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There is only one planet
in the universe, as far as we know,
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where there is life.
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The Earth.
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Our home.
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The perfect planet.
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Life here is only possible
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00:00:55,524 --> 00:00:59,844
because of a unique balance
of natural forces.
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00:01:04,245 --> 00:01:08,685
Energy from the sun
powers the living world.
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Weather systems transport fresh
water around the globe.
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And powerful ocean currents
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circulate life's essential
nutrients.
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This series will reveal how these
global forces have worked together
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to create our planet's
fragile life-support system.
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One of these forces is so important
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that life would never have
even started without it.
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Across the surface of our planet,
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there are over 1,500 active
volcanoes.
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This is the most active -
Kilauea in Hawaii.
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Here, magma - liquid rock
from the planet's hot interior -
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00:02:59,844 --> 00:03:03,621
bursts out through fractures
in the Earth's crust,
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and it's been flowing for months.
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Nothing can stand in the lava's way.
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Volcanoes are certainly destructive.
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But without these powerful
underground forces,
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there would be no breathable
atmosphere.
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No oceans.
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No land.
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No life.
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We can't control volcanoes,
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but they're vital for all living
things on Planet Earth.
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This is Ol Doinyo Lengai
in Tanzania.
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It's one of Africa's
most active volcanoes,
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and has erupted over 15 times
in the last 100 years.
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On its northern flank lies
Lake Natron,
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400 square miles in extent,
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and one of the world's most
corrosive bodies of water.
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The water wells up from deep below,
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carrying such a concentration of
chemicals that it can burn skin.
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But one animal thrives here.
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Volcano birds.
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Nearly two million lesser flamingos
live in East Africa
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and all of them come here to breed.
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But they can only nest here
when the lake's level
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drops so far that in the centre,
its bed is exposed.
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And that rare moment is now.
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How they know when the conditions
are right is a mystery,
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but some have flown thousands
of miles to be here.
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The flamingos head for the
middle of the lake,
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where the intense evaporation
has created islands of salt.
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It's here that the birds
build their nests,
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over three miles from the
lake's edge
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and safe from land predators,
which are unable to cross
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the surrounding moat of
caustic soda.
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The single egg is laid on a mount
of hardened salt
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built by the adults,
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its height an insurance against
a sudden rise in water level...
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which often happens on
Lake Natron.
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As the centre dries and enlarges,
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more and more flamingos arrive
to nest on it.
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In good years, such as now,
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as many as half a million pairs
breed here.
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After 28 days of incubation,
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a chick emerges into Natron's
harsh glare.
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Here, temperatures can rise
to 55 degrees Celsius.
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Mother's wing, however,
can serve as a sun shield.
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The chick is fed a rich liquid
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made of the lake's
barely digested algae
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and traces of its parent's blood.
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After a few days, the chick is
strong enough to stretch its legs.
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It then joins a growing creche,
made up of chicks of different ages.
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Soon, the need for fresh water
will force the infant birds
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to trek to springs on the
lake's edge.
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A journey they have to make on foot,
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as their flight feathers
have yet to develop.
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Every day, the adults fly
to these springs to feed.
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Here, on the lake's margins,
they collect algae that flourish
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in the volcanic water -
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vital food for the flamingos.
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It's the algae that turn
the flamingos' feathers pink.
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It even colours their eyes.
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The adults spend most of their day
at the springs,
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and now their chicks
are going to join them there.
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No-one wants to get left behind.
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It's a three-mile march
over razor-sharp flakes of soda
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and sticky, caustic mud.
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A life-threatening trial,
especially for the youngest chicks.
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The groups merge into one
giant creche.
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For some, the challenges
are just too great.
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Exhaustion overcomes the weakest.
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And now, there is yet
another threat.
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Marabou storks.
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They have long legs like a flamingo,
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but a beak like a Roman sword.
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And they are patient,
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waiting for an easy target.
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Their very presence creates panic
among the chicks.
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The smallest avoid
being trampled underfoot
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by travelling on the outside
of the group.
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But that exposes them to attack.
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Their only defence is to run.
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But you have little chance
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when you're barely ankle-high
to your pursuer.
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00:13:03,965 --> 00:13:06,924
Stragglers will almost
certainly be taken.
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00:13:10,044 --> 00:13:14,524
But there comes a point
when every stork has had its fill.
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This little chick is very lucky.
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At last, the youngsters reach
the freshwater springs
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at the lake's margin
to rejoin their parents.
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Almost unbelievably,
each chick has a unique call
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that its parent can recognise.
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Ultimately, so do all living things.
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Over 80% of the Earth's surface
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is the result of magma bursting up
from the molten interior.
