second
calendar year: June
Last update of
this page: 27-09-05 17:06
First
summer (2cy) LBBG can be classified in 3 categories. In the 2cy
LBBG May section,
we give details about this classification, based on research done last
years. Of course, the classification for May applies to June as well. In year 2001, we tried to get more information about the extremes of these
classes, especially regarding moult strategy and moult pace.
First type LBBG (local
typical 2cy) in June:
The under-parts and head are patterned with bold markings
on a dirty base. The partial spring moult involves head and under-parts.
By
June, birds show neat streaking on head feathers, combined with abraded
under-parts (often the vent and flanks).
The scapulars may have been moulted last autumn (as early as
September) to anchor patterned second generation feathers. By June, these
may be replaced again and the new pattern is largely unpredictable. They
may appear adult-like grey or brown-grey, often with a pronounced dark
shaft. But the third generation feathers may also show an almost similar
pattern as the second generation feathers, again with anchors or barring.
Some birds may require their first renewed second generation coverts as late as June. Fresh feathers can be recognized by the
white fringe.
The juvenile wing-coverts are shed rapidly
and new second generation coverts start growing. In some
individuals, complete covert-rows have been shed and the new feathers grow
simultaneously.
Again, the pattern shows barring or anchors. If the coverts were not moulted on the wintering ground,
moult starts
with the median covert row, combined by a few inner greater coverts and
randomly some lesser coverts (though often in the inner part of the
lessers). Normally, this first type
LBBG has some remaining juvenile coverts in the carpal edge (outer lesser coverts). The tail is still largely black-brown and
the present rectrices are nearly always juvenile,
though central rectrices are shed now. The bill is mostly blackish with only a slightly paler
base. Legs are pink.
All 2cy LBBG show active primary-moult in the inner primaries in
the first week of June. On average, towards the end of the month, P4 is
growing and P6 is shed. Second
& third type LBBG in June: These
types show a short neck, small rounded head, fine and short bill, short
legs (especially tibia) creating a delicate and compact appearance, in
some individuals pronounced by the relatively short primary-projection.
Also, plumage and timing of moult in wing-coverts and tail-feathers on average
are different from the first type. The first type LBBG start moulting coverts and scapulars at a high pace and especially the primary
moult may be more advanced than in the second and third type. We
treat the second and third type together, because in June
the differences between these two become less obvious as under-parts become
white and the exact pattern of scapulars and coverts is hard to detect on
the abraded feathers. As said in the 2cy LBBG May Section, these types
already replace scapulars and many wing coverts on the wintering grounds.
By June, the pattern gets lost and the fringes get worn. 2cy LBBG
belonging to these types start growing third generation coverts
now. As mentioned before, third generation coverts may resemble second generation coverts in pattern. Here, in these two types, the
third generation
coverts are often adult-like plain dark-grey (sometimes with an all-black
central wedge), unlike the bared or anchored 2nd generation
feathers.
Tail-feather moult
The number of moulted rectrices in the winter-quarters is highly
variable and subsequently we find large variation in June.
Advanced individuals show a complete second generation tail, while
others return in a clearly suspended moult-stage. In the
winter-quarters, many individuals do not proceed the moult of the
rectrices in a descendant sequence, since migrating birds in spring really
show every conceivable moult-stage (e.g. R5-6 second generation,
while R1-4 are still juvenile, etc).
Some birds do not show fully-grown rectrices, but it is at least not usual to
find a tail in active moult by May and early June. Apart from
the obvious fresh white tips, the pattern of the second generation
rectrices
is mostly juvenile-like, but the darker parts are pure black and the
pattern is more vermiculated. However, birds with for example a partially
white R2, a nearly complete black R3 and with a R4 showing much white, are
common. A small minority shows only very little black on the second generation tail-feathers.
The renewed upper-tail coverts are complete white or with some sparse
black barring on a white base.
Wing-covert moult
The wing-covert moult has mainly been suspended prior to migration, with
in most cases a generation contrast between the inner and outer coverts.
This especially applies to the greater coverts, which often show a mix of
juvenile and 2nd generation coverts, where tertials and median
coverts are often already renewed. The moult-stage of lesser coverts is
more advanced than the greater coverts, but especially 'upper' lesser
coverts are less advanced than the tertials and median coverts. Once
returned, many birds start shedding complete covert bars and grow new
feathers simultaneously.
Primary moult
The onset of the primary moult in second and third type
2cy LBBGs in early summer is on average slightly later (1-2 weeks) than in
typical first types. Additionally, the individual variation is
more pronounced, with e.g. in the third week of June, birds with
only P1-2 missing and birds which already shed P7. However, in
comparison with the first type, differences in timing of primary moult is
usually not significant.
Tables
Primary
moult score of 2cy LBBG June 26 2003, at Dannes gravel pit, NW
France (50.42N,01.34E). |
. |
no new |
P1 fg |
P2 fg |
P3 fg |
P4 fg |
? fg |
n: |
P3-P10 |
1 |
- |
- |
- |
- |
1 |
2 |
P4-P10 |
- |
- |
- |
- |
- |
3 |
3 |
P5-P10 |
- |
- |
1 |
- |
- |
5 |
6 |
P6-P10 |
- |
- |
4 |
4 |
- |
9 |
17 |
P7-P10 |
- |
- |
1 |
2 |
5 |
4 |
12 |
n: |
1 |
- |
6 |
6 |
5 |
22 |
40 |
n =
40; m old
P = 5.2; SD old P = 1.10.
