Original subtitles

- (Narrator): In the heart of Brazil,

the largest cat in the Americas reigns

over the world's largest tropical wetland.

This is jaguar country.

A magical land filled with natural beauty and great danger.

Where even an armored reptile,

the Jacaré caiman,

is no match for the powerful jaws...

(bird call)

...of this skilled hunter.

A few months ago, these plains were covered with water

for as far as the eye could see.

Now the dry season is well underway

in the northern part of the Pantanal.

It's late September, it hasn't rained in over five months

and the search for food forces animals out of the forest

to hunt and forage by the riverbanks.

For the all the creatures that live here,

it's one of the most stressful times of the year.

The riverbanks are bare...

Yet giant otters still manage to find fish in the shallow waters.

And while butterflies nibble on the minerals

left exposed on the sand bars.

Capybaras, the largest rodent on Earth, have to look harder

to find what's left of their favorite native grasses.

Even animals at the top of the food chain are feeling the heat.

Jaguars are an apex predator.

They have nothing to fear from any animal in the Pantanal.

Jaguars can weigh up to 290 pounds

and are 6 feet from tip of their noses

to the end of their tails.

(forest sounds)

(forest sounds)

And this female has found shelter from the intense heat,

along the banks of the Cuiaba River.

It's one of the largest tributaries

of the immense Paraguay River that feeds these wetlands.

The Pantanal is ten times larger than the Everglades.

80% of it is in Brazil.

Professional guide Ailton Lara makes his living on this river.

Deep in the protected territory

of the one of the Pantanal's northern state parks.

- (Ailton): This is a very good spot for jaguars.

Because there not many people around here.

It's a very remote place, far from the city.

The road access is not very good,

so it controls the number of people coming here.

- (Narrator): There's only one official road

into the far north of the Pantanal.

It's 90 miles long

and, on a good day, Ailton covers the distance

in about five hours.

At the end of the road is the small fishing village

of Porto Jofre,

the hub for Jaguar sightings.

- Yahoo!

- (Narrator): Even though Ailton's been tracking jaguars

for more than a decade, he still gets excited.

- There's a jaguar upstream the river,

so we're going to go straight to it now.

- (Narrator): In these parts, the Cuiaba river is the main drag.

It's 50 miles long and

breaks off into a maze of smaller rivers and streams.

Only twenty minutes into the search,

something catches their attention...

The big cats don't seem to mind the sound of the engine...

as long as the passengers stay in the boat!

It's an adult male.

Ailton has seen him before.

He bears the scars of battles both old and new.

A broken tooth.

And a fresh wound near his whiskers.

Probably the result of a territorial dispute

with another male jaguar.

Whatever happened, there won't be any more adventures today.

With midday temperatures climbing above 104 Fahrenheit,

this cool cat is staying in the shade

The Pantanal is a jaguar spotter's paradise!

Seven animals per 40 square miles.

- This area has more than one hundred individual jaguars.

So commonly we see about one or two jaguars a day

but sometimes we see ten individual jaguars a day

in a very good day.

- (Narrator): Jaguars are solitary creatures.

Like most cats, they spend almost half of every day sleeping.

They are crepuscular and are mostly active at dawn and dusk.

Males and females only come together to mate,

and soon go separate ways.

The female raises her cubs alone.

This two-year old male is about ready to leave his mother.

Since he was 6 months old, she's been teaching him how to hunt.

Now it's time for him to test his hunting skills.

A hungry jaguar will eat just about anything that moves.

The young male has spotted a group of giant otters.

And they've seen him too.

Their loud calls alert the rest of the family.

(otters calls)

These are the world's largest otters

and the adults are over 6 feet long.

They're feisty animals that like to do almost everything in groups.

Their tight knit families are always watching each other's backs.

If you attack one, you can expect the rest of the gang

to fight tooth and nail, and never back down.

Jaguars are opportunists.

If a young giant otter strays from the group,

the jaguar might have a chance.

