0:00:02 > 0:00:03They call it America's last frontier.
0:00:07 > 0:00:10Half a million square miles of wilderness.
0:00:12 > 0:00:14This is Alaska.
0:00:17 > 0:00:21Home to some of the hardiest animals on the planet.
0:00:27 > 0:00:30Alaskan seasons run fast and furious.
0:00:39 > 0:00:41Opportunities are fleeting...
0:00:43 > 0:00:46..for people as well as animals.
0:00:47 > 0:00:50Survival means making the most of nature's gold rush.
0:00:52 > 0:00:55Play it right and you'll hit the jackpot.
0:00:55 > 0:01:00Get it wrong and you could lose it all.
0:01:03 > 0:01:05It's not about your size.
0:01:05 > 0:01:08It's about your attitude.
0:01:08 > 0:01:10This land belongs to the bold.
0:01:13 > 0:01:15This is Alaska.
0:01:28 > 0:01:31Right up on the northern extremes of the planet.
0:01:34 > 0:01:37A third lies within the Arctic Circle.
0:01:41 > 0:01:43Every season here is intense
0:01:43 > 0:01:47but winter is the one that takes your breath away.
0:01:50 > 0:01:53For six months, it's a wonderland of snow and ice.
0:01:59 > 0:02:03But winter is also a time of bitter cold and desperate hunger.
0:02:11 > 0:02:15Up here they call it 'the great white silence'.
0:02:26 > 0:02:30It's only September but already in the central mountains,
0:02:30 > 0:02:32winter is creeping in.
0:02:34 > 0:02:38The peaks of Denali are the highest in North America.
0:02:38 > 0:02:40Up there, it's always white.
0:02:43 > 0:02:46The lower slopes will soon be buried under meters of snow, too.
0:02:52 > 0:02:55This young Arctic ground squirrel is running late.
0:02:58 > 0:03:02Too small to face winter head-on, first he has to fatten up.
0:03:10 > 0:03:13There's plenty of berries, but not much time.
0:03:15 > 0:03:18He needs to nearly double his body weight
0:03:18 > 0:03:21and he doesn't seem to be taking the job entirely seriously.
0:03:28 > 0:03:32Not only that, now there's a grizzly bear in the way.
0:03:37 > 0:03:40She's also building herself up for winter
0:03:40 > 0:03:43and she'd make short work of a ground squirrel.
0:03:53 > 0:03:58A little piece of shed fur would certainly make his nest warmer.
0:04:11 > 0:04:13Is it worth the gamble?
0:04:25 > 0:04:29Whether you're a great big bear or a little squirrel,
0:04:29 > 0:04:32you have to prepare, and that means taking risks.
0:04:36 > 0:04:39That's how it is in Alaska.
0:04:39 > 0:04:43If you don't take care of yourself, winter will take care of you.
0:04:50 > 0:04:55For a ground squirrel, the way to get through winter is to sleep.
0:04:55 > 0:04:58But this will be no ordinary sleep.
0:04:58 > 0:05:02For the next eight months, he will be barely alive.
0:05:17 > 0:05:18As the air cools,
0:05:18 > 0:05:22his body temperature is already slipping towards freezing,
0:05:22 > 0:05:25shutting down almost every system in his tiny body.
0:05:33 > 0:05:37It's drastic but he really has no choice.
0:05:37 > 0:05:39The big chill is coming.
0:05:54 > 0:05:56With winter nipping at its heels,
0:05:56 > 0:06:00this sandhill crane is high-tailing it south
0:06:00 > 0:06:033,000 miles towards Mexico.
0:06:07 > 0:06:10There are some formidable mountains along its flight path.
0:06:13 > 0:06:17Their next challenge is to get over the Alaska range
0:06:17 > 0:06:21so families join up to make their journey together.
0:06:24 > 0:06:28But before they do, they put down in a barley field to rest and refuel.
0:06:32 > 0:06:36Some are hardened veterans that have passed this way many times before.
0:06:39 > 0:06:42These red-faced adults know better than to linger for long.
0:06:49 > 0:06:51Others are complete rookies.
0:06:54 > 0:06:57Young chicks making their first flight south.
0:07:06 > 0:07:09Birds can sense the smallest changes in air pressure.
0:07:10 > 0:07:12There's a storm coming.
0:07:18 > 0:07:20Winter has caught them out.
0:07:29 > 0:07:30There is nothing they can do
0:07:30 > 0:07:33except fuel up and hope the storm blows through.
0:07:37 > 0:07:39The younger birds, especially,
0:07:39 > 0:07:42don't have the reserves to cope with this for long.
0:07:56 > 0:07:59It's starting to seem like a very long way to sunny Mexico.
0:08:07 > 0:08:10After two days, the storm starts to ease.
0:08:17 > 0:08:20But headwinds keep the birds pinned down.
