Lesser Black-backed Gull (graellsii & intermedius)

(last update: 14-11-2017 )

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LBBG rings

lbbg 1cy May
lbbg 1cy June
lbbg 1cy July
lbbg 1cy August
lbbg 1cy September
lbbg 1cy October
lbbg 1cy November
lbbg 1cy December

lbbg 2cy January
lbbg 2cy February
lbbg 2cy March
lbbg 2cy April
lbbg 2cy May
lbbg 2cy June
lbbg 2cy July
lbbg 2cy August
lbbg 2cy September
lbbg 2cy October
lbbg 2cy November
lbbg 2cy December

lbbg 3cy January
lbbg 3cy February
lbbg 3cy March
lbbg 3cy April
lbbg 3cy May
lbbg 3cy June
lbbg 3cy July
lbbg 3cy August
lbbg 3cy September
lbbg 3cy October
lbbg 3cy November
lbbg 3cy December

lbbg sub-ad January
lbbg sub-ad February
lbbg sub-ad March
lbbg sub-ad April
lbbg sub-ad May
lbbg sub-ad June
lbbg sub-ad July
lbbg sub-ad August
lbbg sub-ad Sept
lbbg sub-ad Oct
lbbg sub-ad Nov
lbbg sub-ad Dec

lbbg adult January
lbbg adult February
lbbg adult March
lbbg adult April
lbbg adult May
lbbg adult June
lbbg adult July
lbbg adult August
lbbg adult September
lbbg adult October
lbbg adult November
lbbg adult December

second calendar year: November

General

Nearly every large gull species in second winter exhibits one of the most variable plumages. In this respect, the LBBG is certainly no exception. At Westkapelle, the Netherlands (where most pictures were taken) most present adult LBBG (in late autumn and winter) originate from Scandinavia. Regarding second winter LBBG, the lack of sufficient individuals with rings makes us rather reserved to the identification on the level of subspecies. As can be read in the captions of the images, a few times we have tried to explain why a particular bird, in our opinion, could be intermedius. However, absence of such presumptions does not necessarily mean that the individual in question belongs to graellsii. Actually, experienced gull-enthusiasts may recognize more birds featuring characteristics of intermedius in this section.

Primary moult stage

The table below presents a primary moult score of November 06 2001 at Maasvlakte, the Netherlands. Throughout the summer months, from May to September, the primary moult scores in 2cy Lesser Black-backed Gulls remained very unpredictable, with much variation, as can be seen most obviously in the July Section. (Compare to e.g. 2cy Yellow-legged Gulls in France). But by early November, only a very small minority has not finished the primary moult (and therefore finish the complete summer moult, with all feathers now at least of second generation).

In the mean time, simultaneous with replacement of the primaries in summer, 2cy Lesser Black-backed Gulls from the Netherlands moult all the scapulars, wing-coverts, tertials and rectrices. In the July and August section the progress of this complete moult is described. By August, the complete moult in the wing-coverts is finished with replacement of the last central greater coverts (normally #6-8) and finally the feathers in the carpal edge (outer lesser coverts). As those last lesser coverts are replaced for second generation feathers, the partial autumn moult starts in 2cy birds only a few weeks after the complete moult during summer, again with the upper tertials and outer median coverts as can be found in several images in the August Section.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands. P1-P2 replaced for 3rd gen.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands. P1-P2 replaced for 3rd gen.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 09 2015, Utrecht, the Netherlands.

Lesser Black-backed Gull 2CY, November 09 2015, Utrecht, the Netherlands.

Timing and strategy of partial moult

The sequence and extent of this partial moult is quite consistent. The first signs of moult appear in the inner greater & inner median coverts and upper tertials, which are moulted in a  descendant order (from the body towards the wingtip).
The onset of moult in the outer median coverts overlaps with the start of the inner coverts and upper tertials, but on average it starts a few weeks later. Contrary to the inner median coverts, the outer and central median coverts are moulted in ascendant order (from the wingtip towards the body). This explains the old (second generation) 4th-6th visible inner median coverts, which are usually moulted in the final stage. The lower lesser coverts follow a less strict schedule and may be moulted 'randomly' as it seems. In the partial wing-covert moult, it is quite common to find birds leaving the inner most greater and median covert out of the sequence, starting with #2.

At the bottom of this page, a table is included to show roughly the stage of partial moult in early November in 2cy Lesser Black-backed Gulls. The exact sequence of the partial moult varies from one individual to another, but most 2cy birds will moult some of the following feathers in autumn: tertials, wing-coverts, scapulars and in a few cases tail-feathers. This was described already in the September section

It's hard to label all wing-coverts to exact generation. As can be seen in the May Section, the post-juvenile moult in especially intermedius can be very extensive, even including the tail-feathers. 
By November, the scapulars may have been moulted again to fourth generation feathers, although the pattern may still be not completely adult-like. Due to the considerable moult in the scapulars in 1cy birds in August-November, in 2cy birds in April-May (on the wintering grounds), in July and again in September, we exclude the scapulars from further analysis.
Many 1cy Lesser Black-backed Gulls moult the upper tertials and most of the inner wing-coverts to second generation in the post-juvenile moult, either starting on the breeding grounds or in a rapid moult in winter. All wing-coverts and tertials are moulted again in the complete moult in summer. In the partial autumn moult, wing-coverts (at least the inner greater and median coverts) and upper tertials are moulted to thirth generation feathers in most 2cy birds. 

