Summer Alaska: Earth's Frozen Kingdom

They call it America's last frontier.

Half a million square miles of wilderness.

This is Alaska.

Home to some of the hardiest animals on the planet.

LOUD CALLS

Alaskan seasons run fast and furious.

Opportunities are fleeting...

..for people as well as animals.

Survival means making the most of nature's gold rush.

Play it right...

and you'll hit the jackpot.

-Get it wrong...

-CHIRPING

-..and you could lose it all.

-SQUAWKING

TWEETING

It's not about your size.

It's about your attitude.

This land belongs to the bold.

GROWLING

-This is Alaska.

-ROARING

The rising warmth of the spring sun

has unlocked Alaska from the chill of winter.

The land has thawed and the rivers are flowing again.

It has become a land of promise.

SOFT WHINING

Now summer must deliver on that promise.

And it will have to be quick.

Alaska's summer days are crazy long,

but the season flies by.

Alaska is so big,

the seasons are staggered as they sweep up the state.

It's in the far south-eastern corner where summer first reappears.

Down here, wedged between the Pacific Ocean

and the southern coast mountains, there's an enormous rainforest.

This is Tongass, part of the biggest temperate rainforest in the world.

In May, just as summer arrives, so does a tough little visitor.

One that has made a 4,000-mile journey all the way from Mexico,

confident that Alaska will deliver.

SOFT TWEETS

A rufous hummingbird - the first sign of summer.

She only weighs 4g, not much more than a penny coin.

There are no other hummingbirds in Alaska,

so it's worth the endurance flight to get here.

There's less competition.

She's come here to feed on Alaska's summer flowers.

But she seems to have arrived too early.

With 60 wing flaps a second, she's burning up the calories fast.

She needs to refuel.

Acre for acre, this forest has more organic matter in it

than any other forest on Earth.

There's plenty of food round here,

if she's cunning enough to find it.

Every day, the sun is staying in the sky an extra ten minutes.

And as the days get longer, the opportunities get bigger.

At Katmai, along the southern coast,

speculators have been coming down from the mountains.

BIRDS CALL

GROWLING

Grizzly bears.

They sleep hard through the seven months of winter,

but their summers are intense.

SNARLING

ROARING AND GROWLING

Whilst the males work out who's boss,

this female is more interested in finding something to eat.

She's lost over a third of her body weight during winter,

and, right now, there's not much around except grass.

A pumped-up male could kill her cub.

GROWLING

But it's worth the risk to come here.

The bears of this coast are all here

because a feast is about to be delivered from the ocean.

GULLS CALL

Not that there's any sign of it yet.

There is something else to eat on the beach...

..but it will only be available when the tide goes out.

It's under their feet.

They can smell it.

SNIFFING

A clam.

It may not look like much,

but this seafood is rich.

And these six mile-long mud flats are full of them.

It's not as easy as it looks.

All the while, the clams are escaping downwards through the sand.

Sometimes, they move faster than a little bear can dig.

IT ROARS

A 130kg grizzly mum needs to find a couple of hundred clams a day,

to make it worth the effort.

But it all helps to keep them going

until the first real feast of summer arrives.

The forest takes its cues from the strengthening sunlight,

but it's still too early for the nectar-rich flowers.

The hummingbird must eat every 20 minutes

or run out of energy altogether.

But she's been coming to this forest every summer,

and she knows a few tricks.

TAPPING

A distinctive tapping noise signals just what she's been looking for.

A red-breasted sapsucker.

He's carefully chiselling holes in the tree-trunk,

so the tree's sweet syrup leaks out.

He'll be back later to feed, once the sap is flowing well.

It's the chance the hummingbird has been waiting for.

TAPPING CONTINUES

She just needs to get in unnoticed...

..while the sapsucker is busy at another tree.

It's all about timing.

The sugary sap is starting to overflow.

It's now or never.

Her tongue curls, grasping the sap,

licking it in at nine sips a second.

She can drink more than her body weight every day.

Over the next three weeks, she'll be back regularly to pilfer this store.