0:08:26 > 0:08:30The grounded flock has caught the attention of a golden eagle.
0:08:33 > 0:08:37If the storm strengthens again, they could all perish here.
0:08:50 > 0:08:54As the headwinds finally subside, an escape route opens.
0:09:09 > 0:09:11The flock rises on the warming air
0:09:11 > 0:09:15and makes good their escape before the door closes for good.
0:09:35 > 0:09:39Hundreds of thousands of cranes follow this route south every year.
0:09:54 > 0:09:58Alaska is more than 1,400 miles from north to south.
0:10:03 > 0:10:06Over such rugged, icy terrain,
0:10:06 > 0:10:10aeroplanes are pretty much the only way to get around.
0:10:11 > 0:10:14It takes a cool head to navigate this kind of landscape.
0:10:17 > 0:10:21RADIO: "561 Tango Alpha's 10 north at 5,000 feet
0:10:21 > 0:10:22"heading into broad paths.
0:10:22 > 0:10:25"Weather's clear."
0:10:26 > 0:10:28There's an old bush pilots' saying,
0:10:28 > 0:10:32"You can fly for an hour, or you can walk for a week."
0:10:34 > 0:10:37RADIO: "Pressure's steady, ten miles of visibility."
0:10:38 > 0:10:42This is some of the last true wilderness on the planet.
0:10:42 > 0:10:46And the further north you go, the colder and emptier it gets.
0:10:54 > 0:10:57One family here can't wait for winter to really arrive.
0:10:59 > 0:11:02These polar bears need the sea to freeze completely
0:11:02 > 0:11:05so they have a solid platform from which to hunt seals.
0:11:09 > 0:11:10Right now, they're hungry.
0:11:16 > 0:11:19The cubs' mother can sniff out a meal from 20 miles away.
0:11:25 > 0:11:28The rotting remains of a bowhead whale.
0:11:29 > 0:11:31SQUAWKING
0:11:42 > 0:11:44It may not look too appetising,
0:11:44 > 0:11:47but this blubber is packed with calories and vitamins.
0:11:54 > 0:11:58An adult bear can eat 60 kilos at a single sitting.
0:12:10 > 0:12:12The problem with a feast like this
0:12:12 > 0:12:15is that it will bring in hungry bears from miles around.
0:12:45 > 0:12:46They might not be a threat,
0:12:46 > 0:12:49but she's not going to hang around to find out.
0:12:58 > 0:13:01SQUAWKING
0:13:14 > 0:13:16Soon the sea will be frozen solid
0:13:16 > 0:13:19and the bears will be back in their element.
0:13:28 > 0:13:32As the northern end of the Earth tilts further from the sun,
0:13:32 > 0:13:34the cold is now stealing across Alaska.
0:13:50 > 0:13:54These first strokes of winter give the land the look of a fairytale.
0:13:58 > 0:14:02As lakes freeze, the ice cracks and rattles.
0:14:04 > 0:14:07RUMBLING
0:14:10 > 0:14:13Tradition has it that this is the sound of the water
0:14:13 > 0:14:16crying for a blanket of snow to protect it from the cold.
0:14:26 > 0:14:28On rare days, when still, cold air
0:14:28 > 0:14:33lies on top of a freshly-frozen water, crystals grow,
0:14:33 > 0:14:34forming delicate fronds of ice.
0:14:39 > 0:14:41These are frost flowers.
0:14:41 > 0:14:44And they can bloom and fade in just a few minutes.
0:14:52 > 0:14:56By November, river ice can already be half a metre thick.
0:14:58 > 0:15:00But in true pioneering style,
0:15:00 > 0:15:03Alaskans turn this freeze-up to their advantage.
0:15:04 > 0:15:06Come by, come by.
0:15:10 > 0:15:13The frozen rivers and lakes become highways into the wilderness.
0:15:27 > 0:15:30These Alaskan huskies are built for the cold, and born to run.
0:15:33 > 0:15:36They make David Jonas' life just a little easier.
0:15:38 > 0:15:41The dogs, they expand my range.
0:15:42 > 0:15:44Going on foot is pretty arduous,
0:15:44 > 0:15:47but with the dogs, we can go 30 miles a day.
0:15:55 > 0:15:59For eight years, he's been living off the land in this lonely valley.
0:16:01 > 0:16:05It takes a hardy soul to survive winters like this,
0:16:05 > 0:16:07and even hardier dogs.
0:16:10 > 0:16:12I use the dogs for getting firewood,
0:16:12 > 0:16:17for hauling just about anything from the river up to the cabin.
0:16:17 > 0:16:20Water, fish for them, usually.
0:16:20 > 0:16:23You're my hardest-working dog!
0:16:23 > 0:16:25You want a fish tail?
0:16:28 > 0:16:30OK, guys, let's go.
