Common crane ? is it possible ?

[hotpepper]

I was in North Buckinghamshire in open farming country with a number of ponds and saw a large bird flying away from me - I assumed a heron but as it turned it looked larger than a heron and then did what I have never seen a heron do - it circled riding the thermals until it was so high I lost sight of it. The shape from underneath looked a bit like a heron but the wings looked longer - I though I could see legs out behind.

So could it be a Common Crane ? are they around in UK?

HP

[captaincarot]

they breed in norfolk

[RoyW]

Herons do quite frequently circle on thermals (and tend to look a bit strange when they do this), size can also be difficult to judge and birds often appear larger than they are.
How was this bird holding its neck? Herons almost always have their neck folded into the body in flight, cranes (and storks) keep their necks extended.
Cranes are still very scarce birds away from the small breeding population - it is possible, but a Grey Heron is far more likely so you have to be sure that it wasn't a heron!