GULLS CALL

The Alaska summer is poised to release its bounty.

At Katmai, the grizzly bears are getting restless.

Their enterprising ways have kept them going,

but there are only so many clams you can eat.

They really need something more substantial.

It's not just the bears that are waiting.

Just off the south west coast, at Bristol Bay,

Alaska's fishermen are also gathering.

1,500 boats are here in anticipation

of the biggest fishing event of the summer.

The return of the salmon.

300 million salmon will swim towards Alaska's shores

over the summer months, and these fishermen are right in their path.

Alaska has the greatest runs of wild salmon in the world.

And Bristol Bay is the world's

most profitable salmon fishery of them all.

HORN BLOWS

Everyone fights to be in the hot spot.

In this bay alone, they catch 30 million salmon in one season.

The millions that escape the fishermen's nets

push onwards to the coast.

And, for the grizzly bears, the wait is finally over.

These fish are in prime condition...

..well fed and muscled from two years at sea.

The bears couldn't ask for a more bountiful feast.

They gorge themselves on 40kg a day.

It's a race to feed up.

Katmai has one of the densest grizzly bear populations

in the world, but there's still plenty to go round.

Mums bring their cubs to the places they remember from their own youth.

And where their own mothers first taught them to fish.

The fish are so plentiful,

they often won't even bother eating the whole thing.

They just chew off the fattiest parts -

the skin and the brain - and ignore the rest.

However, Mum's half always seems to look tastier.

GULLS CALL

Colossal runs of coho, sockeye, chum, pink and Chinook salmon

battle their way through shallows,

past bears and into the rivers beyond.

It's just the start of their journey.

Tens of millions of salmon migrate upstream.

On and on they swim, deep into the heart of Alaska,

following the scent of the river to find their way home.

Of all the salmon in the world,

the ones that travel furthest are the coho and Chinook

that migrate up the mighty Yukon River, 2,000 miles inland.

But 800 miles in, they hit another obstacle.

It's something you would only find in Alaska.

A fish wheel.

It belongs to Lester Erhart,

a native Alaskan, who has lived on the Yukon his entire life.

It's my home.

It's my home, right here.

I love it.

Lester spent the winter building the wheel by hand.

Now he's set it up in the river,

just in time for the return of the salmon.

BOAT ENGINE PURRS

Powered only by the current,

the wheel turns to the rhythm of the river.

As the salmon pass, they are scooped out of the water.

Three million Salmon travel up the Yukon during summer.

The wheel only works in a river this full of salmon.

All Lester has to do is collect the fish from the box.

It's brilliantly simple.

There was this young boy, about 14 years old,

and he came up and he looked in that box and saw all that fish.

He said to me, "You've got the right way to fish."

HE LAUGHS

This is the easy way to do things! HE LAUGHS

Lester can catch hundreds of fish a day.

Under the warm sun, the Alaskan summer has delivered a bonanza.

A third of Alaska sits above the Arctic Circle.

At the top of the world,

it's the last place to feel the warmth of summer.

But by June, this treeless land, the tundra,

is tipped towards the sun,

bathing it in 24-hour daylight.

At Alaska's most northerly point,

the sun rose at the beginning of May and won't set until August.

Summer in the Arctic becomes one endless day.

But you can have too much of a good thing.

It's now, in these odd conditions,

that a snowy owl is raising her family.

In the absence of any trees up here, she has to nest on the ground.

She has three growing chicks, and broods them 24 hours a day.

As she can't leave them, Dad will provide.

SQUAWKING

CHICK SQUEAKS

At first glance,

the tundra doesn't seem to be exactly brimming with food.

But it is, if you know where to look.

Lemmings.

They eat the grasses and shrubs that cover the landscape.

With the unlimited food here, they breed fast and, within a few weeks,

there can be millions of them,

exactly what Dad wants to see.

He just needs to choose his victim.

HIGH-PITCHED CALL

But one little lemming

is not going to go very far with his growing family.

These are North America's heaviest owls.

Each chick alone can eat three lemmings a day.

