Pets: Wild at Heart (2015): Season 1, Episode 2 - Secretive Creatures - full transcript
Our favourite pets are among the
most amazing animals on Earth.
They've taken to a domestic life
and become our perfect companions.
But still their wild
senses remain intact.
They may have been tamed
for thousands of years...
...but they were wild
animals for millions more.
Some were smart and supreme predators.
Others were alert
and fleet-footed prey.
- David Tennant Espa?a -
- www.davidtennant.es -
Traducido por:
EMDM
Whatever their origins, they still
have astonishing hidden powers.
They use senses different from our own
and communicate in ways
we could never imagine.
Take a closer look...
and discover the true
animal sharing your home.
A creature just a
wing-beat from the wild.
- David Tennant Espa?a -
- www.davidtennant.es -
Sincronizado por:
EMDM
All our pets possess
an array of wild senses,
and this hamster is about to
use his on a secret mission.
He has waited until the dead of night,
while the rest of the
household is sleeping.
Although not exactly the best of
climbers, instinct drives him on.
To avoid predators, he travels by night,
a time when his eyesight
comes into its own.
But he also uses his impressive
whiskers to build up a 3D picture.
He uses sounds pitched
above our hearing,
and his supersensitive
nose analyses every smell.
He uses this information to create
a sensory map that in the wild
would guide him across
miles of featureless desert.
But his navigational
equipment doesn't stop there.
Wherever he goes, glands on
his belly lay down a scent that
acts like a paper trail, allowing
him to retrace his steps back home.
For a burrowing creature,
holes are irresistible.
In a hamster ball, he's astute
enough to control direction.
Although some aspects of our
modern world are too challenging
even for this hamster.
But his incredible senses can
also get him out of trouble.
Using high-pitched
calls that we can't hear,
he detects the drop by the
sound of the returning echoes.
Disaster averted, he
continues his secret mission -
one he must complete before daybreak!
For dogs, too, getting out and
about excites their wild senses -
and for such intelligent animals,
you can't beat a road trip.
While we are obsessed
with visual landmarks,
they focus only on scents.
We have a measly six
million smell receptors,
but a dog's nose contains 300 million.
They use it to unravel stories
about the world around them -
predictably, most are about food.
40 times more of their
brain than ours is devoted
to deciphering smells.
They home in on those
with special significance -
a single chemical,
aldehyde, found in blood,
makes this one-time hunter drool.
There is a way to bring
this smelly world to life.
Schlieren photography visualises
the air currents that carry odours
and shows the remarkable
workings of a dog's nose.
Dogs breathe out through the
side slits in their nostrils.
As the expelled air rotates, it
helps draw more scent into the nose.
This two-way current helps a dog
gather scent almost continuously.
But that's not all...
A male can smell a female on heat
at concentrations of
one part in a trillion.
Licking helps capture
more of her alluring scent.
His tongue takes the odour to a
second smell organ in the mouth,
hardwired to the brain and
tuned to these sexual pheromones.
It's love at first sniff.
For dogs, being a passenger
rivals any wild experience.
But it can be tinged
with disappointment too.
The streets of Paris may be
full of romantic promise...
...but pet dogs are seldom
in control of their destiny.
Love may be in the air, but
it's so rarely fulfilled.
Cats are much more free
to follow their noses,
and they've been shown to investigate
several hundred odours each hour.
And smells can sometimes take
them to a drug-fuelled gathering.
He can detect the scent from catnip
in just one part in a billion.
Just a few bites of
this mind-altering plant
and he falls under its alluring spell.
Its volatile oils
imitate a sexual hormone
and cause a potent
reaction in its brain.
Eight out of ten adult cats
find it totally seductive,
and the strange response is inherited.
Even big cats, such
as leopards and tigers,
react in the same intoxicated way.
For cats, catnip may
be a recreational drug,
but it's totally harmless...
...although there are
always some who overindulge!
It's not all peace and love.
Cats are solitary by nature
and don't like sharing.
After about ten minutes, the
cats come back down to earth.
But a cat's nose is not
its primary sensory tool -
its eyes are highly
tuned to fast-moving prey.
Fish are especially mesmerising -
especially those
tantalisingly out of reach.
Goldfish have their own
extraordinary abilities.
They appeared in China
over 1,000 years ago,
having been selectively
bred from wild silver carp.
Around 250 years ago,
the stargazer appeared.
Legend has it that they were
created so that their eyes would
always be directed in wonder
towards the glorious emperor.
Experiments revealed that
goldfish recognise their owners.
They have surprisingly good memories too
- five months or more.
Their extendable jaw helps suck up food.
The edible bits are ground up on
tiny teeth at the back of the mouth,
while the rest is spat out.
The stargazer's protruding
eyes are easily damaged,
so they should only
be kept by specialists.
But goldfish have astonishing
powers of regeneration,
and an injured eye can re-grow.
Goldfish see "far-red"
- a colour we can't see
that penetrates murky pond water.
But it's not their only sensory tool
- a row of sensors,
known as the lateral line,
pick up water movements.
The filming technique
that visualised airflow
shows the eddies created
by a swimming goldfish.
These mini-currents are picked up
by the lateral line of other fish
and this helps them swim
as a coordinated shoal.