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The process started
four billion years ago
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and it still continues today.
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00:15:02,764 --> 00:15:07,221
When lava cools, it solidifies
into rock,
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and eventually weathers into land
that can support life.
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All the Galapagos Islands
in the Pacific are volcanic,
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and Fernandina is the
youngest of them.
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And still growing.
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At its centre, a volcanic crater
four miles wide...
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and over 800 metres deep.
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It seems dormant, but it was
erupting only two weeks ago.
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00:16:06,965 --> 00:16:12,205
Even so, there are some who depend
on the heat from this volcano.
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00:16:18,125 --> 00:16:23,164
A female land iguana, heavy with
eggs, approaches the crater's rim.
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00:16:26,044 --> 00:16:29,421
It took her ten days
to climb up here,
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00:16:29,445 --> 00:16:32,924
but the toughest part of her
journey is still ahead.
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She's going to descend
into the crater itself.
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Frequent tremors
make the crater walls unstable.
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More people have travelled in space
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than have visited the bottom
of Fernandina's crater.
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But instinct drives her on.
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The warm volcanic ash on
the crater floor
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has the perfect temperature
for incubating her eggs.
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But there are no clear paths down.
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Any made last year have been
destroyed by rock falls.
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The slope is steep and unstable.
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00:18:02,125 --> 00:18:05,404
Tumbling rocks
quickly become an avalanche.
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With the boulders falling down
away from her,
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she's not in immediate danger.
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00:18:27,125 --> 00:18:30,300
But behind her, higher up,
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two other females
have also started the descent.
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And now she is in the firing line.
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She's safe.
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00:19:14,845 --> 00:19:17,444
Others before her
haven't been so lucky.
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But she's undeterred.
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At last, after an eight-hour
descent,
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she reaches the crater floor.
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00:20:00,164 --> 00:20:04,045
Now she must find a suitable
place to dig her nest.
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The best sites are already taken.
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00:20:19,404 --> 00:20:22,845
And nesting females are very
aggressive.
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A nodding head means keep away.
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Push off!
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Ignored warnings are met with force.
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But she's come a long way,
and she's not going to give up now.
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She, too, starts to dig a hole
in which to lay her eggs.
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That done, she will head back,
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leaving the volcano to provide
the warmth her eggs need
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if they are to hatch.
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Sometimes, of course,
the volcano erupts
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and destroys not only eggs
but many nesting adults.
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But for the iguanas,
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the benefits of nesting in
the crater are so great
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that it's worth all the risks.
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00:22:04,765 --> 00:22:10,340
Volcanic islands make up just 5%
of the planet's land,
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but they're home
to nearly 20% of its species.
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00:22:17,845 --> 00:22:22,101
Animals often evolve very
swiftly on islands,
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cut off from their mainland
relatives
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and faced with the challenges
of isolation.
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This is Wolf, an extinct volcano
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and one of the most remote islands
of the Galapagos,
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800 miles from
the nearest large landmass
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and over a million years old.
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A finch.
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A female.
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Its ancestors doubtless were blown
here by storms many centuries ago.
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Like most finches, they feed on
seeds, nectar and insects.
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00:23:07,845 --> 00:23:11,005
But there's little food
of any kind on Wolf.
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And since they aren't strong enough
fliers to leave the island,
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they've had to find food
from a very unusual source.
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They depend on another
of the island's inhabitants.
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Nazca boobies.
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Every day, these sea birds commute
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00:23:44,644 --> 00:23:48,204
between the island and their fishing
grounds out in the open ocean.
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Each time a pair meet,
they renew their bond.
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00:23:58,125 --> 00:24:01,525
And then catch up with the
neighbours.
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Now is the time...
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to hop into action.
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Blood.
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They are vampire finches.
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00:24:46,005 --> 00:24:51,164
These little birds have become
one of the world's newest species.
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She cuts the quill
of a large flight feather,
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and the blood flows.
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The sight of it attracts the
attention of others.
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Blood is very nutritious -
worth fighting for.
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So with this never-ending supply
of food,
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00:25:35,525 --> 00:25:38,340
the vampire finches
can flourish on an island
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00:25:38,365 --> 00:25:41,365
where otherwise they could
not survive.
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00:25:46,684 --> 00:25:50,884
Why the boobies don't object,
nobody knows.
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00:25:54,125 --> 00:25:56,980
Perhaps the finches' behaviour
started
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00:25:57,005 --> 00:26:00,884
when they helped the boobies to
remove parasites from their plumage.
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00:26:03,765 --> 00:26:06,701
Maybe the boobies
think that the little vampires
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00:26:06,724 --> 00:26:09,141
are still providing a service.