Hunting 24 hours a day, it doesn't take him long to satisfy everyone.

But it's as if the glut of lemmings has tripped his brain.

With no darkness to tell him when to rest, he just goes on and on.

The chicks are full to bursting...

..but still the lemmings keep on piling up.

Now his offerings aren't met with quite the same enthusiasm.

By the summer solstice, the sun's unblinking gaze is most intense.

Temperatures can climb over 30 degrees Celsius.

That's 80 degrees warmer than it was just three months earlier.

On the tundra, there's not a scrap of shade.

This female caribou left her herd eight weeks ago,

when she was due to calve.

It's easier to hide from predators when there are just two of you.

Her calf doubled in size in its first two weeks,

and now it's strong enough to join the herd.

It will spend the rest of its life on the move,

just one of 40,000.

SOFT GRUNTING

It's the middle of the night.

The caribou have reached the lake.

It's drawn in others from miles around.

It's not just a place to drink.

Buried in the mud at the bottom of the lake,

there are mineral salts, calcium, magnesium and sodium

vital for the caribous' health.

They stir up the mud with their feet and drink the solution.

Just beneath the surface of the water, an army is being mobilised.

The tundra offers the perfect growing conditions

for insect larvae.

Shallow pools, left over from melting ice,

warm up quickly in the summer sun.

Just eight days after hatching, they start to emerge as adults.

These are animals so well adapted

that they haven't changed in 40 million years.

BUZZING

Mosquitoes.

Literally trillions of them.

And hungry for blood.

BUZZING, GRUNTING

They are so big and ferocious,

the locals jokingly call them Alaska's state bird.

It is said they can form swarms thick enough

to asphyxiate a caribou.

Each animal can lose up to half a pint of blood a day.

It's enough to drive anyone mad.

BUZZING CONTINUES

The only defence they have is to move.

There will be no rest for this calf this summer.

He has just joined the longest land mammal migration in the world.

The herds are so big, they etch trails across the land.

All over Alaska, caribou are on an endless quest,

searching for fresh grazing...

BUZZING

..all the while being driven on by mosquitoes.

Alaska has more caribou than people.

Over 750,000 of them crisscross the state

covering thousands of miles in just a few months.

In the far north west, the caribou migration path

skirts round one of the most unexpected landscapes on the planet.

Here, 40 miles above the Arctic Circle,

there's a sun-scorched dune field.

At the height of summer,

temperatures here can reach 34 degrees Celsius.

It's about as hot as Alaska gets.

The annual rainfall here is less than the Grand Canyon.

The Kobuk Dunes are a footprint of the glaciers

that scraped across northern Alaska over hundreds of thousands of years.

As the glaciers retreated,

arctic winds picked up the grains of eroded sediment they'd left behind.

They whipped them up into dunes, some more than 30 metres high.

It's the largest active dune field in the whole United States.

But it's shrinking.

The vast banks of sand are slowly being infiltrated by trees.

Eventually, these ancient dunes will vanish

as the forests take them back.

These black spruce forests dominate interior Alaska.

They're desiccated by the heat and wind of summer and full of resin.

It doesn't take much to set the whole thing alight.

Every summer, around 500 major fires break out in Alaska's heart.

Left unchecked, wildfire can rip through 300 square miles a day.

There are very few roads across Alaska.

There's only one way to control a big fire in this vast wilderness -

from above.

It takes a crack team of firefighters to do this job.

They're drafted in from all across America

and specially trained for fighting fires Alaskan-style

because this plane isn't going to land.

Jumpers away.

Three, two, one, jump!

Jump!

These are Alaska's Smokejumpers.

All through the summer, they are the state's first line of defence.

A wildfire burns at 800 degrees Celsius

and can rage for weeks.

A Smokejumper's job is to stop the fire

before it gets too big to stop.

All right, ready for water. Turn that water back on.

Water coming to you.

RADIO: Just a quick update on the fire,

we'd like to call it contained.

It's hard to see a blaze like this as anything other than a disaster.

