Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Coordinators:
Jean-Michel Sauvage (France)
Morten Helberg (Norway)
Nils Helge Lorentzen (Norway)
Mars Muusse (Netherlands)

Great Black-backed Gull 2cy September

Birds in the very last phase of the complete moult. Outer primaries only have to grown a few inches to finish this complete moult, which ends by definition when P10 is fully grown. At the same time, a partial autumn moult may be seen, which has the most common strategy including new upper tertials, innermost greater coverts, relatively large number of inner median coverts, random some lower lesser coverts and lesser coverts. However, variation on this partial moult extent are common; and some birds may completely skip such a moult in autumn. The true extent of the partial autumn moult can be told from observations from November onwards; by September we only witness the start of this process, with single upper tertials or inner coverts missing.

Tables

Primary moult score of 2cy GBBG L. marinus.
September 21 2002 - Boulogne/Mer, NW France (50.43N,01.37E).

Bert-Jan Luijendijk & Mars Muusse.
P7 fully grown 2
P8 fully grown 6
P9 fully grown 2
P10 fully grown 0
n (sample size): 10
m (average): 8,0
SD (stand dev): 0,67

Notes:
m (average) = number of fully grown new 2nd gen primaries. Fully grown score = tip of the feather exceeds the previous feather, even fractionally.
2x P7 fully grown, both birds with retained juvenile P10.

.

Primary moult score of September 2cy GBBG L. marinus, ringed birds in September on this website.
P7 fully grown 3 JE218, 5T9, DEH3112361
P8 fully grown 4 JA686, JE576, JL50, 1KH
P9 fully grown 14 JE62, JL6M, J713W, JA222, JE252, JH709, JU144, JU754, JU818, JK37, JM06, 48C, 58P, DKC3M3220
P10 fully grown 0 .
n (sample size): 21 .
m (average): 8,5 .
SD (stand dev): 0,75 .

Notes:
m (average) = number of new fully grown primaries. Fully grown in this definition: when in a resting bird the feather exceeds the previous in length (note, this feather may still ahev to grow a little to get its final length).
2x P7 fully grown, one bird with retained juvenile P10 (JE218).

.

marinus age scored against fully grown new primaries, September 21 2002, Boulogne-sur-Mer, NW France (on the roof).
. p5 new p6 new p7 new p8 new p9 new p10 new m = n = SD =
2nd cy - - 2 6 2 - 8,0 10 0,67
3rd cy - - 7 1 - - 7,1 8 0,35
4th cy - 1 3 - - - 6,8 4 0,25
adult 35 40 - - - - 5,4 82 0,65

.

remaining 
1
2
3
4
5
6
7
7
8
8
9
10
11
12
remain/new P       
rem
rem
rem
rem
rem
rem
rem
new
rem
new
new
new
new
n(tot) 213
jan
feb
mrch
apr
may
june
july
july
aug
aug
sept
oct
nov
dec
0
.
.
.
.
.
.
1
.
11
.
.
.
.
.
1
.
.
.
.
.
.
.
.
8
.
.
.
.
.
2
.
.
.
.
.
1
3
.
3
.
.
.
.
.
3
.
.
.
.
.
8
4
.
.
.
.
.
.
.
4
.
.
.
.
2
10
.
.
.
.
.
.
.
.
5
.
.
.
.
4
.
.
5
.
.
.
.
.
.
6
.
.
.
1
4
.
.
2
.
6
.
.
.
.
7
.
.
.
.
6
.
.
.
.
13
3
.
.
.
8
.
.
.
.
2
.
.
1
.
2
4
2
1
.
9
.
.
.
2
.
.
.
.
.
.
14
5
4
.
10
31
32
24
5
.
.
.
.
.
.
.
6
6
7
n=
31
32
24
8
18
19
8
8
22
21
21
13
11
7
average m:
10,0
10,0
10,0
9,3
6,1
3,5
2,3
5,6
0,6
6,8
8,5
9,3
9,5
10,0
95% CID
0,00
0,00
0,00
1,16
0,61
0,29
0,87
0,89
0,32
0,27
0,34
0,45
0,46
0,00
inverse 
2,04
2,04
2,07
2,36
2,11
2,10
2,36
2,36
2,08
2,09
2,09
2,18
2,23
2,45
Variance (s2)
0,00
0,00
0,00
1,93
1,52
0,37
1,07
1,13
0,53
0,36
0,56
0,56
0,47
0,00
SD (s)
0,00
0,00
0,00
1,39
1,23
0,61
1,04
1,06
0,73
0,60
0,75
0,75
0,69
0,00
SE (sx) 
0,00
0,00
0,00
0,49
0,29
0,14
0,37
0,38
0,15
0,13
0,16
0,21
0,21
0,00
Percentage
0
0
0
0
0
0
0
13
0
50
0
0
0
0
0
1
0
0
0
0
0
0
0
0
36
0
0
0
0
0
2
0
0
0
0
0
5
38
0
14
0
0
0
0
0
3
0
0
0
0
0
42
50
0
0
0
0
0
0
0
4
0
0
0
0
11
53
0
0
0
0
0
0
0
0
5
0
0
0
0
22
0
0
63
0
0
0
0
0
0
6
0
0
0
13
22
0
0
25
0
29
0
0
0
0
7
0
0
0
0
33
0
0
0
0
62
14
0
0
0
8
0
0
0
0
11
0
0
13
0
10
19
15
9
0
9
0
0
0
25
0
0
0
0
0
0
67
38
36
0
10
100
100
100
63
0
0
0
0
0
0
0
46
55
100
% Controll
100
100
100
100
100
100
100
100
100
100
100
100
100
100