But giant otter parents are very protective.

The young jaguar knows he's outnumbered, so he moves on.

In the Pantanal, jaguars specialize in hunting caimans.

Caimans are powerful and aggressive fighters,

but underneath that tough hide,

there's enough tender meat to feed a big cat for several days.

- (Ailton): In the dry season when the water is at its lowest,

it's very easy for the jaguars to find food

because all the animals will be congregating along the river.

And the jaguars will be there as well,

because there is a nice riverbank.

- (Narrator): As the dry season takes hold,

the cold-blooded caimans congregate near the shrinking bodies of water.

Over five million Jacaré caimans live in the Pantanal.

That's about 100 per square mile.

It's the highest density of caimans on Earth.

Most of the year, they live in loose knit and peaceful groups.

Their cousins, the American alligator and black caiman,

are much more aggressive.

Near the riverbank, fish trapped in the shallow water,

are easy to catch.

As the dry season advances and the river recedes more and more,

fish are concentrated into the shallow water.

Life is good for the caimans.

Although they are not the biggest members of the crocodile family,

an adult male usually weighs more than 120 pounds.

While females weigh about half as much.

Males and females both need to eat a lot of fish,

and the occasional capybara.

But at this time of year,

caimans are thinking about more than just food.

They have mating on their minds.

The males have several ways of letting the females know

they're in the mood.

They groan, make bubbles

and bellow all at the same time.

The bubbles are made by low frequency sounds,

called infrasound, made with vibrations deep

in their lungs which humans can't hear.

These intense vibrations cause the water on their backs

to spray fountains of water into the air.

Some have been estimated to be 30 inches high.

Impressing a future partner is a competitive event!

The more spectacular the display,

the better the prospect of getting the females' attention.

Males try to breed with many females

and females can often mate with many males.

Therefore, a female can lay a clutch of eggs

that contain the genes of a number of different males.

It will be another two to three months before she builds

a nest to lay her eggs.

Although caiman females are devoted mothers,

more than 80% of their nests are destroyed by predators.

For now, it's still the courting season

and the riverbank resounds with their groans and bellows.

(buzz)

The dry and sandy shorelines of the Pantanal's northern rivers

also attract hordes of female yellow wasps.

(buzz)

They gather in numbers to collect mineral salts

exposed by the receding waters.

For these workers and their queen,

salt is a vital part of their diet.

They carry it back to their nest to feed their larvae

and the queen.

Their colony is mainly composed of females.

Males have a limited role.

Before the end of the season, a generation of males

is produced just for breeding.

When the dry season comes to an end, the males die.

Upstream, where the riverbanks are higher,

and the forest denser,

the young jaguar male is still on the lookout for a meal.

He's left his mother and if he wants to eat today,

he's going to have to make a kill on his own.

- (Ailton): Sometimes a young jaguar can be experienced.

If they have a good mother, so they can learn good tricks.

Jaguars are not picky eaters.

They'll eat deer, peccaries, snakes, monkeys, turtles,

frogs and anything else they can catch including fish.

These big cats aren't afraid of the water

and they can even swim with a kill in their mouths.

The young male makes his way down river,

drifting with the current.

It's the easiest way to avoid a dense thicket.

Back on the riverbank, he takes his time,

prowling, listening and watching for his next kill.

He spots a large caiman in the middle of the river.

The caiman isn't too far away for the young jaguar...

but caimans have good eyesight

and the jaguar could never close the gap before being spotted.

So he decides it's not worth it, and moves on.

Capybaras are a favorite meal and an easier target.

The river provides relief from the unwelcome attention

of flies and mosquitoes, and the heat.

They are unaware of the young male jaguar

on the opposite riverbank.

In the dappled sunlight of the forest,

the rosette pattern of the jaguar's spots

is excellent camouflage.

But out in the open it doesn't help.

Because of their poor eyesight,

the capybaras haven't spotted the jaguar yet.

But their sense of smell is well developed.

