Lesser Black-backed Gull (graellsii & intermedius)(last update:
|
||
lbbg 1cy May lbbg 2cy January lbbg 3cy Jan-April lbbg sub-ad Jan-April lbbg adult January |
second calendar year: January Normally, LBBG do not winter in the Netherlands, but depending on winter conditions some may stay in the most south-western point of our country at Westkapelle, Zeeland. Most LBBG present are believed to belong to the race intermedius originating from Denmark to Norway (Vest-Agder). Nevertheless, some local Dutch graellsii -of the type 'Dutch intergrade'- may stay during winter as well, as Dutch colour-ringed individuals showed in winter 2000/2001 at Westkapelle and IJmuiden, near Amsterdam (see distribution maps for locations). Post-juvenile moult in LBBGThe post-juvenile moult in large white-headed gulls in Europe is variable among the species. "The standard" post-juvenile moult is set by Herring Gull (Larus argentatus) and Great Black-backed Gull (L. marinus). These species have a rather restricted post-juvenile moult. Juvenile birds from southern populations normally replace scapulars before the end of the calendar year. They do not include any tertials, wing-coverts or flight feathers in this post-juvenile moult (about 1-2% do replace single wing-coverts; it's a matter of definition if this should be interpreted as 'moult', as it is often not symmetric in the wings). Birds from northern populations often remain in completely juvenile plumage, except for a few small upper scapulars that will be replaced for 2nd generation feathers. However, ringed birds with northern origin sometimes follow a southern moult timing as well. A few illustrations of this "Herring Gull standard" below: The gulls depicted above are all example birds with limited post-juvenile moult (no coverts, no tertials, no flight feathers), which is the standard in Herring Gull and Great Black-backed Gull. Two other taxa hatch slightly earlier in the season, and both have a more extensive post-juvenile moult: Caspian Gull (L. cachinnans) and Yellow-legged Gull (L. michahellis). Both species have all scapulars replaced by mid November (except for the odd retarded bird, or relatively late moulting subspecies e.g. L. m. lusitanius). By the end of the year, cachinnans and michahellis have all scapulars replaced, and many birds also replace wing-coverts and tertials in the post-juvenile moult of their hatch year. Moulting wing-coverts or tertials make these birds different from the Herring Gull standard. A few example birds below: Both Caspian and Yellow-legged Gull are early hatching and fletching species, in which the post-juvenile moult starts early in the season. The end of this post-juvenile moult is reached by mid-November. After this date, its normally only a low pace progress in scapular replacement that continues; there will be no new moult gaps in the wing-coverts nor in the tertials. This time schedule is important to remember when dealing with Lesser Black-backed Gull subspecies; western taxon graellsii can match to the schedule of michahellis (albeit slightly -4 weeks- later, but still before the end of the year), while Scandinavian taxa intermedius and fuscus are much later in post-juvenile moult commencement. In short, it is possible to observe 2CY graellsii and 2CY intermedius side-by-side in N Europe in May or June, both birds looking pretty much the same regarding feather replacement, but the wear in the fringes is completely different. Graellsii replaced wing-coverts early in the winter (October-November), while many intermedius moult these same feather tracts much later, in March-April. Consequently, intermedius looks much tidier and neat in June, where graellsii has a more bleached and worn plumage. There is a tendency to a west-northeast cline regarding extent of the post-juvenile moult. Many of the 2CY April graellsii (ringed birds) on this website show the standard Herring Gull post-juvenile moult: replaced scapulars, but retained juvenile wing-coverts, juvenile tertials and flight feathers. Some graellsii do look more advanced, like the last 2CY graellsii bird from April 27 in Dordrecht, but still most juvenile in its plumage. The group of ringed intermedius from April also includes some "standard Herring Gull moult strategies" birds, but many birds show more advanced moult. Midway this spectrum are birds with upper tertials replaced, and most of the (visible) inner wing-coverts replaced for 2nd gen, as illustrated by the intermedius 2CY bird from May 09 Simrishamn. The far end of the spectrum contains birds illustrated in the table below: all scapulars replaced, most wing-coverts replaced, all rectrices replaced and even a variable number of secondaries moulted to 2nd gen. From the data on ringed birds, it appears there is a large variation in moult extent in intermedius. This large variation is shared by the eastern cousin 'heuglini'. Visa Rauste photographed a large group of 2CY Lesser Black-backed Gull heuglini, in June in N Russia. The overall appearance and moult strategy in heuglini is remarkable similar to that of intermedius. Except for one (key) difference: quite commonly heuglini include some to many primaries in the post-juvenile moult on the wintering grounds (moult prior to migration). The table below shows a selection of the most advanced 2CY spring intermedius type of birds recorded in western Europe, together with 2CY heuglini birds from the group photographed by Visa. All birds observed in June.
