National Geographic: Panama Wild - Rain Forest of Life (1996)

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National Geographic: Panama Wild - Rain Forest of Life (1996)

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It appears out of the dawn of time...

...a creation of the sun,

caldron of life.

This is the tropical forest

nature at her most extravagant.

Sustained by the partnership

of animal and plant,

it has produced more than

half the species on earth.

It is a sea of green... seemingly

spellbound... changeless.

But look again.

Behind the green curtain are

countless battles for survival.

Into this complex world has come

a rare breed of adventurer.

Scientific knowledge is the treasure

they seek,

and to find it, they're not afraid

to go out on a limb.

This is a place unlike any

other in the world.

Panama's Barro Colorado Island,

known as BCI to the scientists

who journey here.

A protected realm in the middle

of the Panama Canal,

BCI is home to the Smithsonian's

Tropical Research Institute.

Scientists come to this island

from all over the globe

to unravel the mysteries of life

in the tropical forest.

It is an adventure beyond

the reach of one person,

or one lifetime.

BCI's a very special place for me

just because the more I come here,

the more familiar I get

with the island.

It's just home, it's comfortable,

it's exciting.

I think Barro Colorado Island

offers for me a lot of things

that I would not find

in any other place.

It's a really highly diverse forest,

the research facilities are

just fantastic,

you come there, you go out and

do the work,

and Barro Colorado Island

is protected

so that your work is not

destroyed at all.

I discover things.

In the tropics you may be a person

who's discovered something

that not a single human being

in the history

of the world has bothered to notice.

Here unfolds one of nature's

great puzzles.

How does the tropical forest

manage to support

such a remarkable community of life

and sustain itself at the same time?

One thing is certain,

at the heart of it all are the trees

A single tree, as it drives

towards the light,

affects the lives of countless

creatures.

But life is a struggle here

for every creature

and the odds that any one seed

will grow into a Titan are

astronomical.

It takes luck and strategy to

make it to the top.

For people, getting to the top

always requires some special

precautions.

Biologist Deedra McClearn

has learned to seek

the forest's answers on

its own terms.

Even if it means following her

slingshot all the way up...

...into the crown of one

of the forest's giants.

This is a dipteryx,

one of the great ones.

It rises head and shoulders above

the ocean of leaves around it,

more than a hundred feet tall.

From its majestic flowers will

come fruit,

and from the fruit,

perhaps an offspring

that will survive to take the place

of its parent among

a procession of giants.

Climbing has taught Deedra to

respect trees as individuals.

Since I've started climbing

I like dipteryx,

because it's a beautiful tree,

it's emergent,

it comes above all the rest

of the trees,

they often have great views,

and the wood is really hard

and solid.

I feel safe climbing a dipteryx,

chain saws won't cut down

a dipteryx.

I have a lot of different emotions

associated with actually

climbing a tree.

One of them is familiarity.

If it's a tree that

I've climbed before,

I feel comfortable,

it's a very satisfying sort of

feeling to make a good assent.

If it's a tree that

I haven't climbed before or

it's given me troubles,

or I'm worried about a branch,

then it can be very nerve-racking.

Deedra climbs into the canopy

to release a coati

a tropical cousin of the raccoon.

I know you.

She captures coatis just to let

them go.

I have caught you 15 times and

you always thrash around.

Just wait a second.

She's curious how an animal

who isn't a born climber manages

to survive ten stories up.

I think coatis are really

interesting

as climbing mammals because

they're not perfect.

They're kind of clumsy,

they're not graceful leapers,

they can't hang by their tail,

they don't have exclusively

manipulative hands

to grasp onto branches,

but they do really well.

One of the things that really

surprised me was that

they actually will jump quite

a far distance going down.

It'll launch itself into a tree

and it doesn't really know

where it's going to grab on,

it just, I think, assumes that

it'll be able to find something

when it hits that...

The coati has a lot of company

up here...

...with good reason.

The canopy is the forest's

powerhouse.

This is where leaves transform

light into the stuff of

life itself.

