As seen on PBS's American Spring Live, one of America's great nature-writers explores the magic and science of feathers Feathers are an evolutionary marvel: aerodynamic, insulating, beguiling. They date back more than 100 million years. Yet their story has never been fully told. In Feathers, biologist Thor Hanson details a sweeping natural history, as feathers have been used to fly, protect, attract, and adorn through time and...