01x02 - Episode 2

[bunniefuu]

In the baking heat
of the African savanna...

...as rivers dry up...

...all animals flock
to the water hole.

We've never fully understood

how a single water source can
support so many competing species...

...so we're doing something
ground-breaking.

Welcome to Tanzania and to
the Mwiba Wildlife Reserve

and to this unique
water hole behind us.

We are working with the reserve to
create the world's first water hole

with a built-in specialist
camera system.

This water hole has a half-submerged
filming hide

right in the middle, and it's rigged
with remote cameras

so we can see every angle of animal
behaviour like never before.

Last time, in the peak
of the dry season,

our cameras captured

over 70 species.

Look at that! Extraordinary animals.

This emerging ecosystem quickly saw

wildlife working together
in surprising ways.

They're relying on
each other's strengths

to identify the predators
in the area.

Now we're entering the hottest time
of year, when temperatures soar

to an unbearable 40 degrees.

Turning the water hole
into a lifeline

for the reserve's most vulnerable...

That's a severed trunk. It is
amazing that it's still surviving.

...and making this precious water
source a target

for a clan of notorious predators.

They must be just out here.

I can't see them.
It's completely black.

This is the story of life
and death at the water hole.

We built our water hole
in Mwiba Wildlife Reserve...

...south of the Serengeti,
500km from the east coast

of Africa in Tanzania.

This is a safe haven for Africa's
most iconic species.

The long, dry season is drawing
to a close, and we've returned

for two critical weeks
at the hottest time of year...

...when water is an even
more essential resource.

After five months
of crippling drought,

food is also in short supply.

The grasses have died off
and acacia trees are almost bare.

The water hole is more vital
than ever.

ELEPHANT TRUMPETS

We're back at the water hole.

We're back at base camp
at the hottest time of year.

Yes, the big question is, what
effect will this raging temperature

have on the wildlife here

now that all of the other water
sources in the environment

have dried up and only our
water hole remains?

The water hole is now the main
source of fresh water

for 15,000 hectares of the reserve.

There's very little shade,

so getting here can be exhausting
for wildlife -

but, when water is
in such short supply,

it's worth it.

And on the first day of filming,

the water hole draws in
a thirsty animal

that we haven't seen before.

WHOOPING

Spotted hyena are one of the most
successful predators

on the African savanna...

...and an exciting
new addition to our species list.

I love hyenas. Look at that!
Oh, look at that!

Now, we didn't see them
at all last time.

It's just happily drinking,
it's on its own.

We're looking at the footage to try
and understand

what this typically nocturnal animal

is doing here during the day.

It's full, right?
Yeah. It's just eaten.

It's eaten.

Look, it's got a great big
tubby belly full of meat, there.

Hyenas often get thirsty
after feasting on a carcass...

...and it looks like this individual
may have made a k*ll nearby

in the past 24 hours.

It's pretty comfortable, isn't it?

Out in the open,
it's very confident.

I think this is probably an animal

that's getting to know
this water hole,

knows the lie of the land.

They live in clans

and, often, you know,
pretty numerous

in terms of, you know, the numbers
that you're going to get there -

groups of 20, 25 not uncommon.

Of course, they have this
reputation as scavengers,

but they are hunters as well,
they're really skilled hunters.

And, actually, it's more likely
that a lion will scavenge off them

than they will scavenge off a lion.

They have such a bad reputation

and yet they're actually kind
of gorgeous

and definitely really intelligent.

Yeah, smart, incredibly complex
social system,

governed by the females,
amazing behaviours,

and an essential part of the
ecosystem, of course.

It's such a privilege to see one out
during the day,

isn't it, though,
cos it's so unusual?

And I guess that's the advantage
of having all these cameras.

But, for other animals, however
thirsty they might be,

the presence of this predator
is likely to make them nervous

about coming to the water hole.

Only time will tell if this hyena
is here to stay.

20 cameras are positioned
around the water hole.

Calling up the footage offers
a unique insight

in how the heat
is affecting the habitat.

This is going back to the last
time that we were here.

And if we cast forward...
It's already quite dry.

Wow. OK, that got drier!

So there's lots of dry vegetation
there, but the vegetation is there.

If you cut to the next one.

Right. It's really barren.

It's so much drier. It's like
desertification, basically.

It is. The grass, the ground floor,
has dried out.

It's been eaten.

In terms of what's
available for herbivores to graze

around the water hole,

there's absolutely nothing.