It detects predators too
- a touch sends a warning shockwave.
Goldfish even use ripples to flirt!
Just as our pet fish can
detect water currents,
our favourite pet birds can
sense the movements of air.
A budgerigar responds to
surrounding air currents by adjusting
and controlling her flight.
Nerve endings at the base of her
feathers continually feed back
the information she needs.
In this way, she detects
and avoids turbulent air...
...and seeks out rising currents.
By sensing the air, she
maintains flight efficiency.
And budgies have yet
another sensory secret...
In their courtship, good
looks are everything.
But after her flight, she's too
occupied in preening to care.
But her admirer has ways
to get himself noticed...
She sees more subtleties
of colour than we can,
and she detects ultraviolet too
- a colour invisible to us.
Under UV, his plumage takes
on a very different look.
The yellow pigments in his
crown and cheeks absorb UV,
and the effect is stunning.
But unless she looks, it's all in vain.
He fluffs up his feathers
to show off his true colours,
but she still gives
him the cold shoulder.
It seems every relationship
needs a nudge sometimes.
Now he has her attention!
Females prefer males
that really shine -
the more his plumage absorbs UV,
the fitter and healthier he is.
She's impressed, and
invites him to preen.
The budgie's sensory world
continues under our radar -
as it does with so many of our pets.
The wandering hamster is
completing his secret quest.
It's taken half the night,
but he's found exactly
what he was looking for!
He stuffs his cheeks with
as much as he can carry.
And he can carry a lot!
But there's still one
remaining challenge -
to get back to his nest.
It's no mean feat.
By using the mental map he
created on his outward journey,
he sets off in the right direction,
and soon picks up the scent
trail he previously laid.
It's then a matter of
following his nose to his cage.
Wherever a hamster lives,
there's no place like home.
And, like all homes, there is
always room for improvement.
His pouches are designed to
keep their contents bone dry -
his new bedding is as
fresh as when gathered.
Soon, thanks to his wild
senses, this escapologist will be
tucked up in his newly-made bed
with his owner none the wiser.
Hamsters can go about
their business unnoticed,
but some pets demand a
more hands-on approach.
Anyone who owns a horse is
in a unique relationship.
At its heart are the signals and
senses a horse uses in the wild.
When a child grooms her pony,
she unconsciously gives a message
all horses understand.
The moving brush mimics
the teeth of another horse,
and it's a sign of friendship.
Horses only groom close relatives
or their very best friends.
Nibbling the base of the
neck lowers the heart rate,
and has a calming effect.
Friendships create harmony in a
herd, but take time to maintain,
so horses rarely have more
than three lifelong friends.
To become a successful human friend
requires being in tune
with a horse's wild ways.
When a mare's about to give birth,
her knowing owner often
separates her from the herd -
as a prey animal, she feels
vulnerable at this time.
She waits until there is no-one around,
just as wild horses wait
until there are no predators.
She then prepares the
ground for the birth.
It's a dangerous time for the mare
- foals are born fully formed
and can be difficult to deliver.
In the end, it happens quickly.
In these first precious
moments, she learns his smell
and creates a lasting bond.
She knows he must get to his
feet as quickly as possible -
wild predators could be lurking.
He has to take his first
steps within minutes,
and become fully mobile
over the next few hours.
He even tries to run
- a vital survival skill.
As he suckles, he bonds to
his mother's distinctive scent.
Soon, the world outside beckons -
he's ready to test
out those fragile legs.
As his confidence grows,
he practises kicking
imaginary predators.
Young foals must quickly learn
the rules governing horse society -
even rolling has its own etiquette.
Foals must roll after their mother.
There are even rules
on dealing with flies -
an annoying problem
through the summer months.
To fight the plague, horses
are equipped with fly-whisks,
but they are most useful for
helping others, such as her foal.
So the mothers are driven to distraction
while their foals are
kept relatively fly-free.
The foals must learn that it's
horse manners to stand end to end.
He might not have grown
the perfect fly-whisk yet,
but at least he's making the effort.
Learning to empathise is
important for making friends -
a vital skill for herd life.
Horses have been human
companions for 10,000 years,
but they're not the only herd animal
with a long history of domestication.
The high Andes of South America.
Here, guinea pigs
still greet their owners
with a chorus of anticipation -
a ritual that goes back 7,000 years.
They are the most vocal of all our pets,
and when food's on its way, they
can hardly contain themselves.
They also pogo with excitement
- a habit known as "popcorning".
Although guinea pigs are
eaten on special occasions,
they're valued like pets,
and are even credited with
magical healing powers.
They came from a wild
animal known as a cavy,
and organise themselves
into small herds,
just like their wild relatives.
A harem of several females is
watched over by a dominant male.
Every chattering call has meaning.
This bubbling means they're
enjoying themselves -
it's most often made while eating.
But, when they're cross,
they let everyone know.
They make warning calls too.
And the male purrs seductively
when wooing a female.
But guinea pigs breed so readily,
most are already pregnant,
and don't easily fall for his charms.
If she's not in a romantic mood,
she'll gladly give him the run-around.
Perhaps because they're so chatty,
guinea pigs are now
popular the world over.
But, keep a male and female
together and the inevitable happens.