203
00:26:09,164 --> 00:26:10,724
Who can tell?
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00:26:16,325 --> 00:26:19,980
Volcanic islands don't last forever.
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00:26:20,005 --> 00:26:25,260
Changes deep in the Earth's crust
bring their eruptions to an end
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00:26:25,285 --> 00:26:28,884
and the forces of erosion
then begin to wear them down.
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00:26:38,285 --> 00:26:41,500
But the coral around them
continues to grow,
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00:26:41,525 --> 00:26:45,500
sea levels change,
and eventually all that is left
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00:26:45,525 --> 00:26:51,421
is a ring-shaped island of coral
rock surrounding a lagoon.
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An atoll.
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00:27:03,484 --> 00:27:07,060
There are hundreds of atolls
in tropical seas,
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all remnants of vanished volcanoes.
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00:27:17,484 --> 00:27:20,381
This is one of the largest
and most pristine -
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00:27:20,404 --> 00:27:23,444
Aldabra, in the Indian Ocean.
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00:27:26,204 --> 00:27:29,540
20 million years ago,
it was an island
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with a volcanic crater in
its centre.
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00:27:37,565 --> 00:27:39,684
Now, it's an atoll.
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00:27:41,164 --> 00:27:45,164
Mangroves took root
and sea birds came to nest.
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00:27:47,964 --> 00:27:50,941
One land animal in particular...
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00:27:50,964 --> 00:27:53,005
..reached here before man.
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00:27:56,444 --> 00:27:58,285
A giant tortoise.
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00:27:59,605 --> 00:28:01,701
These creatures can float
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00:28:01,724 --> 00:28:06,204
and live without food or fresh water
for long periods of time.
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00:28:10,484 --> 00:28:14,125
This isolated atoll is the
perfect refuge.
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00:28:15,164 --> 00:28:17,684
Their only enemy is the sun.
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00:28:23,484 --> 00:28:28,565
Without shade, a tortoise risks
being boiled in his shell.
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00:28:33,045 --> 00:28:36,461
So, after feeding
in the cool of the morning,
228
00:28:36,484 --> 00:28:39,500
and before the sun
becomes too crushingly hot,
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00:28:39,525 --> 00:28:41,325
they have to find cover.
230
00:28:42,765 --> 00:28:44,005
All of them.
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00:28:50,325 --> 00:28:54,820
There is very little vegetation,
but caves in the coral rock
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00:28:54,845 --> 00:28:57,404
can provide the shade
they so badly need.
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00:29:05,484 --> 00:29:08,181
He's nearly there.
234
00:29:08,204 --> 00:29:13,244
All that is left is a white-knuckle
ride to the bottom.
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00:29:16,964 --> 00:29:18,924
And he's in.
236
00:29:22,684 --> 00:29:25,204
Thousands of others
are still out in the sun.
237
00:29:26,845 --> 00:29:31,525
This tree could shade a couple
of hundred, if they pack tight.
238
00:29:46,765 --> 00:29:48,765
It's bumper-to-bumper parking.
239
00:29:54,765 --> 00:29:58,701
Within an hour or so,
all must find shade of some sort
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00:29:58,724 --> 00:30:00,525
if they're to survive.
241
00:30:34,085 --> 00:30:35,684
Safe.
242
00:30:37,884 --> 00:30:42,724
But the future for Aldabra's
tortoises is far from certain.
243
00:30:44,285 --> 00:30:48,500
The climate is changing,
sea levels are rising,
244
00:30:48,525 --> 00:30:53,181
and Aldabra's tortoises may soon
have to find a new refuge,
245
00:30:53,204 --> 00:30:55,085
or drown.
246
00:31:01,525 --> 00:31:05,780
In some places, volcanoes erupt
not in the ocean
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00:31:05,805 --> 00:31:08,805
but in the very middle
of a continent.
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00:31:12,684 --> 00:31:14,701
North America.
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00:31:14,724 --> 00:31:19,565
And in its very heart,
a volcanic hot spot - Yellowstone.
250
00:31:26,765 --> 00:31:29,340
The last major eruption here
251
00:31:29,365 --> 00:31:34,260
came to an end about
650,000 years ago,
252
00:31:34,285 --> 00:31:37,845
but this volcano is only sleeping.
253
00:31:39,724 --> 00:31:43,125
Not far below ground,
there is still magma.
254
00:31:44,605 --> 00:31:48,085
And that heats the ground water
to boiling point.
255
00:31:53,005 --> 00:31:54,924
Geysers.
256
00:31:58,005 --> 00:32:03,765
Some spout boiling water and steam
to heights of 90 metres or so.
