A young whale born late in the season
faces an urgent race against time.
And things are about to get rough.
Male giants dangerously vie for supremacy.
Hunters sweep in for the kill.
The allure of southern waters offers a feast for the taking.
But only the strongest can endure the epic journey.
Can the young calf overcome the odds
to make one of the greatest migrations on Earth?
The race is on.
In crystal clear waters off the west coast of Colombia...
..a young humpback whale draws his first breath.
His mother gently lifts her precious newborn to the surface.
The cool air triggers a deep instinct.
For the first time, he fills his lungs.
Each breath, a conscious decision to come to the surface.
He must quickly master this vital act.
For now, his colossal mother guides him up for air.
The first lesson in the life of every humpback whale.
He's been born to a vast, dark and salty world -
the eastern tropical Pacific, off the coast of Colombia.
It's an intimidating place for the little male,
but he won't have to go it alone.
For the first year of his life,
his mother will never stray from his side.
Add 16ft long, he's already a third of her length.
Despite her vast size,
he spent the final stages of pregnancy folded over
to fit in her womb.
It takes time to straighten out and strengthen his muscles.
He must master his huge tail, flukes and flippers.
Not the easiest of tasks for a calf born without the thick,
buoyant layer of blubber that would keep him afloat.
Until this layer builds up, the calf could sink and drown.
But his mother has already invested 11 months in his pregnancy,
so she's not about to let that happen.
She's over 50ft long and tips the scales at 90,000 lbs.
Her mass alone rivals a small herd of elephants.
He's got some serious catching up to do.
It will take him 12 to 15 years
to become one of the greatest giants on the planet.
To boost his piling on the pounds,
he has some of the world's richest milk on tap.
His mother's teats are close to the base of her tail,
so to reach them,
he must hold his breath and dive under.
As he nuzzles her underside, her nipple protrudes and squirts
milk into his mouth.
Day or night, he'll spend about 30% of his time feeding.
To begin with, feeding is a laborious affair
for the baby whale.
He can only hold his breath for a few minutes.
After a quick sip, he must paddle back to the surface for air.
Recharged, he returns to the milk bar.
He'll drink more than 43 gallons a day.
His mother's milk is 50% fat,
fuelling growth that is almost visible to the naked eye.
Baby humpbacks typically grow at a rate of more than four inches
a week, but this male is not typical.
Most calves here are born in early July.
It's now almost August.
He's been born a few weeks late.
It's a setback that could cost him dearly.
In November, he will undergo one of the longest migrations
on the planet - south, to the frigid waters of Antarctica.
If he doesn't bulk up in time and grow strong, he will never
survive the 5,000-mile journey.
This is where his mother fuelled her pregnancy.
Southern summers bring long hours of sunlight to the poles.
Algal blooms flourish in the abundant light, resulting
in an explosion of tiny shrimp called krill.
These two-inch-long crustaceans form the basis of the humpback menu.
With gaping jaws, the whales engulf giant mouthfuls of the shrimp.
One large mouthful takes in 5,000 gallons of sea water...
..and everything swimming in it.
The water escapes through the baleen plates
in their upper jaws - giant sieves trapping the food within.
It's a feast that's five months long.
Each humpback gorges on one-and-a-half tonnes of food
each day.
By season's end, they've gained several tonnes of blubber, enough
to sustain them as they head away from the frigid waters of Antarctica
and turn north.
Before winter arrives, they must return to the warm waters
of Colombia, where they'll breed.
It's a monster journey, taking six to 12 weeks,
covering 5,300 miles.
In June, around 1,000 whales descend on this patch of ocean
off the coast of Colombia.
The calf's mother was born in this same area.
She returns here every two to three years to breed.
Her newborn calf is small enough to be vulnerable to large sharks
and killer whales, so she's selected a very special nursery.
22 miles off Colombia's Pacific coast is the island of Gorgona.
A sheltered bay on its east coast acts
as a birthing ground for humpback whales.
Gorgona towers over 1,000ft above the Pacific, thrown up
by volcanic activity some 90 million years ago,
during the age of the dinosaurs.
The island is far older than whales themselves,
which first appeared in the oceans
around 50 million years ago.
It's entirely possible that whales have been visiting Gorgona's
waters ever since.
Thanks to its proximity to the equator,
its waters remain 23 to 27 degrees centigrade year-round,
providing a warm welcome for the whales
and ideal nursery conditions for their young.
