Original subtitles

In Galapagos, this majestic tortoise is in a bit of discomfort.

He's got an itch he can't scratch.

The answer?

To partner up with a finch.

The finch pecks out all those irritating ticks and grubs.

The bird gets a meal,

the tortoise gets relief.

Everyone's a winner!

There are times in life

when all you need is a little help.

It could come from members of your own family,

or from some more unusual allies.

Across the natural world,

some extraordinary partnerships between animals

are being discovered.

Whether it's a lion and a lizard...

..or a raven and a wolverine...

..no matter where they are on the food chain,

many creatures have learned that life can be a bit easier

when you find a perfect partner.

Out in the wild, survival is paramount,

but even in this pristine wilderness,

just staying clean is a daily challenge.

One way is to enlist some help,

but that can depend on whether there's mutual benefit.

Across Africa, hippos are considered among the most dangerous of animals.

They can be unpredictable

and highly aggressive.

They certainly appear tough enough to look after themselves.

But their impressive hides are prone to irksome parasites.

Unable to pick up a stick and scratch their own back,

they've gone into partnership.

Meet the barbel,

a hippo's best friend.

These graceful goliaths are trailed by shoals of these loyal fish.

They even eat the droppings - what a bonus!

Once in a comfortable spot the barbels get to work,

nibbling away at all the hippo's unwanted guests.

It's a bit like a spa treatment,

complete with facial, full body exfoliation

and it seems to lull the hippos into a kind of trance.

Thanks to the food stuck to the hippos' teeth, the industrious fish

are able to feed on exotic vegetation from the land,

which would otherwise be out of their reach.

Timing and agility are essential here.

It's a peculiar pairing, but it seems to work.

The fish get a feast and the hippos submit quite happily,

perhaps making us see these aquatic curmudgeons in a different light.

Many creatures need help with their personal hygiene.

Even in the depths of the sea

are fish which could do with a bit of a once over,

but, at times, finding the right cleaner

can require a little more effort.

For these jacks,

their skin parasites are more than just annoying.

If not removed, they can reduce their growth.

This specialist cleaner fish, the wrasse, offers relief.

But the brightly coloured wrasse is recognised by many other fish,

all wanting the same service.

It leaves the jacks with a problem

as there just aren't enough cleaner wrasse go around.

So the jacks have to find a more precarious solution.

At first glance, it seems an almost suicidal option.

This is a silver tip shark and could easily eat a jack.

But these sharks have skin like sandpaper

and bumping into their flanks helps scrape off unwanted parasites.

Soon swarms of jacks pursue the sharks, all itching to have a go.

A dangerous game, but perhaps one that's tolerated.

Could all this bumping around also help to exfoliate shark's skin?

A case of you scratch my back and I'll scratch yours.

Eventually, though, the sharks have had enough

of being used as mobile loofahs and they're off.

For the jacks, they must be doubly relieved -

to be rid of their itches and to be alive.

On the African savanna, another animal is about to take a big risk.

He's very hungry and he knows where there is guaranteed food,

but catching it will mean getting up close and personal

to one of the fiercest predators around.

After a hearty meal of wildebeest,

the lions are doing their best to take a siesta.

But under the scorching hot sun,

they are surrounded by irritating and relentless flies.

Step up Mr Lizard,

perhaps the bravest cleaner in the world.

Lions do eat lizards, but having already had a much larger meal,

they are unlikely to need dessert.

Still, best to be cautious as lions can be notoriously short-tempered,

even if you're doing them a favour.

It takes a bit of courage and skill,

which not all the lizards possess.

Across the world, their lizard cousins

have struck up a similarly special relationship

with another type of lion.

The lava lizards of the Galapagos

rid their seal lion friends of flies,

which can be ticklish nuisance.

Here, the busy cleaners appear a lot less cautious and much more welcome.

Back on the savanna,

it seems that as long as the lizards let the sleeping lions lie,

they will be rewarded with a tasty snack.

How appreciative the lions actually are of their fly-swatting efforts,

well, who knows?

