[Tribal music, Singing]
[Background flute] In Africa, there lives an 
extraordinary tree.
She is the queen of the riverbank.
A monarch whose story stretches back millions 
of years.
[Flute background music]
In tribal cultures, her curious ways have fueled 
myth and legend.
They set her apart from other trees.
[Background flute music]
She is a sycamore fig. Queen of Africa's trees.
[Flute crescendo]
She appears never to flower, yet mysteriously 
she fruits several times a year.
She seems to have no regard for seasons, and 
drops her leaves when she pleases.
[flute background music]
Strangest of all is the relationship upon which 
she completely depends.
[flute background music]
The two partners couldn't be more different.  One 
can withstand a river in flood.
The other can drown in a dew drop.
[background cheerful chimes]
One lives for centuries. The other only hours.
They differ in size a billion times over.
At about a millimetre long, the fig wasp is so small 
that it could fly through the eye of the needle.
But no fig tree could exist without it.
[upbeat background drums] Sycamore figs are 
found throughout tropical Africa.
In southern Kenya, they thrive along river banks.
[flute background music]
This is the story of one of those trees.
[flute background music]
Our African queen is a mature sycamore fig.
She started life as a seed 100 years ago.
[flute background music] [animal sounds]
She provides for many animals.
[birds chirping]
To some, she is a hunting ground. To others, she 
is home.
[birds chirping]
She feeds a greater variety than any tree in 
Africa.
[birds chirping]
All rely on her tiny fig wasp partner that only a 
few even notice.
[birds chirping]
Every few months, the queen produces up to a 
ton of fruit.
To reproduce, she must transfer pollen to make 
seeds, and then disperse them inside figs.
The last crop fell only days ago. But up above, 
she is starting again.
Over the next two weeks, the tiny buds swell to 
become young figs.
[background music]
Hidden inside each are the queen's tiny flowers.
At this stage, a fig is not a fruit, but a secret 
garden,
whose delicate perfume attracts a flock of fig 
wasps.
[background chimes]
Their arrival will trigger a sequence of events that 
will resonate out through the bush.
[background chimes]
The wasps are all females, laden with pollen and 
eggs.
They must enter the fig via the garden gate to 
pollinate the flowers and lay their eggs inside.
[flute background music]
A one way passage leads to the secret garden.
Which is lined with hundreds of microscopic 
white flowers.
[flute background music]
Some of these flowers will become seeds. 
Others will be a nursery for fig wasps.
The tree will surround each wasp egg with a 
capsule,
called a gall, which will nourish and protect it.
[flute background music]
the wasps will soon die. But inside each hanging 
garden, their offspring will live on.
The queen is now their surrogate mother, and will 
care for them, until they hatch in two months time.
[birds chirping]
The fig wasps aren't the only ones to lay eggs in 
the tree.
For a pair of Grey hornbills is nesting.
[birds chirping]
This female's confinement will be temporary.
[birds chirping]
She seals herself in the hollow trunk, leaving only 
a slit through which her mate can feed her.
[birds chirping]
The swelling figs place a big demand on the 
queen.
To feed her wasps and grow seeds, she needs 
to make sugar with her leaves.
[birds chirping]
[crunching]
Animals that eat leaves are a major threat.
[crunching]
If the queen loses to many, she might have to 
abort her figs.
[birds chirping]
The only thing more damaging is a direct attack on 
the nursery.
[birds chirping, slurping]
To protect her leaves and young figs,
the queen pumps them up with a milky latex that 
is foul tasting and sticky.
[birds chirping]
Small offenders get stuck down.
And it's unpleasant enough to ensure that others 
don't stay too long to feed.
[birds chirping. leaves rustling]
Sycamore figs have been under attack for 
millions of years.
In their time, some insects have evolved 
strategies to overcome the defences.
[birds chirping]
A fig longhorn beetle bites through the veins to 
disrupt the flow of latex.
[birds chirping]
It starts with the main vein and works outwards.
[birds chirping]
Downstream of the damage, the flow is cut off, 
and the beetle can feed.
[birds chirping]
[upbeat background music] The fig Katydid cuts 
the flow of latex by cutting off the leaf.
[upbeat background music]
The pink mantis is a predator, but it's still very 
young,
and a Katydid this size is more monster than meal.
[upbeat background music]
The mantis can't fly. So to get off the leaf, it has 
to get past the green giant.
