[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.
Each night, across the planet, our cities illuminate the darkness.
Their lights burning brighter than ever before.
And whilst we're asleep,
animals are making the most of this new neon landscape.
Chicago, a 600-square-kilometer city of lights.
This maze of concrete and glass canyons
provides the perfect home for the fastest animal on Earth...
the peregrine falcon.
[siren blares]
Peregrines are usually daytime predators,
but here in Chicago, a few have started to hunt at night.
[falcon screeching]
And there are certain times of year when they're active long after dark.
[siren wailing in distance]
[horn honks]
[birds twittering]
Each spring, millions of small birds pass over the city
on their migration north to breed.
They journey at night, when the air is cooler,
which saves them energy.
But as they fly over the city, the lights confuse them.
Mesmerized, they're drawn down...
and into this female's hunting ground.
[screeching]
Until now, nobody has ever filmed these predators hunting at night.
Striking fast-moving prey in the dark takes absolute precision.
Her best strategy is to climb high above the glowing city...
spot her prey below,
and then nose-dive...
becoming a 300-kilometer-an-hour neon bullet.
Using the sheer glass buildings as cover,
she can ambush her prey out of the shadows...
chasing them into the open, where there's nowhere to hide.
But the kill isn't for her.
This hunter is also a mother with three hungry chicks.
[chicks chirping]
With the migration well underway,
this female and her mate must keep hunting.
Amazingly, they can catch ten birds in just one hour.
Sixty years ago, there were no peregrines in Chicago.
Today, there are ten nesting pairs in downtown alone.
Helped by the lights of the city at night.
Across the world, nightfall brings great change to our urban areas.
Each night, billions of light bulbs burst into life.
A single streetlamp can now be 200 times stronger
than the light of a full moon.
With the nights lit up like never before,
the city offers surprising opportunities for a few bold animals.
-[crickets chirping] -[water splashing]
Los Angeles has a quarter of a million swimming pools.
In summer, when temperatures hit 100 degrees...
all this water is a vital lifeline...
for some unexpected visitors.
From bush crickets...
to woodpeckers.
Gray foxes.
Even shy mule deer are thirsty enough to risk a visit to this backyard pool.
But there's one midnight visitor you'd never dream of finding in LA.
[grunts, pants]
A black bear and her year-old cubs.
And they're here for more than just a drink.
When it's hot in the city,
they like a swim to cool off.
While we're asleep,
this family can enjoy their very own pool party.
Following Mum, these cubs have perfected their doggy paddle.
But, as every parent knows,
swimming with the kids isn't all that relaxing.
With her twins out of the way,
Mum finally gets the chance for some much-needed me time.
As our cities grow,
more bears are finding themselves in urban areas.
And incredibly, they're shifting their body clocks
to become more nocturnal.
For these bears, LA nightlife is sweet.
It's not just water that animals are seeking out after dark.
Nightfall is also the perfect time to steal a meal.
A nocturnal life of crime is making one city creature...
smarter than ever.
[sniffing]
[grunts]
The raccoon.
Tonight, this mother is leading her two young kits
out on one of their first night heists.
[sniffs, chitters]
Their turf: three square blocks in suburban Toronto.
Bandit-like face masks absorb light, reducing glare,
which helps them see in the dark.
And they're not fussy eaters.
But it's not just garbage on the menu.
These bright young raccoons are in training
to become skilled backyard burglars.
[chitters]
First, they must figure out the best way to break in.
Next, they must practice using their dexterous little hands
to get at tasty morsels.
They're endlessly curious, making them a family of criminal masterminds.
Until somebody lets the side down.
[dog barking]
[snorts]
[barking continues]
-Daring and complex raids like this... -[chitters]
...have made city raccoons even smarter than their country cousins.
And with 100,000 of them now in Toronto,
it's a suburban crime wave.
[chitters]
There are many stories of how animals must adapt
to live in our cities at night,
but one is truly extraordinary.