0:16:34 > 0:16:38What makes huskies so special is their stamina.
0:16:38 > 0:16:43They have a unique metabolism that means they don't tire easily.
0:16:43 > 0:16:45They just keep going.
0:16:45 > 0:16:46By harnessing this power,
0:16:46 > 0:16:49the creeping cold can be kept at arm's length.
0:16:59 > 0:17:01They can burn through 10,000 calories a day.
0:17:01 > 0:17:04That's three times more than an average man.
0:17:08 > 0:17:11So it's extra portions of fish-head soup all round.
0:17:14 > 0:17:16There you go.
0:17:16 > 0:17:18A little breakfast.
0:17:24 > 0:17:26WIND HOWLS
0:17:29 > 0:17:33The Alaskan winter is creeping into every corner of the land.
0:17:38 > 0:17:41But in the Chilkat River in the far south,
0:17:41 > 0:17:43there's something almost magical happening.
0:17:48 > 0:17:52On this stretch, warmer water bubbles up from deep underground
0:17:52 > 0:17:55and keeps a few miles ice-free all winter long.
0:18:01 > 0:18:03There are salmon here.
0:18:04 > 0:18:08They've swum for 20 miles upriver to spawn in the open water.
0:18:14 > 0:18:16Bald eagles are waiting.
0:18:26 > 0:18:28It's the last great feast of the year.
0:18:33 > 0:18:35CHITTERING
0:18:38 > 0:18:42The native Tlingit people named this river Chilkat for a good reason.
0:18:42 > 0:18:45It means, "winter salmon storehouse."
0:18:48 > 0:18:52The fishing is very relaxed, while there's a lot to go around.
0:18:56 > 0:18:59But then winter really starts to ratchet up the pressure.
0:18:59 > 0:19:01WIND HOWLS
0:19:11 > 0:19:13Every day, more eagles arrive.
0:19:16 > 0:19:18CHITTERING
0:19:20 > 0:19:22The mood in the valley changes.
0:19:33 > 0:19:36SQUAWKING
0:19:36 > 0:19:38The Chilkat becomes the last-chance-saloon
0:19:38 > 0:19:40for eagles from across Alaska.
0:19:45 > 0:19:48Over 3,000 birds gather in the riverside trees.
0:19:54 > 0:19:58For a few weeks, it's the world's biggest gathering of eagles.
0:20:04 > 0:20:07One has a badly-deformed bill.
0:20:15 > 0:20:17She's not pretty...
0:20:20 > 0:20:22..but she's got some serious attitude.
0:20:35 > 0:20:37CHITTERING
0:20:53 > 0:20:56It comes down to who wants it most.
0:20:56 > 0:20:58CHITTERING
0:21:04 > 0:21:06SQUAWKING
0:21:17 > 0:21:20At minus 30, water freezes almost instantly.
0:21:24 > 0:21:27Suddenly, she's dragging around a girdle of ice.
0:21:37 > 0:21:40She may have flown a thousand miles to get to this river.
0:21:43 > 0:21:45She's not throwing in her hand that easily.
0:21:50 > 0:21:52SQUAWKING
0:22:05 > 0:22:08No-one got through an Alaskan winter by being feeble.
0:22:12 > 0:22:16And winter is going to get a lot worse before it gets any better.
0:22:19 > 0:22:21WIND HOWLS
0:22:25 > 0:22:29In the southern forests, the trees soften winter's blows.
0:22:35 > 0:22:39But there's little protection from the intensifying cold.
0:22:41 > 0:22:44A two-metre-tall moose.
0:22:44 > 0:22:46Everything about it looks awkward.
0:22:48 > 0:22:51That massive nose, those ears,
0:22:51 > 0:22:52that hump.
0:23:02 > 0:23:04But this huge deer is winter-proof.
0:23:06 > 0:23:09Those stilt-like legs keep its body just clear of the snow.
0:23:14 > 0:23:17And that long face means that the air it breathes in
0:23:17 > 0:23:20gets nicely warmed up before it hits the lungs.
0:23:24 > 0:23:28This giant is squeaking by on a diet of twigs and snow.
0:23:41 > 0:23:46If ever there was a symbol of Alaskan resilience, this is it.
0:24:05 > 0:24:10It's now getting so cold, the ground is frozen solid.
0:24:26 > 0:24:29The Arctic ground squirrel's core temperature has dropped
0:24:29 > 0:24:31to three degrees below freezing.
0:24:33 > 0:24:36His chilled body shows purple on this thermal image.
0:24:40 > 0:24:41WIND HOWLS
0:24:46 > 0:24:48As winter rages all across Alaska,
0:24:48 > 0:24:51ground squirrels are totally oblivious.
0:24:54 > 0:24:56FAINT BREATHING
0:25:03 > 0:25:06He's only alive because a tiny pilot light
0:25:06 > 0:25:09between his shoulders is just ticking over.
