Covert moult in argentatus

[JanJ]

Some good images- recently taken in southern Sweden by Mårten Müler - showing advanced covert moult and a single tertial in one individual in (presumably) argentatus. Not a common feature but seen i maybe less than 5 % (?) of argentatus.

The top 5 pic. and some other individuals:

http://www.pbase.com/m_muller/herring_gull

JanJ

[Ruud Altenburg]

Interesting to see that it occurs in both wings, as usually so many new coverts are a result of some sort of accident.

I would hesitate to call this bird a Herring though... http://www.pbase.com/m_muller/image/119169681

[JanJ]

Yes Ruud, i forgot to emphazise 'both sides', which is a matter of importance.
The tree first at the top on the mentioned site, are of the same individual - the two last would be of the same individual. Regarding the one which made you hesitate, do you consider perhaps an argentatus x cachinnans, or something else? I might miss something here ( ) but take away the covert moult and there would be no problem calling it an argentatus. BTW rather similar in billshape, structure and pattern to this one (although taken end of Jan.

http://www.pbase.com/slisch/image/108806621

Interested in hearing your thoughts Ruud.

JanJ

[Ruud Altenburg]

Well it's not unlike some of those W Mediterranean michahellis. However, given the rather short wings and notorious similarity of some Baltic Herrings to YLG I opted for a careful phrasing

[JanJ]

Of course Ruud, especially nr 6 regarding plumage features.

[marsmuusse]

Today, Scheveningen - Holland. 1cy teus (?).

[marsmuusse]

Today, Scheveningen - Holland. 2cy argenteus (?).

[Lars krogh]

2cy first vinters argentatus 13.01.10 Rødvig havn , Denmark

[Theo Muusse]

Wow, attractive Herrings!

Theo

[marsmuusse]

Probably the most difficult location to be certain when you find 2nd gen like wing-coverts, as the central greater coverts are the last feathers in the wing-covert panel to grow in. Therefore, being the last in the sequence, they may sometimes look slightly more 2nd gen like.
However, the feathers in this bird are both very neat and fresh, and also different in pattern (but note the adjacent feathers further outwards).

Difficult........