In this bird's-eye view of two continents, demoiselle cranes negotiate a dangerous Himalayan pass on their way to India while high-flying bar-headed geese take the fast track five miles above. In Rajasthan, vultures watch hunting tigers hoping for a meal and pigeons visit a temple dedicated solely to sacred rats. Pigeons are also our guide to the greatest gatherings of camels on Earth and learn to dodge buzzards around the battlements of Jodhpur Fort. 9,000 cranes overwinter in the most unlikely of spots - a barbed wire compound in the centre of a desert town. In Australia, rainbow lorikeets drop in on Sydney and patrol Australia's Gold Coast. In the outback, white cockatoos swirl in thousands and budgerigars pass Uluru (Ayers Rock) and gather in the biggest flocks ever recorded. In China, swallows and swifts visit the Great Wall and the Forbidden City of Beijing. In Japan, the country's most revered birds - Japanese cranes are fed fish by appreciative locals and are joined in strange, momentary harmony by hungry red foxes, white-tailed eagles and Steller's eagles. As peace descends, Japanese cranes dance beautifully in the snow.

David Attenborough comes face-to-face with a baby rhino and asks what the future holds for this little one. He meets the local people who are standing side-by-side with the wildlife at this pivotal moment in their history. We discover what it takes to save a species, hold back a desert and even resurrect an entire wilderness - revealing what the world was like before modern man.

As the journey continues, there's beauty and danger in equal measure for Charley Boorman and Ewan McGrego. The duo ride their electric Harleys through the exotic and breathtaking Bolivian countryside in a tough ascent. The sixth episode showcases some of the challenges the hosts and the crew face when they scale the terrain. One of the Rivians runs into trouble while sandy roads and a heavy breeze sees Boorman take a tumble. Apart from all the accidents, the chapter also shows some quality work done by UNICEF when it comes to educating and working with the children in Bolivia.
The altitude sickness hits Taylor, their logistics man real bad and McGregor starts feeling it as well. The episode ends with a doctor heading to his hotel room to check up on him.

From the frozen poles to the searing deserts, this episode shows how animals have come up with strategies to survive the uneven amounts of sunlight that fall on our planet over the course of a year. The exception is on the equator, where the duration of day and night remain the same throughout the year. Here, this guaranteed sunlight drives the great diversity of life in the tropical jungles.

Weather controls the distribution of freshwater on Earth. David Attenborough narrates how this uneven distribution has given rise to an incredible diversity of species and habits, from the driest desert to the lushest tropical rainforest. Featuring a colony of ants banding together into a raft every time its home in the Amazon floods, a rain frog that manages to eke out an existence in one of the world's driest habitats on Earth, and the last wild camels that survive the Gobi Desert's bitter winters by eating snow that blows in from Siberia.

In the spectacular deserts of coastal Peru, archaeologist Dr Jago Cooper explores the dramatic rise and fall of Chimor, the first empire of South America. His journey begins among the ruins of a vast lost city once home to an all-powerful monarchy, whose subjects transformed the desert landscape, created gold and silver treasures and believed so strongly in the power of their gods that they made the most shocking of sacrifices. Chimor thrived despite facing some of the most extreme climate conditions in the world, but not even this powerful empire could withstand the forces that eventually destroyed it.