Zambia's Luangwa Valley; one
of Africa's great wild places.
Life here experiences two
seasons vastly different
The wet and the dry.
And the dry season here is
one of the toughest imaginable
Almost seven months
with barely any rain
and rising temperatures.
Animals have to cope
with vanishing waterholes
and blistering heat.
This year is harsher than ever.
Global weather changes are
disrupting seasons everywhere.
Creatures large and small
clash in competition
for food and space.
Each day it gets
harder to survive,
but there are winners too.
The dry season provides a bounty
for those ready to exploit it.
25.000 hippos
call the Luangwa River home.
The largest population of hippos
anywhere in the world.
Groups, known as pods,
spread out along the river.
It's still deep enough for
them to comfortably submerge
and for now there's
plenty of space
to stay out of each other's way.
They constantly communicate.
Honking calls set off a
string of conversation,
called a chorus chain,
that travels all the
way along the river.
It's a way of amicably
letting other hippos know
who's who and where
pod boundaries lie.
A dominant male,
known as a beach master.
He's over 20-years-old
and controls a territory along
100 metres of this river.
His pod is made up of about 30
hippos, mostly females and young
and a few younger males
who he tolerates
as long as they're
no competition.
The youngest member of
the pod is a month-old calf.
She weighed nearly
45 kilos at birth
and on her diet of rich milk
she's growing fast.
But she's been born
at a tough time of year.
The valley is drying, her
river sanctuary shrinking.
It's mid-July.
It hasn't rained for two months.
The dry season has set in, but
it's yet to take its iron grip.
Over 700kms long and 100kms
wide, the Luangwa Valley
in Zambia is the tail end of
Africa's Great Rift Valley.
What makes it so special
is its patchwork of habitats.
Fertile grasslands are
flanked by shady woodlands
and dotted with lush lagoons.
It's an intricate network
of neighbourhoods,
providing homes for an
incredible variety of life.
At the heart of it all
is the Luangwa River,
one of the largest undammed
rivers in all of Africa.
It's a lifeline in the valley.
At this time of year,
the river is already half
its wet season size.
In a drying landscape it draws
animals from miles around.
Hundreds of species depend
on it for their survival.
Every dry season here is harsh.
It can be seven months
from May to November
with practically no rain
and soaring temperatures.
But this year the drought is
even more extreme than usual,
it's an El Nino year.
This global weather phenomenon
is triggered by changes
in warm water currents
in the Pacific Ocean.
It's far-reaching effects
span the planet,
and in Africa they can
intensify dry conditions.
The Luangwa River
meanders dramatically.
As it snakes through the
valley, soft sand is eroded
from the outer edge of a bank
and deposited on the inside.
Over time, these big bends
get cut off leaving oxbow lakes,
an echo of the
river's old course.
These lagoons are oases of
life and one of the reasons
the Luangwa Valley has such
an abundance of wildlife.
Some lagoons have
already dried up,
but this one is big,
nearly a kilometre long.
And there's still
plenty of water here.
Nile Cabbage grows all
over Africa's wetlands,
it's one of the most prolific
water plants in the world.
It floats on the surface,
its roots dangling in
the depths below.
It's a haven for
aquatic insects.
Larvae live among the submerged
roots and adult flea beetles
emerge in their thousands to
feed on the succulent leaves.
They in turn feed
hundreds of birds.
Jacanas have proportionally
the longest toes
of any bird in the world.
Nearly 20cm tip-to-tip,
front to back,
two-thirds of its body length.
They spread the bird's weight
as it tiptoes across the carpet
of vegetation without sinking.
Jacanas cannot delve deep
with their short beaks,
but they've learnt
to take advantage
of another lagoon resident.
The hippo is a
mobile feeding station,
vegetation lifted out of the
water give Jacanas access
to invertebrates hidden
in the root system
they otherwise couldn't reach.
And the hippo doesn't seem
to mind having hitchhikers.
This hippo is an old bull.
He's living a quiet life away
from the noise and commotion of
the main pods in the river, but
his lagoon won't last forever.
It's the end of July and
midday temperatures
are beginning to
creep above 25 degrees C.
