sub-adult
(4+ calendar year): August
Last update of
this page: 03-04-04 23:06
Regarding
moult pace and strategy, sub-adults don't differ much from full adults.
Sometimes it's hard to age sub-adults correct, but on average, some or all
of the following features can be found in 4cy:
-
relatively
pale bare part coloration compared to full adults,
-
black
markings on the old rectrices, often isolated limited black spots near
the centre,
-
p10
with a small mirror, p9 lacking such a mirror and very small white
tips on the top of the outer primaries. By August, these tips are worn
away and the primaries are brownish, strongly bleached,
-
the
grey centres of the old secondaries show a brown hue and the tips are
abraded,
-
tertials,
outer greater coverts or outer lesser coverts (in the carpal edge)
show old adult-like feathers with a relative strong brown hue, obvious
much stronger than expected in full adult coverts.
Used
as a single characteristic, the evidence is not very convincing, but
individuals that combine these characteristics are probably 4cy or 5cy
birds.
|
sub-adult LBBG: Dutch intergrade |
LBBG
5cy ACAR, August
15 2003, Westkapelle, the
Netherlands. |
LBBG
5cy AMAK, August
01 2003, Zeebrugge, Belgium. |
LBBG
5cy BBAF , August
01 2003, Zeebrugge, Belgium. |
LBBG
5cy BLAR, August
01 2003, Zeebrugge, Belgium. |
LBBG
4cy L-87262, August
01 2003, Zeebrugge, Belgium. |
LBBG
4cy L-92876, August
01 2003, Zeebrugge, Belgium. |
sub-adult LBBG: unringed birds |
Photo
1: LBBG sub-adult, August 18 2001, Missouriweg
Maasvlakte, the
Netherlands. |
Photo
2: LBBG sub-adult, August 18 2001, Missouriweg Maasvlakte, the
Netherlands. |
Photo
3: LBBG sub-adult, August 22 2002, Missouriweg Maasvlakte, the
Netherlands. |
Photo
4: LBBG sub-adult, August 22 2002, Missouriweg Maasvlakte, the
Netherlands. |
arrested
moult in sub-adult LBBG |
Photo
5: LBBG
sub-adult, August
15 2003, Westkapelle, the
Netherlands. |