Jeroen: In theory all this Natrix are helvetica (!!), but I've some indication and two paper under press that make me think that we can have or we have some astreptophora enter in SW Pyrénées... The blue one is a good example !
Yes, I think too that the Coronella will shed. I can't imagine the same after sheding !
Very nice photos. I´m impressed with a blue Natrix in Pyrinees! When I talked about north Spain Natrix natrix I always thought in Burgos, Cantabria, Galicia, etc... where I have usually seen "ugly" colorated snakes (brown, grey, green). I didn´t know that in northeastern Spain is also possible to find the blue individuals typical of central and south Spain. Wow!