Narrator: At the extremes, Scandinavia gives way to a kingdom of ice... [Grunting] ♪ where the long, dark polar night melts into a sleepless rush of life under the midnight sun... [Birds squawking] transforming the landscape... [Grunting] and its creatures... beyond recognition.

To survive here, animals must navigate the most dramatic seasonal shifts on Earth, driven by the power of the sun.

Scandinavia is a land steeped in myth, the realm of Thor and Odin.

From Norway's frozen wilderness.. [Snorts] deep into magical Swedish forests... [Purring] across Denmark's windswept shores, to explosive Icelandic volcanoes.

♪ These breathtaking landscapes... ♪ have shaped its people... ♪ and its wildlife.

Bound together by a resilient spirit, they each face unique challenges in wild Scandinavia.

[Wind blowing] [Wind blowing] ♪ Scandinavia's far north is in the grip of winter.

♪ Lonely mountains and isolated Arctic islands are locked under the weight of snow and ice.

These are Scandinavia's most remote places.

Starved of sunlight in winter and plunged into the bitter cold, often reaching lows of -4 degrees Fahrenheit.

There are not many creatures who can bear this long, dark season, but for those who stay, this is a final stronghold in a warming world.

♪ ♪ Winds over 100 miles an hour greet the musk oxen of Norway's remote mountains.

♪ They are a relic of the ice age, unchanged for over 600,000 years.

Layers of thick fur shield them from the vicious weather.

♪ Herding together, they're at home in the long winter... but even in the gloom, the sun does not let the north forget her.

♪ [Rumbling] 93 million miles away, a solar storm is raging.

[Explosions] Electrically charged particles burst from the sun's surface... and hurtle towards Earth.

[Whoosh] As they reach our planet, the attack is deflected towards the poles by Earth's magnetic field, but some particles break through to the atmosphere and react with gases in the sky, igniting the lights of the aurora borealis.

♪ Only in the darkness can they be seen in their full glory.

Icelanders call them Nordurljós, the Dawn of the North.

They are a reminder that the sun will soon return.

On the western edge of Scandinavia lies the island of Iceland.

Only a few miles below the Arctic Circle, the Hornstrandir Peninsula spills out towards the north... in a series of dramatic fjords... and vast tracts of tundra.

In February, the late winter heaves thick sheets of snow and ice downhill towards the sea.

Small patches of berries from last autumn are uncovered in the weak sunlight... ♪ a morsel for Iceland's only native mammal, the arctic fox.

Her fur is thick enough to tolerate temperatures as low as -49 degrees... but it's not the cold that she needs to worry about.

Prey is scarce in the winter months, and a few berries are not enough.

It pays to keep an eye on the tides.

[Bird squawking] [Waves rolling] To survive here, arctic foxes must scavenge on the shoreline... but on the edge of Iceland, foraging is not always easy.

Every day that the sun grows stronger, the cliffs of snow edge towards collapse.

A formidable descent lies between her and her only hope of survival.

She can't afford to miss low tide.

There is no choice but to go down.

Hornstrandir's coast is revealed for just a few hours, and ravens have already arrived.

♪ [Squawks] She works quickly, trying to find something they might have overlooked before the tide cuts her off.

♪ Every inch of the beach is explored.

♪ ♪ This time, the strong currents have provided what she needs.

A sea urchin is a lifeline.

♪ In summer, these cliffs will come alive with nesting birds, and her resilience will be rewarded.

As the Earth shifts, the sun grows stronger.

For an arctic fox, the change can't come soon enough.

♪ In Iceland's Highlands, the lengthening daylight does little to thaw the hills.

In March, this is still winter's kingdom.

Each year, this is the first place to greet the cold and the last to say good-bye... but it's not as deserted as it seems.

♪ Bryn, Thorey, and Birna are no strangers to the cold.

These 3 friends take on a winter expedition ever year.

Bryn: I really love bad weather.

There's something healing in it.

It's just you against the elements.

It's--it's great.