The depth of the water in Gorgona's sheltered bay is perfect
for protecting young calves.
At just 65ft deep, it's harder for predators to sneak in and launch
a surprise attack.
Gorgona's waters attract other ocean migrants -
olive ridley and green sea turtles.
Like the humpbacks, they travel
over thousands of miles of ocean every year.
Genetic studies show that the green sea turtles come from birthing sites
on the Galapagos Islands, more than 800 miles away.
There are even some that have made the 5,500 mile journey from Hawaii.
Baby green turtles are drifters,
disappearing into the open seas
and riding the currents until they're about ten years old.
Then, as teenagers, some arrive on the reef off Gorgona and stay
here to feed.
Most of the green sea turtles won't breed here. They'll fatten
up for a decade or so before returning to where they were born.
Young green turtles are carnivores,
but as they mature, they switch to a vegetarian diet.
This adult female is eating algae.
She's one of the few green turtles that were born here.
At 3ft long, she is fully mature
and, unlike most of the other greens, she is here to breed.
She has recently mated.
It takes about 15 days for the eggs to develop inside her.
While she waits, she must eat as much as she can to ensure
her developing clutch gets the nutrition it needs.
She's not the only one fattening up in the bay.
The young male calf is doing well.
After a couple of weeks of piling on the pounds, his body
has filled out.
But as he gets bigger, he's faced with a new problem.
It takes a while for whale calves to master their buoyancy.
He seems to flounder back and forth towards the surface.
WHALE CALLS
His mother, hovering nearby, is neutrally buoyant and can hang
motionless for hours at a time.
Every time the calf tries to hover like his mother,
he drifts and rolls.
The only hope of getting a much-needed rest is to wedge
himself under his mother's chin.
Like all baby animals, he needs a lot of sleep.
Thanks to his mother's hydrodynamic design, he can nap any time
without losing her.
As long as he stays close to her, he's gently pulled
along in her slipstream.
It's known as echelon swimming,
and it means his mother does all the heavy lifting
while he conserves his energy for growing.
He now has only three months until he must take the mammoth
journey to Antarctica.
It's crucial the baby's big enough and has enough blubber
to survive the trip.
To ensure every calorie goes into his growth, his mother does
everything she can to prevent him
from expending any unnecessary energy.
Normally, mothers and calves spend half their time resting,
but unwanted visitors to the island make that a near impossible task.
Adult male humpbacks...
..with only one thing on their minds -
finding a mate.
By August, the waters off Gorgona are teeming with whales.
Up to 1,000 gather here every year.
Male humpbacks aren't as big as the females,
but at around 45ft, they're still huge.
And they are determined to throw their weight around.
With immensely powerful tails,
they're able to hurl their 30-tonne bodies into the air.
Whales breach for various reasons.
But on the breeding ground, male breaching reaches its peak as rivals
try to outcompete each other and impress the females.
WHALE SONG
But they also have a gentler way
to get themselves noticed while they're here.
Humpbacks sing the longest, loudest songs on Earth.
It's an exclusively male pursuit,
and incredibly, they manage to create sound without vocal cords.
Instead, the whales use special folds in their larynx which vibrate,
creating sound as air is pushed through them.
The notes are so powerful, they can be heard thousands of miles
away, echoing across entire ocean basins.
WHALE SONG
These epic songs last around 16 minutes and repeat on a loop
for up to 23 hours at a time.
Each new breeding season heralds a new song, specific to a region,
and every male in that population sings that same tune.
Every year, it evolves and changes.
Who composes it and how they all learn it is,
like so much of the whales' lives, a mystery.
The latest research suggests that the whales learn the songs
one phrase at a time,
in much the same way that a human gradually learns
a new language.
It was long assumed that the purpose of whale music was only
to attract a mate.
But scientists, using the same methods that have been used
to analyse bird songs, have discovered that whales use
different musical phrases for different purposes,
not only for mating, but also to identify themselves.
When one male approaches another,
they sing the individual phrases faster.
It's thought that by engaging in a sing-off, humpbacks
can determine which individuals are the strongest rivals.
What is known is that one singer quickly attracts other males.
The males form rowdy gangs that patrol the breeding grounds,
looking for available mates.
Females typically breed again only once their calf is at least a year
old, but that doesn't stop the males from moving in on the mother
with her newborn calf.
