Original subtitles

SIREN WAILS

Cities...

..the fastest-growing habitat on the planet.

A land of opportunity...

..for animals of all shapes and sizes.

This unnatural world... CAR HORN

..presents unique challenges...

..but for those able to adapt...

..and take advantage of the riches on offer...

..the urban jungle

is quickly becoming the new wild.

Home to more than half the world's human population,

cities can be hectic and intimidating.

Life here moves pretty fast...

..at least for some.

Born into the heart of Singapore,

these smooth-coated otter pups

are the newest kids on the block...

..and they are about to learn what it takes to be

a wild city resident.

In a natural world, this otter family would move den

if they thought there was a predator in the neighbourhood.

They have few in the city,

but old habits die hard...

..and at ten weeks, the pups are strong enough to move house

for the first time.

They will learn everything they need to know

about life on these streets from their parents.

Partners for life, they've learnt the importance

of sticking together,

something this family will need to do

if they are to make it safely across town.

And, only a few metres in,

they hit their first obstacle.

It's a walk in the park for any seasoned citizen.

Most of the pups get the hang of it quickly...

..but there's always one.

Luckily for him,

Singapore is packed with waterways...

..and, being semiaquatic, for an otter, they're a perfect way

to navigate this urban landscape.

More than 600 miles of canals and rivers

crisscross the city.

The pups have only recently learned to swim...

..and just over one mile into their journey,

they're running on empty.

But for otters, Singapore's clean channels

are far more than just transport links.

They need to eat nearly a quarter of their body weight

in fish every day.

The young pups can't catch their own yet...

..but with older siblings that can,

they just need to work out who's willing to share.

you never know who or what you might run into.

DOG BARKS

But as they would in the natural world...

..these urban otters work together...

..and as a gang...

..they can overcome just about anything.

The older generation of Singapore's otters

have got life on the streets worked out.

The urban world is their oyster...

..and on their way to a new home,

they're passing down their know-how to this new generation.

Singapore's otters have everything they need to survive...

..food, water,

and even secure, hidden corners to grow up in.

It's a recipe for success.

And with their ability to live alongside us...

..they aren't just surviving,

they're thriving.

The family's doing so well,

it's three times the size

of the average otter family outside the city.

And, like them, many species are discovering

that moving into town suits them better

than staying in the natural world.

Some have little choice,

as we continue to cultivate vast areas of land

to feed our rapidly growing urban population.

Driven by necessity, the smartest animals

have followed the food into town.

Here in Thailand, these long-tailed macaques

are known as the Temple Troop.

Treated like royalty, they're fed every day.

The Temple Troop have inherited the best address in town.

They live off the fat of the land

and spend their day barely lifting a finger.

Born on the other side of the tracks,

this young male is part of the Mafia Troop.

Life for them isn't so easy.

They have to work a whole lot harder than the Temple Troop

to get their cut of the food on offer here.

But as established residents, the Mafia Troop

know the best spots in town to grab a bite.

For them, it's all about timing...

..knowing when to stop... HE WHISTLES

..and when to go.

The Mafia Troop youngsters learn the tricks of the trade by example,

and they have no shortage of role models.

And while they have worked out how to take what they need

from their human neighbours,

they've also learned some open their doors to them.

Sutit Tantiwong lives and works in the centre of Lopburi.

Like all long-tailed macaques,

the street-smart Mafia Troop are curious by nature.

And while the Temple Troop take time out for grooming...

..the Mafia Troop are always on the move.

They spend their time exploring the neighbourhood.

And with every new experience, there's something new to discover.

In Lopburi, they're finding everything they need is on tap.

Just around the corner, some members of the Temple Troop

are enjoying their life of luxury...

..and don't give a second thought for their would-be rivals,

the Mafia Troop.

Lopburi's city-savvy long-tailed macaques

have successfully swapped the rain forest for a concrete jungle.

Here, their numbers are booming.

Almost 1,200 of them live as neighbours...

