second calendar year: October


Last update of this page: 27-09-05 21:27

By October, all LBBG have left the colonies at the Maasvlakte (the Netherlands). In the pictures you can see what variation can be expected in 2cy LBBG by October. The variation seems large, but overall, 2cy LBBG may be classified in the following categories:

Category I

Those birds with second generation-like third generation feathers (click thumbnail #3). Second generation feathers often show characteristic anchor pattern, barring or deep notches in the fringe. Some 2cy birds replace these feathers in summer for more or less the same kind of feathers. Often the medians show barring or club patterns while the greater coverts have dense spaghetti like barring. This group of LBBG don't have grey feathers in the scapular region and in general there are no "adult-like" features. So far, we were not able to determine this type to geographical locations and probably such type of LBBG may turn up in both graellsii and intermedius (although there is a tendency to allocate them to graellsii). Several birds of this group originated from U.K. colonies, from Belgium and the bird in picture 1, ringed AH53 from northern Germany may be classified as "second generation-like third generation" as well. When birds of this type are heavily built, strong and robust in appearance, they may be mistaken for Yellow-legged Gulls (L. michahellis) in 2cy plumage, especially the ones without grey scapulars (but this is a rare case in October).

Category II

In October, 2cy LBBG move into the 'steady winter months' where moult is more or less suspended until early spring. However, some LBBG moult throughout the winter, at a lower pace. Others may appear very advanced and may show a 3cy spring plumage already by October, including the all grey adult-like scapular region and some grey median coverts. The lesser and greater coverts are still barred or with a club pattern. There are a few examples in the pictures, and the LBBG in picture 2, ringed in the Netherlands can be classified to this group. This category of LBBG is as hard to allocate geographically as the other group. 

Category III

And finally, there is a third -intermediate- group: those 2cy LBBG with grey scapulars combined by strongly patterned wing-coverts. As can be seen in the spring section of 3cy, this may be the plumage in which they return next year.

Partial moult in 2cy intermedius & graellsii

Although an undefined number of -predominantly intermedius- LBBG arrive from the wintering grounds with moulted wing-coverts and scapulars, the general idea is that, in line with large white-headed gulls of NW Europe, Lesser Black-backed Gulls start moulted from late April onwards: the complete moult. This complete moult includes all the wing-coverts, body-feathers, rectrices and of course the remiges. By September, the replacement of the last lesser coverts, inner secondaries and outer rectrices is finished, together with last to outer primaries.
By this time, the partial moult may start, including a various amount of wing-coverts, often a few upper tertials and in some birds a few of the rectrices are moulted again to third generation (all-white or almost all-white) tail-feathers. An example of such a bird with replaced rectrices can be found in photo 3
Partial moult in the wing-coverts is commonly seen in the row which was moulted first last summer: the median covert row. When the complete moult started last summer, the median coverts were dropped first and can look worn at the fringes by October, as several images show (especially in birds of category I, nicely illustrated by this 2cy bird in picture 13). Part of these worn median coverts are dropped again in autumn and replaced by third generation median coverts, which may vary in pattern: in some bird the new median coverts are plain grey, as is seen in 3cy LBBG or older birds. Images of 2cy LBBG with such grey median coverts can be found in category II. Other birds replace the median coverts for new third generation coverts with again a pattern of bars or anchors, much like the pattern found in second generation feathers. Representatives of this type of birds can be found in category I and II. Sometimes these new third generation feathers may be hard to detect, simply because they so much resemble the older second generation feathers. Easiest clue: compare the condition of the fringes. Note however that there is a short time overlap in the moult of the last lesser coverts (and sometimes the growing central greater coverts) and the start of the partial moult in the upper tertials and often in the median and lower lesser coverts.


Median coverts second generation.

Median coverts third generation.

