90 degrees west
1 degree south
A world lost in the vastness of the Pacific
Home to the strangest life imaginable
Governed by nature's brutal forces
Islands which have transformed our understanding of life on earth
Galapagos lies remote, 600 miles off the coast of South America
astride the Equator
a scattering of 13 main islands with more than 100 islets, rocks and reefs
Each island has its own character
Some are cloaked in forest concealing life.
Others, smouldering giants, rugged and austere
home to pirates,
lair of dragons
All are the creation of one of the strangest features found anywhere on our planet
Galapagos are no ordinary islands
a mysterious prehistoric world
a landscape that profoundly influences life
These islands are plumbed directly into the heart of the earth
An artery of superheated rock rises to the surface from hundreds of miles beneath the crust
It's a volcanic hotspot
Galapagos constantly simmers even beneath the waves
These tiny bubbles of gas give a vital clue to the genesis of the islands
Sea vents are like pressure valves releasing growing tension from chambers of molten rock beneath the crust.
But if the pressure gets too much this magma reaches bursting point
The largest of all the Galapagos volcanos - Sierra Negra
recently blew smoke and ash 7 miles into the sky
The only rivers here are rivers of red hot rock at a scorching 1100 degrees Celsius
Galapagos is one of the most volcanic places on earth
The hotspot has been active for millions of years
building island after island
But it's not just how these islands are born
but where they're born that makes Galapagos so special
They emerged at the crossroads of four ocean currents
sweeping in from all corners of the Pacific
This interplay of warm and cold currents generates an extraordinary diversity of marine life
Over 500 species of fish make the most of these plankton-rich waters
Among them, residents like these barnacle blennies
and strange garden eels
Even ocean travelers like scalloped hammerheads gather in huge numbers
The converging currents that envelop Galapagos have also brought creatures to these shores from opposite ends of the Pacific
Galapagos sea lions are related to Californian sea lions, they came here from the North
And from as far south as the Subantarctic swam the ancestors of these birds - Galapagos penguins
The cold waters here allow them to survive on the equator
Fish shoals like these seek refuge from open ocean predators by keeping near the shoreline
But in Galapagos, this strategy can be risky
The coastal margins are the feeding grounds for the most aerobatic hunters
blue-footed boobies
When the fishing is good they gather in their thousands
Piercing calls synchronize an assault
Plunging in unison overwhelms their prey
Blue-footed boobies can dive in waters just 3 feet deep
But as they chase the shoals further in shore, they risk treacherous under currents and hidden rocks
But the biggest hazard is the battering surf
A wing smashed by the breakers means slow and certain death
Ghost crabs normally sift the sand for food, but they always got an eye out for something meatier
For creatures of the sea and air Galapagos is a welcome sanctuary
But these islands are not a choice destination for land animals
Those that came here were probably victims of flash floods
swept out from the mainland on rafts of floating trees
crossing 600 miles of ocean with no food and no freshwater
For any survivor, landing in a place like this would be a daunting prospect
Fernandina is the harshest, most volcanically active of all the Galapagos islands, a lava scar giant
This is a single monumental volcano with a caldera half a mile deep and nearly 4 miles wide
Where the volcano meets the sea dragons stir
It's hard to tell reptile from rock
These creatures are found nowhere else on earth
At dawn, the cold-blooded iguanas thaw from the night's chill absorbing the heat of the equatorial sun
When they've warmed the coastline of Fernandina comes alive
On this island, food is scarce
and the only way to find it involves a mission that seems suicidal
Only the larger adults dare to take the plunge
Marine iguanas are strong swimmers
With a single breath, they can comfortably dive to 30 feet
And all this effort for red and green algae
which thrive in the cold water
Marine iguanas are the world's only sea lizards
But when their distant ancestors were washed ashore in Galapagos
they were land animals
To survive, they were forced to tackle the ocean
This male must graze as quickly as he can
In these chilling waters, his body temperature falls fast
a 10-minute dive is about the most he can manage before his muscles seize up
