Be it foxes on city streets or wolves on the tundra, canines rely on sharp senses, athleticism and fierce determination to punch above their weight. But the real secret of their success is much more surprising. It's a story of their intimate side. It's what makes every dog, from pet pooch to wild dogs, one of the family.

In the far north of our planet lies the largest land habitat on earth, home to snow-covered forests and the icy open tundra. These are lands of extremes that push animals to their limits: in winter they are so cold that much of the ground has remained frozen since the last ice age. To stand any chance of survival, animals must adapt in extreme ways: here a super pack of wolves, 25 strong, has come together to take on the only large prey available to them in winter, American bison.
On the featureless tundra, an Arctic fox must strike a living alone. She is a wanderer and will roam many hundreds of miles searching for tiny lemmings, hidden deep underground. The only way to reach them is with a head dive. In the remote far east of Russia, a rare Amur leopard prowls the seemingly empty, snow-covered forest. With little prey available, it must use its ingenuity to find a meal. It follows crows in the hope of finding carrion, but it must not stay long, for it shares the forest with a far larger but equally hungry big cat, the Siberian tiger.
As spring arrives, the forests begin to thaw and life returns. Beneath the ground, a nest of tiny painted turtle hatchlings now emerge, having remained frozen in a state of suspended animation throughout winter. To the north, it is a further month before the sun’s warmth baths the frozen ground of the tundra. Tucked away underground lies a tiny snow queen – a Lapland bumble bee. She is the sole survivor of her colony - the rest perished in the winter freeze - but her larger size, her furry body and antifreeze in her blood have allowed her to survive. Now she is in a hurry. She must feed herself and raise a brood in the brief window of summer while the flowers are in bloom.
Snowy owls also use the open tundra to breed: one pair have raised a nest full of fluffy chicks. With 24-hour daylight in which to hunt, the dedicated parents bring back meal after meal for their ever-growing brood. But one day, they return to find the nest empty.
Today, the biggest challenge in the tundra is climate change. Warming summers are melting the permafrost deep within the soil, causing the ground to thaw and, in places, the land to collapse. These changes are impacting the animals too. Caribou arrive in herds of 200,000 individuals to raise their calves in the rich pastures, but warming means mosquitos emerge sooner and bother the calves before they have had a chance to gain strength. The parents drive their young to cooler, mosquito-free land, but to get there they must cross rivers running with increased meltwater and escape hungry grizzly bears. They, like much of the tundra's wildlife, are adapted to live in the extremes - but the challenge of today’s warming climate could be one extreme too many.

Journeying from pole to pole, The series 'Frozen Planet II' reveals surprising worlds that exist across the planet and the remarkable animals that make them their home. In a fragile world of beauty and hostility, nature finds a way to survive and thrive. David Attenborough explores a planet on the brink of major change.
In the first episode, we begin our journey in the far south, in the most hostile place on earth, the frozen continent of Antarctica. After being raised on the ice in winter, emperor penguin chicks find themselves abandoned by their parents in spring. To survive, they must find their own way across the treacherous sea ice to the rich waters of the Southern Ocean.
The waters surrounding Antarctica may be the richest of all, but they are also home to an exceptionally sophisticated predator, the killer whale. To reach their favored prey, Weddell seals, a family of killer whales have learnt to generate their own waves, washing the seals off their ice floes. It’s a technique that has been passed down over generations and is coordinated by the family matriarch, who can be over 100 years old.
Leaving Antarctica and travelling north, we discover frozen habitats that are created by altitude. The greatest of these is the Himalaya, the tallest mountain range on earth, which contains so much ice and snow it is known as the third pole. In the shadow of the Himalaya lies a vast frozen grassy plain that is home to the fluffiest cat in the world, Pallas’s cat. It may have extremely dense fur, but if it’s to survive the Mongolian winter, it needs to catch lots of gerbils and voles. Easier said than done when you only have short legs and paws that are sensitive to the cold.
North of the Great Steppe lies the boreal forest, which encircles the continents of North America, Europe and Asia, and remains frozen for six months of the year. Prowling these forests in the far east of Russia is the Siberian tiger, the largest cat in the world. In winter, it is on the lookout for black bears hibernating in caves, a high-risk strategy that only a cat of this size would attempt.
Above the boreal forest, we cross into the Arctic Circle, where conditions become so extreme that trees can no longer grow. This is the tundra. Living here are relics of the last ice age, musk ox. In spring, their calves face a far greater danger than the cold, grizzly bears. Encounters can be brutal, but if just a few calves survive the gauntlet, the herd’s future is secure.
To the north of the tundra is the Arctic Ocean, the only ocean that can completely freeze over. Living here is one of the most peculiar animals on earth, the hooded seal. Males have extraordinary inflatable noses, producing a bright red balloon out of their left nostrils. One male hopes this will make him irresistible.
All of the frozen habitats share one thing in common: the threat posed by today’s climate change. Travelling to the island of Greenland, home to the largest body of ice in the northern hemisphere, we witness how global warming is melting its ice cap at faster rates than ever before, with profound consequences for global sea levels. Lastly, we visit the Arctic’s most iconic resident, the polar bear, as a mother bear struggles to provide for her cubs in a world of shrinking sea ice.