Some animal partnerships go much further than just cleaning.

When you need a bit of home help

or you're having a spot of bother with your neighbours,

it can be worth considering a lodger.

In the coral reefs is perhaps one of nature's oddest couples.

This lugubrious goby has been offered lodging from a shrimp.

The shrimp is the perfect homemaker,

always cleaning, digging extensions and carrying out home improvements.

Yet its chosen lodger seems rather lazy,

just hanging about and occasionally getting in the way.

Despite first impressions,

the goby is, in fact, crucial to this partnership

as the shrimp is almost entirely blind.

The goby, on the other hand, has excellent eyesight

and remains constantly alert.

So, when the shrimp is outside,

it continuously flicks one of its antennae over the goby

to make sure it's still there and the coast is clear.

The shrimp nips across to collect food from a little patch of algae

that it knows is close to home.

However, if the shrimp wanders too far there can be trouble.

That was an anemone it blundered into and it beats a swift retreat.

For a moment, it seems a little lost,

but the faithful goby finds it

and this devoted pair are soon reunited.

This predator spells danger for both creatures.

But the goby gives the signal

and both grateful landlord and lodger retreat safely indoors.

Happy with that - that's the rent sorted for another month!

Sharing a home can lead to living on top of each other,

but for some creatures, this can be a distinct advantage.

One such animal lives in the rainforests of Latin America.

The famously slow-moving sloth.

Thanks to its damp fur,

it is able to employ the help of a rarely celebrated organism - algae.

It helps the sloth blend in to its green surroundings,

providing it with a sort of living camouflage.

And the partnerships don't end there.

The nutritious algae attracts its own admirers -

insects like these moths, who like to eat it.

But the moths are welcome lodgers for the sloth

as they too bring their own rather surprising benefits.

Once a week, their sloth landlord sets off to the ground

at a pace a snail would consider reckless.

He does this for his weekly call of nature.

The female moths take this opportunity to jump off

and lay their eggs in the steaming dung.

Some hop back on to their furry friend,

bringing with them a lovely bit of sloth dung.

It's the perfect fertiliser for the growing algae,

helping to keep the sloth the right shade of green

and hidden from predators.

Perfect!

Some animals go to quite extreme depths in their quest

to find a secure place to lodge.

A pearl fish is looking for exactly that - a hidey hole.

This cumbersome oddball could be the answer.

A rather strange looking lump known as a sea cucumber.

It spends its days sucking sand in through one end of its body,

extracting anything nutritious from it

and passing what it doesn't want out the other end.

It is the ultimate beachcomber.

OK, it's revolting, but could this walking colon be a safe haven?

It seems it could and, strangely,

it prefers the 'back door' to the front.

Any port in a storm...!

But the pearl fish is, in fact, very clever.

Sea cucumbers are repulsive to most predators,

meaning the crafty lodger is safe inside.

In fact, it is such a comfortable pad that, after settling in,

it is happy to share its home with friends and family.

Now, time for a breath of fresh air!

Whether invited or not,

partnerships can involve all kinds of diverse creatures.

Some of these creatures pair up not with animals, but with plants.

In Madagascar, the baobab tree is regularly pollinated

by the giant hawk moth.

But the tree also plays host to another creature,

one which will kill a moth.

The mouse lemur,

one of the world's smallest primates.

He drinks the sweet nectar from the tree's flowers.

It's packed with sugary energy.

But he particularly enjoys a meal of moth.

It seems the lemur is doing the baobab no favours

by killing its moth pollinator but, without knowing it,

this mini assassin is actually performing the same role.

As he wrestles with the moth, his fur becomes dusted with pollen.

Later, as he moves from tree to tree,

this will spread across the forest, helping other baobabs to grow.

So, in this relationship, the baobab is surprisingly the ultimate winner.

On the other side of the world

is a partnership which has knock-on benefits

for the most unlikely of candidates.

This Sundarbans in southern Asia

are the largest tidal mangrove forests in the world.

And a tiger reserve.

Mangroves are the only trees that can exist in salty water.

