Wildlife experts believe it could take up to 18 months before a barn owl moves into a nest box.

BBC: Barn owl at a farm

If you expect a private money manager to catapult you and your nest egg onto the Forbes 400 Richest People in America list, take a deep breath.

FORBES: Move over, mutual funds

But Mr Fothergill joked he would take the nest down once the crows' young had fledged because he feared looking ridiculous out at sea with a real crow's nest on his mast.

BBC: Crow's nest built on yacht mast in Aberystwyth