0:25:13 > 0:25:15Every two or three weeks,
0:25:15 > 0:25:18this thermostat kick-starts his internal heating back to life.
0:25:21 > 0:25:25He shivers, flooding his body with a life-saving pulse of warm blood,
0:25:25 > 0:25:28which briefly reboots and repairs his brain.
0:25:39 > 0:25:42After a few hours, the heating switches off again
0:25:42 > 0:25:45and his body temperature drops back towards freezing.
0:25:49 > 0:25:52An Arctic ground squirrel is only conscious
0:25:52 > 0:25:55for about 12 days during the whole winter.
0:26:01 > 0:26:02WIND HOWLS
0:26:11 > 0:26:14Up in the far north, winter takes a different tack.
0:26:16 > 0:26:18It's cold enough to freeze the ocean.
0:26:21 > 0:26:24It all starts at two degrees below zero,
0:26:24 > 0:26:27when crystals of ice coalesce into a slushy mat.
0:26:32 > 0:26:34But the freeze-up can take weeks.
0:26:46 > 0:26:50Soon, the bears will be able to use the ice to hunt seals.
0:26:51 > 0:26:53WIND HOWLS
0:27:05 > 0:27:07As pancakes of ice lock together,
0:27:07 > 0:27:10the Arctic Ocean starts to transform.
0:27:14 > 0:27:16It's good news for the fox.
0:27:16 > 0:27:18He'll follow the bears like a shadow,
0:27:18 > 0:27:21ready to pick up any scraps whenever they make a kill.
0:27:28 > 0:27:31Until then, he'll amuse himself by teasing the cubs.
0:27:46 > 0:27:48New ice is unpredictable stuff.
0:27:50 > 0:27:54The youngsters seem perplexed by this strange surface.
0:28:03 > 0:28:05Sea ice is bendy
0:28:05 > 0:28:08and flexes beneath their feet because of the salt.
0:28:10 > 0:28:13At 300 kilograms, Mum knows the sensible thing
0:28:13 > 0:28:16is to spread the weight by walking like a cowboy.
0:28:22 > 0:28:23But you can't beat gravity.
0:28:34 > 0:28:36As the ice thickens,
0:28:36 > 0:28:39the cubs get a chance to practise their seal-hunting skills.
0:28:49 > 0:28:52They throw themselves at it with all the enthusiasm of youth,
0:28:52 > 0:28:55but it will be another year before they'll actually catch anything.
0:29:09 > 0:29:13The bears save their energy while the sea freezes around them.
0:29:23 > 0:29:25Things are moving fast.
0:29:25 > 0:29:29Another 20,000 square miles of Arctic Ocean
0:29:29 > 0:29:30turns to ice every day.
0:29:42 > 0:29:44Winter now starts to squeeze Alaska hard.
0:29:47 > 0:29:48And not just with the cold.
0:29:51 > 0:29:52In November, in the far north,
0:29:52 > 0:29:55the sun dips below the horizon
0:29:55 > 0:29:58and it won't rise again until January.
0:30:00 > 0:30:02That's 65 days of night.
0:30:06 > 0:30:08The last thing the polar bear family wants
0:30:08 > 0:30:11is to blunder into another bear in the darkness.
0:30:14 > 0:30:16There are big males out here
0:30:16 > 0:30:18that would easily kill one of the cubs.
0:30:23 > 0:30:25She won't leave them to fend for themselves
0:30:25 > 0:30:27until they're at least two years old.
0:30:39 > 0:30:44Further south, the darkness and the cold have less of a stranglehold.
0:30:44 > 0:30:46WAVES CRASH
0:30:51 > 0:30:53And if you're tough enough,
0:30:53 > 0:30:57the Bering Sea is a place to claw something back from winter's grasp.
0:31:03 > 0:31:07By midwinter, snow crabs gather in their millions
0:31:07 > 0:31:09200 meters down on the seabed.
0:31:15 > 0:31:19For Joshua Songstad, captain of the crabbing boat 'Handler'
0:31:19 > 0:31:20the stakes couldn't be higher.
0:31:20 > 0:31:22When did you set that strength?
0:31:22 > 0:31:24INDISTINCT RADIO
0:31:24 > 0:31:27'Once you've found that pot of crab,
0:31:27 > 0:31:29'you can just follow it to where it goes.
0:31:31 > 0:31:35'As long as you stay on top of it, your fishing can be phenomenal.
0:31:36 > 0:31:39'It's crazy how good it can be. These pots come up,
0:31:39 > 0:31:42'you couldn't stuff another crab in there sometimes.'
0:31:52 > 0:31:55Each crab pot weighs 300 kilos
0:31:55 > 0:31:57and they must be heaved from the sea
0:31:57 > 0:32:00and manhandled around the icy decks day and night.
