(dynamic music)
(tiger growling)
Anyone fascinated by the natural world
has probably wondered why some animals
have such strange looking sense origins.
The elephant with its huge ears.
The antennae of a butterfly,
which up close look like feathers.
The snake with its 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 animals' sense organs is all for a purpose.
And just like us, animals rely on their 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 managed
to stay on top of the food chain.
"Animal Super Senses,"
you won't believe what's possible.
(mysterious music)
(upbeat music) (birds calling)
Welcome to the show that puts you in the eyes and ears,
the taste buds and nerve endings of wild animals.
There's a whole world and more than one
spectrum of sensations that animals are aware of,
which just pass humans by.
And yet, while it's widely known that for example,
a dog's sense of smell is dozens of times
more acute than humans, or that goats have close to
a 360 degree field of vision.
(water rushing)
There is a kind of sixth sense that some animals have,
which still defies explanation.
Call it extra sensory perception.
Animal abilities we can't entirely explain,
but which leave us wondering and in awe.
(wind whooshing)
For example, take the animal response to disaster,
such as the tsunami.
Tragically, the tidal wave killed over 200,000 people,
but the animal population was comparatively unscathed.
Observers even recollect animals leaving
hours before the disaster.
How did they know?
Can animals' extra sensory powers predict natural disasters?
(ominous music)
Do animals have a kind of extra sensory perception,
or sixth sense that alerts them to danger?
(wolf howling)
Well, the answer is, we still really don't know.
But it's fascinating to speculate.
And that's mostly what we'll be doing
in this episode of "Animal Super Senses."
Asking questions.
(grass rustling)
The tsunami of 2004.
In the hours before the tsunami hit
there are reports that in elephant camps
the large mammals were becoming agitated.
They trumpeted loudly.
What may have been elephantine distress calls.
Many even managed to break free from their camps,
presumably to head for higher ground.
Just hours later, disaster.
(water rushing) (dynamic music)
(birds calling)
In retrospect, it seems entirely possible
the elephants were responding to low-frequency rumbles
that are produced when storms approach
and atmospheric weather changes occur.
These rumbles happen in a spectrum of sound
called infrasound, that is below our level of hearing.
But it is one which elephants use all the time
to communicate over long distances,
to listen in for approaching storms, and so on.
Infrasound can travel vast distances
through ground, air, and water.
It can be generated by wind and thunder,
volcanoes, earthquakes, and huge movements of water.
Scientists think that elephants feel these vibrations
through their trunks, or even their feet.
So the next time you see an elephant
with its trunk to the ground,
just think it may not be sniffing the terrain
but making a trunk call.
(dynamic music)
What that means, not just listening out for sound,
but picking up vibrations through its trunk,
which has been found contains a pressure sensitive nerve
capable of detecting seismic signals.
(plants rustling)
(thunder rumbling)
Meanwhile, you might think, wouldn't it be great
if humans had the ability to use infrasound
to detect natural phenomenon like hurricanes,
earthquakes, volcanic activity, and tsunamis.
Infrasound, low-frequency sounds, are produced by
a variety of geophysical processes,
but also some of the more traumatic man-made sources,
aircraft and explosions for example.
In the United States, the National Oceanic
and Atmospheric Administration, or NOAA,
are currently developing highly sophisticated instruments
to detect and monitor these kinds of extreme events.
Naturally, those kinds of instruments all cost
a small fortune to do what elephants do naturally,
without even making that big of a deal about it.
(rain dripping)
The production and perception of infrasound
has been observed in multiple mammals,
including whale, giraffe, hippo, and rhino.
We can assume that some animals are
influenced by environmental changes that can occur
before a natural calamity.
However, our understanding of such possible
precursor effects and how organisms react to them
is still very limited.
As long as this limitation exists,
the unusual behavior of animals alone
can not be used to evaluate an increased risk of earthquake,
or the arrival of a tsunami.
(waves crashing)
But there seem to be other cues which animals tune into
far beyond the reach of the normal sensory package.
If it's something in the air, then we're probably
going to be way, way down on the species list
before we sense it.
When it comes to noticing shifts in barometric pressure,
the sort of changes caused by
a hurricane at sea for instance,
it seems birds leave us for dust.
(water splashing)
Seagulls in particular, seem to know
when to seek shelter from the storm.
They instinctively head inland, away from the coastline,
prior to the onset of inclement weather.
It is believed they sense changes in the air pressure
and know just when it's time to hightail it out of there.
(funky music)
Some birds just seem to have an internal barometer
about these things, literally.
Migratory birds, for example,
like these white throated sparrows.
These fine-feathered fellas breed in Canada and New England.
But when the winter comes to call,
they migrate to warmer spots
in the Southern and Eastern United States.
(birds chirping)
Their in-built barometer, for thus it seems to be,
allows them to detect changes in air pressure.
Some birds' abilities to detect an approaching storm
can determine exactly when a large flock
leaves for a long flight.
Not only can they select the best departure time,
but also the best altitude for long-distance travel.
It's yet another instance where mankind
has to invent and design all kinds of sensitive
and expensive equipment just to match
what comes naturally in the wild.
(birds calling)
Some avian species act more like weather forecasters
than others do.
When humans lived closer to nature
several observations were made about birds and the weather.
Not all of them strictly scientific,
but seeming to contain more than a seed of truth.
Birds flying high in the sky are meant to be
a sign of fine weather approaching.
If they fly low however, or don't fly at all,
then it's believed a storm is on its way.
But then on the one hand,
some say birds become noisier as bad weather approaches.
