In this special Age of Extinction mini-series from Science Weekly, which first aired in August 2023, the Guardian’s biodiversity reporter, Phoebe Weston, explores the murky world of the illegal killing of birds of prey on grouse moors, and asks why it is so difficult to solve these crimes. In episode two, Phoebe speaks to the people trying to protect these rare birds but, as she digs deeper, she encounters a surprising silence around the killing of a hen harrier’s chicks. Help support our independent journalism at theguardian.com/sciencepod