Narrator: Crossing hundreds of miles over a single weekend, they set aside any fears to navigate over hidden rivers, across buried crevasses, and creep beneath heavy banks of snow.

In exchange, they are liberated from the daily grind.

Birna: For me as a woman, allowing me to have interests, to have something else than just being a mother, than just being a good employer.

I wanted just to put more adventure into my life.

♪ ♪ Narrator: On these trips, they are self-reliant, carrying everything they need and hours away from rescue.

Bryn: I like navigating, and that's my-- my strong suit is navigation and, um, reading maps.

Slowly, slowly you build up the experience, and you get more confident.

Narrator: But survival isn't just about mastering the conditions.

Thorey: The feeling of freedom.

I think freedom is the--like, the strongest feeling I feel when I'm traveling like this.

Narrator: With daylight fading, they're intended destination comes into view, Iceland's hot springs.

No trip to the Highlands should be without a restorative dip.

Bryn: The hot springs are a treat all year-round, but especially so in the wintertime.

[Speaking Icelandic] You find the hot spring and just soak it in and warm up.

♪ Narrator: There are geothermal hot springs all over Iceland.

The waters here are 100 degrees Fahrenheit and rich in minerals thought to have healing properties.

Birna: You are a bit tired after the challenge of taking on during the day, and it is the most amazing feeling.

Narrator: These hot springs are known in Icelandic as Landmannalaugar, the People's Pools.

For centuries, they have been used as a rest spot for weary travelers.

Little has changed.

♪ These hot springs are an oasis in a desert of snow, but humans aren't the only ones here soaking up the warmth.

Hidden amongst the mosses, a surprising creatures stalks the undergrowth-- laugakonguló, Iceland's pool spider.

Only the size of a thumbnail, these spiders are amongst the smallest of the wolf spider family.

They're found all over the world.

Normally dormant in the winter, here, they live a very different life.

The constant heat allows these spiders to defy the seasonal clock, thriving even in the middle of winter... ♪ but there are limits even here.

Wolf spiders must walk a perilous line between the worlds of ice and fire.

♪ One wrong step means being boiled alive... or swept away in the current.

Not everyone lives to see the summer... but stray too far from the hot springs, and a much colder death awaits.

[Flies buzzing] Luckily, their prey is also marooned.

These flies are hot spring specialists, feeding on nutrient-rich algae.

[Buzz] ♪ Wolf spiders earned their name from their predatory hunting technique.

[Slurping] ♪ It's sometimes hard to see the association.

[Buzzing] ♪ [Buzz] ♪ [Buzz] ♪ [Squish] Even the most hopeless spider gets lucky sometimes.

They might not be agile hunters, but in this warm oasis, they have the luxury of time.

♪ The hot springs across Iceland are a sanctuary from winter... but the volcanic forces that have created them... are as powerful as they are unpredictable.

[Rumbling] Since the history books began, Iceland has been a land dominated by ice and fire.

[Fwoosh] [Bubbling] Though they co-exist, it's fire that reigns here.

[Splashing] Iceland has over 100 volcanoes.

Magma is the lifeblood of this island... ♪ able to thaw Iceland's coldest winters and unleash ash clouds that turn day into night.

More explosive eruptions of the past might be behind the words of ancient poetry.

"Sól tér sortna"-- "The sun turns black."

"Leikr hár hiti"-- "Flames fly high"... "vio himin sjálfan"-- "as if against heaven itself."

♪ Nowhere else in Scandinavia can the Earth defy winter with such success... [Rumbling] but warmth is a distant memory in the far north.

At Scandinavia's extremes, the frozen islands of Svalbard lie deep inside the Arctic Circle.

♪ Here, the brutal winter has been one long night, but by March, the sun finally returns.

♪ In just one month, the daylight swings from 1 hour to 12.

Spring has finally begun.

[Polar bear grunts] [Wind blowing] The sun's reappearance ignites a dormant lust in male polar bears.

This male is now entirely devoted to finding a mate.

