♪♪ NARRATOR: These lofty peaks are among the most revered in history.

Their very name defines every mountain habitat the world over -- Alpine forest, Alpine lakes, Alpine tundra.

They are a battle ground of ice against rock, wind against water, winter against summer.

♪♪ And yet, remarkable mountaineers thrive here, busy with battles of their own... ♪♪ ...while others are slowly returning to reclaim their place.

♪♪ All must seize the high life of summer before these peaks become winter's fortress.

Soar into the Alps, a realm of white brightness... ♪♪ ...and thunder.

♪♪ ♪♪ ♪♪ NARRATOR: A thousand peaks crowning a continent -- The Alps.

Between sea and summits, a trove of natural treasures -- Alpine grasslands... Arctic tundra... Mediterranean gardens... gigantic glaciers... [ Squawking ] ...gaping canyons echoing the sound of thundering waters... ♪♪ ...dark woodlands full of mystery... [ Calling ] ...barren crags... and slopes of vivid green.

A raw expanse to overwhelm the eye of all but one -- the one who soars above it all.

♪♪ ♪♪ ♪♪ ♪♪ [ Eagle calling ] It takes an eagle's eye to appreciate the Alps -- their majesty and their dimensions.

[ Wind whistling ] ♪♪ ♪♪ From its rise over their eastern foothills until it lights up their western valleys, the sun takes nearly an hour.

Grim north faces forever steeped in frosty shadows, back to back with sunny southern slopes and valleys.

♪♪ This ice-clad barrier splits Europe into north and south, while its valleys have always been a bridge between east and west.

Arching across more than 600 miles and rising steadily from eastern lowlands westward to the highest peak, this crumple zone between converging plates sends major rivers to three different seas.

Surrounded by crowded land, the Alps are shared by eight nations.

Towards sunset, they do not end but dip down steeply into the depth of the Mediterranean Sea where they emerged.

From the coast below, a whiff of spring arrives... while some 6,500 feet higher up, the crests are arctic, and so is the wildlife.

[ Wind whistling ] ♪♪ ♪♪ An eagle's flight between these contrasts is just a matter of minutes.

♪♪ Erosion of the rising Alps turns coastal canyons into plains -- attractive human habitat.

♪♪ Steep slopes rising from these plains are terraced by thousands of stone walls.

♪♪ Ancient olive gardens are the haunt of Europe's biggest lizard.

[ Birds and insects chirping ] The ocellated lizard ranges from the western Mediterranean to the foothills of the French and Italian Alps.

[ Chirping continues ] Spring is the time for a male to visit a female's territory.

[ Water lapping in distance ] This is where she lives -- a self-dug hole, or one taken over from a rodent.

For a while, they move in together.

[ Chirping continues ] [ Lapping continues ] ♪♪ The sunny south-western fringes of the Alps are now resplendent with bright colors, alive with the rhythmic song of cicadas, fragrant with wild and cultivated herbs.

Lavender fields are vibrating with the hum of a zillion bees.

[ Bees buzzing ] ♪♪ A griffon vulture.

Plunging from 3,000 feet to nearly sea level, deep canyons like Verdon or Remuzat offer ideal nesting places for griffons.

[ Vulture screeches ] ♪♪ Cut out by cold mountain streams while inhaling warm ocean winds, these canyons invite Mediterranean vegetation and wildlife deep into the Alps.

It's a short cycle of rain clouds flowing inland from the nearby sea and these southern rivers rushing back towards the coast.

When the morning sun heats up the canyon walls, hundreds of master gliders launch into the thermals.

But in this season, every other adult stays grounded.

[ Flies buzzing ] For vultures, of course, the ground is vertical.

[ Vulture screeches ] Males and females take turns feeding their offspring in a lofty crib.

[ Buzzing continues ] The nestlings need lots of moisture, gathered from carrion.

Along these cliffs, the southern sun and hot up-winds make for a climate like in the Sahara.

♪♪ From this vertical desert, the birds soar into freezing spheres, covering hundreds of miles each day.

But for griffons, the peaks and glaciers are just fly-over country.

♪♪ ♪♪ Also just passing, a young golden eagle, a nomad searching for a space unoccupied by breeding pairs.

He's made it through a long winter.

Now morning temperatures are finally above freezing.

Remaining snow is wet and heavy now.