He's barely a month old and still totally dependent on her.
The largest of the males approaches.
Like all male humpbacks, he is smaller than the female,
but his behaviour is nonetheless intimidating.
It's extremely stressful for the mother and her calf.
Mothers and calves harassed by males must expend a lot of energy,
energy the calf should be using to grow and build fat reserves.
But worse, in trying to get close to what he sees as a potential mate,
the adult male risks crushing the tiny calf.
His mother tries to guide him safely out of harm's way, but her potential
suitors don't get the message.
The males become more boisterous,
hurling themselves out of the water,
demonstrating their incredible strength.
The calf wouldn't survive the impact of a 65,000lb male
crashing down on him.
Desperate to keep her calf away from the raucous males, the mother
is faced with a difficult choice -
move her calf further offshore, away from the safety of the bay's shallow
waters, or stay close to the coast and risk the males
injuring her baby.
Reluctantly, she moves further offshore.
The frantic encounter has taken its toll, depleting
the calf's limited resources.
Stressed and exhausted, he desperately clings
to his mother's side.
The calf is now adrift in 900ft of water.
This is far from ideal.
They may be away from testosterone-fuelled males,
but out here,
the potential for predation is far greater.
The biggest threat to any young humpback patrols these dark waters.
Killer whales.
They're not actually whales at all
but giant dolphins,
also known as orcas, devilfish.
They live up to their name.
They're the wolves of the sea,
pack hunters that, in some places,
work together to target the great whales.
They've even been known to bring down blue whales, the biggest
creatures on Earth, but baby humpbacks are a much easier target.
Their ruthlessly efficient technique is to separate a mother
from her defenceless calf.
The mother does her best to drive them off, aggressively slamming
the water's surface and lashing out at her attackers.
If the killer whales can separate them, they'll leap onto her calf,
pushing it underwater to drown it.
The orcas are fast and agile,
but moreover, have numbers on their side.
But help is at hand.
The male whales.
They close rank.
Humpback whales are known to demonstrate a remarkable ability
to help others.
They have immense strength and some very effective weapons.
Their tails contain some of the most powerful muscles on Earth.
A sideways slash is a clear sign of aggression.
And it works.
The killer whales slink off in search of easier prey.
This seemingly altruistic behaviour by humpbacks is well documented.
One has even been seen lifting a seal out of the water to keep
it safe from killer whales.
Another guided a human diver away from a hunting tiger shark.
After the dangerous encounter, the mother reverses course
and gently guides her calf back to the safety of the shallows.
Here, they're among the company of other creatures that flock
to Gorgona's waters.
Shearwaters are long-distance flyers that glide low over the waves.
Like the whales, they seek warmer islands on which to breed.
But for the rest of the year,
they can literally circumnavigate the globe.
Many will have fed alongside the humpbacks in Antarctica.
They're joined by resident frigate birds.
Frigates are amongst the most agile aerial predators, riding
the thermals to save energy while they look for fish.
Jumping tuna are a dead giveaway.
The fast, predatory fish drive smaller fish to the surface,
and the birds flock to the disturbance.
Once they've filled their bellies, the frigates return to their nests.
The noisy colony is dominated by males, showing off
with their extraordinary displays.
They inflate their throat sacs to try to attract a mate.
The males' balloons act as amplifiers for their peculiar songs.
Couples work together to build the nest and brood their single
chick for the first month or two.
Then the males hand over full child custody to the females.
The mothers lavish all their attention on the chick
for nine months, the longest period of parental care for any bird.
By September, many are almost fully grown and ready to leave the nest.
But before they take that final step,
they must get used to 8ft wings
that will soon carry them out over the ocean.
They won't develop the dark, glossy feathers of their parents
until they are mature enough to breed,
which won't be for another decade.
The frigate chicks thrive thanks to the rich waters off Gorgona.
The male humpback calf, now two months old, isn't faring so well.
He's become lethargic, allowing barnacles and whale lice
to colonise his head.
It could mean that his health is compromised.
All humpback whales have these hitchhikers.
This species of barnacle, a distant crustacean cousin of crabs
and lobsters, is unique to humpbacks.
Like the whales, they start out life as travellers -
tiny, free-swimming larvae that drift with the plankton.
When they sense a passing whale,
they attempt to latch on.
The more active and fast swimming the whale, the harder it is
for the larval barnacles to attach.
