Dark underwings

[adriaens]

A nice example of a 1st-cycle Caspian Gull with brown underwing, from Belgium 18/12/2010:
http://picasaweb.google.com/Zorkyyy/Cas ... 0890405554
http://picasaweb.google.com/Zorkyyy/Cas ... 2935538786
http://picasaweb.google.com/Zorkyyy/Cas ... 7373767810

Perhaps it is a good idea to collect photos of such birds in this topic. Anyone got any more ?

[WolfgangSchweighofer]

Good morning,

yesterday I had this one at Gneixendorf/Austria. I think there is more material, later, if I have more time.

Wolfgang

[JanJ]

Hello Peter.

Everything from the pale classic - http://www.pbase.com/slisch/image/127132070 - to Herring dark - http://www.pbase.com/slisch/image/126518769 (note the date, July) - is apparently to be considered. Some say that the axillaries can be barred heavily but only at the very tip of each feather and so on - http://www.pbase.com/slisch/image/128372061

If these are all pure Caspian, the range of variation is surely something to consider:

http://www.elisanet.fi/antero.lindholm/ ... siipi.html

What do you make of this one then?

http://www.tarsiger.com/gallery/index.p ... 6&lang=eng

More examples here:

http://www.tarsiger.com/gallery/index.p ... DESC&sel=2

JanJ

[adriaens]

What do you make of this one then?

http://www.tarsiger.com/gallery/index.p ... 6&lang=eng

That is the kind of gull that fries my brain circuits... The longer I stare at the photos, the more my mind goes blank and my body goes into foetal position
The extremely simple pattern of scapulars and wing coverts (recalling juv. Audouin's Gull) looks great for Caspian Gull, but that underwing is just so brown!
I suppose Finland may not be the best place to study variation in Caspian Gull, as the species is still rare in that country. Better to start with the core breeding and winter ranges.

[lou bertalan]

What do you make of this one then?

http://www.tarsiger.com/gallery/index.p ... 6&lang=eng

That is the kind of gull that fries my brain circuits... The longer I stare at the photos, the more my mind goes blank and my body goes into foetal position
The extremely simple pattern of scapulars and wing coverts (recalling juv. Audouin's Gull) looks great for Caspian Gull, but that underwing is just so brown!
I suppose Finland may not be the best place to study variation in Caspian Gull, as the species is still rare in that country. Better to start with the core breeding and winter ranges.

a lot space for speculation here and the tarsiger juv may indeed be from one of those horror places with interbreeding heuglini/cachinnans or cahinnans alikes somewhere in russia. but if there are crisp patterned dark caspians (like peter's and wolfgang's recent and many of my sept. birds), why shouldn't there be a dark soft patterned bird among them? fact is, that many capians indeed look dark on underwing and i guess this doesn't have to do with genes of other species.

[WolfgangSchweighofer]

Hi,

just at home and more time now. Otherwise - there would be perfect conditions now to observe gulls at Krems/Donau like I have done yesterday. Today blue sky, 0°C and ice, perfect to read rings...

Maybe birds in juvenile plumage are darker? I think that such "dark" birds like this one I have shown above are quite "normal". Don´t forget photgraphical effects. Here are some further püic´s from yesterday, maybe all from the same bird. The Auistrian flock now consists of approximately 80% cachinnans, 15% HG and 5 % YLG.

[Theo Muusse]

What do you make of this one then?

http://www.tarsiger.com/gallery/index.p ... 6&lang=eng

That is the kind of gull that fries my brain circuits... The longer I stare at the photos, the more my mind goes blank and my body goes into foetal position
The extremely simple pattern of scapulars and wing coverts (recalling juv. Audouin's Gull) looks great for Caspian Gull, but that underwing is just so brown!
I suppose Finland may not be the best place to study variation in Caspian Gull, as the species is still rare in that country. Better to start with the core breeding and winter ranges.

To me, with fried brains, it has a certain lbbg in it.
For me that explains something...

Theo

[JanJ]

Quite true Theo....


JanJ