[intense background music]
[birds chirping, upbeat background music]
Beneath the tree, the fermenting juice in the last 
drop of figs attracts vinegar flies.
[upbeat background music]
An ideal size, the mantis still wants to snatch a 
bite to eat.
[intense background music]
[birds chirping, crunching]
The male hornbill is working hard.
For he now has three extra mouths to feed.
[birds chirping]
For hornbills, nesting is always a risk.
To try and plan her family for when most food is 
available, the female had to lay before the rains.
This year their late. And everyday that they delay
it will make finding food a little harder, and the 
chicks a little weaker.
[birds chirping]
To try and protect the wasp nursery from 
parasites, after the females entered,
the queen closed the gate, and flooded the 
garden with an antiseptic liquid.
It doesn't work against nematode worms, which 
use the female wasp as a trojan horse.
And stowed away in her body to get into the fig.
Inside they burst out and are now breeding to be 
ready to infect the next generation of fig wasps.
[intense drums]
Outside, the nursery is under attack from 
parasitic wasps.
They can't get in by the gate, so they drill through 
with a long ovipositor.
An egg laying device that works like a 
hypodermic.
[intense music]
Forced deep inside, it will deposit an egg on the 
developing fig wasp.
The grub that hatches will kill the wasp and take 
over it's gall.
[birds chirping]
The driller seems to have evolved the perfect 
strategy.
But, over time, even parasites can be exploited.
A smaller banded wasp has an ovipositor just as 
long, but more flexible.
[birds chirping]
The little wasps fight for access.
And, when the driller pulls out, the winner goes 
straight for it's hole.
[birds chirping]
It will use the same shaft to lay it's egg on the 
driller's.
For these smaller wasps are parasites of 
parasites.
[birds chirping]
In the queen's battle to protect her fig wasps, her 
allies are ants.
They will kill any parasites they capture.
[birds chirping]
Anything they can't subdue, they bite and sting to 
drive away.
[birds chirping]
The ants appear to be protecting the figs. And, in 
a sense, they are, for all are attacked.
[birds chirping]
All, that is, except one.
[birds chirping] [soft background music]
These tiny bug eggs should be the ideal snack for 
an ant.
But instead, the ants look after them.
[soft background music]
As they hatch, the ants gather up the babies.
They are nymphs of a bug called Hilda, which are 
herded up to graze as if they were sheep.
[soft background music]
Almost every fig now becomes a paddock.
[soft background music]
The ants are so attentive because a nymph
has hollow piercing mouth parts that enable it to 
tap into the fig's sap.
[soft background music]
The sweet liquid is under pressure, so it passes 
rapidly through the nymph.
[soft background music]
When it comes out, it still contains plenty of sugar.
So, in return for being nursemaids and 
bodyguards,
the ants receive a supply of sweet honeydew.
[birds chirping] [bee buzzing]
The wounds made by the nymphs and parasites
are healed with latex that dries to form a natural 
rubber.
[birds chirping]
The bee doesn't eat it, but collects it to take back 
to seal holes in it's own nest.
[birds chirping]
[bee buzzing]
[birds chirping]
It's been two weeks since the hornbill chicks 
hatched, and still it hasn't rained.
[birds chirping] [pecking]
Now the female must break out to help feed her 
family.
[birds chirping] 
As soon as she leaves, the eldest chick 
instinctively starts to plaster up the hole again
using droppings and debris from the nest.
It will be a while before it is ready to leave.
[birds chirping]
[thunder storm]
[tribal singing]
[soft music with rain]
[soft music with rain and tribal singing]
[soft music with tribal singing] [birds chirping]
The rains arouse some that have been sleeping 
for months.
[birds chirping]
They will bring the expected flush of insects.
But they have come too late for the youngest 
chick.
[birds chirping]
When their mother left, the largest chick 
dominated the food supply.
[birds chirping]
Chicks differed in size
because the eggs were laid a few days apart 
and hatched at different times.
[birds chirping]
There is a distinct pecking order.
So in lean times, the chick with the best chance 
of survival
gets to feed first and takes most of the food.
Even now, with both parents providing, the 
smallest dare not feed until the larger is full.
[birds chirping]
Despite clear skies, beneath the tree it still 
appears to be raining.
[ukelele]
These are fig cicadas.
They emerge after rain and tap straight into the 
sap.
Like Hilda, they vent what they can't absorb.
But to avoid getting their wings sticky, they don't 
drip, but squirt.