0:32:26 > 0:32:28The cold, the heavy machinery and the storms
0:32:28 > 0:32:31all take their toll on the crew.
0:32:31 > 0:32:34WAVES CRASH
0:32:34 > 0:32:37Being a deckhand on an Alaskan crabbing boat
0:32:37 > 0:32:39is still one of the riskiest jobs in the world.
0:32:47 > 0:32:50But if they're lucky, the catch can be spectacular.
0:33:01 > 0:33:04My main function is to catch crab, keep that block turning,
0:33:04 > 0:33:06keep those pots coming and keep the crab coming down.
0:33:06 > 0:33:08There's no other reason to be here.
0:33:11 > 0:33:12As the deckhands say,
0:33:12 > 0:33:15"If the block's not turning, we're not earning."
0:33:18 > 0:33:22Once the hold is full of crab, the crew will head for home,
0:33:22 > 0:33:25hundreds of thousands of dollars richer.
0:33:29 > 0:33:31WAVES CRASH
0:33:35 > 0:33:38By December, the nights are at their longest.
0:33:39 > 0:33:41Even in the south, there are just
0:33:41 > 0:33:44a few hours of murky daylight every day.
0:33:48 > 0:33:50Anchorage.
0:33:54 > 0:33:58There are only 700,000 people living in Alaska,
0:33:58 > 0:34:00and almost half of them live here.
0:34:04 > 0:34:06And they have some unlikely neighbours.
0:34:09 > 0:34:11A moose has wandered out of the forests,
0:34:11 > 0:34:14looking for something tastier than twigs.
0:34:15 > 0:34:17MOOSE GRUNTS
0:34:17 > 0:34:19He's not the only one.
0:34:19 > 0:34:23By midwinter, 1,000 winter-weary moose have arrived,
0:34:23 > 0:34:25looking for some comfort.
0:34:32 > 0:34:34There are gardens here, and parks,
0:34:34 > 0:34:36all full of tasty goodies.
0:34:36 > 0:34:38BARKING
0:34:44 > 0:34:47And old, frozen pumpkins left over from Halloween.
0:35:00 > 0:35:03They may trample the garden and ruin the fairy lights
0:35:03 > 0:35:05but the residents are used to it.
0:35:12 > 0:35:17Even in town, these moose are on a near-starvation diet,
0:35:17 > 0:35:19losing half a kilo of body weight a day.
0:35:22 > 0:35:24And winter hasn't finished with any of them yet.
0:35:26 > 0:35:28MOOSE GRUNTS
0:35:33 > 0:35:37Even though the darkness starts to lift with the new year,
0:35:37 > 0:35:41the Alaskan winter is just about to whip up another storm.
0:35:48 > 0:35:50Nowhere does it deliver a harder punch
0:35:50 > 0:35:53than in the mountains of Alaska's southern coast.
0:35:55 > 0:35:58It's here cold air from the frozen interior
0:35:58 > 0:36:00meets moist air blowing up from the ocean.
0:36:08 > 0:36:11The fall-out from this atmospheric brawl is snow.
0:36:12 > 0:36:14Lots of snow.
0:36:14 > 0:36:19In some places, more than 20 metres can accumulate through the winter.
0:36:24 > 0:36:27If you're unlucky, the ferocious Alaskan winter
0:36:27 > 0:36:29will find you and knock you down.
0:36:33 > 0:36:36But one animal's fall can be a lifeline for others.
0:36:36 > 0:36:38SQUAWKING
0:36:39 > 0:36:41Ravens are first on the scene.
0:36:53 > 0:36:56The carcass is almost frozen solid.
0:36:56 > 0:37:00All they can do is chip off a few icy splinters of meat.
0:37:00 > 0:37:02SQUAWKING
0:37:05 > 0:37:09It's enough to keep them going until dark,
0:37:09 > 0:37:11but they know that tomorrow, they will feast.
0:37:17 > 0:37:19HOWLING
0:37:21 > 0:37:24In the bitter night, a thermal camera reveals a visitor.
0:37:26 > 0:37:27A wolf.
0:37:38 > 0:37:41She's powerful enough to break open the frozen carcass.
0:37:44 > 0:37:46And by ripping into the meat,
0:37:46 > 0:37:48she's doing everyone else a favour, too.
0:37:55 > 0:37:56BIRDSONG
0:38:02 > 0:38:04SQUAWKING
0:38:08 > 0:38:10The carcass is now totally torn open,
0:38:10 > 0:38:13and there's still plenty of meat to fight over.
0:38:13 > 0:38:15SQUAWKING
0:38:18 > 0:38:20If you're clever, you gorge yourself
0:38:20 > 0:38:23and then hide a few pieces of flesh in the freezer for later on.
0:38:26 > 0:38:28CHITTERING
0:38:30 > 0:38:32SQUAWKING
0:38:45 > 0:38:49The carcass is too valuable to give up without a fight.
