Original subtitles

Meet nature's bulldozers.

(music)

an incredible force that's carved the planet

and challenged its wildlife for thousands of years.

(music)

but america's glaciers are on the run.

(music)

creatures must sink or swim in their wake.

(music)

(growling)

now, witness an extreme transformation of winter

into an ever-warming spring...

(squeaks)

(music)

...In a place where even mountains seem to melt.

(music)

in america's glacier land.

(music)

(playing america the beautiful)

(music)

(music)

america's northwest wears a white cap--

millions of acres of snow-covered mountains.

(music)

too frigid in winter for most life.

(music)

even colder are the glaciers, tucked among the peaks.

(music)

but believe it or not,

there are more creatures inside some glaciers

than there are people on the planet.

(music)

slithering just below the surface

is a familiar face you wouldn't expect to find

in a giant ice cube.

(music)

worms.

Not earthworms, but ice worms.

Billions of them.

(music)

anti-freeze proteins keep them from freezing solid,

and at night they squirm to the surface for a winter ball.

(music)

(music)

it starts with a feast.

(music)

they dine on algae trapped in the soft snow.

Then these kids dance.

(music)

it's party time for the wiggles.

(music)

(music)

sometimes more than a hundred join in.

(music)

scientists think this is more than a simple social event

or a way to get warm.

(music)

it's when mr. And mrs. Worm tie the knot.

(music)

the mating balls break up at dawn.

(music)

(music)

they quickly retreat deep into the ice and away from the sun.

(music)

a mere 40 degrees is enough

to start turning some worms into mush.

(music)

they'd be washed downstream in the snowmelt without a trace.

(music)

(music)

in the warmer months, glaciers are their salvation.

(music)

but these icy homes are disappearing fast.

(music)

glaciers tuck into mountains

across the western united states.

(music)

and although montana is known as glacier country,

scientists think they'll all be gone from here by 2080.

(music)

many creatures have a lot to lose,

even those who don't mind getting their feet wet.

(music)

(music)

grizzly bears once roamed as far south as mexico.

Now they're confined to the mountains.

(music)

montana's wild glacier country is their prized domain.

(music)

this young grizzly lost

about a quarter of his 600 pounds

hibernating over winter.

(music)

(music)

trout will help him put it back on.

(music)

it's a welcome treat.

And a swim takes the edge off the sun.

(growling)

fish are a small part of his diet

compared to berries and nuts.

He moves on.

(growling)

insects and larvae might hide under logs and branches.

(music)

it's worth a look.

(music)

to get the bugs out, just add water.

(music)

(music)

(growling)

(music)

a bit of a temper tantrum.

(growling)

(music)

or perhaps just fun.

(music)

(music)

his agility and speed are remarkable for his size.

He can sprint up to 35 miles an hour.

Over a short distance,

that'll keep him nose-to-nose with a horse.

(music)

he continues upstream on a never-ending search for food.

(music)

(growling)

(music)

90 pounds of food a day would keep him happy.

(music)

and in glacier country, he may just find it.

(chirping)

these rodents would certainly make a great snack.

This standing pose is how ground squirrels look out

for predators like bears.

Eat and look.

Dig and look.

Eat and look.

(music)

there's good reason for this vigilance.

(music)

they're vulnerable on the ground,

and trouble is never far away.

(music)

don't let this badger fool you with his cuddly looks.

(music)

even coyotes have been known to let badgers take the lead.

(music)

(music)

he moves in too close for comfort.

(chirping)

and a lookout warns the colony.

(chirping)

they all get the message.

It's time to run.

Hide.

(music)

(chirping)

(music)

(chirping)

(music)

the nearest hole is good if you're hiding from a bird...

(music)

but not from this guy.

He's designed to dig.

And squirrels are his favorite meal.

(sniffing)

spring in montana's glacier country

has left this soil soft.

Perfect for a badger

digging in pursuit of a ground squirrel.

(music)

his forelimbs have thick claws for breaking ground,

and his back legs act like shovels to scoop out the dirt.

