3cy michahellis in
September can be recognized by the plain grey
upper-parts and coverts, often combined with some retained barred
wing-coverts, especially in the carpal edge and the lower tertials.
Most birds have finished the complete moult in the under-parts and
head, now showing much streaking in the crown, nape and ear-coverts.
The bare parts are typically less bright coloured than last summer
or as in adults,
now showing a brown-red orbital ring, often a dark hue in the iris, much black on the bill and still straw-yellow legs. An example of the average
September 3cy michahellis
can be found in the first
image, an individual ringed 074S with adult-like upper-parts, some barred wing-coverts in the
outer greater coverts, a pinkish base of the bill and much speckling
in the iris. This bird was ringed in summer 2000 in S France.
Although 074S shows some clear 3cy features, some birds may be very
advanced in moult, much resembling 4cy birds, as is demonstrated by 255S,
ringed on the same location as 074S. A very typical 3cy michahellis
can be found in the October Section: this
bird photographed on October 01 2001.
The table below shows the average primary moult score for 3cy michahellis
in September: about 9.0 at the end of the month. So, the average
bird only has to grow one primary to finish the complete moult,
which started last May.
details on differences between michahellis and cachinnans, see
e.g. the article by R. Klein & D. Gruber in Limicola, April
stage and pace of remiges and rectrices:
The complete moult started mid-May,
when 3cy birds dropped the innermost primary P1. By early July, the
average score has strongly increased: only P7-P10 are still old second
generation and the inner primaries are new. By August 01, the average primary moult score
is about P5. With this score, 3cy birds are two primaries behind compared to
As in adults, the gap between full-grown primaries and remaining old
primaries is about three feathers in general, or slightly more as the table in the July
section shows. This large moult gap is
typical for michahellis, and not found in e.g. Dutch argenteus.
By early August, 3cy michahellis has an average score P6
fully grown, so the majority of resting birds shows new primaries in
the folded wing. This score increases gradually during the month. We
have no late-August or early-September scores, but by the third
decade of September the primary moult score exceeded 8.0. The score
for the end of August must be about P7.
The score for late-September is 9.2 in two surveys totaling 56 individuals in NW France.
By the time P4 is fully grown, 2cy
birds normally start the complete moult in secondaries and rectrices.
The ordinary moult strategy in 3cy birds may be slightly later
(starting when P5 is fully grown. Note however that individual
variation may exist, particularly in 3cy michahellis
rectrices moult as this moult may follow an irregular pattern in
earlier months. The
partial spring moult has finished in June and a small minority of 3cy
have included some rectrices in this partial moult. Hence, it's not uncommon
to find 3cy birds showing plain white tail-feathers, in some birds
creating a 'blocked' tail pattern, prior to the complete
On average, the common sequence is centrifugal moult:
starting with the inner tail-feathers and continuing symmetrically
outwards to both outer feathers. The moult in the rectrices is
completed in September. New feathers are white with various amount
of black markings. Some individuals have a clean white tail. The new
feathers can be recognised by the fresh fringes and tips.
Secondary moult starts in early August. The images on the July page
birds with open wings illustrate that all outer secondaries are
still present. By early August, the outermost secondaries (S1 &
S2, at the division between secondaries and primaries) are normally
dropped individually, but the central secondaries are shed almost as
in small groups, creating large gaps of missing secondaries, nicely
illustrated by this flying 2cy
bird and this stretching 3cy
The secondary moult finishes with the replacement of the inner secondaries
(about S18), close to the tertials (which in fact are secondaries as
well). The completion of the secondary moult coexists with moment
that P8 is fully-grown. This is late-September in most individuals.
moult vs. partial moult
In the complete moult during the summer,
3cy michahellis moult all the scapulars, wing-coverts, tertials and
flight-feathers. The complete moult started in May, when P1 was dropped
and the complete moult will be finished when P10 will been replaced in
October. By August, the complete moult in the wing-coverts is finished
with replacement of the last central greater coverts and finally the
feathers in the carpal edge (outer lesser coverts). As those last
lesser coverts are replaced, 3cy michahellis start the
partial autumn moult. In this partial moult some wing-coverts and tertials
are included. It starts again with the upper tertials and outer median
coverts and is nicely illustrated by this
individual from October 01 moulting P8. The
outer median coverts are clearly missing.
3cy michahellis show a much larger individual variation in moult
stage than 2cy birds. (For instance: the same individual from October 01
with P7 fully-grown, while the average score for late-September is 9.2).
So its hard to generalize on partial moult stage in 3cy in September, and
it may be strongly related to the primary moult stage of an individual.
However, partial moult may start by the last week of August in advanced
birds. By late-September, the
innermost greater, median and lower lesser coverts and the upper tertials
have been replaced in the partial moult.
The partial moult in 2cy michahellis
is often more obvious and explained in the 2cy
michahellis section. See Topography
Section for explanation of feather tracts.
were done at resting and preening 3cy sub-adults (with at least
no white mirror at P10 and at least some obvious second summer feathers).
michahellis primary moult scores: Boulogne-sur-Mer, NW France, September 2001 & 2002.
3cy birds selected on bare part coloration, tail pattern, pattern on
inner secondaries and outer greater primary coverts. Scores of
longest fully grown new third generation primaries.
3cy, September 21 2002, Etaples (France).
P8 fully grown. This bird was recorded on the same spot in