(2
images) Herring
Gull 90A34157
2cy (argentatus),
July 16 2003, Tampere,
Finland (61.31N,
23.43E).
A 2cy argentatus, ringed in Sweden
90A34157. Ringed as 2cy on 8 April 2003 at Malmö, Pildammsparken, Sweden (55.35N 13.00E),
so no certain origin. The complete moult is well underway with
most wing-coverts and the inner primaries moulted to second generation.
Primary P7 has been dropped and P8-P10 are still juvenile. P1-P4 are fully
grown second generation flight-feathers. All tail-feathers are still present.
Most tertials and the wing-coverts are replaced for second
generation feathers. The three upper tertials have been replaced and
the lower tertials are still juvenile. One inner greater covert is still
juvenile (probably #5), while the central greater coverts are missing. The
new greater coverts grown in descendant order, from the outer-wing
inwards, as is the common sequence. The gap in the median covert row is
just closed, with the last replaced feathers still buffish tinged. Most juvenile wing-coverts
can be found in the upper row of lesser coverts.
Fresh scapulars can be found in the rear lowest scapulars (probably
moulted to second generation as these are the last in line in the common
scapular moult sequence) and in the upper scapulars (probably replaced for
third generation feathers). Again, the fresh upper scapulars look very
second generation like. The fresh scapulars strongly contrast with
the adjacent old abraded second generation feathers, not as much in
pattern but in wear and tear.
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'. |
|