P6-P10 =
P6-P10 are still old and present.
? fg = fully grown not known. Often referring to sleeping birds with
folded wings, so fully grown primary score most probably P6 or less.
fg = fully grown. In our field surveys, a primary is 'fully grown'
when it exceeds the previous feather in the folded wing. Actually,
such 'fully grown' feathers may have to grow a little, but under
field circumstances, it's very difficult to find out if the waxy
sheath, which is the standard measurement for fully grown primaries,
is still present. |
|
First
Type |
2cy
LBBG E528
June 13 & 14 2002, Boulogne-sur-Mer, France (50.42N,1.34E).
P4 is juvenile, P2 is growing. The tail is juvenile. |
2cy
LBBG
C95E
June 26 2004, Amsterdam, the Netherlands. A bird ringed left red C95,
right yellow E. |
2cy
LBBG 5.179.990
June 12 2005, Amsterdam, the Netherlands. Pullus born near Amsterdam. |
2cy
LBBG 5.412.311
June 15 2005, Amsterdam, the Netherlands. Pullus born in IJmuiden. |
2cy
LBBG FD
June 26-28 2003, Boulogne-sur-Mer, France (50.42N,1.34E).
Mint-green ring from Britain. |
Photo 1:
LBBG 2cy, June 26 2001, Bergen op Zoom, the Netherlands. The
ordinary Dutch LBBG with very much streaking on the under-parts and on the
head. |
Photo 2:
LBBG 2cy, June 30 2001, IJmuiden, the Netherlands. LBBG which completed the median covert
moult. |
Photo
3: LBBG 2cy, June 17 2001, Naaktstrand Maasvlakte, the Netherlands.
Many 2cy LBBG start moult of the central and outer median coverts, once
arrived from the wintering grounds. |
Photo
1279: 2cy LBBG, June
14 2002, Boulogne-sur-Mer, France (50.42N,1.34E).
P7 is still old. The dark 'shadow-print' of P6 is still visible on
P7. |
1639:
LBBG 2cy, June 18 2002, Vuurtorenvlakte - Maasvlakte, the
Netherlands. |
1598:
LBBG 2cy, June 17 2002, Dintelhaven Maasvlakte, the Netherlands.
Moulting the central and outer median coverts. |
1604:
LBBG 2cy, June 17 2002, Dintelhaven Maasvlakte, the Netherlands.
Moulting the central and outer median coverts. |
1789:
LBBG 2cy, June 24 2002, Papegaaienbek - Maasvlakte, the
Netherlands. |
1813:
LBBG 2cy, June 24 2002, Papegaaienbek - Maasvlakte, the
Netherlands. |
Second
Type |
2cy
LBBG
F40E
June 30 2005, Amsterdam, the Netherlands. A bird ringed left red F40,
right yellow E. |
2cy
intermedius J7N5 June
28 2003, Boulogne/Mer, NW France. An intermedius
ringed last year in Norway. |
2cy
LBBG 8106930
June 12 2005, Amsterdam, the Netherlands. From Sweden. |
Photo
4: LBBG 2cy, June 30 2001, IJmuiden, the Netherlands. Very
advanced bill coloration. P4 is full-grown, P5 is growing and P6 has
been shed. |
Photo
5: LBBG 2cy, June 26 2001, Bergen op Zoom, the Netherlands. New feathers are plain grey,
very dark, indicating this is probably a 2cy intermedius. |
Photo
6: LBBG 2cy, June 17 2001, Naaktstrand Maasvlakte, the Netherlands.
Some 2cy birds grow very dark plain grey median coverts and lower
scapulars. |
Photo
7: LBBG 2cy, June 26 2001, Bergen op Zoom, the Netherlands. Some
2cy LBBGs moult the median coverts as one row. Old scapulars appear plain
grey-brown.
|
1634:
LBBG 2cy, June 18 2002, Vuurtorenvlakte - Maasvlakte, the
Netherlands.
|
1641:
LBBG 2cy, June 18 2002, Vuurtorenvlakte - Maasvlakte, the
Netherlands.
|
1672:
LBBG 2cy, June 18 2002, Papegaaienbek - Maasvlakte, the
Netherlands.
|
Third
Type |
2cy
intermedius JXU7, June
18 2002, Papegaaienbek - Maasvlakte, the Netherlands. An intermedius
ringed last year in Norway. |
Photo
1279: 2cy
intermedius, June
14 2002, Boulogne-sur-Mer, France (50.42N,1.34E).
A pale head and very dark third generation scapulars. |
Photo
8: LBBG 2cy, June 17 2001, Naaktstrand Maasvlakte, the Netherlands.
All the second generation
upper parts of a simple pattern: plain brown-grey with a pronounced
shaft-streak. |
Photo
2033: 2cy
intermedius, June
26 2003, Boulogne-sur-Mer, France (50.42N,1.34E).
All secondaries moulted to 2nd generation. |
Photo
2172: 2cy
intermedius, June
26 2003, Boulogne-sur-Mer, France (50.42N,1.34E).
All primaries moulted to 2nd generation, possible fuscus. |
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