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 November

1st cycle vs 2nd cycle birds.

In some respect, especially general coloration, birds in 2nd cycle may resemble 1st cycle birds. Ageing birds often is a first step to correct identification, and therefore it is important to pay attention to subtle details.

marinus 1st cycle (1CY) JJ77 November 24 2006, Boulogne-sur-Mer, France (50.44 N - 01.35 E). Picture: Mars Muusse. Still almost completely juvenile, just single scapulars replaced.
1. juvenile scapulars have broad dark centres with notched fringes, lacking anchor patterns and sub-terminal lines.
2. juvenile primaries are pointed, not with a rounded tip.
3. all tertials are juvenile, the pattern as on the juvenile scapulars, lacking anchor patterns.
4. homogeneous wing-covert panel regarding patterns and condition of feathers.
5. secondaries with extensive dark centres and simple white line at tips.


marinus 2nd cycle (2CY) J1MV October 15 2008, Boulogne-sur-Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage. The overall coloration much resemble 1st cycle birds. However, the scapulars are different in pattern, and tehre are no feathers anymore with the brown centre and notched fringes. Also note:
1. rounded tips of 2nd gen primaries.
2. fresh 3rd gen upper tertials; although again somewhat similar in pattern to 2nd gen feathers, it obviously shows a sub-terminal line.
3. recently replaced inner greater coverts, with buffish tone and sub-terminal line; these are now 3rd generartion feathers.
4. 2nd gen secondaries show dark centres and pale tips, but now have much vermiculation at the edges.
5. old central median coverts, replaced last summer (to 2nd gen) and now contrastingly patterned white-brown, lacking buffish tones that are present in adjacent feathers.
6. recently replaced outer median coverts, with buffish tone and sub-terminal line; these are now 3rd generartion feathers.


marinus 1st cycle (1CY) JA697 September 06 2008, Westkapelle, The Netherlands. Picture: Ies Meulmeester. Juveniles show a neat plumage; all feathers of approximately the same age, except for the replaced scpaulars.


marinus 2nd cycle (2CY) J170W October 31 2012, Neeltje Jans, Zeeland, The Netherlands. Pictures: Pim Wolf. Tail with extensive fine spotting and mirror on P10 in most 2nd cycle marinus, reflecting already the extensive pale area found in later ages.

gbbgGreat Black-backed Gull (L. marinus) 2cy JH7P November 08 2006, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (L. marinus) 2cy J78Z November 10 2008, Westkapelle, The Netherlands. Picture Ies Meulmeester & Thomas Luiten.
8471j52c.jpg (85052 bytes)Great Black-backed Gull (L. marinus) 2cy JA609 November 07 2009, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
1598.jpg (74227 bytes)Great Black-backed Gull (L. marinus) JX260 2cy, November 01 2013, Boulogne sur Mer, France. Picture Jean-Michel Sauvage.
1598.jpg (74227 bytes)Great Black-backed Gull (L. marinus) 75L 1cy-2cy, November 2012 & November 2013, Boulogne sur Mer, France. Picture Jean-Michel Sauvage.
1598.jpg (74227 bytes)Great Black-backed Gull (L. marinus) NOS 337783 2CY August & November 2013, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (L. marinus) 2cy NOS 360820 November 25 2006, Boulogne/Mer, N France.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (L. marinus) 2cy RUM ES 008270 November 23-28 2011, Scheveningen, the Netherlands.

7095jp36.jpg (66909 bytes)Great Black-backed Gull (L. marinus) 2cy NLA 6.125.594 November 25 2012, Boulogne sur Mer, France (50.44 N - 01.35 E). Picture Jean-Michel Sauvage.
7095jp36.jpg (66909 bytes)Great Black-backed Gull (Larus marinus) 1A9:C 2CY, November 02 2013, Bullock Harbour, Dublin, Ireland. Picture: Graham Prole.