Watch Planet Earth

In this final stunning episode, a 30 ton whale shark gorges on a school of fish and the unique overhead heli-gimbal camera reveals common dolphins rocketing at more than 30km an hour. Descending into the abyss, deep sea octopus fly with wings and vampire squid use bioluminescence to create an extraordinary colour display. The first ever time-lapse footage taken from 2,000m down captures eels, crabs and giant isopods eating a carcass, completely consuming it within three hours.

Discover the Taiga forest, on the edge of the Arctic - a silent world of stunted conifers. A third of all trees on Earth grow here and during the short summer they produce enough oxygen to change the atmosphere. In California General Sherman, a giant sequoia, is the largest living thing on the planet, ten times the size of a blue whale. The oldest organisms alive are bristlecone pines. At more than 4,000 years old they pre-date the pyramids.

A humpback whale mother and calf embark on an epic journey from tropical coral paradises to storm ravaged polar seas. Newly discovered coral reefs in Indonesia reveal head-butting pygmy seahorses, flashing 'electric' clams and bands of sea kraits, 30-strong, which hunt in packs. Elsewhere plagues of sea urchins fell forests of giant kelp. Huge bull fur seals attack king penguins, who despite their weight disadvantage, put up a spirited defence.

Jungles cover roughly three per cent of our planet yet contain 50 per cent of the world's species. High-definition cameras enable unprecedented views of animals living on the dark jungle floor. In the Ngogo forest the largest chimpanzee group in the world defends its territory from neighbouring groups. Other jungle specialists include parasitic fungi which infiltrate an insect host, feed on it, and then burst out of its body.

After filming for three years, Planet Earth finally captures the shy Mongolian gazelle. Only a handful of people have witnessed its annual migration. Don't miss the bizarre-looking Tibetan fox, captured on film for the first time. Over six weeks the team follow a pride of 30 lions as they attempt to hunt elephants. Using the latest night vision equipment, the crew film the chaotic battles that ensue at close quarters.

The Arctic and Antarctic experience the most extreme seasons on Earth. Time-lapse cameras watch a colony of emperor penguins, transforming them into a single organism. The film reveals new science about the dynamics of emperor penguin behaviour. In the north, unique aerial images show a polar bear swimming more than 100km. Diving for up to two minutes at a time. The exhausted polar bear later attacks a herd of walrus in a true clash of the Titans.

Around 30% of the land's surface is desert, the most varied of our ecosystems despite the lack of rain. In the Gobi Desert, rare Bactrian camels get moisture from the snow. In the Atacama, guanacos survive by licking dew off cactus spines. The brief blooming of Death Valley triggers a plague of locusts 65km wide and 160km long. A unique aerial voyage over the Namibian desert reveals elephants on a long trek for food and desert lions searching for wandering oryx.

Follow the descent of rivers from their mountain sources to the sea. Watch spectacular waterfalls, fly inside the Grand Canyon and explore the wildlife in the world's deepest lake. Planet Earth captures unique and dramatic moments of animal behaviour: a showdown between smooth-coated otters and mugger crocodiles; deep-diving long tailed macaques; massive flocks of snow geese on the wing and a piranha frenzy in the perilous waters of the world's largest wetland.

Tour the mightiest mountain ranges, starting with the birth of a mountain at one of the lowest places on Earth and ending at the summit of Everest. One of Earth's rarest phenomena is a lava lake that has been erupting for over 100 years. The same forces built the Simian Mountains where troops of gelada baboons live, nearly a thousand strong. The program also brings us astounding images of a snow leopard hunting on the Pakistan peaks, a world first.

In this never before seen footage, you will be amazed at the world in its beautiful natural state. The wonder will make you tremble and the beauty will make you fall in love with Planet Earth. Going from tundra to plains, from mountains to ocean, from pole to pole, this episode goes through the features of the show and gives the viewer an outline of what is to come in the future episodes_4-18.