All language subtitles for Yellowstone - The Wolves are Back _ Wildlife Documentary [DownSub.com]

In the northern Rocky Mountains

lies Yellowstone National Park,

encompassing
nearly 2.2 million acres.

Established in 1872,

it's the oldest National Park
in the United States

and the first in the world.

And it is home
to a unique set of fauna.

Bison were once the symbol
of the vast expanses

of the Wild West.

Here, they find
one of their last strongholds.

Below the surface of the ground
is a gigantic magma chamber.

The park is situated atop
the Yellowstone Caldera,

the largest
super-volcano in North America.

It was a major habitat for wolves

until they were mercilessly
exterminated 100 years ago.

Now they are back.

(wolf howls)

What has occurred since their return
amounts to a unique success story.

The wolves have transformed
the entire ecosystem

of Yellowstone National Park.

Yellowstone got its name

from the sulfur-rich rocks
common to the area.

It remains a largely unspoiled
wilderness.

But originally

Yellowstone was not set aside
strictly for ecological purposes.

The park was actually created
as a pleasure ground

for the enjoyment of the people.

Thus, humans created
a scenic resort,

an ideal representation
of wilderness.

A place where there was no room
for predators like wolves.

A 100 years ago

there were such a thing
as a good animal and a bad animal.

And bad animals were predators
because they killed, very visibly.

Wolves, cougars, bears, coyotes,
lynx, wolverine,

all those animals
killed for a living.

And our mindset then was,
that this is bad.

With the establishment
of the National Park,

the fate of the wolves was sealed.

So they were the bad animals

and good animals
were the plant eaters.

The animals that we wanted to hunt.

And so we wanted to nurture them,
grow their numbers,

to expand our opportunities.

And we wanted to observe them
because they were majestic

like the elk, the deer,
the pronghorn and the bison.

These were beautiful animals
that ate plants

and we wanted to grow them,
not predators.

So wolves were eliminated
from Yellowstone,

the last wolf was killed in 1926.

So we went through a 70-year period
with no wolves.

From time immemorial

wolves have been considered
bloodthirsty predators.

An enemy of mankind
that must be exterminated.

And that's what happened,
all over the world.

Yellowstone Park was no exception.

The extermination of the wolves

had catastrophic effects
on the ecological equilibrium

of the park.

The elk population began to grow
exponentially.

In the 1950s and 60s

the park administration tried
to control the population growth

by hunting and shooting the elk.

But without success.

Without wolves,
the elk had no natural enemies.

They were literally devouring
Yellowstone National Park,

eating young trees
before they could mature.

The northern Yellowstone elk herd,

which lives in the northern part
of the park, was overpopulated.

Right after we got rid of the wolves
and cougars

and bear numbers had declined,

this elk population had increased.

So the park service began
controlling elk numbers themselves.

They killed thousands of elk
over a 30-year period

because there were no predators.

And so that stopped in 1968

because our policy changed
and public opinion changed

and so the elk population
grew again.

From the late '60s to the early '90s
it grew dramatically.

This one herd was over 20,000 elk.

Many people felt that was too many.

That was impacting the environment.

Something had to be done.

In the 1960s
scientists fenced off this area,

to allow trees and shrubs to grow

without being eaten by elk.

The elk were a major attraction
of the park

and many visitors came to see them.

But at the same time,

the growing herds were destroying
the northern portion of the park.

Today, the fenced-in areas
are forests,

surrounded by barren steppe.

In fact, they ate all of it down
to this high.

This is what Yellowstone
looked like

for the middle part
of the 20th century.

The extermination of the wolves
was a fatal mistake.

A bitter fight ensued.

Ultimately, the government
in Washington came to a decision.

Between 1995 and 1997,
wolves were captured in Canada

and reintroduced
in Yellowstone National Park.

The main technique we used
to keep wolves here in Yellowstone

was acclimation.

We wanted the wolves
to stay in Yellowstone

and so to break that homing response

we held them in pens for 10 weeks.

And by and large it worked.

A couple of wolves took off,

but most of them stayed
within Yellowstone.

So we got a total of 41 wolves
from 1995 to 1997

that we let loose in this area
behind me.

The wolves reclaimed Yellowstone.