All that is left to eat

are a few remaining leaves
too high to reach...

...and roots from dead grass.

Animals have to travel further
or dig deeper

to find anything nutritious.

The shape of the water hole's
changing a bit, as well,

whilst all the animals
have been coming.

A little bit on the top corner,
there, where it's shallower.

Presumably, they're just wallowing,
taking some of the material away.

At this time of year,

wallowing is one of the main ways

animals cool down.

They are hungry and tired,
desperately seeking shelter.

And it's this that allows
predators to thrive.

So, it's not surprising that,
on our first night,

we add new carnivores to our
species list,

including servals.

They are small savanna cats,

but are one of the most successful
hunters in the cat family.

They can leap up to three metres in
the air to catch birds mid-flight,

and they're known to hunt
up to 16 times a day.

The elusive African wildcat rarely
drinks water,

but uses its acute hearing
to precisely locate prey

around water points.

Spotted genets have retractable
claws to hunt in the trees

and down on the ground.

Now the water hole has become
a regular feature in the landscape,

smaller predators have plenty
of hunting opportunities

as small prey like rats
and hares come for a drink.

A few hours later, we get further
proof that the water hole

is a magnet for animals
from far and wide.

Look - hippo! Hippo are one of the
most powerful animals in Africa,

with canine teeth that can measure
up to half a metre in length.

This was something I really wanted
to see in our water hole,

and it was always on the cards.

You would think that,
in the foreground,

that's a source of
great temptation...

Oh, look at that!
..for a lonely wandering hippo.

They do move quite large distances
away from water,

looking for new water, of course.

But this hippo isn't searching
for water.

He's looking to graze.

Hippos walk almost 10km at night,

eating up to 40 kilos of grass.

Oh! To think that we could have made
a home for a hippo.

Now, come on! I'd put that on my CV.

With so much of the shrubbery
dried out, life is tough

for many of the animals here...

...but insects thrive

in this stifling heat, with the
humidity helping them breed.

This means lots of new insects
are spotted buzzing

around the water hole.

And insects aren't the only
new visitors. Migratory birds,

that have often travelled
great distances,

are also dropping in, including...

...the steppe eagle, which breeds
in Central Asia

before travelling
up to 10,000km to Africa.

HONKING

And Egyptian geese,
that pair up for life.

Once one dies, the other mourns
in seclusion

and often refuses
to mate ever again.

HONKING

A lot of the birds
flocking to the water hole now

are not coming to drink or bathe.

They're searching for food.

This is yellow-billed stork.
You can see how it got its name.

I've got a soft spot
for yellow-billed stork.

Now, when it comes to what they eat,
they are pretty much opportunists.

These animals will eat a frog
if they find it,

they'll eat a small snake
and a lizard

if they find it, they'll eat
fish if they can find them.

And that's what they're
looking for here.

What they're doing is they're
putting their beak into the water

and they're holding it slightly open
so that, if anything swims in,

they can snap it tightly closed
pretty quickly and capture the fish.

Super views! Look at that. Amazing.

I just feel a little bit sorry
for them,

because we've only just made
the water hole

and, at this point, there aren't
going to be any fish in it.

When the rainy season arrives
and the landscape floods,

new waterways will open up for fish
to find their way to our water hole.

But this won't happen for at least
another few weeks -

though no-one has told
the storks that.

It's sad, really, isn't it?

It is said that sometimes
the eggs of fish

are carried on the feet
of water birds -

ducks and things like storks.

You never know.

These animals may have brought
the very fish that they might eat

at some stage in the future
on those, their feet.

Birds are now the most frequent
water hole visitors during the day.

It's a far cry from the middle
of the dry season two months ago

when daytimes were busy
with many more species.

I have been studying the data to see
how much things have changed.

So this here is a plot of all
the animals' -

and not just some animals,
but all the animals' -

arrival times at the water hole.

Now, we're comparing our data
from the dry season

and now the hottest time of year.

So, when we were here last time,
you were looking at two peaks -

the animals were mostly
coming during the day

and then again at night.

But now you're seeing
a complete shift.

Buffalo that would arrive at dusk

are now waiting until darkness
at 8pm

before coming for a drink.

Elephants who regularly visited
during the heat of the afternoon

are now mostly arriving around 9pm.

Zebra, which used to come
around 11am every day,

are now turning up more frequently

between the hours of 2 and 4am.

