Rather pleasantly surprised to have seen a male Montagu’s Harrier, Circus pygargus recently on a day away from my desk. The bird’s altitude and the atmospheric conditions (heat haze) precluded clearer photos. It circled above me, climbing as it did so.
This is a +ID, confirmed by 2-3 other birders on Facebook from the snaps.
According to the RSPB website: The Monty is an extremely rare breeding bird in the British Isles. It is a Schedule 1 listed species and each pair has to be specially protected because its survival is precarious. A summer visitor (wintering in Africa), it seems that whereas like other Harriers, such as the Marsh Harrier it would favour marshes, over arable farmland is a more likely place to see them.