Nova (1974–…): Season 41, Episode 9 - Inside Animal Minds: Dogs & Super Senses - full transcript
From PBS - What is it like to be a dog, a shark or a bird? This question is now getting serious attention from scientists who study animal senses. Humans rely on smell, sight, taste, touch and sound; other animals have super-powered versions of these senses, and a few have extra senses we don't have at all. From a dog that seems to use smell to tell time to a dolphin that can "see" with its ears, discover how animals use their senses in ways we humans can barely imagine. But it's not just the senses that are remarkable -- it's the brains that process them. NOVA goes into the minds of animals to "see" the world in an entirely new way.
What are they thinking?
Oh, look at that face!
Is there any way to get inside
the animal mind?
What I really want to know is
what is it like to be an animal,
what are the problems
they have to solve,
and how do they think,
and are they like us
or are they like something
totally different?
They have some amazing abilities
Is it instinct, training
or something else?
Cutting-edge animal science
opens a new window
on the roots
of animal intelligence
Explore their language,
relationships, even emotions
If you start giving
one of them grapes,
then the one who gets cucumber
becomes very upset
Are they more like us
than we ever thought possible?
Having a sense of self
would go with complex
understanding of others
In this episode,
who wins the battle
of the super senses?
They have hundreds of millions
more receptors
in their nose than a person does
But could a dog smell time?
5:00, he's there at the door
waiting for him
How do animals
experience the world?
There are animals that have
completely different senses
than we have
If would be close to impossible
to conceive
what that might be like
A new look "Inside Animal Minds:
Dogs and Super Senses,"
right now on NOVA.
What's going on inside
animal minds?
How can we even begin
to understand them,
what they know
and how they think?
If we're interested
in knowing anything
about what an animal
experiences,
I think we have to know
the kind of information
that they perceive,
and that's all about
their senses
I think our senses
are on the front line
of everything
we're doing mentally
But when it comes
to sensing the world,
all animals are not
created equal
We humans rely
on five primary senses
But some animals have the power
to perceive things
in ways we can't even imagine
Can we ever understand
how their super senses
shape their minds
and their behavior?
Scientists are trying to step
into the skin
and fur and feathers
of all kinds of creatures
to try to discover
how they sense their world
And they're finding
that some of the most impressive
powers of perception
can be found very close to home
As any dog owner knows,
this animal can be
a bit obsessed with smell
So for a dog, I think
you have to understand
that they are going
to experience the world
through their nose
The dog's entire experience
will be about sniffing
everything they encounter
in the world
But just how good is this nose?
The dog sense of smell
is much, much, much more acute
than the human sense of smell
To find out just how powerful
a dog's sense of smell can be,
we're putting a particular pooch
to the ultimate test
Neil Powell trains sniffer dogs,
and one of his top performers
is Fern
Today, she's going to try
to sniff out something
that's been hidden:
a canister containing meat
But here's the twist:
the canister is not hidden
in the woods
or even on dry land
It's at the bottom of this lake,
20 feet underwater
So this is an ultimate test
of the dog's scenting ability
It's probably as difficult
as it gets
Fern has been trained
to detect bodies
that have come to rest beneath
the surface of the water
Several hours ago,
a team dropped the meat
in the lake
and recorded its position
with GPS
Neil only knows roughly which
section of the lake it's in:
an area equal to about 30 acres
The question is,
can Fern find the exact spot?
The team's search technique
is to systematically
criss-cross the lake,
starting at the downwind end
Around ten minutes
after they start
to criss-cross the surface
Fern gives her signal
She's clearly
picked up the scent
But it takes over an hour
of going back and forth
to pinpoint the exact spot
where Fern indicates
it's the strongest
Bear her up into the wind, John
Right round, John
I'd put her there, John
Neil marks her choice
with a buoy
Now the team
that hid the canister moves in
to check it against the GPS
reading they took earlier
And amazingly,
Fern is within just a few feet
Fern was able to do this
because like all sniffer dogs,
she has a powerful
and well-trained nose
Oh, Fernie!
