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(2
images) Herring
Gull HT-237.7xx
2cy (argentatus),
July 15 2003, Tampere,
Finland (61.31N,
23.43E).
A 2cy argentatus, ringed
HT-237.7xx. The complete moult is well underway with most wing-coverts and
the inner primaries moulted to second generation. Primary P8 has been
dropped and P9-P10 are still juvenile. P1-P6 are fully grown second
generation flight-feathers.
Most tertials and the wing-coverts are replaced for second generation
feathers. The upper tertials have been replaced and the lower tertials are
still juvenile. The gap in the central greater coverts is almost closed.
The new greater coverts grown in descendant order, from the outer-wing
inwards, as is the common sequence and the gap is closed at about greater
covert #6-8. Some juvenile wing-coverts can be found in the upper row of
lesser coverts.
Fresh scapulars can be found in the lower scapulars (probably replaced for
third generation feathers). Again, the fresh scapulars look very second
generation like.
By July, the warm brown tones of the first moulted
second generation feathers
(inner greater coverts and inner median coverts) are faded to
plain white, leaving a contrasting barred pattern on the wing-coverts. On
average, 2cy argentatus is more contrastingly patterned than same
aged 2cy argenteus, especially regarding the pattern on the central
greater coverts. However, some argentatus are distinct "washed
out" brown, showing the common vermiculated pattern of 2cy argenteus.
The
last moulted coverts are the central greater coverts and outer lesser coverts, replaced by
mid-August. From mid-August onwards, 2cy argentatus start the partial autumn
moult, starting again to drop the upper tertial and inner greater and
median coverts.
In the tables below, the primary moult
scores of 2cy July argentatus in Finland can be read:
Primary
moult score of 2cy argentatus Herring Gull, at Tampere
landfill, Finland (61.33N,
23.59E) on July 10 2003. |
. |
P4
fg |
P5
fg |
P6
fg |
P7
fg |
?
fg |
n: |
P6-P10 |
- |
- |
- |
- |
- |
- |
P7-P10 |
5 |
4 |
- |
- |
6 |
15 |
P8-P10 |
1 |
54 |
6 |
- |
13 |
74 |
P9-P10 |
- |
11 |
34 |
- |
2 |
47 |
P10
old |
- |
- |
1 |
1 |
- |
2 |
n: |
6 |
69 |
41 |
1 |
21 |
138 |
n
= 138; m old P = 2.7; SD old P = 0.67.
Survey at Tampere, landfill, in resting group at 'the saddle',
about 200 2cy Herring Gulls, probably 100% argentatus.
P6-P10 = P6-P10 are still old and present.
? fg = fully grown not known. 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. |
Primary
moult score of 2cy argentatus Herring Gull, at Tampere
landfill, Finland (61.33N,
23.59E) on July 13 2003, 15:00 h. |
. |
P4
fg |
P5
fg |
P6
fg |
P7
fg |
?
fg |
n: |
P6-P10 |
- |
- |
- |
- |
1 |
1 |
P7-P10 |
2 |
- |
- |
- |
4 |
6 |
P8-P10 |
- |
26 |
6 |
- |
18 |
50 |
P9-P10 |
- |
20 |
52 |
1 |
5 |
78 |
P10
old |
- |
- |
5 |
3 |
- |
8 |
n: |
2 |
46 |
63 |
4 |
28 |
143 |
n
= 143; m old P = 2.4; SD old P = 0.69.
Survey at Tampere, landfill, in resting group at 'Bio I'. |
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