Supernavigators

Pigeons, puppies, turtles and bears, all seem to know where they’re going. Why do we get lost so easily? Guest: David Barrie, author of "Supernavigators: Exploring the Wonders of How Animals Find Their Way" and "Sextant: A Voyage Guided by the Stars and the Men who Mapped the World’s Oceans" (rebroadcast)