Original subtitles

Australia - a land of diverse and often extreme habitats,

with vast expanses of wetlands,

dense forests

and arid plains.

(Shrieking)

It's populated by an immense array of bird life...

..and many species found nowhere else in the world.

Among them, some of the most flamboyant...

- ..ear-splitting... - (Shrieks)

..and bizarre birds imaginable.

Successful breeding is critical

to the survival of their species.

They need to go to exceptional lengths

to find mates...

..and raise their young...

..giving the next generation the best chance of life.

This is the story of breeding season.

For avian life, Australia is a paradise.

There are more than 800 species of birds here.

(Squawking)

And over 370 of these are only found in Australia.

But birds of a different feather

don't always flock together.

Some prefer to live in the rainforest,

like the golden bowerbird, who builds

his U-shaped nest from twigs,

in the hope of attracting a female.

The galah is part of the cockatoo family

and can be found in open country

across mainland Australia.

Some, like the Cape Barren goose, thrive by the seaside

and can drink saltwater.

And many share their environment with humans.

But, wherever they live,

these birds have got their work cut out,

holding their territory against invaders...

..attracting and winning partners...

(Mating call)

..and safeguarding their chicks.

Far North Queensland is famed for its beautiful beaches.

And one stretch is named the Cassowary Coast...

..because it's home to one of the planet's

most extraordinary-looking birds, the cassowary.

This is a mature female.

Queensland becomes steamier and more tropical

as you head further north towards the equator.

And its lush rainforests are ideal habitat

for the cassowary which thrives on forest fruits.

Like the Australian emu and African ostrich,

she's a ratite, or flightless bird.

Her flat breastbone has no keel attachment

for wing muscles.

It's thought that ratites evolved

around 60 million years ago, in the Cretaceous period.

And she certainly looks prehistoric.

She's solitary and usually wary of humans

and can be hard to find in the forest.

And she's huge.

Over six feet tall and weighing more than 100 pounds,

like all female cassowaries,

she's bigger and heavier than a male,

as well as more brightly colored.

In the dark, dense foliage of the jungle,

the shock of electric blue on her throat,

the vivid turquoise around her head and eyes

and dramatic red wattle,

all clearly identify her as a mature breeding female.

Comparatively little is known about this species.

There are several theories about the purpose

of the curious crest on her head, called a casque.

Although it looks hard and horn-like,

it's actually leathery and pliable,

formed by a keratin shell

growing over spongy cranial bones

and enclosing a mysterious empty chamber.

Cassowaries are omnivores and feed on fruit, beetles,

insects, snails and even carrion.

One theory is that the casque helps them forage,

and serves as a helmet as they dig through

dense undergrowth.

It may also protect the head from falling fruit,

be used as a sound amplifier or even a weapon in disputes.

The casque continues to grow for life and could also

advertise a bird's status and age.

Like the cassowary herself,

the casque remains steeped in mystery.

This female has a home range that overlaps

and passes through that of several males,

who will each have their own territory

of almost three square miles.

It's August, breeding season for this big bird,

but she's already parted from her mate.

She recently paired up with this male and laid his eggs,

but that's the end of their time together.

Female cassowaries don't raise their young.

Instead, they leave it up to the male to incubate the eggs

and later on, care for the chicks.

She can have several partners

over a four-month breeding season

and she's already on the lookout for another mate.

The cassowary isn't the only Australian bird to have

parenting arrangements like this.

This is a male brush-turkey.

He's part of the megapode family,

literally meaning "large foot".

He also lives in the rainforest,

in Cairns, far north Queensland.

Brush-turkeys are very adaptable and can be found

all along the eastern coast of Australia.

By September, springtime in Australia,

the brush-turkey is hard at work preparing a nest.

He'll spend all day, every day,

scratching around in one spot on the forest floor.

He may stop for a quick feed on insects...

..but then it's back to work.

He piles up leaf litter, twigs and earth into a mound.

This will play a vital part in his breeding strategy.

He rakes up the layer of debris on the forest floor

with his strong legs and large feet

and adds it to his little hillock.

Then he turns over the existing pile

again and again, breaking it down into a fine compost.

If all goes to plan, this will become a warm nest.

He's an average size for a brush-turkey,

around 26 inches long,

but the mound he's obsessively working on

will end up being a whopping 13 feet wide

and between three and six feet high.

And it's got to be good.

Females roam around selecting multiple partners

and won't mate with him

if his mound isn't up to their standards.

