I really do hope you meant white tailed sea eagles. Which is what they are ... Just check the nearest bird book of Europe, North Africa and the Middle East.
Other than that: great shot of a magnificent bird!!!
Incidentally: are they destined to be part of a reintroduction effort in Wales?
If they are they must be very young birds - adults that I've seen have a much yellower beak and (of course) white tails!
In addition, this looks a lot like the Golden Eagle aviary (built specially for the species), unless they have moved them around recently - it's been a while since I was last there so I could be out of date on this point.
If these are young sea eagles then fair enough - but I would never have got that from this photo!
ISIS lists up 2.0 sea eagles, 0.1 golden eagle and 1.1 Verreaux's eagle.
To my mind they really do look like juvenile sea eagles. I have seen these magnificent birds both in the flesh in several raptor zoos as well as in the wild (they frequent the Netherlands coastline in wintertime and a pair has been nesting in the central wetlands for the last few years (rearing chicks and all).
