00:00:34,250 -- 00:00:36,457
One of nature's masterworks
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the ultimate long-distance athlete
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At full speed it uses less energy
than any animal its size
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The Kangaroo is shaped
by the land in which it lives
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one of the most
challenging places on earth
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Australia is a vast
ancient weathered land
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isolated from all others for
40 million years
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lt is a place of extremes
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00:01:52,083 -- 00:01:56,332
more like another planet
than another continent
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00:02:31,916 -- 00:02:35,207
Travelling over Australia's
3 million square miles
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00:02:35,416 -- 00:02:39,249
is like crossing an ocean of dry land
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00:02:48,541 -- 00:02:53,999
Primeval landscapes belie its rich
resourceful life
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00:03:06,833 -- 00:03:11,874
Australia is almost equal in size
to the continental United States
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lt is the driest
vegetated continent on Earth
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Surrounded by three oceans
it is the world's largest island
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lt shares no border with any other country
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00:03:50,208 -- 00:03:56,040
Here some of the Earth's oldest rocks
hold fossils from the dawn of life
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00:04:00,583 -- 00:04:04,499
ln its heartland are mountain ranges
that once rivalled Everest
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built up and worn down over time
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00:04:12,166 -- 00:04:16,957
and remnants of a once vast inland sea
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Most of Australia's native animals
are unique
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Their journey on this continental raft
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has taken them through cool forests
and fiery deserts
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and changed them forever
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00:04:42,458 -- 00:04:47,749
The survivors have been refined by
poverty and uncertainty
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00:04:52,333 -- 00:04:56,332
Some have climbed up out of adversity
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00:05:04,125 -- 00:05:08,082
Some have outrun all their predators
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00:05:15,791 -- 00:05:20,165
Most have adapted to hard
fickle conditions
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00:05:25,708 -- 00:05:30,124
A few are unchanged
since the days of the dinosaurs
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Now sheer diversity of species
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spreads the risk
that life is required to bear
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The story starts millions of years ago
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when Gondwana the great super continent
began to break apart
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00:05:53,666 -- 00:05:57,249
Africa South America
and lndia were formed
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00:05:57,458 -- 00:06:03,582
but Australia and Antarctica
were still joined as one last giant land
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00:06:03,791 -- 00:06:06,332
forested and lush
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00:06:16,916 -- 00:06:19,832
By 50 million years ago
the breakup was complete
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when Australia parted from Antarctica
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A massive ocean current
began to flow around the South Pole
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00:06:29,166 -- 00:06:34,540
and Antarctica's life perished
under a blanket of ice and snow
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00:06:37,458 -- 00:06:40,624
Australia pushed northwards
from the freezing latitudes
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and remained isolated
for the next 30 million years
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lt became an ark of survival
for its cargo of ancient life
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00:06:53,875 -- 00:06:56,499
Searing winds began to dry the land
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00:06:56,708 -- 00:07:00,832
and its moist rainforest all
but disappeared
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00:07:01,291 -- 00:07:05,165
At the centre
the desert was taking over
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00:07:05,375 -- 00:07:08,540
Australia's plants
and animals faced a choice
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00:07:08,750 -- 00:07:12,665
adapt to the drying conditions
or retreat
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00:07:22,583 -- 00:07:26,915
Now the symbol of
Australia's red heart is Uluru
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00:07:27,125 -- 00:07:30,207
the Earth's largest exposed rock
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00:07:30,416 -- 00:07:34,957
lt commemorates the relationship
between life and this land
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00:08:01,791 -- 00:08:05,457
Today Australia is the
Earth's flattest continent
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00:08:05,666 -- 00:08:10,207