(music)

some burrows have emergency exits.

But the badger is smart.

He breathes deeply into each hole...

(sniffing)

and smells his quarry below.

(music)

next he firmly plugs up all but one entrance.

(music)

now the squirrel is trapped.

(music)

the only way out is up.

And the badger has that covered.

(music)

game over.

(music)

instant death from powerful jaws.

(music)

and a hearty meal.

(music)

(music)

no wonder some small mammals

avoid digging burrows altogether.

(birds chirping)

a little higher up, the melted snow and ice

reveal mountains of boulders and rocks.

It's a labyrinth of nooks and crannies.

And the perfect domain

for a hardy and well-camouflaged creature.

(music)

(music)

the pika darts around these outcrops with ninja-like moves.

(music)

each dart, dash and sudden turn

helps protect him from predators.

(music)

he's hard to get a lock on.

But he claims his territory with distinctive calls.

(squeaks)

his squeaks and yodels echo off the barren landscape

as he sets about his main mission.

(music)

he's already preparing for next winter.

(music)

he'll spend the coldest months in tunnels, buried under snow,

up to 16 feet of it.

To survive he stashes a lot of food,

piling hay high in several stacks.

(music)

(music)

along with the grass and grain, an unsavory supplement.

(music)

he regularly eats his own feces.

(music)

there is a catch to all this preparation.

He runs a fine line.

He must work hard to prepare for winter.

But if he works too hard in summer, he may also die.

(music)

he's an expert at surviving the cold.

But not the heat.

Warmer days can be deadly.

Just half an hour exposed to 77 degrees,

and he'll perish from heat stress.

(music)

and when you run as many as 27 foraging trips per hour,

your odds of survival swing with the sundial.

(music)

it's what you have to do

to make it up here in glacier land.

(music)

make hay while the sun shines.

(music)

but now more than ever, the pika has to pace itself.

(music)

(music)

the loose, broken-up boulders of these upper scree fields

are fit for few mammals.

(music)

(music)

a marmot might move into such terrain.

(music)

but even he must make way for the true king of the mountain.

(music)

(music)

(music)

(music)

this mountain goat fearlessly climbs ever higher.

(music)

sunshine has him shed his winter coat...

(music)

and chase the receding snowline to dine on new growth.

(music)

he and his kin have serious predators to avoid.

Rising temperatures

bring wolves and mountain lions through here.

(music)

and this grizzly bear is out of hibernation earlier than usual.

He looks for a big meal.

(music)

(music)

the grizzly doesn't mind a bit of a climb...

If it means filling his belly.

(music)

the mountain goat's muscular shoulders

help haul him up the steep sides

of montana's glacial mountains.

(music)

his short legs lower his center of gravity,

making it easier for him to balance

on the narrowest of ledges.

(music)

(music)

it's a strategy that comes with risk.

In these parts,

17% of goat deaths are due to falling.

(music)

but when stuck between a rock and a hard place,

he chooses rock every time.

(music)

he can scale 1,500 vertical feet

in just 20 minutes...

And make rapid vertical descents.

(music)

(music)

even the bravest of grizzlies dare not follow.

(music)

the mountain goat is the most skilled rock climber

of all north american mammals.

(music)

goats hang on the sunny side and mow the fresh grass.

(music)

on the shady side of montana's mountains,

some lakes can hold icebergs all year round.

(music)

(music)

but even these chilled corners contribute to spring cascades.

(music)

(music)

among these flows,

the most unusual songbird you'll ever meet.

(music)

(music)

this is a dipper.

It's easy to see how she got her name.

(music)

she dips in...

And plucks insects straight from the flow.

(music)

(music)

she may plunge her head under up to 60 times a minute.

(music)

this songbird is less of a diva...

And more of a diver.

(music)

(music)

dippers are america's only truly aquatic songbird.

(music)

she'll happily travel up to 20 feet underwater.

A nasal flap closes her nostrils,

and transparent eyelids act like goggles

to help her see water bugs.

