39x13 - The Bat Man of Mexico

[bunniefuu]

In southern Kenya lies
a remote desert kingdom,

home to a cast of remarkable
wild creatures.

They owe their existence
to an extraordinary relationship

between the largest animal
and the smallest,

a relationship of provision
and dependency

that has flourished
for millennia.

Together, elephants and termites
create water holes...

Animal oases
that are miracles of life.

This is the remarkable story
of a water hole in Africa,

the animals that created it,

and those that call it home.

Without water,
life has no chance

to join the desert in its dance.

For here, where sun
and wind hold sway,

when water comes,
it cannot stay.

This is Tsavo, one of Africa's
last great wildernesses.

It's an arid land,

yet rivers of sand
hint at something different.

...

It rarely rains,
but when it does,

a year's worth can fall
in just a few hours.

Most of it will run away,

destined for the Indian Ocean,

channeled by sand rivers

that flow for just
a few days each year.

They connect to
the mighty Galana,

which will carry
the rainfall away.

For the water to stay
and benefit wildlife,

requires the services
of the largest animal here,

and also the smallest.

Together, elephants and termites
create water holes.

For thousands of years,
their partnership

has transformed some of
the driest regions in Africa.

It all starts
with a termite mound.

The clay the mound is made of
is manufactured

by worker termites
deep underground

and then brought to the surface.

It is a sticky mixture
of organic material,

minerals, and water...

the perfect building material,

which will set hard
like concrete.

Compared to
the surrounding soil,

the clay is packed
with nutrients.

A termite colony might live
for decades,

but for our story,

what's important is
what happens to the mound

when a colony dies.

It can take years
for it to erode,

but elephants, rain, and wind
will eventually prevail.

Then all that is left

is another clay scar
in the landscape.

Every scar here
was once a termite mound.

They're a focus for elephants,

as the patches of clay
are what elephants love.

Tsavo's ancient red soils

are deficient
in the salts elephants need,

but termite clay contains them
in abundance.

Their constant excavation
means that,

little by little,
the site of the old mound

becomes a hollow
in the landscape.

When it rains, the fine clay
dust turns to sticky mud...

...and, for a family
of elephants,

that is irresistible.

Besides keeping them cool,
a coating of clay

protects against sunburn
and biting flies.

Once elephants start to wallow,

a water hole's future
is assured.

Each time a family visits,

it carries away
up to a ton of mud,

and so the hole grows.

After a year or two,
the young water hole

can hold enough water
to invite daily visits.

Within a few years,
what the elephants engineered,

with a little help
from the termites,

will become an oasis,

which all will visit
and some will call home.

A water hole can last a century,

but each year it must go through
a seasonal cycle

of decline and rebirth.

This is the story
of one of those seasons.

What sets it all off

is a direct hit
from a thunderstorm.

Then the paths
that the elephants made

funnel the water down
to the water hole.

Insects are the first
to move in.

Dragonflies pair up to lay eggs.

It doesn't take long for
the heavy lifters to arrive,

and some of them
carry passengers.

Tiny eggs arrive
on elephant feet.

Once underwater,

they hatch into baby killifish.

One character has waited months
for the water to return.

A lungfish spends
each dry season

asleep underground.

It's a living fossil,

a fish with primitive limbs
that breathes air.

And now there's water,

At this stage in its life,
the water hole is

well on its way
to becoming an oasis.

Seeds arrive in elephant dung,

and grasses and bushes
will follow.

For yellow-billed storks,

a full water hole heralds
a time of plenty.

Their beak snap is
the fastest reaction

in the animal kingdom...

but the lungfish is strong
and has powerful jaws.

And it's quite prepared
to bite back.

Compared to lungfish,

killifish live fast
and die young.

This female hatched from an egg
and matured in just two weeks,

but to have any chance
of spawning,

she must keep a low profile.

It's not an option for males.

To attract the attention
of a female,

they must fight and display
where they're most visible.

The female signals her choice

by allowing a male to approach.

Now that she's chosen him,

he'll dance just for her.

They must seize the day.

They have no way of knowing
how long the water will last

or what the future holds.

As the water hole matures,

it attracts different
characters.

Some come to bathe,

others to drink...

...and some to hunt.

For as long as there's water,

elephants are an enduring part
of the water hole's story.

The old mound is long gone,

but the minerals the termites
brought to the surface

are now dissolved in the water,

so the elephants
continue to benefit.