257
00:32:05,724 --> 00:32:10,540
Elsewhere, the scalding waters
liquefy the ground sediments,
258
00:32:10,565 --> 00:32:13,484
creating pots of boiling mud.
259
00:32:19,444 --> 00:32:25,164
And this underground heating
has proved a lifeline for some.
260
00:32:31,365 --> 00:32:33,125
River otters.
261
00:32:37,005 --> 00:32:40,580
They need a constant supply of food
if they're to keep warm
262
00:32:40,605 --> 00:32:43,285
in these freezing temperatures.
263
00:32:47,724 --> 00:32:52,005
And this close-knit family
know exactly where to find it.
264
00:33:09,285 --> 00:33:13,141
The springs are so hot that the
rivers never freeze,
265
00:33:13,164 --> 00:33:15,365
even in the coldest winters.
266
00:33:20,484 --> 00:33:24,325
So the otter family can fish
the year round.
267
00:33:43,565 --> 00:33:45,365
Trouble.
268
00:33:47,525 --> 00:33:50,260
This coyote knows that
in the middle of winter,
269
00:33:50,285 --> 00:33:53,740
a thermal river means otters,
270
00:33:53,765 --> 00:33:56,404
and otters mean fish.
271
00:34:01,525 --> 00:34:05,325
The question is
how to steal their catch.
272
00:34:29,445 --> 00:34:33,204
Perhaps the thing to do is to
pretend you're not interested...
273
00:34:34,804 --> 00:34:39,605
..and hope that they wander close
enough for a snatch-and-run raid.
274
00:34:51,804 --> 00:34:54,581
It seems the cool-under-fire otters
275
00:34:54,605 --> 00:34:58,164
can outwit the not-so-wily coyote.
276
00:35:09,565 --> 00:35:12,541
Many animals benefit
from the volcanic heat
277
00:35:12,565 --> 00:35:14,885
coming up from below.
278
00:35:17,644 --> 00:35:22,965
And we do as well, but not nearly
as much as we could.
279
00:35:25,764 --> 00:35:28,380
The volcanic heat could provide us
280
00:35:28,405 --> 00:35:31,021
with much of the energy
that we need,
281
00:35:31,045 --> 00:35:34,101
and then we could stop
burning gas and coal
282
00:35:34,125 --> 00:35:37,565
that is now changing the
climate worldwide.
283
00:35:48,565 --> 00:35:50,581
Deep in the Earth's crust,
284
00:35:50,605 --> 00:35:53,420
below both the oceans
and the continents,
285
00:35:53,445 --> 00:35:57,885
there are lines of weakness
along which rises liquid rock.
286
00:36:02,885 --> 00:36:07,181
The Kamchatka Peninsula
in the north-west Pacific
287
00:36:07,204 --> 00:36:09,204
lies along one of them.
288
00:36:23,684 --> 00:36:27,340
There are only a thousand known
geysers in the world,
289
00:36:27,364 --> 00:36:31,525
and many of them are here
in this isolated valley.
290
00:36:43,965 --> 00:36:47,644
Steam from superheated water
fills the air.
291
00:36:48,965 --> 00:36:53,101
But the danger from the scalding
pools does little to deter
292
00:36:53,125 --> 00:36:56,364
Kamchatka's most famous residents.
293
00:37:05,164 --> 00:37:09,780
In May, when the rest of Kamchatka
is still covered by snow,
294
00:37:09,804 --> 00:37:11,541
this valley is free of it,
295
00:37:11,565 --> 00:37:16,485
and bears, having just woken up from
their winter sleep, know that.
296
00:37:23,764 --> 00:37:27,260
The grass is fertilised
by mineral-rich water
297
00:37:27,284 --> 00:37:29,125
spraying from the geysers.
298
00:37:31,764 --> 00:37:34,981
Much-needed forage for
a large male bear
299
00:37:35,005 --> 00:37:38,005
that hasn't eaten for
several months.
300
00:37:43,525 --> 00:37:45,925
And he's not the only one.
301
00:37:57,085 --> 00:38:00,581
The bears haven't seen one another
for seven months,
302
00:38:00,605 --> 00:38:02,405
since the start of winter.
303
00:38:05,045 --> 00:38:09,284
And it seems that right now, they
would prefer to keep it that way.
304
00:38:10,925 --> 00:38:15,565
Nothing should come between a bear
and his first meal of the year.
305
00:38:20,684 --> 00:38:23,820
And in one place,
Kamchatka's underground forces
306
00:38:23,844 --> 00:38:27,364
provide its bears
with even more nutritious meals.
307
00:38:35,324 --> 00:38:39,260
Kurile Lake lies within the crater
of an immense volcano
308
00:38:39,284 --> 00:38:42,780
that long ago produced one of the
greatest eruptions
309
00:38:42,804 --> 00:38:44,605
in the planet's history.