0:38:55 > 0:38:57SQUAWKING
0:39:00 > 0:39:04The eagle is too hungry to have his feather's ruffled easily.
0:39:04 > 0:39:06SQUAWKING
0:39:14 > 0:39:17But even the eagle must give way to a coyote.
0:39:19 > 0:39:21SQUAWKING
0:39:31 > 0:39:33The chance of a free lunch
0:39:33 > 0:39:36is dragging all sorts of desperados out of the woods.
0:39:43 > 0:39:46A battle-scarred old lynx, blind in one eye.
0:39:54 > 0:39:57WIND WHISTLES
0:40:07 > 0:40:11Everyone is watching, waiting for any sign of weakness.
0:40:12 > 0:40:14SHRIEKING
0:40:23 > 0:40:26The coyote leaves with his tail between his legs.
0:40:29 > 0:40:33While out in the deeper snows, a little planning can go a long way.
0:40:39 > 0:40:41SQUAWKING
0:40:44 > 0:40:46There are far worse places than here to be hungry.
0:40:50 > 0:40:52WIND HOWLS
0:40:56 > 0:41:00The longest, bitterest winter of all is up on Alaska's Arctic coast.
0:41:12 > 0:41:16In February, the mercury is dropping to its very lowest.
0:41:19 > 0:41:21Perfect for polar bears.
0:41:32 > 0:41:35They're out on the sea ice, looking for seals.
0:41:37 > 0:41:39And they're not alone.
0:41:45 > 0:41:50Polar bears can roam across 100,000 square miles of frozen ocean.
0:41:54 > 0:41:57And Arctic foxes will follow them for days
0:41:57 > 0:42:00in the hope of some leftovers from a seal kill.
0:42:11 > 0:42:14But that only works if the bears you are tracking
0:42:14 > 0:42:16find something worth eating.
0:42:29 > 0:42:34A piece of old seal skin. That's not going to go very far.
0:42:39 > 0:42:43But there's one other place a fox find food.
0:42:44 > 0:42:46If it's desperate enough.
0:42:54 > 0:42:56To go there means risking everything.
0:43:04 > 0:43:06This is Deadhorse.
0:43:15 > 0:43:17HORN BLASTS
0:43:17 > 0:43:21250 miles north of the Arctic Circle...
0:43:23 > 0:43:27..and one of the coldest, remotest settlements on Earth.
0:43:32 > 0:43:36Deadhorse only exists because there are huge reserves of oil
0:43:36 > 0:43:39to be extracted from below the ice.
0:43:42 > 0:43:46It's not the most welcoming place for a tiny arctic fox.
0:43:58 > 0:44:01First, he has to get past the local heavies.
0:44:07 > 0:44:11Red foxes followed the oil workers here,
0:44:11 > 0:44:12and they've made themselves at home.
0:44:14 > 0:44:17Twice the size of the arctic fox, he's quite capable
0:44:17 > 0:44:19of killing any trespassers on his patch.
0:44:21 > 0:44:24But the little fox is hungry enough to take the risk.
0:44:28 > 0:44:32Everyone knows you shouldn't put bare flesh on freezing metal.
0:44:34 > 0:44:39But the fox has to use his tongue to thaw out the frozen scrap.
0:44:49 > 0:44:53It's the kind of place where you have to hold your nerve.
0:45:14 > 0:45:17The freezing temperatures don't stop the oil workers
0:45:17 > 0:45:18going about their business.
0:45:24 > 0:45:29Winter is a good time to get those awkward little jobs out of the way -
0:45:29 > 0:45:34like moving a 2,000-ton drilling rig to a new field.
0:45:50 > 0:45:53Probably best not to try and push your luck too far.
0:46:18 > 0:46:21Just when it seems that warmth will never return...
0:46:25 > 0:46:28..there's a sign in the heavens that things are about to improve.
0:46:39 > 0:46:41The aurora borealis.
0:46:46 > 0:46:51They flare each time a cascade of particles streaming out from the sun
0:46:51 > 0:46:53smashes into the Earth's atmosphere.
0:46:59 > 0:47:03The aurora puts on its greatest show in March,
0:47:03 > 0:47:05just as spring starts to return.
0:47:14 > 0:47:17Traditionally, it was believed that these lights were torches,
0:47:17 > 0:47:19carried by spirits,
0:47:19 > 0:47:23to guide the souls of the lost to a new land of warmth and plenty.
0:47:36 > 0:47:40The arctic ground squirrel's central heating has switched back on.
0:47:49 > 0:47:53He's pulling back from the brink one more time.
0:48:00 > 0:48:04After eight months asleep, he's slowly reenergising,
0:48:04 > 0:48:06preparing to face the world again.