..and lead a far more peaceful existence than their rural cousins

in the forests of Southeast Asia...

..all thanks to being so well fed.

While food draws many animals into town,

it's not the only reason wildlife chooses to stay.

Most big cities are built on sites

that are rich in natural resources.

South Australia's capital is no different.

The River Torrens feeds the largest

inner-city park system in the country.

And the city's botanic gardens

provide a permanent oasis for humans and animals alike.

Rainbow lorikeets like the easy life in the centre of Adelaide so much,

they've given up migrating and now live here permanently.

In 2010, following the worst drought in a century,

a 500-strong wild crowd were forced out of their home

in the Australian outback and joined the lorikeets.

And they liked it so much, they hung around.

With access to life-saving refreshment,

20,000 grey-headed flying foxes

now call Adelaide home,

in what's known as a camp.

They spend their days roosting high in these pine trees.

But life in a city isn't what they're used to.

It's crowded...

..very noisy...

..and in summertime,

with the arrival of a series of music festivals,

it gets even louder.

DANCE MUSIC

And that's not all.

In the past two decades,

south Australia has been getting hotter.

Temperatures here can top 40 degrees.

Everyone feels the heat.

Flying foxes are covered from ankle to nose in fur,

and they can't sweat...

..so if they overheat, they'll die.

As they would in the South Australian bush,

they find shade amongst the lower branches

and do their best to cool down.

Nocturnal by nature,

they'd normally stay in camp during the day.

But dehydration is a real threat...

..and desperate times call for desperate measures.

Leaving the trees, they head for the lifeline

that first drew them into the city...

..the River Torrens.

Today, it's a sweltering 43 degrees.

Belly dipping is an instant life-saver for the bats.

It cools them down

and gives them a chance to grab a welcome drink.

Back in the shade, they lap up any remaining water

from their soaked fur.

Elsewhere in Australia, tens of thousands of flying foxes

have died because of the heat...

..but, here in Adelaide, this camp has found a way to beat

the rising temperatures.

As the cooler evening approaches,

they begin to spread their wings again...

..ready for a night of foraging for fruit and nectar.

From bats to boars,

raccoons to red foxes,

our best-loved cities are already home to much more wildlife

than most of us realise.

That's in part because the city never sleeps.

And in Thailand's capital,

working the night shift has certain benefits.

Reticulated pythons are the longest snakes on the planet.

They can grow over ten metres

and weigh as much as 150 kilos...

..but many of them still manage to live a secretive life

in the heart of Bangkok.

Pythons are most active under the cover of darkness...

..and travelling at night, they move virtually undetected.

By filming under controlled conditions,

we can reveal what life's like for these city slickers.

They survive feeding on birds,

rodents, and other animals they can ambush.

When they catch prey, they coil tightly around it,

cutting off its blood supply,

and stopping its heart.

But to make it here, every true wild resident

needs to find more than just food.

They also need somewhere safe to start a family.

This residential garden is a haven from the busy city streets.

And when pythons want to nest,

they search out a safe and concealed spot like this.

This python is laying what's probably her first ever

clutch of eggs.

Instinctively, she wraps herself around them

to regulate their temperature

by expanding and contracting.

This is known as brooding.

A nurturing mother, she'll guard them with her life.

Pythons stay with their eggs for three months

and only leave when they're ready to hatch.

When eventually that time comes,

the new arrivals are on their own,

primed to catch and eat

what they need to survive.

Reticulated pythons have been residents in this area

since long before the city was established.

With plenty of food and hidden places to nest,

thousands of them are still at home here,

even though tarmac and concrete

cover the wetlands that Bangkok now stands on.

In fact, many animals have found the bricks and mortar

we've built our cities out of

provide just the safe shelter they need.

And one urban veteran has flourished...

..living right under our feet...

..even earning themselves the name pavement ants.

This colony is busy raising its next generation...

..taking advantage of the warmth absorbed by the paving stones

to nurture precious larvae.

Believed to have lived in our cities since Roman times,

pavement ants are one of the oldest urban residents of all.