(music)

(music)

(music)

(music)

back on shore she easily sheds water

from her oily, almost waterproof, feathers.

Dippers never leave the company of water.

(chirping)

they have a sweet tune.

(singing)

but it's hard to hear over the flow.

(water rushing)

(water rushing)

(music)

this mom has a nest on the side of the cliff

behind the waterfall.

(chirping)

a safe place from predators.

(music)

mom flies to the nest as many as 18 times an hour.

Her chicks demand it.

(music)

these dippers may move to bigger streams in winter,

but they don't migrate south.

(music)

for many creatures,

glacier country is their one and only home.

That's even true for some of the fish below.

(music)

kokanee salmon were introduced to montana

more than a hundred years ago.

They're early settlers who stayed.

They don't migrate to the ocean and back

like some other sockeye,

but live in lakes or move up streams to spawn.

(music)

(music)

rainbow trout are here year-round, too.

They clear the streams of insects

and can weigh in at more than 30 pounds.

(music)

but there's a growing problem.

The warmer the water, the less chance their eggs will survive.

(music)

the same can be said for another aquatic creature.

One with an even stranger life cycle

that uses spring as a starting gun.

Ready...

Set...

Hop!

(music)

in montana's glacier land,

this western toad hibernates underground for winter.

(music)

now his pond is ready for him,

and he races in to look for a mate.

(music)

this toad lives at elevations up to 12,000 feet.

Even in spring, he likes things chilled.

Less than 50 degrees.

There aren't many romance options in the clear.

But among the reeds he finds his heart's desire.

(music)

he's a partner with attachment issues.

He has no intention of letting go.

(music)

no matter how far or how fast she swims.

(music)

(music)

nearby four or five other toad couples have the same idea.

(music)

they'll stay connected for a few hours.

Or even a few days!

(music)

the males just have to hope

that no nearby bachelors try to join the fun.

(music)

when she's ready, the female releases thousands of eggs.

(music)

the male fertilizes them as they leave her body.

The result is like a necklace.

Two strings with as many as 16,000 black pearls.

Fewer than 1% of these gems will make it to toad-hood.

Even less if temperatures get too warm.

(music)

(music)

warmer summers change life here in many ways.

Rivers flow fast with snowmelt.

These waterways bleed into mountain basins

and turn fields into shallow lakes and slush.

(music)

(music)

for some animals here, it's like a day spa.

(music)

time to kick back and enjoy the mud bath.

(music)

a glacial facial.

(music)

(music)

muskrat mornings are made for this.

It's a more leisurely time...

With meticulous grooming and big breakfasts.

(music)

they eat about a third of their body weight

in vegetation every day.

(music)

most of their busy work they do in the evening.

They use sticks and mud to build feeding platforms.

(music)

the water, even in summer, is still chilly,

and there are no robes at this resort.

The platforms let them warm up their naked feet and tails

while they eat.

(music)

they also have special control over their blood flow

that keeps their core warm.

When there's ample food,

muskrat populations can soar to as many as 36 per acre.

That kind of abundance attracts some unwanted attention.

(music)

the kind that can get you eaten.

(music)

the air may be clean and clear in montana's glacier land.

(music)

but that's no help

for a muskrat under aerial attack.

(music)

(music)

muskrats have poor eyesight and hearing.

(music)

(music)

her only hope for escape...

(music)

a last-minute duck dive.

(music)

her blood has a high tolerance for carbon dioxide.

That allows her to stay submerged

for as long as 17 minutes.

(music)

(music)

too long of a wait for this passing predator.

(music)

(music)

(music)

(music)

but there's something else lurking below,

bubbling in the depths of the marsh.

(music)

you've heard of the 'creature from the black lagoon'?

(music)

well, this...

Isn't it.

(music)

it's a ruddy duck.

(music)

within only a day of hatching, a ruddy duck can swim and dive,

and they spend the vast majority of their lives

in the water.

(music)

they duck down for long periods to scoop up mud

and filter it through thin plates in their bills.