310
00:38:48,085 --> 00:38:51,324
The lake is still circled
by active vents...
311
00:38:53,684 --> 00:38:57,420
..and mineral-rich ash
from their regular eruptions
312
00:38:57,445 --> 00:39:00,485
has made these waters
particularly fertile.
313
00:39:03,804 --> 00:39:07,181
Millions of salmon come
here from the Pacific Ocean
314
00:39:07,204 --> 00:39:10,061
in order to spawn in
these fertile waters,
315
00:39:10,085 --> 00:39:13,885
which will provide their newly
hatched young with abundant food.
316
00:39:20,204 --> 00:39:25,885
So, grass soon ceases to be top
of the menu for Kamchatka's bears.
317
00:39:29,164 --> 00:39:31,780
By the time spring
has turned to summer,
318
00:39:31,804 --> 00:39:36,221
Kurile Lake contains the
most dense assembly of bears
319
00:39:36,244 --> 00:39:39,085
to be found anywhere on Earth.
320
00:39:44,324 --> 00:39:46,724
All hungry for salmon.
321
00:39:57,605 --> 00:40:02,684
But this early in the season,
the fish are still strong and swift.
322
00:40:18,724 --> 00:40:20,925
Nothing seems to work.
323
00:40:29,085 --> 00:40:32,380
But one old bear knows that,
right now,
324
00:40:32,405 --> 00:40:34,925
there is an easier meal to be had.
325
00:40:38,764 --> 00:40:42,141
He remembers that if he
paddles out into the lake,
326
00:40:42,164 --> 00:40:45,501
away from the shoals
of newly arrived salmon,
327
00:40:45,525 --> 00:40:48,965
there's food that
doesn't need chasing.
328
00:41:08,125 --> 00:41:11,300
Some of the first fish
to arrive have died,
329
00:41:11,324 --> 00:41:13,565
and their bodies can
be easily collected...
330
00:41:14,965 --> 00:41:16,764
..from the bottom of the lake.
331
00:41:22,925 --> 00:41:27,965
Diving for them at leisure
doesn't use many calories.
332
00:41:33,045 --> 00:41:35,844
And he can take his time.
333
00:41:48,485 --> 00:41:50,501
A couple of weeks later,
334
00:41:50,525 --> 00:41:54,164
the salmon are beginning
to spawn and are less wary.
335
00:41:56,804 --> 00:41:59,644
Now it's worth running.
336
00:42:16,284 --> 00:42:18,525
The fish are so abundant...
337
00:42:20,605 --> 00:42:22,565
..that there is plenty for all...
338
00:42:24,445 --> 00:42:27,244
..even those with no
previous experience.
339
00:42:31,324 --> 00:42:33,621
There are now so many fish,
340
00:42:33,644 --> 00:42:37,125
it's difficult to know
which one to chase.
341
00:42:52,284 --> 00:42:57,701
In a single day, a bear can
consume 100,000 calories,
342
00:42:57,724 --> 00:43:01,364
50 times more than the
average human being does.
343
00:43:02,804 --> 00:43:06,844
And one part is
particularly delicious...
344
00:43:10,965 --> 00:43:12,780
..caviar.
345
00:43:12,804 --> 00:43:15,605
80 calories in every mouthful.
346
00:43:23,605 --> 00:43:27,420
By supporting huge
concentrations of salmon,
347
00:43:27,445 --> 00:43:31,340
mineral ash from
Kurile Lake's volcanoes
348
00:43:31,364 --> 00:43:35,085
has made life surprisingly
easy for these bears.
349
00:43:49,125 --> 00:43:53,460
Our planet depends on minerals
brought up by volcanoes
350
00:43:53,485 --> 00:43:55,804
from the Earth's molten core.
351
00:43:59,324 --> 00:44:04,364
A single ash cloud can carry
billions of tonnes of minerals.
352
00:44:18,005 --> 00:44:21,820
And as a consequence,
the lands surrounding volcanoes
353
00:44:21,844 --> 00:44:24,244
are among the world's most fertile.
354
00:44:29,724 --> 00:44:32,501
Those in East Africa's Rift Valley
355
00:44:32,525 --> 00:44:36,244
support the most dynamic
ecosystem on Earth.
356
00:44:41,684 --> 00:44:43,525
The Serengeti.
357
00:44:47,804 --> 00:44:52,844
This is the most productive of
all natural grasslands anywhere.
