www.gull-research.org

For those who have not yet seen it, and who are interested in such things:

I have created a topic about variation in known-age Herring Gulls on the Surfbirds forum.

The problem with 3cy and 4cy birds is exaggerated by the fact that these ages seem to be the less read so the rarest age to find.
Normally, the combination of gc, sec, tail and inner primaries age the bird, I feel.

But I do remember that in Finland the aging of tatus was tricky as well, even in the hand!

Theo

I have updated the Surfbirds topic with an exceptionally retarded looking 4th-cycle argenteus:
http://www.surfbirds.com/forum/showpost ... ostcount=9

Another update; this time, an American Herring Gull that defies correct ageing...
http://www.surfbirds.com/forum/showthre ... #post36400