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In the last 6,000 years

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the surface of our planet
has undergone a sudden change.

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A new habitat has appeared,

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entirely designed and constructed
by one species for its own purpose.

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This man-made landscape
may seem alien to animal life

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but for the bold, this is a world
of surprising opportunity.

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Jodhpur, India.

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A gang of bachelor male langurs

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has come to challenge
the resident alpha male.

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This alpha rules over
a valuable urban territory.

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But maintaining dominance here
is a constant struggle.

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The bachelors have united
to try and overthrow him.

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If they win, one of the challengers

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will take over
the alpha's troop of females,

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and may kill his infants.

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There are 15 males
in this bachelor group.

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The alpha must evict every single
one of them from his territory.

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He has chased half the bachelors away,

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but a splinter group has looped back
and is harassing his females.

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Once again, he has to battle.

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Finally, he manages to expel them all.

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He returns home victorious,

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but with a serious wound
on his right leg.

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It's a hard life for him in the city.

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Keeping the intruders away
is a daily challenge.

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But it's worth it.

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For these urban territories

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are probably the best
langur territories in the world.

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They're filled with
rich feeding grounds.

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Here in the temple gardens,

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the langurs have, over centuries,
developed a surprising relationship.

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One that guarantees them
a constantly replenished source of food.

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The people here associate langurs
with the Hindu God, Lord Hanuman,

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and revere them.

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They're given all the food they can eat.

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And this high-energy diet
has led to a baby

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Female langurs in this city

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give birth to twice as many young
as their forest counterparts.

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This mother is so well fed
that her rich milk

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can support something
rarely seen in the wild.

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Twins.

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And all these babies can create troops

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that are far larger than those
found in the forests nearby.

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With less time spent looking for food,
there is more time for play.

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The rewards of living in a city
can be huge.

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The challenge is to find your niche.

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But how to create a home in a world
that wasn't designed for wildlife?

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It's far brighter, louder and busier
than anywhere in the natural world.

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The continuous traffic creates barriers
to animal movement.

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And in this decade,
the urban environment

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Is predicted to grow by nearly 30%.

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What's more, to come here,

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animals have to compete
with the world's top predator.

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People makes the rules here.

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Four billion human beings
now live in the urban environment.

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It's here that animals have to contend
with the greatest change

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that is happening
to the face our planet.

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So why would any animal
want to come here?

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New York City.

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This densely built-up landscape
Is as unnatural as anywhere on Earth.

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And yet, this wild peregrine falcon
looks out onto an ideal habitat.

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Strange as it may seem,
this vastly-altered landscape

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replicates the conditions
in which peregrines evolved.

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The towering buildings
have a multitude of ledges

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on which falcons can nest,

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and the high perches that they need
to catch the wind.

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New York City has the highest density

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of nesting peregrines
anywhere on the planet.

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Winds striking the sides
of the skyscrapers

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are deflected upwards
and can help the birds gain height.

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And the great areas of concrete
roasting in the sun create thermals,

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so that, with very little effort,
the birds can soar over the city.

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And so many peregrines can live here,

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because down at street level
there is a lot of potential prey.

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Diving from height,
the falcons can reach speeds

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of over 300 kilometres an hour.

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But their prey stay down low
and close to the buildings.

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Too risky.

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The peregrine pulls out of his stoop.

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But the effort is not wasted.

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The falcons need to
flush their prey into the open.

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And Manhattan is surrounded by water.

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Out here the odds change.

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And in the peregrine's favour.

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With abundant prey here all year round,

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it has taken only 40 years

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for these falcons
to establish themselves here.

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And now, among skyscrapers,
they're more successful

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than their cousins
living in the wilderness.

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Mumbai, in India,
is home to over 20 million people.

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And there are predators here

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that, though rarely seen,
are rightly feared.

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Carnivores,

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lured by the prospect
of plentiful unsuspecting prey

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are on the prowl.

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A leopard.

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Every night, under the cover of darkness
they come out to hunt.

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These are big animals,

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and they're looking for large prey
to satisfy their hunger.

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To catch more than a glimpse of them
and reveal their hunting behaviour,

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you need night-vision cameras.