And did what was expected of them:

They hunted down
and preyed on the elk.

Today, the park is home
to just over 100 wolves

in 11 packs.

One of them is the Wapiti Lake Pack,

which makes its home in the center
of the national park.

(growls)

Led by a white alpha female,
the pack sets out on the hunt.

The herd is fast.

Suddenly, one of the wolves
finds itself isolated.

The hunter is now the hunted.

A fully grown, healthy elk
can overpower an isolated wolf.

A kick from its hooves can be fatal.

Without the help of its pack,
the wolf has no choice but to flee.

The Wapiti Lake pack retreats.

They are accustomed to hardship.

Only about one foray in five
is successful.

Sometimes they have to go for weeks
with nothing to eat.

It's the middle of May,

but cold weather has returned
to Yellowstone.

The pack has discovered the remains
of an elk carcass.

This gray wolf is Number 1091.

The white alpha wolf.

Some of these animals
wear tracking collars

and are known by a number.

This helps researchers study
their behavior.

There is a strict hierarchy
within the pack.

There are rules
about who gets to eat first.

The youngest has cut in line.

That might upset the older wolves.

The youngest wolf hesitates.

Should he relinquish the little food
that is left,

and possibly go hungry?

He would rather not risk a conflict
with the older wolves.

His submissive demeanor
makes it clear

that he accepts the rules
of the hierarchy.

And in the end, he gets his share.

For 70 years
there were no wolves in the park.

So the elk had no natural enemies.

But the wolves have been back
for 20 years now.

Have they succeeded
where humans failed for so long?

Wolves started preying on this very
large elk population right away.

And now, from 20,000 or more elk,
we have in this one herd

6,000 to 7,000.

We feel that's more natural.

That's how many elk there should be.

And there's cascading effects
from having fewer elk.

Those many elk
really impacted the ecosystem,

and now they are more in balance
with the ecosystem.

So in short,
wolves and this carnivore recovery,

but wolves are the middle of it,

have in a lot of ways
transformed this system.

The wolves have done their job well.

It's really an ideal success story.

But the white alpha wolf,

along with all the others wolves

roaming Yellowstone
for the past 20 years,

have achieved something
even more significant.

A natural balance.

Yes, they kill elk,

but they also promote life.

Coyotes play an important role here.

Without wolves,
there was a huge coyote population.

They were the park's
most successful predators.

And although coyotes don't kill elk,

they hunt down all the animals
underneath them on the food chain.

They prey on gophers,
chipmunks, squirrels, mice,

and newborn deer.

Since returning to the park, wolves
have been chasing their competitors.

The number of coyotes
has decreased considerably.

The beneficiaries
are the North American pronghorn.

Their population has been growing
since the wolves came back

and began decimating the coyotes.

Newborn pronghorn are a favorite
prey of coyotes.

So fewer coyotes means
more pronghorns survive.

Wolves don't bother them.

And the small mammals

gophers, chipmunks, ground squirrels
can relax a bit, too.

Which is good news for foxes!

Because with fewer coyotes,
there's more for them to eat.

There are more foxes
in Yellowstone now too

because fewer coyotes
means less competition.

And the majestic bald eagle
is also seen more often.

About ten years ago
their number was still decreasing.

Their primary source of nutrition,
the cutthroat trout,

was in danger of dying out.

But the bald eagles
found alternatives.

Now that there were fewer coyotes,

they were able to feed on squirrels,
mice and weasels.

But can the wolves' reintroduction
really be responsible

for the overall impact

on the entire ecosystem
of the national park?

Was it a chain reaction?

From the direct prey,

the elks, to the coyotes,
foxes, and even down to the mice?

Within a few years
of their reintroduction,

the number of wolves
had increased to 170.

For years now the number of wolves
has remained steady around 100.

But are 100 wolves,

at the top of the food chain,

enough to effect
such tremendous changes?

(howls)

The truth of what has happened
since the wolves' return

is more complex.

They didn't just impact the fauna.

After they came back,

aspens, willows and cottonwoods
began to grow again,

especially
in the Northern Range of the park.

Just a few years
after the wolves were reintroduced,

scientists
from Oregon State University

already began noticing astounding
changes in the park's flora.

Now, 20 years after the wolves
returned,

these aspens reveal the true miracle

that has occurred
in Yellowstone National Park.

