Original subtitles

[bird caw].

NARRATOR: In a dark land of shadowy creatures.

[owl screeches].

One extraordinary mammal is armed to the teeth.

He tracks prey with bat-like senses.

And uses venom to strike like a cobra.

But nature has dealt this knight of darkness

a cruel blow.

He must eat every three hours or die.

[chewing sounds].

Such is the curse of the killer shrew.

[screeching].

Beware the danger that lurks below.

This is a northern short-tailed shrew...

one of the most remarkable species on the planet.

Don't be fooled by his mousy coat or his tiny eyes.

He is a formidable predator.

He devours up to three times his body weight every day

and leaves carnage in his wake.

There is a reason why taming a shrew is

notoriously difficult.

This footage is not sped up: shrews...

when awake... just never sit still.

The hearts of some shrews can race at more than

1,200 beats per minute...

sounding something like this.

[heart beating rapidly].

This hyper heart rate is one of Mother Nature's

cruelest blows...

a metabolism so fast shrews must feed almost non-stop.

Miss a meal and they perish within hours.

Shrews are animals of the underworld...

burrowers most at home within the earth.

But the need to feed will force this one

into the open...

to a kingdom where...

to eat... he must risk being eaten.

High up...

his lordship watches and hears all; while amphibious

soldiers surround a pond; and a wily thief...

a weasel... patrols the woods.

Meanwhile... deadly assassins stalk a fence-line;

and peasant mice work the crops.

In the underground: voles.

And around a farmer's barn...

the nobility.

Now...

enter a knight of darkness...

a forest-dweller on a quest:

A northern short-tailed shrew.

Nightfall signals a lucrative time to hunt;

the shrew is driven by an insatiable appetite.

But around the pond there's competition.

The green leopard frog or meadow frog...

is also known for its voracious appetite.

It will eat anything it can fit into its mouth...

including its own kind.

He is an ambush hunter and another who takes his meals

alive and writhing.

Where there is abundant food like this...

the shrew is not far away.

But why just have a juicy worm when you could have a

whole juicy frog?

The frog has leg power.

But the short-tailed shrew has a far more powerful

weapon in its arsenal.

It's one of the few mammals on the planet with venom.

It's delivered via grooves in his teeth.

Just one drop is enough to paralyze his prey.

The frog still breathes but can no longer move.

It will stay fresh while it's eaten alive...

bit by bit.

Green leopard frogs have been known to make the menu

in French restaurants.

Bon appetite.

It's a good meal...

and not a moment too soon.

The shrew is only awake for five minutes at a time.

His metabolism is so fast he'll sleep for the

next 25 minutes.

His entire life must be lived within five-minute

bursts of energy.

There's no time to waste.

All manner of dangers lay within the farmland

to the east.

But where the crops meet the forest is a likely spot

to find a mouse.

His eyes are small and his vision poor;

he can barely make out more than shapes and shadows.

But his delicate nose senses a trail.

He's not the only hunter here in the woodlands.

The least weasel is a cousin of the wolverine.

He is a ferocious hunter...

able to kill animals five times his size.

This shrew is much smaller than the weasel.

But they are competitors;

they both share a fondness for mice.

The weasel is the stronger of the two.

But the short-tailed shrew has a secret weapon.

[screech].

He wears invisible armor.

Scent glands on his belly and sides produce a

musky odor that repels other mammals.

The weasel backs off...

leaving the shrew to pursue the prize.

To get this next meal...

he must follow it to the farm...

crossing a perimeter patrolled by deadly assassins.

NARRATOR: In these hunger games...

the winner gets to eat the loser.

Reptiles like this garter snake can go weeks

without a meal.

But this shrew must eat its body weight every

12 hours or perish.

It's a standoff.

The shrew has earned a pass to enter the farmland

but his heart still races.

Now he has only minutes to find a life-saving meal.

And out here in the open; he's being watched.

[owl sounds].

This dark knight scurries through the crop fields...

desperate for a field mouse.

He finds passageways...

tracks made by another omnivore...

the vole.

The vole is still a rodent.

But larger than a mouse...

a heavy-weight contender.

Voles are notorious for killing plants...

even ringing entire trees.

But they also eat meat.

This one has made countless pathways and tunnels

through the fields.

But there's never room for a dangerous intruder.

To defend its terrain...

the vole must fight.

The vole fights for territory;

the shrew fights for survival.

He has a repulsive odor and deadly venom on his side.

But this shrew has an even greater imperative.

If he doesn't eat in the next few minutes...

he will die.

It's a bloody meal in the nick of time.

[chewing sounds].

Survival and rule...

over the tunnels made by the vole.

Piece-by-piece the shrew dines on the vole every

meal time until it's gone.

Then his doomsday clock starts again.

[bird caw].

He must head out...

a starving stranger in a hostile land.