358
00:44:54,965 --> 00:44:57,621
Every year, over a
million wildebeest
359
00:44:57,644 --> 00:45:01,181
assemble in this particular
corner of the Serengeti
360
00:45:01,204 --> 00:45:06,740
to feed on grass especially
rich in calcium and phosphorus,
361
00:45:06,764 --> 00:45:10,364
essential minerals
for the pregnant females.
362
00:45:12,885 --> 00:45:16,661
In just three weeks,
half a million calves are born
363
00:45:16,684 --> 00:45:19,445
on these ash-rich plains.
364
00:45:21,565 --> 00:45:25,021
That's 24,000 a day...
365
00:45:25,045 --> 00:45:27,644
..a thousand an hour.
366
00:45:31,405 --> 00:45:34,764
Calves stand up within a
few minutes of being born.
367
00:45:38,525 --> 00:45:42,485
Though some need a little
more time to find their feet.
368
00:45:54,885 --> 00:45:57,300
But a mother won't
let her calf suckle
369
00:45:57,324 --> 00:46:00,764
until it's mastered
a few physical skills...
370
00:46:03,724 --> 00:46:05,405
..walking...
371
00:46:06,445 --> 00:46:07,764
..trotting...
372
00:46:09,684 --> 00:46:11,445
..and running.
373
00:46:21,045 --> 00:46:25,724
Wildebeest calves must run
if they're to stay alive.
374
00:46:41,005 --> 00:46:43,780
For these plains also support
375
00:46:43,804 --> 00:46:48,364
the greatest assembly
of hunters on the planet.
376
00:46:51,565 --> 00:46:55,005
Each species has its own
special hunting technique.
377
00:46:56,284 --> 00:46:58,525
But all have the same aim...
378
00:47:01,204 --> 00:47:06,164
..to make the most of this
brief super-abundance of life.
379
00:48:04,445 --> 00:48:11,181
Only one in ten wildebeest
calves will survive to adulthood.
380
00:48:11,204 --> 00:48:15,684
But that is enough to maintain the
million-strong herd of wildebeest...
381
00:48:17,684 --> 00:48:21,125
AND the planet's highest
density of predators.
382
00:48:24,525 --> 00:48:27,260
Volcanoes fertilise the planet,
383
00:48:27,284 --> 00:48:30,460
but they're the source of
something else so important
384
00:48:30,485 --> 00:48:33,684
that life could not
have started without it.
385
00:48:38,605 --> 00:48:42,501
The first carbon dioxide
in the Earth's atmosphere
386
00:48:42,525 --> 00:48:47,005
was brought by volcanoes
from deep in the Earth's crust.
387
00:48:50,605 --> 00:48:54,621
And this gas is the
foundation of life.
388
00:48:54,644 --> 00:48:57,420
Every plant needs it to grow,
389
00:48:57,445 --> 00:48:59,925
and absorbs it from the air.
390
00:49:03,005 --> 00:49:06,780
Volcanoes continue to
release carbon dioxide today,
391
00:49:06,804 --> 00:49:09,581
and for the last 10,000 years,
392
00:49:09,605 --> 00:49:14,485
its presence in the atmosphere
has suited life perfectly.
393
00:49:17,364 --> 00:49:20,021
Its greenhouse properties have kept
394
00:49:20,045 --> 00:49:23,244
our planet's climate
stable and warm.
395
00:49:30,284 --> 00:49:33,900
But too much carbon dioxide would
make the planet's temperature
396
00:49:33,925 --> 00:49:36,541
rise to levels that
would upset the Earth's
397
00:49:36,565 --> 00:49:40,764
long-established
ecological balances.
398
00:49:56,045 --> 00:49:58,621
Today, humanity itself
399
00:49:58,644 --> 00:50:02,485
has become a new
kind of supervolcano.
400
00:50:09,005 --> 00:50:14,061
Now, every year, we ourselves
release 100 times more carbon
401
00:50:14,085 --> 00:50:17,005
than all the Earth's
volcanoes combined.
402
00:50:18,525 --> 00:50:21,965
And that has brought climate chaos.
403
00:50:26,324 --> 00:50:29,300
We can't control volcanoes,
404
00:50:29,324 --> 00:50:34,405
but we can limit the amount of
carbon dioxide that we produce.
405
00:50:35,885 --> 00:50:38,940
And if we do that,
there will still be time
406
00:50:38,965 --> 00:50:41,900
to restore the ecological balance
407
00:50:41,925 --> 00:50:46,045
that once made this Earth
our perfect planet.
408
00:50:58,164 --> 00:51:00,181
Lake Natron, in Tanzania
409
00:51:00,204 --> 00:51:04,661
is one of the world's
most toxic bodies of water.
410
00:51:04,684 --> 00:51:08,300
Yet once every few years,
when the centre dries out,
411
00:51:08,324 --> 00:51:12,684
it's brought to life by
thousands of breeding flamingos.