Like many established New Yorkers,

this family's ancestors emigrated from Europe...

..and managed to bag a city home on Broadway.

For generations, they've lived here safe and secure,

whilst quietly providing a vital service to us.

With more than 8.5 million people living here,

New York is America's hungriest city...

..and one of its most wasteful.

New Yorkers throw away over a million tonnes of food every year.

But for pavement ants in the Big Apple,

wasted food is opportunity.

With very poor eyesight,

this scout relies on her antennae to move around.

They help her track down her next meal

within seconds of it hitting the ground.

True fast food.

Hot dogs aren't pavement ants' natural diet,

but they can't get enough of them.

And once they've found a good place to eat,

the ants quickly spread the word.

They communicate using their antennae.

It's called antennating,

and relays all the information

the colony needs to find the takeaway.

In no time, the hot dog's swarming.

Without antennae, pavement ants would be lost...

..so they keep them squeaky clean.

These fastidious insects are barely noticed by most humans

and busily clear the streets of New York of wasted food.

They consume the equivalent of 60,000 hot dogs a year

from Broadway alone.

By doing so, they've become by far the biggest gang in New York.

With an estimated population of more than 1.6 billion,

they outnumber New Yorkers nearly 200 to 1.

Pavement ants have found a home under our busy streets

that suits them down to the ground.

That's because our cities provide many of the same things

animals look for in nature.

Urban parks imitate jungles and grasslands,

with predators like jackals taking up residency

and raising their young.

Even roadsides provide unlikely havens

for animals like bark scorpions to breed.

And city buildings across the world mirror clifftops,

and have seen peregrine falcons move in to hunt.

In fact, there's so much competition for a permanent home in urban areas

that some animals are dramatically changing their lifestyle

to try and secure it.

BELL TOLLS

For centuries, hundreds of white storks have been visiting

this ancient Spanish town for a few months a year

to nest and raise a family.

Some fly nearly 4,000 miles to be here, migrating from Africa.

Alfaro's terracotta rooftops provide them with a perfect summer home.

And their custom-built nesting baskets take urban living

to a whole new level.

The storks are in strong competition for these prime nesting sites.

With a gruelling return flight to Africa to prepare for,

these chicks would normally have to quadruple their weight

in just three months...

..but these canny urban storks have discovered a secret

that means they can avoid the long migration

and hang onto their nest site year-round.

And the secret is landfill.

Humans generate ten times as much waste as we did a century ago.

But one man's waste is another's treasure.

Picking through rubbish can be a risky business...

..but with so much at stake, the pros outweigh the cons.

Storks flock to landfill sites across Europe for their share of

the 250 million tonnes of food we throw away every year.

Landfills provide a daily picnic, even in the coldest months.

And in the past three decades, huge numbers of white storks

have swapped their 8,000-mile annual round trip

for a permanent home in Spain.

Moving with the times, it's win-win for Alfaro's shrewd storks.

It shows just how versatile urban wildlife can be

as it adapts to our world in ways we could never have predicted.

One of Britain's rarest amphibians,

great crested newts,

are cumbersome and vulnerable in the open.

But they can find safety even in the most unlikely of places.

Underwater, newts move with speed, and are voracious predators.

A caddisfly larvae is the perfect snack.

Satisfied, she sets her mind to the task at hand.

Laden with around 250 fertilised eggs,

she needs somewhere safe to lay them.

She's looking for a pliable surface to protect them.

Great crested newts evolved to lay their eggs within submerged leaves

but, after millions of years on the planet, they're resourceful.

This plastic bag shouldn't be here,

but it's flexible and will make the perfect substitute for a leaf.

She makes a fold in the bag

and lays one egg in it...

..then gently wraps it up with her hind feet.

A sticky glue-like jelly around the egg will help keep it safe.

She squeezes the plastic together

and holds tight for long enough to allow the jelly to fix.

Over the next few weeks,

she'll lay around ten eggs like this every day...

..protecting each one in its own secure pouch...

