Night on Earth (2020) s01e05 Episode Script

Sleepless Cities

1 Cities.
The most unnatural places on Earth.
Concrete jungles, hostile to wildlife.
But at night it's a different story.
Under the cover of darkness urban worlds come to life.
Now, with the latest cameras we discover the remarkable ways in which animals are conquering this new nighttime world.
Welcome to the most surprising night on Earth.
After dark, we can appreciate how cities are taking over.
This is the fastest-growing habitat on Earth.
And it's forcing animals to find new ways to succeed in the night.
Early evening in southern Africa.
Led by their matriarch, a herd of elephants is on the move.
Following in the footsteps of her ancestors.
She knows the route by heart.
But today, their path is blocked.
In just two generations, this town has sprung up on the elephants' migratory path.
The good grazing is on the other side.
This herd isn't going anywhere until night.
It's only now when most people are tucked up in bed that they make their move.
The matriarch follows her nose.
Her sense of smell is four times better than a bloodhound.
With calves in tow, she sticks to the backstreets.
Some take a more direct route.
Main road, straight to downtown.
The world's largest land mammal slipping right through the center of town.
On cushioned feet, even a six-ton male can go unnoticed.
Still nursing her calf and with an enormous appetite of her own, the opportunity to refuel is too tempting.
But she needs to get moving.
Her herd must clear town before early morning traffic returns.
Using low-frequency rumbles, some so low, they’re inaudible to humans, the matriarch can communicate with the herd right across town.
Time to reassemble.
By learning how to navigate the city at night, this adaptable herd is keeping their ancient migration alive.
But while these elephants are just passing through, others come to our cities looking for a place to spend the night.
Vaux's swifts on a 5,000-kilometer migration down America’s west coast.
With night fast approaching, this huge flock need somewhere to sleep.
In the wild, they roost in tree hollows.
But this city provides a surprising alternative.
A towering chimney stack.
Right in the middle of Portland.
The swifts flock here in their thousands.
But there's a problem.
Cooper's hawks know they're coming.
They overnight here every year.
Right in the heart of his city home.
The swifts circle for as long as they dare.
None want to leave the safety of the flock.
But the temperature is dropping.
And cold can be an even bigger threat.
It's now or never.
One kill is a lifesaver for the rest.
Thirteen thousand swifts disappearing down a chimney in a rarely-seen moment of magic.
It might not seem the wisest place to rest, but realizing its importance, locals have taken the chimney out of use.
Safe and warm.
Portland provides a much-needed stopover on the swifts' epic journey.
But not all nocturnal visitors to our cities are so welcome.
In Mumbai, India, killers are on the loose.
This is one of the most crowded places on Earth.
Population – 20 million.
People are everywhere.
But few are aware of the danger following in their shadows.
Low-light cameras reveal the powerful predators stalking Mumbai’s streets.
More than 50 of them.
The greatest density of leopards anywhere on Earth.
All here to make a killing.
As the city sprawls around their forest home, they're learning how to survive on the streets.
This female waits till dark to slip into town.
Now, this potential man-eater can operate under the radar.
But she's not hunting humans.
Piglets are her preferred prey.
Her night vision is seven times better than a pig's.
They're oblivious to approaching danger.
But others can sense it.
Twice her weight, male pigs are formidable bodyguards.
It's not worth the risk.
With so many domestic animals here, she has options.
But she also has competition.
A male.
Bigger and bolder.
Every night, Mumbai’s backstreets play host to a deadly game of cat and mouse.
Most avoid built-up areas.
But the more brazen venture deeper into town.
Infiltrate buildings.
And seek a different target.
Every year in Mumbai, more than a thousand dogs are killed by leopards.
As natural food sources decline, more and more animals turn to our cities to satisfy their hunger.
24-hour surveillance is revealing an astonishing array of urban Intruders.
Across the globe, wild animals are growing ever more artful at stealing a meal.
Timing their nighttime raids to perfection.
In the wild, food becomes scarcer as winter approaches.
But in the city opportunities are endless.
Aspen, Colorado.
Just before they hibernate, these black bears hit downtown.
They must increase their body weight by a third to make it through winter.
That means eating over 20,000 calories every night.
The equivalent of nine large pizzas.
Their sense of smell is a hundred times better than ours.
Perfect for sniffing out a midnight feast.
Black bears usually forage by day and sleep at night.
But after dark, they can gorge on the vast amounts of food we throw away.
As it gets colder, the creatures visiting our cities get even stranger.
Halloween in Anchorage, Alaska.
The streets fill with goblins ghouls monsters and moose.
At this time of year, they usually feed on pine needles.
But for one night only, they're in town for a seasonal specialty.
Two meters at the shoulder, little stands in their way.
Each can eat 20 kilos of pumpkins in just a few hours.
Once they can eat no more they vanish like ghosts.
Most animals only visit urban areas looking for food.
But some have built lives here.
In Vienna, Austria cemeteries aren't just places of death.
They're full of life.
This female black-bellied hamster is part of a hidden community few people know exists.