We can see the browsing marks.

This stem has been bitten off
on the top

and if we look down,
we might see other evidence of this.

Here's another place
it was bitten off.

This is what was suppressing
the growth of young aspen

for most of the 20th century.

Amazing things
have happened in the park.

For decades all that grew here
were waist-high shrubs.

Now there are woods
and little forests.

We can see a stand
of tall, young aspen,

now growing into young trees.

These were not here 20 years ago.

If you had come to this spot
in 1997,

when the wolves
were being reintroduced,

there were no young aspen here
taller than about waist height.

They were continually
being suppressed.

And there were some aspen trees,
such as this dead snag here,

but they were dying out.

Sure enough,
in the northern area of the park

all that can be found growing
are 100-to-150-year old as pen

or small shrubs.

The trees are never more
than 5 to 6 meters tall,

and are 10 to 20 years old
at the most.

There's nothing in between.

Scientists determine the exact age
of the trees

to learn why these gaps exist.

Every year they record
the growth of aspen

at more than 100 locations
throughout the park.

With amazing results.

So it's by counting back
these growth nodes,

that we were able to find out

when these tall aspen
first started growing

and found
that it was in the early 2000s.

Then we looked at the base
and saw they used to be suppressed

but then they got released
from that.

Not a complete turn off of browsing

but enough
to get tall enough to continue.

This photo was taken in 2004.

Ten years later,

thick undergrowth
for the first time in decades.

This photo was also taken in 2004.

Today, these willow bushes
are two meters tall.

At first glance,
two meters is not very impressive.

But this is the first time
in a century

that aspen and willow
are growing in Yellowstone at all.

The ecosystem of the national park
is changing.

Is it because of the wolves?

The elk?

Can it be true that these few wolves
have had such a tremendous impact?

In Lamar Valley,
on the Northern Range of the park,

a wolf is preying on an elk.

The elk seems to have escaped
into the middle of the river.

But wolves are patient
and perseverant hunters.

They track their prey.

They know exactly
when the animal is tired,

or whether it has been injured.

When a wolf preys alone,

the hunt can stretch on for hours,

sometimes even days.

The elk is injured.

But the wolf holds back.

It will probably try again
within a few days.

Lamar Valley is home
to the Lamar Canyon wolf pack.

The alpha female
is finishing off a bison

and reacts to the howling
of the rest of the pack.

(howling)

The alpha wolf wears a tracking
collar identifying him as wolf 949.

His mate is pregnant.

Soon he will have to provide food
for the female wolf and their young.

So the female
is already teaching him

to regurgitate food he has eaten,

so he can feed her
and their young later.

But there is competition
with a neighboring pack.

Conflicts flare up repeatedly
over the course of the winter.

These intra-species conflicts

are the most common cause of death
for wolves in the national park.

The alpha female
of the Lamar Canyon pack

is eyeing a young buck deer.

It is not retreating
but is defending its territory.

Her son observes his mother's
technique from a safe distance.

The buck
doesn't seem to be intimidated.

The young wolf
is still too inexperienced

to be of any help to its mother.

Finally, she decides to attack.

But the buck fights back.

No lunch today.

Even though the wolves
are not always successful

the number of elk
has decreased significantly.

The wolves are transforming
the park.

Are they reestablishing
a natural balance

that has been disturbed
for an entire century?

It's summertime.

The alpha female
of the Lamar Canyon pack

appears emaciated.

The young wolves she gave birth to
in the spring have not survived.

They may have succumbed to illness,

or been killed by other predators.

And prey is in short supply.

The elk are still up
in the high pastures,

and won't return
to the valleys until late autumn.

In the first years
after they were reintroduced,

the wolves found plenty of prey.

Now that the elk population
has decreased so drastically,

they have to make do with less.

Wolves don't usually prey on bison.

This one probably died
from an injury.

Alpha wolf 949 found it
in the Lamar Valley.

But the neighboring pack

the Lamar wolves
have been competing with all winter

has also picked up the scent.

A single wolf has no chance
against so many opponents.

They would kill him.

The pack has discovered wolf 949.

He seems weak.

When the pack approaches,
he barely manages to escape in time.

