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.

The documentary deals with the future of conservation. It begins by looking at previous efforts. The 'Save The Whales' campaign, which started in the 1960s, is seen to have had a limited effect, as whaling continues and fish stocks also decline. In the 1990s, as head of the Kenya Wildlife Service, Richard Leakey took on the poachers by employing armed units. Although it was successful in saving elephants, the policy was detrimental to the Maasai people, who were forced from their land. The need for "fortress" areas is questioned, and the recently highlighted Raja Ampat coral reef in Indonesia is an example. The more tourism it generates, the greater the potential for damage — and inevitable coastal construction. Sustainable development is viewed as controversial, and one contributor perceives it to currently be a "contradiction in terms". Trophy hunting is also contentious. Those that support it argue that it generates wealth for local economies, while its opponents point to the reducing numbers of species such as the markhor. Ecotourism is shown to be beneficial, as it is in the interests of its providers to protect their environments. However, in some areas, such as the Borneo rainforests, the great diversity of species is being replaced by monocultures. The role of both religion and the media in conservation is argued to be extremely important. Contributors to the programme admit a degree of worry about the future, but also optimism.

The final episode of the series visits the frontline of the conflict with the world's top predators, meeting the scientists fighting to save them. Crossing five continents and combining landmark natural history footage with real-life human drama, it checks the pulse of the earth's iconic animals, including lions, tigers, polar bears and blue whales. With three-quarters of the planet's carnivores now in decline, can people find ways to live with predators before they disappear forever?

Why do we sleep? And what does sleep have to do with memory, trauma, and our emotions? From fruit flies to whales, virtually every animal sleeps. But why? Why do we need to spend nearly a third of our lives in such a defenseless state? Scientists are peering more deeply into the sleeping brain than ever before, discovering just how powerful sleep can be, playing a role in everything from memory retention and emotional regulation to removing waste from our brains. So why are we getting so little of it?

The series takes place after the extinction of the dinosaurs 65 million years ago and recreates animals of the Cenozoic with computer-generated imagery and animatronics. The first episode starts 49 million years ago, when Earth has fully recovered from the dinosaur extinction and is covered in a mysterious forest. This is a time that the world has almost forgotten - Germany was a hot sweaty jungle, birds ruled the earth and preyed on miniature horses and whales walked on land.

In the first episode, Sir David Attenborough reveals the unexpected wildlife riches of the British Isles, showcasing the dramatic and spectacular habitats that rival any across the globe. This journey uncovers the diversity of life in the UK's unique landscapes, from the intricate world of bumblebees to the swift lives of kingfishers. The episode captures extraordinary scenes of nature, including killer whales preying on seals, golden eagles in the Scottish mountains, the cunning tactics of woodland plants, and the perilous life of puffins evading gulls. It highlights Britain's geological diversity as a cornerstone of its natural wealth, contributing to an array of habitats and supporting a wide range of life.
Britain's importance extends to being a haven for migratory birds, with our seas feeding 65% of the world's gannets and supporting the largest colony of northern gannets on Scotland's Bass Rock. The west coast of Scotland offers sanctuary to barnacle geese due to its abundant food and mild climate, though they remain vigilant against hunting sea eagles. Despite these natural treasures, Britain faces challenges as one of the most nature-depleted countries globally. Sir David Attenborough emphasizes the need to conserve and restore these wild isles for the enjoyment and benefit of future generations.