The canopy creates its own world,

with lands and waters,

prey and predators.

It overflows with flowers,

greenery, and fruit

food for all who can live

at these heights.

Earthbound for years,

scientists could

only guess what went on up here

- until now.

The canopy is the last frontier

on earth

and it's only been the last

that people have really gotten

up into the trees

and started looking at the insects

and looking at the leaves,

and actually there still hasn't

been that much mammal work up

in the canopy,

but it's a different life zone.

It's like going to the bottom

of the ocean.

You can't tell what's up here

from working on the ground

and it's different.

Bold researchers like Deedra

are proving how different

the tropical forest is from our

preconceptions of the jungle.

For one thing,

it is not always steamy and wet

Like many tropical forests,

BCI has a long dry season.

Food is now becoming scarce.

Even coatis,

who will eat just about anything

are hard pressed to

fill their bellies.

They gather under the majestic

dipteryx, waiting.

Now, when they need it most,

the tree will bear its fruit.

For dipteryx this is the beginning

of the long struggle to reproduce.

Howler monkeys gather in its crown.

Here is a banquet that will

stave off hunger for many.

The timing is crucial.

By fruiting during the dry season,

the dipteryx guarantees that

many will gather for the feast.

Oddly enough, the tree wants

its fruit to be eaten

even though each fruit contains

a seed

that could bring forth

the next generation.

But why?

All these capuchin monkeys know

is that food is nearly at hand.

And if enough of them arrive,

they could drive the howlers

from this nutritious meal.

What scientists have discovered

is the fruit is actually

an expensive bribe.

If animals take it,

they may carry the seed locked

inside far from the parent tree.

The further away the seed gets,

the better its chance of surviving.

With ripening fruit all

around them,

the canopy animals can now

afford to be finicky eaters.

Once they've had the ripest bit,

they simply drop the fruit

and move on to the next.

But this rain of half-eaten fruit

is of no help to the tree in

its quest to reproduce.

Its seedlings have little luck

of thriving here

in the shadow of the parent's crown.

Still for the animals waiting below,

it's manna from heaven.

The coatis eat only the sweet flesh,

they leave the seed intact.

But others are waiting in the wings.

Once the coatis have relieved

their hunger,

agoutis gingerly join the feast.

Agoutis are rodents;

they have teeth

and jaws designed to gnaw right

through the tough shell

and devour the seed within.

Squirrels, too,

relish the giant seeds.

Instead of creating

new dipteryx trees,

the seeds simply feed a host

of hungry visitors...

...even peccaries.

Satiated, the coatis settle

into some mutual grooming.

In evening's golden light,

butterflies and ants gorge upon

the remains of the feast.

It's been a good day for

all the animals,

but bad for the lordly dipteryx.

Its potential offspring lie

where they would have fallen away;

nothing has carried them away.

Has the tree's survival

strategy failed?

Is the next generation lost?

Is there no help under the sun

for the dipteryx?

Perhaps the moon can shed some light

on the mystery of the dipteryx.

Tropical nights weave

their own magic

and unveil a whole new cast

of characters.

Everywhere, there are bats,

conjured out of the dark.

Among the branches hunts

a marsupial, a marmosa.

Its prey is pint-size, like itself...

...a katydid camouflaged

unsuccessfully as a leaf.

Even while enjoying its meal,

the marmosa must be wary...

if it doesn't want to end up

as dinner itself.

Dipteryx seeds make a nutritious

meal for a spiny rat,

and a dangerous one as well.

Gnawing on the tough seed makes

enough noise

to attract the unwelcome eye

of a passing margay.

The tiny forest cat enjoys its meal,

until disturbed by yet another

denizen of the dark.

Only at night does Elizabeth Kalko

venture out on her own quest.

The Barro Colorado Island

she knows is very different

from the one most people see.

The night is a totally different

world from the daytime.

We are just exposed to a wonderful

orchestra of different sounds,

of many insects and frogs,

then you see the stars

through the canopy

and this is just an incredible

atmosphere.