Up here, the sounds of spring are rather different from the birdsong and cicadas buzzing in the foothills below.

Each sunny afternoon, the rumble and roar of wet snow avalanches echoes from all sides like muffled thunder.

An avalanche's megaton momentum will thrust huge boulders across a valley floor and heap up mountains of compacted snow as hard as concrete.

Finding a safe and soft spot between ravines is crucial.

[ Marmots chittering ] After six months of hibernation deep in the ground, marmots need exercise.

Neighborhood scuffles offer a perfect opportunity.

Breaking the fast is also welcome, but the leftovers of last year's grazing are still a far cry from the fresh herbs that will soon sprout.

♪♪ Some like it wet.

[ Water dripping ] An amphibian way above 8,000 feet.

Sounds like a record.

Brown frogs have spent the winter in underground bodies of water.

On the very day the ice on high Alpine lakes begins to break, brown frogs appear as if summoned by a magic reveille.

Marmots are impatient to feed.

But not the frogs.

In their hundreds, they race towards the water.

None wants to miss the annual orgy.

In order not to freeze to death, the frogs must move in the daylight.

Their skins have a built-in sunscreen.

Ultraviolet radiation at this altitude is powerful.

♪♪ Just above freezing in here.

Quite agreeable.

♪♪ But in the shallows, over dark peat, the water is lukewarm, the perfect spot to spawn.

[ Frogs croaking ] The males ride piggy-back on the larger females, eager to fertilize the spawn as it's released into the water.

The orgy lasts three or four days.

Some males embrace their partners in autumn and cling to them all winter until this super-productive spring event.

High-mountain populations lay bigger eggs than those in the valleys, giving their offspring a boost for the short Alpine summer.

♪♪ ♪♪ Voraciously, a warm, dry wind licks the last snow from the slopes.

♪♪ Millions of crocuses have only been waiting for this moment.

♪♪ ♪♪ Alpine flowers now turn the meadows into an inverted star-spangled sky.

Neon colors and fluffy leaves shield many of these plants against aggressive radiation.

♪♪ Some visitors are not coming for the stunning scenery.

After a long winter of deprivation, roe deer are arriving from the mountain forest.

The females especially need fresh vitamins.

They'll soon give birth.

♪♪ The thawing ground is soaked now.

Deep down below the surface, cracks and cavities in the bedrock are filling up with water.

♪♪ Springs are gushing, streams are in spate.

♪♪ The mountains' green lungs are breathing again, exhaling the rich fragrance of life.

♪♪ From bursting buds and the bubbling of a thousand brooks, a strange percussion takes its cue.

[ Bird gurgles, pops ] [ Woodpecker hammering ] To capercaillie hens, this sound is music.

[ Hen screeching ] [ Hen gurgling ] [ Hen pops, screeches ] The artist is eager to impress the female audience.

[ Hammering continues ] Flashy iridescence, high jumps, and wildly flapping wings on a carefully chosen stage are sending a message -- Look at me!

[ Birds chirping ] [ Hen gurgling ] Enchanted, a female fan has dived down from the gallery right onto the stage floor.

She, too, has something to offer.

[ Hen gurgling, pops ] He's got what he wanted, but it's not the end of the show, which has turned on the neighbors.

[ Hen gurgling ] They want more than just to watch.

Lines are crossed.

[ Hen screeches ] This is his hen, on his very own claim.

To be enamored, embattled, and embroiled means to be blind to one's surroundings.

♪♪ This hunter, however, is anything but blind.

♪♪ [ Hen gurgles ] ♪♪ [ Hen gurgles ] Careful calculation is critical.

♪♪ With an eagle's wingspan, a rapid attack between the trees is risky.

[ Hen gurgles ] ♪♪ [ Woodpecker hammering ] [ Birds chirping ] [ Flies buzzing ] ♪♪ When a life is taken, it nurtures others.

This eagle was not hunting for himself.

♪♪ These nestlings are a few days old, two or three days apart.

From the moment of birth, they are competitors.

[ Chicks cheeping ] For about six weeks now, the female stays put while the male provides.

Later on, both parents will hunt.

[ Chicks cheeping ] [ Wind whistling ] For a nestling to become a fledgling, it takes about 12 weeks.

[ Cheeping continues ] In a brief mountain summer, a lot of growing has to be done.