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Leopards have attacked
almost 200 people here

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in the last 25 years.

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But humans are not their usual prey.

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These leopards are on the hunt
for something else.

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Pigs.

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These leopards prefer to hunt
the domestic animals

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that people have brought to the city
in considerable numbers.

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The pigs keep their family close.

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The ceaseless noise of the city
plays to their advantage.

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It conceals their approach.

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And the leopards are using this cover
to hunt all over the city.

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This is a thriving population.

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In fact, the highest concentration
of leopards in the world

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is right here.

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It's not only the abundance of food
that attracts wild animals to cities.

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They're usually several degrees warmer
than the surrounding countryside.

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And here in Rome, in December,

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one animal is taking full advantage
of this extra heat.

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And it's leaving it's mark.

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In a single winter's day,

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ten tonnes of its droppings
rain down on the city.

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Starlings.

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In the evening, they come back
to the warmth of the city

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after feeding in
the neighbouring countryside.

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They must return
to their roosting trees.

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But the first to do so
are at the highest risk

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of being caught by birds of prey.

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So, they wait for others to arrive.

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There's safety in numbers.

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As daylight fades, the sky fills
with a staggering one million starlings.

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And then follows
one of nature's great spectaculars.

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How, or indeed why, they perform
these marvellous aerobatics,

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we still do not fully understand.

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Eventually, en masse,
they brave the descent

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and fill the branches
of their favourite trees.

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On these cold winter nights,
the city's extra warmth

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can mean the difference
between life and death.

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A city, of course, can provide

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not only shelter and abundant food,
but glamour.

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These varied objects
have been carefully chosen

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by a bird for their brightness
and their colour.

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This great bowerbird
has spent over a decade

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building this collection of
mostly man-made objects.

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Out on a golf course
in Townsville, Australia,

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he's putting the final touches
to his enormous bower,

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that he hopes will impress
a visiting female.

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He spends two hours each day
rearranging his prized objects.

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"Perhaps that would look
a little better over there.”

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But it seems that something is missing.

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Instead of going into town
to collect new objects,

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he's decided to raid
his neighbour's bower.

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"A clothes peg! Excellent!”

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"And a shiny toy car.”

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It's a risky game if you get caught.

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The owner is back.

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There is one bower
where the risk is worth it.

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A particular object has caught his eye.

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He'll have to wait
for the owner to leave.

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This is his chance.

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A real treasure.

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A scarlet heart.

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"Got it."

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The stage is now set
for female visitors.

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His luck may be in.

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The seduction can now begin.

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He's showing off his best goods.

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"Perhaps a little plastic piping?

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"Or maybe a bit of coloured string?”

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But his guest doesn't seem to be
paying much attention.

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"A fork?

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"Madame?"

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Nothing seems to be working.

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Something is just not quite right here.

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But he still has one trick
up his sleeve.

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The scarlet heart.

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As a final thrill
he expands the pink crest

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on the back of his head.

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The sign of his adulthood.

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But he's made a mistake.

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This is not a female

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but a young male who hasn't yet
developed that head crest.

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And he's making off
with the scarlet heart.

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It's not easy finding sex in the city.

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Raising a family in the city
is not easy either.

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It's spring time in Toronto,

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and this mother raccoon has exchanged
her native treetops for rooftops.

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Since giving birth two months ago,

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she's kept her offspring
safe and warm inside a chimney.

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Now, her young
have outgrown their nursery.

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This is her first major
challenge as a mother.

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The time has come to move to a new home.

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She needs to get her youngster
to ground level.

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But instead of an easy climb
down a tree,

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she is faced with a vertical drop,

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with little to cling onto.

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Her baby's first glimpse
of the urban world,

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from a terrifying ten metres up.

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This is the last of her litter
to be brought down.

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Its siblings are already

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busy exploring the area.

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And they have much to learn.

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This one has fallen into a back alley
and is trapped.

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Mother comes to the rescue
and demonstrates what must be done.

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That's the way.

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Raccoons are opportunists.

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And they're eager to explore.

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But they'll have to learn very quickly

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how to get along in this
strange new environment

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so full of hazards.

