Great Black-backed Gull (Larus marinus)

(last update: October 12, 2011)

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.

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Primary moult score of September 2cy GBBG L. marinus, birds in the section of this website. Ringed birds, (+ unringed in brackets).
P7 fully grown 2 JE218, DEH3112361
P8 fully grown 3 (+4) JA686, JE576, JL50
P9 fully grown 9 (+3) JE62, JL6M, J713W, JA222, JE252, JH709, JK37, JM06, 48C
P10 fully grown 0  
n (sample size): 21  
m (average): 8,5  
SD (stand dev): 0,68  

Notes:
m (average) = number of remaining old juvenile primaries.
2x P7 fully grown, one bird with retained juvenile P10 (JE218).

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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

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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 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.
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 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.
6442.jpg (81236 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 30 2001, Le Portel - Boulogne/Mer, France (50.42 N - 01.34 E).
Primary p10 still has to grow a few inches and is at the length of p7, p9 is fully grown.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: September 20 2003, IJmuiden, the Netherlands (52.27 N - 04.33 E).
Primary P8 is fully grown.