The Harsh Reality For Polar Bears in Arctic (Animal Documentary)

It's early March in the high Arctic. It's still 40 degrees below zero, but now a watery sun brings four months of darkness to an end. A polar bear makes his way down to the coast. Weighing at least 400 kilos, he's the largest land carnivore on Earth. Over the winter, steep hillsides and gullies have gradually become rounded by drifts of snow, often as much as two meters deep. At this time of year, the snows reveal a hidden secret. A female polar bear gazes into this ice-bound world for the first time as she emerges from five months' incarceration beneath the snow. She sniffs the air for danger. She begins to pile up snow around the entrance. No one is quite sure why polar bears do this. But she is not alone. This is the first time her two cubs have left the warmth of the den and felt the bite of the outside air. The fur on her lower chest has become stained yellow by the milk she's suckled her cubs on during the months underground. Released from the confines of their icy prison, the cubs are eager to stretch and play. The pregnant female retreated into her den beneath the snow in early November, and a few weeks later, while winds raged outside, she gave birth in the warmth of her lair. The den consists of several chambers. Without feeding herself, she managed to suckle her cubs throughout the dark months of winter. The walls of the den are covered by scratch marks left by her claws as she carved out the hollow in the snow. By now, the cubs are already four months old and weigh about 11 kilos. The first time they leave the den, they spend only a few minutes outside. The nervous mother tries to summon them back towards the den, but the cubs are loathe to exchange their white playground for the darkness of their winter home. At last, she manages to gather her unruly offspring together. But getting back inside the den is even harder than climbing out. The narrow entrance tunnel is a tight squeeze. Inside the living chamber, all three are tightly pressed together for warmth. On the mountain slopes, the female is spending more time outside the den. She suckles her cubs above ground on milk which is so rich in fat, it's more like cream. She remains beside the den for a couple of weeks, allowing her cubs to become acclimatised to the biting cold. During the five months she spent beneath the snow, the female has lost almost half her body weight. She's now desperate to hunt, but these last few days spent close to the den are vital to allow the cubs time to build up energy reserves. A few other creatures have braved the winter squalls and blizzards. Arctic foxes sniff beneath the snow to seek out any traces of kills made by bears. They are still in their full winter coats. After two weeks at the den, it's time to leave. Hunger drives her on towards the sea ice. In spring, wind and sea currents repeatedly split the solid sheet of land-fast ice into slabs which collide, forming jumbles of ice. The ridged surface of giant glaciers which border the sea remain unchanged. Seals move close to shore to give birth to their pups in chambers beneath the snow. The last thing many newborn seal pups see is the huge paw of a polar bear smashing through the roof of their lair. This male has spent all winter roaming the ice wastes alone, hunting adult seals when they come to their breathing holes for air. The white coat pup is a welcome meal. Only a few weeks old, it's relatively easy to catch. At this time of year, newborn seals provide a vital source of sustenance for polar bears. The male concentrates on wolfing down the energy-rich skin and blubber. Hunger satisfied, he excavates a comfortable sleeping hole in the snow. With no predators, polar bears can afford to be off their guard and relax, even in broad daylight. Sleeping conserves energy, and polar bears spend a lot of time doing just that. Another female leads her two cubs down to the shore. Born the previous spring, both are still completely dependent on her for food and protection from aggressive males. Males will occasionally attack young bears, so this female is determined to stay out of his way. Polar bears are nomadic. They may cover as much as 1,000 kilometres of land and frozen sea each year on their continual search for prey. The female decides it's best to take no chances and makes off into the distance. Long before the snows have begun to melt, migratory birds return to the Arctic. Little orcs arrive in their thousands to establish breeding territories on the rocky slopes. Snow buntings feed on sparse seeds scattered by the wind and lodged in the snow. Across the Arctic Circle with the coming of spring, bears are on the move. A mother with two one-year-old cubs stops to give them a chance to rest and suckle from her. A sudden squall of snow makes the going harder, especially for the cubs, as they head into the wind. They try to stay as close to their mother as possible, though one seems to lag further and further behind. Every so often the female pauses to allow the trailing cub to catch up. When she rolls in the snow, the cubs do the same. This time, when she gets up to leave, the second cub seems to be unable to struggle to its feet. As the blizzard intensifies, the family lies down in the snow to seek shelter from the biting wind. The snow covering the bears' bodies indicates just how efficient an insulator their fur is, trapping all their body warmth close to the skin so that none escapes to melt the snow as it lands on their fur. The second cub hasn't fared so well. Lying just a few metres away from its mother, the sick cub has become almost buried beneath the snow and is now barely alive. She tries to rouse it, but gets no response. The cub is obviously too ill to continue any further. As the blizzard clears, the female spots a male in the distance, slowly