412
00:51:16,605 --> 00:51:18,541
But to reach the colony,
413
00:51:18,565 --> 00:51:21,885
there's only one way to
cross this soft soda sludge.
414
00:51:24,284 --> 00:51:26,420
It's finally here.
415
00:51:26,445 --> 00:51:28,300
Our secret weapon...
416
00:51:28,324 --> 00:51:30,844
..is a hovercraft.
417
00:51:32,045 --> 00:51:34,260
And it's beautiful.
418
00:51:34,284 --> 00:51:36,221
Having shipped it from the UK,
419
00:51:36,244 --> 00:51:39,764
Darren's keen to test
that all systems are go.
420
00:51:42,684 --> 00:51:45,300
Getting it off the
trailer is one thing,
421
00:51:45,324 --> 00:51:48,021
but at least the hovercraft's fans,
that give it lift,
422
00:51:48,045 --> 00:51:50,005
are working well enough.
423
00:52:05,565 --> 00:52:07,621
Well, guys, what do you think?
424
00:52:07,644 --> 00:52:10,420
We know she works, but...
425
00:52:10,445 --> 00:52:13,260
..maybe some of these
guys' lungs don't now.
426
00:52:13,284 --> 00:52:17,820
125 miles away,
on the edge of Lake Natron,
427
00:52:17,844 --> 00:52:21,644
cameraman Matt Aeberhard is
trying to camouflage his hides.
428
00:52:23,085 --> 00:52:25,101
Those are our blinds.
429
00:52:25,125 --> 00:52:27,541
So, you can't camouflage
those on the flats,
430
00:52:27,565 --> 00:52:29,981
and the best thing that
we can do is actually
431
00:52:30,005 --> 00:52:32,164
turn them into a little
cluster of flamingos.
432
00:52:38,125 --> 00:52:40,541
It's pretty cool, huh?
433
00:52:40,565 --> 00:52:45,780
Hide complete, all that's needed
is transport out to the colony.
434
00:52:45,804 --> 00:52:48,541
And after a ten-hour
cross-country journey,
435
00:52:48,565 --> 00:52:51,661
Darren arrives with
his secret weapon...
436
00:52:51,684 --> 00:52:54,621
..and it's an instant hit.
437
00:52:54,644 --> 00:52:56,565
It's the new local
tourist attraction.
438
00:52:58,005 --> 00:53:00,221
You like it?
439
00:53:00,244 --> 00:53:03,260
The first job is to get the
hovercraft into service
440
00:53:03,284 --> 00:53:06,284
and plot a route out to
the nesting flamingos.
441
00:53:21,724 --> 00:53:24,860
The volcanic spring water
is soon replaced
442
00:53:24,885 --> 00:53:27,644
by a crust of razor-sharp
salt crystals.
443
00:53:28,804 --> 00:53:33,181
And for a machine that relies
on a delicate blow-up bottom,
444
00:53:33,204 --> 00:53:34,940
that's a problem.
445
00:53:34,965 --> 00:53:37,820
So, what we have here are
the plates of dried out soda
446
00:53:37,844 --> 00:53:40,420
which form on the mud
substrate underneath,
447
00:53:40,445 --> 00:53:43,101
and it just batters the hovercraft.
448
00:53:43,125 --> 00:53:45,501
We just cannot travel
across this stuff.
449
00:53:45,525 --> 00:53:47,340
It's impossible.
450
00:53:47,364 --> 00:53:52,085
If I was to skim my hand across
that, I would cut it to shreds.
451
00:53:53,844 --> 00:53:57,820
But crossing the soda crust is the
only way out of to the colonies,
452
00:53:57,844 --> 00:54:00,724
and so Matt and Darren
have to hope for the best.
453
00:54:03,125 --> 00:54:04,621
Unfortunately for Matt,
454
00:54:04,644 --> 00:54:07,300
the best position for his
flamingo-covered hide
455
00:54:07,324 --> 00:54:10,300
has a rather soggy floor.
456
00:54:10,324 --> 00:54:14,181
When the mud dries, it leaves
massive amounts of salt.
457
00:54:14,204 --> 00:54:18,005
Very scratchy, nasty
and aggressive salt.
458
00:54:19,684 --> 00:54:23,260
But sitting shin-deep
in toxic sludge
459
00:54:23,284 --> 00:54:26,981
is a price worth
paying for the view.
460
00:54:27,005 --> 00:54:30,260
And Matt is soon rewarded
with the birth of a chick
461
00:54:30,284 --> 00:54:32,764
right in front of his hide.