And when one of the mothers picks up the scent,

she nudges the young towards the shore, away from danger.

And the whole family slips off into the bushes.

This young male has already passed up a few opportunities

in his hunt for food.

At 150 pounds, he needs to eat at least 70 pounds of meat a week

just to maintain his current weight.

He needs to pick up his game if he's to survive

the dry season of the Pantanal.

A few miles downstream on a quiet tributary of the larger Cuiaba River...

...a yellow-rumped cacique stands watch near a nest.

The caciques have some of the best,

and most elaborate nest building techniques in the bird world.

They're social birds and breed in colonies,

on the same communal tree.

Some colonies contain as many as 250 nests.

The female doesn't just collect and stack sticks and twigs...

She weaves her nest, like a basket weaver,

from long strands she's pulled from reeds.

The nests are deep, large cocoon shapes which protect eggs

from the long beaks of intruders.

But building is risky work.

The females often become trapped in their own nests,

and sometimes, if they are unable to free themselves,

they perish.

And the male?

He's not much help,

not when it comes to building a nest.

He doesn't help incubate the eggs either,

or collect food for his mate...

or for their chicks.

But when it comes to sex,

the male cacique is a powerhouse.

And with a male to female ratio of 1:10,

most male caciques are kept busy.

In their spare time, while the females forage,

the males protect the nests and their territory.

Since he's left his mother, this young male jaguar has passed up

at least two opportunities to try to make a kill.

Now, he's starving.

When he spots a lone caiman...

...he knows it's his last chance.

And he takes it.

An experienced jaguar would sink his teeth into the caiman skull

to puncture its walnut-sized brain for a quick kill...

But this somewhat inexperienced male loses his grip...

And the caiman rolls over.

So the jaguar tries a different tactic and attacks his throat.

He's lost his chance for a clean, fast kill,

like his mother taught him to do...

Now it's going to be a contest of strength and stamina.

Both animals are at home in the river.

But the caiman has one advantage over the jaguar.

It can stay underwater without breathing for up to an hour.

The caiman has a thick membrane that hangs across

the back of its throat and prevents water from entering

its lungs and drowning it.

And if the caiman can stay afloat,

and wait for the perfect opportunity for a quick roll,

it could turn the tables.

The tough caiman will not give up.

Neither does the jaguar.

The young male uses his strength to force the caiman underwater.

Just a small amount of water in the lungs would drown it.

The stress of the struggle takes its toll

and water enters the caiman's lungs.

Its body goes limp.

It's game over for the caiman.

This young jaguar has just killed his first caiman...

an amazing feat but his beginner's mistake cost him

a huge amount of energy.

He takes a short rest. His ordeal is not over yet,

he still has to haul the carcass out of the water.

He can't eat it in the water. The current is strong

and the area is too exposed.

His only choice is to drag the dead weight up the bank.

The river is too low, and the bank too high.

The young male drags his kill, searching for an easier exit.

Finally he finds the perfect spot

and heaves his prize to higher ground.

He takes another break,

then drags his prey into the undergrowth.

Now he can feast on his prize.

Not bad for a first kill without his mother's help.

As the sun sets over the Cuiaba River...

frogs begin to sing and join the night's symphony.

Birds contribute a few solos.

Jaguars roar to let each other know where they are.

And then... quiet.

Taking advantage of the cool morning air,

a red-footed tortoise braves the exposed open ground

and heads off in search of food.

Like most tortoises, it prefers fruit, but at this time of year

it'll eat almost anything, including carrion.

Red-footed tortoises travel in a zigzag pattern

all over their home ranges searching for food.

They can cover 22 yards...

...in an hour.

Damp mud is all that remains of this ephemeral pond.

But there are still some succulent leaves to be found.

They will provide essential moisture as well as food.

It could get lucky and find a stranded invertebrate.

As the day heats up,

it is time for the tortoise to head back to the forest.

It will follow its own scent trail to a well-hidden place

that will protect it from predators.

For tortoises, activities are limited during the dry season.

