Life Story

There's a story that unites each of us with every animal on the planet.

It's the story of the greatest of all adventures,

the journey through life.

Animals have just one goal at the end of this journey,

to leave offspring. And every one begins its life

with an irrepressible instinct to survive and overcome the odds.

The drive and inventiveness of animals is breathtaking.

Every aspect of their behaviour,

whether it's spectacular or beautiful or simply extraordinary

is their way of meeting a particular challenge.

In this series,

we will see animals of all kinds striving to overcome the obstacles

that face them at each stage in their lives.

They will be strong.

Cunning.

And ingenious.

They will fight battles.

And will do whatever it takes to win a mate.

Each success leaves each individual one step closer

to leaving offspring -

the next best thing to immortality.

The journey through life begins afresh with every new generation,

as it has for countless millions of years.

It is life's great story.

I'm in South Africa, sitting beside a colony of meerkats, waiting

for this year's youngsters to emerge and start exploring their world.

Here they come. That's the adult.

They must check the coast is clear.

There's another one.

Ah, there's a baby.

Hello, little one.

We can't know what the future's going to hold

for this little creature.

Just as every one of our histories is unique to ourselves,

so this animal too will have its own story.

HE CHUCKLES

If one of these little creatures, indeed, if any animal

is to become one of life's winners by leaving behind offspring,

then a long and difficult journey lies ahead.

This is the story of life,

and for these little creatures, it's just beginning.

Good luck to you.

HE CHUCKLES

Many animals face their greatest challenge within days or even hours

of entering the world.

This is when they are smallest and most vulnerable.

The remote Orsted Dal Valley in Greenland,

scene of one of the most extraordinary trials that any animal

must face at the beginning of its life.

Newly hatched barnacle geese.

Their parents chose to nest on top of a huge tower of rock.

Such extreme isolation was the only way

to protect their brood from predators on the ground.

But now there is a price to pay.

Up here, the five goslings may be safe and warm,

but they have nothing to eat and they're getting hungry.

Like their parents, they only eat grass, and to find it

the goslings must first get down there, 400 feet below.

But they won't be able to fly for another eight weeks.

So they'll have to jump.

The father is restless.

He decides it's time for the family to leave.

BIRD HONKS

He calls to encourage them.

But they are so tightly bonded to their mother

that they will only follow her.

The parents both survived the descent as youngsters.

They're living proof that their chicks can make it.

The fluffy goslings are certainly light and well-padded.

But luck will play its part.

HONKS

At the bottom of the cliff, their mother calls for them to join her,

and instinct compels them to follow.

The gosling spreads its body and flaps its tiny wings

to slow its descent and lessen the impact of inevitable crashes.

If the first collision is belly-first,

it should survive the fall.

This chick jumps off the back of the cliff.

It's less of a drop,

but there's far more risk of getting lost in the crevices below.

The third makes another good jump.

But the fourth slips.

Plummeting down headfirst,

too close to the cliff, could bring disaster.

The third gosling is doing better.

Hitting the rock belly-first should prove a life-saver.

But still the tumble goes on.

ADULT BIRDS HONK

There is nothing its mother can do but follow it down.

CHICK CHIRPS

One last chick.

The perfect launch.

And a controlled drop.

This is as good a descent as it's possible to make.

Its parents are there to meet it.

A little dazed perhaps, but all in one piece.

One gosling, at least, hasn't made it.

And this chick appears to be in a bad way.

HONKS

At last, it responds to its mother's calls.

CHICK CHIRPS

The resilience of a barnacle goose chick is extraordinary.

But there are still chicks unaccounted for,

somewhere amongst the rubble.

The parents can't risk searching because they need to lead

their two survivors away quickly, before predators arrive.

A third one has made it.

But it needs to catch up.

Reunited.

Three out of five chicks have made it.

Without such a dramatic start in life,

it's unlikely any of them would have even got this far.

These chicks will face more dangers in the future,

but only two days old they've already survived

the greatest challenge of their lives.

A young animal significantly improves its chances of surviving

if it can grow fast, and few babies have more growing to do

in their first weeks than a humpback whale.

In just six weeks, this new-born calf must leave these nursery waters

off Hawaii and start on a 3,000-mile migration

to its feeding grounds in the Arctic.

For that, it will need to be strong.

Twirling at the surface

rapidly develops muscle strength and diving ability.

Before then, this one-tonne calf must double its weight

by drinking over 3,500 pints of its mother's fat-rich milk.

But the milk supply is limited.

Until its mother reaches the feeding grounds, she's fasting.

Humpback calves make such demands of their mothers

that females can only raise one every two or three years.

If the calf is to be ready for the migration,

then what they both need now is to be left in peace.

But here, the birthing season and the mating season coincide,

and that spells trouble.

Male humpbacks will pursue any females,

even if they are still nursing and so can't get pregnant.

These 40-tonne males, fired-up with testosterone,

pose a serious threat to any calf that gets caught up in the chase.

As the mother tries to outrun the males, the calf sensibly stays

as close to her as possible, to avoid being separated and lost.

As more and more males join the chase,

the mood becomes ever more aggressive.

Now there is a real danger of the calf being injured

by flailing tails and crashing bodies.

Eventually, the males become so pre-occupied

with fighting each other that the calf and her mother can escape.

Even if a calf gets away unharmed,

the ordeal can leave it exhausted.

The dangers from the breeding season

will only grow in intensity

and some calves will become so weakened

that they'll struggle to survive the coming migration.

Even the most formidable predators

are surprisingly vulnerable in infancy.

Here in Kenya's Maasai Mara, a lion cub has, on average,

only a one-in-five chance of surviving its first two years.

Which ones do so

depends on the strength of the pride

to which they belong.

For six weeks, this female cub

has been hidden away by her mother in the long grass.

But today, with her brother and sister,

she's going to join the creche at the heart of her pride.

Adult females provide the food and the first line of defence.

With at least four in her pride,

this cub should be well looked after.

All the lionesses have their own cubs,

who will be both playmates and future allies.

Under the females' watchful eyes,

she can practice her stalking, pouncing and fighting skills.

But there is one more family member to meet,

and perhaps the most important of all.

Her father.

Her ultimate defender.

Marauding rival male lions are a constant threat.

If they overthrew him, they would kill all his cubs

and father their own.

The security of the whole pride,

and this cub's future,

rests on him remaining strong.

But the early days of an animal's life are a very different prospect

if its parents do not support it.

This peculiar, almost alien scene

is in fact the emergence of a brood

of orchid mantids

from their egg case.

Mantids, like the great majority of animals, play the numbers game.

Having over 60 hatchlings

increases the chances that a few will make it to adulthood.

But during these first minutes, they are especially vulnerable.

They must quickly hide away...

and wait for their soft bodies to harden.

Within 20 minutes, they are transformed.

Now the immediate danger is from each other.

Mantids will eat anything that moves...

including other mantids.

Time to leave.

This tiny insect is now open to attack from predators

lurking in the undergrowth.

Whether an individual mantis survives or not