Explore the breathtaking extremes of our planet in this captivating episode. Journey through the vast Hang Son Doong cave in Vietnam, the largest on Earth. Witness the resilience of life in harsh conditions, marvel at the adaptation strategies of species like the blind cave fish and the enduring Arctic wolf pack. In the Arctic, observe the strategic hunt of wolves preying on musk oxen, a dance as old as the Ice Age. In the French Alps, the struggle for mating among common frogs unfolds, showcasing the urgency and challenges faced by cold-blooded animals. Witness the social dynamics of Barbary macaques in the cedar forests of the Atlas Mountains, where survival hinges on social bonds. The forests of Mexico, home to millions of monarch butterflies that huddle for warmth, illustrates the fragility and beauty of nature.
Discover how fire shapes ecosystems in South Africa's fynbos and Northern Australia, crucial for the survival of species like the golden-shouldered parrot. The documentary poignantly addresses the impact of changing climates and human intervention on wildlife, from the endangered elephants of Amboseli, Kenya, to the secretive snow leopards of the Gobi Desert. This episode offers a profound glimpse into the extraordinary adaptations and challenges faced by wildlife across the globe, reminding us of the delicate balance and beauty of life on Earth.

David Attenborough explores Britain and Ireland’s grasslands, revealing the creatures that create them and the extraordinary stories they hide. From the coastal flower meadows in the Scottish Outer Hebrides to the rich open landscapes in the mountains of southern Ireland, we enter surprising and dramatic worlds.
In southern England, we meet an extraordinary bee that lives in chalk grassland, one of our rarest habitats, laying her eggs in empty snail shells. Meanwhile, in the colourful machair of the Hebrides, ringed plovers and lapwings strive to rear their families of tiny fluffy chicks and to save them for marauding gulls.
We travel back in time to explore the vast wild grasslands once found throughout our isles, before meeting herds of semi-wild horses, where males battle fiercely for the females. Today, they are helping to turn some of this land back to wilderness. And in our precious remaining pockets of flower-rich meadow, a remarkable conservation success story plays out. Once extinct in our isles, England now has the largest known populations of large blue butterflies. Their survival relies on a game of deception with red ants, which are tricked into adopting the butterfly’s unassuming but predatory caterpillars.
Our story then journeys to the mountains. Each morning in early spring, feisty male black grouse battle for prime position on their frozen breeding grounds. Their sole mission is to impress a female. Meanwhile, on south-facing scree slopes, dozens of adders emerge from hibernation to perform a surprisingly delicate courtship routine.
The episode concludes with a mighty battle in the wild mountains of County Kerry. This is the scene of an epic and spectacular rut between the largest land mammals in Britain and Ireland, red deer.
The grasslands of Britain and Ireland are under threat. We have lost 97 per cent of our species-rich meadows in the last century, as modern agriculture replaces these precious habitats. This episode shows just how important different types of grassland are to the species which call these islands home.

It's a natural history epic. It's a compelling detective story. It's a scientific adventure at its best. It took Dr Fred Urquhart almost 40 years to discover the monarch butterflies' secret hideaway and prove the most incredible migration on Earth. Following the year-long annual migration cycle of the butterflies, the award-winning production team filmed hundreds of millions of monarchs in their remote overwintering sanctuaries in Mexico in 2011 and again in 2012 and also along their migratory routes from Canada, across the U.S. and into Mexico. The film immerses you in the astounding migration experience as two generations of the butterflies migrate north and then a Super Generation miraculously finds its way from Canada to a few isolated mountaintops in Mexico.

There are 200 million insects for each of us. They are the most successful animal group ever. Their key is an armoured covering that takes on almost any shape. Darwin's stag beetle fights in the tree tops with huge curved jaws. The camera flies with millions of monarch butterflies which migrate 2000 miles, navigating by the sun. Super slow motion shows a bombardier beetle firing boiling liquid at enemies through a rotating nozzle. A honey bee army stings a raiding bear into submission. Grass cutter ants march like a Roman army, harvesting grass they cannot actually eat. They cultivate a fungus that breaks the grass down for them. Their giant colony is the closest thing in nature to the complexity of a human city.

As the early June sun begins to set over a calm river in Central Hungary, masses of ghostly shapes emerge from their larval cases to take to the air for the first time. They are mayflies and in a spectacular display, thousands of them demonstrate how the very first wings were used. From the stunning aerobatics of hoverflies in an English garden to the mass migration of purple crow butterflies in the valleys of Taiwan, this episode tells the tale of the first animals ever to take to the air. Unique footage reveals the lightning fast reactions of bluebottles and hoverflies, filmed with one of the world's fastest cameras, and Sir David Attenborough handles the world's largest (and perhaps most ferocious) insect - the Titan beetle.