What a clever girl, Fernie!
Dogs' olfactory powers
are so potent,
they can be harnessed
to find all kinds of things
by sensing just a whiff
of drugs or guns or people
They hunt for victims
in disasters like earthquakes
and avalanches
All thanks to a nose
engineered to detect
the most minute traces
of a scent
A big secret of the dog's nose
is that it splits the flow
of incoming air
into separate streams,
with one fully dedicated
to smelling
The smelling tract is lined
with special tissues
densely packed with sensors
They have hundreds of millions
more receptors in their nose
than a person does,
and they have more elaborate
brain organs
to receive and comprehend
that olfactory information
Dogs can smell traces
of a substance
in parts per trillion
That's the equivalent
of being able to taste
a spoonful of sugar
dissolved in two Olympic size
swimming pools
Some experts believe that dogs
are so in tune
with the changing scent
of their environment
that they can smell things
we would never even realize
could have a smell
For example, is it possible
that a dog could smell time?
For humans, time is a concept
To keep track of it,
we depend on clocks
But could it be
that all a dog needs
to keep track of time
is its nose?
Meet the Threlkeld family:
Christine, Johnny, Faye, Mark
and Jazz, their Hungarian Viszla
They're convinced that Jazz
can tell time
because he knows exactly
when his master Johnny
is about to return home
at the end of the day
As soon as I drive in the drive,
I can see him at the window
As soon as I come in the door,
he's always at the door,
waiting for me to come home
And to witness this,
we left cameras running
all over their house for a week
The family have
a regular routine
Christine and Johnny
always leave the house
at the same time in the morning,
leaving Jazz to his own devices
And every afternoon, Christine
comes home at 4:00 p m
But it's what Jazz does next
that's intriguing
Every afternoon at around 4:40,
about 20 minutes
before Johnny comes home,
Jazz always leaps up
onto the sofa
as if he's waiting for him
He's like a canine alarm clock
Between half 4:00 and 5:00,
Jazz is always looking out
for Johnny
When Johnny comes in,
well, it's off that chair
right to the back door,
and by the time Johnny's there
at the door,
he's there waiting for him
It seems as if Jazz somehow
knows that Johnny's coming home
It's a claim made
by many dog owners
I think he's quite intelligent
So how does Jazz do it?
Now, it could just be that
Christine's coming home
sets Jazz's clock
We know it's not because
he needs dinner or a walk,
because Christine's
dealt with that
There's a theory that
a dog's sense of smell
could play a role
While Johnny is
out of the house,
the smell he leaves behind
gradually fades over the hours
So could it be that
when Johnny's scent drops
to a particular level,
Jazz senses he's
about to return?
Here, boy!
A story like that
makes perfect sense to me
I think it's possible that dogs
are in some way telling time
through the day
by odor concentrations
To test this theory,
at the end of the week,
Christine changes her routine
On her way home, she
swings by Johnny's soccer club
to get some freshly worn
t-shirts
And then when she gets back
at her usual time,
she wafts them around the living
room to spread Johnny's smell
If Jazz is using
the fading smell of Johnny
to sense the passage of time,
then this should be
the equivalent
of resetting the clock
So will Jazz know
what time it is?
It's now less than half an hour
before Johnny normally
comes home
But remarkably, Jazz
for the first time keeps dozing
It's now 4:48
Jazz only lifted his head
for about 30 seconds
He's lying flat out again,
enjoying the heat
of the radiator
Now Johnny's back, and to Jazz,
it seems to come
as a complete surprise
You coming over?
No?
He definitely wasn't
looking for him
It was as if he was
quite content
I think he didn't know
what the time was,
and I think the smell
of the clothes
that I had brought in
had obviously confused him
Now, this little experiment
with one dog
doesn't prove anything
There could be any number
of things Jazz is reacting to
But it's intriguing that dogs'
sense of smell might allow them
to grasp something
as abstract as time
So that to me is wonderful
because it really
shows that for dogs,
smell might give them
a sense of time,
which personally I can't
imagine in my head
with the types of smells
that I perceive
It turns out lots of animals
use their senses
and interact with the world
in ways profoundly
different from us,
especially if that world
is underwater
Dolphin senses are extremely
difficult to study in the wild,
but here at the Dolphin
Research Center in Florida,
scientists are investigating
the extraordinary
sensory talents
of a few dolphins
born in captivity
Like Tanner
Looking up, please
Attaboy!
