Mammals dominate the planet. They do it through having warm blood and by the care they lavish on their young. Weeks of filming in the bitter Antarctic winter reveal how a mother Weddell seal wears her teeth down keeping open a hole in the ice so she can catch fish for her pup. A powered hot air balloon produces stunning images of millions of migrating bats as they converge on fruiting trees in Zambia, and slow-motion cameras reveal how a mother rufous sengi exhausts a chasing lizard. A gyroscopically stabilised camera moves alongside migrating caribou, and a diving team swim among the planet's biggest fight as male humpback whales battle for a female.

At the end of each Antarctic summer, the emperor penguins of the South Pole journey to their traditional breeding grounds in a fascinating mating ritual that is captured in this documentary by intrepid filmmaker Luc Jacquet. The journey across frozen tundra proves to be the simplest part of the ritual, as after the egg is hatched, the female must delicately transfer it to the male and make her way back to the distant sea to nourish herself and bring back food to her newborn chick.

In the fourth episode, leading landscape photographer Peter Eastway follows in the footsteps of Frank Hurley – the pioneering Australian photographer on Shackleton’s expedition to the south a century ago – to capture the wilderness and wildlife of Antarctica and South Georgia.

Experience the world from the viewpoint of animals themselves. From spellbinding wildlife spectacle to intimate encounters, Planet Earth II takes you closer than ever before.
Remote islands offer sanctuary for some of the planet's strangest and rarest creatures. The rare pygmy three-toed sloth enjoys a peaceful existence on an idyllic Caribbean island, while nesting albatross thrive in predator-free isolation. But island life always comes at a cost. On the Galapagos Islands, young marine iguana must escape an onslaught of deadly racer snakes the moment they hatch from the sand. On the sub-Antarctic island of Zavodovski, life gets more extreme still. Every day, one and a half million penguins risk being battered against the rocks by fierce waves as they try to get on and off the island.

As almost all animal inhabitants of Antarctica are forced to migrate north, the sea underneath the frozen ice still provides a home to many specially adapted fish whose cells are protected from freezing through an 'antifreeze' liquid. Many of them feed on the faeces of other animals. The most notable larger animal that does not migrate north is perhaps the Weddell Seal, which can be found as close as 1300 kilometres to the pole. Groups of seals tear holes into the ice to dive for food and come up to breathe. The females come back to the ice to give birth. This episode also describes primitive plant life such as lichen, which can still be found on the continent in winter, even in the extremely dry and permanently frozen valleys conditions under which dead animals can lie frozen for many centuries without decomposing. It details the life of the Emperor Penguin, 'the only birds to lay their eggs directly on ice'. While other animals retreat, Emperors migrate not just to the ice, but into the Antarctic continent. The females lay eggs which are incubated by the males under the harshest conditions on Earth (huddling closely together for warmth), while the females return to the sea.

This episode is centered around how science, in particular the work of Clair Patterson (voiced in animated sequences by Richard Gere[33]) in the middle of the 20th century, has been able to determine the age of the Earth. Tyson first describes how the Earth was formed from the coalescence of matter some millions of years after the formation of the Sun, and while scientists can examine the formations in rock stratum to date some geological events, these can only trace back millions of years. Instead, scientists have used the debris from meteor impacts, such as the Meteor Crater in Arizona, knowing that the material from such meteors coming from the asteroid belt would have been made at the same time as the Earth. Patterson also examined the levels of lead in the common environment and in deeper parts of the oceans and Antarctic ice, showing that lead had only been brought to the surface in recent times. He would discover that the higher levels of lead were from the use of tetraethyllead in leaded gasoline resulting in government-mandated restrictions on the use of lead.