What you're seeing is the animals
are preferring the night,

and, so, suddenly night has become
the new rush hour.

But night can be a dangerous
time to drink.

Mwiba is home to some of Africa's
top nocturnal hunters,

like leopard, lion,

hyena and wild dog.

On the fifth night, the highest
number of predators yet

comes to the water hole.

HYENAS CALL AND BARK

The spotted hyena returns,
and it's not alone.

OK, there's a clan moving in.
Look at that - seven.

Six. Now there's seven
at the moment.

There's eight there now.

I wonder if it's because
they've basically just built up

the confidence to come in here

or whether they have moved
into the area.

That's unlikely cos
they have quite stable ranges

and denning sites.

They do go wild sometimes. They do.

And they've got a remarkable
vocabulary - all sorts of whoops

and whistles and barks and howls.

Spotted hyenas are known
as laughing hyenas

because they have a distinctive call
that sounds like human laughter.

They can make more than ten vocal
sounds, but these can be modulated

to create even more meanings -

and they can hear each other's calls
from up to 5km away.

But, clearly, if they're moving
through the bush at night

and they're moving through
thick bush,

it doesn't matter
how good their nocturnal vision is.

They're relying on their sense
of smell

and, to communicate
with one another,

those calls that we hear
so frequently.

THEY CALL

They're not considered favourably,
are they, really? No, they're not.

They're looked down upon by many
African cultures and, certainly,

you know, Western cultures as well.

I think, because of their scavenging
nature, their nocturnal habits,

we're always fearful of things
that come out at night -

they're difficult
for us to see and understand.

Hyenas are highly territorial.

Now that they've discovered
the water hole,

their mere presence
is a threat to other animals

relying on this crucial resource.

THEY CALL

To help understand
the hyena's impact

on our emerging water hole
ecosystem,

I talk to Dr Meredith Palmer.

She's been studying Africa's
carnivores for more than a decade.

Meredith, we've got a number
of hyenas here.

The most we've seen at the water
hole is eight -

and, at the moment, it's dry.

Lots of herbivores are coming
to drink and then hanging around.

That must be ideal, therefore,
for the hyenas. Yeah.

So, having prey in high abundance
in a landscape

tends to favour hyenas.

Hyenas are apex predators
in this system,

exerting a lot of top down control
on what's going on.

Spotted hyena are the most abundant
large carnivore in Africa,

with an estimated population
of 47,000.

A lot of their success

comes from their complex
and highly adaptable social groups.

Clans consist of many non-related,
low-ranking individuals

led by an alpha female.

Working under her leadership,

they seek out areas
where prey congregate...

...like our water hole.

They know these animals
are going to be here.

The water hole is very good

because having a
high abundance of prey

allows their clans to grow
to very, very large sizes -

and if your clan is 40 or 50
individuals,

it's always going to win against
another species.

Dr Palmer's research suggests

that it's likely there could be even
more hyenas nearby

and, once hyenas are established,

the water hole becomes
a dangerous place to be.

Which could be why, following the
hyena clan visit,

clays and nights are a lot quieter.

To find out where all these hyenas
are coming from,

cameraman Bob Poole's
been searching the area.

He spotted a hyena den
with three young cubs

just 2km from our water hole.

There they are, look.

One, two, three.

And that's about the maximum
litter size

for one female, isn't it?

25% don't get through
the first month,

and they're born with incisors
and really sharp teeth

and their eyes open -

and as soon as they're born,
they're fighting one another.

But by the time they get to
this stage, it's all sorted -

they already know who's top hyena.

Bob and I take a remote camera
to see if we can get a closer look

at these cubs without
disturbing them.

It's the same as those that we're
using at the water hole.

We can remote control it
from the vehicle here.

We can pan and tilt and focus
and expose,

and we'll get a view of it here.

Bob here is a bit underexposed
at the moment.

But the purpose of this, of course,

is to allow us to learn a little bit
more about these young hyenas

close to their den.

Yeah, the cubs are still there.

They haven't minded us...

...being this close.

You can see here how curious
these cubs are.

We're only about, I don't know,
six, seven metres away

from the entrance to the den.

It's in their nature -
they're opportunistic animals.

So they're always on the lookout
for new things.

ENGINE STARTS

We deploy our camera
and move back about 30 metres.

These are likely to be all of them.

I think the same litter.
They're mobile pretty quickly,

and then they need to get
on their feet and get moving.

