01x05 - Forests

[bunniefuu]

Surely, one of the most remarkable animals
that has ever existed,

and certainly one of the most famous,
is a dinosaur.

Tyrannosaurus rex.

An animal to spark the imagination
for all of us.

What kind of an animal was it?

What did it look like? How did it live?

Now, scientific research has answered
such questions.

And not just about T. Rex,

but the other species
that lived alongside it.

And the latest imaging technology
enables us to bring them all to life.

[grunting]

[David Attenborough]
Planet Earth, 66 million years ago.

[roars]

[roars]

The skies are filled with flying giants.

In the seas,
monstrous reptiles patrol the depths.

And on land, dinosaurs of every kind,

all facing the struggle to survive.

[leaves rustling]

[groaning]

We now know so much about a world
that was ruled by the dinosaurs.

[roars]

[shrieks]

This is their story.

[Attenborough]
The forests in South America

contain some of the world's tallest trees.

They can grow
to a height of over 300 feet.

But there are animal giants here too.

[tree trunk cracking]

[dinosaur bellowing]

Plant-eating dinosaurs.

These are Austroposeidon.

They're 80 feet long.

And they have colossal appetites.

Their teeth are used not to chew,

but simply to cut.

A herd like this one can consume
ten tons of vegetation every day.

They prefer the tender, young leaves
that grow on the tips of the branches.

But if they find trees
that are even taller than they are,

they're not defeated.

[bellows]

They use their great weight
and their 8-inch-thick breastbone

to simply push the trees over.

Success.

But life in the forest is always a battle.

Especially when new space is created.

Plants race to claim the light…

And use every kind of method
to gain the upper hand.

The gap in the canopy is soon closed.

Over three-quarters of the world's land
is covered by plants and trees.

This prehistoric planet is a green planet.

[dinosaur growling]

Many different species of dinosaur
live in forests.

Triceratops,
one of the biggest in North America.

They can be 26 feet long.

The huge frills on their heads
are used for protection when they fight.

But plants have defenses too.

Poisonous toxins.

These are particularly dangerous
for youngsters.

This calf weighs only
a 50th of the weight of his mother.

[yelps]

And the plant's toxins
could make him very sick indeed.

But Triceratops have
a way of dealing with such poisons.

They use an antidote.

One source of it lies in a cave
to which they pay regular visits.

This youngster, however,
has never been in here before.

[huffs]

They have to find their way
along a passage

that, over many millennia,
has been eroded by an underground river.

They are now beyond the reach of light.

They can't see a thing.

The calf must stick close to his family.

[calf yelps]

[calf yelps]

But not too close.

[calf yelps]

[wailing]

Now, one wrong turn could be disastrous.

[wailing continues]

At last, the herd reaches
the place they need to visit.

This is the antidote: A special clay.

These are known as clay licks,
and they're visited time and again.

But someone is missing.

Where is her calf?

[bellows]

[calf yelping]

[parent bellows]

[yelping continues]

[calf grunts]

[bellows]

Luck was on the youngster's side.

Once he's lined his stomach with clay,

he too will be protected from the poisons
in the leaves on which he feeds.

Soon they will all head back
to the forest and daylight.

In fact, very little of the sun's light

reaches the floor of these dense forests.

In Patagonia,

the thick vegetation stretches unbroken
for hundreds of miles.

But occasionally, there are
mysterious clearings, like this one.

[dinosaur growling]

It's the work of a two-ton,
12-foot tall Carnotaurus. A male.

Clearing this patch
has taken him a long time.

And it needs constant attention
if it is to remain tidy.

It's a stage
on which he can show off to females.

All is ready, and he announces the fact.

[guttural calling]

His calls are low-pitched

and travel much farther
through the dense vegetation

than higher-pitched ones would do.

[calling continues]

At last, a female arrives.

She's bigger than the male
and more powerful.

Now, somehow, he must impress her.

And he may only get this one chance.

She watches him carefully.

If he is going to impress her,

he must do so
in the most extraordinary way.

He doesn't have huge antlers,
nor a spectacular tail.

But he does have a pair of tiny,
apparently useless arms.

And each has a ball and socket joint
at its base

that enables him
to move them independently.

Not today.

How could he have done better? Who knows?

For now, it's back to litter picking.

This is East Asia.

In these mountain forests,
autumn arrives early.

This is when many trees
produce their fruit.

And amongst the most highly prized
are the nuts of the Ginkgo tree.

A bonanza
for dinosaurs called Corythoraptors.

Although they have feathers,
they're flightless.

These have found
a particularly abundant fall of fruit.

But such gatherings can attract
unwelcome attention.

Qianzhousaurus,
the top predator in these Asiatic forests.

This is a female, over 30 feet long.

If she is to catch a Corythoraptor,
she'll have to get close.

There's not much cover here.

But her prey have still not noticed her.

[squawking]

[roars]

She has failed.

But then, most hunts,

throughout the history of life,
fail most of the time.

