The Great Salmon Run • episode "2/6" • Nature's Great Events

58:19

Going down into these narrow flooded passageways is not for the faint-hearted but, with only an estimated one percent of the caves explored, it is an opportunity for the team to write themselves into cave diving history, by pushing further in than anyone has before. This is a challenge that tests even the most accomplished cave divers. Steve must face the terrors of being lost in an underwater silt cloud in a cave. But there is a bigger issue at stake. All life in the Yucatan depends on the fresh water in this network of caves, but it's being contaminated by human development. With every metre the team maps, it adds to the knowledge of the system, which, in turns, helps protect it for future generations.

Undiscovered Worlds with Steve Backshall • 2019 • Nature

59:22

The great flood in the Okavango turns 4,000 square miles of arid plains into a wetland.

5/6 • Nature's Great Events • Nature

46:59

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.

2/11 • Planet Earth • 2006 • Nature

5:29

The next time you look in a mirror, think about this: In many ways you're more microbe than human. There are 10 times more cells from microorganisms like bacteria and fungi in and on our bodies than there are human cells.

Nature

58:30

In nature, living long enough to breed is a monumental struggle. Many animals and plants go to extremes to give themselves a chance. Uniquely, three brother cheetahs band together to bring down a huge ostrich. Aerial photography reveals how bottle-nosed dolphins trap fish in a ring of mud, and time-lapse cameras show how the Venus flytrap ensnares insect victims. The strawberry frog carries a tadpole high into a tree and drops it in a water-filled bromeliad. The frog must climb back from the ground every day to feed it. Fledgling chinstrap penguins undertake a heroic and tragic journey through the broken ice to get out to sea. Many can barely swim and the formidable leopard seal lies in wait.

1/10 • Life • 2009 • Nature

20:57

A look at how spiders covered a town in webs overnight and why a lake in South America is the lightning capital of the world.

S1E10 • Nature's Strangest Mysteries: Solved • 2019 • Nature