Secrets of the Penguins

Over two extraordinary years, National Geographic Explorer Bertie Gregory discovered never-before-filmed secret traditions, surprising intelligence and close-knit societies of penguins. This astonishing series reveals they are more like us than we ever dreamed, from their powerful friendships to the courageous risk-takers using ingenuity and innovation in some of the world's most extreme places.

Cast: Blake Lively, Bertie Gregory