More water evaporates everyday.
Now it's still deep
enough to submerge in
but the hippo will eventually
be forced to move.
Many of the valley's plains
are old, silted up lagoons
formed when the course
of the river has changed.
They're a testament to
the dynamic landscape.
The soil here is fertile;
washed down from volcanic hills
in the north, and nutritious
grass feeds hundreds of mouths.
Puku and impala have
small mouths and flexible lips
that are perfectly suited
to nibbling short grass.
But they don't have
the plains to themselves.
Grass makes up
half a baboon's diet,
but they feed very
differently from antelope.
They use dexterous fingers to
pick stems and pull up rhizomes.
Baboons and antelopes
compete for resources,
but the extra eyes and ears
make sharing worthwhile.
So many grazers attract
hungry predators.
But baboons have
excellent eyesight
and the ability to get a good
vantage point up a tree,
and antelope have acute hearing
and a strong sense of smell.
Between them they've got
the bases covered.
All benefit from
each other's alarm calls.
A lion on patrol has
no hope of an ambush
once the bush telegraph begins.
(Monkeys calling)
Even Africa's giants make use
of the fertile plains.
The tip of an elephant's trunk
is as sensitive as
a human finger.
Picking grass a blade at
a time is a slow way of
collecting the 130 kilos of food
they'll need to eat in a day.
But in the dry season
every little helps.
This calf is only two-years-old
but already he's walked
hundreds of kilometres.
An elephant herd must keep
moving, if they stay in
one place for too long they'll
annihilate their food supply.
The valley's woodlands are made
up of over 300 species of trees.
All with their own strategies
to survive the
crippling dry season.
Groves of Ebony Trees are
never far from the river;
their long roots tapping
into the groundwater.
The small surface area of
an Acacia Tree's tiny leaflets
helps minimize moisture loss
so they can grow
further from water.
But the most striking adaption
is found in a Mopane forest.
Every year it transforms
into an autumnal wonderland.
It's the beginning of August,
still early in the dry season.
But this woodland is several
kilometres from the river,
water is scarce.
Each Mopane Tree cuts off
the supply of moisture
and nutrients to its leaves.
Without the green pigment,
chlorophyll, leaves turn golden
and drop just like a
Northern Hemisphere fall.
The carpet of fallen leaves
creates a whole new habitat
on the forest floor.
Patterns in the sand
give their creator
the sweet, common
name of doodle bug.
But there's nothing
cute about them.
Less than half the size of your
little fingernail these insects
are the larval form
of a lacewing
and they are
voracious predators.
Huge pincer-like jaws
are vicious weapons
perfect for grabbing prey.
Their hunting prowess
has given rise
to their other
common name: antlions.
Each of these miniature
killers digs a tiny pit
about five centimetres deep.
It's carefully constructed
so the sides are at
a critical angle.
They'll collapse at the
slightest disturbance.
All he needs to do now is wait.
Ants are found in every habitat
in the world, except the poles.
And here in the tropics
can make-up, by weight,
as much as 25%
of all animal life.
There are plenty of them
and they're ideal prey.
This ant's making a heroic bid
for freedom.
But it's not easy to escape
an antlion's cunning.
Flicking sand
destabilizes the pit wall.
Injecting venom
paralyzes its prey
and enzymes digest the
ant from the inside out.
The antlion sucks its meal dry
as though drinking
juice through a straw.
And when it's done, it throws
the empty carton away.
But one man's trash is
another man's treasure.
White-browed Sparrow-weavers
hoover up anything
they can find in the leaf
litter; from insects to seeds.
They forage together in flocks
but at this time of year
food is harder to find
and they're getting
increasingly intolerant
of their neighbours.
Squabbles are short-lived.
These gregarious birds are
a model of community living.
In fact, they have one of the
most unusual social systems
in the bird world.
When it's time to breed
in a few months,
an alpha pair will be the only
birds in the group to lay eggs.
The rest of the flock
will help to rear the brood.
It's a bit like
a tiny wolf pack.
Each sparrow-weaver has its
own nest for roosting in
but the whole gang
helps build them all.
Nests may look messy but they're
in a constant state of repair,
a home improvement project
that is never quite finished.