[owl sounds].

NARRATOR: If he is to survive...

this the short-tailed shrew will need breakfast

in the next few hours.

Time to deploy one of his most amazing secret weapons.

[clicking sound].

This is the sound of sonar.

With a special recording device we can hear that this

shrew is making ultrasonic noises...

which bounce off objects ahead.

The echo allows him to see with his ears...

like a bat or a whale and navigate to his next meal.

Finally a mouse.

Grasses form a dense jungle when you're only

about four inches long.

The shrew's echolocation is hard at work

but how good is it?

He is on a deadline; but the mouse is still and silent.

[footsteps]

Then...a fateful move.

And the dark knight is ready to track and to tackle.

[making battle cries].

It's a fast battle but it's out in the open.

[chewing sounds].

The shrew is vulnerable.

[chewing sounds].

He must eat quickly.

The whole time he risks being discovered

by an overlord.

Owls hunt as much by sound as they do by sight.

[owl hoots].

Nighttime has been a slaughter of the weak.

Often in the shrew's favor.

But he is not only a predator; he is prey.

Time for the shrew to stash his food and run.

[owl sounds].

NARRATOR: The great horned owl swoops for the kill.

The shrew digs down for cover.

[owl screeches].

[owl screeches].

It works but the short-tailed shrew knows he

cannot hide here for long.

[owl hoots].

[owl screeches].

He's trapped...

forced to find food...

surrounded by predators.

Now the rising sun's warmth awakens even more hunters.

[rattle].

Heat-seeking sensors are an advantage.

Rattlesnakes threaten every small mammal in the area...

especially the weak and the vulnerable...

like these vole babies.

Voles are prolific breeders.

They are sexually mature after just one month...

after that they can have a litter of three to five

babies almost every month.

That would be an explosive 50 or so new voles every

year for each mother...

if nature didn't have its checks and balances.

This mother must head out for food.

She wanders close to the fence-line...

maybe too close.

This rattlesnake just delivered a death blow to

this mother vole.

The venom digests the vole from the inside out.

A cocktail of proteins and enzymes breaks down tissue.

One part causes blood cells to rupture...

while another prevents clotting.

Fiery pain... rapid breathing...

shock... then total organ failure.

Without their mother...

these vole babies face a slow death.

But the short-tailed shrew...

with its own highly toxic venom...

will take care of that.

A quick bite puts the young ones out of their misery;

the dark knight wastes nothing.

For a cursed creature that must dine every

two to three hours or die...

this is a feast.

Away from the rattler...

the shrew creates a cache in the old vole tunnel...

putting some of these dead infants away for future meals.

The shrew mus be brutal if it is to survive and have

young of its own.

Such a cache gives the shrew some comfort;

he knows where his next meal awaits.

Finally he can sleep sound or can he?

NARRATOR: A farmer's tiller seems harmless above ground.

But beneath the surface.

It's a double blow: The tunnels that once hid the

short-tailed shrew are lost; his food cache gone.

The farmer's field may now look in order.

But life becomes chaos for small creatures across

this kingdom.

Predators on the perimeter see opportunity

and seize it.

These fields leave our shrew exposed and vulnerable.

He has little choice... he's starving...

and he's not alone.

A relative...the pygmy shrew...

is also displaced by the farmer's tiller.

It's a face-off of killer cousins.

Two shrews...

both must kill and eat in the next few minutes or

die of hunger.

It's an incredible burst of energy and a battle

to the death.

The pygmy shrew is out-gunned in size and it

lacks the venom glands of the short-tailed shrew.

Our knight of darkness gets to live for at least

several hours more.

But now he needs a new plan.

Death patrols the perimeter...

so he heads to a barn for shelter.

Desperate for a guaranteed source of food.

Barns usually provide a reliable source of prey for

a venomous carnivore like the shrew.

But this one seems void of any signs of rodents.

Something has beaten him to it.

Our dark knight has unwittingly entered the

domain of a queenly killer.

[cat meows].

She's on it; a shrew would be a perfect cat snack.

It's a narrow escape.

[cat meows.]

He seeks cover under some old hay;

bad idea.

[rattle].

NARRATOR: This short-tailed shrew has spent

all his waking minutes dodging one threat after

another and another.

It's a lucky escape.

But he's expended valuable energy.

And he's had no time to hunt.

Desperate... this carnivore tries nibbling

some spilled corn.

But it's not meat... not enough.

He's weak...vulnerable... and those who watch from

above know it.

[owl screeches].

[chewing sounds]

It was a short...

dirty life for this knight of darkness.

Armed with venom and echolocation but cursed by

the constant need to feed.

There is no happy ending for this dark knight.

No time for a mate.

Never enough time to rest.

Such is the lot of shrews...

a creature stuck in a Middle Earth...

both vulnerable prey and savage predator.

[screeching].