Patterns in third generation coverts

The pattern of the new feathers vary from plain adult-like grey feathers to feathers hardly distinguishable from the old second generation feathers. Those feathers show a anchor pattern or barred pattern (dark brown to blackish) with a pronounced dark broad shaft-streak on a warm brown base (but the brown tone of these feathers will bleach to almost white with time). Some birds have an intermediate coloration: a plain grey base of the feather with a brownish upper half, an anchor pattern and a clear white fringe. 
Some  birds may look very advanced, almost similar to 3cy birds, after completion of the partial moult, with plain grey feathers in all the scapulars, the upper four tertials, the inner 10 or so greater coverts, all median and lower lesser coverts and all visible lesser coverts. In general: almost all grey upper-parts in these birds.

As in the October Section, 2cy Lesser Black-backed Gulls can be divided in three categories:

1. As can be read in the captions, some individuals look more 'advanced' in the moult of the upper-parts and wing-coverts. Actually, those 'advanced individuals' don't necessarily show an 'advanced moult stage' but rather show an 'advanced pattern on the feathers'. Quite some birds show a complete or almost complete greyish scapular and mantle region, a complete greyish median covert bar, combined with greyish inner greater coverts and single greyish tertials. On a whole, this gives a pretty 2nd summer-like appearance. From November onwards, over 90% of the 2cy LBBGs present at the Maasvlakte and Westkapelle show at least new inner greater and median coverts, with many (>60%) showing new central median coverts or completely new median coverts.

2. The exact same moult stage (i.e. amount of moulted feathers to 3rd generation) can be found in very brownish or variegated birds as well. Regardless their same moult stage, the look more 'immature, second generation-like', an impression created by the anchor or barred pattern on the new 3rd generation feathers.  It's the brown impression that gives these birds a less advanced look, but the actually moult timing is average. This partial autumn moult of e.g. median coverts has not been found in 3cy LBBG, seen at the same place and date.

3. The intermediate birds show a grey scapular region combined with patterned wing-coverts.

So far, we didn't find criteria to allocate these categories to sexes or geographical locations. Probably, "advanced looking individuals" can be found in any populations, though there is a slight tendency to name the "less advanced birds" from category 2 British graellsii as they often stand out as robust and strong individuals, unlike the average compact, smaller Scandinavian intermedius.

Tables 2cy November-December

2cy LBBG: November 6 2001, Maasvlakte, the Netherlands.
primary score: p8 new p9 new p10 new n: m:  
0 7 68 75 9,91
replaced median coverts: 0% 25% 50% 75% 100% n:
22 18 21 6 1 68
replaced greater coverts: 0% inner new* inner & outer new** n:  
37 27 4 68

n: total.
m: average.
*: the inner 1 to 4 greater coverts replaced.
**: the inner 1 to 4 greater coverts replaced, next 1 or 2 remained and 4 to 6 outer greater coverts replaced.

 