..and giving her offspring the best chance of making it.

It's an extraordinary adaptation

to survive in a new and changing world.

Life in the city isn't always straightforward...

..but for wildlife to succeed,

it must be able to cope with whatever we throw at it.

And our busy, noisy lifestyle is something all wild residents

must come to terms with.

This long-eared owl has found a roost in this Serbian town...

..and she's not alone.

A large group have gathered together in what's called an owl parliament.

They find shelter in the town square when temperatures plummet.

Dense evergreen trees protect them from the wind

and help them stay well hidden from predators.

CHILDREN CHAT AND LAUGH

But for a shy, sensitive animal that needs to rest in the day,

the secret to success is their ability to cope with us.

INDISTINCT CHATTER

They've learned to tolerate the bustle of urban life...

..and the townsfolk are learning to respect the owls too.

LAUGHTER AND CHATTER

These owls wouldn't be here in such numbers if weren't for us.

They flock to Kikinda,

seeking refuge after the devastating Balkan wars in the 1990s.

Miroslav Grujic lived through the conflict too.

TRANSLATION:

With the fuel supply cut off,

forests across Serbia were chopped down to burn.

Over 90% of the trees in the area were cleared,

leaving the owls with nowhere to roost in winter.

So they moved into Kikinda,

and Miroslav believes the owls have helped to transform the town.

The owls have found a place to shelter in town and are thriving,

and they've brought hope and light here in the midst of winter.

Elsewhere, the owls sometimes roost in small groups

but Kikinda's town square now holds more than 750 of them

in what is by far the largest long-eared owl roost in the world.

It's estimated that 40,000 long-eared owls

now live in towns across Serbia.

Through winter, the only time they leave their urban roost

is to hunt in the nearby fields.

Like the owls, a growing number of animals are moving into

our towns and cities

to take advantage of the food, water, and shelter on offer.

What's perhaps most surprising

are the relationships wildlife is striking up with us,

and the depths these are going to.

Built on the banks of the Tocantins River in the Brazilian Amazon,

the city of Mocajuba is growing fast.

On the edge of town, a small group of fishermen

have forged a very special friendship

with some of the neighbourhood's most established residents...

..river dolphins.

This species was only identified in 2012,

the first such discovery in nearly 100 years.

They can grow over 2.5 metres long

and weigh more than 200 kilos.

Unlike most marine dolphins,

their bodies are extremely flexible,

enabling them to manoeuvre through the Amazon's famous flooded forest

in pursuit of fish.

River dolphins are normally shy...

..but the pod in Mocajuba

has struck up a partnership with Braz Silva and his son Osvaldo.

They've fished this stretch of river for decades

and, in recent years, the river dolphins

have joined the family business.

Braz and Osvaldo give the dolphins an incentive to stay nearby...

..and the very presence of these apex predators

helps to scare fish into these intricate wooden traps.

Like all the best partnerships,

they have an equal share in the business.

TRANSLATION:

And because the dolphins get an easy meal,

they keep coming back for more.

It seems to be a fair deal all around.

River dolphins have evolved in the Amazon over 15 million years...

..and today they're adapting to the fastest change

this environment has ever seen.

But there's a deeper twist to this dolphin's tale,

and the remarkable relationship they've built

with their city-living neighbours.

Every single day, the dolphins head to Mocajuba,

whether there are fish on the menu or not.

It appears one of the main reasons they come...

..is to play.

These powerful predators could easily hurt the kids...

..but they never do, no matter what.

And the kids have grown up with dolphins as friends...

..and will always look out for them.

The bond the dolphins have formed with their new neighbours

seems unbreakable.

And while Amazon river dolphins elsewhere

are known to interact with humans,

this playful behaviour,

with no guarantee of reward,

is unique to the Mocajuba dolphins.

Most of us imagine cities to be concrete jungles devoid of nature...

..but, for some wildlife,

they're just a new habitat filled with new opportunities.

With the natural world shrinking

and our urban centres continuing to grow,

adapting to life in the city

has never been more important.