He might have to travel hundreds of miles to find a female... and in the vast frozen landscape, there's only one way to track down romance.

He must follow his nose.

[Snorting] Scent glands on polar bears' feet mean that every footstep they leave encodes their identity onto the ice... [Growls] and he's following the faint footsteps of a female.

[Grunting] [Sniffing] After days of pursuing her... there she is.

♪ Finding her is only half the challenge.

[Groans] Polar bear courtship is anything but simple.

Males are usually so aggressive that females spend most of the year avoiding them.

If he wants to win her trust, he'll need to turn on the charm.

[Growling] Because it takes so long for a polar bear couple to meet, her ovulation will only be triggered after several days of his company... ♪ and it'll take much longer than that for his efforts to bear any fruit.

After a winter alone, he's willing to take on the challenge.

South of Svalbard across the freezing Barents Sea, the northern tip of Norway is a patchwork of tundra and snow.

In mid-May, sunset merges into sunrise for the first time in the year.

The sun won't set again for another 8 weeks.

[Birds chirping] It's the beginning of a transformation in the arctic landscape and its animals.

Stunted willows provide the first nectar of the season... [Buzzing] [Birds chirping] and a song post for migrant birds from the south... but the tundra's most extravagant visitors have just arrived.

Male ruffs desperate for attention.

♪ This is a lekking ground.

Here, males defend their own tiny patch of tundra, performing elaborate dances to seduce their female audience.

♪ With 24 hours of sunlight, this performance goes on through the night.

Whenever boundaries are crossed, fights break out... [Chirping] ♪ [Chirping] but there are some who don't play by these rules.

Ruffs with white feathers are genetically different.

They will never hold a dancing patch of their own.

They're less aggressive than the other males, and perhaps that's why... the dominant dancers tolerate their presence.

They even coordinate dance moves for a more dazzling display.

[Rustling] But white ruffs have their own mating strategy.

He'll endure the leading male's ego if it means he can get a little closer to the ladies, but too close... [Squawk] and he's quickly put back in his place.

He'll need to be a little sneakier.

Perhaps he can trick this orange-maned male... ♪ but he's not the easiest dancing partner either.

[Chirping] An intruder interrupts.

This is his moment.

[Chirping] The white ruff steals the show... and there's nothing his competition can do about it.

[Chirping] He'll take every chance he can get, and with endless daylight on his side, he has plenty of time to push his luck.

[Chirps] ♪ Throughout June across Scandinavia, as each day grows warmer, the landscape becomes almost unrecognizable.

♪ The muted white of Iceland's Highlands gives way to a kaleidoscope of color.

♪ Meltwater braids across black volcanic sands.

♪ Flowers rush from seed to bloom in a race against time.

♪ In the ancient Norse calendar, these weeks of light were known as Sólmánuour, the Sun Month.

♪ [Low rumbling] Even in Svalbard, the stubborn remnants of winter are finally overthrown.

The sun is at the height of her power.

[Ice cracking] Temperatures climb up from their winter lows by over 40 degrees... [Water bubbling] and this world of snow and ice is unraveling at an unimaginable pace.

Every year, Svalbard loses almost 20 billion tons of water... and much of this water comes from glaciers.

In recent years, glaciers across Svalbard have been behaving strangely.

Scientists know that the Scandinavian Arctic, like most of the north, is undergoing a dramatic change.

♪ None more so than glaciologists like Dr. Heidi Sevestre.

Sevestre: My job is to study big monsters of ice like this guy behind me.

I find glaciers endlessly fascinating.

They are absolutely beautiful.

They are just mesmerizing.

♪ Narrator: Heidi has been studying glaciers for over 10 years.

[Crash] Ha ha ha!

Just another day at the office.

Narrator: Wahlenbergbreen is one of over 2,000 glaciers on Svalbard.

This is a river of ice 16 miles long emptying into the sea.

Sevestre: Glaciers in the Arctic are all being deeply affected by climate change.

The one we have behind us is quite a special one.

This glacier 5 or 6 years ago was almost completely static.

