All these images were taken at Sant Carles de la Rapita, on the Ebro Delta, Catalunya, Spain. I waited for the fishing boats to come back from their day at sea - always a nice opportunity to take photos. The first set is of Audouin's Gulls.
Adult Yellow-legged Gull
Another adult Yellow-legged above; below is a selection of 2 cy Yellow-legged Gulls
Note that due to moult of some 1 gen feathers and replacement with white ones, the underwing looks rather pale on this bird.
I was looking through some old images yesterday and came across this bird from Spain (Ebro Delta, Catalonia) from 2006. The image above shows a very unusual pattern for YLG - no black on P5 combined with a wholly white tip to P10. It also has rather limited black on P6. So overall it appears to have lots of white and little black in the wing tip. However, as can be seen in the image below, it has a more normal pattern on P5 and 6 on the left wing. Of course asymmetrical primary patterns are not so unusual in large gulls, but the asymmetry tends to be subtle - this bird is rather extreme, with no black at all on P5 on one wing and a normal amount on the other. 
Audouin's Gull - always beauties. 
Black Kites had arrived in good numbers - this is one from Lleida rubbish dump 
Night Heron 
Great-spotted Cuckoo - early spring is great for these birds, as they are very vocal. 
Yellow-legged Gull. A bird sporting a fully white tip to p10 
Yellow-legged Gull. 
Yellow-legged Gull. This has an unusual p10 pattern, combining a rather long grey tongue (approx half the length of the exposed feather) and a fully white tip. 
A rather more typical bird. 
I spent a great couple of days in Tarragona, with Albert Cama and Joan Ferrer Obiol. Amazingly, we managed to find 3 Caspian Gulls in the harbour- two 1w birds and a 2w. These are little more than records shots, but worth posting as this species remains unusual in NE Spain. Above is one of the 1w birds, captured in a flock of Yellow-legged and Lesser Black-backed Gulls 
The same 1w bird, with a LBB
A different 1w bird (left), showing off its jizz to full effect. 
The 2w bird - subtle yet distinctive. The p10 mirror is visible on the underside of the far wing. 
Derek - hope these help our discussion....
This one looks slightly odd, but i think it is simply because I've caught it here in an alarmed, nervous pose.
I had this bird with an extreme amount of white in the primaries (note especially P8) at the weekend. Great looking bird, but unfortunately I cant make it into anything but a canus.
The same bird as above. Just a rather typical 2w herring, except for the tail. 
The same bird as above.
Gull watchers in USA are on the hunt for Vega. Key to this, especially on the east coast, is separation from European Herring. Various subtle ID features have been mooted for Vega in first winter plumage, but before this we need to fully appreciate the variability in Herring Gulls. This small contribution illustrates differences in overall colour and especially the tail and rump patterns of Herring. The bird above is rather white tailed, with a narrow dark terminal band and and 2-3 clear bands more basally (formed by dark crescents) - overall, a pattern rather like a Rough-legged Buzzard.
A rather everage tail and rump pattern, with the dark terminal 'band' more than half of the total tail area and white restricted to basal triangles
Slightly more than average black in tail, and a well barred rump and upper tail coverts
A milky-coffee bird.
The same milky bird. 