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Mother comes to the rescue once more.

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00:27:14,559 --> 00:27:17,679
Urban raccoons are now
demonstrably better

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at problem-solving
than their country cousins.

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When the feeding opportunities
are this good,

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the time spent working out
how to get to it

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is well worth it.

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The complexity of urban life

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favours the clever.

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But to compete with humanity
during daylight hours,

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takes more than just intelligence.

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It takes nerve.

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One enterprising species of monkey

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has moved into the city
of Jaipur in India.

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The Rhesus macaque.

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00:28:28,839 --> 00:28:32,599
But how to get a share
of all this juicy fruit?

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Every morning,
the troop make the same journey

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through the urban jungle,
Just as human commuters do.

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00:29:10,959 --> 00:29:14,679
Sometimes, inevitably,
there are traffic jams.

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Once they get to the market,
trouble begins.

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Being both intelligent and brazen

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Is the key to beating
human beings on their home turf.

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It's daylight robbery.

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There are some animals
that most would consider too dangerous

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to tolerate in the city.

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00:31:10,039 --> 00:31:11,399
Spotted hyenas.

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They're feared throughout their range.

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In the outskirts of Hara in Ethiopia,

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two clans are coming face to face
to battle over a prized resource.

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There are about 60 hyenas in each clan.

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And they're well matched.

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After three hours of
posturing back and forth,

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the losers retreat

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00:32:13,839 --> 00:32:16,559
and the victors head
to claim their prize.

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They have been fighting
over access to the city.

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00:32:40,599 --> 00:32:44,759
Once inside the city walls,
they head for one place.

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00:32:53,959 --> 00:32:56,559
And they know exactly how to get there.

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The ancient meat market.

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00:33:34,599 --> 00:33:38,639
The scent of all these carcasses
lies heavy in the air.

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This tradition goes back over 400 years.

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00:34:05,759 --> 00:34:08,999
The human butchers put out
the bones they don't need

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00:34:09,079 --> 00:34:11,799
and these hyenas deal with them.

252
00:34:14,519 --> 00:34:16,279
They're the only animals that can.

253
00:34:17,039 --> 00:34:21,119
No other here has such
powerful bone-crushing jaws.

254
00:34:24,599 --> 00:34:27,479
And this relationship
between man and beast

255
00:34:27,559 --> 00:34:29,759
has now been taken a step further.

256
00:34:33,399 --> 00:34:37,759
Yousuf is calling the hyenas
to his house.

257
00:34:45,919 --> 00:34:49,599
He and his forefathers,
going back five generations,

258
00:34:49,679 --> 00:34:51,719
have been feeding the hyenas

259
00:34:52,959 --> 00:34:54,199
by hand.

260
00:34:56,359 --> 00:34:59,599
The inhabitants of this town
believe that hyenas

261
00:34:59,679 --> 00:35:02,799
provide another very important service.

262
00:35:03,879 --> 00:35:07,719
Eating the bad spirits
that haunt the streets.

263
00:35:14,279 --> 00:35:17,479
These are wild and ferocious animals,

264
00:35:17,559 --> 00:35:19,959
but once within these city walls,

265
00:35:20,039 --> 00:35:22,999
they behave in a completely
different way.

266
00:35:24,999 --> 00:35:28,559
Throughout the rest of Africa,
spotted hyenas are feared

267
00:35:28,639 --> 00:35:31,759
because they kill livestock,
sometimes even children.

268
00:35:34,039 --> 00:35:37,879
They are perhaps the most
vilified animal on our planet.

269
00:35:42,399 --> 00:35:44,359
However, here in Harar,

270
00:35:44,439 --> 00:35:47,799
their relationship with people
is entirely peaceful.

271
00:35:50,919 --> 00:35:53,239
They have won the trust of man.

272
00:36:02,879 --> 00:36:04,879
Losing its fear of humans

273
00:36:04,959 --> 00:36:08,719
has enabled one animal
to spread into cities everywhere,

274
00:36:08,799 --> 00:36:10,639
and in huge numbers.

275
00:36:18,119 --> 00:36:22,719
Pigeons are by far
the most successful urban bird.