Their visits are vital,

both for what they take away
and what they leave behind.

Elephant dung is the foundation
of a pyramid of life.

A dung beetle can smell it
from a mile away.

He's one of the water hole
clean-up crew

who'll find the dung
by zig-zagging upwind

to stay in its scent plume.

He's last to the party,

but that's an advantage.

Others have already made
their dungballs.

He just has to steal one.

And for this little thief,

karma comes in the form
of a bat-eared fox.

Now that there's water and food,

the water hole attracts life
from the grasslands around it.

There's enough salt left
in the dung

for butterflies
to drop in for a drink.

They use a flexible proboscis.

It's a combination of sponge
and drinking straw.

A female slender chameleon

is a water hole regular.

The butterflies are more than
a salty snack.

They are full of protein,

and she needs to pack them in
while she can.

The water hole gives life,

and occasionally
it takes it away.

If the water level gets
too high,

it can threaten
living termite colonies.

These are soldier termites.

Their job is
to protect the colony.

But against water,
there is no defense.

With the galleries flooding,

the termites
are forced to evacuate.

Some soldiers stayed to the end,

but their sacrifice was in vain.

Young bullfrogs are
water hole big-mouths

and always on the lookout
for food.

The worker termites
are defenseless against them.

But the soldiers are armed
with formidable jaws.

There's a technique
to eating them,

which some get immediately.

Others have to learn
from experience.

The water hole is both larder
and nursery for bullfrogs.

Adults mate after heavy rain,

but it's a race against time.

In this ephemeral world,
the only certainty

is that the water hole
will eventually dry.

The female lays a sheet of eggs.

To survive in temporary
water holes,

bullfrog tadpoles,
like killifish,

have evolved one of the fastest
growth rates of any animal.

They hatch within hours,

and if the water lasts,

in just two weeks' time,

they will change into
tiny bullfrogs.

The water hole's wet season
is when most animals breed.

With male chameleons,
it's not dancing ability

that determines
who gets to mate.

It's a wrestling match.

One fall, and he's out.

The water hole's flush
of insects

has brought the female
into breeding condition.

She will mate just once

and lay her eggs
in a few weeks' time.

The water hole's inhabitants
don't yet know it,

but 30 miles away to the north,

there has been a decision

that will affect
all their lives.

Ten million red-billed quelea

have paused in their migration

and decided to nest.

The colony has synchronized
its nesting to the day.

In a week, the youngsters
will all fledge together,

and then they'll be on the move.

It won't rain again now,

and the water level
has started to fall.

The mound the termites abandoned

might not look much of a threat,

but to a dung beetle,
it's a mountain

whose slopes are covered
with pitfall traps.

A dung beetle is a walnut-sized
package of determination,

but he is also upside down
pushing backwards,

Dung beetles are nothing
if not tenacious.

And for an animal that
the ancient Egyptians

thought so powerful

that it rolled the sun
around the Earth,

this is a temporary setback,
not a crisis.

The termite mound might be
a magnificent testament

to insect social housing,

but in some ways,

it's more like
a pinball machine.

As the water recedes,

the banks it exposes

are what the chameleon's
been waiting for.

Now that there is no chance
of flooding,

she'll lay her eggs.

Her parental responsibility ends
with covering them up.

The eggs will develop
over the next few months...

Water holes are always
a focus for predators.

But, size for size,

there is one here who is
more powerful than any of them.

It's not a big cat,

but a spider.

The bullfrog tadpoles are about
to change into frogs.

They've just developed lungs,

so now they must come
to the surface to breathe.

It's what the water hole's
fishing spiders

have been waiting for.

A tadpole is 10 times
a spider's weight

and much stronger.

But if the spider can hang on,

she has venom on her side.

Away to the north,

the quelea have fledged.

Tomorrow, they will arrive
at the water hole.

It starts like any day.

But the birds are on their way.

Quelea are the most numerous
birds on the planet.

They visit the water hole

at the start of
the dry season...

...when the grasslands have just set seed.

A flock can drink


So great are their numbers
that it draws predators

to the water hole
from all over Tsavo.

It's rare that a lanner falcon
loses its grip...

...but one predator's loss
is another's gain.

The falcon won't give up.

Its technique is to apply
pressure to force a mistake.

Even a terrapin is tempted
to give it a go,

for the more the quelea drink,

the shallower
the water hole becomes.

