23x06 - Cuba: Wild Island of the Caribbean

[bunniefuu]

Cuba is a tropical paradise, but
it's a paradise full of surprises.

Beyond the cities
lives a wild mysterious island

teeming with uniquely Cuban animals.

Each bizarre creature is a story
of triumph against staggering odds.

How did they get here?
And how have they survived?

Cuba holds many mysteries
that are only now being revealed.

It's a story
that stretches back in time,

beyond the period
of human settlement.

It's a tale of titanic forces,

ocean currents, wild storms
and an amazing island ark.

Cuba has a long history, from 1492
when Columbus landed,

through the Spanish colonial period

that created so much
of old Havana,

to modern times of revolution,

Communism and the rule
of Fidel Castro.

Millions of tourists are drawn
to Cuba each year

by the attractions of music, cigars
and tobacco.

But beyond the fields, the cities
and the beaches lies a wild Cuba -

a little known world with a much
longer but equally colourful

and fascinating history.

We can see part of that history
alive and well

in the tropical seas
that surround Cuba.

The coral reefs teem with fish.

They can claim to be the best in the
Caribbean, and this, in part,

is due to Cuba's recent past.

For since the revolution,
in 1959,

these seas have
had little fishing pressure.

This reef may look much the same now
as it did thousands of years ago.

And now, as then, there are predators
searching for an opportunity.

The top predator
is the Caribbean reef shark.

The seas around Cuba
are spectacular -

in their clarity and the
profusion of life they support.

But the sharks and the coral fishes
are not exclusively Cuban,

for they can be found
elsewhere in the Caribbean.

If you want to see uniquely
Cuban wildlife,

you need to look back to the land
and to understand the nature of Cuba

you must go back in time.

Cuba's wild history
stretches back millions of years.

During the last Ice Age, much of the
world's water was locked up as ice

and so the sea level was lower.

Cuba was a bigger and broader island.

What are shallow seas today
were then lush freshwater swamps.

These swamps covered much of Cuba,
the Bahamas and the Cayman Islands

and must have been home
to millions of mosquitoes

and to a variety of other creatures,

including this...

the Cuban hutia.

These large rodents

can still be found today,
along with the mosquitoes.

They tend to stick to the pockets
of high ground avoiding the water...

..and for good reason.

There's another creature
that lives in the swamp -

Cuban crocodile.

This crocodile can grow to nearly


It has the reputation of being
the most aggressive crocodile

in the world.

The Cuban crocodile evolved
here about two million years ago

and it evolved alongside the hutia.

Occasionally hutias have to venture
out to reach better feeding.

They're neither the most elegant
nor efficient of swimmers.

The commotion alerts the crocodiles.

Now it's a matter of time,

will the hutia reach dry land
before the crocodiles reach it?

The crocodile evolved to hunt hutias
and not just in the water.

The hutia may appear safe
when feeding in the trees,

but appearances can be deceptive.

The crocodiles have
a fine sense of smell

and pick up the scent of a hutia
carried on the tropical air.

Swimming slowly upwind,

they home in on the isolated tree
from over a mile away.

The hutia is six feet up the tree.

But this crocodile
has a way of reaching its goal.

The hutia has no way of escape.

The crocodiles have
all the time in the world

to improve their
high-jump performance.

The leaping crocodiles
evolved on Cuba

in the swamps that covered
vast areas during the ice age.

But the swamps were
not always that large.

As the sea level changed,

some wetlands would have been
transformed into forests.

Today, the dry forest is the home
of many of the birds of Cuba

like the Cuban parrot.

Birds must have flown to Cuba
over a period of millions of years.

The more recent colonists,
like the turkey vulture,

have remained the same as birds
on the American continents.

Other more ancient arrivals
evolved into Caribbean birds

found on several of the islands.

But some birds are wholly Cuban,
found nowhere else on Earth.

Their ancestors, typically
woodland birds, were ideal pioneers.

They were strong flyers,
able to reach the island.

But once there, they stayed put
in the forests.

Over time, these birds changed into
uniquely Cuban creatures,

like the national bird -
the Cuban trogon.

Over many generations, the birds
adapted to their island home,

the process of evolution
moulding them to their surroundings.

There were new plants
and animals to feed on

and new patterns of weather
to cope with.

The climate has an
important influence on animals.