276
00:36:28,959 --> 00:36:31,359
Here, in Albi, in the south of France,

277
00:36:31,439 --> 00:36:33,639
the pigeons come to the river to bathe.

278
00:36:34,759 --> 00:36:37,439
They need to preen
their flight feathers,

279
00:36:37,519 --> 00:36:39,599
clean off the city dust,

280
00:36:40,239 --> 00:36:42,039
and cool themselves down.

281
00:37:02,839 --> 00:37:04,839
But death lies in wait.

282
00:37:07,279 --> 00:37:09,239
A predator that has taken advantage

283
00:37:09,319 --> 00:37:12,199
of the very thing that has led
to the pigeon's success...

284
00:37:14,759 --> 00:37:15,959
Their lack of fear.

285
00:37:19,479 --> 00:37:23,439
As the pigeons bathe,
oil from their plumage flows downstream,

286
00:37:23,959 --> 00:37:25,599
and is detected.

287
00:37:36,239 --> 00:37:39,239
A monstrous Wels catfish.

288
00:37:41,999 --> 00:37:46,999
Introduced here just 40 years ago,
they have proliferated.

289
00:37:48,719 --> 00:37:51,119
Virtually exterminated
the local fish stocks...

290
00:37:53,639 --> 00:37:57,199
And they've now developed a taste
for pigeon.

291
00:37:59,679 --> 00:38:01,399
Their eyesight is poor,

292
00:38:01,479 --> 00:38:05,479
so they use their barbels to sense
the movements of their victims.

293
00:39:01,159 --> 00:39:04,039
This is a radical new hunting strategy

294
00:39:04,119 --> 00:39:06,999
for what is normally
a bottom-dwelling fish.

295
00:39:22,079 --> 00:39:24,919
After a thousand years
of living in this city,

296
00:39:25,879 --> 00:39:29,879
pigeons are now having to learn
to avoid a fish.

297
00:39:35,959 --> 00:39:38,519
Our cities are always changing.

298
00:39:38,599 --> 00:39:40,279
Sometimes very swiftly.

299
00:39:42,959 --> 00:39:45,639
And animals must cope with the changes,

300
00:39:46,239 --> 00:39:47,679
or disappear.

301
00:39:49,639 --> 00:39:52,639
One of the greatest changes
in recent times

302
00:39:52,719 --> 00:39:57,599
has come from a single invention
made less than 140 years ago.

303
00:40:02,479 --> 00:40:03,959
Electric light.

304
00:40:06,159 --> 00:40:08,679
It has become more and more powerful,

305
00:40:11,039 --> 00:40:13,079
filling our streets with light.

306
00:40:24,759 --> 00:40:26,639
It's everywhere in the city.

307
00:40:28,719 --> 00:40:30,319
It even goes underground.

308
00:40:49,719 --> 00:40:54,639
The difference between day and night
Is becoming less and less perceptible.

309
00:41:04,239 --> 00:41:08,759
And that has a profound effect
on the activities of wildlife.

310
00:41:13,839 --> 00:41:18,319
In the wilderness,
light triggers all kinds of behaviour.

311
00:41:24,279 --> 00:41:25,999
On the night of the full moon,

312
00:41:26,079 --> 00:41:28,999
hundreds of tiny
hawksbill turtle hatchlings

313
00:41:29,079 --> 00:41:32,959
emerge from the safety of their nest
deep in the sand.

314
00:41:35,399 --> 00:41:39,279
Their instinct is to reach the sea
as quickly as possible.

315
00:41:41,399 --> 00:41:46,199
And their guide is the light
of the full moon reflected on the water.

316
00:41:53,279 --> 00:41:57,159
But this young hatchling is confused.

317
00:42:05,439 --> 00:42:08,159
It's going in the wrong direction.

318
00:42:13,199 --> 00:42:15,719
Bright light is coming from the land.

319
00:42:18,759 --> 00:42:23,399
And all these hatchlings
are travelling up the beach towards it.

320
00:42:29,279 --> 00:42:32,239
Predators are ready to take advantage.