Researcher Armando Rodriguez
has devised an experiment
to demonstrate Tanner's
abilities
Tanner has been trained
to mimic a swimmer's behavior,
and he's given
the command to imitate
with this hand signal
Today, the swimmer is Wade,
a dolphin trainer
Wade will perform
an action in the water
that Tanner has to copy
We ask the trainer in the water
to actually do that action,
and ask Tanner then to imitate
But it's not as simple
as it sounds,
because during the experiment,
Tanner will be blindfolded
The team is careful to make sure
Tanner has no idea
which action the trainer
will perform
We actually show the trainer
in the water the action
We don't want to say it
in case Tanner can get a cue
from that
Armando gives Tanner
the signal to imitate,
and then puts an eyecup
over his other eye
So can Tanner imitate
Wade's actions
despite being blindfolded?
Wade is upside down,
and Tanner is upside down, too
Wade spins, and Tanner spins
Good boy, excellent, Tanner
Give me five
Good man
And finally, the bob
Wade bobs up and down,
and Tanner does exactly
the same thing
Good!
You're running out, huh?
Very good
You know, I see this every day
and I still cannot get over
how extraordinary it is
that he does this
So how does Tanner do it?
Scientists believe
that although Tanner,
like all dolphins,
has pretty good vision,
he doesn't need his eyes
to see underwater
because he's able to sense his
surroundings in minute detail
thanks to the very special way
he uses his sense of hearing
Dolphins have no external ears,
but their inner ears provide
excellent hearing underwater,
and they put it to amazing use
in a process called echolocation
Here's how it works
The dolphin uses a special organ
behind the forehead
to emit focused pulses of sound,
or clicks
The sound waves from the clicks
bounce off other objects
in the water,
echoing back to the dolphin
Instead of external ears,
a cavity in the jaw
picks up and amplifies
those returning sound waves
before sending them on
to the inner ears
on either side
of the dolphin's head
Echolocation is very similar
to the sonar submarines use
In fact, it was scientists
in the Navy
wanting to improve their sonar
who first figured out
how dolphins do it
They attached small devices
to different parts
of the dolphin's head
These produced sounds
which the dolphin responded to
The strongest response
was measured
when the device was
on the dolphin's jaw
This is how scientists believe
Tanner can copy Wade
He is using echolocation
to essentially see Wade's body
and what he's doing in the water
To us, a dolphin's echoes
may sound like a cacophony
of random clicks
But listen to what happens
when we slow them down
This is a return echo
from an Atlantic cod,
while this is what's
bouncing back to the dolphin
from a different fish:
a mullet
The sound waves don't
simply tell the dolphin
about the outer form
of the fish;
they can reveal shapes
inside the fish as well
Some researchers believe
that dolphins
can tell different kinds
of fish apart
by reading the echoes bouncing
off their internal organs
It's probably one
of the most important,
if not the most important sense
for most dolphins
Echolocation has given dolphins
a clear evolutionary edge
If they're traveling at night,
they're going to need
the navigation
If they're traveling
in murky water,
they're going to need to be fed,
so to be able to detect a fish,
it's a wonderful thing to have
Lots of animals use one
of our five familiar senses
in completely unfamiliar ways
Starfish see, but not like we do
A basic light-sensitive eye
at the end of each arm
can form simple images,
helping them to find their way
around the sea floor
Butterflies and moths
have no nose,
but their sense of smell may be
even more sensitive than a dog's
because of their antennae,
fine-tuned to detect
just a few molecules of scent
For many creatures
throughout the animal kingdom,
the secret to their survival
has been the evolution
of super senses
And these aren't always simply
more powerful versions
of our five senses
Sometimes, animals
perceive things
that our bodies are
incapable of sensing
There are animals that have
completely different senses
than we have,
that it would be close
to impossible to conceive
of what that might be like
One of these animals
thrives here