Her young are born fully developed,
and giving birth to such large
babies can be a challenge.
The male attends the birth
- an unusual habit for rodents.
This moment has rarely been filmed
and such paternal interest
is quite a revelation.
Her baby is born in an amniotic sac,
which his mother bites through
to allow him to breathe freely.
Soon, three young make an appearance,
all with fully functional senses,
and ready to run from predators.
In the wild, such active
youngsters could easily get lost.
But this new father has a caring side.
He looks for any that have strayed
and sends them back to their mother.
But there's another reason
the male attends the birth.
Guinea pigs can become
pregnant almost immediately,
and he's perfectly positioned to
make the most of the opportunity.
A mother's smell, sounds and nurturing
give her young a sense of security
and show them how to behave.
So, what happens if your
mum doesn't want you?
This puppy was rejected
by his mother at birth,
but he's had the good fortune
to be adopted by a cat.
Her mothering hormones are so
strong she accepts him as her own.
The puppy was born on the same day
and he happily adapts to his new family.
But kittens live by different
social rules, even when they suckle.
They nametag teats with
their own individual scent,
and return to it each time.
This simple rule maintains peace
and harmony during feeding time.
But for dogs, pack life
requires fighting for your share
in the rough and tumble
of competing mouths.
This puppy breaks all of
the cats' social conventions.
His wild instincts express themselves,
despite his unusual family.
Ultimately, the puppy's needs and
his foster mum's nurturing feelings
overcome any differences...
for now.
But as adults, these top predators
will differ in almost every detail.
When a cat drinks, he
uses a refined technique.
The rough upper side of
his tongue curls downwards
to pick up the liquid
using surface tension.
It pulls the column of
milk up into his mouth
without making any mess at all.
A solitary hunter can
afford to take his time -
it's a different matter
when you hunt as a pack.
A dog also pulls a
column into his mouth,
but, unlike cats, he shapes
his tongue into a ladle
to slosh more liquid in.
For pack animals,
beating your rivals to a drink is
more important than cleanliness.
X-ray shows how the
milk is thrown backwards
at five times the force of gravity,
and his mouth shuts like
a trap as it is swallowed.
It might be effective,
but it's far messier than the cat.
The two predators could
hardly be less alike,
but those brought up together
still find ways to communicate.
This cat scent-marks his
canine pal by rubbing him,
just as he would another cat.
But cats choose their
moments of affection,
and independence soon shows itself.
Cats are the only pet
that hunts independently,
and he's well equipped for the part.
Rat sounds are above our hearing,
but well within the cat's range.
And his superb night
vision pierces the gloom.
Sensory hairs on his paws test each
step, so as not to make a sound.
His gaze never leaves his prey.
Just like their wild counterparts,
housecats stalk as close as they can.
He freezes.
Any movement will trigger the attack.
Something has to give.
But this rat bites back!
Despite formidable senses, even wild
cats miss four times out of five.
Dogs rarely get to hunt, but
their senses are still razor sharp.
And they combine natural
skills with intelligence.
A well-fed dog looks for
somewhere to bury a bone,
just as he would in the wild.
But he's smart enough to
know he's being watched...
...and chooses somewhere out of sight.
Caching food is common among wolves
as they hedge their bets
against leaner times.
They remember their hideaways,
and return to them when hungry.
But dogs rarely retrieve
their buried treasures,
and this one won't ever get the chance!
In our world, the wild and
the domestic are so mixed up,
dogs often make some fundamental errors.
Burying bones, even in the wrong place,
is one of a dog's
favourite natural pastimes.
But carrying sticks
is even more popular.
In the wild, they bring
food back to their young,
and the instinct to
carry is still there.
Now, they even retrieve sticks
from water just for the fun of it.
Once out, human companions
need to move away fast.
In a single shake, he
can lose 70% of the water.
But he must rotate his body fast
enough to fling it from his fur.
Shaking starts at his head, but the
energy wave travels down his body.
His skin and fur whip the water
away as the shake changes direction.
The force at the hair tips can
reach 70 times that of gravity.
Small dogs must shake
faster than larger dogs
to achieve the same spin-dry result.
Stand nearby and
you're in for a soaking!
It's not just dogs that can make a mess.
Place a buck rabbit in a new cage,
and it's best to stand well back.
He makes himself at home by
spraying his scent everywhere.
He also scent-marks
with his cheek glands
and spreads his aroma by digging.
His actions make perfect sense
among wild-living rabbits.
On Rabbit Island in Japan,
feral pet rabbits live
a near-natural life
a whisker away from human visitors.
The same scent-marking
behaviour goes on here.
Any strange new objects
are immediately marked
so they become familiar.
Males spray females as they
compete with other males.
But, with so much competition,
it's every buck for himself.
Fights get quite heated
- they're not such cuddly bunnies now.
But the winners get the chance to mate.
Even though some need
time to get the hang of it!
After mating, the doe prepares the nest,
gathering bedding from wherever she can.
But, for the very best nest
lining, she needn't look far.
Nothing beats a blanket of fur.
Any pet given the
chance to live naturally
soon expresses their wild instincts.
Cats on this Japanese island
live a semi-wild existence,
but in higher numbers than
ever found in the wild.