Cuba has distinct
wet and dry seasons.

Many of the birds evolved to breed
with the onset of the summer rains.

THUNDER CRASHES

The heavy rains stimulate
not only the birds.

This event triggers a wildlife
spectacle that begins below -

on the forest floor.

The trees grow
straight out of the rock.

This is an old coral reef,
exposed by the changing levels

of the sea and land.

These crabs evolved about
four million years ago.

They're true land creatures,
but they still breathe using gills

like their marine ancestors,
so they dehydrate easily.

They time their emergence to the
high humidity brought by the rains.

The males leave the rocky-floored
forest and dig a shelter

in the soft soil
closer to the coast.

Here they wait for the females.

The land crabs can range in colour

from dark red to bright yellow,
but they're all the same species.

Some males mate in the shelter.

Other males mate beside
their tunnels,

fending off other
interested parties.

The male's embrace may look gentle,

but with claws
there's a limit to tenderness.

Once the sperm is transferred,
the crabs separate

and the males and females
make their way back into the forest.

After a few weeks,
the females reappear

carrying their ripe eggs in a pouch.

Again the numbers grow as the crabs
move once more out of the forest.

They're headed for the sea,
their ancestral home.

The urge to spawn is so great
that nothing stops the migration.

The crabs climb walls
and cross paths.

They even walk through
the grounds of hotels.

Their journey may be as long as six
miles and can take several days.

They need to find shelter
during the hottest part of the day

if they're not to die of dehydration.

Trees provide natural cover.

But today the crabs can also enjoy
the benefits and luxuries provided

by tourist hotels.

They swarm up the windows and crawl
under the shutters

to avoid the hot ground
and direct sun.

They're quite prepared to share
a room with human guests,

especially if there's
air conditioning at night.

The next morning, the swarm
is on the move

on the last part of their journey.

How the crabs know where the coast
is, and in which direction to move,

is a mystery.

The final part is the toughest.

The sharp pinnacles of an old
coral reef are like

miniature mountains for the crabs.

In the cool of the morning,
the crabs finally reach their goal.

They can only spawn when the sea is
calm, for otherwise they'd risk

being washed off the rocks
and swept out to sea.

These are land crabs
and they cannot survive in the sea.

They shake their precious cargo
of eggs into the sea.

This is their last connection
with their ancestral home.

The eggs hatch immediately

and the next generation starts
its life in the Caribbean Sea.

The sea becomes a soup
of crab larvae

and the bounty does not go unnoticed.
Mullet suck in the eggs.

But they have no real impact -
the numbers are overwhelming.

For a few weeks, the coastline
of the infamous Bay of Pigs

is awash with billions of baby crabs.

Wave after wave arrive
at the coast to spawn.

Every day, new crabs shed their eggs
into the Bay of Pigs.

Once each female's pouch is empty,
she heads back to the forest.

It's on the return journey that the
crabs face their greatest danger.

There are millions of them in
this one small area of Cuba.

This annual spectacle
has taken place every year for aeons.

Evolution has hard wired
it into the crabs' brains.

They know how to find the sea
and how to avoid dying from heat

and loss of water.

But evolution could not
prepare them for the modern world.

They have no way
to deal with traffic.

HORN TOOTS

Tourist taxis give the crabs
a chance to escape to safety.

But other traffic
is less considerate.

Instinct tells the crabs
that shade offers shelter.

The result is carnage.

TYRES CRUNCH

Nothing in their four-million-year
history could prepare them

for Russian trucks.

The dead ones attract
other crabs for an easy meal.

But for many, it's their last.

The walking wounded and survivors
head for the side of the road

and the safety of the verge
and the dry forest beyond.

They'll not venture out of the forest
again until the rains return.

Living in the same forest is a bird
whose ancestors may have arrived

on Cuba around the time
of the crabs.

The bee hummingbird.

It's the smallest bird in the world -
two inches long.

That makes it the same size
as a dragonfly.

The male weighs only
a five hundredth of an ounce.

This is half the weight of a penny.

Yet, despite their size,
the birds are very aggressive.

Each male defending its territory
with song and flashes of iridescence.

If this fails,
the males fly up over 300 feet

and then power dive down
on their opponent.

The males display all day,
using large amounts of energy.

When they power dive,
they reach speeds of over 90 mph.

