Very pale-eyed adult Caspian Gull from Denmark

[RSNaarhus]

Hi

I saw this apparant adult Caspian Gull at Hirtshals in the northern part of Jutland, Denmark on the 17th of October.

The bird deviates from what I normally associate with Caspian Gulls e.g. with regards to the colour of the iris, rather bulky bill, relatively dark mantle and by the rather large amount of black in the primaries resembling michahellis a little bit.

Is this bird within the variation of european Caspian Gulls?
Could it perhaps have some genetic influence from michahellis?
Or does it better fit more easternly poulations of Caspian Gulls and allies ?

A video of the bird can be seen here: http://www.youtube.com/watch?v=Y6prw5o- ... RcKFV9SCPw

Comments on the ID are very welcome.

Best wishes, Rune Sø Neergaard

[marsmuusse]

Hi Rune,
I think there is too much wrong for pure cachinnans, especially this much black in the wingtip is not okay. there is too much black on the innerwebs of the outer primaries and the upperpart grey tone is wrong. Added the other odd features, I think you found abird from the "Greg Oblast"!

Mars

[RSNaarhus]

Hi Mars

Can you please elaborate on what you mean by a bird from "Greg Oblast" ?

Best wishes, Rune

[Cristian Mihai]

Hybrid Herring x Caspian from East Germany and Poland (area where there are mixed colonies).

[marsmuusse]

Hi Rune,
Not quite the mixed colony I had in mind, the suggestion by Cristian, but as good a guess. I just don't know what to think of the bird:
- it is darker grey on upperparts where it is next to argentatus, which would be odd for tatus x cach hybrid, it looks more like micha in this respect.
- it has black even on the outerweb of p4, which is not typical for cach x tatus probably, but also better for micha.
- it has much black on outer primaries where black runs up high along the edge of the outerwebs, almost reaching the primary coverts, yet on P7-P8 the tongues on the innerwebs seem to run down quite a bit, which is not typical for micha.

Hybrids is the hocus pocus solution to many discussion birds of course, so I tried to think of birds from Greg: http://www.flickr.com/photos/neubauerg/ ... 508214870/

But sorry, it just looks an odd bird to my eyes.

[lou bertalan]

hi rune,

taking single features, there is none that excludes a michahellis here. even the long dorsal tongues on mentioned by mars can be found in black sea YLGs. head is large, eyes pale, much black in wing. still i share mars' feelings that this is not a southern breeder but a (late moulting) northeastern bird, possibly from well inland russia. but we don't know it and won't.
even though some caspian gulls have short tongues (dorsal and ventral), even though some have a lot of black (as opposite to mars i'd say that a small dot of black on p4 is found in more than 50% of all adult type caspian gulls and some have more extended black on p5-p8 also, making them look similar to michahellis), even that quite some YLGs can have pale bill bases in autumn, this bird does not ring strong YLG bells. to me a similarly mysterious possible russian (or white-russian or polish) hybrid.

best,

lou

[RSNaarhus]

Thanks for the comments.

To me the streaking of the hindneck and the thin legs (best seen on video) excludes a pure michahellis.

The bird gave a cachinnans impression in the field, and and I really can´t explain or find relevant links to this but my immedeate thoughts ran to a something "caspianish" somewhere more easternly than the "normal" caspian gulls we see in Denmark.

If anyone can find links to these colonies further inland i Russia it would be appreciated.

Best wishes, Rune

[lou bertalan]

hi rune,

these are some of the pics greg made east of moscow: http://www.flickr.com/photos/neubauerg/ ... 987322384/

best,

lou