This fantastic series from the BBC's renowned Natural History Unit combines the epic scale of 'Planet Earth' with the intimate, emotional stories of charismatic animals as they struggle to survive. Using state of the art HD technology, these amazing programmes capture the Earth's most dramatic and epic wildlife spectacles and the intimate stories of the animals caught up in them. Every year, around the world, seasonal changes transform entire landscapes and draw in millions of creatures. For some animals, this is a time of great opportunity but for others it's the most dangerous time of their lives. With stunning photography, this series follows the dramatic stories of key animal characters as these great events unfold. - The Arctic's Great Melt that finds polar bear families navigating their precarious way on ever-thinning ice. - British Columbia's Great Salmon Run where grizzly bears use ingenuity and fancy footwork to collect their catch. - The Great Migration of the Serengeti that tests the survival skills of a pride of lions with young cubs. - The Great Tide of billions of sardines along South Africa's east coast creates an action- packed feeding frenzy of thousands of dolphins, sharks, whales, seals and gannets. - The Great Flood of the Okavango Delta in Botswana draws in families of elephants, who undertake an epic trek to reach it. - The plankton bloom of the Great Feast in Alaska's coastal waters attracts humpback whales and sea lions, who face the dangers of killer whales.