www.gull-research.org

I found it, when I now viewed my old diapositives.
Photo was taken 1996 near Rostock/Germany. may be important .
Is it a cach or a dark-eyed adult arg?
http://www.abload.de/image.php?img=img0048vv34.jpg

Obvious question: where was it ringed?

In SW-Finland as chick !!!

For me looks like a cach.
Any other opinions?

What about the age of the bird?

Hatched 91 - observed 96.
It is fully adult - ringed as Herring Gull, naturally.

Birds like the one by Ronald here are extremely difficult to identify with certainlty (if ringindg data with known parents are lacking), that is to say birds with mixed characters. Some cachinnans features are quite evident on the subject gull for all to see, but is it a pure cachinnans? My first imression was of a possible mixbird - argentatus x cachinnans (possible a 4cy type with a possible + age), due to structure with a large head and thick neck. I have no emediate problem with the bill shape and size of it, nor the pattern for such an adged cachinnans. My problem would be not seeing the open wing!

Jan

Sorry, I have only this one photo, The problem is, this bird was hatched before cachinnans was known. First for Finland? May be a hybrid, but I am sure it is cach-blooded. I saw many hundreds Finnish ring-bearers on German rubbish-dumps.
Answer for yourself - how would you identify it without any ringing information?

Interesting with dark primary covert marking and pale brownish outer greater coverts in such an old bird, normally clearly non adult characters.
Inside the dark orbital ring a rather pale iris is visible (400%). When is the bird taken Ronald, seems to have rather fresh primarytips. If I put something over the dark looking eye (dark eyes on some Herring Gulls sometimes trigger the unwary birder in the cachinnans direction, not meaning you Ronald ) - there seems to be no reason why it could not be an argentatus, or perhaps better, a hybrid. Even if some (males) cachinnans doe's not meet the standard textbook cachinnans - this gull shows less cachinnans structurally features imo. I would say - unidentifyable. However, given a view of the open wing...maybe

http://gneubauer.republika.pl/More_adult_gulls.html

http://gneubauer.republika.pl/Apr2009.html

Jan

Photo was taken in March 1996 near Rostock (Baltic Germany). Ringed as chick 1991 Kirkkonummi/SW-Finland.

I see a dark-eyed argentatus, not that uncommon in subad argentatus from there, remember Ronald??
We saw quite a few there in August on Tampere.

Theo