adult: October
Last update of
this page: 30-03-05 09:17
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.
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
Remaining
old primaries for adult LBBG year 2001 (the Netherlands) |
. |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
n: |
m: |
Oct
8-12 |
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. |
|
Britain:
'graellsii'
|
graellsii ad APF October
21 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
graellsii ad ATN October
22 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
graellsii 6cy LSY October
22 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
graellsii ad YLS October
19 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
graellsii ad GG-63238
Westkapelle, the Netherlands, October 04 2004. Photo by Pim Wolf. |
Belgium: 'Dutch intergrade'
|
Dutch intergrade
BLB
L - 7400? October 05 2002, Le Portel /
Boulogne-sur-Mer,
NW France. Ringed in Belgium. |
Dutch intergrade
BLB
L - 80954 October 22 2001, Westkapelle, the Netherlands.
Ringed in Belgium. |
Dutch intergrade
5cy BLB
L
- 85168 October 30 2003, Westkapelle, the Netherlands.
Ringed in Belgium. |
the Netherlands: ' Dutch intergrade'
|
Dutch intergrade 5cy ECJ9 October 14 2001,
Westkapelle, the
Netherlands. Born summer 1997 in
the Netherlands. |
Dutch intergrade 9cy EN22 October
19 2004, Westkapelle, the
Netherlands. Born summer 1996 in
the Netherlands. |
Dutch intergrade 11cy JP2 October
11 2003, Westkapelle, the
Netherlands. Ringed July 04 1993 at Maasvlakte, the Netherlands. |
Dutch intergrade 11cy KN8 October
03 2003, Scheveningen, the
Netherlands. Ringed July 01 1993 at Maasvlakte, the Netherlands. |
Dutch intergrade
10cy E737 October
04 2004, Westkapelle, the
Netherlands. Picture Pim Wolf. |
Dutch intergrade 8cy EL74 October
11 2003, Westkapelle, the
Netherlands. Ringed June 25 1996 at Maasvlakte, the Netherlands. |
Dutch intergrade 6cy ECK1
October 03 2002, Boulogne-sur-Mer, NW France. Born summer 1997 in the
Netherlands. |
Dutch intergrade
6cy
EH10
Westkapelle, the Netherlands, October 21 1999. Photo by Pim Wolf. Born
summer 1994 in the Netherlands. |
Dutch intergrade
7+cy
ER73
Westkapelle, the Netherlands, October 15 & 27 1999. Photo by Pim
Wolf. Ringed as an adult on the nest, summer 1997 in the Netherlands. |
Dutch intergrade
5cy E214 October
04-07 2004, Westkapelle, the
Netherlands. Picture Pim Wolf. |
Dutch intergrade
5cy E219 October
01 2004, Westkapelle, the
Netherlands. Picture Pim Wolf. Also seen as 2cy at Westkapelle. |
Dutch
intergrade
5.362.926 October 13 2001,
Westkapelle, the Netherlands.
Metal-ringed Dutch bird.
|
Denmark: intermedius
|
intermedius 9cy
467213
October 14 2001,
Westkapelle, the Netherlands. Ringed
in Denmark: Veno, Struer, Jylland (56.33N 08.37E). |
intermedius 28cy 4041636
Weskapelle, the Netherlands, October 27 1999. Ringed at Anholt, Denmark
in 1972. Photo by Pim Wolf. |
intermedius 26cy 4041916
Westkapelle, the Netherlands, October 26 1999. Photo by Pim Wolf. |
intermedius 13cy 4124822
Westkapelle, the Netherlands, October 25-27 1999. Photo by Pim Wolf. This
bird is ringed in Jylland, Denmark (56.39N 08.14E) as pullus on June 14
1987. |
intermedius 4130670
Westkapelle, the Netherlands, October 04 2004. Photo by Pim Wolf. |
intermedius 4253409
IJmuiden & Westkapelle, the Netherlands, October 2003 &
October 2004. |
intermedius
xxx
Westkapelle, the Netherlands, October 19 2004. Photo by Pim Wolf. |
Norway:
intermedius
|
intermedius
5cy+ JM79 October
19 2002, Westkapelle, the Netherlands.
Ringed in Norway. |
intermedius JS26 October
10 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
intermedius
41699 October 22 2001,
Westkapelle, the Netherlands.
Ringed Stavanger, Norway. |
intermedius 492441
October 19 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
intermedius
18cy 4100410 October
11 2003, Westkapelle, the Netherlands. |
intermedius 4105805
IJmuiden, the Netherlands, October 02 2003. |
intermedius 14cy 4108778
Westkapelle, the Netherlands, October 27 1999. Photo by Pim Wolf. NOS
4108778 Slettingen, Mandal, Vest-Agder, ringed as pullus on July 04 1986. |
intermedius 4119689
October 19 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
intermedius
4175071 October
19 2004, Westkapelle, the Netherlands. |
intermedius 4178002
October 21 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
intermedius 4199556
October 21 2004, Westkapelle, the Netherlands. Picture Pim Wolf. |
intermedius
NOO
NA 08134 October 19 2004, Westkapelle, the Netherlands. |
intermedius
NOO NA
0846? October 10 2003, Scheveningen, the Netherlands.
Ringed Oslo, Norway. |
intermedius
NOO NA
09175 October 18 2002, Westkapelle, the Netherlands.
Ringed Oslo, Norway. |
Sweden:
intermedius
|
intermedius LBBG
SVS
8072924, October 19 2004, Westkapelle, the Netherlands. |
intermedius LBBG
SVS
8080900, October 19 2004, Westkapelle, the Netherlands. |
Ringed adults
intermedius
(no ring-data received yet)
|
LBBG
intermedius ?04546,
October 04 2002, Le Portel / Boulogne-sur-Mer, NW France. |
LBBG
intermedius adult 408972,
Breskens, the Netherlands, October 20 1999. Photo by Pim Wolf. Most
probably with Stavanger (Norway) ring. |
LBBG
intermedius adult 492155,
Breskens, the Netherlands, October 20 1999. Photo by Pim Wolf. Most
probably with Stavanger (Norway) ring. |
LBBG
intermedius adult ..746..,
Breskens, the Netherlands, October 20 1999. Photo by Pim Wolf. |
LBBG
intermedius 4196602,
October 04 2002, Le Portel / Boulogne-sur-Mer, NW France. |
Unringed adults in
October
|
Link
to 13 unringed adult LBBG, October 22 2001, Westkapelle, the Netherlands.
Several unringed birds of unknown origin; including fuscus-like birds. |