(music)

they eat what's left:

Larvae, water fleas, worms and bits of plants.

(music)

(music)

they dip, duck and scoop, all day long.

Rain or shine.

(music)

and the muskrat huts give them a safe place to nest.

(music)

(music)

summer might be warmer than usual, but it's still short.

(music)

September, and a sudden flurry of snow.

(music)

the best place for a nest now is up in a tree.

Bird or not.

This squirrel is strictly nocturnal.

A snack of pine cone seeds is just as nutritious at night,

and the chances of being spotted by a predator are slim.

Slim, but not zero.

(music)

a pine marten.

A member of the weasel family.

A tree climbing specialist and a savage carnivore.

This squirrel is in deep, dark trouble.

A squirrel moves quickly through the canopy

of montana's glacier land.

But out on a limb like this, your average squirrel

has little chance against a pine marten.

(music)

(music)

but this is no ordinary squirrel.

(music)

(music)

(rustling)

he's a northern flying squirrel.

He has wings to glide.

All he needs is height for his takeoff.

And the pines give him plenty of that.

(music)

the membrane between his limbs keeps him aloft,

and his tail acts like a rudder.

If he chooses, he can make a 90-degree turn in mid-flight.

(music)

he's an impressive escape artist.

(music)

(music)

but the pine marten has super powers of his own.

(music)

(music)

he has no wings.

(music)

(music)

but the agility and strength to jump from tree to tree.

(music)

he follows the squirrel into another cavity.

(music)

(music)

but when he gets there, the cupboard is bare.

(music)

(music)

the northern flying squirrel stays one step ahead.

(music)

he'll live to see another winter.

And he doesn't have long to wait.

(music)

an icy breeze begins to chill glacier land once more.

(music)

down on the ground this female moose

brings her calf for a final fall harvest.

(music)

one more snowstorm will take grass off the menu for months.

(music)

but their spots at today's table are already taken.

(bellowing)

(music)

this group of males has the same idea.

(bellows)

and they can be dangerous.

Best to wait it out

and let the boys be boys.

(bellowing)

(urinating)

(music)

(bellowing)

(music)

(bellowing)

moose usually eat at a table for one.

(bellowing)

but these males are here to pack on the pounds in a rush.

And the best way to do that is to watch each other's back.

The more eyes you have on lookout,

the longer you can keep your head to the ground.

The fall rut, when males fight for females, has come and gone.

And the pecking order here is clear.

The size and shape of antlers say it all.

(bellowing)

the bigger and flatter the better.

(bellowing)

this guy's the big boss.

Flat with eight points.

(bellowing)

(music)

this male is less than two years old.

And with only four points on his antlers,

he's lucky the rut is over.

(bellowing)

but he'll keep his antlers the longest.

The bigger the rack, the sooner it'll be shed.

(bellowing)

(music)

with a shake of the head, some will lose

more than 70 pounds of weight in an instant.

(music)

(music)

(bellowing)

moose welcome the white.

(music)

the extra-hot temperatures

plagued them with swarms of biting insects.

(music)

now some relief.

(bellowing)

they hit their quota of food

by eating needles, bark, and branches,

as much as 45 pounds a day.

(music)

then winter buries it all.

(wind howling)

(wind howling)

snow covers the glaciers in a protective cloak of cold.

For a short time, it conceals the dramatic truth:

That every summer the glaciers get smaller.

(music)

over the years, these photos show

how much of the ice we've already lost.

Within 60 years, most, if not all the glaciers,

will be gone from montana.

Animals already struggle with the rapid increase in warmth.

(music)

pikas are at a greater risk of overheating.

(music)

fewer fish hatch from their eggs.

(music)

the same for toads.

(music)

for most of us, spring and summer

is a welcome escape from the harshness of winter.

But here, life thrives in the cold.

(music)

in glacier land, it's relief from summer that many crave.

(music)

in a place of great extremes there will still be snow...

And ice.

But as the glaciers diminish, the greatest extreme of all,

and the biggest challenge, is yet to come.