But Alaska's forests have been living with wildfire

for hundreds of thousands of years.

They've evolved not only to cope, but to benefit.

As long as black spruce cones are not totally torched,

the heat will open them up,

letting their seeds drop into a bed of fertile ash.

Sunlight brings a flush of new greenery to the forest floor.

These plant pioneers now have full access

to the endless summer sunshine.

Fireweed is the first to stake its claim.

It flowers through the hazy days

and Alaskans call it summer's timekeeper.

The flowers unfold from the bottom of the plant.

When they reach the top, that's the end of summer.

It's a warning that, despite the summer heat,

the first snows of winter are only weeks away.

High up in the Talkeetna Mountains,

there's one Alaskan who's already prepared.

The collared pika.

COLLARED PIKA SQUEAKS

He's spent his entire summer hard at work.

When the winter comes,

his favourite grasses and sedges will be buried under the snow.

But he's not worried.

He's been saving food for the lean months ahead.

COLLARED PIKA SQUEAKS

Hidden among the rocks is his winter larder.

He's carefully positioned it to catch the sun's rays,

which dry and cure his supply.

WIND HOWLS

Half a metre wide and 30cm deep,

this haystack is his survival rations.

He's chosen the contents meticulously.

He's picked some toxic plants,

these will decompose slower and keep food for eating fresher for longer.

COLLARED PIKA SQUEAKS

Like all Alaskans, he knows that winter preparations start early.

And you have to make the most of summer's bounty.

The sun is getting lower.

Summer is drawing to a close.

But rather than mourn its passing, Alaskans celebrate its generosity.

SCREAMS OF LAUGHTER

The Alaska State Fair

attracts more than a third of the entire population through its gates.

For 12 days from the end of August to Labor Day,

it's summer's final fling.

And the star attraction - the giant vegetable competition.

With 100 days of near endless sunlight,

you can grow record-breakers.

Cabbages heavier than a large child, supersized broccoli,

monster beans.

It's this high art of growing giants

that has kept Dale Marshall busy all summer long.

Well, we took our circumference, which was 190,

so then when you look on our chart here,

it tells you our estimated weight is 1,343lbs.

It could go heavier, it could go lighter,

but even if it goes a bit lighter, I've got a little buffer there.

So I'm hoping that we have a new state record here.

Dale has been harnessing the sun's power to nurture a giant.

A giant that's been growing 10kg a day

and has tendrils more than 20 metres long.

Dale has been growing a giant...

..pumpkin.

Don't really take any long vacations

or go out of state at all in the summertime here, you know.

So you try to make your travel plans,

you know, in the off pumpkin season so to speak.

Dale has spent three hours every day, all summer,

creating a monster.

As the plant get bigger, you've got to keep doing it more

cos there's more things to prune.

After a while it's just bleh!

It's big.

But to find out if it's a world-beater,

he needs to take it to the State Fair.

Just getting it there is a feat in itself.

Lifting a vegetable the weight of a small car

takes more than a wheelbarrow.

And we're done, we're separated!

We're ready to roll!

This is the most nerve-racking time for Dale.

You have to go up off the ground.

-Listen to it.

-Yeah.

-PUMPKIN CREAKS

Holy cow, look at it. Look at that thing strain now!

This pumpkin represents hundreds of hours of work

and thousands of hours of sunshine.

Damaging it would mean disqualification.

Oh, that looks beautiful!

Where do you want the vine going?

Touchdown!

-ANNOUNCER:

-'In the United States, we have a special award

'for the most beautiful orange pumpkin...'

At the fairground, everyone is gathering for the main event.

'..in a lot of the State Fairs. We wanted to make sure

'that beautiful orange pumpkin colour was recognised.

'Here we go!

'She said, "Put it on the scale!" Let's see where this goes.

-APPLAUSE AND CHEERING

-'All right, everybody, think heavy!

'Here we go.'

All right, come on!

Dale has come close before,

but he's never broken the State record.

That record stands at 1,287lbs.

1,283!

-Is that what that is?

-That's what it is.

1,283lbs!

Great effort!

