From steamy jungles to dry deserts, amphibians have taken their first footsteps onto land using their bizarre life histories to break their ties with the water and invade the earth.
This episode delves into the extraordinary and intimate lives of the soft skinned amphibians. This includes the marsupial frogs, a peculiar species where the father carries his young in pouches and then gives birth. It also features warring giant salamanders over a metre long and show-off newts that offer displays just like underwater birds of paradise.

David Attenborough reveals the fascinating lives of snakes, the most misunderstood group of reptiles. A CCTV stakeout of wild rattlesnakes hunting shows, for the first time, what sophisticated predators they truly are. Attenborough is also on the receiving end of a spitting cobra's chemical weapons system, while the surprisingly beautiful and tender side of snakes is displayed in the sinuous courtship of kingsnakes, and the water birth of 15 beautiful yellow anaconda babies.

Planet Earth is quite simply the greatest nature/wildlife series ever produced. The ultimate portrait of our planet looks at the key factors that shape our natural history. The sun and fresh water dominate the lives of all animals and plants on Earth and trigger seasonal migrations, small and large.

Fresh water is our most precious resource and it defines the distribution of life on land. Follow the descent of rivers from their mountain sources to the sea. Watch spectacular waterfalls, fly inside the Grand Canyon and explore the wildlife below the ice in the world's deepest lake. Witness unique and dramatic moments of animal behaviour: a showdown between smooth-coated otters and mugger crocodiles; deep-diving long tailed macaques; massive flocks of snow geese on the wing and a piranha frenzy in the perilous waters of the world's largest wetland.

The Cave of Swallows in Mexico is a 400m vertical shaft, deep enough to engulf the Empire State Building. The Lechuguilla cave system in the USA is 193km long and 500m deep with astonishing crystal formations hanging from its chambers. Although often overlooked, caves are remarkable habitats with equally bizarre wildlife. Cave angel fish cling to the walls behind cave waterfalls with microscopic hooks on their flattened fins. Cave swiftlets navigate by echo-location and build nests out of saliva. The Texas cave salamander has neither eyes nor pigment. Unique access to a hidden world of stalactites, stalagmites, snotites and troglodytes brings a wealth of surprises.

Through ancient manuscripts and oral tales Michael Wood charts the first human migrations out of Africa. He travels from the tropical backwaters of South India through lost ancient cities in Pakistan to the vibrant landscapes of the Ganges plain. In Turkmenistan dramatic archaeological discoveries cast new light on India’s past.