lts mountains were worn to their stumps
millions of years ago
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00:08:13,291 -- 00:08:16,165
The Nullarbor plain on its southern coast
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00:08:16,375 -- 00:08:20,082
has the world's
longest unbroken coastal cliffs
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00:08:20,291 -- 00:08:23,749
Once you could walk to Antarctica
from here
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00:08:43,041 -- 00:08:49,165
lf the dry Outback is a land ocean
these parallel sand dunes are its waves
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00:08:49,750 -- 00:08:54,749
Stretching beyond the horizons
they cover nearly half of the continent
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00:09:04,541 -- 00:09:07,374
Millions of years of rain
and drying winds
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00:09:07,583 -- 00:09:11,624
long ago leached the goodness
from most of its soil
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00:09:11,833 -- 00:09:18,082
ln the red centre there is no regular
predictable pattern of rainfall
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00:09:18,291 -- 00:09:24,915
Poor soils and a savage climate
now challenge all life in this land
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00:09:48,208 -- 00:09:51,499
Nature responded to the
changing conditions
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00:09:51,708 -- 00:09:55,207
The kangaroo started
its journey as a marsupial possum
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the size of a mouse
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00:09:58,625 -- 00:10:02,874
As forests contracted some kangaroos
evolved to live in the trees
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00:10:03,083 -- 00:10:06,082
and others learned to eat grass
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00:10:09,666 -- 00:10:13,082
When food is plentiful
the males are active
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00:10:13,291 -- 00:10:16,082
and courtship disputes are
traditionally settled
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00:10:16,291 -- 00:10:18,874
with a round or two of kick-boxing
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00:10:21,958 -- 00:10:26,374
Mothers and babies
sensibly keep out of the way
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00:10:46,833 -- 00:10:50,540
On most continents animals breed
in response to the seasons
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00:10:50,750 -- 00:10:53,707
ln Australia
it is the availability of food
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00:10:53,916 -- 00:10:57,082
that prompts the kangaroo to reproduce
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00:11:01,416 -- 00:11:06,207
To capitalise on good times
the mother can support a production line
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00:11:06,416 -- 00:11:09,082
one joey in the pouch one at foot
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00:11:09,291 -- 00:11:12,499
and another in the womb as an embryo
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00:11:12,958 -- 00:11:14,582
She can even supply her babies
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00:11:14,791 -- 00:11:17,999
with two different formulas
of milk at the same time
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00:11:18,208 -- 00:11:21,124
one for each generation of young
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00:11:46,541 -- 00:11:51,290
The koala evolved from the
same marsupial possum as the kangaroo
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00:11:51,500 -- 00:11:54,165
When the baby
is big enough to leave the pouch
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00:11:54,375 -- 00:11:56,832
it rides on its mother's back
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00:12:05,500 -- 00:12:06,915
Like the kangaroo
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00:12:07,125 -- 00:12:10,207
the koala evolved
in the moist rainforest
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00:12:10,416 -- 00:12:15,874
As the forest dried it adapted
to live on the leaves of the gum tree
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00:12:20,666 -- 00:12:22,457
Now it drinks little water
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00:12:22,666 -- 00:12:25,082
and its digestive system
can extract moisture
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00:12:25,291 -- 00:12:29,790
and nutrients from leaves that would
be toxic to most other mammals
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00:12:33,541 -- 00:12:39,457
Koalas use as little energy as possible
resting about 19 hours a day
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00:12:44,375 -- 00:12:48,957
Some members of the family however
are active at any hour
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00:12:49,166 -- 00:12:53,874
When moving from tree to tree
they normally descend backwards
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00:12:56,500 -- 00:13:02,624
Consejuently tree top traffic jams can
sometimes leave one out on a limb
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00:13:38,166 -- 00:13:43,749
For years on end much of the Australian
inland receives little or no rain
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00:13:43,958 -- 00:13:48,707
Two thirds is classified arid
and one half is desert
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00:13:49,166 -- 00:13:54,082
The Outback as it is called
covers most of the continent
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00:14:00,541 -- 00:14:03,582
By rights nothing should live here
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00:14:03,791 -- 00:14:06,707
this ought to be a lifeless wasteland
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00:14:06,916 -- 00:14:08,999
But it is not