And occasionally there are

bats fluttering by

and even touching you

with their wings.

The night holds no fear

for Elizabeth.

She is in her element,

and bats are her passion.

She hangs nets of fine mesh over

small streams, fishing for bats.

She believes bats are the unsung

heroes of the night,

vital to the survival of dipteryx,

and many other tropical giants.

That's a short-tailed fruit bat,

and although they are relatively

easy to get out of these nests,

one has to be very careful

about their sharp teeth.

Bats rely on forest trees for

food and shelter,

but they'll repay their hosts

as they make their nightly rounds.

Legs are free, whoops,

don't bite me, be nice, all right.

I don't think that bats are

really ugly,

I think that the misconception

that bats are ugly comes from

our very limited knowledge

about bats.

Most of the bats have very,

very, very pretty faces

and especially here we find bats

with beautiful facial stripes,

and colored ears,

and they actually have large eyes

and don't look ugly at all.

But a bat is much more than

just a pretty face.

Sometimes when I set mesh nets

and bats fly in,

they bring a fruit with them

and drop them in the mesh net

and so I can tell what kind of

bat has taken what kind of fruit.

I know what this bat had for dinner.

Let's get it out of

the mesh net here.

This is a fruit of the dipteryx.

And the bat has carried the fruit

in its mouth when it was hit

into this net.

It turns out that the fate of

our majestic dipteryx

rests upon the soft wings of

a little bat.

Drawn by the scent of ripe fruit,

artibeus bats hover over

the tree's canopy.

Yet death lies in wait

among these boughs.

Luckily the bat's ability to

"see" in the dark

using sound not only pinpoints

the fruit,

it warns it of the hidden boa.

Another bat flies, locates fruit,

carries fruit away

it tears it off the stem and

carries it away.

Still it's far too dangerous

to eat it here.

Only when it arrives at

a safe roost,

usually tucked under the fronds

of a palm tree,

does it stop to eat.

Unknowingly,

it has already performed a great

service for our dipteryx.

The bat has carried the fruit

away from the dipteryx,

beyond the reach of any diseases

or parasites that may plague

the parent tree.

Once the bat gnaws off

the sweet flesh,

it lets the seed drop.

Every night when the fruit is ripe,

artibeus bats make several visits

to our tree.

And each time they return to

the safety

of the same feeding roost

to enjoy their meal.

After each trip,

another dipteryx seed joins the

little mound forming just below.

Curiously enough,

in this heap of discards lies the

tree's best hope for a successor.

Morning's light has scarcely

revealed the half-eaten fruit,

when they are discovered by

an agouti.

Have the precious seeds come

this far, only to be wasted?

But the agouti can't possibly

eat all that it has found.

And what it does next adds

another piece to the puzzle

of how dipteryx manages to survive.

With the dry season continuing,

the agouti stashes the remaining

seeds for the hard times to come.

Much like a squirrel buries a nut,

it carefully hides them,

one by one.

Yet there will always be some

it doesn't need or simply forgets.

Unwittingly,

the agouti has now planted the

next generation of a tropical giant.

As the dry season on the island

gets worse,

many canopy trees actually

shed their leaves in a tropical

version of autumn.

For months, streams have been

draining water away.

And torrid heat continues to rob

the forest of precious moisture.

The remaining water collects

in ever shrinking pools.

More and more trees drop their

leaves;

it's a way to conserve water

and cut their losses as

the drought deepens.

As always in the forest,

there's an animal that's

found a way

to take advantage of

every situation.

It hides among the fallen leaves

disappearing in plain sight.

A caterpillar masquerading as

a dead leaf.

But there's no hiding from

the army ants.

Since many small creatures

disappear in the dry season,

army ants are forced to tackle

prey many times their own size.

They overwhelm them by sheer

force of numbers.

Treehoppers suck the remaining

sap out of plants.

But they're also under att*ck.

A mother defends her brood

from a wasp trying

to steal one of her larvae for food.

Each time the larvae wave their legs

calling out an alarm,

the mother treehopper strikes

back at the wasp.

