Most British birds of prey have largely recovered from historical persecution, but the beleaguered Hen Harrier is still struggling and remains far less common than it should be. This is a particular shame, because it is one of our most inspiring raptors. Spectacular sky-dancing displays and balletic food passes from male to female brighten up the moors in summer. And in winter, communal roosts in the lowlands attract birders from far and wide to...