While some lives start high up in dazzling sunlight, others begin way down in the dark.

♪♪ [ Woodpecker hammers ] ♪♪ [ Fox pups crying ] ♪♪ Within just a few weeks, a new generation is born in thousands of dens and nests across the Alps.

♪♪ [ Fox pups crying ] With a litter of five, suckling and warming the cubs, cleaning the den, and hunting will push parents to their limits.

[ Crying continues ] ♪♪ ♪♪ Vast tracts of the Alpine landscape are woodland.

The mix of broadleaf and conifers varies with altitude, orientation, and topography and harbors a wide variety of habitats.

A young boreal, or Tengmalm's owl, one of 10 different owl species in the Alps and a typical inhabitant of conifer forests.

Even fox parents will hunt in daylight now.

[ Birds chirping ] For these youngsters, everything is new, exciting.

♪♪ ♪♪ They are still too young to hunt, but they'll soon go for the sort of prey the fox has just missed.

♪♪ ♪♪ Fortunately there's no shortage of rodents in Alpine woods.

♪♪ Nor a shortage of enemies.

♪♪ A lynx will not tolerate foxes in its domain.

♪♪ The fox is lucky.

The lynx has something else in mind.

♪♪ ♪♪ European lynx, missing from the Alpine forests for a century, were reintroduced to various regions in the 1970s.

♪♪ Their preferred prey are roe deer, chamois, and young red deer, but also smaller game.

Lynx have a habit of hiding it from ravens, foxes, and other scavengers.

♪♪ ♪♪ ♪♪ Another home-comer from the woods of south-eastern Europe.

[ Insect buzzing ] This brown bear cub was born in the Alps.

Its mother would be an immigrant.

The two are poking around for insects, roots, and rodents.

A bear mother will shift aside rocks of 400 pounds with ease.

[ Buzzing continues ] Now and then, bears sniff out a real treasure.

Wild honeybees tend to hide their sweet gold in hollow trees.

[ Buzzing continues ] [ Bear groans ] This is a mouth-watering treat.

[ Bear growls ] No matter how viciously the angry bees attack, a bear won't be deterred from the taste of honey.

A few decades ago, there were only a handful of bears in the Alps.

Now, there are well over 100 individuals.

Some have wandered all across the Alps.

♪♪ ♪♪ 3,000 feet higher, the snow is gone.

Another 3,000 feet, and the snow still lingers in the shadows.

[ Bird screeches ] ♪♪ And up here, not just the snow is going.

♪♪ Animal Alpinists are shedding their winter wool.

♪♪ Not really a pretty sight.

♪♪ Just weeks ago, this cocky ptarmigan was still completely white.

For ibex bucks, getting rid of a mangy coat is an itchy affair.

[ Ptarmigan croaking ] The ptarmigan is also itching but in a different sense.

With some urgency, he's making himself heard, hoping to impress a hen.

[ Croaking continues ] ♪♪ This may not be the only use of horns, but it might explain their extraordinary length and their elegant curve.

♪♪ Horns, of course, are not just for scratching.

Bucks are busy all year-round testing their powers and prowess.

The swelling of the male's red eye bulges clearly signals his desire.

♪♪ Already one step ahead, a marmot is busy with parental tasks.

♪♪ The little ones are just over two weeks old.

Changing the hay is the marmot way of changing diapers.

A newly-born weighs as much as two tablespoons of salt.

To survive their first winter, they must increase their birth weight 40 fold within three months.

[ Marmots chittering ] ♪♪ Mountain hares have already replaced their snow-white winter coat with the camouflage of summer.

Right from birth, they are out in the open.

Unlike marmots, they are born with fluffy fur.

In cold weather, the mother keeps them warm.

♪♪ With the snow melt nearing its end, the roar and rage of spring's 10,000 torrents has faded, but glacial rivers are now running high.

♪♪ Swelling to a maximum under the midday sun and waning in the cool of night, glacial runoff carries megatons of finely-ground rock out into the lowlands.

♪♪ Europe's highest waterfalls and longest cataracts are the glaciers' spectacular gift.

♪♪ ♪♪ When glaciers vanish, rivers run dry, and valleys are filled with silence.

