Back one million years ago, South America was a continent of exotic oversized creatures found nowhere else on Earth - huge terror birds, giant ground sloths and spiky-tailed relatives of the armadillo as big as cars. The deadliest animal of them all was smilodon, the largest of the sabre-tooth cats, with canines like carving knives. The programme follows the fortunes of an individual male, Half Tooth. Ousted from his clan by a pair of rival males, his life suddenly becomes a struggle to survive in this alien world.

The natural world is full of colours. For us, they are a source of beauty, but for animals they are a tool for survival. David Attenborough reveals the extraordinary ways in which animals use colour: to win a mate, to fight off rivals and to warn enemies. New camera technologies - some developed especially for this series – also allow us to see colours and patterns usually invisible to human eyes.
Ultraviolet cameras reveal bright signals on a butterfly’s wings and facial markings on yellow damselfish that are used as secret communication channels. Some animals can also detect polarized light, and specialist cameras can now show us how fiddler crabs see the world, and how mantis shrimp have strange polarization patterns on their bodies to signal to a mate or rival.

David Attenborough concludes his epic history of the evolution of flight with an exploration of the highly advanced fliers that dominate our skies today – the extraordinarily diverse skills of the birds, and the sonar-guided precision of the bats. He encounters some of our planet’s most remarkable fliers – from peregrine falcons dive-bombing starlings over Rome, to hummingbirds hovering in the cloud forests of Ecuador. In a spectacular finale, he visits Gomantong cave in Borneo to witness the mass exodus of a million bats.

In the past few decades, scientists have learned that the basis of everything they thought they knew about bird brains—that they were largely comprised of the most primitive and instinctual of brain structures—was wrong. Fully 75 percent of the brains of parrots and thousands of other species of birds is actually made up of a sophisticated information processing system that works much the same way as the locus of human higher-mindedness, the cerebral cortex.
The film shows scientists putting birds to the test. Can they solve problems? Can they cooperate? Do they feel emotion? New research demonstrates just how clever they can be.

A bird's-eye view of some of the world's greatest natural spectacles. Amazing sights from five continents are revealed in a whole new light. Using cutting edge new filming techniques to show everything in exquisite detail, viewers have a uniquely privileged perspective. The first episode takes flight across North America, as a flock of millions of snow geese discover what it is like to be on the hit list of America's national bird: the bald eagle. In California, pelicans reveal devil rays that perform astonishing somersaults and find bizarre grunion fish that wriggle ashore to spawn. In Alaska, bald eagles swoop among brown bears fishing for salmon. And on the Great Plains, cowbirds duck and dive under the feet of fighting bison.

In a late Jurassic forest in what is now China, an Epidexipteryx escapes from a juvenile Sinraptor by climbing a tree. It finds a beetle grub in the tree bark, being shown to use its elongated fingers in a similar way to a modern day aye-aye. However, its prey is stolen by another, larger Epidexipteryx, and after a brief bout of posturing, the smaller individual goes to find more food. It drops a second grub to the forest floor, where the other Epidexipteryx retrieves it, only to be killed by the juvenile Sinraptor. The episode then cuts to a desert in late Cretaceous Mongolia, where a Saurornithoides is shown brooding a nest of eggs. When it leaves the nest, an Oviraptor raids it, fleeing when the troodontid returns. The Saurornithoides is suddenly attacked and eaten by a Gigantoraptor, which then heads to compete in a breeding ritual for mates. The males use their feathers for display, a brief fight between two erupting at one point, allowing the females to choose the best suitor. The episode finally cuts to an early Cretaceous forest in China, where a Xianglong is being hunted by a Microraptor, which uses its feathers to pursue the gliding lizard in the air. A Sinornithosaurus attacks it, and after a brief chase the Microraptor manages a lucky escape. The Sinornithosaurus, alongside two other members of its species is then shown hunting a Jeholosaurus and its three young. The group brings down the parent, the narrator explaining that their possibly venomous bite allowed them to tackle animals much larger than themselves. A montage is then shown of the feathered dinosaurs featured in the programme, with the narrator saying that Microraptor not only hints at how flight might have developed, but also that dinosaurs still live amongst us today, as birds.