0:48:12 > 0:48:18Polar bears are still wandering the sea ice, making the most of it
0:48:18 > 0:48:20before the spring sun melts it away.
0:48:26 > 0:48:28For all Alaska's hardy souls,
0:48:28 > 0:48:32winter's supreme test of endurance is nearly over.
0:48:40 > 0:48:44The growing strength of the sun has got winter on the run...
0:48:45 > 0:48:49..and brings with it the promise of better times.
0:49:05 > 0:49:09As the thaw begins, these tough and resourceful characters
0:49:09 > 0:49:13have overcome the worst that Alaska can throw at them.
0:49:16 > 0:49:20Now they can once again stake their claim on this land.
0:49:42 > 0:49:45Of all the challenges of an Alaskan winter,
0:49:45 > 0:49:49filming arctic foxes is one of the toughest.
0:49:49 > 0:49:52First, you have to get to the Arctic.
0:49:52 > 0:49:54Cameraman Toby Strong.
0:49:55 > 0:49:57This is the Dalton Highway.
0:49:57 > 0:50:00It runs 500 miles north, from Fairbanks
0:50:00 > 0:50:04right to the very top of the North American continent to Deadhorse.
0:50:04 > 0:50:07That's where we're going to try to film the arctic foxes.
0:50:07 > 0:50:10First, we have to get there along this road, which is
0:50:10 > 0:50:13one of the most dangerous on the planet, for this reason.
0:50:15 > 0:50:20It's ice the whole way. So, yeah, we have to get there first.
0:50:25 > 0:50:28The Dalton Highway was built to supply the oil industry
0:50:28 > 0:50:30on Alaska's north coast.
0:50:36 > 0:50:41Toby, director Tuppence Stone and field assistant Jonathan Fiely
0:50:41 > 0:50:43set off for the two-day journey.
0:50:45 > 0:50:47It's not one for a nervous driver.
0:50:51 > 0:50:55As well as the icy roads, there's also the danger of avalanches.
0:50:57 > 0:51:00Before they can cross the highest pass, the crew must wait for the
0:51:00 > 0:51:04highway department to clear any potential threat.
0:51:05 > 0:51:08BLAST
0:51:09 > 0:51:11Fire. Fire!
0:51:11 > 0:51:12BLAST
0:51:16 > 0:51:20- All clear.- Right, we have to film foxes, I guess.- Back onto foxes now.
0:51:23 > 0:51:27250 miles inside the Arctic Circle,
0:51:27 > 0:51:31Deadhorse really is at the end of the road.
0:51:38 > 0:51:41There's nothing between here and the North Pole
0:51:41 > 0:51:43except 1,200 miles of ice.
0:51:53 > 0:51:55So this is home for the next two weeks.
0:51:57 > 0:52:00Next morning, the cold has intensified.
0:52:02 > 0:52:03Ladies and gentlemen,
0:52:03 > 0:52:07This morning, the temperature is a balmy -47 degrees Fahrenheit.
0:52:09 > 0:52:12And at these temperatures, strange things happen.
0:52:12 > 0:52:15Here, we have one glass of boiling water. Watch this.
0:52:19 > 0:52:21Isn't that amazing?!
0:52:23 > 0:52:26Time to get the thermals on and go fox hunting.
0:52:30 > 0:52:32Deadhorse is surprisingly busy.
0:52:34 > 0:52:37It's the human presence here on the tundra that's the big
0:52:37 > 0:52:39attraction for the foxes.
0:52:39 > 0:52:44The foxes have already survived maybe six long months of winter,
0:52:44 > 0:52:48and the natural food source up here, which is lemmings,
0:52:48 > 0:52:49at this time of year is in a...
0:52:49 > 0:52:54It follows a cycle, and at the moment we're in a dip in that cycle.
0:52:54 > 0:52:57So foxes are clever, they will find whatever is around,
0:52:57 > 0:53:00and if that means coming into town and taking advantage
0:53:00 > 0:53:03of opportunities then that is why they are here.
0:53:03 > 0:53:06It's time to tap into the local knowledge.
0:53:09 > 0:53:11Hi, have you seen any foxes?
0:53:11 > 0:53:16- No.- We're trying to film the foxes. - I haven't seen them all winter.
0:53:16 > 0:53:20They're everywhere. You know, all of a sudden, they're there.
0:53:20 > 0:53:23- You're looking for the white ones? - Yeah.
0:53:23 > 0:53:25- Anywhere there's food.- Yeah.
0:53:25 > 0:53:27Ten years ago there would have been one walking in front of us
0:53:27 > 0:53:30- right now, they were everywhere. - Seriously?- Yeah.
0:53:30 > 0:53:32- Have a good day. - Thank you very much. Cheers.
0:53:34 > 0:53:36At least there's one consistent piece of advice -
0:53:36 > 0:53:40find out where the foxes are feeding.
