Canada -
the second largest country on Earth.
Famous for its epic wilderness.
From the Rocky Mountains...
..to the Great White North.
Breathtaking...
..rugged...
..and immense.
It's a rich and varied wonderland
which supports some of North America's most iconic species.
Theirs is a world of extremes.
Their life at the mercy of the elements.
Every season brings new challenges.
It'll take strength and tenacity...
..courage and resilience...
..skill and good fortune...
..just to make it through A Year in the Wild.
December.
Days are at their shortest.
With less sunlight, temperatures start to plummet...
..transforming both land...
..and sea.
Surviving the next few months will test every nerve and sinew.
In Canada's east lies Hudson Bay...
..a vast body of water twice the size of France.
On the bay's western shore, near the town of Churchill,
a male polar bear is restless.
Half-starved, having not eaten for five months,
he is waiting for winter to deliver salvation.
When the sea freezes over, he can head out onto the ice to hunt seals.
He's not alone.
Polar bears are gathering from miles around.
They know that this western section of the Hudson Bay
is normally the first to freeze, allowing them to hunt earlier.
But, this year, the ice has been slow to form...
..denying them access to a vital meal.
Seals are also waiting for the sea ice to form,
so they can haul out and give birth.
Both must wait.
The ice can only form once the sea temperature is low enough.
It starts with pancakes of ice...
..which grow...
..and gather.
Driven by winds and waves,
they pack together to create a platform several feet thick.
But, this year, southerly winds are keeping the ice way out at sea...
..and the seals many miles off shore.
He doesn't have the energy for a long swim,
so is trapped on the land, slowly starving.
To save energy, he's been doing very little.
Now, it's time to stretch tendons and flex muscles...
..so that he's nimble enough once the ice returns.
If it doesn't come soon, he won't survive the winter.
50 miles inland from the bears,
in a traditional polar bear denning area,
a pregnant female is about to start hibernating.
She's hardly eaten since summer and must now lock herself away
in a snow cave to give birth.
When she next sees the sun, in February,
she'll have her cubs in tow.
Together, they'll start the long and treacherous walk to the coast,
so they, too, can take advantage of the bounty brought by the sea ice.
But that is still three months off.
Ahead lies one of the most brutal winters on the planet.
To survive out here is tough.
Only the best adapted will make it through.
One Arctic specialist relies on its camouflage
but must also stay low if it's to avoid catching the eye of predators.
It's December on Canada's Hudson Bay.
An arctic blast drives the temperature down
to -30 degrees Celsius.
Most animals hunker down on days like this.
Not ptarmigan.
They face the arctic winter head on.
To survive each bitterly cold night, they must keep eating.
Back in the autumn, the ptarmigan's brown and black plumage
helped them blend in with the tundra vegetation
so they could hide from predators like this red fox.
As autumn ended, they started to moult, growing new white feathers,
making them invisible in the snow.
Feathery feet allow them to move swiftly over soft snow,
and their camouflage keeps them well hidden,
but only if they stay on the ground.
They eke a meagre living from willow twigs and buds.
But staying warm out here burns calories.
For ptarmigan, it's a day-to-day existence.
As evening approaches,
they head higher up the willows, where buds are more tightly packed.
Up here, they stand out,
drawing the attention of a hungry young snowy owl.
Ptarmigan are not her usual prey, but she's desperate.
Keen eyes help her detect the slightest movement.
She locks on.
With a five-foot wingspan, she prefers to hunt in the open.
She hugs the ground to avoid detection.
But ptarmigan work together and, when danger is spotted...
..the whole flock heads for cover.
If this snowy owl is to survive the winter,
she must hone her hunting skills.
As for the ptarmigan, they must hope they've eaten enough
to see them through the long night ahead.
A quarter of Canada is covered in forest.
It spans the entire continent, from Yukon in the west,
to Newfoundland in the east.
