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 March

Description of 1st summer plumage

First-summer (Mar-Aug) as first-winter, but head and underparts generally whiter. Mantle, back and scapulars grey with black subterminal bars and shaft-streaks. Upperwing and tail paler with wear. Bill black with smudgy, greyish- or fleshy-tinged base and pale tip to both mandibles. Eye dark. (source: Malling Olsen, K. & Larsson, H. 2004 Gulls of Europe, Asia and North America. London: Christopher Helm).

Moult in summer months.

The above description from Malling Olsen may be true for birds in March and April, but 2CY Great Black-backed Gulls in the summer months are obviously different from first-winter plumage birds.
Great Black-backed Gull is an early moulting species, at least that's what birds show that stay in NW France along The Channel coast and moult timing may even start earlier than 2CY Yellow-legged Gull michahellis (see tables in 2CY May section for marinus, michahellis and argentatus). New 2nd generation feathers may superficially resemble the old and worn juvenile feathers in pattern (transversal barring), but they are very fresh, especially visible at the fringes and the tips, and the base tone is warm buffish or pale brown rather than the silvery white tones in juvenile feathers, Only after several weeks these warm toned 2nd gen feathers will turn paler as well and become more contrasting again.

In early summer there is an obvious difference between fresh warm toned 2nd gen feathers and old bleached juvenile feathers, sometimes resulting in a messy looking bird, also due to missing feathers creating moult gaps in the covert rows. Such birds look different from first winter birds.
Later in summer (July-August) the process of complete moult is very obvious in the outer primaries and in this respect birds of course look very different from first winter birds.


Larus marinus JY481 2CY, February 10 2013, Boulogne-sur-Mer, France (Jean-Michel Sauvage). Classic late winter bird with most scapulars replaced, but wing-coverts and tertials still juvenile. Note pattern on juvenile central greater coverts: predominantly silvery white with widely spaced brown bars. Complete moult not started yet.


Larus marinus 3U4 2CY, May 27 2014, Whiting, USA (Amar Ayyash). Complete moult started early in this bird, with only P8-P10 old juevniel primaries in the left wing (P7 also still present in right wing). Note warm toned fresh 2nd gen median coverts and all central greater coverts missing. Messy looking bird.


Larus marinus 2CY, July 30 2014, IJmuiden, the Netherlands (Mars Muusse). P9-P10 old juvenile. Note vermiculated pattern on fresh 2nd gen greater coverts, different from the widely spaced bar pattern on juvenile greater coverts.


Larus marinus NOS 337783 2CY, August 14 2013, Boulogne-sur-Mer, France (Jean-Michel Sauvage). Complete moult in last stage with P7 fully grown and no old primaries left, resulting in short-winged appearance. Again, note vermiculated pattern on central greater coverts.


Larus marinus NOS 337783 2CY, November 06 2013, Boulogne-sur-Mer, France (Jean-Michel Sauvage). Same bird as previous image. Complete moult finished, note mirror on underside of P10. Compare to August, and notice a subsequent "partial autumn moult" has changed the plumage slightly, again fresh feathers appear in the wing panel. The upper tertial and innermost greater coverts GC1-2 have been replaced again; also new are median coverts MC2,10,11,13,15, and lower lesser coverts LLC1-3,6,8-12, and about 10x lesser coverts. Five of these fresh feathers indicated by red lines.

Tables:

Moult in 2cy March GBBG - ringed birds.
CODE  
US
LS
TOT SCAPS
nla 6038628 holland march
2
0
1
jw178 black denmark march
4
0
2
acx green usa march
3
1
2
3ct blue britain march
5
4
4
dkc 3M5206 denmark march
5
4
4
jy078 black denmark march
4
4
4
jz159 black denmark march
5
3
4
j3tr blue norway march
5
4
4
j43a black norway march
5
3
4
jp203 black norway march
5
4
4
jp287 black norway march
5
4
4
jp467 black norway march
4
4
4
ju137 black norway march
4
4
4
ju202 black norway march
5
4
4
nos 362917 norway march
5
3
4
1vr blue britain march
5
5
5
nla 7024244 holland march
5
5
5
j1ks blue norway march
5
5
5
j8k0 blue norway march
5
5
5
je1l blue norway march
5
5
5
jl90 black norway march
5
5
5
jm07 black norway march
5
5
5
ju116 black norway march
5
5
5

Note: nla 6038628 from Holland is the only bird in our sample (n=171) not ringed as pullus, but ringed in October in IJmuiden, Holland.

below: graph corresponding to data from table 1. n=23. Distribution of replaced scapulars in March 2cy 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).

below: Distribution of replaced scapulars for "Total scapular region" for months August in hatch year until commencement of first complete moult in April, n=228 only ringed birds. Classification in 6 classes, running from 0% (no 2nd gen scaps) to 100% (all scaps in a region have been replaced).