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2cy LBBG UK: graellsii
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Lesser Black-backed Gull graellsii F:270 2CY, September - November 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsiiARAY 2CY, November 21 2010, Madrid, Spain. Picture: Delfín González.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii T6TN 2CY, November 05 2008, Westkapelle, the Netherlands.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii A:D61 2CY, November 15 2016, Torreira beach, Aveiro, Matosinhos, Portugal. Picture: José Marques.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii A:D90 2CY, March & December 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii T:57C 2CY, December 31 2013, Landfill VRSU de Colmenar Viejo, Madrid, Spain. Picture: Delfín González.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii JN7T 2CY, June - December 2013, Koksijde, Belgium. Picture: Peter Adriaens.
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2cy LBBG France:
graellsii Dutch Intergrade
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Lesser Black-backed Gull graellsii 040N 2CY, December 17 2006, Madrid, Spain. Picture: Delfín González. Also seen as 2cy April.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii 042K 2CY, November 01 2007, Westkapelle, the Netherlands. Picture by Pim Wolf.
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2cy LBBG Belgium:
graellsii Dutch Intergrade
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Lesser Black-backed Gull graellsii RG.AR 2CY, December 29 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii RN.AU 2CY-3CY, November 2016 - March 2017, Aveiro, Portugal. Picture: José Marques.
2cy graellsii in October, ringed in Belgium. (123735 bytes)Lesser Black-backed Gull graellsii BLB L-106845 2CY, November 01 2004, Westkapelle, the Netherlands. Picture by Pim Wolf.
7576.jpg (71962 bytes)Lesser Black-backed Gull graellsii BLB L-..92.. 2CY, November 08 2001, Westkapelle, the Netherlands. Ringed in Belgium.
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2cy LBBG Netherlands:
graellsii Dutch Intergrade
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Lesser Black-backed Gull graellsii 9.5 2CY, November 15 2016, Torreira beach, Beira Litoral, Portugal. Picture: José Marques.
Lesser Black-backed Gull graellsii 9E 2CY, December 19 2009, Cambrils, Cataluña, Spain . Picture: Alberto Rodriguez.
Lesser Black-backed Gull graellsii SU 2CY, December 07 2008, Madrid, Spain. Photo by Delfín González.
Lesser Black-backed Gull graellsii YV 2CY, December 31 2008, Madrid, Spain. Photo by Delfín González.
Lesser Black-backed Gull graellsii JG 2CY, April 2008 - March 2009, Madrid, Spain. Picture: González & Martin.
Lesser Black-backed Gull graellsii GZ 2CY, November 23 2008, Madrid, Spain. Picture: Delfín González. Also seen as 3cy January.
Lesser Black-backed Gull graellsii J9 2CY, November 28 2010, Madrid, Spain. Photo by Delfín González.
E219a011101.jpg (68410 bytes)Lesser Black-backed Gull graellsii MS 2CY, November 04 2010, Westkapelle, the Netherlands.
E219a011101.jpg (68410 bytes)Lesser Black-backed Gull graellsii YALW 2CY, November 05 2010, Westkapelle, the Netherlands.
Lesser Black-backed Gull graellsii K.BJC 2CY-4CY, December 2015 - April 2016 & January - March 2017, Leixões harbour, Matosinhos, Portugal. Picture: José Marques.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii KDAC 2CY, November 12 2008,Westkapelle, the Netherlands.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii E471 2CY-3CY, December 31 2006, Madrid, Spain. Photo by Delfín González. Also seen as 3cy Febr.
E219a011101.jpg (68410 bytes)Lesser Black-backed Gull graellsii EE219 2CY, November 01 2001, Westkapelle, the Netherlands. Photo by Pim Wolf.
6464e557.jpg (90208 bytes)Lesser Black-backed Gull graellsii EE557 2CY, November 02 2002, Westkapelle, the Netherlands.
2cy graellsii in October, ringed in the Netherlands. (95974 bytes)Lesser Black-backed Gull graellsii C95E 2CY, November 05 2004, Amsterdam, the Netherlands.
2cy graellsii in October, ringed in the Netherlands. (123735 bytes)Lesser Black-backed Gull graellsii NLA 5.414.454 2CY, December 29 2005, Amsterdam, the Netherlands.
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2cy LBBG N Germany:
graellsii - intermedius
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1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii H328 2CY, Westkapelle, the Netherlands, November 05 2009. Also as 3cy.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii H278 2CY, December 31 2008, Madrid, Spain. Photo by Delfín González.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull graellsii H291 2CY, November 09 2008, Westkapelle, the Netherlands.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii H489 2CY, November 09 2008, Madrid, Spain. Photo by Delfín González.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii H560 2CY, November 16 2008, Madrid, Spain. Photo by Delfín González.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii H873 2CY, December 12 2010, Madrid, Spain. Photo by Delfín González.
1cy argenteus in November, ringed in Belgium. (25637 bytes)Lesser Black-backed Gull intermedius HE7E3 1CY-2CY, October 2015 & December 2016, the Netherlands & Portugal. Picture: Mars Muusse & José Marques.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull graellsii HV140 2CY, November 01 2014, Zeebrugge, Belgium. Picture: Peter Adriaens.
Lesser Black-backed Gull graellsii HXE54 2CY, December 04-11 2015, Matosinhos, Portugal. Picture: José Marques.
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2cy LBBG Denmark: intermedius
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juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull intermedius V423 2CY, November 22 2009, Madrid, Spain. Photo by Delfín González.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull intermedius VA4M 2CY, November 21 2010, Madrid, Spain. Photo by Delfín González.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull intermedius VT2E 2CY, November 28 2014, Katwijk, the Netherlands.
juvenile LBBG, ringed in the Netherlands.Lesser Black-backed Gull intermedius V1SA 2CY, December 13 2009, Madrid, Spain. Photo by Delfín González.
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2cy LBBG Norway: intermedius
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Lesser Black-backed Gull intermedius J221N 2CY, November 11 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques.
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unringed 2cy LBBG
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6437cy2.jpg (80865 bytes)Lesser Black-backed Gull 2CY, November 02 2015, Utrecht, the Netherlands.
6437cy2.jpg (80865 bytes)Lesser Black-backed Gull 2CY, November 09 2015, Utrecht, the Netherlands.
6437cy2.jpg (80865 bytes)Lesser Black-backed Gull 2CY, November 09 2015, Utrecht, the Netherlands.
Lesser Black-backed Gull 2cy, November 26 2000, Westkapelle, the Netherlands. Representative for local Dutch intergrades in 2cy.
Lesser Black-backed Gull 2cy, November 26 2000, Westkapelle, the Netherlands. P10 with small mirror.