Fighting the surge back to the shore is a Herculean task
And to make matters worse, he must now run the gauntlet of sea lions
They are the last thing the iguana needs
No harm is meant
it's nothing more than a rather one-sided game of cat and mouse
Marine iguanas take in too much salt with their food
But with the help of special glands they sneeze it out
They also welcome these resourceful visitors
Sally light foot crabs like to groom them for algae, parasites and dead skin
Lava lizards, far smaller reptilian relatives
have found their own ingenious ways to get by on this fierce shoreline
They enjoy a special relationship with the sea lions
The lizards rid them of flies which can be a ticklish nuisance
This sea lion accepts these predatory lizards
- both benefit
Survival depends on seizing every opportunity in this volcanic wasteland
Fernandina is the youngest of all the main Galapagos islands
It may have raised its head above the waves as recently as 30,000 years ago
It sits right above the volcanic hotspot in the far west of the archipelago
But how is it that the other islands created at this same hotspot
are now scattered over hundreds of miles of ocean to the east
All the islands are moving
They're traveling southeast at an inch or two a year on a massive tectonic plate which continually slides over the hotspot
Their journey begins as soon as they are born
And in their wake, new islands emerge
It's like a geological conveyer belt
So the archipelago we see today is just a snapshot in time
The oldest islands are in the east the youngest in the west
And as Fernandina ages, it will be carried on this conveyer belt to where the biggest of all the Galapagos islands currently resides
- Isabela
It's shaped like a giant sea horse, almost 100 miles long with a backbone of volcanos
Isabela is a teenage Galapagos island nearing a million years old
time enough for life to settle
It's giant calderas still tower more than a mile above sea level and are draped in vegetation
Although Isabela is softening with age it's still close enough to the hotspot to remain active
On its summits, like here on Alcedo volcano live the most iconic of all Galapagos animals
Their ancient trails carved over tens of thousands of years scar the landscape
Giant tortoises
They are the largest of their kind in the world weighing up to 550 pounds
Water is a scarce resource on this island and giant tortoises can survive months without it
But during the wetter season they gather to quench their thirst among a scattering of freshwater pools
A tortoise oasis
Around 5000 live here on Alcedo it's the greatest concentration found anywhere in Galapagos
Despite their extensive body armor,
tortoises are vulnerable to skin parasites which they are unable to remove themselves
so that they've developed a remarkable relationship with finches
When they need service it's a sort of slow motion pit stop
A finch eating frenzy
This giant tortoise could live to be 150 years old
During his lifetime, the island he roams - Isabela will be transported about 20 feet southeast on the Galapagos conveyer belt
But a million years from now that's about 6,000 tortoise lifetimes
Isabela will be carried right to the heart of the Galapagos archipelago
to where these mature mid-aged islands now lie
Santa Cruz has been pulled so far from the hotspot, but its volcanos are now ancient ruins
worn by the passage of time and swallowed by forest
Plants and soils now cover this aging island teeming with life
Its peaks are still high enough to generate clouds and receive regular rainfall
It's one of few places in Galapagos where there're magical freshwater pools
After a morning spent foraging at sea, frigate birds come here to bath their feathers and to sip on the wing
These forest basins are created by layer on layer of rich volcanic soil packed over porous lava
Elsewhere, the water filters its way through to reemerge near the coast in brackish lagoons
They are home to the most unlikely Galapagos residents
chance immigrants from the Caribbean
There are only about 500 flamingos in Galapagos limited to this rare habitat
Along the margins of these mature islands where it's drier and hotter
The landscape is dominated by giant cactus forest
Offering a perfect watchtower for the islands' top land predator
- the Galapagos hawk
Something on the shoreline catches its attention
Small lizards, birds and insects are the normal quarry
But for a few weeks a year there's much more on offer
Marine iguanas prefer to keep to the water's edge
But during the nesting season, females must brave it inland to find soft soil in which to lay their eggs
but she must go carefully
The hawk patiently waits to see if she drops her guard