462
00:54:48,684 --> 00:54:50,701
The daily commute, however,
463
00:54:50,724 --> 00:54:53,684
is taking its toll
on the hovercraft...
464
00:54:55,565 --> 00:54:58,061
Oh, come on!
465
00:54:58,085 --> 00:55:02,300
..and its blow-up bottom is
literally being ripped apart.
466
00:55:02,324 --> 00:55:06,940
We've trashed 52 of these
that now need to be repaired.
467
00:55:06,965 --> 00:55:09,460
It's like travelling over sandpaper.
468
00:55:09,485 --> 00:55:12,460
So, what do you do when
your hovercraft needs
469
00:55:12,485 --> 00:55:15,684
replacement skirts and you're
in the middle of nowhere?
470
00:55:17,525 --> 00:55:20,380
Enter the local Maasai tribe,
471
00:55:20,405 --> 00:55:23,221
well known for their
needlework skills.
472
00:55:23,244 --> 00:55:25,820
There are only a few places
in the world that specialise
473
00:55:25,844 --> 00:55:28,380
in hovercraft maintenance,
474
00:55:28,405 --> 00:55:31,780
and Lake Natron is now
officially one of those hot spots.
475
00:55:31,804 --> 00:55:34,101
So if you're in the need
of any hovercraft services,
476
00:55:34,125 --> 00:55:36,005
you know where to go.
477
00:55:38,085 --> 00:55:41,501
Two days later, and after
a lot of serious sewing,
478
00:55:41,525 --> 00:55:44,724
the hovercraft is
ready to ride again.
479
00:55:47,844 --> 00:55:50,844
You look like the new
Tanzanian bobsleigh team!
480
00:55:55,764 --> 00:55:59,260
And getting back on the lake
couldn't have come at a better time,
481
00:55:59,284 --> 00:56:01,605
as the chicks are now on the move.
482
00:56:03,485 --> 00:56:06,925
Sadly, the new hide
position is no drier.
483
00:56:09,565 --> 00:56:14,820
We have an enormous creche of
hundreds of thousands of birds
484
00:56:14,844 --> 00:56:18,300
just pouring into the lagoon
from the salt mud,
485
00:56:18,324 --> 00:56:21,085
just constantly
chatting to each other.
486
00:56:22,764 --> 00:56:26,965
But the massive creche attracts
some unwelcome visitors...
487
00:56:28,405 --> 00:56:31,885
predators - marabou storks.
488
00:56:36,565 --> 00:56:40,005
These marabous, they know
exactly what they are doing.
489
00:56:44,085 --> 00:56:47,621
Soon, thousands of panicked
chicks are on the move,
490
00:56:47,644 --> 00:56:50,405
desperately trying
to avoid the predators.
491
00:57:05,005 --> 00:57:09,605
And it's a scene that will
live long in Matt's memory.
492
00:57:10,885 --> 00:57:14,181
I mean, it was literally like...
493
00:57:14,204 --> 00:57:15,925
..war had been declared.
494
00:57:16,965 --> 00:57:20,380
I mean, that's one of the... the...
495
00:57:20,405 --> 00:57:25,981
most amazing and frightening
and freaky wildlife scenes
496
00:57:26,005 --> 00:57:28,420
I've ever, EVER seen.
497
00:57:28,445 --> 00:57:32,061
And believe me, I've seen a few.
498
00:57:32,085 --> 00:57:36,101
And few places are more
challenging than Lake Natron,
499
00:57:36,125 --> 00:57:38,940
but to quote Matt,
if you can deal with
500
00:57:38,965 --> 00:57:42,141
the acrid and sulphurous
stink of the soda,
501
00:57:42,164 --> 00:57:46,420
the stinging eyes and the
chemical attack on your legs,
502
00:57:46,445 --> 00:57:51,684
then you could be rewarded with one
of the greatest spectacles on Earth.
503
00:57:56,284 --> 00:57:58,181
Next time...
504
00:57:58,204 --> 00:58:00,740
..the sun.
505
00:58:00,764 --> 00:58:04,684
Life on our planet is
fuelled by its energy.
506
00:58:09,525 --> 00:58:12,380
Everything must be perfectly tuned
507
00:58:12,405 --> 00:58:17,284
to the daily and yearly
rhythms of this vital force.
508
00:58:21,204 --> 00:58:24,181
The Open University has
produced a free poster
509
00:58:24,204 --> 00:58:26,661
exploring our perfect planet.
510
00:58:26,684 --> 00:58:31,940
To order, please
call 0300 303 0901.
511
00:58:31,965 --> 00:58:36,621
Or go to bbc.co.uk/perfectplanet
512
00:58:36,644 --> 00:58:39,644
and follow the links
to the Open University.
41311
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