|
. LBBG from the U.K.: 2cy graellsii . |
Lesser Black-backed Gull graellsii F:046 1CY-4CY, December 2014 - January 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 8C1:C 1CY-2CY, October 2016 - January 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG A6YD January 02 2011, Madrid, Spain. Picture: Delfín González. | ||
Lesser Black-backed Gull graellsii 1CP5 2CY, January - March 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 5CS5 1CY-3CY, December 2014 - July 2016, Praia de Mira, Coimbra, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 5FK9 1CY-2CY, November 2016 - January 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 6CL9 2CY, January 10 2015, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 8FJ4 2CY, January - March 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 9FF3 2CY-3CY, January 2016 - March 2017, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG 0H9 January & March 2010, Madrid, Spain. Picture: González & Frías. | ||
LBBG 1K8 January 06 2010, Madrid, Spain. Photo by Delfín González. Also seen in September 2009. | ||
LBBG B:H January 21 2007, Madrid, Spain. Picture: Delfín González. | ||
Lesser Black-backed Gull graellsii K+G 2CY, January 17 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii K+W 1CY-2CY, October 2016 - January 2017, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG M+Z January 13 2013, Madrid, Spain. Picture: Delfín González. | ||
LBBG F:G January 20 2008, Pantín, Spain. Picture: Antonio Gutierrez. | ||
LBBG AJ.AH January-March 2009, Madrid, Spain. Photo by Delfín González. | ||
LBBG DD.DC January 04 2013, Madrid, Spain. Photo by Delfín González. | ||
Lesser Black-backed Gull graellsii NLNB 2CY, January - March 2015, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii RK.RH 1CY-2CY, December 2016 - January 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
. LBBG from France: 2cy graellsii . |
||
Lesser Black-backed Gull graellsii 3:DNR 1CY-2CY, September - March 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG 015K January 04 2007, La Séguinière, W France. Picture: Alain Fosse. | ||
LBBG 450N January 30 2008, Cedeira, Spain. Picture: Antonio Gutierrez. | ||
LBBG R:N3N January 13 2013, Madrid, Spain. Picture: Delfín González. | ||
Lesser Black-backed Gull graellsii R:V7N 1CY-3CY, December 2014 - October 2016, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii R:X0R 1CY-2CY, December 2014 - January 2015, Leixões Port, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii R:X5J 2CY, January 02 2015, Matosinhos, Portugal. Picture: José Marques. | ||
. LBBG from Belgium: 2cy graellsii "Dutch intergrade" . |
||
Lesser Black-backed Gull graellsii A.K0P 2CY, January 13 2017, Leixões harbour, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG TCAC 1cy-2cy, December 2011 - February 2012, Madrid, Spain. Picture: Delfín González. | ||
LBBG URAR January 12 2013, Madrid, Spain. Picture: Delfín González. | ||
. LBBG from the Netherlands: 2cy graellsii "Dutch intergrade" . |
||
Lesser Black-backed Gull graellsii X||9 2CY, January 14 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 22 2CY, January & October 2016, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii 9Y 2CY, January 06 2017, Leixões harbour, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii J3 2CY, January -June & October 2016, Douro River Estuary, Porto, Portugal. Picture: José Marques. | ||
LBBG 67 January 05 2009, Madrid, Spain. Picture: Delfín González. | ||
LBBG 82 January 01 2009, Madrid, Spain. Picture: Delfín González. | ||
Lesser Black-backed Gull graellsii K.BJL 2CY & 4CY, January 2015 & May 2017, Quarteira, Portugal & Texel, the Netherlands. | ||
. LBBG from the N Germany: 2cy transition graellsii - intermedius . |
||
LBBG H077 January 26 - February 03 2009, Champteussé-sur-Baconne, SW France. Picture: Alain Fosse. | ||
Lesser Black-backed Gull graellsii HAE66 2CY, January 14 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii HAL25 2CY, January 06 2017, Leixões harbour, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii HE3E9 2CY-3CY, January 2016 & January - March 2017, Leixões harbour, Matosinhos, Portugal. Picture: José Marques. | ||
Lesser Black-backed Gull graellsii HEHK7 2CY, January 02 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG H150 January 11 2009, Madrid, Spain. Picture: Delfín González. | ||
. LBBG from Denmark: 2cy intermedius . |
||
LBBG V023 January 11 2009, Madrid, Spain. Picture: Delfín González. | ||
LBBG V797 January 03 2010, Madrid, Spain. Picture: Delfín González. | ||
Lesser Black-backed Gull intermedius V.SN0 2CY, January 13 2017, Matosinhos beach, Matosinhos, Portugal. Picture: José Marques. | ||
. LBBG from S. Norway: 2cy intermedius . |
||
Lesser Black-backed Gull intermedius J221N 2CY, January-April & November 2016, Matosinhos Beach, Matosinhos, Portugal. Picture: José Marques. | ||
LBBG JR5X January 13 2013, Madrid, Spain. Photo by Delfín González. | ||