321
00:42:34,119 --> 00:42:38,119
Crabs now make their burrows
directly beneath the beach lights

322
00:42:38,799 --> 00:42:41,719
and wait for their prey to come to them.

323
00:43:03,439 --> 00:43:05,919
Even if a hatchling escapes,

324
00:43:06,559 --> 00:43:07,959
they're still in peril.

325
00:43:16,719 --> 00:43:19,799
The lights become
more and more bewildering.

326
00:43:43,879 --> 00:43:46,999
80% of all hatchlings on this beach

327
00:43:47,079 --> 00:43:51,039
are now disorientated
by the lights of the town.

328
00:44:11,119 --> 00:44:13,879
Roads bring many to their end.

329
00:44:28,839 --> 00:44:32,639
Hundreds get trapped
in storm drains every night.

330
00:44:46,999 --> 00:44:50,679
Exhausted by the effort of travelling
such a distance on land,

331
00:44:53,159 --> 00:44:57,279
this hatchling's chances
of surviving the night are slim.

332
00:45:09,959 --> 00:45:13,079
This turtle is one of
the countless species

333
00:45:13,159 --> 00:45:15,879
that have been unable
to adapt to the change

334
00:45:15,959 --> 00:45:18,959
brought about by the urban environment.

335
00:45:30,519 --> 00:45:32,639
Only a small number of animals

336
00:45:32,719 --> 00:45:35,919
have managed to find ways
of living alongside us.

337
00:45:38,239 --> 00:45:42,239
And every ten years,
an area the size of Britain

338
00:45:42,319 --> 00:45:45,439
disappears under a jungle of concrete.

339
00:45:54,799 --> 00:45:57,639
But it doesn't have to be like this.

340
00:46:00,679 --> 00:46:05,319
Could it not be possible to build cities
more in harmony with nature?

341
00:46:12,759 --> 00:46:18,839
How, and whether we decide to invite
the wildlife back, is up to us.

342
00:46:22,759 --> 00:46:25,919
This tree is rising nearly 30 storeys.

343
00:46:25,999 --> 00:46:31,919
It's one of almost 800 being planted
to create a vertical forest in Milan.

344
00:46:37,919 --> 00:46:42,199
This number of living trees would
normally fill two hectares of woodland,

345
00:46:42,279 --> 00:46:46,079
but here, they occupy
one-tenth of that area.

346
00:46:47,599 --> 00:46:50,559
Greening the walls
and roofs of our buildings

347
00:46:50,639 --> 00:46:53,199
could create
a rich and extensive habitat

348
00:46:53,279 --> 00:46:55,199
if we wanted it to do so.

349
00:46:58,359 --> 00:47:03,119
There is one city where that idea
is being applied on a major scale.

350
00:47:03,879 --> 00:47:04,999
Singapore.

351
00:47:06,959 --> 00:47:11,759
Two million trees have been planted here
in the last 45 years.

352
00:47:13,399 --> 00:47:17,959
This city is now richer in species
than any other in the world.

353
00:47:25,159 --> 00:47:28,799
And this practice extends
to all parts of the city.

354
00:47:30,279 --> 00:47:32,039
The waterways have been cleaned up,

355
00:47:32,119 --> 00:47:34,719
and smooth-coated otters
are coming back.

356
00:47:41,119 --> 00:47:45,439
But perhaps the most spectacular
example of city greening

357
00:47:45,519 --> 00:47:48,839
Is this grove of super trees.

358
00:47:51,879 --> 00:47:57,879
These 50-metre high metal structures
are now full of life.

359
00:47:59,679 --> 00:48:03,559
Creepers have been planted
to grow over the outermost branches.

360
00:48:07,919 --> 00:48:11,119
Is this a vision
of our cities of the future?

361
00:48:15,119 --> 00:48:18,479
The potential to see animals
thriving within our cities

362
00:48:18,559 --> 00:48:21,679
Is achievable across the globe.

363
00:48:30,159 --> 00:48:34,399
More than half of us now live in
an urban environment.

364
00:48:36,719 --> 00:48:39,999
Whether we choose
to create a home for others too

365
00:48:41,439 --> 00:48:43,119
is up to us.