Nature's Great Events is a wildlife documentary series produced by BBC Natural History Unit, Discovery Channel and Wanda Films which looks at how seasonal changes powered by the sun cause shifting weather patterns and ocean currents, which in turn create the conditions for some of the planet's most spectacular wildlife events.
Each episode focuses on the challenges and opportunities these changes present to a few key species.
The series aired in the UK on BBC One from 11 February to 18 March, 2009. There are six hour-long episodes in one season.
Nature's Great Events premiered in South Africa on SABC3 on Sunday 30 December 2012, at 18h00. New episodes broadcast weekly.
Using state-of-the-art filming technology, Nature's Great Events captures the Earth's most dramatic and epic wildlife spectacles and the intimate stories of the animals caught up in them.
From the flooding of the Okavango Delta in Africa, to the great summer melt of ice in the Arctic and the massive annual bloom of plankton in the northern Pacific Ocean, each episode features a different event set in one of the world's most iconic wildernesses.
The characters include tiny grizzly bear cubs emerging from their den in snow-covered mountains, baby elephants struggling to survive against drought and lion attack in Africa, humpback whales hunting as a team, the world's largest concentration of dolphins and sharks gathering off the coast of South Africa, and polar bear families navigating their precarious way on ever-thinning ice.
The world-renowned BBC Natural History Unit uses sophisticated high-definition cameras, and cutting-edge aerial, underwater and ultra-slow-motion filming techniques to capture in intimate detail some of the viewers' best-loved wildlife, as their lives become entwined with these dramatic events.
With emotion, intimacy and powerful storytelling, this series charts the effects of global climatic phenomena which transform entire landscapes, drawing in thousands of animals and determining their fate.
Each episode is set in a different part of the world and shows how immense natural forces, often starting thousands of miles away, drive a chain reaction that culminates in a spectacular wildlife event.
Cameras follow the drama at every level, revealing how these unique places form the epicentre of a massive wildlife spectacle.
As the Earth is rapidly changing, we can no longer take these great natural events for granted. By filming the events and their fluctuations, this series takes the pulse of the planet.
For some animals, these events are a window of opportunity, but for others, they are the most dangerous time of their lives. Follow their emotional, involving stories to a dramatic climax where their fate will be revealed.
Who will be the winners and losers?
Episode 1: The Great Melt
As winter finally passes and the sun climbs over the Arctic, the 4,000,000 square mile ice-sheet rapidly begins to melt, revealing an archipelago of islands, channels and seas.
For the masters of the ice, the polar bears, this is a moment of jeopardy but for others like the arctic fox, beluga whales, thousands of lemmings and immense flocks of birds this brief summer transforms the Arctic into the richest place on Earth.
Episode 2: The Great Salmon Run
The temperate rainforest of British Columbia, Canada, harbours more life than any other forest in the world. Cloaked by the planet's tallest trees, the last big carnivores of North America roam free - the great grizzly bear and forest wolf.
Yet their survival depends entirely on one great event that runs up the rivers just once a year. As the rivers teem with spawning salmon the bears and wolves are drawn together and a deadly conflict unfolds.
Episode 3: The Great Migration
The parched grassland of East Africa's famous Serengeti plain is the arena for bitter rivalries between warring cheetahs, lions and hyenas as they struggle over meagre pickings.
But with the arrival of the annual rains the plains momentarily flush green with fresh grass drawing in the greatest concentration of large animals on the Planet.
Over two million wildebeest, zebra and Thomson's gazelle have undergone an epic journey crossing crocodile infested rivers to graze here - but how will they survive the arena of carnivores?
Episode 4: The Great Tide
As winter arrives along South Africa's east coast the inshore waters cool, drawing billions of sardines northwards from the Cape to feed on the plankton-rich soup.
The Sardine Run is the greatest marine spectacle on the planet, attracting an awe inspiring cast of ocean predators. Mega pods of common dolphins, battalions of sharks and greedy brydes whales feast on the sardines as gannets rain down from above.
For African Penguins and bottlenose dolphins this movement of sardines is the defining moment of their lives. Both are living on a knife edge, and only the run of sardines can save them.
Episode 5: The Great Flood
In the intense heat of the northern Kalahari a herd of elephants trek towards a lifesaving goal while prides of lions and marooned hippos fight to survive around the last remaining waterholes.
Their fortunes change dramatically with the annual flooding of Botswana's Okavango Delta, turning 6,000 square miles of desert into a maze of lagoons, islands and swamps.
As millions of animals are drawn to the oasis, including great herds of near-starving elephants, the scene is set for one of the greatest clashes in nature.
Episode 6: The Great Feast
The arrival of spring sunshine triggers an explosion of life in Alaska's coastal waters so great that it eclipses even the Amazon rainforest.
The feast draws in an amazing cast of characters, including humpback whales and their new-born calves who migrate all the way from Hawaii to spend the summer feeding in these rich waters, and resident sea lions who are also in a race against time to make the most of the good times before the harsh Alaskan winter closes in.
Can the whales and sea lions catch enough fish – and avoid the predatory killer whales – to see them through?