Migrations need generals, admirals and pioneers. These leaders of the pack must keep teeming hordes in line and on track. How well these shepherds stay the course, navigating intercontinental and transoceanic journeys, will determine a species' triumphant survival or deadly collapse.

From the rocky beaches of the Falkland Islands to the dense forests of Costa Rica and from Australia to the desolate savannah of southern Sudan, this episode follows the countless animals that venture forth on timeless journeys, bent on their own survival, and the survival of their species.

From microscopic plankton to rare desert elephants, predatory bald eagles to luminous jellyfish, and ravenous great white sharks to lightning-quick peregrine falcons, our planet is on the move. This episode follows these creatures as they journey looking for food, moving together in numbers and surviving as one.

Migrations are ticking clocks: every day, countless animals must move or die, driven by changing seasons and a changing climate. They are racing to reach their destination, before it's too late to breed, feed or simply stay alive. This episode looks at a range of animals from walruses and whale sharks, and zebras and orang-utans, to pronghorn and plankton.

This film is a unique presentation of the very best footage and spectacular orchestral score of National Geographic's Great Migrations Television Event.