A top predator in one of America's largest urban jungles.
A stone's throw from the heart of LA lies Verdugo Mountain.
By day, it's a favorite spot for hikers.
But remote night cameras...
capture a surprising and secret nightlife.
[sniffing]
A pack of coyotes, six strong, prowl the hills at night.
They've become more nocturnal to avoid humans,
surviving on a diet of small mammals.
And the quiet of night is also when bobcats call to attract a mate.
[yowling]
But there's one animal here that's so elusive
no human has ever set eyes on her.
A mountain lion.
A big cat living in sight of downtown LA.
Until she was first caught on a hidden camera,
no one even knew she was here.
Her human neighbors have named her Nikita.
She patrols in the dead of night,
silently trespassing to make the most of the city's amenities.
Sharing these hills with large mule deer...
means there's plenty for her to hunt.
And our cameras reveal the hiding places
where she devours her prey away from prying eyes.
But the most astonishing thing about Nikita
is how she survives, surrounded by the city.
Today, her mountain home is encircled
by a barrier of concrete and freeways.
Whilst other mountain lions wander over an area of 200 square kilometers,
Nikita manages to thrive in a space only a quarter of that size.
Her territory is a dark island amongst a sea of lights.
But amazingly, she's been surviving here now for over a decade.
Nikita's future may be uncertain.
But for now, LA's secret big cat still prowls the shadows...
whilst we're sleeping.
The ultimate city survivor.
On location in Chicago,
the crew filmed peregrine falcons hunting at night for the first time.
But this was only half the story.
It's migration season,
when over 250 types of small bird fly over Chicago.
Following the same route from a time long before the city was even built.
The reflected lights dazzle the birds,
and many hit the glass windows.
As dawn arrives, volunteer Annette Prince searches the city streets,
hoping to rescue any injured birds
and recording those that didn't make it.
This is a ruby-throated hummingbird that we found just this morning,
very first thing when we arrived.
A little bird that flew all the way here from South or Central America,
across the Gulf of Mexico.
And to have it end when they're almost to their breeding grounds is pretty sad.
But they are even more precious 'cause they are the survivors.
This is the best little ruby-throated hummingbird
that didn't make it to his breeding ground.
[Tom Hiddleston] Across downtown Chicago,
Annette's team are searching for birds that need help.
Got him.
[bird chirping]
It's an ovenbird.
This guy comes from South America, Central America.
He probably flew across the Gulf of Mexico to get here.
So, this-- It's amazing they go this far and then hit a building here.
[Tom Hiddleston] During their morning patrol,
each bird Annette and her team find has its own sad story.
[Prince] He's very stressed. You see how he's open-mouth breathing like that?
On very heavy days of migration,
we've had as many as 300 birds injured and rescued,
and another 300 to 400 birds found dead.
So we can find hundreds of birds on single heavy days of migration.
[Tom Hiddleston] In one year,
Annette's team collected more than 5,000 birds from downtown Chicago.
Two-thirds of them were found dead,
making Chicago the deadliest city for bird collisions in America.
-[Kelly] ...got one on the street. -[Prince] Oh, boy.
[Tom Hiddleston] As this morning's patrol comes to an end,
Annette's team gather the birds lucky enough to get a second chance.
[Prince] Look at that. Isn't he beautiful?
It's an oriole. It's a male. He's getting his breeding plumage.
You can see he still has a little bit of speckling on his head.
So he has flown thousands of miles to get here, and he's made it.
And hopefully he's gonna get released and go off into a forest preserve,
where he'll find his way to where he wants to set up his nest for the summer season
and raise his young.
[Tom Hiddleston] In Chicago, there's now hope.
One hundred buildings have agreed to turn off their lights during the migration...
saving the lives of 10,000 birds.
With a staggering one billion birds
hitting buildings across America every year,
the future of many species could depend on the simple flick of a switch.