[Tom Hiddleston] The night.
A shadowy world that hides more than half the animals on our planet.
Until now, cameras only offered a glimpse into their lives.
But with next-generation technology,
we can see the night as clear as day.
With cameras a hundred times more sensitive than the human eye...
we can now capture the beauty of night...
in color.
Alien landscapes.
Strange creatures brought to life by the darkness.
Unseen behaviors.
Now we can follow the lives of animals
in Earth's last true wilderness.
The night.
[birds twittering]
The dusty plains of Zimbabwe.
At the height of the dry season.
As day draws to a close...
a family is on the move.
Mothers, sisters, aunts and cousins
on a migration to find water.
They're led by the oldest, most experienced member of the herd,
the grandmother.
[elephant trumpets]
Her family has four calves to look after.
One, an infant born just a few months ago.
She leads them all...
following paths etched in her memory.
But the promise of finding water across this parched land...
all too often ends...
in disappointment.
[insects chirping]
This summer, the elephants of Southern Africa
have been through their worst drought in 40 years.
Many of the water holes that are the lifeblood for animals here
now offer little more than a mud bath.
Elephants can only survive for three days without drinking.
They must find water soon.
-[insects chirping] -[birds twittering]
As the sun sets, the heat of day begins to fade.
The herd can travel vast distances in the cool of night.
We've never been able to see what happens on these epic nocturnal journeys.
But with cameras that can film by moonlight...
we can now show what the world's largest land mammal gets up to at night.
Elephants don't just use their vision at night.
They also have the most sophisticated night navigation equipment:
a two-meter trunk that they use like a periscope.
With twice the scent receptors of a bloodhound,
they raise their trunks to scan the darkness,
picking up tiny odors on the night breeze.
They can pinpoint the location of water...
from over a kilometer away.
At night, the herd also changes the way it moves.
They walk in tighter formation,
protecting their calves in the middle of the herd.
If anything ever scares the little ones...
[trumpets]
...there's always an adult nearby to comfort them.
And the family are right to guard their youngest.
[elephant rumbling]
At night...
it's hard to see what's lurking in the shadows.
But our cameras show the dangers they face.
Lions.
There are prides here that specialize in taking down elephants at night.
They wait on known routes to water.
On the lookout... for a target.
Sensing trouble, the family moves quickly on.
Elephants can travel at over 20 kilometers an hour.
But the youngsters can't sustain these speeds for long.
All the lions need to do is keep up the pressure...
and wait for their chance.
In the rush to get away, a calf has become separated from the herd.
It's small enough to be taken down by just one powerful lioness.
[trumpets]
An alarm call alerts the herd.
[trumpeting]
A family of three-ton elephants
can see off even the biggest pride of lions.
[trumpets, bellows]
[elephant rumbling]
Herds with the most experienced leaders
stand the best chance of saving their young ones.
But the family will face even greater threats in the nights ahead.
Hidden in grassland, at the elephants' feet,
is one of Africa's most secretive nocturnal foragers.
[sniffing]
It may look like a tiny dinosaur,
but this is the world's only fully scaly mammal.
The pangolin.
They spend their days in burrows and only venture out after dark.
[sniffing]
They track down insects at night with an exceptional sense of smell...
rooting them out with their long, curved claws.
Tonight a trail of ants has led this male out of his comfort zone.
There are some species of pangolin that have adapted to climb trees.
But this...
isn't one of them.
The ground pangolin may be no tree climber...
but he can walk over six kilometers on a single nightly forage.
What he's really on the lookout for... is this.
A giant termite mound.
For a hungry pangolin, this is a towering treasure trove of treats.
Using a sticky tongue...
[sniffs, licks]
...that's almost as long as his body...
a pangolin can eat up to 30,000 insects a night...
in what has to be one of Africa's most bizarre midnight feasts.
A week has passed.
The elephants are still searching for water.
They've survived so far by draining the last drops
from dried-up water holes en route.
The oldest member of the herd must lead them to water soon.
With a mental map formed over decades,
she's brought the family to an ancient seep,
where water oozes up from underground wells.
It's a hidden lifeline in times of drought.
The elephants can smell the water through the earth,
and they know that to get to it, they must dig.
For the adults, it's easy.
But for calves...
it's more of a challenge.
They won't have tusks to dig with until they're two years old.
Tonight their chance of a much-needed drink
is about to be cut short.
[elephants rumbling, bellowing]
The herd seems spooked.