She's reasonably safe close to her nest burrow
But stray too far from cover and she's courting trouble
The family has timed its breeding to coincide with this plentiful supply of food
Both parents take turns to hunt for and feed their growing chick
He's only a few weeks old but he's got a healthy appetite
He can comfortably eat half an iguana a day
As the Galapagos islands are carried further and further away from their place of birth, the volcanic hotspot
there's a remarkable progression
From barren rock and ash-covered deserts
life gets a grip
creeping inland to mellow and diversify
But the story doesn't end there
For every island is destined for a spectacular final flourish
The oldest of them all almost 100 times older than Fernandina
lies on the southeastern perimeter of the archipelago
- Espanola
Once a much larger volcano, all that remains is a dry, flat scrap of land
This island is dying
But it's been carried to a place where the nutrient-rich Humboldt current gives it a last breath of life
Its leeward northern shores have softened through time and there're choice hangout for Galapagos sea lions
A male controls a stretch of coastline attracting up to 30 females and their young
Females give birth to a single pub nourished on milk, rich in protein and fat
When the pubs are about a month old they join the local creche
It looks an easy life
But for this 500-pound beach master
there's no time to relax
Even with every ounce of effort, he'll be lucky to roam this stretch of sand for more than 3 weeks
This is why they are a constant challengers
This time the beach master wins leaving his rival battered and scarred
When the young sea lions are a year old or 2 old, the baby comes to training ground for social and hunting skills
These waters are so rich and the sea lions such effective predators that it frees up time to enjoy
few sea creatures are as playful
Though the northern side of Espanola is reasonably sheltered from prevailing winds
The southern side takes the full brunt of everything the ocean throws at it
Yet these cliffs are a mecca for seafaring iguanas and a crucial nesting platform for resident sea birds
The most majestic of all is a visitor, an ocean wanderer that roams the whole eastern Pacific
The waved albatross is the largest bird in Galapagos
with a 7-foot wingspan
After 6 months in the air first touchdown is never that simple
Virtually the entire world population
some 12,000 breeding pairs nest here on Espanola
The male waits for days, sometimes weeks for the arrival of his partner
Waved albatrosses may live for up to 50 years and pair for life, they rebond with the mesmerizing courtship dance
The whole colony comes alive with the clack of beaks
For such huge birds, mating is a gentle affair
The name 'waved albatross' comes from the delicate pattern of their feathers
Everything is gambled on a single egg which is incubated by both parents for 2 months, with each sitting for up to 2 weeks at a time
sometimes longer
And the result of such careful and diligent nurture
is this
As the chicks age, their parents foraging missions take them further and further afield
involving round trips of up to 2,000 miles
The chicks are fed on predigested squid and fish guzzling nearly half a gallon of oil in one big hit
Finally, after almost 6 months the juveniles and their parents begin to take to the air
The young albatrosses won't be back to breed for another 5 or 6 years
Their journey is just beginning
but this island's journey is nearing its end
Life here outlives the land
During the last 3.5 million years
Espanola has traveled over 100 miles from its place of birth - the Galapagos hotspot
Through that time, it's been cooling and contracting, fracturing and sinking
One day, it will end up beneath the waves
All the islands will eventually follow, carried on the conveyer belt to meet the same fate
Countless Galapagos islands have come and gone
They always have and they always will
Just as the islands mature through time,
so does our understanding of what makes them special
The first person to set foot on Galapagos
prayed only for deliverance from this wretched place
In the centuries to follow
all who came here to plunder shared his view
But in time,
one man
inspired by the landscape and wildlife would see things differently
discovering a secret that lay hidden within this island universe
A secret that would transform not just how we saw these islands
but our whole understanding of life on earth
His name was Charles Darwin
In the next program
we travel deeper into the heart of the Galapagos
and find out why these islands more than anywhere else are such a crucible for new life
Transcription by Andrew & Hattie