You have started a journey into the heart of the animal world,
where many of nature´s supernatural powers
are waiting to be revealed.
These sensory and physical powers seem out of this world.
Many can be explained by the latest scientific discoveries.
The powers of animals are as extraordinary
as any human mysteries, such as the Bermuda Triangle.
Although science has solved many of nature´s mysteries,
they still deserve the accolade supernatural.
0ur series of dramatic journeys
will investigate different kinds of animal powers.
0n this journey we explore animal perception
and show creatures with senses beyond our own.
(Rapid bleeping)
We confront the limitations of our senses
when we´re plunged into another world.
Here, the senses of others are far superior.
Compared to us, sharks have extrasensory perception.
Extra senses, as well as senses more enhanced than our own.
They can smell blood from over a kilometre away.
And hear struggling sounds pitched below our hearing limits.
They even detect forces beyond any human sense.
Electrosensors surround its mouth.
These detect the electricity of life itself.
Body electricity creates a living aura.
Body openings leak more electricity.
A cut bleeds electricity three metres into the water.
Electrical discharges from metal in salt water provoke an attack.
Sharks are so sensitive,
they mistake the tiniest electrical signal for life.
A five billionth of a volt is enough to merit investigation.
Even unplugged,
enough current flows between different metals to be perceived.
Sharks are not alone in sensing the spark of life.
The stingray is tuned to the body auras of other rays.
The male uses this power to find females hidden in the sand.
His electric sense is so sophisticated,
he can recognise her distinctive aura.
He feels the electricity flow between them.
With eyes on the top of his head, he can´t actually see her.
They are the most electrosensitive of all animals.
Such attraction may climax in an orgy of electrical stimulation.
The torpedo ray has found a stunning use for its electric aura.
Using modified muscles like a battery,
it boosts its body electricity to lethal levels.
It delivers a shocking two-kilowatt bolt,
equivalent to dropping an electric fire into a bath.
Like all living things,
our electric auras only survive as long as we do.
There are many kinds of extra senses.
Some are enhanced versions of our own senses.
The vision of birds far surpasses ours.
Like us, they see full colour.
But many perceive an eerie extra hue.
( # 0pera )
This light is so damaging to us, we protect our eyes from its rays.
To prevent this ultraviolet light harming our skin,
we anoint ourselves with sun block.
0ur appearance must seem bizarre.
The lotion absorbs UV, giving us a strange complexion.
0ur hair and fingernails reflect UV,
making them glow.
To courting king parrots, appearances are everything.
The female eyes up the male´s ultraviolet plumage
before she makes her choice.
Like us, she tends to be choosy.
UV vision also helps birds find a meal.
Most fruit has a waxy coating that reflects ultraviolet.
(Squawking)
Like a neon sign, it shines out to birds in the wild.
Fast food has tempted parrots to take up city life.
0thers have followed the parrots in.
The grey goshawk.
(Dog barking)
Like sun lotion, urine absorbs UV,
making stains highly visible to birds.
Small mammals mark their runs with urine,
leaving evidence of their movements.
This can guide predators to the best hunting grounds.
For parrots, ultraviolet may even act as a last defence.
UV flashes create confusion for the hunter.
(Squawking)
The power of this light fantastic seems almost unlimited.
It may help a lost bird find its way out of the urban jungle.
(Horn blares )
Birds are now thought to see the patterns of polarisation
that radiate from the sun.
These are more noticeable in UV than any other wavelength of light.
Like a map in the sky, they signpost the sun´s position
and may help guide the birds home.
( # 0pera )
This kind of map reading was first discovered in insects.
(Buzzing)
Bees, like us, have full colour vision,
but their range is shifted away from red towards ultraviolet.
Their compound eye limits the detail they actually see.
In Arizona, even the cotton plants have extra senses.
They use them to talk to insects.
When attacked by caterpillars,
the leaves send out a chemical S0S.
Carried on the wind, it´s the signal this wasp has been waiting for.
Soon, others receive the plant´s rallying call.
A whole squadron of wasps is summoned by the plant
and the caterpillars are doomed.
These wasps are parasites.
They inject their eggs with a well-aimed stab.
Each lethal injection will spawn an alien invasion
that consumes the caterpillar and saves the plant.
The plant´s chemical scents also attract pollinators.
These humble insects use chemical extra senses
in a remarkable way.
Returning bees carry a chemical identity pass
and are security checked by guard bees,
the defenders of the colony.
Increasing vibrations provoke the guards
to release a warning from their sting.
This chemical message alerts the hive to the growing threat.
The guard investigates.
Vibrations and synthetic smells all provoke attack.
And these bees are hyper-reactive.
They´re the descendants of a Brazilian experiment
that crossed honey bees with African strains.
The killer bee has now invaded southern USA.
The poisonous sting pumps out a pheromone.
This goads the swarm into a stinging frenzy.
With their extra senses enhanced by human breeding,
they´re a killing machine.
Running is only for the fit.
Killer bees can give chase up to a mile.
Even here, there´s no escape.
The bees may wait for over an hour,
perseverance derived from their African ancestors.
Killer bees were the result of a disastrous human experiment,
but killer plants exist in nature.
They even talk to each other.
Acacias can warn their neighbours of impending danger.
