A look at why a humpback whale would hold a diver hostage, how a colony of 1.5 million animals hide from the world in plain sight, and how a surprising stash of acorns could disrupt a whole town.
Every summer, the frozen waters of Hudson Bay partially thaw for a few short months. For migrating beluga whales, it's a seasonal window of feeding and breeding opportunities, but for polar bears, it's a famine-filled test of their survival. Explore the shifting fortunes of a vibrant Arctic world.
In the Land of the Cave Bear, Alice ventures to the parts of the northern hemisphere, hit hardest by the cold - Europe and Siberia. High in the mountains of Transylvania, a cave sealed for thousands of years reveals grisly evidence for a fight to the death between two staving giants, a cave bear and a cave lion. Yet Alice discovers that for woolly rhinos and woolly mammoths, the Ice Age created a bounty. The Mammoth Steppe, a vast tract of land which went half way round the world, provided food all year round, for those that liked the cold. It was these mammoths that Europe's most dangerous predators hunted for their survival.
In the penultimate episode, David Attenborough looks at monkeys. This group started its life in the tree-tops and this is where we join the capuchin, whose acute vision and lively intelligence helps them find clams in the mangrove swamps of Costa Rica and crack them open on tree-anvils. The swamps are also full of biting insects, but the monkeys rub themselves with a special plant that repels them.
Across our planet, there are a handful of places that truly astonish, like Mount Everest, the Grand Canyon and Victoria Falls. These wonders seem to have little in common other than - literally - taking your breath away. But they share one other thing: they pose extraordinary challenges for their inhabitants. The second of two documentaries profiling some of the world's most expansive - and inhospitable - landscapes, and the people who live there. A fisherman in Zambia faces off against crocodiles and risks being swept to his death as he tries to make a living above the imposing Victoria Falls, and in the Amazon, a giant fish offers salvation to a hungry family that calls the river home. A boy's future hangs on the outcome of a single horse race in the vast grasslands of the Steppe, and in a European salt marsh, a young man duels with a savage bull in a centuries-old battle of wills.