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(tigers growl)
Anyone fascinated by the natural world
has probably wondered why some animals
have such strange-looking sense organs.
(elephant growls)
The elephant with it's huge ears,
the antennae of a butterfly which up close
look like feathers.
The snake with it's split tongue
and what about less obvious enhancements,
like the sensory cells on a crocodile's skin?
Surely these evolutionary traits aren't just for decoration?
In fact, the size, shape and location
of these animal sense organs is all for a purpose
and just like us, animals rely on our senses to communicate
with each other, find their way around, stay safe
and most importantly to find food.
When you see how superior some animal senses are
compared to those of humans,
you might wonder how we ever stayed
on top of the food chain.
Animal super senses, you won't believe what's possible.
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When the sun sets, the animal kingdom swap shifts.
Day workers go to sleep while others get active.
This is the night shift and nocturnal animals
have taken to this dark world for good reason,
they escape from predators, avoid the heat of the day
and take their turn sharing food and resources
in their niche.
But to navigate life in the dark,
you need some special abilities to cope
with the lack of light.
In this episode of animal super senses,
we find out more about the animals that live in the shadows
and the adaptations they need to survive.
Eyes rely on light, so it may come as a surprise to learn
that some nocturnal animals depend on a great deal
of their sense of sight to operate in the darkness.
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Having large eyes, helps to compensate for low light levels.
The ring-tailed possum is an Australian marsupial
that spends the night feeding on leaves, flowers and bugs.
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They live life in the trees.
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An agile climber with claws on the hands and feet
including thumbs that help it to leap from branch to branch.
And a strong prehensile tail that acts like a fifth limb.
With large eyes, the possum has superb night vision.
Although, not a predator, the eyes face forward
providing binocular vision and depth perception,
useful for judging distances when jumping through the trees.
Gliders are a type of possum and like the ring-tailed,
they are forest dwellers.
But instead of climbing from tree to tree,
these possums do as their name suggests, glide.
A thin membrane attached between their ankle and wrist
helps them to fly.
Sugar gliders gnaw through bark of eucalyptus
and acacia trees to get the sap and gum underneath.
In spring and summer, they boost their diet with insects.
To search for food, they fling themselves from one trunk
to the next in the pitch black.
So, it helps a great deal for gliders
to have excellent night vision.
They are outfitted with huge, bulging eyes
but that's not all.
Experts think their widely spaced eyes
allow them to triangulate distance
and prepare them for gliding to the next food source.
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But the prize for the biggest eyes
to a strange-looking creature
that lives beyond Australia's northern boundaries.
Tarsiers are tiny primates found in the jungles
of southeast Asia.
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Their eyes are so large that one eyeball is bigger
than it's brain.
Foraging at night, large eyes help the retina
to collect more light.
Gremlin-like and entirely carnivorous,
they eat a variety of insects,
pouncing on them using powerful hind legs
from their treetop perches.
Long, spindly fingers help them cling to trees
and can be used as a kind of cage to trap prey
in the forest night.
Their forward facing saucer eyes
can't move in their sockets and take up half of their skull.
Because of this, thanks to specially adapted vertebrae,
Tarsiers have an owl-like ability
to turn their heads 180 degrees in each direction.
This gives them a very wild field of vision,
keeping an eye out for both prey and predators.
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The Tarsier has the biggest eyes in relation
to their body size of any mammal.
If human eyes were as big, they would be the size
of grapefruits.
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Tarsiers also have excellent hearing
with thin, mobile ears that can be unfurled
and retracted as needed.
They can easily pick up the sounds of scurrying insects.
It's gizmo's ability to detect and grab prey at night
using it's phenomenal senses
that is the key to it's success.
But unusually, they don't have one ability
that is common amongst nocturnal animals.
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When you look out into the darkness,
it can be somewhat alarming to see eyes glowing back at you.
The eerie twinkling is produced by nocturnal animals.
Cats eyes shine when caught in the glare
of a torch or a headlight, Tarsiers' eyes don't.
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There is a layer of reflective cells at the back
of the eye behind the retina known as the tapetum.
This layer bounces protons of light back
giving the eyes' sensory cells a second chance
at absorbing the rays.
Pigments in the retina reflect the color
of the reflected light.
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Not all nocturnal creatures have good eyesight.
Bilbies are desert dwelling marsupials
from Central Australia.
They avoid the heat of the day by being active at night.
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Also known as the rabbit-eared bandicoot,
as the name suggests, the bilby has huge outer ears,
all the better to hear with.
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They have a large pinnae, or external ear
that helps to funnel sound to the inner ear
and gives the bilby it's excellent sense of hearing.
The bilbies' big ears are hairless
and thought to be useful for regulating body temperature.
They're also flexible and can be rotated,
held flat against the body, stuck out
or even folded in half.
Bilbies aren't fussy when it comes to food.
Helped by a long pointy nose
with an excellent sense of smell.
They forage for subterranean insects, bulbs, seeds
and fungi by digging through the soil with powerful limbs
and foreclaws.
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It's thought they have such long ears
so that when bilbies are digging deep,
a portion of it remains above the ground
to keep an ear out for predators.
Perfectly adapted for arid conditions,
they don't drink water but get all the fluids they need
from food.
By the day, the bilby sleeps in deep, spiral burrows
which can dug two meters into the ground.
This protects them from the heat and daytime predators.
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In the arid Sonoran region of North America,
another desert dweller, the kangaroo rat
goes about it's nightly business eating grass seeds
and stuffing them into it's cheek pouches.
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This little hopper has specialized ears
but it's not the external part we see like the bilby
but the inside ear that's the key
to their supersized hearing.