4lbs off!

The sun has set on this year's competition.

But Dale doesn't waste time.

He collects the seeds and starts planning next year's pumpkin.

In Katmai, the grizzly bears are still catching fish.

A bear can eat a ton and a half of salmon over a good season.

It's what makes Alaskan bears the biggest in the world.

But the run is coming to an end.

By October, all these bears will head for the hills

and get ready to sleep out the winter.

Thanks to the wealth of fish,

they'll go into their dens 90kg heavier then they came out.

All across this super-sized state,

everyone has been cashing in on the abundance of summer.

Good grazing has allowed this bull moose

to grow something enormous of his own.

Something he hopes is going to get him noticed.

MOOSE GRUNTS

Two-meter-wide antlers.

At their peak, the bone was growing at 2cm a day.

They're the fastest growing organ in the natural world.

And during all this time, they have been completely...

useless.

Until now.

As the days get shorter and the sunlight weaker,

moose turn their mind to just one thing.

The annual rut.

MOOSE GRUNT

Young male upstarts test their strength against each other

with their puny headgear.

Hormones are raging.

For two weeks, they don't even stop to eat.

Each male is doing his best to stand out from the crowd.

But this big male is going to let his antlers do the talking.

And they're already causing quite a stir.

As a male moose gets older, his antlers get bigger and more ornate.

Now he's in his prime,

they're as big and as pointy as they're ever going to get.

No male will challenge him.

MOOSE GRUNTS

And he has the full attention of the female.

MOOSE GRUNT

While the young bucks carry on sparring,

he just has to do one simple thing.

He digs a pit and leaves his scent.

MOOSE URINATES

The pheromones released further advertise his machismo.

The whole package makes him irresistible.

MOOSE CONTINUES URINATING

In Alaska, they say that when it comes to finding a man,

the odds are good.

But the goods are often odd.

But with a headset this big, he's a keeper.

The sun's power has waned.

It's autumn.

Darkness steals another six minutes each day.

It's been a good summer for Lester.

His fishwheel has delivered him thousands of Coho salmon.

This will feed me in the winter and everybody else,

pretty near everybody.

Now he has to gut and fillet the fish.

He hangs it in the sun to dry and cure...

..and then he takes it into his home-built smokehouse.

The art of preserving fish has been in Alaska for thousands of years.

It's been passed down the generations

and it has allowed Alaskans to carry the bounty of summer

into the scarcity of winter.

It's knowledge that reached Lester as a boy.

It's helped him feed his family for 60 years.

He's in no hurry to change his ways.

I tried the other life and...

I like this life better.

In a few weeks, the mighty Yukon,

the river that brought the salmon to Lester's door,

will be frozen solid.

Temperatures will drop to minus 50.

But Lester isn't worried.

There are advantages.

I like winter.

Cos I don't have to work so hard! HE LAUGHS

All across Alaska, summer has delivered on its promise.

Under the gaze of the sun, there's been plenty for everyone.

Some have had to work harder than others.

But most have managed to get their piece of the pie.

Now time has run out.

They say you're not a true Alaskan until you've faced a winter.

It's time for the bold to step forward.

Of all Alaska's animals,

there was one that truly gave the film crew the run-around.

Caribou.

There are more than three quarters of a million of them,

so they shouldn't be that hard to find.

Filming them from the air is fairly easy.

But keeping up with them on the ground while they're migrating

is another matter.

They can travel 50 miles in a single day.

And this is rugged land.

Cameraman Rob Drewett and producer Alex Lanchester

were going to need some local knowledge

if they were to stand any chance of tracking them down.

Guide Dan Lee has spent most of his life in these hills

looking for gold.

He knows the wilderness pretty well.

-See how round that is? Look at that.

-Yeah.

Real obvious caribou - big difference from moose.

The team know they're in the right area.

They're already spotting caribou.

-(Where are they?)

-(They're just right over the edge.)

(We've just peeked over, there are ten or 15 just sitting there.

(So good to see them.)

But this is Alaska.

You can never be sure what's going to turn up.