[thunder rumbling]

As the seasonal winds strengthen,

many of the trees in these temperate
forests start to lose their leaves.

Winter will be a time of hardship.

Nevertheless, a storm does create
a brief opportunity for hunters.

She's trying again.

She's less conspicuous in the gloom,
and the gusting wind is distracting.

[leaves rustling]

[grunts]

An 80-pound prize.

All the more valuable,
since winter is now closing in.

In the forests of North America,

there is an additional annual hazard
for forest dwellers.

[fire crackling]

Fire, started by a strike of lightning.

As it spreads, temperatures rise
to over 2,000 degrees Fahrenheit.

The flames rise
several hundred feet into the air.

[dinosaur bellowing]

Most animals flee.

But this Edmontosaurus
has a family to care for.

[bellowing continues]

She doesn't abandon them.

Now they must keep one step ahead
of the blaze until it burns out.

This may look catastrophic.

But remarkably, some plants must be burnt

if they are to complete their life cycle.

The intense heat is needed
to open the cones of the pine trees…

And release their seeds.

And only a few hours
after the fire has passed,

animals begin to return.

Beetles are among the first.

They start to lay their eggs.

When they hatch,
the larvae will be the first to feast

on the near-limitless supply of dead wood.

This Atrociraptor is an opportunist.

Quick to return
when there's food on offer.

And there's something else
to be gained here.

Smoke is an insecticide…

And it can help an animal
to get rid of its parasites.

But you do have to be careful.

[growling]

A two-ton ankylosaur.

It also finds something worth eating
after a fire.

Charcoal.

It will bind with many of the plant toxins
in its stomach and neutralize them.

[bellows]

The female Edmontosaurus
is leaving the forest.

[bellows]

Against the odds,
she's led both her babies to safety.

[bellows]

They will have to find new pastures
until the forest plants recover.

Even where fires are rare,
trees do not live forever.

And after they die, they become food
for a very different kind of organism.

[insects chirping]

At night,
some of them become eerily conspicuous.

Down on the forest floor…

Fungi appear…

And start to glow.

They produce their light by chemical
reactions deep within their tissues.

But why they do so is a mystery.

It may be
because the light attracts insects,

which then help
to spread the spores of the fungus.

Here, in central Asia,

the nighttime forest
is filled with strange sounds.

[snoring]

Giant sauropods are asleep.

There are air sacs in their head and neck,

which reduce their weight
but also amplify their snores.

But not everyone is asleep.

For smaller creatures, it's safer to be
out in the darkness than during the day.

These Therizinosaurus
hatched just six months ago.

Barely three feet long,
they are only a tenth of their adult size.

Their claws may look like daggers,
but they're used more like salad servers…

Because these are plant eaters.

This forest, however, has all kinds
of food if you know where to look.

Honey.

It's dripping from a bees' nest
up in the branches.

Bees usually build their nests
beyond the reach of ground dwellers.

[bees buzzing]

But this one is lower than most.

And it's too good to miss.

[grunting]

[bees buzzing]

[grunts]

Unlike most dinosaurs,
young Therizinosaurus can climb.

Although they're not exactly experts.

[grunting]

[bees buzzing]

Angry bees produce a Mexican wave
to warn intruders to keep away…

Or suffer the consequences.

[squawking]

[squawks]

An adult Therizinosaurus.

It's huge, nearly 30 feet tall
and weighing five tons.

[bees buzzing]

Nothing the bees can do deters this one.

At last, a little treat.

And a few more stings.

[dinosaur bellowing]

Even by day, it's still dark
in the understory of the dense forests,

such as this one in Europe.

Animals of any kind
are difficult to distinguish.

Yet, they're everywhere.

Telmatosaurus seldom breaks cover.

And equally inconspicuous…

Zalmoxes.

The last
of a very ancient dinosaur lineage.

This forest
is one of their few remaining strongholds.

Seven inches tall, baby Zalmoxes are
no more than snacks for many predators.

But snacks are nonetheless worth eating…

So they have to be cautious.

[Zalmoxes yelps]

Hatzegopteryx stands 15 feet tall.

It is, in fact, a pterosaur,
a reptile with wings,

that here, as it st*lks through the trees,
it has to keep tightly folded.

This forest, so rich in small creatures,
is one of its regular hunting grounds.

It stands
on the southernmost edge of Europe.

This is the heaviest animal ever to fly,

and there is nowhere else here
where it can open its gigantic wings,

which are over 30 feet across.

Many of the forest's permanent residents
regularly come down here…

Because the plants are coated
with sea spray

and are a welcome source of salt.

Here, sauropods can meet one another,
renewing family bonds…

And creating new ones.

But for Hatzegopteryx,
the beach is a launching pad.

[squawking]

Now his wings will carry him
to yet another forest,

where life proliferates
more variously and more abundantly

than anywhere else
on our prehistoric planet.

To discover the science
behind the stories,

go now
to the Prehistoric Planet show page.