This is the boreal forest,
a belt of trees dominated by conifers.
90% of birds that spent summer here have left for warmer climes
and now the forests are silent.
The tracks of an inquisitive fox...
..and a wisp of warm air...
..reveal a beaver lodge.
Beavers maintain their lodges year-round.
Come winter, it's all that stands between them and certain death,
either from the extreme cold, or predators.
Their pond frozen, they're locked away under the ice.
To survive the winter, they must have stockpiled enough food.
Two months ago, temperatures started to drop.
To help see them through the winter,
the beavers gathered as many green branches as they could...
..and stashed them under the ice.
They tried to keep the pond open...
..but, ultimately, their efforts proved futile.
The ice closed up,
locking the beavers away from fresh food until spring.
Outside, it's like the arctic.
Scavengers search the snowfields,
searching for animals that have succumbed to the cold.
Inside their lodge, the beavers are warm.
Thick walls of mud and wood keep the elements out.
They'll survive, as long as they have stored enough food
and winter doesn't drag on for too long.
900 miles northwest of the beaver lodge,
on the western shore of the Hudson Bay,
lies Wapusk National Park,
where the temperature has dropped to -50 degrees Celsius...
..freezing the snow,
locking away the caribou's food, forcing them to keep searching.
If they're to eat, they must find areas of soft snow
where they can reach the plants and lichens below.
The old and the weak will struggle
and gradually succumb to starvation...
..making them easy prey for wolves...
who follow the caribou herds...
..preying on the vulnerable.
But it's not just the wolves that benefit.
The frozen remains of a kill.
An arctic fox picks what it can from the bones.
Mere morsels, but it's better than nothing.
By following the wolves,
he gets access to food that would otherwise be out of reach.
But he mustn't get too close, or he risks becoming prey himself.
50 miles inland from the Hudson Bay foxes,
the polar bear mother emerges from hibernation.
She checks the coast is clear with her keen sense of smell.
She cleans her fur in the snow.
It's her first stretch since locking herself away three months ago.
Since then, she's given birth...
..to two tiny cubs.
This is one of their first forays into the great outdoors.
Short walks help them build muscle
and familiarise them to their new world.
They usually return to the den but their mother is hungry.
She has not eaten for four months
and has lost almost half her body weight.
She needs what little fat she has left, to make milk for her cubs.
She must walk 50 miles to the coast.
Unless she gets seal meat soon, the whole family will starve.
50 miles south of Canada's Hudson Bay,
an epic journey has begun for two polar bear cubs.
Their mother needs food.
She's lean and hungry, and desperate to go seal hunting.
But the coast is many days away.
She spent the winter inland to keep her cubs safe from male polar bears
who will kill and eat cubs that are not their own.
Her journey is long
and she can only travel as fast as her cubs will allow.
At just three months old, they tire quickly and need regular feeding.
She prepares a temporary nursery at the base of a tree.
Sheltered from the wind, the cubs can play.
Born smaller than a human fist,
these cubs have already piled on 20 lbs
thanks to their mother's fat-rich milk.
But she's running on empty, and must eat soon.
Almost half of all cubs born never see their first birthday,
but she'll do anything to protect her family.
If they can survive this life-or-death journey
towards the sea ice,
there's a good chance they'll spend the next two years together.
Late February.
The sea ice now covers almost 6 million square miles of ocean...
..from the North Pole 2,500 miles along Canada's east coast.
It's the perfect nursery for a quarter of a million harp seal pups.
While their mums are out fishing,
pups hunker down...
..hungry and vulnerable.
With so much sea ice and so many pups to choose from,
it's a wonder the mothers can find their way back.
They read the ice floes like a map...
..and, once close, listen for the cry of their own pup...
..always returning with pinpoint accuracy.
Milk is too precious to waste on the wrong pup
so she double-checks with a sniff, and then lets him feed.
She'll only nurse him until he's 12 days old.