They have roots which stick up like snorkels sucking in oxygen

as they can't get enough out of the thick mud.

But mangroves need more than this to thrive.

Luckily, they have found an ideal partner.

One which can only be seen at low tide.

Millions of crabs.

Leaf-eating crabs and fiddler crabs.

They make their homes here.

It's an ideal place for them

to create their labyrinth of underground tunnels.

The tunnels are vital for the mangroves.

At low tide they channel air through the mud.

Also, crabs help nourish the trees.

The fiddlers recycle the bacteria-rich mud,

releasing nutrients for the roots.

While, as their name suggests,

the leaf-eaters gather up and digest the mangroves' leaves,

producing their own natural fertiliser.

The crabs' burrows even help control the saltiness of the swamp.

When mangroves take up water, they leave the salt behind.

As the tide comes in, fresh seawater floods the crabs' burrows

and dilutes the salty remains.

Less toxic mud allows the mangroves to flourish.

Without their crab partners, the Sundarbans just couldn't survive

and without the Sundarbans,

the tigers here would also be in trouble.

Crabs helping to secure the future of a tiger?

You have to admire these sideways eco-warriors.

Protection is paramount in the endless battleground

that is the natural world.

It could be a crucial warning call in return for titbits...

BIRD CHEEPS

..but it always pays to have someone to watch your back.

Surprisingly, though, this protective friend

can sometimes be a creature you'd expect to be your archenemy.

Normally, this venomous tarantula would eat a small toad,

but here it is welcomed into the protection of its lair.

It's not a personal thing, it's purely business.

The toad offers a useful service.

Pest control.

The spider's egg sacs are infested with insects,

which the toad soon makes a meal of.

In return for getting rid of the ants,

the tarantula offers very effective security.

Screech owls enjoy a dinner of toad,

which would normally be easy pickings.

But the spider unleashes a barrage of barbed hairs.

Like tiny vicious arrows, they soon discourage the unwelcome intruder.

The coral reef, thriving metropolis of the ocean.

With such a rich and diverse habitat,

no wonder so many remarkable partnerships have evolved.

These small, defenceless clownfish

seem to have picked a tough place to live,

amongst the tentacles of a sea anemone.

The anemone is armed with paralysing stings -

stings that can kill a fish.

To avoid this fate,

the clownfish dance deftly among the stinging tentacles.

They produce a special mucus

which, ultimately, stops the stings from firing.

Very quickly, the clownfish are immune.

They've effectively found themselves a security partner

and turned the anemone into their very own fortress.

It's an ideal one for them to lay their eggs.

In return, the constant movement of the fish

helps oxygenate the sea anemone - a perfect reciprocal arrangement.

Keeping safe and secure

can be all about choosing the right kind of neighbour.

These burrowing owls

have chosen to move into a large estate in North America

known as 'Dog Town'.

It's a huge area of underground tunnels

built by a community of prairie dogs.

The owls have chosen this rather rough-looking area

as it has a well organised neighbourhood watch scheme.

The prairie dogs provide a free and very sophisticated security system.

Members of their community take it in turns to watch out for predators.

The lookout guard has different calls for different threats,

threats to both the dogs and the owls.

PRAIRIE DOG CHIRPS

PRAIRIE DOG CHIRPS

CHIRPING

The wise owl may be a myth,

but these earthbound head-turners are a savvy bunch.

At times, survival can depend on taking opportunities

when they come along.

Some creatures are better at exploiting them than others

and often it's a case of how sneaky you're prepared to be.

These capuchins live in one of Brazil's most extreme landscapes,

where food is hard to come by.

So they have had to have learn to be very resourceful.

They have spotted a yellow rat snake,

a creature which can be dangerous for young capuchins.

The capuchins all work together,

trying to make as much noise as possible to scare off the snake.

Then they realise the snake offers an opportunity.

It has found a Brazilian rodent called a punare -

a potential meal for both snakes and capuchins.

The punare has nowhere to hide.

Very soon, the silent hunting technique of the snake has paid off.