A wild tomcat has just a
few females in his territory,
but here, cats are forced together
as they scavenge from fishermen.
They use their full
repertoire of catcalls
during the inevitable squabbles.
They make over 100 sounds
in all, some subtle -
some not so subtle!
As they scuffle over feeding rights,
young cats are at a disadvantage
and are often chased away.
Cats don't expect to share their food.
In nature they hunt alone,
and what they catch is theirs.
This kitten is allowed to push her
luck so she may be a young relative.
But cats seldom give up a meal.
Most look for a secluded
spot away from competitors,
but they're rarely left alone.
A hiss is universally understood,
but cats also know where
they are in the social order.
A kitten may hiss all he likes,
but in cat society, age comes first.
Cats also leave scent messages.
Males spray a pungent
note on key landmarks
to announce their presence.
They use other scent marks too.
Glands on the cheeks deposit
a unique personal odour.
They also mark those
they regard as friends -
just as pet cats rub scent
on the legs of human owners.
Scratching applies yet more
scent from glands on their feet.
But some cats prefer not
to announce their presence -
submissive cats bury
the smelly evidence,
just as they do in a litter tray.
In our homes, cats show
their subservience to us
by hiding their deposits.
Although few take it to this extreme!
This cat taught himself the technique.
If only he could learn
to pull the flush!
With no litter to cover his tracks,
he does what comes naturally -
make the scratching movements
that would normally bury his smell.
Whether scents are
concealed or openly flaunted,
most pets use odours to communicate.
But no-one uses smell
messaging quite like dogs.
In Cuzco, Peru, pet dogs are
allowed to roam the streets at will,
and can work out what every
other city dog is up to
using their noses.
Lampposts are irresistible for any dog,
but this scent-marking is
surprisingly sophisticated.
They act like notes
posted around the city,
and dogs deliberately save up their pee
to ensure there's enough to go round.
These messages show who they are
and, by the rate the smell decays,
how recently they've visited.
Dogs travelling together
over-mark each other's scent
to advertise the size of their pack.
It allows everyone to keep tabs on
the whereabouts of everyone else.
Dogs that spray higher are
more dominant and best avoided.
But plenty are immediately
recognised as friends.
In these playful encounters,
they associate the dogs they meet
with the scent marks
they've come across.
Besides scent, there are other ways
to find your mates in a big city.
A barking dog forces air through
his vocal cords at over 100mph.
The sound can exceed 110 decibels...
...louder than a passing jet.
Wolves rarely bark,
so this way of communicating
is a product of domestication.
And dogs produce a
complex variety of barks.
A rapid string of four to
five barks is a rallying call.
Hearing another dog bark increases
their heart rate, ready for action.
It doesn't take long for
the message to get around.
Once they find each other,
barking appears contagious.
One or two short, high-pitched
barks are used to greet a friend.
More continuous, lower-pitched
barks alert the pack to a stranger.
When the talking's over,
fights can break out.
It may look serious, but these
skirmishes are mostly for show
and rarely lead to bloodshed.
Their bark really is
worse than their bite.
We have only just begun to
decipher the dog's hidden messages.
But, using all their complex signals,
the dogs of Cuzco have created a
parallel world in a human city -
one known only to them.
Mutt or pampered pet,
street fighter or stray,
the dogs use their natural abilities
to sort out their differences
and find ways to get along.
They live in a secret
world of communication,
even though, at the end of the day,
most have human homes to return to.
Living together is all
about communication,
and for horses, herd life
would be impossible without it.
In the Camargue in France, the
behaviour of semi-wild horses
shows why they make such
perfect human companions.
A dominant mare leads a herd of
several females and their offspring.
This willingness to be led
is the reason a horse responds
so readily to our bidding.
The lead mare takes them
to a dust-bathing spot -
an important part of
their daily routine.
The leader rolls first.
As foals, they learnt
that there's a strict order
to even the simplest activity.
Prey animals always
need someone on watch.
The stallion's role is to protect
the herd, and he always rolls last.
The lead mare gains her position
through age and experience -
finding the best food and water is
one of her many responsibilities.
She continually communicates with
the herd, mostly using her ears.
They point towards a horse
she's trying to identify,
but she also uses the position of
her ears to convey her feelings.
16 muscles control each ear,
allowing subtle changes of expression.
If they're flopped down, it
means she's relaxed and happy.
When she's interested in
something, she pricks them forward.
And she pins them back
when she's annoyed.
If that doesn't produce the required
reaction, she follows with a charge.
Just pinning back the ears
is usually enough to
get the herd moving.
As well as responding to ear positions,
horses are very sensitive
to each other's touch,
and react to pressures too
light for humans to feel.
Riders tap into this sensitivity,
by a heel pressed against a side,
or minute changes of position.
Although horses communicate
in so many different ways,
it's friendship bonds that
lie at the heart of the herd.
And the very best friends
show their affection
by blowing in each other's noses.
Young stallions even practise
their fighting moves on a friend.
It's a chance to safely
try out techniques
that one day will be used in earnest.
But, for now, they're
the best of buddies.
Like all our animal companions,
horses possess
extraordinary wild abilities.
But all our pets are special
in their own unique way.
They find a way to live alongside
us, as part of the family,
but in a very different world.