Doug Smith, the leading wolf expert
at the national park,

is spending the summer
with other scientists

and researchers

to determine the impact
the wolves are having

on the entire ecosystem
of Yellowstone,

whether the wolves are transforming
not only the fauna

but also the flora of the park.

Scientists have been observing
and measuring this aspen forest

since 2001.

They measure the growth
from this mark each year.

There's lots of suckers.
Everything was browsed.

One member of the team
is Eric Larsen

from the University of Wisconsin.

Back in 1999 he was commissioned
by the national park

to investigate
why the aspen were disappearing.

The important thing about these
aspen is,

none of these were here
20 years ago

when we reintroduced wolves.

Either these were browsed down
by elk,

or they've since grown in.

So we are out here today
to measure these aspen

and try and figure out
what has happened.

Why has a thick forest appeared here
over the past 20 years,

after decades in which nothing
of the sort happened?

At first the national park
researchers were puzzled.

Suddenly, aspen trees were growing

where there had been
only bushes and shrubs.

From about 1700 until about 1930

there was continuous aspen
regeneration on the Northern Range.

And then in 1930 something changed.

Aspen stopped reaching tree size.
They were only in shrub size.

And the current on this one
is 8 centimeters.

What happened back then?

To find out, they extract samples
from the older trees.

The diameter gives an indication
of the age of the younger trees.

The question I asked was
what changed in the 1920s?

And the last recorded wolf killed
in Yellowstone Park was in 1926.

So aspen stopped regenerating

at the same time the last wolf
was killed in the park.

Does that mean the scientists
have actually found proof

that the trees stopped growing
when the last wolves were killed?

Or was something else responsible,

for example a forest fire,
or climate change?

What really happened in 1926?

It's called a trophic cascade.

The reintroduction
of this top predator, the wolf,

led to a reduction in the numbers
and in the browsing pressure

and the behaviors
of the elk population.

which, in turn, led to the aspen
being able to escape browsing

and grow into tree size.

This trophic cascade

is one of the most fascinating
scientific discoveries ever made.

The wolves were missing
from the ecosystem.

Their reintroduction
caused a chain reaction.

Well certainly wolves had a lot to
do with the recovery of these aspen.

But they are not the only agent.

Cougars were gone
and now they are back too.

Bears were here,
but their population much reduced.

Nature is always more complex
than we think.

But in this particular case
a key player has been wolves.

So was the missing factor
over those decades

the wolves
at the top of the food chain?

Yellowstone River
carries a massive amount of water.

The park is one of the most
important water reservoirs

in the northwestern United States.

From raging rivers,
to trickling creeks,

these waterways are the lifeline

for agriculture
and livestock farming

outside the park as well.

And in Yellowstone itself

they are the basis
for a highly complex ecosystem.

And within this, Mother Nature's
mighty landscape architects

play a decisive role.

Beavers.

They feed primarily on willows
and aspen.

They also use these trees
to build their dams,

turning the smaller
streams into ponds.

During the summer months,
they are busy eating.

Then in the fall
they repair their dams

using mud and branches,

making their lodge
in the center of the dam.

And willow bushes thrive everywhere.

Since the wolf reintroduction

and the decrease in elk
in this area,

and the corresponding decrease in
the willows being eaten by the elk,

the willows
have been able to grow tall.

Beavers have been able to use them
to build these dams.

Also some of the recovering aspen.

We're starting to see a restoration
of this ecological cycle

that will lead to greater expansions
of these wetland complexes

and also relieve some
of the restrictions of the streams.

They're narrow.

The streams will widen
and connect with the banks.

All this is really good for many
animal species and birds.

Ducks like to use the ponds.

Small song birds
like to nest in the willow bushes.

Many animals eat the willow bushes.

Many insects thrive in this habitat.

These wetland habitats
are biotopes, rich in diversity.

The primary food sources
for beavers, of course,

are the thriving willow bushes.

Is that the source of the chain
reaction?

Wolves decimated the elk population.

Fewer elk means fewer willow shrubs
being devoured.

For centuries, beavers were rare
in Yellowstone Park.

Now they are back.

And they are providing a new habitat
for many other species.

Among the beneficiaries

are the great blue heron.

Others simply enjoy a chance
to cool off.

Or a shortcut.