The wings beat 200 times per second
and the heart rate

is a staggering 1,000 beats
per minute.

The male's display
not only drives off intruders,

it also attracts females.

Like the male,
she has huge energy needs.

Whilst incubating, she reduces her
body temperature to decrease the time

she must leave the eggs unguarded.

WINGS REVERBERATE

These smallest of birds
live on an energy knife-edge.

A lowered body temperature

means less need for food and so the
female can return to her nest sooner.

The male guards his patch of forest
not for the benefit of the female,

but for his own.

For the territory holds his
most precious resource - flowers.

He may sip from as many as


the nectar he needs to fuel
his energetic lifestyle.

The bee hummingbird is a miniature
specialist, feeding on small flowers

that insects normally visit.

The reason is the ancestors
of the bee hummingbird

did not have Cuba to themselves.

They shared the island with
another hummingbird

and today there are
still two species.

The Cuban Emerald is over twice
the size of the bee hummingbird,

but still smaller than a chickadee.

The Cuban Emerald,

like the smaller bee hummingbird,
is found nowhere else on Earth.

The two hummingbirds evolved on Cuba
and, by becoming different in size,

avoided competing with each other.

Being bigger, the Cuban Emerald
is more of a generalist

and feeds from
a wider range of blossoms.

They include this
curiously shaped flower.

But this blossom is not
designed for hummingbirds.

The birds are really plundering
nectar

destined for another creature,
one that only appears after sunset,

and then only on the
darkest of nights.

These creatures shun light
and can only be recorded

by infra-red or black light.

Nectar-feeding bats fly as far
as 50 miles in search of food.

They first detect
flowering trees by scent.

After the initial approach,

the bats then use their
powers of echolocation.

The flower's shape reflects
a narrow beam of ultra-sound

back to the bats,
guiding them to the nectar.

The bats extract the nectar
in less than a second.

Nectar is a rich source of energy and
the bats quickly fill their stomachs

and then return to their cave.

Here, the nectar feeding bats
are not alone,

for there are over


Like the birds,
the different kinds of bats

arrived over many millions of years.

Many of the secrets of Cuba's
bats have been discovered

by Professor Gilberto Silva.

He's studied them for over 50 years.

Cuba is largely composed of
limestone and is riddled with caves.

There's a higher density of caves in
Cuba than any other place on Earth.

This particular cave
is the home to a rather special bat.

Years ago, when Gilberto first
entered its sleeping chamber,

he nearly died -

there was so little
oxygen to breathe.

How the bats survive
in their anoxic chamber

remains one of Cuba's mysteries.

Nowadays, Gilberto waits outside
for the bats to come to him.

Like the nectar bats
they will not fly in light.

Gilberto captures them
using the sound of their wings alone.

Only when safely in the hand,
can he use a lamp.

The butterfly bat has that very
Cuban characteristic of being small.

In fact, it can claim to be
the smallest bat in the world.

Like the diminutive hummingbird, this
tiny bat can only be found on Cuba.

Other species of bats
crowd larger caverns.

The combined body heat of
hundreds of thousands of them

raises the temperature to
over 110 degrees Fahrenheit.

The urine-soaked floor ensures
the chamber is very humid.

Perfect for bats...

and purgatory for anyone other
than a dedicated bat scientist.

Cuba is home to millions of bats.

And with so many bats, it's no
surprise that there's a predator.

The cave boa.

These snakes have a special technique
for catching their prey.

In the pitch dark, the draft of a
wing beat stimulates them to strike.

The caves that
are home to the snakes and bats

were formed by underground rivers.

Over millions of years, as the
level of land and sea fluctuated,

these rivers found new courses.

New caves were created
and old ones drowned.

The result is that water filled
caverns are scattered throughout

the limestone landscape
of the dry forest.

Some connect with the sea
and have salt water.

Here, surrounded by forest,
reef fish can feed on fruit.

These caverns
reveal their past to divers.

Their chambers are decorated
with stalactites and stalagmites

that could only have formed
when the cave was full of air.

The water is crystal clear, filtered
by its journey through the limestone

and light can penetrate
deep into the cavern.

But beyond the limits of daylight

is a world into which only
specialised cave divers may venture.

The divers always explore as a team,
for this is dangerous work.