Whether in play,
or through incredible senses,
they will always be wild at heart.
most amazing animals on Earth.
They've taken to a domestic life
and become our perfect companions.
But still their wild
senses remain intact.
They may have been tamed
for thousands of years...
...but they were wild
animals for millions more.
Some were smart and supreme predators.
Others were alert
and fleet-footed prey.
- David Tennant Espa?a -
- www.davidtennant.es -
Traducido por:
EMDM
Whatever their origins, they still
have astonishing hidden powers.
They use senses different from our own
and communicate in ways
we could never imagine.
Take a closer look...
and discover the true
animal sharing your home.
A creature just a
wing-beat from the wild.
- David Tennant Espa?a -
- www.davidtennant.es -
Sincronizado por:
EMDM
All our pets possess
an array of wild senses,
and this hamster is about to
use his on a secret mission.
He has waited until the dead of night,
while the rest of the
household is sleeping.
Although not exactly the best of
climbers, instinct drives him on.
To avoid predators, he travels by night,
a time when his eyesight
comes into its own.
But he also uses his impressive
whiskers to build up a 3D picture.
He uses sounds pitched
above our hearing,
and his supersensitive
nose analyses every smell.
He uses this information to create
a sensory map that in the wild
would guide him across
miles of featureless desert.
But his navigational
equipment doesn't stop there.
Wherever he goes, glands on
his belly lay down a scent that
acts like a paper trail, allowing
him to retrace his steps back home.
For a burrowing creature,
holes are irresistible.
In a hamster ball, he's astute
enough to control direction.
Although some aspects of our
modern world are too challenging
even for this hamster.
But his incredible senses can
also get him out of trouble.
Using high-pitched
calls that we can't hear,
he detects the drop by the
sound of the returning echoes.
Disaster averted, he
continues his secret mission -
one he must complete before daybreak!
For dogs, too, getting out and
about excites their wild senses -
and for such intelligent animals,
you can't beat a road trip.
While we are obsessed
with visual landmarks,
they focus only on scents.
We have a measly six
million smell receptors,
but a dog's nose contains 300 million.
They use it to unravel stories
about the world around them -
predictably, most are about food.
40 times more of their
brain than ours is devoted
to deciphering smells.
They home in on those
with special significance -
a single chemical,
aldehyde, found in blood,
makes this one-time hunter drool.
There is a way to bring
this smelly world to life.
Schlieren photography visualises
the air currents that carry odours
and shows the remarkable
workings of a dog's nose.
Dogs breathe out through the
side slits in their nostrils.
As the expelled air rotates, it
helps draw more scent into the nose.
This two-way current helps a dog
gather scent almost continuously.
But that's not all...
A male can smell a female on heat
at concentrations of
one part in a trillion.
Licking helps capture
more of her alluring scent.
His tongue takes the odour to a
second smell organ in the mouth,
hardwired to the brain and
tuned to these sexual pheromones.
It's love at first sniff.
For dogs, being a passenger
rivals any wild experience.
But it can be tinged
with disappointment too.
The streets of Paris may be
full of romantic promise...
...but pet dogs are seldom
in control of their destiny.
Love may be in the air, but
it's so rarely fulfilled.
Cats are much more free
to follow their noses,
and they've been shown to investigate
several hundred odours each hour.
And smells can sometimes take
them to a drug-fuelled gathering.
He can detect the scent from catnip
in just one part in a billion.
Just a few bites of
this mind-altering plant
and he falls under its alluring spell.
Its volatile oils
imitate a sexual hormone
and cause a potent
reaction in its brain.
Eight out of ten adult cats
find it totally seductive,
and the strange response is inherited.
Even big cats, such
as leopards and tigers,
react in the same intoxicated way.
For cats, catnip may
be a recreational drug,
but it's totally harmless...
...although there are
always some who overindulge!
It's not all peace and love.
Cats are solitary by nature
and don't like sharing.
After about ten minutes, the
cats come back down to earth.
But a cat's nose is not
its primary sensory tool -
its eyes are highly
tuned to fast-moving prey.
Fish are especially mesmerising -
especially those
tantalisingly out of reach.
Goldfish have their own
extraordinary abilities.
They appeared in China
over 1,000 years ago,
having been selectively
bred from wild silver carp.
Around 250 years ago,
the stargazer appeared.
Legend has it that they were
created so that their eyes would
always be directed in wonder
towards the glorious emperor.
Experiments revealed that
goldfish recognise their owners.
They have surprisingly good memories too
- five months or more.
Their extendable jaw helps suck up food.
The edible bits are ground up on
tiny teeth at the back of the mouth,
while the rest is spat out.
The stargazer's protruding
eyes are easily damaged,
so they should only
be kept by specialists.
But goldfish have astonishing
powers of regeneration,
and an injured eye can re-grow.
Goldfish see "far-red"
- a colour we can't see
that penetrates murky pond water.
But it's not their only sensory tool
- a row of sensors,
known as the lateral line,
pick up water movements.
The filming technique
that visualised airflow
shows the eddies created
by a swimming goldfish.
These mini-currents are picked up
by the lateral line of other fish
and this helps them swim
as a coordinated shoal.
It detects predators too
- a touch sends a warning shockwave.
