Nature's Great Events

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? 
Every summer in the seas of Alaska, humpback whales, sea lions and killer whales depend on an explosion of plant life, the plankton bloom; it transforms these seas into the richest on Earth, but these animals may not survive to enjoy the great feast.
The summer melt of Arctic ice, opening up nearly 3 million square miles of ocean and land, provides opportunities for millions of animals, including beluga whales, families of Arctic foxes, vast colonies of seabirds, and the fabled Arctic unicorn, the narwhal, but for polar bears it is the toughest time of year. How will they survive? Narrated by David Attenborough.
Category:Documentaries