approaching the family group. She moves towards him in an attempt to scare him away from the place where her dying cub is lying. But he still lingers nearby. Frantically, she returns to dig her frozen cub from the snow. But it's too late. In the end, she and her surviving cub are driven away from the tiny corpse. She still puts up one last valiant defence. But it's no use. Like so many polar bears who lose cubs to sickness, starvation or injury, she's now left with only one cub to bring up to independence the following spring. The male remains behind to feed on the corpse. Though it's been known for a long time that adult males attack young bears, it was only recently discovered that polar bears are cannibals. By July in the Arctic, the land has become a tapestry of mosses and new grass shoots. The ice and snow transformed into meltwater streams. The bear rocks are quilted with Arctic flowers. Towering 150 metres above the shore are steep, rocky cliffs. Here, huddled together on the narrow ledges, gillimoths have set up breeding colonies high on the steep cliffs that fringe the shore. The narrow shelves are crowded and competition is intense. At all costs, they must nest at a great height and as close to the sea as possible. The survival of their chicks will depend on this. The orcs are becoming restless. Their chicks stand nervously on the cliff edge. There is only one way off. Down. One chick takes a leap into the void. Immediately, its parents launch themselves into the air, stalling to ensure that they remain close beside their chick, barely managing to glide on its tiny, outstretched wings. One by one, other chicks take the plunge, each accompanied by anxious parents. One chick has landed far inland. Its parents have missed its departure and it will have to reach the sea alone. Hardly a match for these powerful skewers, the tiny chick somehow manages to fight the birds off. Then it's forever downwards. The chick seems to be made of rubber, and though exhausted by its rapid and bumpy descent, it's unharmed as it finally reaches the water. It now becomes clear why it's so vital that each chick is accompanied by its parents at the precise instant that it hits the water. Pink-footed geese have laid eggs on a rocky outcrop. Eggs are an important source of food for the Arctic fox at this time of year. But the geese are equal to the battle. Summer in the Arctic is all too brief. As temperatures fall, females and their cubs will spend the winter patrolling the snows. In the most severe storms they make temporary shelters in the snow. Only pregnant females den throughout the winter months. The ice bears move about in the snowfields in perpetual darkness, like great galleons out in a sea storm. Only the moon casts a diffuse light on cloudless nights, and occasionally the aurora borealis, the northern lights, illuminates the cold world below. It's spring once more, and a mother takes her two-year-old cub down to the shore to teach him one of the most important lessons of his life, how to hunt seals. Deep in the frozen inlets where the glaciers meet the sea ice, ringed seals congregate and haul out to bask in the spring sun. But they're nervous creatures, always alert for polar bear attacks. At the slightest sound of creaking ice, they slip through their breathing holes to safety. Beneath the ice the water is insulated from the worst of the cold and never freezes. A female seal only leaves her newborn pup alone in its snow lair beside her breathing hole when she has to feed. Out on the sea ice, the mother and her cub are hunting. Their sense of smell is astonishing. A polar bear can pick up the scent of a dead seal from several kilometres away. She moves purposefully across the melting ice, signaling him to follow. But he hangs back and playfully snatches a mouthful of snow. Polar bears obtain most of their fresh water not from snow, but from the breakdown of fat in their bodies. She's heading towards the jumble of ice beneath the glacier's tongue, a likely place for ringed seal lairs. The young bear has learnt about the changing nature of ice as he followed his mother over the last two years, the longest time polar bears ever spend together. But he cannot expect to remain with his mother much longer. This may be the last chance he will have to benefit from her experience and hunting skills. The cub can smell the seal pup beneath the snow, but he's too late. His mother has already made the kill. For the moment, he will share it with her. Arctic foxes make a habit of following the tracks of polar bears in the hope that some scrap or other will come their way. But often, there are few pickings to be had once the bears have finished with the carcass. Even in April, the weather is fickle, and in just a few minutes, the landscape can vanish beneath a blizzard of snow. Adult bears tend to avoid each other, apart from in the spring when males seek out receptive females. Approached by a young male, the mother is wary. She has good reason to be nervous. He may be more interested in attacking her cub for food than viewing her as a potential mate. The adults circle each other. A male will follow a female for a couple of weeks until she's ready to mate, but this young male is too immature to have much chance of success. The female is interested, but is torn between the need to mate and loyalty to her older offspring. The cub keeps his distance. At two years, he's on the verge of independence. The mother retreats back to protect him, and the male heads off alone. Rocked by the ocean's swell, the layer of ice which has united land and sea is beginning to crack. The spring break-up has begun once more. Within a couple of weeks, the two-year-old is alone. His mother has finally left him to seek out a new mate. Now he'll have to put into practice all that he's learnt, or he will starve. But