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They have an enlarged eardrum and huge, air-filled chambers
in the middle ear.
This gives them acute sensitivity to sound,
especially those at lower frequencies.
This little rat may seem like it's had too much caffeine
but there's a good reason for it's bizarre behavior.
There's a hunter nearby with rat for dinner on it's mind.
Research has shown that the kangaroo rats' ears
are adapted to nocturnal life
allowing them to hear the low frequency sounds of predators
such as owls, windbeats or a rattlesnake's scales
rubbing against the ground.
The kangaroo rat senses danger and drums it's feet
on the ground and these low frequency sounds
warn it's offspring to be on alert.
But it also sends a message to the snake,
that it's presence has been detected
and that the odds of catching a meal are low.
The snake meanwhile, will continue
to wait for an opportune moment
and it uses every sense at it's disposal
to make sure that it will eventually eat.
After all, it's life depends on it.
Rattlesnakes, an iconic North American snake
known for it's characteristic rattle
found at the tip of it's tale.
(snake rattles)
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As night falls, a hungry rattler will move about
looking for a spot to ambush prey.
They use their heightened sense of smell to detect food
by flicking their tongues in and out.
This picks up scent particles and deposits them
on the Jacobson's organ,
a specialized chemical detecting structure
located in the roof of the mouth.
Rattlers are also known as pit vipers
because they have heat sensing organs
located in pits near their eyes.
This heat vision super sense is a useful tool for predators
that need to hunt prey in total darkness.
The pits allow them to see the heat signature of the prey.
The warmth given off by an animal
compared to it's cooler surroundings
which provides a heat image.
With an exceptional sense of smell
and super sense heat seeking vision,
it's little wonder the rattlesnake
is a formidable nocturnal hunter.
Down under, the rattlesnake may have competition
for the title of most affective nighttime killer.
The cat-sized tiger quoll is a meat-loving marsupial.
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This veracious hunter eat possums, bandicoots, reptiles
and birds, tracking them down
with it's superior sense of smell.
Like miniature bloodhounds, their movements are slow
and deliberate, with nose to the ground,
they follow the scent trails of their prey.
Once food is detected, they are quick to attack.
Razor sharp canines deliver the killing bite.
They're not fussy eaters and if they sniff an easy meal
like a dead wallaby laying around,
they will happily chow down.
But it's the quoll's sense of smell that may be even
more important to their survival.
It could actually save them from extinction.
In the top end of Australia, the northern quoll population
is in rapid decline.
An invasion of toxic king toads is the cause.
Northern quolls have a taste for the amphibian
but once eaten, they soon succumb to the poison
from the glands on the king toad's shoulders.
Researchers are putting them through quoll school
by feeding them sausages made of king toad legs
laced with a chemical to make the quolls feel sick
and it's working.
The quolls are turned off their deadly diet.
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In terms of antepodean nightmare animals,
the quoll keeps good company.
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Along with it's cat-like cousin, the Tasmanian devil
is also a member of the family of flesh-eating marsupials
only much bigger.
It is the largest of the carnivorous marsupials.
As aggressive, brawling beasts,
their ferocious behavior is legendary.
During the day, the devil rests in caves or hollow logs,
then comes out at night to find food.
Like the quolls, they have a well-developed sense of smell
but are rather clumsy when it comes
to actively pursuing prey.
They prefer to scavenge on the dead.
And it's at dinnertime,
they will often encounter other devils.
Jaw-wrestling, teeth-clashing, loud yowls and screams
are all common in territory disputes.
But a sense of touch is used here to minimize fighting.
Tasmanian devils have long whiskers,
not only in the usual whiskery places like the face
but also in clumps far back on the top of the head.
Their long whiskers help them forage in the dark.
They also help devils space themselves from each other
when gathering together at a carcass.
If devils whiskers are not touching each other
when they are feeding, they're safely outside
of biting range and with a bite force
among the highest recorded for any species,
that is something to avoid.
With such a super sense resume,
it's not the kind of creature you want to come across
on an evening stroll.
Following on the theme of Halloween frights,
another creature that haunts our nightmares, the bat.
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Vampire movies have a lot to answer for,
giving this little creature a bad reputation.
But microbats, like the
(indistinct) Mexican free-tailed bats eat insects not blood.
During the summer (indistinct) females
form maternity colonies where they give birth.
These groups can number hundreds of individuals
in what is known as a nursery roost.
For three to four weeks, the baby bats are fed solely
on their mother's milk.
Feeding young costs energy and research has shown
that lactating (indistinct)
make two foraging trips per night
to feed their growing young.
With a jerky, erratic flying style,
they pursue insects which they eat on the wing.
A single (indistinct) can consume up to 3,000 insects
in one night.
It's phenomenal prowess and aerial hunting
is thanks to a special super sense, echolocation.
Finding and catching small quick-moving insects
in the pitch black is not easy.
Vision is limited in low light,
so instead of using their eyes,
microbats see with sound.
They fire sound waves out into the darkness
and listen to echoes that come back.
Using echolocation,
the bat can determine where an insect is,
how far away it is and in what direction it is moving.
It's a technique humans use
to develop sonar navigation systems in the military
using expensive technology.
The little bat, of course, just does what comes naturally
with it's super sense.
The senses are the stars on animal super senses
and this episode has been no exception.
We've discovered animals use a range of sensory tools
to cope with life in the darkness.
Living the night shift doesn't stop nocturnal animals
using every sensory tactic in the book to survive.
So next time you're out there in the dark,
watch out for things that go bump in the night.
Join us next time on super senses to find out more
incredible powers of animal perception.
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