By April, the dry season has

turned cruel.

Famine is only just kept at bay.

The buds from the balsa tree are

eaten before they can ever bloom.

The whole forest seems to

hold its breath...

...waiting for the rains.

Over eight feet of rain may

fall during the wet season.

The first good drenching triggers

an avalanche of change.

This wet new world is paradise

for creatures... water loving...

...and waterlogged.

Stan Rand, renowned frog man,

is used to working in a deluge,

but it does have its drawbacks.

When you wear glasses such as I do,

you don't see properly because

your glasses

get all wet from the rain on them

and then they get all steamed up

inside and you can't see anything.

Luckily, sight is not the primary

sense Stan uses in his work.

To truly enter the frog's world,

he must wait until dark

and find his way through

a landscape of sound.

What you hear are the voices

of all these frogs

and on a good night there can be

of frogs

all calling at the same time,

all audible from the same place.

Only the males call,

each in search of a mate.

To be heard and recognized

above all this amorous bedlam

is a challenge,

challenging, too,

for Stan and his students.

This is a young male pentadactylus

like all frogs they eat live food,

frogs and mice and insects

and probably small birds,

in fact, I know they eat small birds.

And he's got a dorsal secretion

that is really quite nasty.

He got me. One of their defenses

is this skin secretion...

Group walks away

For 30 years, Stan has lived in

Panama not far from BCI.

He's become totally attuned to the

ups and down of a frog's life.

He even understands why frogs use

different calls at different times.

There's a physalaemus male.

You can tell he's calling by himself

because he's just giving

a simple whine call... oow, oow.

If another male came in and

began to call,

he'd change his call adding

chucks to his call,

so he'd go, oow-chuck,

oow-chuck- chuck.

I can sometimes get him to answer

me as if I were another male...

See?

He went from going oow to oow-chuck,

oow-chuck, and now that

I've stopped talking to him,

he's going back to the simple

whines.

More frogs

Male frogs make the added "chuck"

sound to attract females.

The females can tell from the pitch

which male is the biggest

and strongest.

But male frogs have to think

twice about sounding off.

Because females aren't the only ones

out there listening to the chucks;

predators are too.

So any male frog that wants to mate

must gamble with his life.

And with other, bigger frogs nearby

a call can be a fatal attraction.

But for those who survive long

enough to mate,

it's a gamble well worth taking.

The male locks onto the female

in a mating embrace.

As he fertilizes the eggs,

he whips the fluid released

with the eggs

into a meringue-like

nest of bubbles.

These tiny frogs mate in

very shallow pools

at the foot of dipteryx

and other trees.

The bubbles help keep the eggs

moist and full of oxygen

and beyond the reach of aquatic

predators.

Sometimes several pairs will

cooperate in creating

a frothy nursery for their young.

Red-eyed tree frogs protect

their brood differently.

They live high in the canopy,

more at home on dipteryx's

spreading branches than in a pond.

They come down only when it's

time to mate.

Then they must get their young

close to water.

The males descend to

the lower eaves of the tree,

where they call to

the larger females.

After mounting the female,

the male hangs on tight.

She's off on a search for just

the right place to lay her eggs

a leaf overhanging

a small forest pool.

Location is critical

if it's too low,

her brood could be washed away

by the next storm.

Sometimes the eggs are laid

as high as 30 feet up.

The eggs are encased

in a jelly-like mass

a gooey aquarium in which

they'll develop into tiny tadpoles.

Only then will they drop into

the pool below.

The young frogs rush to develop.

And none too soon.

A vine snake... three feet

of elegant death.

In just four days the eggs have

become recognizable tadpoles,

but they're not ready to take

the plunge yet.

Even so, they may not have

the luxury of waiting.

At this stage,

the tadpoles can hatch.

But in just a few more days

their tails will be much longer,

allowing them to swim better.

And once they're in the pond,

they'll need to be good swimmers.

Fish will find the premature

tadpoles easy pickings.

It's a deadly dilemma

risk the snake's bite...

or leap into the waiting mouths

of the fish below.

