another gull - mixed one ? (1 Viewer)

[Michał Jaro]

So what about this one- Poland, Podhale, august.
I can see features of Yellow legged/ Herring/ Caspian , juv. - dark belly (Herring), wing formula (YL/ Caspian), difuse, light wing bars (Caspian), dark primaries and lack of window (YL), striped tail (Herring). Ufffff ...

 

[CARERY]

All primaries dark on inner and out vane, rather weak bill => I'd ID it as juvenile Lesser Black-backed Gull

 

[lou salomon]

All primaries dark on inner and out vane, rather weak bill => I'd ID it as juvenile Lesser Black-backed Gull

You can't see the inner webs in primaries here, Roland. The bird mostly looks like a cachinnans, maybe with argentatus genes, especially due to well marked head.

 

[Michał Jaro]

Many thanks as always!!
I will also ask about features such as a dark belly and a striped tail - should we not pay too much attention to them?

 

[CARERY]

You can't see the inner webs in primaries here, Roland. The bird mostly looks like a cachinnans, maybe with argentatus genes, especially due to well marked head.

I knew I should stay away from gulls X|... Thanx Lou!

 

[Alexander Stöhr]

I knew I should stay away from gulls X|... Thanx Lou!

Thanks for correction from me too, Lou! I was thinking LBBG nearly just in the moment when Roland's comment appeared.

 

[lou salomon]

Had another look on a big screen. It's not a fuscus type anyway (which would show more solid greater coverts etc). One can see parts of the paler inner webs to inner primaries (not completely unvisible like I stated before). But the more or less homogenous dark body/underparts and head together with rather bold markings to uppertail coverts make it very likely a cachinnans x argentatus hybrid (often called 'cactus' among some larophiles).

 

[CARERY]

I didn't consider it to be a fuscus but rather an intermedius. They are moving East after all...

Since you came back to this gull, Lou, I gave it a second look as well. I still find the inner primaries very dark esp. what can be glimpsed of the inner vanes... I always thought that hybrids would in most cases show intermediate features of both parents. So would expect lighter inner primaries, no? A few years back there was a mixed brood of LBBG X Herring Gull. Can you rule out this possibility?

 

[lou salomon]

Not completely from these views, Roland. But bill looks long and very pointed, belly flat (with a bump in front and a bump at rear), both structural features of cachinnans. It looks quite a bulky bird also. And I also find what can be seen from the greater covert pattern pretty cachinnans-like: dark outers with pale tips and filigrane (trapezoid - probably, not really well visible here) bars to inner greater coverts. And yes, primaries are certainly darker than in the average Caspian Gull but still possible. I've seen otherwise perfect cachs with very little pale parts to inner webs; such birds were overall dark types. I find the bold markings on uppertail coverts not very good for an intermedius but, well, argentatus heritage anyway. And yes, quite some intermedius move through eastern Europe and winter somewhere in the eastern mediterranean basin.

 

[CARERY]

Not because I doubt your ID of the OP gull, Lou, but because I think it might be of general interest: I know the person who was documenting a hybrid Herring -x- Lesser Black-backed juvenile of a brood on a roof in Rostock. The two photos are shared with permission...

It shows the only juvenile (not fully grown primaries) opening it's wing, showing the intermediate paler inner primaries I would expect of such a combination. I wonder if a 'Cactus' gull shouldn't show even paler inners? But then, the reason I usually more or less ignore large gulls is their incredible variabiliy of features, which I feel I'd be never ever able to deal with properly