Goldfish even use ripples to flirt!
Just as our pet fish can
detect water currents,
our favourite pet birds can
sense the movements of air.
A budgerigar responds to
surrounding air currents by adjusting
and controlling her flight.
Nerve endings at the base of her
feathers continually feed back
the information she needs.
In this way, she detects
and avoids turbulent air...
...and seeks out rising currents.
By sensing the air, she
maintains flight efficiency.
And budgies have yet
another sensory secret...
In their courtship, good
looks are everything.
But after her flight, she's too
occupied in preening to care.
But her admirer has ways
to get himself noticed...
She sees more subtleties
of colour than we can,
and she detects ultraviolet too
- a colour invisible to us.
Under UV, his plumage takes
on a very different look.
The yellow pigments in his
crown and cheeks absorb UV,
and the effect is stunning.
But unless she looks, it's all in vain.
He fluffs up his feathers
to show off his true colours,
but she still gives
him the cold shoulder.
It seems every relationship
needs a nudge sometimes.
Now he has her attention!
Females prefer males
that really shine -
the more his plumage absorbs UV,
the fitter and healthier he is.
She's impressed, and
invites him to preen.
The budgie's sensory world
continues under our radar -
as it does with so many of our pets.
The wandering hamster is
completing his secret quest.
It's taken half the night,
but he's found exactly
what he was looking for!
He stuffs his cheeks with
as much as he can carry.
And he can carry a lot!
But there's still one
remaining challenge -
to get back to his nest.
It's no mean feat.
By using the mental map he
created on his outward journey,
he sets off in the right direction,
and soon picks up the scent
trail he previously laid.
It's then a matter of
following his nose to his cage.
Wherever a hamster lives,
there's no place like home.
And, like all homes, there is
always room for improvement.
His pouches are designed to
keep their contents bone dry -
his new bedding is as
fresh as when gathered.
Soon, thanks to his wild
senses, this escapologist will be
tucked up in his newly-made bed
with his owner none the wiser.
Hamsters can go about
their business unnoticed,
but some pets demand a
more hands-on approach.
Anyone who owns a horse is
in a unique relationship.
At its heart are the signals and
senses a horse uses in the wild.
When a child grooms her pony,
she unconsciously gives a message
all horses understand.
The moving brush mimics
the teeth of another horse,
and it's a sign of friendship.
Horses only groom close relatives
or their very best friends.
Nibbling the base of the
neck lowers the heart rate,
and has a calming effect.
Friendships create harmony in a
herd, but take time to maintain,
so horses rarely have more
than three lifelong friends.
To become a successful human friend
requires being in tune
with a horse's wild ways.
When a mare's about to give birth,
her knowing owner often
separates her from the herd -
as a prey animal, she feels
vulnerable at this time.
She waits until there is no-one around,
just as wild horses wait
until there are no predators.
She then prepares the
ground for the birth.
It's a dangerous time for the mare
- foals are born fully formed
and can be difficult to deliver.
In the end, it happens quickly.
In these first precious
moments, she learns his smell
and creates a lasting bond.
She knows he must get to his
feet as quickly as possible -
wild predators could be lurking.
He has to take his first
steps within minutes,
and become fully mobile
over the next few hours.
He even tries to run
- a vital survival skill.
As he suckles, he bonds to
his mother's distinctive scent.
Soon, the world outside beckons -
he's ready to test
out those fragile legs.
As his confidence grows,
he practises kicking
imaginary predators.
Young foals must quickly learn
the rules governing horse society -
even rolling has its own etiquette.
Foals must roll after their mother.
There are even rules
on dealing with flies -
an annoying problem
through the summer months.
To fight the plague, horses
are equipped with fly-whisks,
but they are most useful for
helping others, such as her foal.
So the mothers are driven to distraction
while their foals are
kept relatively fly-free.
The foals must learn that it's
horse manners to stand end to end.
He might not have grown
the perfect fly-whisk yet,
but at least he's making the effort.
Learning to empathise is
important for making friends -
a vital skill for herd life.
Horses have been human
companions for 10,000 years,
but they're not the only herd animal
with a long history of domestication.
The high Andes of South America.
Here, guinea pigs
still greet their owners
with a chorus of anticipation -
a ritual that goes back 7,000 years.
They are the most vocal of all our pets,
and when food's on its way, they
can hardly contain themselves.
They also pogo with excitement
- a habit known as "popcorning".
Although guinea pigs are
eaten on special occasions,
they're valued like pets,
and are even credited with
magical healing powers.
They came from a wild
animal known as a cavy,
and organise themselves
into small herds,
just like their wild relatives.
A harem of several females is
watched over by a dominant male.
Every chattering call has meaning.
This bubbling means they're
enjoying themselves -
it's most often made while eating.
But, when they're cross,
they let everyone know.
They make warning calls too.
And the male purrs seductively
when wooing a female.
But guinea pigs breed so readily,
most are already pregnant,
and don't easily fall for his charms.
If she's not in a romantic mood,
she'll gladly give him the run-around.
Perhaps because they're so chatty,
guinea pigs are now
popular the world over.
But, keep a male and female
together and the inevitable happens.
Her young are born fully developed,
and giving birth to such large
babies can be a challenge.