it's not easy. Even an adult polar bear is rarely successful. It's thought that less than one in 50 hunting attempts ends in a kill. He can smell the seal lair beneath the snow. He waits for the pup to return. This one is empty. Earlier in the year, the newborn pups would have been trapped in the lair, unable to escape into the water until they'd built up an insulating layer of fat. Now they're older, the seal pups can slip silently into the water, long before the young bear breaks through the tough roof. Every attempt he makes is fruitless. At every lair he stands motionless, listening for movement beneath the snow before pouncing. But he's left it too late. Everywhere the land-fast ice is melting, and most of the ringed seal pups have left their lairs. If he's to stand any chance of finding food, he will have to follow the ice and the prey. By May, the sea ice has begun to retreat, leaving a clear expanse of open water for the first time. Throughout the Arctic, the polar ice cap retreats by as much as 50% during the course of the summer. Global warming may be accelerating this shrinkage, having unforeseen consequences for all Arctic wildlife, including its top predator, the polar bear. What ice remains is tearing apart, creating an expanse of floating ice plates. Spring breezes blow the loose blocks out to sea. The flows are the domain of bearded seals. These enormous mammals reach a weight of 350 kilos on a rich diet of shellfish. The bearded seal gets its name from its enormous stiff whiskers. These sensitive hairs are used to feel for food on the bottom. Unlike ringed seals, bearded seals breed on the isolated ice flows rather than landlocked ice. This makes it harder for bears to reach them without warning. The pups need to feed on their mother's rich milk in order to build up their fat layer. But for the first few days after birth, their thick fur helps keep them warm. Unfortunately, some females choose ice blocks which remain fused to the land. This three-day-old pup has been born in a dangerous place. Its mother remains nearby, keeping a watchful eye. A hungry young bear is attracted by the smell. But he has been far too obvious in his approach. Unlike ringed seal pups, the bearded seals are sufficiently well insulated with fat to allow them to enter the water only a day or so after birth. Polar bears are not above scavenging. He comes across the blood-spattered evidence of another polar bear's successful attack on a seal lair. But the remains of the seal have been removed from the site of the kill. He's not the only guest at the feast. Ivory and glaucus gulls pick over the bones. Meticulously, he tears every morsel of flesh from the gaunt ribs. Though this will sustain him for a while, he needs the fat-rich blubber of a fresh kill. Polar bears are able to survive for up to nine months on their fat reserves. During hard times, they switch their body into an energy-conserving state. But spring is the time when they build up their fat reserves for the winter. It's quite common for an adult polar bear to walk 100 kilometres in order to achieve one successful seal predation. The Arctic fox is equally desperate for food. It's still too early for bird eggs, and he has a family to feed. Patches of brown summer coat are already visible beneath his molting winter pelt. He grabs both seal flippers and makes off towards his den with his booty. Far out to sea, old fjord ice drifts on the currents. All the seals are now on free-floating icebergs like these. In places, fox and bear tracks still remain on the surface, all that's left to portray its origins. Ancient glaciers cover vast areas of the Arctic. They creep across the land, moving imperceptibly downhill towards the sea. But some glaciers surge rapidly, moving a few metres each day. For many animals and birds, the open water creates ideal feeding conditions. But for the polar bears, open water provides no food at all. For seals need ice, and polar bears need seals. This is when polar bears reveal unexpected skills. They can dive and swim well, and can even launch a deadly attack on swimming seals. They are really sea bears, buoyed up by the thick layer of fat, and well-adapted to paddle with their front feet. They can reach speeds of five kilometres an hour, and they have been known to swim a hundred kilometres non-stop. An adult female has killed a seal hauled out on an iceberg. Seals are insulated by a layer of blubber up to ten centimetres thick. It's this that makes an adult seal so attractive to a hungry polar bear. The young male picks up the scent of the fresh kill. As the hunter is a female, he will try to fight for a share if he can. He wouldn't risk it with a larger male. He swims silently towards the feeding female. She stands guard over the carcass, but there is no way she can defend her kill from a much stronger male. Even so, as he helps himself to the carcass, a tug-of-war develops over the prized skin and blubber. But there's plenty to share around. Unlike other bears, polar bears are truly carnivorous, with powerful flesh-shearing incisors. A male may eat as much as 10% of his body weight in under half an hour. Now the darkness of winter is replaced by the midnight sun, which hardly dips beneath the horizon, even at night. The summer is short-lived. All too soon, clouds block the sun and the first blizzards of autumn begin. The young bear is not put out by the cold, for the white fur is hollow, directing the rays of the sun down towards the black skin, which quickly absorbs what little warmth there is to be had. If he survives this first winter on his own, his chances are high. As the temperature falls, the water begins to thicken. By November, the sun hugs closer and closer to the horizon, until it sinks beneath the snows for the last time. It will not be seen again for the next four months.