[background music]
From the tree's point of view, this is a major 
assault.
[monkey screeches] [birds chirping]
In the fight against cicadas, the queen needs all 
the help she can get.
For the ants have changed their allegiance.
Each time a cicada pulls out, it leaves a drop of 
sweet drop of sap, which bribes the security.
The ants are too busy drinking to protect the tree.
[birds chirping]
The sap is the only thing the ants will defend. But 
if news of it gets back to the hive,
then the bees will be back in force.
[birds chirping]
At the peak of the invasion, the trunk runs with 
sap,
and branches and leaves are sticky with the 
sweet drizzle.
[birds chirping]
Monkeys are opportunists.
Cicadas are only around for a few days each 
year so they get their fix of sugar while they can.
[birds chirping]
To begin with, there is no competition. But it didn't 
take long for the news to spread.
[Bees buzzing]
Fortunately for the queen, the cicadas disappear 
as quickly as they came.
[running water]
For the past two months, she has been making 
sugar to grow seeds and wasps.
Inside the figs, the protective fluid is drained 
away.
The exposed galls are no bigger than pinheads.
[background music]
The female wasps cannot hatch yet. They must 
wait for a mate.
[background music]
Male fig wasps have powerful jaws and a single 
intention.
[peaceful music]
Upon hatching, they cut through to the captive 
females.
Not to let them out, but to let themselves in.
[peaceful music]
A male has no wings, and only tiny antennae and 
eyes.
But in one area, he is very well endowed.
[peaceful music]
His cleft chin helps guide him in.
[peaceful music]
He impregnates a female before she hatches. 
With an organ that is so long and flexible,
that some males can mate without even leaving 
their galls.
[peaceful music]
[birds chirping]
Inside the trunk, there has been a dramatic 
change in behaviour.
As if adolecence had set in over night.
At dawn, the eldest chick started breaking down 
the door. It's time for it to leave.
[birds chirping]
In the confined space, the chick hasn't even been 
able to stretch it's wings.
So, if it's to fly, it will need instinct to kick in before 
it hits the ground.
[birds chirping]
It is an adolescent triumph of instinct over 
experience.
But it'll be a few days yet before the last chick 
attempts it.
[birds chirping] [peaceful music]
The queen can produce up to 100,000 figs.
Inside each, the female fig wasps
have enlarged the holes the males made, and are 
now starting to emerge.
[peaceful music]
They look very different to their mates, as they 
have large eyes, antennae,
and wings. All will be essential for their mission.
[peaceful music]
[intense music] The parasites hatch too.
For they rely on the fig wasps to help them 
escape from the fig.
[intense music] 
The nematode worms are trying to snag a female 
wasp.
[intense music] 
They all burrow into her body and slowly eat her 
alive.
But they can't kill her too quickly, as she is the 
only way they can reach another fig.
[intense music] 
The male wasp's next job is to cut flowers.
[nature sounds]
The white anthers contain pollen, and must be 
chopped down for the females.
[peaceful music]
Their mission is to carry the queen's pollen to 
other trees. It is why she raised them.
Pollination of a queen is exclusively by 
appointment.
[peaceful music]
The fig wasp female scrapes out pollen,
and carefully packs it into special pockets on her 
breast.
[peaceful music]
It is extraordinary behaviour.
Which has evolved out of millions of years of 
mutual dependance between wasp and tree.
[peaceful music]
Meanwhile, the males have started to tunnel.
It will take them some hours. But before they die, 
they must release the females from the fig.
[birds chirping] [bee buzzing]
These bees are scouts, sent ahead of a swarm 
to search for a nest site.
But it is already occupied.
[bee buzzing]
The baby hornbill is in danger.
If a single scout gets back, then the swarm will 
descend on the tree.
[bee buzzing]
It can't let any get away.
[bees buzzing]
[peaceful music]
In thousands of figs all over the tree, the 
tunnellers are about to break out.
In the space of one hour in the late afternoon, 
millions of fig wasps will emerge.
[peaceful music]
This is the final act of the male's brief lives.
[peaceful music]
For them, a glimpse of evening sunshine won't 
signal freedom, but death.
After two months developing inside the fig,
their lives have been whittled down to an intense 
few hours.
[upbeat music]
Now they give their lives to set the females free.
[upbeat music]
The winged couriers will never feed.
They can't survive more than a few hours in the 
sun,
and the worms inside are already weakening 
them.
