From the Arctic to the southern United States stretches the largest forest in the world. David Attenborough roams from north to south through this spectacular woodland, starting amid conifers high in the Arctic Circle and ending among the giant sequoia trees of the Sierra Nevada. Among the wildlife he encounters are huge great grey owls, sapsucker woodpeckers, hummingbirds, raccoons, chipmunks and burrowing tortoises.

David Attenborough explores the grasslands of the Americas, Eurasia and Africa, and encounters the rare maned wolf, a giant anteater, bison, prairie chickens, Russian antelopes and more. In the Sudan hewitnesses the Merle tribe hunting amongst the spectacular migration of a million white-eared kob antelope.