And if we're willing to accept wildlife as a neighbour,

and even to help animals get a foothold in the city,

the rewards can be huge,

for them and for us.

New York isn't an obvious place to film wildlife

but, as we'll discover in this series,

if you know where to look,

nature is all around us.

We usually think to make big discoveries, especially in biology,

that you have to travel someplace far away or someplace very remote,

but what's actually more true is that big discoveries

can happen almost anywhere at this point, so people

have literally discovered new species in New York City.

Biologist Clint Penick has spent four years studying New York's

pavement ants with the assistance of his pooter to wrangle them.

Have you ever sucked up anything unsavoury?

Oh, God! I hope not.

He's been called in to help cameraman Stuart

film this tiny city success story.

When I was told I was coming to New York for a film shoot,

this is definitely not what I had in mind.

THEY LAUGH

Yeah, I've filmed some pretty strange things in my days,

but this is definitely up there.

As weird as this looks, nobody's really batting an eyelid.

Yeah, you know, I almost never get stopped.

In the realm of things, someone sucking ants off the sidewalk

isn't that strange to a New Yorker for some reason.

There may be over 1.6 billion pavement ants living in New York

but, in terms of species, they're just a tip of the iceberg.

For a long time, people really thought of cities

as outside of nature,

and now we really recognise

that cities do have a lot of life

in them besides humans,

and that they are actually ecosystems in their own right.

From its pavements to its rooftops,

this city is brimming with wildlife.

It's now home to eight species of raptor alone,

including bald eagles,

red-tailed hawks,

and migratory ospreys.

New York City, as a biodiverse area, is incredibly species-rich.

Jason Smith is recording the city's wildlife

using state-of-the-art drones.

New York City is primarily a city of islands

so we end up with everything

from whales to butterflies

to snakes to leopard frogs.

There could literally be thousands upon thousands

of species living in New York City that we have no idea about.

It's so dynamic, it's incredible.

And nowhere is this more apparent than in the Bronx.

All right guys, so what do you think? What do you see?

Looks like we might have some shell over there...

That black one?

..but it also could have been rolling around in the sand. Ah.

Scientist Mark Weckel and his students

are tracking an elusive predator.

So this is the East River, Manhattan and Long Island.

Long Island is this super-large landmass

and it's also one of the last places in the United States

without a breeding population of coyotes.

But that may be changing.

Coyotes have been spotted in three of New York's five boroughs,

and the study's remote camera traps

have picked up some remarkable footage.

I've just seen wild coyotes in camera traps,

and they seem really, like, cool to see.

When you tell people, like, there's coyotes in New York City,

they're like, "Really? How are they able to survive here?"

Living on a diet including rats and other small mammals,

coyotes have been so successful here that since the sighting

of a single individual in 1995,

there are now thought to be as many as 30 living in the city.

Queens is the actual western tip of Long Island,

so we're literally standing

on the edge of coyote range expansion in New York State.

For the scientists working in New York, it's no surprise

that so many new and varied species are choosing to make the city home.

New York City is world renowned for being a cultural hub.

We have cultures from all across the world.

It only makes sense that the natural areas of New York City

are just as rich and biodiverse.

As more and more animals move into our cities,

their ultimate success may well depend on us.

Cities are the places where humans come into closest contact

with wildlife, and so we need to start thinking of cities

as an ecosystem.

So if we can think about this,

we can manage the wildlife in cities to kind of live

and cohabit with the species that that share our cities,

and that's because our own bond with nature really depends

on how we respond to urban wildlife.

We are not separate from nature.

Bees build hives, we build skyscrapers.

Beavers build dams, we build cabins in the woods.

We are not that far apart from each other.

The more we learn that this is all one experience...

..the easier it'll be for us all to get along in the long run.

Next time,

the world's wildlife is on the move...

..pioneering new migrations and facing new dangers...

..as they travel in and out of our cities

in search of their pot of gold.

They are becoming wild commuters.