Hi Helen
There are actually 8 recorded 'white' Red Kites in Wales, so T.Cross from Gigrin Farm told me. He's our swan ringer and I chatted to him after I'd read this post. We also rehabilitate all the Red Kites that come to him injured.
Here's a link ti Gigrin if anyone wants to take a look
http://www.gigrin.co.uk/w/
Tragus