It was completely dormant, so slow.

Nothing was happening here, and simply, the glacier started to wake up and to accelerate.

[Rumbling] This is a glacier that is currently surging!

Narrator: As the Arctic heats up, Svalbard is experiencing more rain every year, which erodes through glaciers, making them slip faster towards warming seas in this process known as surging.

Heidi is here for the Arctic melt season to find out just how fast Wahlenbergbreen is moving.

Sevestre: Timelapse is truly a revolution in the field of glaciology, making the invisible visible.

Narrator: The team leave the timelapse cameras running over the summer to monitor the glacier's movements before retrieving the footage.

Sevestre: Using the timelapse footage and tracking some of the features in the ice, it tells us that the glacier is moving at about 4 to 5 meters per day, which is super, superfast for a glacier of this size.

Narrator: For scientists like Heidi, Svalbard is a glimpse into the future for places far beyond Scandinavia.

Sevestre: It is very important to have people to study what is happening here because it's showing us what will happen in the rest of the world in the decades to come.

Narrator: Because of climate change, the Arctic is warming twice as fast as the rest of the world, but Svalbard is warming even faster than that.

Sevestre: We've seen glaciers in Svalbard that, as the result of a surge, lost 80% of their entire mass.

Narrator: That is ice that the glacier will never recover.

Sevestre, voice-over: So what we are seeing here is-- is pretty much like a patient in intensive care, and all the alarm bells are ringing.

Narrator: Temperatures here are expected to warm by nearly 20 degrees by the end of this century, changing Svalbard beyond recognition... ♪ but Heidi believes there is still hope for the Arctic.

Sevestre, voice-over: What's very clear is that you can never stop an ocean that is rising.

We have all the cards in our hands today to fight the climate crisis, and that makes me incredibly hopeful for the future.

♪ Narrator: 20,000 years ago, great sheets of ice covered the whole of Scandinavia.

Ancient glaciers carved Norway's mountain valleys... but in the midday sun, the ice age is a distant memory... ♪ and the musk oxen of Norway were not built for this heat.

[Flies buzzing] [Breathing heavily] With two layers of thick fur, the leader of the herd is suffering.

[Ox grunts] His rank entitled him to this harem of females, all mothers to calves that he has fathered... [Ox grunts] but this mating privilege comes with responsibility.

He must protect and lead them until winter.

They can't stay in the hot, airless valleys.

Moving to higher ground brings relief, but it also means the musk oxen scattered across Dovrefjell, are slowly moving closer together... an unwelcome prospect for the male.

Late summer triggers the start of the musk ox rut.

His position of dominance must be defended in battle every year.

[Grunting] ♪ A rival male.

♪ This challenger knows he is an equal match.

[Grunts] Presenting his broadside demonstrates his bulk.

The defender won't tolerate such insolence.

♪ ♪ They charge at speeds over 30 miles per hour.

[Both grunting] ♪ Despite having a skull thicker than a brick and a brain smaller than a fist... these impacts cause lasting damage.

[Crack] [Both grunting] They're too evenly matched to end the fight quickly.

Instead, they try to throw their opponent off balance.

♪ ♪ The defending male times it right.

It's enough to finish it.

His legacy is protected... [Ox grunts] for now.

The musk ox rut will only end at the first signs of winter.

Under the glare of the sun, he'll be tested to his limits.

Other arctic animals seem to be reveling in life under the midnight sun.

[Birds squawking] In Svalbard, freed from sea ice, the shoreline provides summer visitors with round-the-clock feeding opportunities.

♪ [Birds squawking] ♪ In Hornsund, the Arctic's most numerous seabird is permanently dressed for dinner.

[Squawking] ♪ This warzone of rock is the seasonal home of the little auk.

Spending their life at sea, little auks come on land for just a few months of the year.

Concealed between the boulders lies a badly kept secret.

[Squawking continues] ♪ ♪ Over 55,000 little auk chicks hiding out of sight.

[Cheeping] They need to grow up quickly and fledge before the temperature drops below freezing.