So a lot's riding on its meticulous construction.

The brush-turkey is a relatively common bird

and there are already several females in the vicinity,

who have smaller, paler wattles.

They're regularly checking out his progress

and will wait until the mound is complete

before deciding whether to mate with him.

But, right now, this brush-turkey

is only interested in one thing...

..his mound.

While he's still working on his masterpiece,

he doesn't want anyone near it, male or female,

and sends out a warning

to any other brush-turkeys in the vicinity.

(Warning call)

Stay away!

In the elevated Atherton tablelands

of Northern Queensland, higher and cooler

than their often sweltering surroundings,

it's October and breeding time for a very exotic bird.

This is the Victoria's riflebird,

named after the British Queen,

but is known as the duwuduwu

to the Aboriginal tribespeople.

He's a bird-of-paradise.

A fairly small bird, at around ten inches long,

he has an iridescent sheen to his feathers.

His breeding season can last up to six months,

so he's got to keep his strength up

by eating fruits and insects

he digs out of the bark of trees.

Snack over, it's time to get back to business,

attracting a mate.

He's got a core area of between two to seven acres

where he spends most of his time.

Within that space, he selects a conspicuous vantage point,

like a tree stump, as his display area.

Having a good location to display in is all part of

his strategy to get the females interested.

So he's territorial over his posing post.

Usually, his stage will be under a gap

in the canopy cover, so that the sunlight can stream

a spotlight to reveal his glowing feathers

to their best advantage and then...

(Mating call)

..he blasts out his mating call.

It's loud and unmistakable.

This raspy cry is just to make sure

he gets the attention of any female that might be nearby,

before launching into his piece de resistance.

It's a dramatic, full wingspread display,

that shows as much of his plumage as possible.

Erecting his feathers

before throwing out his wings is part of the act.

And so is opening his beak wide

to show the bright yellow interior.

He keeps going,

hoping to pique the interest of a female.

And, finally, he's graced with an audience.

Unlike the male with his glorious plumage,

female riflebirds are a dull brown.

But after just a few seconds,

she loses interest and flies off.

It's thought the females may base their mating choices

on quality of display,

so perhaps this male needs to brush up his skills.

(Mating call)

While his display is impressive,

this is Australia, home of the fantastic,

so there's another bird that can win a showing-off contest

with the riflebird hands down.

The lyrebird.

Lyrebirds live in temperate, often wet woodland

in the coastal southeast of Australia.

This one has made his home in a forest outside Melbourne

in the southern state of Victoria.

They're clumsy fliers

and spend most of their time on the ground.

Both the males and the females are a reddish brown

and have powerful legs with long toes,

ideal for raking over the leaf litter and soil,

looking for food, such as cockroaches,

spiders and worms.

A male lyrebird will also use leaf litter and earth

to build a display mound to dance on.

He may have over a dozen of these in his territory.

At first glance, he may seem unremarkable.

But as mating season approaches

during the winter months,

the male reveals his amazing talents.

(Whistles and warbles)

28-inch-long feathers

fan out from his tail, which he drapes over his head

in a waterfall formation.

(Squawks and whistles)

A male will start getting his display feathers

when he's around three years old

and these get gradually longer every year

until he hits sexual maturity at around seven.

The more mature the male, the longer his tail feathers.

12 silvery fluffy feathers, bookended by two thick,

banded feathers called lyrates

and two long, slender median feathers

make for a show-stopping performance.

And if that isn't enough to thrill the ladies,

his song is one of the most extraordinary

of any creature on the planet.

(Warbles)

(Squawks)

(Whistles)

(Warbles)

The lyrebird can imitate almost any sound it hears,

including other birds and animals.

Captive birds have even copied man-made sounds,

like trains, camera shutters and car alarms.

(Squeaks)

As this male lives deep in the forest,

he rarely hears artificial noises

and instead he's woven the calls

of the other birds that he hears into his own song.

In all, he's included the calls of 12 other species.

The purpose of having such an amazing talent

for impersonation is unknown, but it's thought

that the more complex a song the male can produce,

the more attractive he is to females.

His phenomenal ability comes from a special voice box.

A bird's vocal organ is called a syrinx.

The lyrebird's is more complex than that of other

songbirds, which gives him extraordinary flexibility.

He sings for 20 minutes at a time,

for several hours a day,

until a female is attracted to him

and allows him to mate.

After copulation, he'll return to displaying,

to attract the next one.

There's a female nearby, but she isn't showing signs

of being impressed by his performance.