But the slowness of the calf has meant he's an easy target.
They've had time to secrete a powerful cement
and start to build a more permanent home.
In turn, the barnacles have allowed lice to take hold, clustering
around any scratches and scrapes where they can feed on his skin.
Animals that are sick or injured, with suppressed immune systems,
tend to have more lice than healthy whales.
And large infestations can damage a whale's sensitive skin.
It's a worrying sign that the little whale's health
has declined so dramatically since his birth two months ago.
He will have a tough time shaking his unwanted passengers.
It's thought healthy whales are able to keep their levels of lice
and barnacles low through breaching.
There are many reasons whales breach, including this pest control.
The vast weight of a whale slapping the surface is thought to knock
off some of the hitchhikers,
but the encrusted calf hasn't yet learned to breach.
He's seriously behind in his development,
and the clock's ticking.
The stress of the past couple of weeks
may have been too much for him.
He has just two more months before he'll have to leave
these warm waters and accompany his mother on the 5,000 mile journey
south to the Antarctic.
If he's to survive the perilous trip, he'll need to build up
his strength...fast.
His mother's job is to get him ready for the journey, but all she can do
is watch over him and keep up the supply of rich, fatty milk.
For the female green sea turtle,
fulfilling her maternal duties is much simpler.
Under the cover of a moonlit September night, she comes ashore
to lay her eggs.
Her slippers, usually paddles in the water, become useful shovels,
as she excavates a sandpit between one and two feet deep.
Her tail acts as a long ovipositor
to drop the ping-pong-ball-sized eggs into the nest -
on average, about 150.
The eggs are rubbery to cushion their fall.
With the clutch deposited, she'll carefully cover them up
before returning to the sea.
Her maternal duties are done.
It will take six to ten weeks for the eggs to develop and hatch,
and they will do so alone.
Further offshore, a solitary female humpback searches for a mate.
Typically, humpbacks have an interval of two or three
years between offspring.
Some females take a gap year between calves and choose to stay
in cooler Antarctic waters and feed year-round.
But when they're ready to breed again, they return,
and the males know it.
Boisterous mating behaviour reaches its peak in September,
three months after the arrival of calving females.
Timing is everything.
It's crucial that females get pregnant now so their calves
are born at the start of the season next year and have the maximum time
to grow before heading back to Antarctica.
With some females remaining in Antarctic waters, there are often
more males than females at the breeding grounds.
So the females that have made the journey to Colombia
can afford to be choosy.
She pec-slaps, waving her huge, 16ft pectoral flipper in the air
and then slapping it down on the surface.
The thunderous clap can be heard underwater throughout
the breeding grounds.
It's not long before several hopeful males gather.
To stand a chance of mating, a bull needs to impress the female,
demonstrating his strength and stamina.
So she keeps on the move, forcing the males to give chase.
This is the heat run.
Anything from two to 20 males might join in, all trying
to outdo each other.
Aggression is rife.
The males breach and slap the surface, making as much noise
as possible, trying to intimidate the others.
As their excitement cranks up, they start to lash at each other
with their tails.
Slapping their chins on the water is also a clear sign of aggression.
They even ram their opponents.
As the competition heats up, the whales' speeds increase,
eventually exceeding 12mph.
Gradually, smaller, less experienced or older males
drop out, defeated.
The last man standing is the cream of the crop...
..bearing the strongest genes
the female has selected to pass on to her calf.
What happens next is one of the humpback whale's
many great mysteries.
Mating has rarely been observed.
While she's receptive, the female may mate with several males.
So often, a single male stays by her side for weeks, trying
to keep competitors at bay.
He's known as an escort.
With a limited season in which to prove their worth,
the rest of the males can't afford to relax.
The offshore waters remain boisterous with potential breeders.
It's now October.
Sheltered in the bay, the barnacled calf and his mother have been able
to rest and recuperate for a month.
He is looking a bit more energetic and he's gained a little weight.
Even better, his increased activity has meant he's been able to dislodge
most of his unwelcome hitchhikers.
Whales shed their skin all the time, especially when they're growing.
Now that the calf is once again piling on the pounds,
he's replacing his skin cells faster.
As he loses his old skin layer, it's taking some of the barnacles
and lice infestation with it.
He's grown more than 15 inches in the last month.
Slowly but surely, the little calf is catching up.
The youngster nuzzles against his mother.