Their's will be a race against time.
[upbeat music]
[upbeat music]
[intense music]
They don't hang about for good reason.
[intense music]
Ants don't distinguish between parasite and 
pollinator.
But it's the price the queen pays for security.
The ants kept many parasites from laying. So, 
ultimately, more fig wasps survive.
[peaceful music]
The activity attracts other players.
[birds chirping]
In it's bid to reach the wasps, a tiny day gecko
doesn't notice a giant stick insect. It plays an 
important supporting role.
[nature sounds]
Fig wasps can't sting. And they are so 
nourishing,
that in order to capture them, the gecko risks 
going out on a limb.
[nature sounds]
It relies on quick reactions and good eyesight.
[nature sounds]
Sometimes, that is not enough.
[nature sounds]
As a last resort, to distract a predator, a gecko 
can jettison it's tail.
[nature sounds]
It's a remarkable ploy. And if the gecko can stay 
out of trouble, then it's tail will grow back.
[nature sounds]
All over the tree, the queen's tiny couriers are 
being intercepted.
[nature sounds]
A spider cannot eat them all at once, so it wraps 
them in silk, trapped as a living larder.
[nature sounds]
For each wasp that is captured, hundreds will fly 
free.
It will be the flight of their lives. This evening the 
tiny wasps will set out,
in search of a fig tree, and another secret 
garden.
[nature sounds]
[peaceful music]
Some will find trees nearby. But others will be 
picked up by the wind.
And can travel over 100 kilometres.
[upbeat music]
[birds chirping]
In the aftermath of the breakout, the queen is 
littered with casualties.
Many didn't make it, or gave their lives so that 
others did.
[nature sounds]
[bees buzzing]
[bees buzzing, birds chirping]
One scout got away. And although the parents 
tried,
they couldn't entice the chick from the nest. It 
simply wasn't ready.
[bees buzzing]
[nature sounds]
The queen's leaves have done their job. For the 
last two months, they've been making sugar.
But the wasps have flown. And her seeds are 
ready to be dispersed.
[nature sounds]
When the wasps left, the figs ripened rapidly to 
become soft and orange, and full of sugar.
It's as if each is shouting, eat me!
[wonderous music]
[nature sounds]
Over 100 different kinds of birds eat figs.
All will fly off with a cargo of seeds.
[birds chirping]
Some eat little else.
[birds chirping]
A green pigeon is a fig specialist that flies miles 
from it's nest in order to feed.
[birds chirping]
The birds have waited for the banquet. And they 
won't be frightened off.
[birds chirping]
Back at it's nest, the green pigeon feeds it's 
chicks on a milk of liquid figs.
[birds chirping]
In this way, the bounty of the tree is spread far 
and wide.
[birds chirping] [footsteps]
Some can smell the fruit from miles away.
[grunts] [chewing]
Others live close by. And, while the queen is 
fruiting, visit every day.
[birds chirping]
There is so much on offer that the monkeys can 
be choosy.
They discard figs that are full of parasites.
[nature sounds]
With tiger beetles below, the wasps will be lucky 
to get airborne.
[birds chirping] [munching]
some figs remain full of parasites.
[nature sounds]
Inside them, all are dying. For parasites need 
pollinator males to release them.
[sad music]
If the parasites have been too successful, they 
can hatch, but never leave.
[sad music]
In this way the parasite numbers are kept in 
check.
[sad music]
[nature sounds]
Across Africa, more animals eat figs than any 
other fruit.
[chewing]
Fig trees are so important, because they fruit 
outside the normal fruiting season.
If they produced figs only once a year, the short 
lived fig wasps would die out.
To maintain the population of pollinators, each tree 
needs to fruit at random several times a year.
And this benefits everyone.
[nature sounds] [peaceful music]
In the heat, fig juice ferments into alcohol.
And the smell attracts some thirsty clientele.
[peaceful music]
The butterflies are normally shy and elusive.
But drinking alcohol though a straw has a 
predictable effect.
[happy music]
The inebriated insects are lucky.
As they don't taste very good, and most can still 
manage to fly.
[nature sounds]
The queen's generosity extends beyond the tree.
For those she provides for in turn support others.
[splashing]
Wherever fish gather, a crocodile is never far 
behind.
[running water]
[running water, birds chirping]
[birds chirping, crashing trees] [running water]
The croc sets it's trap in fast water, where the 
fish can't see it's jaws.