And now a rival male has barged into his territory

and is displaying to the same female.

Both female and male lyrebirds

are fiercely territorial,

with an average territory of

three to six acres.

The competition is on.

The resident male tries to chase the interloper out.

But he doesn't succeed in pushing him far away.

And they end up displaying within feet of each other.

It turns into a real talent show.

Finally, the resident bird manages to chase the invader

out of his territory.

But the female has seen and heard enough.

Today, she's not interested in either of them.

She puts on a show of her own,

with no mimicry, just her own beautiful song.

Meanwhile, in the forest near Cairns,

the brush-turkey has managed to breed

and now has a clutch of up to 24 eggs

buried in the depths of his mound.

His little hillock is now almost three feet high,

but he's still hard at work.

He's the sole custodian of these eggs.

Because the females move around

from partner to partner, it's impossible

for him to know whether the eggs in his mound

were actually fertilized by him or another turkey.

Regardless of their paternity,

he'll tend the mound for the seven weeks it takes

to incubate the eggs.

The heat caused by the composting action

of the plant material will keep the eggs warm.

Heat sensors in his beak enable him to determine

the temperature of the mound and he'll regulate it,

by adding or removing material.

He's aiming for a temperature

of between 91 and 95 degrees Fahrenheit.

At 93 degrees, there will be an equal division

between male and female chicks.

If cooler, there will be more male chicks,

if warmer, more female chicks.

He guards the eggs until it's almost time for them to hatch

and then it's all up to the chicks.

They must dig their way out of the mound

and fend for themselves immediately.

Brush-turkey eggs and chicks are a favorite food

for carnivorous lizards, snakes and wild dogs.

And it's not just animal predators who pose a threat

to the brush-turkey's successful breeding.

Rural gardens frequently back onto brush-turkey habitat

and the turkey's practice

of making enormous breeding mounds in people's backyards

can lead to these precious piles of compost

being destroyed.

A single egg only has a one-in-200 chance

of making it to adulthood, so the brush-turkey's eggs

have still got a long way to go.

Just as the female brush-turkeys don't have

any involvement in incubating or rearing their young,

neither do the much larger cassowaries.

And, back on the Cassowary Coast,

the female is far away from the eggs she laid this year.

With parenting being the responsibility of the male,

she's free to spend her time foraging.

These giant birds are generally very shy,

but this female lives close to a beach

frequented by humans, which is far from ideal.

But there are some good feeding opportunities here.

These beach almonds provide a useful source of protein,

along with the insects she eats in the jungle.

Next to the beach is a campsite and she's not afraid

to make use of the amenities here.

Cassowaries need to drink frequently.

Her legs have their ankle joint

equivalent to where humans have their knees,

so she can bend easily to reach the water.

She has clearly become used to the humans here,

but this isn't a good thing.

Beachgoers are warned not to feed the cassowaries.

It can be dangerous for such a large animal

to associate people with food.

Becoming accustomed to humans

can make the massive birds more aggressive.

Not only is she one of

the heaviest birds in the world...

..she's equipped with a razor-sharp, five-inch dagger

on her dinosaur-like inner toe,

which she can use to vicious effect.

A high proportion of documented attacks have been

perpetrated by birds who have been fed by people.

Which may be what's worrying these picnickers.

Whenever cassowaries come out of the jungle

in search of human food,

the greater the risk to their survival.

They're more likely to cross roads and be hit by cars.

The rate at which they're the victims of road accidents

is of grave concern to conservationists.

Cassowaries are classified as an endangered species.

Luckily, she gets back to the jungle safely

to look for the more typical items in her diet,

insects and, crucially, fruit.

Cassowaries are a called "a keystone species",

because of their ecological importance.

They're able to swallow fruits almost whole

and have what is known as a "gentle" digestive system,

meaning that the fruits are excreted

with the seeds still intact and flesh still on them.

Fruits stay in the gut for less than four hours,

but in that time the cassowary could move

to a completely different area,

distributing the fruit species more widely.

So the survival of the cassowary is vital

to the continuation of many other species.

In the mild climate of the woods around Melbourne,

the male lyrebird is still going strong

with his spectacular display.

(Whistles)

(Squawks)

(Warbles)

He'll spend four hours a day singing for another six weeks

until the end of the breeding season,

mating with as many females as he can.

These birds have a division of labor

that's found more frequently in the animal kingdom.

Unlike the cassowary, it's the female of this species

that will tend the egg and rear just one chick.