So the female hyena
has the most fat in her milk

for any terrestrial mammal.

By eight months, they're showing
hunting behaviour,

and, within a year, they're out
hunting with the adults.

The arrival of an adult female
lets us spot something remarkable.

There it is - there, look.

A newborn hyena cub.

It's much smaller.

It's just gone down?

That was much blacker
and much smaller.

Yeah, yeah.

But when the female heads
underground, it doesn't take long

for the older hyena cubs to start
investigating our camera.

One of the cubs is now just walking
down the cable line,

having a good sniff.

Oh, hold on.

This is the cable being pulled
by the other one.

There it is - look, look.

It's got the cable.

BARKING

I knew that this would happen.

It's gone.

For some reason, it's stopped
recording and gone back to this.

There's just no input.

Oh, they've pulled the cable out.

I don't believe it!

They have.

They've pulled it out of the back
of the camera.

That's a shame, because they'd just
plucked up the courage

to come right up to the camera,

so the camera did give us
the opportunity

to find out a bit more about them.

I think, from our point of view,
what's going to be interesting is,

you know, will these be the hyenas
of the future

that might visit our water hole?

After a few months, they will go out
with those adults,

and there's every chance that
they'll turn up down there.

Choosing a den so near
to our water hole

and therefore close to prey

is a key survival strategy

that will help this clan grow
strong in numbers...

...but the sight and the sound of
these powerful predators

will keep many other animals that
rely on this area for water away.

However, large animals
like this male elephant

are too big for a hyena
to take down.

And now that water is scarcer
than ever,

the water hole has become a lifeline
for one extraordinary individual.

We've seen him for over four
years now.

Mwiba guide Nuhu Mhapa
helps me to identify him.

It's amazing that he's still
surviving with such a trunk

that has been cut by a snare,
set by the poachers,

intending to catch some of the
wildebeest or zebras and so forth,

but, as the elephant moves
across the bushes,

grabbing these grasses,

then it just kept cutting the trunk,
so, it's painful,

but he has been with that kind
of wound for quite some time now.

Those trunks are so important.
They have multiple uses -

they are a hand when they eat,
they do help the elephants drink,

obviously, they suck it into
their trunks,

and then they
put that into their mouths.

But also they use it to signal
to other elephants.

Life is challenging for this
individual. Using their trunks,

elephants are capable of lifting
over 300kg,

something he will never
be able to do.

HE RUMBLES

Thankfully, he can drink.

But at this time of year, many
natural water sources have dried up

and are harder for him to reach.

Water deep enough to wade
into will help him to survive.

It must be also really sad
when you see this happen.

It is, it is.

And especially when you consider
that these animals,

they are long-living animals,

and you start to imagine
how hard it is for him,

just from this young age
all the way to 16 years old.

So it's tough.
It's very sad for us

because we humans have caused
these kind of problems.

So he's been affected very much.

So we've seen the effect
that the predators are having here

at the water hole,
but there is another species

that seems to be bullying just about
everything that comes for a drink.

It wants the resource
entirely to itself,

and our cameras can throw
some light on the matter.

QUACKING

Egyptian geese are aggressively
territorial at this time of year

as breeding begins,
and they've started fighting

over the water hole.

A mating pair
violently protect this patch

from other geese.

And it seems they're also
a surprisingly intimidating presence

to much bigger species.

THEY HONK

Not the quiet drink this giraffe
was hoping for.

Even predatory birds, like the
huge martial eagle,

are disturbed
by this boisterous couple.

THEY HONK

Whilst domineering geese are
unexpected,

it means our species list
has stopped growing at number 82,

as animals seem to be scared away
by hyena at night

or put off by geese during the day.

HYENAS CALL AND BARK

Over the next few nights,
hyena visits increase.

HYENA HOWLS

HYENA CALLS

And they're gaining confidence.

One night, a hyena appears
with evidence that it's been hunting

very close to the water hole.

It takes some scrutiny to determine
what this individual's doing.

It approaches the water hole, there,

carrying the limb of something that
it's either k*lled or scavenged.

Leg of wildebeest
it's got in its mouth there.

And rather than stop on the side,
put it down and have a sip,

it wades into the water
with that limb.

Now, some animals will wash
their food,

but it's not washing the food,
I don't think.

They will stash their food, hyenas.

They will cache their food.

You can see it's got a pretty much
full belly.

It's probably eaten as much
as it possibly can at this point.

