Every year, around the world, seasonal changes transform entire landscapes and draw in millions of creatures as these great events unfold. This fantastic series combines the epic scale of Planet Earth and the intimate, emotional stories of charismatic animals as they struggle to survive. Using state of the art technology, these programmes capture the Earth's most dramatic and epic wildlife spectacles and the intimate stories of the animals caught up in them.
The Great Melt: The summer melt of Arctic ice, opening up nearly three million square miles of ocean and land, provides opportunities for millions of animals, including beluga whales, families of Arctic foxes, vast colonies of seabirds, and the fabled Arctic unicorn, the narwhal. For polar bears, however, it is the toughest time of year. Why? How will they survive? A mother polar bear and her cub make their first journey together onto the sea ice. They are looking for ringed seals, their favourite prey. It is a serious business but the cub just wants to play. The melting ice makes it harder for them to hunt and threatens their survival. In a unique aerial sequence, the migration of narwhal with their distinctive unicorn-like tusks is filmed for the first time. The whales' journey is risky as they travel along giant cracks in the ice. If the ice were to close above them, they would drown. Hundreds of beluga whales gather in the river shallows. They rub themselves on smooth pebbles in one of the most bizarre summer spectacles. Guillemot chicks take their first flights from precipitous sea cliff nests to the sea 300 metres below. They attempt to glide to safety but many miss their target. Their loss is a bonus for the hungry Arctic fox family waiting below. As the melt comes to an end the bears gather, waiting for the sea to freeze again. Two 400kg males square up to each other to spar.

Mathematician Dr Hannah Fry explores the mystery of maths. It underpins so much of our modern world that it's hard to imagine life without its technological advances, but where exactly does maths come from? Is it invented like a language or is it something discovered and part of the fabric of the universe? It's a question that some of the most eminent mathematical minds have been wrestling with. To investigate this question, Hannah goes head first down the fastest zip wire in the world to learn more about Newton's law of gravity, she paraglides to understand where the theory of maths and its practice application collide, and she travels to infinity and beyond to discover that some infinities are bigger than others.
In this episode, Hannah goes back to the time of the ancient Greeks to find out why they were so fascinated by the connection between beautiful music and maths. The patterns our ancestors found in music are all around us, from the way a sunflower stores its seeds to the number of petals in a flower. Even the shapes of some of the smallest structures in nature, such as viruses, seem to follow the rules of maths. All strong evidence for maths being discovered. But there are those who claim maths is all in our heads and something we invented. To find out if this is true, Hannah has her brain scanned. It turns out there is a place in all our brains where we do maths, but that doesn't prove its invented.
Experiments with infants, who have never had a maths lesson in their lives, suggests we all come hardwired to do maths. Far from being a creation of the human mind, this is evidence for maths being something we discover. Then along comes the invention of zero to help make counting more convenient and the creation of imaginary numbers, and the balance is tilted in the direction of maths being something we invented. The question of whether maths is invented or discovered just got a whole lot more difficult to answer

The Series 'In Search of' conducted investigations into the controversial, paranormal and mysterious. The producer's purpose is to suggest some possible explanations, but not necessarily the only ones, to the mysteries examined. The 2018 revival is presented by Zachary Quinto.
In this episode, Zach wants to understand how a person can be superhuman. He meets a man who bent the metal frame of a car door with his bare hands in a moment of crisis; a man who can feel no pain; and a Shaolin warrior monk, who teaches him how to harness superhuman powers of his own.

Francisco de Orellana failed to find El Dorado, but discovered the Amazon. Early in 1541, a rumor swept Quito that beyond the mountains, there lay a land richer than Mexico, or even Peru - a land of gold. The ruler of this land was so rich that he covered himself with gold dust every day and washed it off every evening. He was "the golden man", El Dorado. They had tree goals: to find La Canela, the land of cinnamon: to assess new lands for colonization; and to find El Dorado. On march 1541, They marched eastwards with more that 200 Spanish troops and thousands of native servants.

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.

Plants' solutions to life's challenges are as ingenious and manipulative as any animal's. Innovative time-lapse photography opens up a parallel world where plants act like fly-paper, or spring-loaded traps, to catch insects. Vines develop suckers and claws to haul themselves into the rainforest canopy. Every peculiar shape proves to have a clever purpose. The dragon's blood tree is like an upturned umbrella to capture mist and shade its roots. The seed of a Bornean tree has wings so aerodynamic they inspired the design of early gliders. The barrel-shaped desert rose is full of water. The heliconia plant even enslaves a humming bird and turns it into an addict for its nectar.