March of the Penguins (2005)
Narrator: [narrating voice over] And they will march just as they have done for centuries, ever since the emperor penguin decided to stay, to live and love in the harshest place on Earth.
Narrator: [from trailer] There is a mysterious ritual that dates back thousands of years. No living creature has survived it except the penguin. They have wings but cannot fly. They're birds that think they're fish. And every year, they embark on a nearly impossible journey to find a mate. For twenty days and twenty nights the emperor penguin will march to a place so extreme it supports no other life. In the harshest place on Earth loves finds a way. This is the incredible true story of a family's journey to bring life into the world: March of the Penguins.