The male attends the birth
- an unusual habit for rodents.
This moment has rarely been filmed
and such paternal interest
is quite a revelation.
Her baby is born in an amniotic sac,
which his mother bites through
to allow him to breathe freely.
Soon, three young make an appearance,
all with fully functional senses,
and ready to run from predators.
In the wild, such active
youngsters could easily get lost.
But this new father has a caring side.
He looks for any that have strayed
and sends them back to their mother.
But there's another reason
the male attends the birth.
Guinea pigs can become
pregnant almost immediately,
and he's perfectly positioned to
make the most of the opportunity.
A mother's smell, sounds and nurturing
give her young a sense of security
and show them how to behave.
So, what happens if your
mum doesn't want you?
This puppy was rejected
by his mother at birth,
but he's had the good fortune
to be adopted by a cat.
Her mothering hormones are so
strong she accepts him as her own.
The puppy was born on the same day
and he happily adapts to his new family.
But kittens live by different
social rules, even when they suckle.
They nametag teats with
their own individual scent,
and return to it each time.
This simple rule maintains peace
and harmony during feeding time.
But for dogs, pack life
requires fighting for your share
in the rough and tumble
of competing mouths.
This puppy breaks all of
the cats' social conventions.
His wild instincts express themselves,
despite his unusual family.
Ultimately, the puppy's needs and
his foster mum's nurturing feelings
overcome any differences...
for now.
But as adults, these top predators
will differ in almost every detail.
When a cat drinks, he
uses a refined technique.
The rough upper side of
his tongue curls downwards
to pick up the liquid
using surface tension.
It pulls the column of
milk up into his mouth
without making any mess at all.
A solitary hunter can
afford to take his time -
it's a different matter
when you hunt as a pack.
A dog also pulls a
column into his mouth,
but, unlike cats, he shapes
his tongue into a ladle
to slosh more liquid in.
For pack animals,
beating your rivals to a drink is
more important than cleanliness.
X-ray shows how the
milk is thrown backwards
at five times the force of gravity,
and his mouth shuts like
a trap as it is swallowed.
It might be effective,
but it's far messier than the cat.
The two predators could
hardly be less alike,
but those brought up together
still find ways to communicate.
This cat scent-marks his
canine pal by rubbing him,
just as he would another cat.
But cats choose their
moments of affection,
and independence soon shows itself.
Cats are the only pet
that hunts independently,
and he's well equipped for the part.
Rat sounds are above our hearing,
but well within the cat's range.
And his superb night
vision pierces the gloom.
Sensory hairs on his paws test each
step, so as not to make a sound.
His gaze never leaves his prey.
Just like their wild counterparts,
housecats stalk as close as they can.
He freezes.
Any movement will trigger the attack.
Something has to give.
But this rat bites back!
Despite formidable senses, even wild
cats miss four times out of five.
Dogs rarely get to hunt, but
their senses are still razor sharp.
And they combine natural
skills with intelligence.
A well-fed dog looks for
somewhere to bury a bone,
just as he would in the wild.
But he's smart enough to
know he's being watched...
...and chooses somewhere out of sight.
Caching food is common among wolves
as they hedge their bets
against leaner times.
They remember their hideaways,
and return to them when hungry.
But dogs rarely retrieve
their buried treasures,
and this one won't ever get the chance!
In our world, the wild and
the domestic are so mixed up,
dogs often make some fundamental errors.
Burying bones, even in the wrong place,
is one of a dog's
favourite natural pastimes.
But carrying sticks
is even more popular.
In the wild, they bring
food back to their young,
and the instinct to
carry is still there.
Now, they even retrieve sticks
from water just for the fun of it.
Once out, human companions
need to move away fast.
In a single shake, he
can lose 70% of the water.
But he must rotate his body fast
enough to fling it from his fur.
Shaking starts at his head, but the
energy wave travels down his body.
His skin and fur whip the water
away as the shake changes direction.
The force at the hair tips can
reach 70 times that of gravity.
Small dogs must shake
faster than larger dogs
to achieve the same spin-dry result.
Stand nearby and
you're in for a soaking!
It's not just dogs that can make a mess.
Place a buck rabbit in a new cage,
and it's best to stand well back.
He makes himself at home by
spraying his scent everywhere.
He also scent-marks
with his cheek glands
and spreads his aroma by digging.
His actions make perfect sense
among wild-living rabbits.
On Rabbit Island in Japan,
feral pet rabbits live
a near-natural life
a whisker away from human visitors.
The same scent-marking
behaviour goes on here.
Any strange new objects
are immediately marked
so they become familiar.
Males spray females as they
compete with other males.
But, with so much competition,
it's every buck for himself.
Fights get quite heated
- they're not such cuddly bunnies now.
But the winners get the chance to mate.
Even though some need
time to get the hang of it!
After mating, the doe prepares the nest,
gathering bedding from wherever she can.
But, for the very best nest
lining, she needn't look far.
Nothing beats a blanket of fur.
Any pet given the
chance to live naturally
soon expresses their wild instincts.
Cats on this Japanese island
live a semi-wild existence,
but in higher numbers than
ever found in the wild.
A wild tomcat has just a
few females in his territory,
but here, cats are forced together
as they scavenge from fishermen.