Notes:
Sample of only ringed birds for: Jan, Febr, Mrch, July, Aug, Sept, Oct, Nov, Dec.
Sample of unringed birds for May & June
Sample of mixed ringed and unringed birds for April.

 

gbbgGreat Black-backed Gull (Larus marinus) 2cy JE62 September 26 2006, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
gbbgGreat Black-backed Gull (Larus marinus) 2cy JL6M September 09 2006, Papendrecht, the Netherlands. Picture Albert de Jong.
gbbgGreat Black-backed Gull (marinus) 2cy J713W September 24 2012, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
1598.jpg (74227 bytes)Great Black-backed Gull JA222 (Larus marinus) 2cy: September 10 2009, Westkapelle, the Netherlands.
1598.jpg (74227 bytes)Great Black-backed Gull JA686 (Larus marinus) 2cy: September 02 2009, Westkapelle, The Netherlands. Picture Ies Meulmeester.
1598.jpg (74227 bytes)Great Black-backed Gull JE218 (Larus marinus) 2cy: September 22 2011, Westkapelle, the Netherlands. Picture: M v Kleinwee.
1598.jpg (74227 bytes)Great Black-backed Gull JE252 (Larus marinus) 2cy: September 22 2011, Westkapelle, the Netherlands. Picture: M v Kleinwee.
gbbgGreat Black-backed Gull (marinus) 2cy-3cy JE576 September 12 2011 & September 25 2012, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
8471j52c.jpg (85052 bytes)Great Black-backed Gull JH709 (Larus marinus) 2cy: September 22 2011, Westkapelle, the Netherlands. Picture: M v Kleinwee.
1598.jpg (74227 bytes)Great Black-backed Gull (Larus marinus) JU144 2CY, August - September 2015 , IJmuiden, the Netherlands. Picture: Maarten van Kleinwee & Mars Muusse.
1598.jpg (74227 bytes)Great Black-backed Gull (Larus marinus) JU754 1CY-2CY, December 2014 - September 2015, IJmuiden, the Netherlands.
1598.jpg (74227 bytes)Great Black-backed Gull (Larus marinus) JU779 2CY, September 07 2016, IJmuiden, the Netherlands.
1598.jpg (74227 bytes)Great Black-backed Gull (Larus marinus) JU818 1CY-2CY, October 2014 - November 2015 , IJmuiden, the Netherlands.
1598.jpg (74227 bytes)Great Black-backed Gull JK37 (Larus marinus) 2cy: September 24 2007, Boulogne/Mer, France. Picture: J-M Sauvage.
1598.jpg (74227 bytes)Great Black-backed Gull JL50 (Larus marinus) 2cy: September 24 2007, Boulogne/Mer, France. Picture: J-M Sauvage.
1598.jpg (74227 bytes)Great Black-backed Gull JM06 (Larus marinus) 2cy: September 24 2007, Boulogne/Mer, France. Picture: J-M Sauvage.
9101.jpg (76303 bytes)Great Black-backed Gull (Larus marinus) DKC 3M3220 2CY, July & September 2015, Boulogne-sur-Mer, France. Picture: Jean-Michel Sauvage.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 58P 2CY, September 15 2015, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 2cy 48C September 02 2008, Boulogne / Mer, France. Picture Jean Michel Sauvage.
8011gbbg9158322.jpg (90352 bytes)Great Black-backed Gull (Larus marinus) DEH 3112361 2cy, August - September 2012, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage. Ringed on a ship in the North Sea.
9101.jpg (76303 bytes)Great Black-backed Gull (Larus marinus) 5T9 1cy-3cy, August 27 2011 - June 29 2013, Sandy Point - Plum Island, Ipswich, MA. 
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 1KH 2CY-3CY, September 2012 & November 2013, Dalkey, Dublin, Ireland. Picture: Stephen Lawlor.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus), 2CY, September 24 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus), 2CY, September 24 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus), 2CY, September 20 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus), 2CY, September 20 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus), 2CY, September 24 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus), 2CY, September 20 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 23 2011, Scheveningen, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 23 2011, Scheveningen, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 23 2011, Scheveningen, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 23 2011, Scheveningen, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 09 2010, IJmuiden, the Netherlands.