Arrested primary moult in autumn

Arrested or, much better, suspended moult in the primaries is a rare phenomenon in 2cy LBBG graellsii and intermedius. The common moult stage in 2cy LBBG is P9 fully grown and P10 slightly shorter than P9, often at the length of P7 or P8 by the first week of October. Some birds are a little behind in moult with P8 the longest primary.
However, by October it's possible, though highly unusual to find 2cy LBBG still with old juvenile outer primaries. Occasionally such birds can be found while scanning flocks of migrating birds in NW Europe. The phenomenon of arrested or suspended moult seems to be more frequent in spring 3cy LBBG or in autumn sub-adult LBBG. There is a tendency to classify most of these birds in the group of intermedius, as the general characteristics of many these birds suggest: compact, small birds, short legs, short neck, small and slim bill; cute birds in general, somewhat reminiscent of Common Gulls in general jizz. 
2cy birds with suspended primary moult often show suspended moult or delayed moult in the secondaries. An example of suspended primary moult can be seen in image 5576.

2cy LBBG: 'Dutch intergrade'
2cy graellsii in October, ringed in the U.K. (75887 bytes)2cy LBBG GJ84559 October 08 2001, Westkapelle, the Netherlands. Picture Pim Wolf.
2cy graellsii in October, ringed in the Netherlands. (94174 bytes)2cy LBBG E532E October 05 2002, Dannes - Le Portel, NW France. A 2cy graellsii ringed at Maasvlakte, the Netherlands as pullus on July 01 2001.
2cy graellsii in October, ringed in the Netherlands. (95974 bytes)2cy LBBG C95E October 01 2004, Amsterdam, the Netherlands. Ringed at Maasvlakte, the Netherlands as pullus.
2cy graellsii in October, ringed in the Netherlands. (73572 bytes)2cy LBBG 5.361.744 October 22 2001, Westkapelle, the Netherlands. Ringed in the Netherlands.
2cy graellsii in October, ringed in the Netherlands. (109532 bytes)2cy LBBG 5.364.530 October 21 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
2cy graellsii in October, ringed in the Netherlands. (111593 bytes)2cy LBBG 5.412.032 October 01 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
2cy graellsii in October, ringed in the Belgium. (129132 bytes)2cy LBBG L-102569 October 07 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
2cy graellsii in October, ringed in the Belgium. (69954 bytes)2cy LBBG L-102780 October 21 2004, Westkapelle, the Netherlands. Picture Pim Wolf.
2cy graellsii in October, ringed in the Belgium. (91199 bytes)2cy LBBG L-106398 October 19 2004, Westkapelle, the Netherlands. Ringed in Belgium.

2cy LBBG: intermedius
2cy graellsii in October, ringed in Germany. (95677 bytes)2cy LBBG AH53 October 13 2001, Westkapelle, the Netherlands. A 2cy ringed AH53 on Helgoland, Germany.
2cy intermedius in October, ringed in Norway. (101059 bytes)2cy LBBG JU30 October 19 2002, Westkapelle, the Netherlands. A 2cy intermedius from southern Norway.
2cy intermedius in October, ringed in Norway. (97235 bytes)2cy LBBG 4236519 October 16 2004, Westkapelle, the Netherlands.

Category I

7122.jpg (92518 bytes)Nine images of 2cy LBBG, October 13 2001, Westkapelle, the Netherlands. Nine examples of rather brown 2cy LBBG, lacking the grey scapular region and grey medians.


Category II

7209.jpg (80424 bytes)Nine images of 2 cy LBBG, October 14 2001, Westkapelle, the Netherlands. Birds with a grey saddle and many grey third generation coverts. 


Category III

7334.jpg (76631 bytes)Seven images of 2 cy LBBG, October 22 2001, Westkapelle, the Netherlands. 2cy LBBG with (a few) grey scapulars but lacking the grey median covert bar.


PARTIAL MOULT IN 2CY

5541.jpg (78010 bytes)Photo 3: 2cy LBBG, October 05 2002, Dannes - Le Portel, NW France. Third generation rectrices in autumn.


ARRESTED MOULT IN 2CY

5576.jpg (76288 bytes)Photo 5576: 2cy LBBG, October 05 2002, Boulogne-sur-Mer, NW France. The outer primaries are still juvenile: moult will be suspended at P8.