E1 - The Great Melt

Aired: February 11, 2009

The summer melt of Arctic ice provides opportunities for millions of animals.

E2 - The Great Salmon Run

Aired: February 18, 2009

Every year, the survival of grizzly bears in North America depends on a spectacular natural event: the return of hundreds of millions of salmon from the Pacific Ocean to the mountain streams where they were born. This great return provides food not only for bears, but for killer whales, wolves, bald eagles and the very forest itself. Will the salmon return in time to keep the hungry bears alive?

E3 - The Great Migration

Aired: February 25, 2009

The story of a lion family's struggle to survive until the return of the great migration.

E4 - The Great Tide

Aired: March 04, 2009

A look at the sardine run, which happens each winter along the South African coast.

E5 - The Great Flood

Aired: March 11, 2009

Millions of animals time their migration across the Kalahari Desert to coincide with the the annual flooding of Botswana's Okavango Delta.

E6 - The Great Feast

Aired: March 18, 2009

The summer plankton bloom in the north-east Pacific draws in animals in great numbers, from the billion-strong shoals of herring to migratory humpback whales.