Hundreds of miniature groundskeepers up all night clipping the lawn.
Everything a hamster needs is right here.
And now, this female's needs are growing.
Six newborn pups, just a few hours old.
Hungry, and entirely dependent on her.
She's got a busy night ahead.
But in midsummer, nights are short.
So much to eat so little time.
She must cram in as much as she can.
Stuffing her cheek pouches with ten percent of her body weight.
Time to offload.
Then back out for more.
Her frenetic activity doesn't go unnoticed.
A male.
He's got more than food on his mind.
Well, full marks for persistence.
But she's too busy to mess around.
Lost him.
At last.
Her young need to be fed around the clock.
In just three months' time, they'll be ready to have babies of their own.
Each female can have over 100 pups.
Little wonder the cemetery's population is booming.
But short legs can’t climb tall walls or cross busy roads.
Vienna’s hamsters are trapped with nowhere to go.
Life in an urban oasis has its limits.
To succeed in the city, animals must learn to negotiate the streets.
And master the art of dodging traffic.
Just like these nocturnal possums in downtown Melbourne.
They're smart enough to work out when to across.
And big enough to be seen when they get it wrong.
Under the cover of night, the streetwise can go forth and multiply.
And in some places, they're taking over.
It’s late in Lopburi, central Thailand.
By this time, most long-tailed macaques would be fast asleep.
But not this urban gang.
Though their night vision is no better than ours, city lights mean they can operate around the clock.
After a day spent in the sanctuary of an ancient temple it's time to hit the town.
Seven hundred-strong, this is one of the largest troops of monkeys in the world.
Ten times the size of a wild macaque troop.
The secret to their success is switching to a 24-7 existence.
They know there are easy pickings to be had after dark.
They also get a helping hand.
Monkeys are sacred around here.
The mob run riot through the city.
Taking everything and anything on offer.
But a life without limits comes with complications.
It's all too easy to overindulge.
For most urban macaques, the constant supply of food and water means they fare far better than their country cousins.
We're not the only primate to prosper in an urban environment.
But for some animals, the pace of change is too fast.
As the world cities expand, the dark and quiet of night is harder to find.
It's the 4th of July, and just across from Manhattan, a female diamond-backed terrapin is looking for somewhere to nest.
Her ancestors would have had access to the entire length of the Hudson estuary.
But those peaceful nights are long gone.
And tonight is especially hectic.
She's desperate to find a quiet spot.
And she's not alone.
All of New York’s breeding terrapins now nest here, in the only suitable bay.
The best sites are already taken.
And urban predators are waiting.
Raccoons eat their way through 90 percent of nests.
She'll have to look further into town.
She's searching for a dark, quiet patch.
But loud noises and bright lights are disorientating.
Finally, an unlit urban park.
But it's on the other side of the road.
Maternal instincts drive her on.
Despite the danger.
A long way from the estuary.
But still sandy enough to dig.
As soon as she's laid her 15 eggs, she must get back to where she started.
This year she's made it.
But her hatchlings' future is far less certain.
Light and noise pollution is changing the rhythm of life.
Blurring the distinction between night and day.
The same bright lights that allow us to live a 24-hour existence are having a serious impact on the animals with which we share our cities.
Scientists calculate that mammals become 30 percent more active at night when they live around people.
And the bigger they are, the more nocturnal they become.
With city lights outshining the night sky, animals can no longer navigate by the stars.
Just one of the many ways they are struggling to adapt to a brighter world.
But by simply switching off we could allow animals the darkness they need and let the stars shine once again.
As we design the cities of the future, we have the power to place nature at their heart.
And there is one place where this is already happening.
In the dead of night, low-light cameras reveal a remarkable sight.
A group of smooth-coated otters right in the center of Singapore.
Less than half a century ago, it would have been impossible to see them here.
But following a multi-million-dollar clean-up, the animals are returning.
Singapore is now one of the most wildlife-friendly cities in the world.
This is the largest otter family here.
Normally, otter pups move on when their mother gives birth again.
But here, three consecutive litters live together in one big happy family.
Why leave when you have the best territory in town? There's plenty of food.
And with sensitive whiskers, they can hunt through the night.
Full of fish, it's time to dry off and brush up.
It's also a chance to cement the bonds that keep such a large family together.
Every night, they patrol their home.
Marking the boundaries by rubbing their musky scent.
The message is clear.
This patch is fully occupied.
Although wild smooth-coated otters are active during the day, those that live in urban areas always become nocturnal to avoid humans.
Early risers begin to fill the pavements.
But here, the otters still have the right of way.
And incredibly, when most urban otters would be heading into hiding, these ones are still out and about.
Singapore a garden city with pristine waterways and more than two million trees, is providing the perfect environment for animals to revert to their wild ways.
To come back from the shadows and into the light.
Could this be a vision of the future? Where our cities provide a home for all sorts of wildlife not only at night, but also during the day.
In every habitat on Earth, night ushers in surprising behaviors and stunning spectacle.
We are only just beginning to understand how animals operate in the darkness.
Who knows what other secrets there are to uncover during a night on Earth?
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