It's late August in Lamar Valley,

where Soda Butte Creek
flows into the Lamar River.

Still very weak, alpha wolf 949
is crossing a meadow.

He can hardly stay on his feet,

but doesn't appear to be injured.

Twice already there have been
outbreaks of a virus in the park,

and many of the wolves
became ill and died.

Is he sick?

He drags himself onward
until dusk falls.

Then...

he gives up.

For ten more days,
wolf 949 will fight death.

When he finally shows
no more signs of life,

national park rangers
collect his body

before other animals
and birds can get to it.

If he is carrying a disease,

any animals that eat his carcass
could become infected as well.

Wolf 949 died near a road,

so it was easy to find him.

Visitors and park rangers
spent the past several days here,

observing
his sad life-and-death struggle.

So folks, this is 949.

He's the alpha male
of the Lamar Canyon pack.

He is 6 years old.

He was born east of the park
in the Beartooth pack.

H e and three other Beartooth wolves
came over a year and a half ago

and joined the local pack.

And we don't know
the cause of death.

He's been here for the last 13 days.

He has not been able to move
or get up.

He could lift his head.

He didn't really seem to be
in distress or pain.

The crew will take him to a lab
in Bozeman for full analysis.

We think his younger brother
will take over as the alpha male,

so it will be a pack of one
adult male and two adult females.

So a small pack,
but that's a functioning pack.

A few weeks later,
the lab test confirmed

that wolf 949 was infected
with canine distemper virus.

Autumn is descending slowly
over Yellowstone National Park.

The white alpha wolf
from the Wapiti Lake pack

has been spotted again
in Hayden Valley,

in the heart of the park.

A few days after that
the pack led by the white wolf

reveals what they have been hiding
in the dense forest.

Newborn wolves,
three months old,

begin tentatively exploring
their surroundings.

All the baby wolves
born in the Wapiti Lake pack

have survived.

Was it really the wolves
that were responsible

for the trophic cascade?

Did they set the chain reaction
in motion

that gave beavers more to eat,

so they created more wetlands

that in turn provided a habitat
for other species?

Twenty years ago,
wolves were brought in

primarily
to reduce the elk population.

No one anticipated that their return
would result in more forests.

No one saw
this trophic cascade coming.

It really wasn't thought about
a lot.

So we made predictions
of what wolves were going to do,

to the elk population,

to the bison population,
to the deer population,

to livestock
when they left the park.

How much livestock
they'd take a year.

So a lot of predictions.

There really was not
any kind of prediction

on what it would do to the woody
vegetation, or the grasslands.

In fact some key wolf biologists

have been critical of our research
on trophic cascades.

They have said, this understanding
of what wolves do to ecosystems,

is incomplete or misunderstood.

Yet this has been
one of the hottest scientific topics

since wolves have been returned

and was almost not studied
beforehand.

Wolves are not really very good
predators.

Still, they were able to greatly
reduce the elk population,

allowing the vegetation to recover
in many areas of the park.

Fear might play an important role
in this equation.

Even if wolves don't always kill,
they still drive their prey away.

Many animals avoid areas

where they risk running
into their enemies.

What the landscape of fear,
that term means,

when you have an aspen forest

which is very thick,
which is very hard to see into,

it changes the foraging behavior
of the herbivores.

They're hesitant to enter this area

because they can be ambushed
very easily by bears or by wolves.

What I have seen
as I've measured aspen, is,

if you get a core
of larger trees in the center

and smaller trees out on the edge,

the elk will come
and they nibble on the edge

and they'll forage there

but they
won't go in the center of the stand.

This helps the stand to recover.

The real rulers of Yellowstone
National Park are the grizzly bears.

Apart from the wolves,

grizzlies are the most powerful
predators here.

Even the wolves back down

when one of the 1500 pound giants
shows up.

The only enemy the grizzlies
have to fear is humans.

Two one-year-old wolves
from the Wapiti Lake pack

are enjoying a meal
when they are suddenly interrupted.

A grizzly appears.

The young wolves run away
immediately.

One of the young wolves
is a bit audacious.

But the grizzly
quickly makes it clear to him

who's the boss.

It's smarter to back down

and keep a safe distance.

Meanwhile, the grizzly helps himself
to the wolves' prey.