They use their full
repertoire of catcalls
during the inevitable squabbles.
They make over 100 sounds
in all, some subtle -
some not so subtle!
As they scuffle over feeding rights,
young cats are at a disadvantage
and are often chased away.
Cats don't expect to share their food.
In nature they hunt alone,
and what they catch is theirs.
This kitten is allowed to push her
luck so she may be a young relative.
But cats seldom give up a meal.
Most look for a secluded
spot away from competitors,
but they're rarely left alone.
A hiss is universally understood,
but cats also know where
they are in the social order.
A kitten may hiss all he likes,
but in cat society, age comes first.
Cats also leave scent messages.
Males spray a pungent
note on key landmarks
to announce their presence.
They use other scent marks too.
Glands on the cheeks deposit
a unique personal odour.
They also mark those
they regard as friends -
just as pet cats rub scent
on the legs of human owners.
Scratching applies yet more
scent from glands on their feet.
But some cats prefer not
to announce their presence -
submissive cats bury
the smelly evidence,
just as they do in a litter tray.
In our homes, cats show
their subservience to us
by hiding their deposits.
Although few take it to this extreme!
This cat taught himself the technique.
If only he could learn
to pull the flush!
With no litter to cover his tracks,
he does what comes naturally -
make the scratching movements
that would normally bury his smell.
Whether scents are
concealed or openly flaunted,
most pets use odours to communicate.
But no-one uses smell
messaging quite like dogs.
In Cuzco, Peru, pet dogs are
allowed to roam the streets at will,
and can work out what every
other city dog is up to
using their noses.
Lampposts are irresistible for any dog,
but this scent-marking is
surprisingly sophisticated.
They act like notes
posted around the city,
and dogs deliberately save up their pee
to ensure there's enough to go round.
These messages show who they are
and, by the rate the smell decays,
how recently they've visited.
Dogs travelling together
over-mark each other's scent
to advertise the size of their pack.
It allows everyone to keep tabs on
the whereabouts of everyone else.
Dogs that spray higher are
more dominant and best avoided.
But plenty are immediately
recognised as friends.
In these playful encounters,
they associate the dogs they meet
with the scent marks
they've come across.
Besides scent, there are other ways
to find your mates in a big city.
A barking dog forces air through
his vocal cords at over 100mph.
The sound can exceed 110 decibels...
...louder than a passing jet.
Wolves rarely bark,
so this way of communicating
is a product of domestication.
And dogs produce a
complex variety of barks.
A rapid string of four to
five barks is a rallying call.
Hearing another dog bark increases
their heart rate, ready for action.
It doesn't take long for
the message to get around.
Once they find each other,
barking appears contagious.
One or two short, high-pitched
barks are used to greet a friend.
More continuous, lower-pitched
barks alert the pack to a stranger.
When the talking's over,
fights can break out.
It may look serious, but these
skirmishes are mostly for show
and rarely lead to bloodshed.
Their bark really is
worse than their bite.
We have only just begun to
decipher the dog's hidden messages.
But, using all their complex signals,
the dogs of Cuzco have created a
parallel world in a human city -
one known only to them.
Mutt or pampered pet,
street fighter or stray,
the dogs use their natural abilities
to sort out their differences
and find ways to get along.
They live in a secret
world of communication,
even though, at the end of the day,
most have human homes to return to.
Living together is all
about communication,
and for horses, herd life
would be impossible without it.
In the Camargue in France, the
behaviour of semi-wild horses
shows why they make such
perfect human companions.
A dominant mare leads a herd of
several females and their offspring.
This willingness to be led
is the reason a horse responds
so readily to our bidding.
The lead mare takes them
to a dust-bathing spot -
an important part of
their daily routine.
The leader rolls first.
As foals, they learnt
that there's a strict order
to even the simplest activity.
Prey animals always
need someone on watch.
The stallion's role is to protect
the herd, and he always rolls last.
The lead mare gains her position
through age and experience -
finding the best food and water is
one of her many responsibilities.
She continually communicates with
the herd, mostly using her ears.
They point towards a horse
she's trying to identify,
but she also uses the position of
her ears to convey her feelings.
16 muscles control each ear,
allowing subtle changes of expression.
If they're flopped down, it
means she's relaxed and happy.
When she's interested in
something, she pricks them forward.
And she pins them back
when she's annoyed.
If that doesn't produce the required
reaction, she follows with a charge.
Just pinning back the ears
is usually enough to
get the herd moving.
As well as responding to ear positions,
horses are very sensitive
to each other's touch,
and react to pressures too
light for humans to feel.
Riders tap into this sensitivity,
by a heel pressed against a side,
or minute changes of position.
Although horses communicate
in so many different ways,
it's friendship bonds that
lie at the heart of the herd.
And the very best friends
show their affection
by blowing in each other's noses.
Young stallions even practise
their fighting moves on a friend.
It's a chance to safely
try out techniques
that one day will be used in earnest.
But, for now, they're
the best of buddies.
Like all our animal companions,
horses possess
extraordinary wild abilities.
But all our pets are special
in their own unique way.
They find a way to live alongside
us, as part of the family,
but in a very different world.
Whether in play,
or through incredible senses,
they will always be wild at heart.