In Taiji, Japan, local fishermen hide a gruesome secret: the capture and slaughter of dolphins. Activist Ric O'Barry, who trained dolphins for the "Flipper" TV series, joins forces with filmmaker Louis Psihoyos and the Ocean Preservation Society to expose the brutal practice, risking life and limb in the process.
As the Ganges nears the sea, it joins its mightiest tributary the Brahmaputra, creating a vast flood-prone delta. Here the bustling cities of Calcutta and Dhaka meet the wetlands, home to giant lizards and snakes, huge mean-eating crocodiles and forests full of monkeys. This is a story of human life persisting in wildly variable conditions in a domain that is still the preserve of the royal Bengal tiger.
Welcome to an extreme landscape of rock, ice and snow. We tour the mightiest mountain ranges, starting with the birth of a mountain at one of the lowest places on Earth and ending at the summit of Everest. Find out how some of the most secretive animals rise to the challenge of mountain life. Share one of Earth's rarest phenomena, a lava lake that has been erupting for over 100 years. The same forces built the Simian Mountains where we find troops of gelada baboons nearly a thousand strong. In the Rockies, grizzlies build winter dens inside avalanche-prone slopes and climb the peaks to devour abundant summer moths. In another world first, the programme brings us astounding images of a snow leopard hunting on the Pakistan peaks.
Can animals count? This is a question that has intrigued and fooled investigators for a long time. Just over 100 years ago, a German horse called Hans was declared a mathematical genius but all was not as it seemed. And strangely, some bamboos around the world flower exactly at the same no matter where they are. Are they counting down the years?