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00:14:10,333 -- 00:14:14,582
The closer we look the more we find that
some of Australia's forest inhabitants
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have met the desert's challenge
with subtlety and resource
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00:14:21,916 -- 00:14:27,082
Now a diverse underworld of ants
rodents marsupials and reptiles
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00:14:27,291 -- 00:14:31,415
are among the most
successful desert dwellers on Earth
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00:14:32,666 -- 00:14:38,332
By day most life in this land ocean
is hidden beneath the surface
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00:14:47,958 -- 00:14:52,540
Many of the desert animals
come out to feed in the cool of night
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00:14:52,750 -- 00:14:57,124
These tiny hopping mice survive
because they rarely need to drink
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00:14:57,333 -- 00:15:02,790
Most of the water they require
is contained in the seeds they eat
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00:15:06,875 -- 00:15:10,249
ln the heat of the day
they huddle together in deep burrows
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00:15:10,458 -- 00:15:15,249
creating a humid atmosphere
that helps to conserve moisture
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00:15:25,125 -- 00:15:27,957
ln this arid region hardy mulga trees
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00:15:28,166 -- 00:15:33,332
provide food for one of Australia's
four thousand species of ants
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00:15:43,041 -- 00:15:44,665
Six feet below the surface
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00:15:44,875 -- 00:15:51,207
honey ants hang like clusters of golden
grapes in cool humid larder chambers
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00:15:51,458 -- 00:15:55,874
These specialised ants
are living honey pots
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00:16:02,166 -- 00:16:05,124
They are force fed by worker ants
on nectar
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00:16:05,333 -- 00:16:09,040
harvested from the sap of mulga trees
growing above
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00:16:10,208 -- 00:16:11,499
When food is scarce
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00:16:11,708 -- 00:16:17,457
these honey pots feed the workers
by regurgitating their nectar on demand
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00:16:21,041 -- 00:16:26,707
Their underground storehouse will see the
whole colony through the toughest of times
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00:16:42,166 -- 00:16:45,874
Arid Australia
is the land of the lizards
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00:16:46,083 -- 00:16:50,749
There can be up to forty seven different
varieties in just one area
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00:16:52,875 -- 00:16:57,832
The Thorny Devil has a sticky tongue
and it's picky about what it eats
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00:17:00,958 -- 00:17:05,832
Out here black ants are one food
that never runs out
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00:17:24,625 -- 00:17:26,999
The devil is perfectly adapted
to the desert
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00:17:27,208 -- 00:17:30,290
lts prickly skin collects moisture
from the air
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00:17:30,500 -- 00:17:32,790
and a system of fine channels along
its body
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00:17:33,000 -- 00:17:35,957
carries the water to its mouth
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00:17:54,041 -- 00:17:58,207
The biggest and most fearsome of the
desert lizards is the perentie
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00:17:58,416 -- 00:18:01,707
which is both scavenger and predator
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00:18:02,583 -- 00:18:07,582
This lizard can exceed six feet in length
and outrun a human
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00:18:08,791 -- 00:18:12,165
lt hunts anything
including the most aggressive
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00:18:12,375 -- 00:18:16,457
and deadly of Australia's many snakes
the King Brown
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00:18:31,916 -- 00:18:36,707
Sometimes though the King Brown
is more than even a perentie can manage
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00:18:52,291 -- 00:18:56,457
The venom from this snake's bite
will kill a human in minutes
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00:18:57,208 -- 00:19:00,415
Luckily for the perentie it is immune
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00:19:19,125 -- 00:19:23,040
While much of Australia's life
was adapting to the dry inland
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00:19:23,250 -- 00:19:28,874
some of its plants and animals retreated
to the mountains of the east coast
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00:19:40,916 -- 00:19:43,082
Here moist valleys and cool peaks
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00:19:43,291 -- 00:19:48,290
provide a haven for Australia's
living links with the past
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00:20:00,583 -- 00:20:03,499
ln scattered pockets
of primitive rainforest
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00:20:03,708 -- 00:20:08,749
descendants of Gondwana's
original plants and animals thrive today
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00:20:18,083 -- 00:20:22,957
These Antarctic Beech trees began
growing between 3 and 5 thousand years ago
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00:20:23,166 -- 00:20:27,749
but their roots
are in the ancient super continent