It simply wades in
and then it comes back out.

Maybe it was thinking about caching
it in the water

and it had a change of heart
and went and hid it in the grass.

Sometimes, animals do
the strangest of things.

Now think about your own behaviour.

Sometimes, you do things
which are out of kilter

with not only human behaviour,
but your own.

Perhaps this hyena's
just got a leg quirk.

And that's the realjoy
of having cameras set up like this -

we get to see things like this

that, in a lifetime of personal
observation,

you're highly
unlikely ever to get to watch.

HYENAS CALL AND BARK

With our camp only 800 metres
from the water hole,

we're having more encounters
with the hyenas

than we bargained for.

The crew even spot one looking
for food right in front of them.

And they're brave enough
to visit our tents,

howling through the night.

HYENAS CALL AND HOWL

One of the great joys of sleeping
in a tent

in sort of the African night

is not sleeping through
the African night

because there's such a cacophony of
noises out there -

and you're laying there, thinking,
"What's that? What's that?"

but you don't have to wonder
about the hyenas,

and there have been a
lot of hyenas in the camp.

In fact, when I got up yesterday,
there was a trail of footprints

right down to the opening
of my tent, and I love that.

I love the fact that you're sleeping
that far away from a large predator.

You never get that feeling
in the UK.

HYENA HOWLS

They are sticking to that whooping
sound that they make as opposed to,

well, more of the laughing sound,
but it is...

...it does sound like it's everywhere

and it's been going on
for a few hours

and we are really close
to the water hole.

They're even using the same trails
as us to get in and out of the camp.

But not all animals are threatened
by the hyenas

and, over the next few nights, we
add more new species to our list.

Bats dive-bombing the water hole

can eat up to 3,000 insects a night.

CROAKING

Toads absorb water directly
through their skin

so they don't need to drink.

CROAKING

This morning, a Mwiba guide

has told Bob a carcass
has been found close by.

The carcass is just 600
metres from the water hole,

so, Bob is keen to find out

what might have been hunting
in the area.

When the Mwiba guide found
the carcass last night,

he placed a camera trap on it.

Bob wants to confirm if this
is a hyena k*ll.

HYENAS CALL AND BARK

With spotted hyena working together
to take down large prey,

it looks like they're now the
apex predator dominating the area.

Earlier in the dry season,

we discovered a local lioness

was also hunting near the water hole
to feed her cubs.

But we haven't seen her or the cubs
since we've been back.

Could the hyena have
driven them away?

To find out, Bob is going to
check the camera traps

we placed around the lion den,

3km away.

HYENAS CALL AND BARK

HYENAS BARK

HYENAS CALL AND BARK

To discover if the lioness
and her cubs are still alive,

Bob has to extend his search.

He spots evidence of lions

over 16km from the water hole.

The lioness has successfully moved
her cubs away from the hyenas.

Lion territories can range in size
from 20 to 600 square kilometres,

and cubs are often relocated several
times a month to keep them safe.

But other animals can't move out
of the area so easily...

...and have no choice but to
risk their lives

coming to the hyena-dominated
water hole.

This vervet monkey mother
needs to drink every day

in order to keep producing
nutrient-rich milk for her young.

The baby clings on tightly
whilst on the move,

something they're
able to do from birth.

The rest of her troop
are nearby to keep watch.

Vervet monkeys raise high pitched
alarm calls if they spot danger.

They use a different call
for each predator

to signal different
escape strategies.

With the coast clear,

she makes it to the water hole.

The baby gets all the fluids
it needs from its mother's milk,

so as long as she gets enough water,
the baby will survive the heat.

On day 12, it's 39 degrees,

our hottest day yet.

And a rather unexpected new species

turns up at the area
around the water hole.

COWS MOO

Ella, look at this.

Yeah, they're not supposed
to be here. Trespassers.

Right, so these cows are not
supposed to be in this area.

It's a protected area.

Around the outskirts of Mwiba,

there are many Maasai villages
that keep livestock.

Their cattle are banned
from entering the reserve

in order to stop overgrazing.

But there are no fences in Tanzania
between nature reserves

and human populations,

so enforcing this ban is difficult.

In this wild place where people
and animals live side by side,

there are no easy solutions,

and at the toughest times
of year, like now,

trespassing is likely to increase.

Where's the person that's looking
after these cows?

Or is there nobody
looking after them?