All the nests are on
the same side of a tree,
a carefully selected position so
they get the right amount of
morning sun and are sufficiently
sheltered from the wind.
A double entrance
is a security feature,
in an emergency, you can
always nip out the back door.
It's now the end of August.
Four months of unrelenting dry.
In the river, it's getting
harder for the hippo pod
to find water deep
enough to submerge.
Their exposed backs are too
much for Oxpeckers to resist.
These little birds eat
anything they can glean
from a host mammal:
ticks, earwax, dead skin.
Having parasites removed
does the hippos a favour,
but Oxpeckers don't stop there.
They intentionally keep wounds
open, feeding on living flesh.
When the pecking gets too much
you have to master
the art of a tail flick.
These pesky birds don't seem
to mind taking a shower.
If all else fails,
a dunking dislodges even
the most stubborn hangers-on.
No matter, there's always
another hippo to hop onto.
And this time of year the dry
season has really taken hold.
The hippos' irritation
is worsened by
lowering water levels.
Less water means less room.
Neighbouring pods get
squashed closer together.
Beach masters start to get
twitchy about other males
cozying up to their harems.
Tensions are rising, and when
rival male gets in his way
the dominant male
loses his cool.
Mum must keep her baby close.
Three tonnes of angry hippo
could easily trample
a tiny calf.
It's only a small disagreement,
this time,
but it's a sure sign
of fireworks to come.
The river will only get lower
and the hippos will be squeezed
even more tightly together.
But for some, the shrinking
river brings opportunity.
Exposed banks are
the perfect nesting site
for White-fronted Bee-eaters.
Each colony is divided
into several clans,
extended families that
maintain close relationships.
Pairs mate for life
and share the task
of incubating their eggs.
A single Bee-eater can
eat 250 insects in a day.
And each brings food to
their partner on nest duty.
But in this society, cooperation
goes one step further.
Not all birds breed every year
and those who don't have a brood
to raise act as helpers
for those who do.
But there's always one who
doesn't play by the rules.
Stealing someone else's catch
is an easy way to
score a quick meal.
But it's a sure way
to ruffle feathers.
Encroaching on a rival clan's
territory can result in bouts
of beak-wrestling that
lasts for several minutes.
But a bonus of clan-living
is that there's always
someone around to
break up a fight.
It's the beginning of September,
rain is a distant memory,
and midday temperatures have
started to rise above 30C.
The lagoons are shrinking fast.
The old bull stubbornly stays
put, but time is running out.
He'll hang on as long as he can
but he'll be forced to move
when the water
vanishes completely.
Warthogs take advantage
of the fresh mud.
Wallowing helps dislodge
parasites but it is also one of
the most efficient ways to keep
cool in rising temperatures.
Warthogs are distant
relatives of the hippo
and like their cousins
have no sweat glands.
Covering their bare skin in mud
can lower their body temperature
by as much as two degrees.
This dwindling lagoon is one
of only a few in the valley
still to hold water.
It's a magnet for wildlife.
Impala must drink daily
in the dry season
when they get little
moisture from their food.
They come to the lagoon at
the hottest and safest part
of the day when most predators
are lying up in the shade.
It's still a
nerve-wracking time.
For the hefty buffalo,
which can weigh up to a tonne,
the trek across the mud to
water can be treacherous.
The mud is deep and
sticky enough to trap them.
But the desperate desire
to quench their thirst
drives them on.
A passel of catfish
is already trapped.
The hippo has unwittingly
cut off their escape.
The water is too shallow
to cover them completely;
they struggle to keep
their gills submerged.
Marabou storks have
spotted the movement.
Known as undertaker birds,
these bizarre-looking,
gangly storks are
usually scavengers.
But they are always
ready to exploit
any opportunity for a meal.
Their 30cm beaks aren't built
to deal with prey like this,
however.
Their clumsy eating habits have
attracted another opportunist.
A juvenile fish eagle.
This is a chance for him to
practise a tactic that will
stand him in good stead for
the future, stealing food.
Marabou storks are a metre
and a half tall and have the
largest wingspan of any
land bird in the world,
well over three metres.