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00:20:48,541 -- 00:20:50,915
Most of Australia's native plants
and animals
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00:20:51,125 -- 00:20:55,790
began to evolve in wet
cool forests like these
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00:21:01,916 -- 00:21:05,665
One of the most remarkable living links
with that ancient world
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00:21:05,875 -- 00:21:10,915
is found in the creeks
and freshwater rivers of the east coast
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00:21:23,416 -- 00:21:26,457
The Platypus suckles
its young like a mammal
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00:21:26,666 -- 00:21:29,499
yet lays egg like a lizard
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00:21:33,083 -- 00:21:34,999
lt hunts under water with its eyes shut
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00:21:35,208 -- 00:21:39,040
using electric sensors in its bill
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00:21:39,375 -- 00:21:42,082
The first Europeans
to see it were dumbfounded
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00:21:42,291 -- 00:21:47,499
To them it was a living contradiction
if not a practical joke
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00:21:48,416 -- 00:21:53,249
The Platypus though has survived
for 120 million years
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00:21:53,458 -- 00:21:57,165
Today it exists nowhere else on earth
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00:22:10,666 -- 00:22:13,290
The nearest surviving relative
of the Platypus
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00:22:13,500 -- 00:22:15,999
is the Echidna
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00:22:17,166 -- 00:22:20,249
With its tubular snout and long
sticky tongue
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00:22:20,458 -- 00:22:23,790
it lives on ants and termites
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00:22:27,291 -- 00:22:30,624
Unlike the Platypus the Echidna moved out
of the cool forests
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00:22:30,833 -- 00:22:34,332
and now ranges across the whole continent
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00:22:39,416 -- 00:22:41,582
When threatened it digs in rapidly
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00:22:41,791 -- 00:22:46,249
presenting an array of sharp spines
to its attacker
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00:23:07,083 -- 00:23:08,124
Drought
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00:23:08,333 -- 00:23:11,582
lt can last for months
or years at a time
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00:23:12,000 -- 00:23:16,624
Long periods without
rain push all life to the limit
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00:23:29,041 -- 00:23:32,874
The young and the old
are first to feel the effects
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00:23:36,916 -- 00:23:42,457
Clear skies parched earth and searing
heat become the rule of life
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00:23:43,958 -- 00:23:47,665
Some will perish before the next rains come
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00:23:56,333 -- 00:23:58,207
Now the kangaroos of the desert
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00:23:58,416 -- 00:24:02,624
call on another remarkable strategy
for survival
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00:24:07,250 -- 00:24:10,874
The female can halt the growth
of her developing embryo
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00:24:11,083 -- 00:24:15,499
keeping it in a state of suspension
until conditions improve
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00:24:15,708 -- 00:24:18,957
Only then will she give birth
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00:24:24,291 -- 00:24:29,249
For the joey already born
the future is now uncertain
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00:24:31,291 -- 00:24:36,165
But the unborn embryo will be ready
when good times return
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00:24:43,583 -- 00:24:48,124
Surviving kangaroos will either move
to new territory in search of food
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00:24:48,333 -- 00:24:54,374
or batten down near remaining waterholes
while at least some grass remains
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00:25:09,791 -- 00:25:13,457
Emu families
have a similar hard choice to make
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00:25:13,666 -- 00:25:17,415
Whatever they decide it will be a gamble
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00:25:40,791 -- 00:25:43,082
Relief from drought is unpredictable
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00:25:43,291 -- 00:25:47,332
and often arrives a long way
from where it is needed
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00:25:47,958 -- 00:25:50,415
Each year the tropical wet season
brings storms
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00:25:50,625 -- 00:25:53,999
and flooding to Australia's far north
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00:25:57,208 -- 00:26:03,457
As the monsoon unfurls curtains of rain
a transformation begins
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00:26:37,166 -- 00:26:41,790
As the wetlands fill crocodiles emerge
from scattered waterholes
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00:26:42,000 -- 00:26:45,832
where they've been confined
during the dry season
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00:26:46,083 -- 00:26:48,582
They will build nests above
the high water level
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00:26:48,791 -- 00:26:51,707
and lay up to 100 eggs
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00:26:59,875 -- 00:27:05,790
Vast networks of wetlands that have been