It won't see the fish, but it will react to the 
slightest touch.
[running water]
As figs are the bait, the croc makes a lot of false 
strikes.
[running water]
But, as in any fishing, patience is essential.
[running water]
[nature sounds]
Figs are sometimes eaten by people.
But occasionally the tree has something 
sweeter to offer.
[bees buzzing]
Traditionally, fig wood is used to conjure fire, for 
it is soft and smoulders well.
[friction]
The wood in which the bees found sanctuary is 
now being used against them.
[nature sounds]
Dry elephant dung is the tinder.
[nature sounds]
[wood chopping]
To gather honey, the Masai exploit the bee's 
instinctive response to smoke.
[crackling, bees buzzing]
It's evolved to protect the colony in the event of 
forest fire.
[crackling, bees buzzing]
When the bees smell smoke, instead of defending 
the nest, they gorge on honey and then flee.
In the fire, it would be more important that they 
escaped,
so they could reestablish the colony elsewhere.
[bees buzzing]
Normally, even a single sting triggers an attack. 
But, with the smoke, there's no reaction.
[bees buzzing]
The fig's flowers had nothing to do with this 
honey.
The queen's exclusive relationship with her 
wasps
means that her flowers never saw the sun.
And never had a visit from the bee.
[nature sounds]
[splashing]
Living by water helps spread the seeds, as figs 
float downstream and sprout along the strand-line.
A tiny echo of the avenue they came from.
[nature sounds]
It can be a one way ticket, unless the seeds can 
get help.
[nature sounds]
Migrating catfish carry some back upstream.
[nature sounds]
A lucky few will be planted and fertilised.
[nature sounds]
Strangely, no seedlings grow beneath the queen.
Despite the amount of fruit that falls.
[upbeat music]
Nothing germinates here. Not because of shade,
but because tiny seed bugs steal all the seeds.
[upbeat music]
They are specialists that eat only fig seeds.
[intense music]
To perpetuate the royal line, the queen needs help 
to get her seeds further afield.
[intense music] [bat screeches]
It doesn't arrive until after dark.
[bat screeches]
Fruit bats are the most important seed dispersers.
They're less agile than birds, so the queen makes access easier by dropping her leaves,
and hanging her figs clear of the branches.
[bat screeches]
Each bat needs to eat half it's weight in fig pulp each night.
[bat screeches]
They eat little else. And a diet of fig juice can result in an urge that requires immediate action.
[bat screeches, urinating]
Importantly for seed dispersal, a bat rarely eats in the fig tree,
but carries the fig a short distance away.
[bat screeches, munching]
He doesn't eat everything.
But sucks out the juice and discards the seeds.
So, beneath it's perch, sprout tiny fig gardens.
[peaceful music]
During the night, the female fig wasps have been travelling across Africa.
A few have found receptive figs
by homing in on the scent from the secret garden.
To enter, the female must squeeze through the gate.
[peaceful music]
Her wedge shaped head will help pry it open.
But it's so tight that her wings and antennae will be ripped from her.
And, in the final push, she literally busts a gut.
[peaceful music]
She must lay her eggs before the nematodes she is carrying burst out and kill her.
[peaceful music]
Her final challenge is to negotiate a spiral bowel,
that leads to the flowers. It might take an hour, and will need all her strength.
[peaceful music]
She will be alone in the garden, for the gate is closing. Others arrive too late.
[peaceful music]
[intense music] Inside, she is in trouble. The nematodes are breaking out.
[intense music]
She cannot last much longer, but must still lay her eggs and complete her mission.
[intense music]
The tiny wasp's final act is to repay her debt to the queen.
To unpack the precious pollen, and fertilise the flowers.
It is her gift. And the culmination of millions of years of co-evolution.
Between wasp and tree.
[celebratory music]
In perpetuating the relationship, she makes the ultimate sacrifice.
[peaceful music]
The queen's figs have provided for animals from ants to elephants.
In traveling, they will disperse her seeds.
[peaceful music]
Those seeds will germinate. And, somewhere in Africa,
where a bat perched, or an elephant came to drink,
there will grow a fig tree.
[upbeat music]
In a few years, it will sprout its first fig.
And the scent from that secret garden will touch a tiny wasp.
Which will turn upwind in search of the source.
Once again, the two will come together, and continue the extraordinary relationship,
that has provided for so many over millions of years.
[upbeat tribal music]
