The source of the Mekong River is high up in the Tibetan plateau, from there it flows into Yunnan Province, China, where our journey begins. Even though Yunnan occupies less than 4% of China's land, it is home to over half of its birds and mammals. This is due to Yunnan's unique position between temperate East Asia and the tropical south. The Mekong River flows from high altitude alpine forests down to low tropical regions dropping an astonishing 4500 metres in elevation as it carves its 1800 kilometre route through China into Laos. It's this variation in habitats that gives rise to Yunnan's dazzling array of wildlife. From the rare Snub Nosed Monkey - the world's highest living primate (apart from humans) to a record breaking bird that actually scales the Himalayas during its migration: The Bar Headed Goose. Both of these creatures have had to adapt to life at high altitude - the Snub Nose with their distinctive nose to ward off frostbite and a peculiar diet of Lichen - an organism that is found growing on the trees of the alpine forests they call home. The Bar Headed Goose would not be able to complete its death defying migration unless it had a special type of blood and wings packed with capillaries - acting as radiators and warming up as they flap. Moving down from the peaks to the mountain slopes, we meet the enigmatic Red Panda. A lonely creature who searches for a mate in his ever-decreasing territory. Meeting just once a year to they track each other through a method of chemical communication. But with their habitats becoming narrower and more spread out, the chances of them tracking down a potential partner are becoming slimmer and slimmer. As the Mekong drops to its lowest altitude in China, lush tropical rainforests appear that look starkly different to the snow-capped mountains. Here a wealth of exotic flowers bloom as the monsoon rains come in from the Indian Ocean. Deep within this tropical canopy is a battalion of Weaver Ants - fierce creatures who will stop at nothing to get their work done. Building nests takes intricate team work and they even force neighbouring ants to join the cause - actually carrying them to the build site. Mysteries of the Mekong: A Life of Extremes introduces us to this magical river and the level of diversity that can be found in nature. How the creatures here have had to adapt to a life of extremes and the dangers that threaten their survival.