[ Wind howling ] As long as mighty rivers in the sky bring masses of moisture from the Atlantic and the Mediterranean, lush green mountain meadows above the tree line invite summer guests, as they have since the end of the last Ice Age.

♪♪ Red deer are back.

♪♪ After half a year down in the woods, red deer seem impatient to enjoy the sprawling pastures with their luxury of fresh herbs.

Stags shed their antlers after the rut.

To grow new ones just takes 3 1/2 months, from March to mid-July.

During the summer, the stags flock together in all-male groups.

♪♪ ♪♪ Calves and their mothers form their own herds.

♪♪ Among red deer, twins are a rare sight.

♪♪ ♪♪ Some ranges are not green at all.

Limestone karst formations are usually dry and rugged, uninviting, except for avid Alpinists.

♪♪ The grip and traction of these hooves are almost magical.

Total control of balance, sureness of foot, and no fear of heights are among the outstanding features Alpine ibex have developed in their giddying habitat.

It's lonely at the top, and that's exactly why ibex came to live up here.

Once humans had conquered the high Alps, ibex were nearly wiped out.

Today, they are back but face new challenges.

[ Ibex kid bleats ] Ibex are best adapted to the cold and suffer in hot weather.

At this time of year, mothers and kids like to play and rest on the last snow fields.

But now, instead of old snow, they often rest on dry scree.

♪♪ [ Ibex kid bleats ] 300 miles to the west and some 6,500 feet up, on granite, a similar scene.

♪♪ Grazing is sparse up here, but the world of the ibex is changing.

♪♪ ♪♪ The high Alps are getting greener, just like the Arctic.

Glaciers are losing ground which is soon colonized by hardy green pioneers.

♪♪ Carrying those heavy horns is tiring.

But after grazing, ruminants must rest in any case.

♪♪ Lately, however, even up here, the peace has been disturbed.

♪♪ Ever warmer summers bring horseflies and other parasites to an altitude where they had not ventured before.

♪♪ The animals are stressed.

[ Insects buzzing ] Many lose weight and get sick.

Worst of all, the new pests are affecting their reproduction rate.

[ Buzzing continues ] ♪♪ A warming climate means more than just stifling heat.

♪♪ While baking and drying out the slopes, the summer sun forces a glacial runoff.

♪♪ The net loss of ice each year is stunning.

As hanging glaciers disintegrate, huge volumes of ice and rock thunder down into the deep.

[ Ice cracking ] ♪♪ Once this ancient ice is gone, it's gone.

Debris-covered glaciers may last a little longer but also waste away from inside.

♪♪ On the last snowfields, mothers and aunts run an Alpine kindergarten.

[ Bleating ] Some of these aunts are gifted dance instructors.

♪♪ ♪♪ Delighted, the kids join in.

♪♪ ♪♪ ♪♪ [ Bleating ] ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ And now, refreshments!

♪♪ But, all of a sudden, the party is over.

♪♪ For a few weeks, chamois kids are just the perfect size for a hunting eagle, a welcome change from the eagle's staple food and easier to get.

♪♪ However, 8 out of 10 eagle kills are marmots, most of them youngsters.

[ Marmots chittering ] Even these heavyweights once had a risky childhood.

[ Marmots chittering ] When rough play gets too rough, mother has to interfere.

The eagle is always on her mind.

♪♪ [ Marmot chirps ] The old eagle's trick -- pretending to leave, letting the target relax.

[ Marmots chittering ] ♪♪ Then a surprise return... under the radar.

♪♪ ♪♪ [ Marmot chirps ] ♪♪ [ Marmot chirps ] Decelerating from 150 miles an hour... ...not even a cheetah would outrun an eagle.

♪♪ [ Marmots chittering ] ♪♪ They must have heard the mother panting and also that deadly swoosh of wings.

[ Marmots chittering ] How good to be alive.

[ Marmot chittering ] ♪♪ For the eagle mother, too, someone is waiting.

Of the two hatchlings of three months ago, one has survived.

It's time for takeoff.

♪♪ The mother goads him on.

Knowing that he's hungry, she's placed a carcass.

♪♪ [ Eagle squawking ] It must be the scariest and yet the most glorious moment in an eagle's life... and so satisfying to a mother.

♪♪ Leaving behind the limits of a single viewpoint, it's an explosion of perspectives.

♪♪ [ Eagle squawks ] ♪♪ That ravenous hunger is forgotten.