0:53:40 > 0:53:42All these tracks are a good sign.
0:53:42 > 0:53:44Weird, isn't it?
0:53:44 > 0:53:49Arctic foxes, the sort of totem of the vast wildernesses
0:53:49 > 0:53:53of the North, and here we are, sat under a Portakabin.
0:53:53 > 0:53:55Not how I imagined...
0:53:56 > 0:53:59This cold is such a killer.
0:54:02 > 0:54:04It takes several days before the crew finds out
0:54:04 > 0:54:06who made the footprints.
0:54:07 > 0:54:10It's a fox...but it's the wrong colour.
0:54:15 > 0:54:18Red foxes are recent arrivals in Deadhorse.
0:54:20 > 0:54:23These pioneering foxes followed the human traffic
0:54:23 > 0:54:27up the Dalton Highway, and liked what they found.
0:54:28 > 0:54:32They scarcely give the crew a second glance.
0:54:36 > 0:54:39This confidence is a worrying development.
0:54:40 > 0:54:44We came here to film arctic foxes. So far, we've just seen red foxes.
0:54:44 > 0:54:47But, you know, we'll take what we can get at this point.
0:54:47 > 0:54:49What'cha gonna do?
0:54:50 > 0:54:54As the days pass, there seems to be red foxes lurking around every
0:54:54 > 0:54:57corner, but not a single white one.
0:55:02 > 0:55:07The bone-chilling cold and 18-hour days starts taking its toll.
0:55:08 > 0:55:13There's worrying signs of cabin fever amongst the team.
0:55:24 > 0:55:27Working day and night pushes everyone to breaking point.
0:55:43 > 0:55:45Just when they are ready to throw in the towel,
0:55:45 > 0:55:48the crew gets the call they've been waiting for.
0:55:48 > 0:55:50- RADIO:- 'We're just getting a message from the policeman
0:55:50 > 0:55:54'to say there's an arctic fox at the back, so we're going to go there.
0:55:54 > 0:55:55'Meet us there. Over.'
0:55:55 > 0:55:58'He's coming round the back, he's going under the building.'
0:55:58 > 0:56:01OK, we'll come in that side, park there and then see how he comes out.
0:56:01 > 0:56:02We'll get that side covered. Over.
0:56:09 > 0:56:10I have him.
0:56:10 > 0:56:14All he's interested in is finding something to eat.
0:56:14 > 0:56:17'Stay really calm. He's quite touchy.'
0:56:17 > 0:56:18OK, I've got him.
0:56:24 > 0:56:28'He is moving off behind the container. I'm going to go ahead.'
0:56:28 > 0:56:29The team can barely keep up.
0:56:33 > 0:56:35- You go that way.- Yeah!
0:56:35 > 0:56:37THEY PANT
0:56:37 > 0:56:41- Where is he?- He's climbed up on top of the containers here.- OK.
0:56:41 > 0:56:44He leads them on a merry dance through the town.
0:56:46 > 0:56:50'Move quickly, I'm going to go to the far side of the building.'
0:56:50 > 0:56:52It's hard to run with the heavy camera equipment,
0:56:52 > 0:56:55and the cold air is burning your lungs.
0:56:55 > 0:56:56Yeah, I'll be a minute.
0:56:58 > 0:56:59Oh, my God.
0:56:59 > 0:57:01SHE PANTS
0:57:02 > 0:57:05Oh, hold it there, hold it there, I see him now.
0:57:05 > 0:57:07But the fox is oblivious to the cold.
0:57:07 > 0:57:08I'll hang here.
0:57:08 > 0:57:10I think he'll move through.
0:57:18 > 0:57:21He should be getting some really nice stuff from there.
0:57:21 > 0:57:23'What the heck is that fox doing? Licking?'
0:57:33 > 0:57:36# Fox in the snow Where do you go
0:57:36 > 0:57:40# To find something you could eat?
0:57:40 > 0:57:45# Cos the word out on the street is you are starving... #
0:57:45 > 0:57:50This is an increasingly rare sight in Deadhorse, so the few hours
0:57:50 > 0:57:53spent in the company of such a tenacious little character
0:57:53 > 0:57:55are precious.
0:57:55 > 0:57:58# Fox in the snow... #
0:58:00 > 0:58:03We've been here two weeks, we haven't seen one arctic fox.
0:58:03 > 0:58:05The day before we leave,
0:58:05 > 0:58:08he allowed us to follow him for the last two hours.
0:58:08 > 0:58:12- We were looking at the depths of despair.- Absolutely knackered.
0:58:12 > 0:58:17Frozen, but so happy. Absolutely brilliant.
0:58:17 > 0:58:19THEY LAUGH
0:58:19 > 0:58:20The crew head for home...
0:58:22 > 0:58:26..leaving behind those tough enough to deal with the Alaskan winter.