While on the other, there are those who will swear
birds become abnormally quiet before a storm.
(gentle music)
Large groups of birds perching on power lines
is said to be an indication of stormy weather.
Another widely held belief is that
if birds feed during the rain,
it means the rain will last a long time.
If they don't come out to feed, then the rain will end soon.
(waves crashing)
The sixth sense for barometric pressure
certainly hasn't been distributed evenly
through the species.
We travel now with a certain amount of trepidation
to the shallow waters, coral reefs, and coastlines,
that is the natural habitat
of this sleek and deadly character.
(water whooshing)
It is the blacktip shark.
And it too has a similar uncanny ability to feel things.
But it is not so much in the air as in the water.
(dynamic music)
We all know that tropical storms develop
as low pressure systems offshore.
How do sharks respond to the pressure
of an approaching tropical storm?
There are some interesting facts that might surprise you.
In 2001, tropical storm Gabrielle
made landfall in central Florida.
Researchers had been tracking the movements
of a population of juvenile blacktip sharks
in a small bay there for about three years.
Blacktip sharks were typically residents
in this bay for six to eight months during the summer,
before swimming south for the winter.
The research corroborated that the blacktips
typically did not leave the area until migration time.
And definitely not in large groups.
As tropical storm Gabrielle approached the coast
the researchers simply didn't have enough time
to remove their array of acoustic receivers,
their listening stations, from the water.
They simply left them behind and hoped for the best.
(dramatic music)
Fortunately, the equipment was still intact after the storm.
And when researchers downloaded the data
a little while later, they discovered something amazing.
Not only had all the blacktip sharks
they had been tracking left, but as it turned out,
they had all split the scene
some seven hours before hurricane Gabrielle hit the coast.
The almost inescapable conclusion
was that the sharks responded to the decrease
in barometric air pressure that proceeds such a big storm
and made for the open seas.
(rain splashing)
(frogs calling)
When it comes to storm warnings, some of the evidence
for animal foresight is anecdotal at best,
and sometimes even a bit murky.
The most commonly repeated of these tales
is that of amphibians, namely frogs and toads.
Who are reputed to croak louder before rainfall.
Another fascinating case study is the tree frog,
where it is most commonly kept as a household pet.
(jaunty music)
Tree frog pets are most commonly kept in a big glass jar
with a ladder running up to the lid.
What the anecdotal evidence seems to suggest
is that if the tree frog stays at the bottom of the jar
then rain is eminent.
If, on the other hand, the little green chap
climbs up the ladder, then the higher he goes,
the better the weather will be.
Meanwhile, back in the wild, green tree frogs
are sometimes known as rain frogs.
They are so named because their call is said to be
the loudest at the onset of stormy weather.
(wind whooshing)
(dynamic music)
To find the most accurate weather forecasters on the planet
it's possible we need to get down on our knees
with a magnifying glass and look into the dirt.
Again, this observable phenomenon still doesn't exactly
come under the heading of scientific fact.
But could it be that ants
are the most reliable weather forecasters on Earth?
Any definitive conclusions will have to wait
until all the research is in.
But keen observers have noted
that when ants build steep mound sides to their nests
it seems to be an indication that rains are on their way.
With the approach of inclement weather,
ants have been witnessed carrying out
extra industrious labor, working furiously.
More furiously than usual to either build
and move into new nests,
or fix up and clean their existing nests.
Maybe it's only spring cleaning, but they also gather food
as if preparing for a siege,
the good little soldiers that they are.
But how do they know without being able to utilize
some type of extra sensory perception,
or insects' sixth sense?
Even the most accurate scientific research
still doesn't have a good answer for that.
(gentle music)
To observe another animal that has faculties
which could indicate a sixth sense,
you don't need a magnifying glass,
or indeed to travel to some exotic corner of the world.
In fact, you might not need to go
any further than your own backyard.
Long known as humans' best friend,
different breeds of dogs have demonstrated their loyalty
and courage throughout the centuries.
(dog panting)
They can also be trained as canine detectives,
able to sniff out everything from narcotics to termites,
concealed explosive devices,
to people trapped under rubble.
Smell is a dog's dominant sense, so much so
that a huge part of its brain is devoted to analyzing odors.
(water splashing)
Dogs have two giant olfactory bulbs attached to the brain,
which decode every smell they encounter.
The bulbs weigh about four times as much
as human olfactory bulbs.
But the source of the dog's exceptional ability
to smell is its wet snout.
The moist leathery surface of the snout
acts like Velcro, catching even
the tiniest molecules of smells, then dissolving them
so that the dog's internal smell receptor cells
can analyze them properly.
To keep his nose wet,
a dog must produce a constant supply of mucus
through its nasal cavities.
(upbeat music)
What is possibly less well-known is their seeming
extra sensory perception as medical detection dogs.
Medical detection dogs are becoming
increasingly popular among diabetics.
Dogs seem to have an uncanny ability
to alert their diabetic owners
when their blood sugar levels are too low.
Although odor clues seem to be
the most plausible explanation,
no one is entirely sure
how these adorable friends can do this.
(dramatic music)
The senses are the stars in super senses.
And this episode has been no exception.
We have been on a fantastic voyage
led by the extra sensory perceptions some animals have.
A few of which really do defy explanation.
The sixth senses have taken us
from the ocean depths to the jungle,
the teaming life underfoot,
to the migratory patterns of birds on the wing,
and the incredible sense of smell
of our inseparable canine friends.
And these super senses will be back
to fight again another day.
So join us next time on "Animal Super Senses."
(dynamic music)