And we've got a grizzly.

-It's grubbing for roots up there.

-Yeah, looks like it.

It's quite weird me filming caribou which are that way

and a grizzly bear that's just over my shoulder.

Hope someone's keeping an eye on it.

-Alex.

-Er...

-THEY LAUGH

With a grizzly bear in the area, the caribou aren't hanging around.

They're probably going that way, but we could go back around the trail.

If they're going over the ridge, we could meet them,

-cos there's another trail that goes that way.

-OK.

The caribou can go wherever they please.

The team have to stick to the trails.

It's starting to get challenging.

We've just had 200-300 standing right here.

And we were over there.

And it took us ten minutes to get here and suddenly they're gone.

-You see them all on that ridge over there?

-Yeah.

It's a cat-and-mouse situation.

The caribou certainly aren't going to wait.

The team need to get ahead of them.

But even an all-terrain vehicle has its limitations round here.

Are your wheels straight? You are right on a mud bank.

I've gone and got us stuck in the mud right at the edge of the river

and we are proper stuck.

Where are you going, Alex?

As the team try to free the vehicles,

the caribou get further and further away.

For them, a river crossing like this would be no trouble at all.

Thank you!

For the team, it gets worse.

Aw!

So we finally got our ATV out of the river

and we got out and there's a flat tyre.

And the spare doesn't fit.

-Wrong pattern, huh?

-No, the pattern's fine.

-The bolts are too big for it.

-Oh, no!

-See?

-Yeah!

In Alaska, road assistance comes from the sky.

I can't quite believe it's come to this.

Thank you very much, Mike. You've saved our bacon, so thank you.

OK, no problem, but we're going to get out of here before it changes.

-Yeah, of course.

-Have fun!

-Thank you.

It doesn't take long to change the wheel.

But bad weather is coming in.

The team decide to set up camp.

And all the while, the distance between the team and the caribou

is growing bigger and bigger.

The following day, the weather isn't any brighter.

Rained quite a bit last night.

So it's a little disconcerting.

24 hours of summer rain have made the rivers into torrents.

With all the rain we've had,

the river is way too high for us to cross.

It could be two to three days until we can cross it.

And then we don't know whether the herd's going to still be there

because they'll still be moving.

Another day lost and the caribou would've put 50 miles

between themselves and the team.

Caribou have no body clock telling them when to stop,

so keep walking through the night.

But the team have a tip-off from another guide.

They drive 100 miles east, putting their faith in guide Claude Bondy.

He knows of an unusual lake

where he thinks the caribou will gather in big numbers.

It could be the crew's lucky break.

But getting there means a four-hour hike across a boggy landscape.

It would be an easy journey for a caribou,

with its great feet and long legs, but much harder for the team.

In fact, we have to zigzag our way through,

cos we've got just brush in front of us.

Doesn't make things easy.

ALEX BREATHES HEAVILY

But Claude's hunch has paid off.

He knew the caribou would stop at this lake.

They're not just here for water,

they're here for precious minerals buried in the lake bed.

I didn't think it was going to happen, so...

It's nice to see such a big group

and we're talking thousands, so, amazing.

Just need to get a little bit closer.

(Whilst we've been sitting here,

(we've been completely surrounded by caribou.

(And they came about 30 metres away, which was pretty cool.)

Even the guide is astonished.

(This is the most caribou I've ever seen at one time.

(It's incredible.

(And they're all just kind of cruising right to Rob,

(he's got to be just going crazy right now.)

This close to the herd,

the team are not only able to film the big numbers,

but also capture behaviour not seen before,

as the caribou stir up the mineral salts in the water

and drink the solution.

We've had so many problems along the way with rain,

not seeing caribou, then being too far away.

So finally got the shots we needed, so it feels really good.

Next time...

winter has returned.

Those that cannot face it must leave.

For those that stay, the rewards can be huge.

But they must overcome minus 50 degree temperatures

to become masters of an ice world.

For many, it's courage that gets them through.

But for a few Alaskans, this is the time they have been waiting for.