A steppe eagle isn't quick
enough to catch quelea.

But he is quick to spot
an opportunity.

The terrapin has a quelea
by the legs.

But he's about to find out
he's bitten off

more than he can chew.

The odds of the quelea
being caught

were probably 1 in 10,000.

The odds of it escaping twice

are closer to 1 in 10 million.

But sometimes,
that's all you need.

As the land around
the water hole dries,

one of Tsavo's rarest plants
flowers.

Marsh lilies open at night

and last just a few hours,

so the bees are up early.

The water hole's sacred lilies
are different.

They spend the night closed
and then open by day.

Occasionally, they have guests
who have spent the night inside.

Quite why the tiny
Thumbelina frogs do this

is a mystery.

But bees love the lilies
for the pollen they produce.

So for the little frogs,

there is no chance of a lie-in.

The killifish have slowed down,

which gives a water scorpion

the chance it's been waiting for.

The fish have been spawning
for weeks,

and they are exhausted.

The water hole is now
the only source of water

for miles around,

and with so many using it,

will last just a few days.

Over time,
a water hole's popularity

can lead to its downfall.

If too many visit
or stay too long,

they destroy the vegetation,

and erosion follows.

What was once an oasis

can then turn into a dustbowl.

If more soil washes in
than the elephants remove,

then the water hole's fate
will be sealed.

For now though, the elephants
are keeping it open.

As the dry season progresses,

food becomes scarce.

No one can afford to let
an opportunity pass by.

An orb spider's web is
so strong,

it can trap flying birds,

let alone a plump baby bullfrog.

The web needs repairing,

which brings the spider
down close to the water.

But what she needs
to be aware of

In the space of a few weeks,

the water hole
has been transformed.

The only life that remains
is confined

to a few elephant footprints.

The lungfish must move now.

It uses its powerful jaws
and primitive limbs

to leave the water
in the same way

that its relatives did
when they colonized the land

hundreds of millions
of years ago.

It will bury down
to spend the dry season

safely cocooned in the mud.

The terrapin and water scorpion
will move on.

The killifish will die.

They mated until the end.

It ensured that
buried in the mud beneath them

is new life...

killifish eggs that will hatch

when the next rains come.

Close by, the lungfish
is aestivating.

Its metabolism has slowed
to a rate

just sufficient
to keep it alive.

It can survive like this
for up to five years.

The chameleon's eggs are safe
but entombed.

All are waiting for rain.

The water hole is now just
a clay scar in the landscape.

Without water, the flocks
and herds must move on.

Only the elephants
can stay longer.

Their matriarch remembers where
she dug for water years before.

And she can smell
where it lies beneath the sand.

Elephants prefer clean water.

No matter how thirsty they are,

the first dirty trunkful
is discarded.

In the dry season,

the role of clearing up
elephant dung changes hands.

Now termites take over,

and this benefits
a new cast of characters.

So, even in the dry season,
elephants and termites continue

to provide
for those that live here.

It is at the height
of the dry season,

when Tsavo is at
its most desperate,

that the Rainbush flowers.

How it predicts the coming rain
is unknown.

Perhaps it's a change
in pressure or humidity,

but it is never wrong.

The rain will release those
that are locked underground.

The baby chameleons
delay hatching

until the soil is soft enough
to dig to the surface.

After spending the dry season
underground,

the first thing they need
is a drink.

To begin with, butterflies
and hawk moths are their equals.

It will be next season
before a young chameleon

is large enough
to view them as food.

Until then,
it's all a bit overwhelming.

Better just to close your eyes

and pretend they are not there.

The termites' contribution
to the water hole community

goes largely unseen.

But once a year,
after heavy rainfall,

the mound comes alive.

These winged termites
are alates,

which have developed underground
and waited for rain.

They will disperse over Tsavo

to find mates

and set up colonies
of their own.

For those at the water hole,

they provide an annual feast.

The alates are rich
in fat and protein.

They are high-energy food
which is easy to digest.

A baby bullfrog still hasn't
worked out which end to go for,

but a wing is better
than nothing.

The alate hatch lasts
just minutes.

The water hole might last
a century,

going through seasonal cycles
of feast and famine.

In time, it will silt up,

But as long as there are
elephants roaming across Tsavo,

will stop on the scar
of an old termite mound.

The hollow they leave
will trap rain.

And in this land of termites
and elephants,

a water hole will be born
once again.

on this "Nature" program,