, France.
6543.jpg (87214 bytes)Photo 15: LBBG adult, September 30 2001, Dannes - Le Portel, France.