Rough legged Buzzard (1 Viewer)

Unfortunately no photographs, but this bird grabbed my attention because of the white on the tail. at first thought Harrier as it was in flight and could not see outline, but as it flew over it quite clearly was a Buzzard very light underneath. Any thoughts, bird was seen in East Anglia and I've been advised that this is the time for raptor migration. Any further thoughts?

The crucial thing is how the "white on the tail" was patterned. Pale Common Buzzards often have a pale base to the tail, narrowing towards the tip in a wedgeshape. Pale underside of body is actually more typical of pale buzzards than for RLB, where most individuals (and all juveniles) have a solid dark belly.