dry since last season are flooded again
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00:27:24,916 -- 00:27:31,040
Sometimes this powerful event
can also transform Australia's arid centre
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00:27:34,708 -- 00:27:38,165
ln years when rains are heavier
and more widespread than usual
193
00:27:38,375 -- 00:27:42,707
the water flows inland
to the parched interior
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00:28:04,458 -- 00:28:08,457
Slowly heading south
water spreads across the plains
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00:28:08,666 -- 00:28:13,499
ln six months or more
it may reach the centre of the continent
196
00:28:48,541 -- 00:28:52,415
Under cloudless skies
the water creeps quietly inland
197
00:28:52,625 -- 00:28:55,957
filling hundreds of dry waterways
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00:29:14,125 -- 00:29:18,749
ln dry sandy creek beds
millions of tiny drought resistant eggs
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00:29:18,958 -- 00:29:21,624
like seeds are waiting
200
00:29:28,333 -- 00:29:33,249
Subterranean life that may have been dormant
for years begins to stir
201
00:29:42,666 -- 00:29:44,332
Stimulated by seeping water
202
00:29:44,541 -- 00:29:48,749
the burrowing frog
awakes from its long sleep
203
00:29:50,958 -- 00:29:55,457
Carefully it parts the membrane that has
kept it moist through the drought
204
00:30:03,666 -- 00:30:06,749
Like the frog many creatures are primed
205
00:30:06,958 -- 00:30:10,082
for the good times
that are about to unfold
206
00:30:13,291 -- 00:30:15,832
Alerted by an ancient program
in their minds
207
00:30:16,041 -- 00:30:19,332
Egrets arrive
and take up feeding positions
208
00:30:19,541 -- 00:30:23,874
Fish have already started reproducing
in streams that until a week ago
209
00:30:24,083 -- 00:30:26,957
were tracks of dry sand
210
00:30:46,416 -- 00:30:50,415
Thousands of waterbirds join in a frenzy
of feeding and breeding
211
00:30:50,625 -- 00:30:54,332
that may happen only once
or twice in a decade
212
00:31:36,458 -- 00:31:41,499
Briefly the desert blossoms
in a colourful tide of new life
213
00:31:54,833 -- 00:32:00,582
One of the few large predators in this
land also participates in the bonanza
214
00:32:03,833 -- 00:32:06,040
Australia's wild dog the dingo
215
00:32:06,250 -- 00:32:10,582
arrived from nearby Asia about
four thousand years ago
216
00:32:15,583 -- 00:32:19,332
lts pups will feed on the plentiful
supply of rodents and reptiles
217
00:32:19,541 -- 00:32:23,499
that are also multiplying
in the abundant conditions
218
00:32:47,791 -- 00:32:49,332
Tens of thousands of pelicans
219
00:32:49,541 -- 00:32:53,874
are drawn by the
irresistible call of inland water
220
00:32:54,333 -- 00:32:57,374
Responding to reflections far away
in the sky
221
00:32:57,583 -- 00:33:04,082
the birds fly hundreds of miles to gather
on the shores of newly filled desert lakes
222
00:33:14,958 -- 00:33:17,624
With more than
half a million nesting birds
223
00:33:17,833 -- 00:33:21,290
colonies of this size are a rare event
224
00:34:05,166 -- 00:34:08,332
Pelicans normally breed in small
scattered communities
225
00:34:08,541 -- 00:34:11,290
producing one chick a year
226
00:34:14,958 -- 00:34:18,499
Here they'll produce five
or more in quick succession
227
00:34:18,708 -- 00:34:23,707
and go on doing so
as long as the food supply lasts
228
00:34:34,625 -- 00:34:36,082
Millions of years ago
229
00:34:36,291 -- 00:34:41,540
pelicans were breeding in the vast lake
system that covered much of the interior
230
00:34:47,958 -- 00:34:53,540
Ancestral knowledge seems to draw them
back to their primeval home range
231
00:35:18,625 -- 00:35:23,707
The water ends its longjourney at the
centre of the continent in Lake Eyre
232
00:35:37,791 -- 00:35:39,707
Nearly a million square miles
233
00:35:39,916 -- 00:35:44,332
of the continent drains into the
world's largest dry salt lake
234
00:35:44,541 -- 00:35:48,665
lt fills completely only about
twice a century
235
00:36:26,875 -- 00:36:30,415
lnevitably the flow of water stops
236
00:36:36,416 -- 00:36:40,749
The earth and blasting sun suck away
at the stagnant pools where life
237
00:36:40,958 -- 00:36:44,665
newly born there is on borrowed time
238
00:36:54,166 -- 00:36:55,832
Trapped by receding waters
239
00:36:56,041 -- 00:37:00,457
some of these fish will provide a final
feast for the birds
240
00:37:05,833 -- 00:37:09,249
Millions more
will return to the mud of the riverbed
241
00:37:09,458 -- 00:37:12,582
enriching it for the next generation
242
00:37:24,333 -- 00:37:26,040
With their food supply running low
243
00:37:26,250 -- 00:37:29,915
the great flocks of pelicans
become nomads once more
244
00:37:30,125 -- 00:37:35,124
rising to search for that
far flash of water over the horizon
245
00:37:40,625 -- 00:37:44,790
Those who have left their run too late
go back into the earth
246
00:37:59,333 -- 00:38:02,749
The familiar desert
will now reclaim this place
247
00:38:02,958 -- 00:38:06,915
Suns will scorch it
winds will dry it out
248
00:38:14,833 -- 00:38:19,249
Most living creatures will dig in
and take refuge underground
249
00:38:19,458 -- 00:38:23,499
Some will flee to the gentler edges
of this great land
250
00:38:23,708 -- 00:38:28,665
And the hardy ones will await a new flood
in some future year
251
00:38:42,500 -- 00:38:47,707
ln Australia life has struck an
unlikely deal with an uncertain climate
252
00:38:54,250 -- 00:38:56,624
The continent has been a ship of refuge
253
00:38:56,833 -- 00:38:59,374
for an alternate order of ancient life
254
00:38:59,583 -- 00:39:01,874
as it crept northward through the eons
255
00:39:02,083 -- 00:39:06,040
its passengers have had to adapt
again and again
256
00:39:20,833 -- 00:39:22,749
ln this land beyond time
257
00:39:22,958 -- 00:39:28,165
life has learned to ride out the hard times
and flourish in the good times
258
00:39:28,375 -- 00:00:00,-001
Far more than merely surviving
life has triumphed in Australia