Although he's busy trying to attract more partners,

he's already had some success.

He's mated with this female,

who now has a very big job to do.

She's in charge of building the nest.

First on the list: Gather some nesting material.

She collects some moss, leaf litter, pieces of fern

and twigs until she's got enough to create a cozy nest.

She even uses the male's feathers to line it.

It's a matter of personal preference

as to where she sites her nest.

Some females make their nests close to the ground.

Whilst others choose sites high up in the trees.

Ten to 14 days after mating, the female lays her egg.

She just lays one a year, unless the egg or chick dies.

If this happens and it's early enough in the season,

the female can mate again and lay another egg.

Six weeks later, up in the cozy but dark little nest

in the tree, her chick hatches.

Now it's Mum's job to keep her hungry hatchling

supplied with food until it can leave the nest.

She must feed her chick every 20 minutes.

She spends large parts of the day gathering up grubs

and small insects, which she carries in her throat,

ready to feed to her young when she returns to the nest.

Because of the rigorous feeding schedule,

she will even venture out at night looking for food,

a time when she's most at risk from predators

like foxes and cats.

Four weeks later, the lyrebird chick is fat,

fluffy and healthy.

With his nest being so high up in a tree,

his wings need time to develop,

so he can fly safely out when he fledges.

He'll spend ten weeks in the nest before leaving.

Chicks in nests closer to the ground don't need to wait

for their wings to develop as much and will leave

at around six weeks to go and live independently.

While the female is tending to her hatchling's every need

the male is still putting on a performance,

but with a different purpose.

The males molt their tail feathers

at the end of every breeding season,

so he won't have his prize plumage for very much longer.

(Whistles)

(Warbles)

At this time of year, these displays are all about

defending his territory,

rather than attracting a mate.

Even when his tail feathers are gone,

he'll still live in the same territory.

He wants to keep exclusive rights to this area

for the next breeding season.

He'll attack anyone who dares to transgress his borders.

The other male in the tree has come uncomfortably close

to his patch, he may be challenging the resident male

to see if he can take over his territory.

The resident male responds

by making his display even more robust.

But it doesn't put off the intruder,

who gets even closer.

As things get more heated,

they move further and end up down by the nearby creek.

The resident male asserts his dominance by crowding

and charging the trespasser,

pushing him towards the edge of his territory.

Finally, he gets the rival on the run.

For now, his territory remains intact.

While the lyrebird is singing and dancing,

the male cassowary

has childcare duties to attend to.

Because, in stark contrast to the lyrebirds' arrangements,

it's the male cassowaries who make the nest,

incubate the eggs and look after the chicks.

His four chicks are already around 11 weeks old.

He'll stay with them for another six months,

teaching them to look for food and water.

They're striped for camouflage,

but, by six months, they'll lose their stripes

and become a uniform mousey brown.

They won't begin to get their distinctive vivid coloring

until they're around a year to 18 months old.

Then the chicks will leave their dad's territory

to establish their own.

The male lives in a forest that adjoins a house

and sometimes crosses the garden here,

bringing his chicks with him.

While three of them are robust,

one of them seems to be weaker than the others.

This little chick struggles to keep up.

She may be sick.

Infant mortality in cassowaries is very high.

Predation, diseases, habitat destruction

and road accidents all claim young cassowary lives.

Out of these four chicks,

it's likely that only one will survive to adulthood.

For now, their dad takes care of their every need.

It can be rainy and humid

in this tropical part of the country,

but, today, it's extremely hot - 86 degrees Fahrenheit.

Dad's brought his brood out here for the good foraging,

but now he needs to get them out of the sun.

When he decides to move on,

the sickly little chick falls behind again.

She may not make it to adulthood, but her father's

attentive care will at least ensure

she has the best chance of survival.

The family crosses the road back into the forest.

As they depart,

the female cassowary appears from the forest.

She may be the chicks' mother,

but she's free of parental obligation.

She helps herself to a drink.

Even though there's a chance

she may run into her ex-partner and chicks,

she won't take any interest in their welfare.

From the tropical north...

..to the temperate south,

Australia's birds are some of the world's

most singular and exotic.

At every stage of the breeding season,

they're hard at work.

The strenuous job of attracting a mate...

..defending a territory...

..building a nest...

..and tending to vulnerable chicks...

..are all fraught with danger and difficulty.

These vibrant, talented

and eccentric birds...

..all adopt their own breeding tactics

to get the next generation safely on its way.