The story

A polar bear falls through thin Arctic ice while searching for food for his family. A humpback whale guides her calf on a perilous 4,000-mile journey. A herd of African elephants in search of water battles a sandstorm in the Kalahari Desert.

These dramatic scenes await viewers in "Earth," a feature-length documentary hitting theaters Wednesday for Earth Day.

For British filmmakers Alastair Fothergill and Mark Linfield, surveying the whole planet for Earth's most exotic species and magnificent landscapes was a daunting task.

"We wanted to tell an epic story about the whole planet," co-director Fothergill told CNN in an interview. "We spent a record 2,000 days in the field. We filmed in 46 countries worldwide, on every continent."

Fothergill and Linfield shot the footage for the film while making "Planet Earth," the Emmy-award-winning nature series that aired on the BBC and the Discovery Channel in 2007. See photos from "Planet Earth" Read full article »

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