But for other species, this season is key

to their breeding success.

These large-billed terns take advantage

of the low water levels to establish large nesting colonies

on the sandy banks.

Some are still incubating their eggs.

Others hunt for food to bring back to their hungry hatchlings.

This impatient hatchling is getting hungry.

He makes such a racket he attracts the unwanted attention

of a predator in search of an easy meal.

A crested caracara several times the tern's size

is no match for this fearless parent.

Large-billed terns are very territorial.

They don't hesitate to attack.

Both males and females are quick to protect their offspring,

dive bombing, squawking loudly

and even defecating on the predator.

The scare tactics don't always work...

...but this time, for this noisy chick and its mother,

it's a happy ending.

Though its squawking isn't rewarded with a meal!

Back in the caiman pool, things are getting tense.

Two males are going head to head,

in a contest for territory, dominance and breeding rights.

A fight is a dangerous gamble they'd rather not take.

They'll first show each other how big and unafraid they are.

For now, it's a stand off.

The older male on the left has the advantage of size and experience.

On the right, the younger and slightly smaller male

shows no sign of backing off.

If he wins he'll move up the dominance hierarchy

and improve his chances of mating this year.

They're both patient...

until one makes a sudden move.

The old male hesitated for one split second,

just long enough for the younger one to clamp down

on his upper jaw.

A caiman's bite force is 270 pounds per square inch.

If this young male decides to use full force,

he could easily puncture the older caiman's eye.

Sparring caimans are often blinded.

But they have eyelid armor - a palpebral bone,

and can pull in their eyes to protect them from injury.

And that's not the young caiman's game plan.

He wants to pull the older caiman underwater.

But the wily older one is digging his claws into the sand,

and isn't budging.

There are no referees in this match of titans.

The females watching from the sidelines will be

the final judges of the males' performance!

The two have been locked together for over an hour.

And then, as suddenly as it began the match is over.

The older male jerked his head underwater and freed himself.

With his feet firmly on the ground,

he's ready to strike again.

While the challenger is at a disadvantage in the river.

So he quickly gives up, and swims away, defeated.

All this social stress will likely mean

he won't mate this year.

The old champ has defended his title - and his territory...

and when it comes time to mate,

the females will likely choose him.

High up in the sky, a flock of vultures circles

in search of their next meal.

Hidden in the underbrush,

the young jaguar feasts on the remains of his kill.

He can eat up to 44 pounds in a single day,

so a caiman this size won't last long.

Vultures patiently wait for leftovers.

After he eats his fill,

chances are he won't return to his mother.

For now, he needs to establish his own territory,

a challenge to be sure.

Because in a year or two he will be mature enough to mate.

For now, he marks an area in his mother's territory.

Finding his own will take time and experience.

Jaguars cover a large home range in their search for food.

And it usually overlaps with other animals of both sexes.

This region of the Pantanal is just one small section

of a long corridor that will perhaps one day be part

of a conservation program extending across

the whole south American continent.

- So the corridor starts from northern Argentina

all the way to Mexico.

The jaguar needs to meet different jaguars.

One jaguar from here, from the Pantanal, can cross the land

and go to the Amazon, from the Amazon they go somewhere else,

this corridor is very important for spread of genetics,

not to get inbred, otherwise they'll die out.

- (Narrator): Now that her "teenager" is establishing his independence,

the female is already on the move, looking for a new mate.

As for Ailton, he's still hunting for clues

of the magnificent predator's presence.

- We stopped here and something is really stinking.

Must be the leftovers from a jaguar.

It's a dead caiman. The leftovers from a jaguar.

By the stink, I can tell this caiman is here

for about two days.

- (Narrator): In much of its range the jaguar is known as the "yaguara".

It means "a beast that kills its prey with one bound."

Here, in the Pantanal instead of large reptiles killing mammals

as they do in places like Africa...

...a powerful feline has learned the skills to hunt

an ancient armored reptile.

This is one confident cat!