This Cuban cave diving group

has been exploring and mapping
this dark world for many years.

These inner recesses of the Cuban
underworld hold their own secrets -

the remains of a human
that fell in long ago.

But there's life here too -

over 500 yards from the surface,
beyond the narrowest of passageways.

The life this deep
in the cave has evolved

to live in perpetual darkness.

The light of the diver's torch
may be the first

that this fish has ever experienced.

And it doesn't like it.

The fish's scientific name
is lucifuga -

the animal that flees from light.

And that's most appropriate.

Little is known about these unique
Cuban cave dwellers,

for they're rarely visited
and shun light.

It's thought they evolved from fish
that lived in the depths of the sea.

That dark world

may well have prepared their
ancestors for life in these caverns.

Here, they slowly lost their eyesight
and the pigment in their skin -

becoming mysterious
ghost-like creatures.

It should surprise no-one that fish
arrived on Cuba by swimming,

but 12 million years ago

a less obvious candidate
arrived by the same means.

The ancestors of this lizard,
the rock iguana, crossed the sea

from Central or South America -
a distance of 125 miles or more.

Though they look incongruous, the
iguanas are actually good swimmers

and when they tire, they can inflate
their chests and float like corks

whilst they take a break.

By a combination of hitching lifts
on floating vegetation, drifting

and swimming, a few iguanas found
their way to the shores of Cuba.

Those that did,
became the founders of a dynasty.

No competitors and lots of space -

Cuba must have seemed a paradise.

A paradise, that is,
apart from the flies.

FLIES BUZZ

The large flies accompany the iguanas
and drink the fluid in their eyes.

Like most creatures that arrive
on islands -

but unlike the bee hummingbird
and the butterfly bat -

the iguanas grew large.

An adult male can be five feet long
and weigh as much as 20 pounds.

Despite their fierce appearance
and impressive size,

rock iguanas are, for the most part,
peaceful vegetarians.

The iguanas arrived on Cuba
before the crocodiles

and many of the birds, bats and fish.

But another kind of lizard
had colonised Cuba

long before the iguanas.

They were carried to these shores

on rafts of floating vegetation,
as long ago as 30 million years.

At that time the sea level
was changing rapidly

turning mountain ranges into islands.

And isolated on each island,
new species

of these small Anolis lizards
evolved.

Today, there are around


of these fiercely
territorial creatures.

Some species are adapted to life
on the rocky forest floor.

Others live on sedges and grasses.

Many dispute for space
on the bushes and low trees.

They all have a dewlap,
but have evolved

different ways of showing it off.

There are even anoles in the tops of
tallest palms, like this blue anole.

The story of the anoles is a
clear example of an ancestral animal

evolving into many different species
to fill all the different habitats.

The anoles have had 30 million years
to evolve

into a huge array of species, each
carving a niche for itself on Cuba.

But there were animals on Cuba
before the anoles arrived.

One possible ancient Cuban

can be found in the woods that clothe
these steep limestone mountains.

The Cuban tody is diminutive.

There are only five species of
tody in the world -

all found on Caribbean islands -

and the Cuban tody
is the most colourful of them all.

TODY CHEEPS GENTLY

Todies defend a tiny patch of forest.

They're real stay-at-homes,
rarely leaving their territory

and never leaving the shelter
of the forest.

They feed by snatching insects
off leaves,

flying no more than a few yards
on short rounded wings.

Is it conceivable that this tiny
bundle of feathers could have flown



Well, the tody
may not have moved to Cuba.

Cuba may have travelled to the tody.

Millions of years ago,

before Panama existed, Cuba was
much closer to the continent.

At that time,
the tody could easily have fluttered

the short distance from America.

In Cuba's remote rainforests
live other creatures

that can claim to be ancient Cubans.

Their ancestors
joining the island before the tody.

This is an Eleutherodactylus frog.

It is one of over 60 species.

Like the Anolis lizards,
they've carved up Cuba.

Some live on the forest floor,
others along the streams.

There are even
Eleutherodactylus frogs

in the treetops,
living amongst the air plants.

You could argue that the todies may
have flown to Cuba

and that these small frogs
may have survived

a long sea journey
aboard a raft.

But scientific evidence suggests

that they were early pioneers that
hopped aboard 70 million years ago.

They have one big advantage
as pioneers.