When eaten by a browsing animal, the leaves release a gas
that conveys a message to nearby trees.
When the leaves receive the signal, they react in a remarkable way.
Toxins spread throughout the leaves.
In just 30 minutes, the leaves are laced with poisonous tannins.
To avoid poisoning, giraffes and antelope
only graze for short periods before they move on.
Many of the secret powers of plants have just been revealed.
The more we discover, the more like animals they seem.
Distort our perception of time and the similarities become clearer.
Even though they lack specialised nerve cells,
they do have a primitive nervous system
that transmits electrical signals.
Cut the grass and it reacts, nervously.
Electricity fires a warning bolt.
This electrical impulse tells the grass to grow
and become more toxic.
It responds as though we were a grazing animal and fights back.
Climbers, like these passion vines,
have tendrils sensitive to the slightest touch.
The electric message passes through the plant cells.
The tendrils react by growing a spring-coiled clasp.
If plants are so sensitive,
how do household plants react to our attentions?
Deprived of outside stimulation,
a caring touch actually promotes growth.
Even tiny voice vibrations may excite a house plant
and trigger stretch-sensitive cells responsible for growth.
Best of all, the carbon dioxide from our breath is food.
For plants, it´s good to talk.
Plants are so sensitive, some even sense the coming of storms.
(Thunderclap)
A bird´s extra senses include hearing.
They detect thunder at a pitch far below our hearing limits.
These infrasounds carry hundreds of kilometres
and may warn of bad weather ahead.
Hearing infrasound may give birds another surprising power.
To migrate successfully, pelicans must find
the twisting columns of hot air known as thermals.
These create a storm of infrasound.
They also hear the infrasound from office air conditioning, cars,
and even underground gas mains.
Although inaudible to us, these sounds can make us feel ill.
(Siren wails)
By listening for the rumble of churning air,
the pelicans can fly towards the thermal.
(Rumbling)
0nce they reach the base, they rise in the updraught.
The thermal may spiral them 3,000 metres above the ground.
At the top, they peel off and glide away to catch their next free ride.
Like this, they float on air from Europe to Africa.
(Snorting)
Elephants were the first land creatures
known to have the power to generate infrasound.
(Grunting)
Their secret rumbles carry ten kilometres or more
and act as a rallying call.
(Rumbling grunts )
The sounds are also used as greetings and for other social calls.
(Grunting)
Since this landmark discovery, other animals have been found
that make sounds beyond our perception.
Hippos are now known to use infrasound too.
They also have a whole private repertoire of other calls.
(Grunting and rumbling)
Even though these sounds lie within our auditory range,
the water surface acts as a barrier, preventing us ever hearing them.
The male uses these private calls to communicate with the female.
(Clicking)
Advances that are not always welcome.
(Grunting)
The bellow we hear is expelled through the nostrils
and contains infrasound.
(Grunting)
The call also radiates underwater and is picked up by the jaw.
In air, infrasound carries five kilometres.
It´s picked up by the ear.
Both sounds leave together,
but in water, sound travels five times faster.
In air, it lags behind.
Hippos are thought to exploit this time lag
to judge how close a rival may be.
They can hear underwater infrasound 30 kilometres away.
When they finally meet, the outcome can be spectacular.
As well as hippos, many other animals are now known to share
the sonic power that was first discovered in elephants.
Rhinos warn their offspring of danger with these infrasounds too.
(Grunting)
(Rumbling)
(Growling)
Another extrasensory power in elephants has been discovered.
It lies in their feet.
(Trumpeting)
When threatened, they resort to seismic communication.
These shock waves carry to herds 50 kilometres away,
alerting them to the threat.
The tremors travel up the leg and are transmitted to the inner ear.
But sometimes an elephant´s power deserts him.
(Trumpeting)
No animal uses extrasensory sound more effectively
than the dolphin.
Many of its calls are pitched far above our hearing range.
Like a ship´s sonar, it sends out these ultrasounds
and creates a picture from the returning echoes.
(Clicking)
Its forehead focuses the sound into a beam.
Used like a sonic torch, it scans for prey.
To gather more information, it ups the pulse rate,
penetrating its prey like an X-ray.
There are reports of shipwreck victims attracting dolphins.
Their sonar penetrates us too,
making our skeletons and lungs visible.
As mammals, we must appear similar to them.
Dolphins find pregnant woman particularly fascinating.
Its sonar acts like an ultrasound scan.
(Heart beats )
It even hears the embryo´s heartbeat.
Perhaps they recognise similarities here, too.
Sharks feature in another dolphin story.
When people are in trouble,
dolphins are supposed to ward off sharks.
They repel with high-speed blows.
Stories also tell of them saving people from drowning,
bringing them to the surface, as though aware of the danger.
Some believe there´s a special bond between us.
Science is more rational.
Dolphins support their own injured at the surface,
for they too can drown.
Perhaps our struggles trigger this behaviour.
Alternatively, we may simply be a novel plaything for them.
Whatever the truth, the known extrasensory powers
of these incredible creatures
are as remarkable as any myths or legends.
Extra senses are only one kind of supernatural power.
There are many others.
0ur next supernatural journey
will explore animal powers at the outer limits of endurance.