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 1cy September

Description of 1st winter plumage

First-winter (Sep-Mar) similar to juvenile, but head and upper breast whiter with narrower dark streaks (especially around eye and on hindneck); forehead normally white. May show dark ear-spot. Mantle and scapulars pale grey to buff with blackish subterminal bars or anchor-shaped spots; often intermixed with juvenile feathers. Bill similar to juvenile, but some develop paler base from early winter. Pale individuals have whitish underparts, narrower dark subterminal marks on upperparts and narrow dark covert-markings. With wear may bleach as described under Herring Gull, but rarely as extreme (an extremely pale spring bird shown by Grant (1989a) could to my eyes be partly leucistic, as the upperparts appear unmarked, which is atypical even in very worn birds). (Malling Olsen, K. & Larsson, H. 2004 Gulls of Europe, Asia and North America. London: Christopher Helm).

Moult into first winter

Juvenile moult to first winter plumage partial Aug-Nov, including mantle, scapulars, and (probably) parts of head and body. Often no sign of moult into Nov/Dec. (Malling Olsen, K. & Larsson, H. 2004 Gulls of Europe, Asia and North America. London: Christopher Helm).

Although Malling Olssen states "often no sign of moult into Nov/Dec", this is not supported by data of ringed birds. The table presented below for September illustrates that 60% (n = 15) do show the first signs of moult, i.e. new upper scapulars.
By October, over 90% (1 out of 23 birds) replaced the upper scapulars and 40% had started moult in the lower scapulars as well.

All wing-coverts, tertials and flight feathers still juvenile by September.

Tables:

Moult in 1cy September GBBG - ringed birds.
CODE  
US
LS
TOT SCAPS
1va blue britain september 0 0 0
25c blue france september 0 0 0
ja697 black norway september 0 0 0
ja725 black norway september 0 0 0
jh837 black norway september 0 0 0
jp132 black norway september 0 0 0
jp149 black norway september 0 0 0
3u4 black usa september 0 0 0
7j1 black usa september 0 0 0
j7rh blue france september 2 1 1
j33y black norway september 1 0 1
je676 black norway september 2 0 1
jm06 black norway september 1 0 1
nos 3020847 norway september 1 0 1
ja804 black norway september 4 1 2
jt793 black norway september 4 1 2

below: graph corresponding to data from table 1. n=16. Distribution of replaced 2nd generation scapulars in September 1cy GBBG, separated into Upper Scapulars, Lower scapulars and for Total scapular region. Classification in 6 classes, running from 0% (no 2nd gen scaps) to 100% (all scaps in a region have been replaced).

It is clear from the column "Total scapulars" that only 60% of the ringed September birds scored "0% 2nd gen scaps", in other words, the other 40% of those 16 ringed birds had replaced at least one or more (upper) scapulars for 2nd gen feathers.

below: Great Black-backed Gull JA804 illustrates differences in colour and pattern between old juvenile 1st generation scapulars and fresh buffish 2nd generation feathers. Bird ringed as pullus on June 12 2012 at Salvøy, Karmøy, Rogaland, Norway (59°17'54"N 005°12'27"E). Picture: Jean-Michel Sauvage, September 28 2012, Boulogne-sur-Mer, NW France.

below: Distribution of replaced scapulars for "Total scapular region" for months August in hatch year until commencement of first complete moult in April. Classification in 6 classes, running from 0% (no 2nd gen scaps) to 100% (all scaps, including long rear scaps, have been replaced). Only ringed birds, n=238.

Origin of all 191 ringed bird, used in our sample. Several individual birds observed in more than one month.
britain
13
denmark
25
france
19
germany
3
holland
3
norway
115
russia
2
sweden
1
usa
10

 

8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy J7RH September 30 2006, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
8902j43a.jpg (64885 bytes)Great Black-backed Gull (Larus marinus) 1cy J33Y September 26 2007, Boulogne-sur-Mer, France (50.42 N - 01.34 E). Picture: J-M Sauvage.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JM06 September 30 2006, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JA697 September 06 2008, Westkapelle, The Netherlands. Picture Johannes Luiten & Ies Meulmeester.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JA725 September 04 2009, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
gbbgGreat Black-backed Gull (marinus) 1cy JA804 September 28 2012, Boulogne-sur-Mer, NW France. Picture: Jean-Michel Sauvage.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JE676 September 24 2010, Westkapelle, the Netherlands. Picture: M v Kleinwee.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JH837 September 20 2010, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JP132 September 21 2011, Westkapelle, the Netherlands. Picture: M v Kleinwee.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy JP149 September 18 2011, IJmuiden, The Netherlands. Picture: Jan Zorgdrager.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JT793 1cy: September 27 2014, Ter Heijde, the Netherlands. Picture: Caroline Walta.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) 1cy 25C September 24 2007, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 1cy NOS 3020847 September 23 2011, Scheveningen, the Netherlands.
2121gbbgad.jpg (50050 bytes)Great Black-backed Gull (Larus marinus) 3U4 September 2013 & May 2014, New York & Whiting. Picture: Brad Carlson & Amar Ayyash.
2121gbbgad.jpg (50050 bytes)Great Black-backed Gull (Larus marinus) 7J1 1CY, September 15 2013, Rye Harbor, New Hampshire. Picture: Steve Mirick.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 1VA 1st cycle (1CY-2CY), September 2013 - January 2014, Dublin, Ireland. Picture: Graham Prole.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 1cy: September 23 2011, Scheveningen, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 1cy: September 23 2011, Scheveningen, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 1cy: September 23 2011, Scheveningen, the Netherlands.
6469.jpg (86554 bytes)Great Black-backed Gull (Larus marinus) 1cy: September 30 2001, Le Portel - Boulogne sur Mer, France (50.42 N - 01.34 E).