In the darkness...
[low howling]
...it's hard to see what's out there.
But night cameras reveal...
a gang of hyenas.
They've been attracted here by a large antelope known as a kudu
that's become stuck in the mud.
[low howling continues]
-[laughing sound] -[elephant trumpets]
[rumbles, bellows]
An adult elephant is 40 times heavier than a hyena.
But the herd knows their little ones could still be at risk.
It's time to move on.
Everyone will need to keep up.
The kudu is hard to reach.
[groaning]
The hyenas can't risk getting stuck in the mud themselves.
[howling]
But in the moonlight the gang spots a more tempting target.
A mother nursing her newborn calf, less than a month old.
[trumpets]
-[laughing sound] -[elephant trumpets]
She's anxious, only now realizing they've been left behind.
-[laughing sound] -Hyenas aren't usually a threat,
but in this one part of Southern Africa
they've been known to attack elephant calves at night.
-[elephant trumpets] -[hyenas whining]
Hyenas have a chilling way to hunt young elephants.
They target the tail.
If they can grab it...
they'll pull the calf off its feet.
[laughing sounds, whining]
The mother must keep her little one under her legs to protect him.
But whenever she tries to lead him to safety,
the calf is left dangerously exposed.
-[trumpets] -[bellows]
More hyenas join the attack.
The mother has nowhere left to turn.
But their struggle...
[elephants rumbling, trumpeting]
...has been heard.
[laughing sound]
[trumpeting]
[trumpeting continues]
[laughing sound]
-[trumpets] -[hyena growls, whines]
In the darkness, the elephants' tight family bonds...
have allowed the herd to save their most precious new arrival.
[thunder rumbling]
Distant storms mark an end to the drought.
Amazingly, elephants can detect low-frequency rumbles of thunder...
from 100 kilometers away.
It's believed their highly sensitive feet pick up vibrations through the ground.
Instinctively, the oldest member of the herd
leads her family towards the rains.
After journeying for weeks...
and conserving energy by covering hundreds of kilometers
in the cool of night...
this family finds what it's been looking for.
Following elephants through the night...
has shown just how vulnerable the largest land mammal can be after dark.
And how far the herd must go...
to protect their young...
from the unseen trials of night.
The Earth at Night team scoured the plains of Southern Africa over two years...
to reveal the lives of elephants after dark...
and the challenges they face from nocturnal predators.
[man] Lions are very successful as predators,
in that they actually hunt in numbers,
and that's why lions can take down animals which are much bigger than themselves.
[Tom Hiddleston] The elephants of Zimbabwe are vulnerable to attack at night,
and rapid changes in our climate are making things worse.
Facing the most serious drought in four decades...
more elephants than ever have been forced to gather around
whatever water they can find.
And lions have learned to take advantage.
[Varley] There's well over 35,000 elephants,
so everything has to come to very few, um, remaining water holes.
The lions have figured out that it's the most abundant food source for them.
Um, so eventually they gotta learn how to take them down.
[woman] Currently, with my own eyes, I can't see anything at all.
I can just hear some lions just outside here.
But unfortunately the moon's not quite up yet
so we're checking on the app.
We've got about another 15 minutes until the moon comes up.
[Tom Hiddleston] With lions around,
the crew had to film from specially adapted vehicles
fitted with gyro-stabilized moonlight cameras.
[mechanism whirring]
When I move my hand across this joystick, it makes the camera move.
You can see just how dark it is out there.
It just unlocks a whole new world of seeing things.
[Tom Hiddleston] Night after night, the team followed the herd
on their perilous journey through lion country.
But an unexpected threat emerged, taking the crew by surprise.
[Varley] Are those hyenas? Where the hyenas?
[Godwin] This could be interesting.
[Varley] He's at 11:00.
-[Godwin] Okay, focus... -Yes, I'm on the baby anyway.
Nice one. She's nipping the back.
[Tom Hiddleston] Research shows that when seven or more hyenas hunt together,
they can kill an elephant calf.
[Godwin] There's a hyena. He's running towards the kudu now.
They're going in now, so just keep a wide.
[Tom Hiddleston] It was a true life-and-death struggle in the darkness...
[laughing sound, growls]
[trumpets]
...that had never been filmed before.
-[laughing sound] -[elephant trumpets]
Following elephants at night over two dry seasons
gave the team a fresh insight into the world's biggest land animal.
It showed the true power of these majestic animals
comes from the herd sticking together as one.