♪♪ Together, they soar.

During the year ahead, both parents will teach the young bird how to make it in this mountain wilderness.

♪♪ In this harsh environment, the bud of a glacier crowfoot takes two years to blossom.

Now the flowers are gone within minutes.

Both the snow vole and this hardy plant are Ice Age relics and champions of altitude.

No other Alpine mammal covers a range from 1,000 up to 14,000 feet.

[ Snow voles chittering ] Down under the scree, snow voles may seem like miniature marmots.

But in spite of living under even harsher conditions up here, they do not hibernate but spend the best part of the year in a labyrinth of tunnels under snow and ice.

[ Snow voles chittering ] ♪♪ ♪♪ ♪♪ Everything flows -- the light, the ice, even the rocks.

♪♪ Glaciers are gigantic conveyor belts moving enormous volumes of rock.

♪♪ This is the longest valley glacier in the Alps, the famous Aletsch.

In 2020, it's still more than 12 miles long and more than half a mile thick.

[ Ice cracking ] Due to a warming climate, nearly all the glaciers of the Alps are shrinking.

By the end of this century, not much will be left of the Aletsch glacier.

♪♪ Meltwater from the surface seeps deep into the ice, transporting heat into the glacier's core.

When a glacier shrinks, sooner or later, accumulations of boulders, scree, and sand dropped by the ice floe are conquered by the hardiest of trees.

♪♪ Prominent among these pioneers -- the stone pine.

How does it get up here?

[ Bird chirping ] The rasping calls of a special bird echo along the timberline, where stone pines define the scenery.

[ Bird squawking ] The spotted nutcracker and the stone pine have a win-win deal.

Stone pine seeds are too heavy to be spread by the wind.

This is where the nutcracker comes in.

Harvesting stone pine seeds is less a matter of strength than skill.

[ Bird squawking ] Begging from a parent is easier.

[ Squawking continues ] An adult flying off, his crop bursting with pine nuts.

Making sure that no one's watching, he buries his load, dozens of seeds in a single cache, adding up to 16,000 per season.

♪♪ These larders will get the bird through the winter.

Next spring, leftover seeds will sprout.

♪♪ In the high Alps, there are really just two seasons, one short and warm, the other long and cold.

[ Wind whistling ] When cold air from the Arctic flows south, the sky changes.

And not just the sky.

[ Whistling continues ] Frosty nights paint the green slopes red, brown, and yellow.

The colder the air, the warmer the hues, and the hotter the rut of the red deer.

[ Deer groaning ] Commotion, aggression, jealousy, unbridled lust, rough roars, and pungent perfumes make up a rutting ground.

[ Deer grunting ] Each mature, strong stag has staked a claim for his harem.

Once females have made their choice, they group around their stag... [ Deer bellows ] ...while rivals close in from every side.

Their females are synchronized, ready to conceive for just a few hours at a time.

[ Deer bellows ] Experienced stags will recognize this time window.

Pushy young rivals don't.

[ Deer grunting ] Relentlessly, they try to steal hinds from stags of high status.

The females run from these invaders while a boss struggles to stave them off and round up his harem.

♪♪ These constant scuffles are grueling.

♪♪ A neighbor attempts a hasty copulation.

♪♪ He fiddles and fails and enrages the boss.

♪♪ ♪♪ ♪♪ [ Deer bellows ] The challenger has lost the fight, but he can force a straying female back into his fold.

[ Deer bellows ] The calving season in spring will show whether their all-out efforts have been fruitful.

♪♪ The warm half of the year is over.

♪♪ Up on the highest peaks, winter has never really ended.

For the eagle and all the wildlife, harsh days lie ahead but also the stunning glory of winter in the Alps.

♪♪ It takes an eagle's eye and wings to pan out across the full range and richness, the gamut of life and landscapes encompassed by the Alps.

♪♪ ♪♪ "Nature's" journey into the Alps continues.

Here, there are two seasons, one short and warm, the other long and cold.

But the face of the Alps is changing.

Snowmelt threatens what used to be called the Eternal Ice.

For Alpine inhabitants, harsh days lie ahead but also the stunning glory of winter.

♪♪ ♪♪ ♪♪ ♪♪ To learn more about what you've seen on this "Nature" program, visit pbs.org.

♪♪