As if the fish weren't enough,

the tadpoles must contend with

this monster in miniature.

A dragonfly nymph,

a youngster itself,

is one of the fiercest creatures

in this realm.

But there will always be some

who sidestep instant death and

live to return to the trees.

Despite all appearances to

the contrary,

even the dragonfly nymph will

be transformed someday soon

and take to the tropical air.

Waking to a misty morning is

an island wrapped in enchantment.

The rains have cast their spell.

And in the soil, the seeds of

our dipteryx await a rebirth.

But before that can happen,

the forest must change once more.

A carpet of forest litter,

preserved in the dry air

now moisture melts it away.

In just a few days,

the nutrients locked away

in the dead leaves will be

restored to the living.

Fungi and molds course over

the withered remains.

Fungi are the middlemen,

mining the bodies of the dead

for riches which they supply

to the living.

Here everything is recycled,

as a new generation rises

from the moist earth.

The seedlings respond in rhythm,

spreading their leaves to

catch the daylight,

folding them at dark.

Young vines grope for support.

They've traded strength for length,

and need help to climb

towards the sky.

But wherever they grow,

they can't escape the hordes of

hungry mouths that surround them.

To protect themselves from

being eaten,

many tropical plants lace their

foliage with poisons.

But these new leaves haven't

had the time to mount their

chemical defense.

Yet in the tropics,

poison to one is a treat for another

There's always some insect

that can find an antidote to

a plant's toxins.

And from then on,

it will be the only one they eat.

Leafcutter ants have found

another strategy.

An army of workers seeks out

only nontoxic plants

any and all they can find.

All herbivores are living

recycling plants.

They absorb just a small fraction

of what they eat.

The rest they return as manure

rich fertilizer that feeds

the growth of the forest.

Unless if gets h*jacked by

a pair of industrious dung beetles.

A monkey dropping is a mother

lode for the dung beetles,

who fashion it into a ball,

a combination pantry and nursery

for their young.

They roll their stash away,

looking for a place to bury it

among all the new growth.

A baby dipteryx enters this

complex and competitive world.

It started life as a tiny flower

in the canopy,

where it was pollinated and

ripened into fruit.

It was carried away in the claws

of a bat,

who ate its flesh,

and discarded the seed.

It was buried alive by an agouti,

and has lain in wait for

the rains for months.

Now, its time has come!

Only one in a thousand ever

gets this far.

The huge seed stored enough energy

to unfurl a giant among seedlings

nine inch tall, with lots of green.

Lots of juicy green.

But it is not a delicacy.

Not even a food of first choice.

But when other juicy edibles

become scarce...

...baby dipteryx does end up

on the menu.

The parent tree has spent centuries,

growing hundreds of feet and

preparing millions of fruit,

so at least one offspring will

survive to reach the canopy.

Yet all that effort can be

gobbled up in seconds.

It will never survive being

stripped bare.

And even those who remain intact

need luck to prevail.

They must have light to live.

And light is hard to come by

on the forest floor.

Each and every ray must penetrate

layers of foliage to reach

a seedling below.

Animals can search out light,

but the seedlings, rooted in place,

must wait for the sun.

They make do with sun specks that

flicker over the forest floor,

illuminating them for

just minutes each day.

Even if it gets its moment

in the sun...

...the fall of a single leaf

can seal a seedling's doom.

A new day in the forest sometimes

brings disaster.

If a new tree is to thrive,

another must fall.

For the plants that have struggled

to survive in its shadow,

perhaps for decades,

this is a reprieve from

a dark prison.

A light gap has been torn

in the fabric of the canopy.

It has been centuries since

this spot saw broad daylight.

For seedlings starved for the sun

it is a chance to grow and flourish.

A race for the life-giving light

has begun.

There will be winners and losers

as each plant tries to crowd

out its neighbors.

Into the new light comes

another creature,

biologist Phil Devries.

Phil studies the world of

the light gap

and he's discovered some astonishing

relationships here.

