isn't a juvenile American Cliff Swallow - (Petrochelidon pyrrhonota) ?
Arne Kiis skriver mandag 28. november 2011 kl. 13.09
Massimiliano, your have a valid point.
To my eye the bird above looks like a different species (or age group) than this: http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=44475.
Three local birders present also watching a flock of c. 100 swallows (in which the bird above and the other one was) disagreed 2:1 on whether all were Barn's or not.
In my eyes it looks like a Cave Swallow, ssp. pallida.
The unmarked reddish throat looks good for a Cave Swallow.
I would expect to find some blackish on the throat of an American Cliff Swallow, and I would expect to find a very dirty looking dark throat if it was a juvenile.
It is clearly not a Barn Swallow. Even the juvenile of that species has a much deeper fork in the tail, and the undertail coverts would not be spotted as in the swallow above. Furthermore it would have a blackish mark on each side of the breast (a collar broken in the middle).
Palle Jensen skriver mandag 28. november 2011 kl. 20.04
The bird is a Cave swallow juvenile, as Bent says.
Buffy throat, not dark as on Cliff swallow.
This species is often seen together with Barn swallow.
English version
Massimiliano Dettori skriver mandag 28. november 2011 kl. 12.16 
