3cy Cachinnans x Argentatus ?

[RSNaarhus]

Hi

I would like some comments on this bird photographed at Nørre Vorupør in the northwestern part of Jutland, Denmark on the 20th of January.

IMO it looks very different from the normal 3cy Herring Gulls, I see in Denmark. The white head and underparts, long legs and bill reminds me of cachinnans but mantle-colour, tailpattern, barring to the upper tailcoverts, missing white window in p10 and pattern of the wingcoverts does not seem to fit Caspian Gull very well.

Do you think this bird is within the variation of Herring Gull?

Best wishes, Rune Sø Neergaard, Denmark

[marsmuusse]

Hi Rune,
Although one may argue most of the features on thgis bird also fit on argentatus, there are firm clues that at least one of the parents must have been cachinnans. It would not surprise me if it also fits in the variation found in true cachinnans.

[lou bertalan]

Hi Rune,
Although one may argue most of the features on thgis bird also fit on argentatus, there are firm clues that at least one of the parents must have been cachinnans. It would not surprise me if it also fits in the variation found in true cachinnans.

each feature, taken alone would indeed fit in the variation of cachinnans but there is too much of it...probable hybrid for me.

[JanJ]

I agree that Rune´s pic doesn´t absolutely excludes an argentatus. On the other hand - diffucult as it may be to come to a positive identity, I would hesitate to call it a pure cachinnans. There´s something about it´s structure with a large head and a short bill that cast some doubts on it being pure cachinnans.

http://www.helsinki.fi/~rauste/gulls/hannu61.html
http://www.helsinki.fi/~rauste/gulls/hannu10.html

However, some mix arg x cach may do the trick...

Some new pic of Hannu here:

http://hjkoskinen.kuvat.fi/#/kuvat/Lithuanian+Gulls/

JanJ