For the animals in the polar regions, autumn means dramatic battles and epic journeys. Time is running out - the Arctic Ocean is freezing over and the sea ice is advancing at 2.5 miles per day around Antarctica. Polar bears gather in large numbers on the Arctic coast as they wait for the return of the ice. Soon, tempers fray and violent sparring contests break out. Meanwhile 2,000 beluga whales head for one special estuary, a gigantic 'whale spa' where they will thrash their snow-white bodies against the gravel and exfoliate. Inland, the tundra undergoes a dramatic transformation from green to fiery red. Here, musk ox males slam head-first into each other with the force of a 30mph car crash as they struggle to defend their harems. Frisky young caribou males play a game of 'grandma's footsteps' as they try to steal the boss's female. Down in Antarctica, Adelie penguin chicks huddle together in creches. When a parent returns from fishing, it leads its twins on a comical steeplechase - sadly there's only enough for one, so the winner gets the meal. Two months later and the chicks are fully feathered apart from downy Mohican hairdos - they're ready to take their first swim - reluctantly though, as it seems penguins are not born with a love of water! And with good reason - a leopard seal explodes from the sea and pulls one from an ice floe, a hunting manoeuvre that has never been filmed before. As winter approaches and everyone has left, the giant emperor penguin arrives and makes an epic trek inland to breed. The mothers soon return to the sea leaving the fathers to hold the eggs and endure the coldest winter on earth.

It is high summer in the Polar Regions, and the sun never sets. Vast hordes of summer visitors cram a lifetime of drama into one long, magical day; they must feed, fight and rear their young in this brief window of plenty. Summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson. Some bears save energy by dozing on icy sun beds, while others go egg-collecting in an Arctic tern colony, braving bombardment by sharp beaks. There are even bigger battles on the tundra; a herd of musk oxen gallop to the rescue as a calf is caught in a life and death struggle with a pair of Arctic wolves. But summer also brings surprises, as a huge colony of 400,000 king penguins cope with an unlikely problem - heat. The adults go surfing, while the woolly-coated chicks take a cooling mud bath. Nearby, a bull fur seal is prepared to fight to the death with a rival. Fur flies as the little pups struggle desperately to keep out of the way of the duelling giants. Further south, a minke whale is hunted amongst the ice floes by a family of killer whales. The dramatic chase lasts over 2 hours and has never been filmed before. The killers harry the minke whale, taking it in turns to wear it down. Eventually it succumbs to the relentless battering. Finally, comical adelie penguins waddle back to their half a million strong colony like clockwork toys. The fluffy chicks need constant feeding and protection as piratical skuas patrol the skies. When an unguarded chick is snatched, a dramatic "dogfight" ensues.

The documentary series reveals the extraordinary riches and wonders of the Polar Regions that have kept people visiting them for thousands of years. Today, their survival relies on a combination of ancient wisdom and cutting-edge science. Most Arctic people live in Siberia, either in cities like Norilsk - the coldest city on earth - or out on the tundra, where tribes like the Dogan survive by herding reindeer, using them to drag their homes behind them. On the coast, traditional people still hunt walrus from open boats - it is dangerous work, but one big walrus will feed a family for weeks. Settlers are drawn to the Arctic by its abundant minerals; the Danish Armed Forces maintain their claim to Greenland's mineral wealth with an epic dog sled patrol, covering 2,000 miles through the winter. Above, the spectacular northern lights can disrupt power supplies so scientists monitor it constantly, firing rockets into it to release a cloud of glowing smoke 100 kilometres high. In contrast, Antarctica is so remote and cold that it was only a century ago that the first people explored the continent. Captain Scott's hut still stands as a memorial to these men. Science is now the only significant human activity allowed; robot submarines are sent deep beneath the ice in search of new life-forms, which may also be found in a labyrinth of ice caves high up on an active volcano. Above, colossal balloons are launched into the purest air on earth to detect cosmic rays. At the South Pole there is a research base designed to withstand the world's most extreme winters. Cut off from the outside world for six months, the base is totally self-sufficient, even boasting a greenhouse.