That's when she must leave, find a partner, and breed again.
So, it's essential he grows up fast.
Milk twice as rich as double cream
helps him pile on up to 6 lbs per day.
His development is rapid but it has to be.
Time is against him.
His sea ice nursery is only temporary.
Every day it gets a little thinner.
Melt too soon and it will spell disaster.
Just eight years ago, the sea ice broke up overnight...
..while the pups were too young to swim.
Cast adrift, they were pitched into the sea and washed away by waves.
It's thought that every pup born that year drowned.
So, the sooner they can swim, the better.
His mother tries gently, coaxing him in.
But he's not convinced.
So, she dives out of sight...
..which does the trick.
His first swimming lesson.
He stays close to the surface,
under the watchful eye of his mother.
But he won't stay in for long.
His white baby fur may keep him warm on the ice
but it does little to insulate him in the water.
In a few more weeks, he'll have grown an adult coat
and a thick layer of blubber to keep him warm.
Like all this year's seal pups,
he just needs the sea ice to last a little longer.
March in the boreal forests of south-east Canada.
Late winter snowfall cloaks the conifers.
Their cone shape and bendy branches
help them to cope with heavy snow.
Ten feet of snow falls here annually,
making it hard for animals to move around on the ground.
A young male porcupine
has struggled through five months of brutal winter.
This fresh covering of snow makes life even harder.
He's already used up most of his fat reserves
and must make daily foraging trips if he's to see the spring.
The deep snow has locked away shrubs and grasses,
and most trees have dropped their leaves,
so, he must travel further and for longer to feed.
The more time he's on the ground,
the more exposed he is to predators...
..especially as he's still young and his quills are not yet fully grown.
His only food is high up in the tree canopy.
Powerful, stout legs propel him upwards.
Long claws and leathery footpads provide grip.
He strips off the bark with his powerful incisors
to get to the softer layer beneath.
But it's still only slightly better than eating cardboard.
The outer branches are generally softer and easier to chew...
..but reaching them is risky.
If the branch breaks, he'll plummet to his death.
It's mid-March in Canada's northern forests.
Winter shows no signs of loosening its grip.
Desperate for food,
a young porcupine has scaled 40 feet up a tree to feed on bark.
Birch bark is thin and peels away from the trunk easily.
Getting down is dangerous.
Falling is common.
A study revealed that 30% of porcupines have broken bones.
His broad, flat tail gives him extra grip and acts like a brake.
Back on the ground, he's vulnerable again and still hungry...
..so he heads for a conifer.
Pine needles are toxic to most animals but not to porcupines.
Instead, they're an essential source of nutrients.
As evening falls and the temperature drops,
he puffs up his woolly underfur, trapping warm air next to his body.
After foraging for eight hours...
..it's time to head back to his den...
..where he can digest a belly-full of bark...
..out of the bitter wind and the reach of nocturnal predators...
..who are starting to wake up, and hunt.
On the edge of the forest, a great grey owl surveys her territory.
With a five-foot wingspan and standing two feet tall...
..she's America's largest owl...
..and a formidable predator.
But she's not interested in the porcupine.
She specialises in hunting smaller rodents.
She needs to catch seven every day just to stay alive.
But the rodents are sheltered under the deep snow
to avoid the freezing air.
Tunnels let them creep from sleeping quarters to feeding grounds
without being spotted.
But she's not just looking.
She's listening.
Her facial feathers funnel sound directly into her ears,
helping her pinpoint voles up to 50 metres away,
even under two feet of snow.
Swooping in low and fast...
..she hovers to get a final fix.
But the vole gets away.
She must quickly reset and prepare to hunt again.
Every miss costs her dear...
..especially this year, with winter slow to loosen its grip.
Next time, spring is coming.
Warmer temperatures bring an end to a long and freezing hibernation.
Animals feast after a winter of famine
and the race to raise a family is on.
Subtitles by Red Bee Media