They have just under 4 weeks.

Little auks mate for life, and his parents are a team, coordinating daily trips over 60 miles out to sea to ensure their chick is never without food for long.

Raising young like this is a massive energy investment, so each pair will only have one chick, one shot at parenting every year... but they are devoted to the cause.

[Chattering] Each day, the chick will eat half its body weight in energy-rich zooplankton.

When he is not being fed, he's alone in the nest... [Cheeping] but there is always someone watching.

Glaucous gulls.

They are ruthless predators.

[Gull crying] ♪ Suddenly, the nest made of rocks makes sense.

This is a fortress... and enemies are everywhere.

[Gulls crying] ♪ [Birds squawking] Little Auks do have one ally here.

Kasia Wojczulanis-Jakubas from the University of Gdansk in Poland has studied little auks for almost 20 years.

Wojczulanis-Jakubas: Part of me treats them as data points.

Part of me treat them like, I don't know, not even like pets but like family members.

Kasia's devotion keeps her coming back year after year to monitor the little auk chicks... [Birds squawking] and the health of their parents.

♪ With a bird in hand, Kasia can take its measurements.

It's pretty heavy.

163.5.

Narrator: But not all her results are so positive.

GPS trackers are revealing the adults are having to work extra hard.

Wojczulanis-Jakubas: Working here for almost 20 years, I can really say that this year is very, very different from the others.

Like, they started to breed very early, like the earliest ever, and then apparently struggle a lot to get food for the chicks, and it seems like they travel really, really far.

It's like 100 kilometers.

Ah.

Oh!

Ha ha ha!

Narrator: Kasia has discovered, as Svalbard's seas are warming, little auk parents are having to fly further than ever before to find food for their chicks.

60 miles per mouthful is a big ask for a tiny bird.

Wojczulanis-Jakubas: Little auk prefer Arctic zooplankton.

They are much more rich in energy compared to Atlantic zooplankton... but in recent years, there is more and more frequent warm Atlantic waters.

That makes these foraging conditions really harsh for the little auks.

So the little auks are kind of sentinels of the Arctic ecosystem.

You will always have better and worse seasons, but I think these worse seasons they happen to be more and more frequent, and this is very likely to be an effect of this climate change.

Narrator: The warming world adds to the challenges of growing up here, but as July gives way to August, at least for now, the sun's power in the north is beginning to wane.

The temperature on land drops, and fogs roll across the colony, announcing the end of summer.

It's a warning that time is running out.

At just two weeks old, this little auk chick must begin preparing for the flight of his life... but it's too cramped in here.

He'll have to go outside.

[Trumpeting] The gulls pick off unwary chicks as they emerge.

Despite the risks, he needs to exercise his wings before he can fledge.

[Cheeping] ♪ This practice is vital.

♪ The gulls ignite terror in the young chicks... [Cheeping] [Squawking] [Gulls crying] but they must continue their training.

Every fledgling chick has a guardian for their first flight.

It's a nervous time for any parent.

♪ Once they take off, they will have to head straight to the open ocean.

There's no turning back.

A young female is also readying herself... ♪ and with some imperceptible signal... she's gone.

Not everyone can pluck up the courage so quickly.

Soon, pairs begin disappearing into the horizon.

♪ ♪ True freedom... and just in time.

[Squawking] ♪ By late August, Svalbard's slopes fall quiet once more.

The sun dips below the horizon for the first time in over a hundred days.

Seasonal visitors depart in their thousands, fleeing the coming winter.

♪ Many who remain welcome the return of the cold.

Solitary polar bears are once again free to roam the expanding sea ice.

Musk oxen regroup into larger herds to face the winter together.

Iceland's foxes wait for new treasures on the tides.

Over the next few weeks, the daily temperature drops from over 30 to just 14 degrees, and soon after, the sun finally surrenders to the polar night.

♪ To order Wild Scandinavia on DVD, Visit ShopPBS, or call 1-800-PLAY-PBS This program is also available on Amazon Prime Video ♪