Calves usually rest above their mother's jaw to keep
them safe from attack from below.
He swims under, perhaps trying to dislodge some of his parasites
against his mother's bumpy chin.
Humpbacks are very tactile animals, and for the past 12 weeks,
mother and son have been in constant physical contact.
But slowly, that's starting to change.
As he grows, the calf needs to begin mastering the life skills he'll need
once he leaves his mother's side,
including learning
some of the humpback's more dramatic moves.
His mother demonstrates, and he tries to copy.
He starts with some of the simpler communication moves.
Pec-slapping and tail lobbing.
Confident at pulling off the basics, the young calf ups the ante,
attempting to master the most impressive humpback feat, a breach.
Slowly but surely, he manages to lift his head clear of the water.
The crash landing from a successful breach can be heard many miles away.
If the calf can succeed, he'll be a step closer to maturity.
This training also helps build up his muscles for his epic journey
south and has the added benefit of dislodging a few more barnacles
along the way.
As the whale calf grows, he gains confidence.
He's now three months old
and ready to start properly exploring his surroundings.
Below him, the reef teems with life.
The shallow waters receive plenty of the sun's energy
for corals to grow.
The whales themselves might significantly contribute
to the health of the reef.
When they defecate, their waste feeds algal blooms, which the corals
filter from the water as food.
These microscopic algae in their billions produce much
of the oxygen in the atmosphere.
As the algal blooms photosynthesise, they also remove carbon dioxide
from the air, so indirectly, the young whale is helping to combat
one of the world's biggest challenges, climate change.
By fuelling these algal blooms, whales might be responsible
for the removal of 440,000 tonnes of carbon each year.
The whale-fed algae then feeds plankton and small fish,
which in turn feed bigger ones.
It's a giant feast, partly fuelled by the whales.
By late October, there are signs of new life stirring in the sand.
Like a clockwork toy, a tiny sea turtle paddles with all his might.
And he's not alone.
More than 100 emerge en masse, swarming down the beach.
Most of the turtles born here are from the nests
of olive ridleys, a species that commonly breeds on Gorgona.
But among them is something very rare for the island.
A nest of green sea turtles.
There are only a few records of them breeding here.
While turtles and whales share their destiny in the ocean,
their strategies for success are polar opposites.
Whales produce a single infant at a time and invest
all their energy in helping it develop
until it can survive on its own.
Sea turtles play the numbers game, laying hundreds of eggs
and abandoning them to chance.
The odds are slim.
There are dangers at every turn.
It's a desperate race to the water before birds and other beach hunters
cut short their lives.
The frigates are back.
The hungry birds glide over the beaches, looking
for vulnerable hatchlings.
And the dangers aren't limited to the sky.
On the beach, a small but voracious predator lurks in its burrow.
If the red ghost crab spots any sign of weakness, it strikes.
It sees a straggler.
But struggles to penetrate the hatchling's leathery skin.
But it's not the only predator eyeing up the turtle.
To avoid becoming a snack himself, the crab retreats.
The little turtle grabs the chance to escape and makes a dash
for the water.
Of those that make it, they face decades of danger, as they swim
the ocean's currents before reaching maturity.
Only one in every 1,000 will make it.
Those lucky few that survive will eventually return to the bay
on the east of Gorgona to lay eggs of their own.
By the end of October, the adult whales are getting thin.
They've been living off their fat reserves for five months or more,
since they left Antarctica.
Now a 6-12 week return journey lies ahead.
They need food, soon, and lots of it.
The time's coming for them to migrate back south
for the summertime feast of krill.
Females that have successfully mated are the first to depart,
followed by mothers and their calves.
With no-one left to mate with, the males follow on.
The young male and his mother are among the last to leave.
They wait well into November.
It's taken him longer to bulk up
in preparation for the frigid waters of Antarctica.
Finally, he's ready.
He's now nearly 26ft long, well insulated with blubber,
and his swimming is strong.
He'll be weaned over the next few months, once he is adept at feeding
on plankton and small fish.
By his first birthday, he'll likely be on his own.
But he still has a lot to learn.
He stays close to his mother,
copying her every move,
as their epic journey gets under way.
He'll swim the ocean for at least five years
before he's ready to breed.
Then he'll return to Gorgona and join the chase.
A mighty giant, ensuring the future of Colombia's humpback whales.
Subtitles by Red Bee Media