No, there should be someone
looking after them,

because, obviously,
they're potential prey

and they are currency, aren't they?

You know how valuable they are
to the local community,

so they don't let them ramble
and roam at will.

Look, there you are.
There's the human, there.

See, the thing is, he's going
to get fined. This is the thing.

He will get a heavy... A fine.

Yeah, he'll get a heavy fine
for being in this area,

and so he's taking a massive risk,
being here.

I guess I'm wondering why he's...

...why he's brought them in,
when there's such risk.

Perhaps this is his only choice.

It's either bring those animals
in here,

or they're going to die
of malnutrition... Yeah.

...and he's going to lose
his livelihood

and perhaps even the lives
of some of his family.

Presumably, he's taking
the risk of that fine

simply because there isn't
an alternative elsewhere.

Eventually, a Mwiba ranger escorts
this herd out of the reserve.

The presence of these cows

shows just how harsh the environment
can be at this time of year,

and why water is such an
important resource for all.

THUNDER RUMBLES

Finally,
after five months of drought,

three millimetres of unexpected
rain brings some relief.

THUNDER RUMBLES

It's not enough for grass to grow
or natural water holes to fill...

...but it does lead to a sudden
expl*si*n of life - insect life.

Look at this beauty. Huge beetle.

I notice that the tent has
become a bit of an insect trap,

particularly at night,
with the lights on.

They're drawn to those lights,

and they're typically more active
at that time.

It's cooler, it's more humid,
best time to be flying around,

particularly if you're a large
insect like this.

We might call it a longhorn beetle.

It's got these characteristic
long antennae here,

typically extraordinarily sensitive,

for finding members
of the opposite sex.

And given its size,
I should imagine that this creature

has been living as a grub,
perhaps inside some rotting wood,

for a number of years.
And, having emerged as an adult,

their job is to mate and then
disperse, lay eggs and die,

get eaten by something bigger,
perhaps even more interesting,

something that might happen in the
space of just a couple of weeks.

And on that account,
I'm going to put it outside

so it can do its business.

ELEPHANT TRUMPETS

Our water hole has become
a lifeline for many species,

from the smallest to the largest...

"including the elephant
with half a trunk."

He has returned to our water hole,

and this time he's with a herd.

Elephants are highly social,

and other members of the group
are keen to interact with him.

They use their trunks
to communicate,

smelling and touching
each other's mouths.

It's essentially
an elephant handshake.

Half trunk does his best
to return the gesture...

...making a vital social bond...

...and confirming him as
one of the family.

Over the past two weeks,

we've seen hyena numbers increase,

and their visits intensify,
both day and night,

but we still don't know exactly
how many there are in this clan.

We're excited to have spotted
hyena around our water hole,

but it would be great
to know how many there are.

The trouble is, counting them
can be really tricky.

Firstly, they're nocturnal,
of course,

which makes them difficult to see,

and then they move around
in fluid social groups.

So, if you count six here,

two of them could be from the four
that you later count over here.

We clearly need a different method.

We need it to get dark and
we need to bring the hyenas to us.

Dr Meredith Palmer has
carried out similar experiments

all over the Serengeti...

...and can help us shed light

on how big our water hole
hyena clan might be.

So, Meredith, how are we going
to try and count these animals?

So, we're going to do
a call up tonight.

We're going to play some sounds
that might intrigue the hyenas

and bring them out of the bush

so that we can get a good
look at them and count them.

We're going to start by doing the
sounds of prey animal in distress,

playing the sounds of a warthog
that's having a very bad day.

If you're a hungry hyena,
this might be the kinds of noises

you would come and investigate to
see if you could get a meal.

We'll then play some hyena
social noises.

So we'll play the long
whooping calls of the hyenas,

and the calls I have are calls
of hyenas that don't live here.

They're strange hyenas.
They're foreign hyenas.

And if this was your territory,
if you were a resident hyena here,

you would definitely want to
come investigate

whatever strangers
might be coming through.

OK, so now we're playing a warthog
having a very bad day.

In terms of sort of disturbing their
behaviour, the ethics of this,

you know, we are playing
an artificial call,

we're moving them around
the environment,

but presumably only for a brief
period of time

over a short distance?

This is very noninvasive.

This is a very minimal
kind of experiment

to study their behaviour
and their population.

OK, shall we give a go, then?
Let's do it.

Let's wind them up
with a bit of wounded warthog.