Since I've been a small child

I noticed plants and

I noticed insects.

I like being in nature and

I like forests a lot.

I can think of nothing more

enjoyable

than being surrounded completely

on all sides

and I literally mean up, down,

any direction

with life and that's what being

in a tropical rain forest is

all about.

His love for this forest world

is neatly matched to his quick eye

and insatiable curiosity.

I observe as much as I possibly can,

and effectively what

you're doing is you're asking,

"Hello organism,

what are you doing for a living

and who do you interact with while

you're out here doing your duties

as a butterfly or an ant or

a lizard or a plant?"

I can use butterflies literally

to move around in the forest

and tell me what

the vegetation is like.

Phil has uncovered a light gap plant

called a croton

that's developed an unexpected

relationship with

two different insects,

an ant and a butterfly caterpillar.

Croton provides sugar secretions

which attracts ants to

little nectaries,

and the ants when they're

on the plant...

...deter herbivores,

that is insects that eat leaves.

The plant actually uses ants

to guard its vulnerable leaves

bribing them with a sugary nectar.

The ants keep away any insect

that might do their meal ticket harm.

However, this is really what

I'm looking for.

It's an herbivore as well,

but the ants don't bother it

because it produces sugar

secretions of its own.

The butterfly caterpillar uses

its sugar secretions just

as the plant does

as a tasty bribe.

It keeps the ants well-fed in

exchange for their protection.

Back to ants & caterpillar

The funny thing about this

butterfly caterpillar is that

it bribes these ants with

a sugar secretion

and the ants act like guard dogs

and help protect it from

it's own predators.

In addition to producing sugar

secretions for the ants,

this caterpillar has another trick

that's even more magic.

Phil has made another remarkable

discovery.

These caterpillars can actually

sing.

To capture this amazing talent Phil

has designed special audio

equipment to record its calls.

This gear I have here is

an amplifier and a very,

very sensitive microphone.

I use this to listen to well,

basically, sounds that nobody

else can hear,

and I'm listening to this

caterpillar singing at the moment.

And how these caterpillars produce

their songs are pretty interesting in that on the top

of their head there are long bridges,

and right above the head

there's a collar where there are

two little rods,

and the two rods b*at up and

down on top of the head,

and then the head moves in and out,

and these little rods have

little rings in them,

and what they do is they hit

the top of the head,

and then it's rasping back

and forth like a Latin American

percussion instrument...

Caterpillar on mic,

Phil's fingers move it to branch

I think it's fair to say,

without gloating too much,

I have the world's largest

collection of caterpillar calls.

Now let's see what happens

when we reintroduce this

caterpillar to the ants.

Upon its return,

the caterpillar puts its musical

ability to another surprising use

mimicking the calls of ants.

The ants respond as we would,

if we heard a cry for help.

They rush over immediately.

And help is always welcome.

Danger is never far away.

This guard ant earns its keep.

An assassin bug could skewer

the caterpillar and suck it dry.

But it's no match for the ant.

A parasitic wasp fares no better.

In the tropical forest,

every creature lives within

an intricate web

shifting always between harmony

and struggle.

The lesson that I've learned is

that it's probably just scratching

the surface of the number

of interactions that you have in

any light gap in the tropics.

The picture that emerges from

there is of staggering complexity

when you think about

how many species...

there are of plants in the tropics,

and insects in the tropics.

It's very humbling to realize that,

even though I know a little bit

within the context of

a tropical rain forest,

I know absolutely nothing.

This little dipteryx, of course,

also knows nothing of the complex

network of relationships

that have brought it into the light.

So far, it has beaten the odds.

And if its luck holds out,

it may someday become

a forest Titan itself.

Dipteryx, large and small,

is at the heart of

a glorious pattern of forest life.

Unveiling this grand design

remains the quest of the scientists

of Barro Colorado Island

a labor of love,

and a journey of many lifetimes.

Perhaps centuries from now,

the forest will still be here

and scientists will

still be working in

its green depths

when our tiny seedling finally

takes its place among the giants.
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