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HG 1cy August
HG 1cy September
HG 1cy October
HG 1cy November
HG 1cy December
HG 2cy February
HG 2cy March
HG 2cy April
HG 2cy May
HG 2cy June
HG 2cy July
HG 2cy August
HG 2cy September
HG 2cy October
HG 2cy November
HG 2cy December
HG 3cy February
HG 3cy March
HG 3cy April
HG 3cy May
HG 3cy June
HG 3cy July
HG 3cy August
HG 3cy September
HG 3cy October
HG 3cy November
HG 3cy December
HG sub-ad Feb.
HG sub-ad March
HG sub-ad April
HG sub-ad May
HG sub-ad June
HG sub-ad July
HG sub-ad Aug.
HG sub-ad Sept.
HG sub-ad Oct.
HG sub-ad Nov.
HG sub-ad Dec.
HG adult February
HG adult March
HG adult April
HG adult May
HG adult June
HG adult July
HG adult August
HG adult September
HG adult October
HG adult November
HG adult December
2003, IJmuiden, the Netherlands (52.27N,04.33E).
A 4cy argenteus. The
scapulars and wing-coverts appear completely adult-like grey. The
primaries show a clear mirror on P10. Last autumn, this individual has
replaced the all-brown immature primaries for more adult-like primaries,
which show a white tip, a grey basal half and one or two mirrors (P9 and
P10). But still the size of the dark patches and the amount of black in
the outer primaries is more extensive when compared to adults: there is
often a broad dark sub-terminal band on P5 and a dark faint spot on the
outer-web of P4. The dark patches are not sharply demarcated as in adult,
but the dark outer-web gradually dissolves in the grey inner-web.
During summer, from June onwards, a
complete moult takes place in argenteus, bringing birds in
so-called "adult winter" plumage. As long as the old outer third
generation primaries are visible (until August), ageing as 4cy argenteus
is rather straightforward. From November onwards, 4cy argenteus
much resembles adult birds, except that the bare parts still show immature
feathers: the black bill-band is obvious, extending over both upper and
lower mandible. On average, this plumage develops a more pronounced winter
'hood' than in full adults: dense streaking on head, especially around the
eye and in the hind-neck. The upper-parts, wing-coverts and tertials
appear adult-like grey from 4cy October onwards. The fourth generation
tail-feathers are plain white.
The new fourth generation primaries are similar to the adult primaries,
although the primary tips may appear slightly smaller, but otherwise
similar in pattern: grey inner-wing and black outer-wing. Both P9 and P10
show a mirror. P5 shows small black sub-terminal markings,
concentrated on the outer-web as a clear-cut black angular spot and rarely
extending on the inner-web as a diffuse streak. There may be some black on
P4 as well. Adult argenteus show a different pattern in the outer
primaries, compared to northern argentatus. In argentatus,
especially from northern Scandinavia, the black marking on P5 is very
limited and diffuse or this is sub-terminal markings are completely
lacking on P5.
Argenteus has more black in the outer primaries, including a black
band on the top of p10 in most birds, dividing the tip from the mirror. If
the black sub-terminal band on P10 is broken, the outer-web of p10 still
shows black marking. Argentatus normally lacks sub-terminal
markings on the outer-web of P10.
The scapular coverts are plain grey, lacking white crescents. The tertials
show obvious white tips. The iris is yellow. The bill is yellow with a red
gonydeal spot confined to the lower mandible. The orbital ring is
yellow-orange or orange-red. The legs are flesh-pink.