WARTHOG SQUEALS IN PAIN

Hyenas come together en masse
for two key events,

either for a feast or when they're
trying to defend their territory.

Tonight, our two different calls

are attempting to lure them in
for both.

If we are able to
bring up any hyenas,

we can see the different spots,
we can see the different scars,

and we'll be able to identify the
different individuals that come up.

OK, what about range?

How far away... from how far away
can we bring them in?

So, we're playing these calls
quite loud.

The hyenas should be able to
hear calls played at this decibel

for about 3km.

If they're within that radius,
they might come investigate.

It's pitch black.

So we can see is the infrared
camera feed on the monitor.

And within just four minutes,

the first hyena turns up.

WHISPERS: Didn't take them long to
arrive, did it? Came very quickly.

Yeah, they must have been
in the immediate vicinity,

which points to the fact that
they're using this water hole.

So they'll be occupying this area.

Their quick arrival
suggests they live nearby,

quite likely at the den
I visited with Bob.

Oh, there's two of them.
Oh, there's two.

HYENA BARKS

That's them...
There's one over here.

Geese aren't moving, are they?

They're absolutely frozen solid.

They must know those hyenas
are there.

They're moving...

There's another...

Around the back...
Oh, there's another one here.

There's three.
Three, at least. Yeah.

Hyenas are highly social animals,

and their clans have very
complex hierarchies.

When two hyenas meet,

the subordinate animal lifts its leg
to the dominant hyena

so it can examine its genitalia.

There's one close here, though.

That one must be just out here.

The dominant female usually
has her tail upright

and the subordinates keep
their tails and heads down.

HYENAS CALL AND BARK

We're hoping to work out
which hyena is the leader.

There's another. There's another.

Four. Four, yeah.

Five, six!

HYENAS BARK

They must be just out here.

I mean, I can't see them,
it's completely black here.

We're using infrared light.

Those hyenas can't be
any further than...

...I don't know, six, seven,
eight metres away, just out here.

They sound so close. Yeah.

HYENA BARKS

And more keep coming.

You can see them now. Look,
cos they're here, aren't they?

The whole crew. Yeah.

They're surrounding this...

HYENAS CALL AND BARK

It's amazing to think that
these fantastic animals

are just a few metres away
out there.

How many are there at the moment,
Meredith?

11. 11?!
Wait, there's one more coming in.

11? Are you serious?

That's the most we've had here,
then.

Yeah.

With such a large group
gathered on camera,

we can work out that these
two smaller hyenas

are the most dominant,

by the way the others
are behaving around them.

God, I wish I had infrared eyes,
I really do.

Once the calls stop,

this clan soon moves on.

That's the last one, look,
dashing off into the darkness.

Yeah, what about that?

Top work, Meredith.
That was really good.

It's a brilliant sighting.

With 11 hyenas coming to the
water hole in just 19 minutes,

Meredith's previous research
suggests that it's likely

there are other hyenas in the clan

who are out of range
or at another k*ll.

She estimates there could be
as many as 25 in total.

I've got to say,
what an extraordinary experience.

It was so enigmatic, knowing that
these large, powerful predators

were just a few metres away
in the darkness.

We could hear them.

We couldn't see them.

Sadly, we couldn't smell them.

But they were just within reach.

Amazing. Amazing.

This hyena clan has
taken over our water hole,

and I've been compiling the data
to look at the impact

of their ever increasing presence.

We've been studying the number of
hyena visits at the water hole,

and what's interesting is that these
visits have continued to increase.

We spotted 73 visits.

Hyena now come nearly every day,

but with water running desperately
low across the reserve,

new animals still risk visiting
this crucial lifeline.

We've had an additional 17 species,

including the hippo and the servaL

That means our total count
of animals

that have turned up
to the water hole

since we opened it
just a few months ago is 88.

Over the past two weeks,

we've seen life at the water hole
completely transform.

But everything
is about to change once again.

The rains are already here,
a month earlier

and a lot heavier than usual.

In the coming months,
more rain will fall on Mwiba

than in London in a year.

A deluge that will have a
huge impact on the water hole.

We're back during the
height of the rainy season,

when there is an expl*si*n of life.

One of nature's greatest spectacles,

the wildebeest migration, arrives,

bringing an influx of
new prey and predators.

It's just incredible to witness.

And our water hole ecosystem

enters an important new stage
of its evolution.

All of the animals that have been
coming here have been visitors,

but now we've got some residents.