The group of birds which score 100% 2nd gen scapulars gradually grow; remember however that 1st cycle birds, especially in March-April, grown fresh upper scapulars again, most probably 3rd gen feathers (feather condition was not scored by us). Figures in the graph may be read reverse, the presence of juvenile feathers dimish through time.

8902j43a.jpg (64885 bytes)Great Black-backed Gull J43A (Larus marinus) 2cy: March 15 2003, Boulogne- sur-Mer, France (50.42 N - 01.34 E). Picture: J-M Sauvage.
2271je1l.jpg (54308 bytes)Great Black-backed Gull JE1L (Larus marinus) 2cy: March 25 2004, IJmuiden, the Netherlands (52.27 N, 4.33 E). Juvenile coverts and tertials. Almost all scapulars moulted to second generation. Note extensive black in tail.
2247j8k0.jpg (78638 bytes)Great Black-backed Gull J8K0 (Larus marinus) 2cy: March 25 2004, IJmuiden, the Netherlands (52.27 N, 4.33 E). Juvenile coverts and tertials. Almost all scapulars moulted to second generation.
8902j43a.jpg (64885 bytes)Great Black-backed Gull J3TR (Larus marinus) 2cy: March 22-24 2008, Boulogne-sur-Mer, France (50.42 N - 01.34 E). Picture: J-M Sauvage.
8902j43a.jpg (64885 bytes)Great Black-backed Gull J1KS (Larus marinus) 2cy: March 28 2008, Boulogne-sur-Mer, France (50.42 N - 01.34 E). Picture: J-M Sauvage.
2247j8k0.jpg (78638 bytes)Great Black-backed Gull JL90 (Larus marinus) 2cy: March 05 2007, IJmuiden, the Netherlands (52.27 N, 4.33 E). Single coverts replaced. Almost all scapulars moulted to second generation.
2247j8k0.jpg (78638 bytes)Great Black-backed Gull JM07 (Larus marinus) 2cy: March 12 2007, IJmuiden, the Netherlands (52.27 N, 4.33 E). Juvenile coverts and tertials. Almost all scapulars moulted to second generation.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JP203 2cy: February - March 2012, Vlissingen, the Netherlands. Picture: Albert de Jong & Floor Arts.
jz8mjan.jpg (127846 bytes)Great Black-backed Gull (Larus marinus) JP287 2cy: January & March 2012, IJmuiden, the Netherlands.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JP467 2cy: March 07 2013, Scheveningen, the Netherlands. Picture: Vincent van der Spek.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JU116 1CY-2CY, November 2014 & February - March 2015, IJmuiden, the Netherlands.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JU137 1st cycle, December 2014 & February - March 2015, IJmuiden, the Netherlands.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JU202 2CY, February & March 2015, IJmuiden, the Netherlands.
gbbg Great Larus marinus) 2cy JW178 March 04 2011, IJmuiden, the Netherlands.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JY078 2cy: March 02 2013, Groningen, the Netherlands. Picture: Klaas Heeres.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) JZ159 2cy, March 02 2015, IJmuiden, the Netherlands.
2046nos362917.jpg (60676 bytes)Great Black-backed Gull NOS 362917 (Larus marinus) 2cy: March 20 2004, IJmuiden, the Netherlands (52.27 N, 4.33 E). Resembling a juvenile.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (Larus marinus) DKC 3M-3206 2cy, March - May 2015, IJmuiden, the Netherlands.
2247j8k0.jpg (78638 bytes)Great Black-backed Gull NLA 6.038.628 (Larus marinus) 2cy: March 05 2007, IJmuiden, the Netherlands (52.27 N, 4.33 E). Juvenile coverts and tertials. Almost all scapulars moulted to second generation.
2247j8k0.jpg (78638 bytes)Great Black-backed Gull NLA 7.024.244 (Larus marinus) 2cy: March 02 2007, Lauwersoog, the Netherlands. Picture: Martin.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 1VR 2CY, March 30 2014, Howth, Ireland. Picture: Graham Prole.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 3CT 1st cycle (2CY), March 09 2014, Bray Harbour, Dublin, Ireland. Picture: Graham Prole.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 3EU 1st cycle (2CY), March 22 2014, Dublin, Ireland. Picture: Graham Prole.
9101.jpg (76303 bytes)Great Black-backed Gull (Larus marinus) ACX 1st cycle (2CY), March 14 2012, Woods Harbour, NS. Picture: Barrington Detachment.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 02 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: March 05 2007, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2cy: March 05 2007, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 16 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9149.jpg (76564 bytes)Great Black-backed Gull (Larus marinus) 2CY, March 17 2015, IJmuiden, the Netherlands.
9505gbbg.jpg (64061 bytes)Great Black-backed Gull (Larus marinus) 2cy: March 18 2003, Boulogne- sur-Mer, France (50.42 N - 01.34 E). A very powerful and enormous male, still with most feathers fresh juvenile. Probably from far northern Scandinavia or Russia.