But even the grizzlies
have competition.

In Hayden Valley
a bear comes across a dead elk stag.

But he is not alone.

A much larger grizzly
has also picked up the scent.

Knowing he is in the weaker
position, the younger bear submits.

Challenging the older bear
to a fight would be foolish.

A fatal faux pas.

The grizzlies enjoy an abundance
of food sources here.

Until a few years ago, that included
North American cutthroat trout,

before they were displaced
by the non-indigenous lake trout.

In the vicinity of Yellowstone Lake,

it is becoming more and more
difficult for them

to survive
on the few remaining cutthroats.

Lake trout stay in the lake,

and only rarely
venture upstream to spawn.

The grizzlies
have often been wrongly blamed

for the decrease
in the elk population.

Hunger sometimes drove the bears
to kill elk calves

to replace the trout
that were no longer available.

But there aren't enough bears around
Yellowstone Lake to be responsible

for the long-term decrease.

Besides, they are still able
to catch fish from time to time.

As the elk population decreases,

scientists hope the berry shrubs
will recover.

An ideal source of nutrition
for grizzlies and black bears,

who need to store a lot of fat
for their winter hibernation.

But at 8,000 feet, the high altitude
of the national park means

there will probably never be enough
shrubs and bushes here.

Luckily there are alternative
options.

In the autumn the black bears
climb ever higher.

The cones of the white bark pines
have a high fat content.

The bears use their climbing skills
to get at them.

They let the grizzlies have
the cones that fall to the ground.

The pine cones are full of calories,

so they are the best Yellowstone
has to offer

to help the black bears and
grizzlies store up the fat they need

to survive the long winter.

Grizzlies will eat virtually
anything.

When one source of nutrition
is not available

they simply turn to something else,

for example, maggots and grubs
and voles and other rodents.

And baby bears know that even grass
can be tasty.

So, if there are no elk around,

bears will always find something
else to eat.

Occasionally the Yellowstone
residents form unusual alliances.

For example, when wolves and
grizzlies start the day together.

This harmonious cooperation
is a partnership of convenience.

First, one of them
will be the better predator,

then the other.

Still, it's always advisable
to tread cautiously.

Friendship ends when they find
themselves pursuing the same prey.

Now, it doesn't matter
who is bigger or stronger,

but who is more stubborn.

The bison just stands by
and watches them fight.

The two rivals size each other up.

The grizzly
is becoming more aggressive.

But his showing off
doesn't impress anyone.

(grizzly growls)

Sometimes
perseverance is the best method.

Since the wolves returned
to Yellowstone 20 years ago,

they have worked wonders.

They reduced the elk population
from 20,000 to about 6,000.

But no one expected
that their impact on the ecosystem

in the northern areas of the park

would be so far-reaching.

We're expecting that Yellowstone
is never going to return

to conditions that it had
in the past.

But we're actually seeing aspen
stands pop up in places

with young aspen,

where they were buried in the bushes

and now they're starting to emerge.

I think we're going to see
an increase

in the growth of these woody plants

as we are entering into a time
of moderate browsing pressure

compared to what we used to have:

very high browsing pressure

that was suppressing them
almost uniformly.

Although other factors are affecting
the elk besides wolves,

this would not have happened without
the wolf reintroduction.

Late September.

The young wolves
of the Wapiti Lake pack

have already grown considerably.

The white alpha female

is preparing them
to survive the tough winter

in Yellowstone National Park.

There are more than 20 wolves
in their pack.

Whether the group stays that big

depends on whether they all find
enough food,

and don't have
to engage in hierarchy struggles.

Their rendezvous site
is in Hayden Valley,

on the bank
of the Yellowstone River.

The white wolf
is the undisputed leader

and focal point of the pack.

The search for food
governs their daily routine.

They hunt for prey every day,

so they can all survive
the hard winter months.

Then in early October,
the first snow begins to fall.

For 70 years,
there were no wolves in Yellowstone.

Their extermination
destroyed the entire ecosystem

of the National Park.

Now that wolves
have been reintroduced,

the original natural balance
is being restored.

It's truly a miracle of nature.

(howls)

Subtitles:
TI:ME:CO:DE-FILMSTUDIO, Kehl