Their tadpoles
don't need fresh water.

In less than 20 days,
the embryo transforms

from a few cells to a miniature
adult inside its transparent sphere.

This remarkable adaptation allowed
the frogs to live far from water.

These small frogs emerged
from their eggs

to colonise Cuba, from the treetops
to the forest floor.

Luis Diaz is the Cuban authority
on Eleutherodactylus frogs.

He and his colleagues
have discovered new species

in the last few years.

The most remarkable of these
was found as recently as 1996.

They live in the leaf litter
on the rainforest floor.

To find them,
you have to kick up a bit of a fuss.

The creature has
a very Cuban distinction.

In a family of small frogs,
it is the smallest.

In fact, it's the smallest
four-legged creature in the world.

This is an adult.

It's a third of an inch long.

The frog fits
comfortably on a thumbnail.

At this size,
a female can only produce one egg.

These frogs may have reached
the limits of miniaturisation.

Cuba's journey
didn't start 70 million years ago

when the frogs joined.

It was on the move before then.

Going back in time, Cuba was not
in the Caribbean, but the Pacific.

Could any animals have lived on Cuba

as it moved
through the Pacific Ocean?

For part of that journey
Cuba itself may have been submerged.

So the seas are the most likely place
to look for an animal whose ancestors

may have prowled the rocky shoreline
of Cuba around 80 million years ago.

The Goliath grouper
lives in rocky canyons and caves.

Today, it can be found in both
the Caribbean and Pacific,

so its ancestor might have patrolled
Cuban Pacific waters long ago.

It ventures out at night onto
the sandy plains of the sea floor.

It has an epicurean's taste for
lobster, but a glutton's appetite.

This Goliath grouper
weighs 440 pounds

and so a four pound spiny lobster
is just a bite-sized snack.

A grouper this large
can consume many lobsters in a night.

All big groupers are females,
as the males change sex as they grow.

The mouth on a six foot long female
is over a foot and half across.

Plenty of room for another lobster.

The ancestral Goliath grouper
may have lived in Cuban waters

millions of years ago,

but could the ancestors of any
Cuban land animals have lived there?

We can never be sure,
but a bird might have.

Flamingos are strong flyers
and have an ancient heritage.

There are fossils
from over 50 million years ago.

Ancestral flamingos
could have colonised

the muddy shores of an ancient Cuba,

in the periods
when it was above the sea.

Today, Cuba is home
to the largest colony

of Caribbean flamingos in the world.

Over 100,000 birds.

They nest close together
in a remote part of the coast.

FLAMINGOS BICKER

They seem to need the company

of other flamingos,
but still bicker over space.

The rich thick mud
is a great benefit to the flamingos.

It stops predators from approaching
the colony and it provides

the raw material for the nests.

But it also clogs the feathers
of the nesting birds.

The nesting flamingos
have a strict daily routine.

They sit during the heat of the day
to protect the eggs

from the tropical sun.

Then, as the day cools, they gather
into groups and fly

to the nearest fresh water
to drink and bathe.

This could be an image
from the distant past.

A daily routine that may have
taken place millions of years ago.

If there were land animals on
Cuba over 80 million years ago,

they may well have been flamingos,
though we may never know for certain.

But no land animal could lay claim
to the title of the oldest Cuban.

That must go to a creature

that could have visited
primordial Cuba.

When it was still being created

by the forces of the Earth,
over 600 miles out, in the Pacific.

Cuba then would have been a raw,
new island with little vegetation.

But its remoteness
and lack of land animals

would have suited
this possible first wild Cuban.

For it would have required
only a sandy beach.

Cuba was born 100 million years ago,

but there would have been turtles
then, as there are today.

For these marine reptiles
have a most ancient lineage.

Female turtles only come ashore
to lay their eggs.

Dry land is not their world

and they're clumsy
and uncomfortable here.

The whole visit
takes little more than an hour.

And then the turtle
returns to its world -

the sea.

But a brief visit just like this

may have been the very first life
on Cuba.

The story of wild Cuba
runs for 100 million years.

In that time, as the island moved
from the Pacific to the Caribbean,

many creatures have arrived
on its shores.

Today, their descendents live
alongside more familiar Cuban icons.

But it is these unique creatures

that make Cuba
the wild island of the Caribbean.