Then, one of the capuchins attempts something rather risky.

With hundreds of backwards-facing teeth,

the snake is not going to give up prey easily.

It was worth a go.

But the snake has created an opportunity

for the quick-witted capuchins.

There's more than one rodent up for grabs here.

The most experienced male takes the lead.

Got it!

With a little help from the snake,

the capuchins have cleverly scrounged themselves a meal.

Sneakily scrounging from other animals is a smart move

and some creatures have become expert at it.

Cowbirds have latched on to a much larger animal than themselves.

They do so because the movement the bison make

stir up hundreds of insects, which the birds eat.

A good roll in the dust throws up a decent meal,

but the tiny birds also know when to keep out of the way.

Just as well, as the males can get quite excited and aggressive.

Living close by and scrounging from these big beasts

helps guarantee the birds' survival.

When the bison migrate, the birds will follow.

These little birds even lay their eggs in other birds' nests,

so their chicks are unwittingly brought up by others.

They do this so they are not left behind when the bison move on.

You have got to hand it to them,

these birds are more than just a bit sneaky, they're ruthless.

In the icy forests of the Arctic, are two very cunning scroungers

that have, surprisingly, learned to work together.

RAVEN CALLS OUT

In this bitterly cold landscape, a raven calls out.

RAVEN CALLS OUT

It's found its dinner, but it needs another animal's help to enjoy it.

The wolverine.

The raven, a highly intelligent bird, directs the ravenous wolverine

to the moose carcass it's found.

The moose is frozen solid - too hard for the raven to break through.

The wolverine's powerful jaws

make short work of this frozen ready meal, exposing the softer middle.

The raven will have to wait until its partner has had its fill.

But it knows that patience will eventually pay off.

The wolverine drags a chunk of the carcass off into the forest.

But there are plenty of scraps left for the raven.

And its friends.

What the wolverine can't manage it will bury for a later date.

It's always useful to have extra food in the freezer!

In the struggle for survival,

cooperation with a completely different species

can be a way of gaining a crucial advantage,

but some animals have learned that working together

within their own family is the key to success.

Elephants live in large groups with strong social bonds.

This large herd in Kenya

is made up of several females and their offspring.

Amongst the herd is an inexperienced mother with a newborn calf.

She couldn't keep up with the herd,

but the grandmother of the calf has stayed behind to help.

Meanwhile, the rest of the herd reach the river.

The older calves are unceremoniously encouraged to take the plunge.

You could call it tough love.

In her effort to catch up with the others,

the new mother leads her baby across a slippery mud pan.

It's not the best route for a newborn.

Grandmother steps in to try and help guide the calf across.

Having finally reached the river,

the young mother again chooses a difficult route for her baby.

Oh, dear. He's now blocked by what, for him, is an impossibly high bank.

But this is where being part of a family pays off.

The herd see that he's struggling and return to try to help him.

Everyone gets involved in the rescue,

all trying to save the newborn.

They've done it, thanks to the family working together.

Strong partnerships in this herd will help the inexperienced mother

become better at caring for her calf, giving both a brighter future.

Working together in family groups

is essential to the survival of so many different species.

There's one animal which is famous for its impeccable teamwork.

Ants function like a highly-disciplined army.

Each is clear about its own role and they all work for the same goal.

Nowhere is this teamwork more important

than in the scorching heat of the desert.

In the midday African sun,

very little can survive the soaring temperatures.

But these silver ants have special armoured skin which reflects light.

They can tolerate temperatures that would kill any other land animal.

But even they can only survive out here for a few minutes.

They are in a race to find food

while their predators have gone to ground.

Only by working together as a team

do the ants stand a chance of success.

They've found a victim of heat stroke.

A potential meal.

But will they be able to get it home

before being scorched themselves?

They are nearing their maximum temperature.

A blistering 53 degrees Celsius.

Some can no longer take the heat.

They're running out of time.

They won't make it, not unless they can do something drastic.

By biting off the legs and antennae,

the ants stand a better chance of getting their prey back to the nest.

With a final push, they've made it.

