National Geographic: Panama Wild - Rain Forest of Life Page #3

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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 hijacked 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.

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