They are formidable opponents.
But the fsh eagles are
armed with razor-sharp talons
and they're getting
good at using them.
There's no honour among thieves.
The eagle siblings each try to
steal the other's stolen meals.
Fish eagles are pirates
through and through.
Even a parent bird isn't
above pinching food
from its own offspring.
It's a tough world out
there and the sooner
that lesson is learnt,
the better.
Out on the plains, the dry
season is tightening its grip.
It's mid-September and
the ground is baked hard.
The elephant family is
on its way to the river.
Baby is still largely reliant
on his mother's milk;
he'll suckle for at least
another two years.
He needs to drink 12 litres
a day, and as it gets drier,
his mom will be
under huge pressure
to produce enough milk.
They've drunk at this stretch of
the river many times before.
But this time,
they're not alone.
On the other side of the
river is a second herd.
They've been foraging
far away on the escarpment
but there's nothing
left there to drink.
In the wet season, the mighty
Luangwa runs wide and deep,
a barrier separating the
east bank from the west.
But now, there is only
ankle-deep water between them.
The two families
size each other up.
Elephant's trunks are
packed with millions of
olfactory sensors, and they
have five-times more
scent receptor genes
than humans.
In fact, they have the
best sense of smell
in the animal kingdom,
and can recognize
individuals by their odour.
The new elephants are
actually old friends.
They haven't seen
each other for months
but as the old adage says
'elephants never forget'.
Touching trunks
is like a handshake.
And resting your
trunk on another
is an elephant's
way of hugging.
Elephant friendships
can last a lifetime.
At the White-fronted
bee-eater colony,
newcomers are not so welcome.
Each year during the dry
season, carmine bee-eaters
travel hundreds of kilometres
from South Africa, The Congo
and Tanzania to gather in
the Luangwa Valley to breed.
These are the vanguard,
a few hundred birds.
But over the next month,
thousands will arrive.
The little white fronts are
outnumbered and outweighed;
but they're not taking
this invasion lying down.
It's imperative that they
defend their burrows
from these red devils.
At last, an uneasy truce
is reached.
The Carmines can stay, but they
must dig their own nest holes.
The sand is easy to excavate
if you've got the right tools.
Their curved beaks work like
pickaxes, and fused toes
and strong claws make their
feet perfect for digging.
Stiff tail feathers
brace against the cliff wall
as they dig, helping
them keep their balance.
They'll tunnel two metres
or more into the sand
to create a cool,
safe place to lay eggs.
But the Carmines will have
their work cut out for them;
gathering food at the hottest,
harshest time of year.
It's the end of September;
there's not been a drop of rain
for over five months
and temperatures peak
at 37C each day.
This year, El Nino conditions
in the Pacific have caused
a drought that is even
more fierce than usual.
Waterholes have vanished almost
a month earlier than last year.
At the last of the lagoons,
thick mud is all that remains.
Butterflies gather
to take in minerals
and suck the last of the
moisture from the ground.
But behind them other
winged-creatures arrive.
Vultures.
Their eyesight is so good
they can spot a carcass
from several kilometres away.
The sticky mud has
claimed a buffalo.
On the wing, vultures
look out for signs
that others have found a meal.
One or two landing to feed
sets off a chain-reaction and
dozens more arrive in minutes.
A large gaggle of vultures
can strip a carcass
bare within an hour.
Swallowing nearly
a kilo of meat each,
a fifth of their weight,
in a sitting.
Their stomach acid is so
corrosive it kills most
bacteria, making them immune
to toxins in decaying flesh.
The hippo's lush
lagoon home is gone.
There's nothing left
but a muddy death-trap.
If he stays he could suffer
the same fate as the buffalo.
He has no choice but to take
his chances at the river where
confrontation with aggressive,
dominant males is inevitable.
He'll have to fight or die.
The dry season is far from over.
It could be two months or more
before the valley
sees rain again.
The young elephant will struggle
to keep up with the herd as it
needs to travel further and
further to find enough food.
But new opportunities will
present themselves to some.
As animals congregate around
the last of the resources;
it's good times for predators.
There are always winners and
losers in the Luangwa Valley.