Sacrifices were made along the way,

but the team fulfilled their mission.

From an army of ants to nature's own special forces.

One of the most tactically advanced family partnerships

in the natural world can be found in the sea.

Killer whales.

The ocean's apex predator takes teamwork

and problem-solving to a whole new level.

They employ a range of hunting strategies,

demonstrating high intelligence.

In the Antarctic, a pod of killer whales stays close together

as they scour the sea looking for prey.

There are several potential victims here.

Although they are out of reach.

The solution is highly complex teamwork.

Swimming in perfect formation, they flick their tails in unison

and create a wave that cracks the ice.

They regroup and assess the damage.

A more powerful wave is needed.

With the ice floe breaking up,

they can get a better look at their target.

It's a crabeater seal. Quite vicious. Not their favourite.

A Weddell seal is far more manageable.

They unleash a powerful wave with remarkable accuracy.

The seal is now where the killers want it.

But there's still work to be done.

They need to grab their prey by the tail,

while avoiding its snapping jaws.

Only then will they be able to pull it down and drown it.

Side swipes create violent underwater turbulence, a new tactic.

Blowing bubbles gives cover for others in the team

to lunge at the seal's tail.

Somehow, the seal manages to reach a tiny ice floe.

The killers could easily grab it now.

But rather like a cat with an injured mouse,

they seem to be enjoying the sport.

Yet again, the pod joins forces to dislodge the seal.

Completely exhausted,

the seal hardly has the energy left to pull itself to safety.

For the unfortunate seal,

it's game over...

..falling victim to, without doubt,

one of nature's most lethal partnerships.

Throughout history,

partnerships have also existed between animals and humans.

The majority of these are rather one-sided,

with humans harnessing the skills of wild animals for their own ends.

However, some special relationships do exist

where an understanding between animal and human

has developed which is quite extraordinary.

Bottlenose dolphins make their way to a shoreline in Brazil.

They have forged a remarkable partnership

with the local fishermen here.

Large numbers of mullet come through this area in the early summer.

The problem for the fishermen is that the water is so murky

they can't see where to cast their nets.

The dolphins drive the mullet towards the fishermen

and even signal when to cast their nets with their distinctive dives.

The fishermen claim they can even tell the size of the school

and which way it is travelling

by the vigour and direction of the dive.

The dolphins do all the hard work herding the mullet,

much to the joy of the fishermen.

They can catch many kilos of fish in this way.

The dolphins have no trouble rounding up shoals of fish,

but picking off individuals is more difficult for them.

It's here they benefit from their fellow fishermen.

The nets panic the mullet,

forcing them to break formation.

As the fish make their bid for freedom,

the dolphins seize their chance.

And they're not the only ones to benefit.

One of the most extraordinary partnerships between humans

and wild animals can be found in East Africa.

It's a unique relationship,

which can be traced right back to the 17th century.

This honeyguide bird is calling out...

..not to other birds, but amazingly, to humans.

Its intention is to lead a couple of local Masai to a beehive.

Thanks to its acute sense of smell, it's already found the hive,

but without human help it would find it much harder to reach

the sweet honeycomb inside.

It becomes a game of follow my leader.

As the honeyguide gets closer to the prize,

it changes its call to let them know they're getting warmer.

Here it is,

a hive well-hidden in a tree

and covered by hundreds of African bees.

The boys use smoke to help calm the bees.

Without this smoke, it would be much more painful for either the locals

or the bird to get to the honeycomb.

The honeyguide bird is the only wild animal

known to actually guide people to food in this remarkable way.

These Masai know it's important to keep up their part of the bargain.

The honeyguide bird is rewarded with its share.

A guarantee that this unique partnership can continue.

It's a measure of the huge diversity

and enduring mystery of the natural world

that these extraordinary animal partnerships exist.

I mean, who would've thought it, a bird helping out a tortoise...

..never mind a raven sharing dinner with a wolverine?

It seems these relationships are all about survival.

And without doubt,

having a partner, some more perfect than others,

can make all the difference.