off the island of Bimini
in the Bahamas:
the shark
Sharks are extremely
successful predators
They can smell tiny quantities
of blood over huge distances
and feel the miniscule
vibrations of prey in the water
But sharks have another sense
that we humans do not share
Researcher Eric Stroud
has devised an experiment
to demonstrate
with young lemon sharks
We've just captured
a juvenile lemon shark,
and to do an experiment
right now,
we need to turn it upside down,
and this is called
tonic immobility,
and after a few moments,
the shark will go
into a sleeplike state,
a comatose state
With the shark at rest,
Eric will test its sensitivity
to something a human would be
completely oblivious to:
a magnet
And this is perfect
to conduct an experiment
because right now,
nothing is bothering it,
so we're going
to introduce a magnet
and we're going to see
if the shark
can sense the magnetic field and
give us some type of response
But I don't want to cheat
I don't want the shark
to see it,
so we're going to put
a small blinder in here
so he can't see me coming,
and now I'm going to put
the magnet in the water
and approach the shark
That was a great response
What we had there was
a repellent response
The shark did not like
this magnetic field
Almost as if he'd had a powerful
light flashed in his eyes,
the shark was acutely sensitive
to Eric's magnet
As a control, Eric does the same
experiment with a piece of lead
And we don't get a response
So this proves it's not just
any piece of metal
that can interfere
with the shark's magnetic sense;
it really has to be
magnetic in nature
Sharks are clearly affected
by a magnetic field,
but they don't typically
encounter magnets
in their environment,
so why have they developed
this sense?
What we did in that experiment
is we induced a very strong
electromagnetic field
The movement of a magnet can
induce an electrical current
Magnets generate
a weak electrical field...
A flow of charge...
And so do the muscular
movements of prey,
including their beating hearts
When that animal is beating
or it's moving,
the muscles generate a very weak
electromagnetic field,
and that's what they're
gearing in on
They can locate the heartbeat
of, say, a crab or stingray
underneath the sand
It's another tool
in their predatory arsenal,
making it even harder
to hide from a shark
All thanks to an ingenious piece
of sensory anatomy
Sharks have organs called
the ampullae of Lorenzini,
which appear as dark openings
along the front of their noses
These are the ends of tiny tubes
filled with a jelly
The jelly can register
voltage differences
between the tube's opening
and its base
beneath the shark's skin
These are exquisitely sensitive,
able to pick up
billionths of a volt
So we've seen the effect
of a magnet on a young shark,
but could it have any effect
on a full-grown one?
Eric is heading out from Bimini
to Triangle Rocks,
a well-known gathering place
for large Caribbean reef sharks
He's joined by his colleague,
marine biologist Pat Rice
Together, they've come up
with a plan
to test a shark's magnetic sense
against one of their most
powerful instincts:
their urge to eat
We've just arrived
at the Triangle Rocks...
That's south
of South Bimini island...
And when we set up here,
six Caribbean
reef sharks arrived
These are adult sharks
and they vary between
maybe two to three meters
There's one big one down there
With the sharks gathered
around the boat,
Pat gets ready to dive in
This is probably
my hundredth dive
with these particular sharks,
and if you aren't
afraid of them,
they will stay away
from you, usually,
unless, you know, sometimes when
they get into a feeding frenzy,
all bets are off then
So here we have a Pelican case
full of magnets
See if I can get one off here
You can see
how powerful they are
Takes a Herculean task
to get them apart
These are barium ferrite,
ceramic magnets, very powerful,
so it's probably a good idea
to keep the cameras
away from them at least a meter
because anything that's magnetic
memory can be wiped clean,
so we don't want
to lose the shot
At the surface, Eric distracts
the sharks by feeding them
while Pat sets up the experiment
on the ocean floor
Right now, the key is to try to
keep the sharks near the surface
so that the divers can set up
the experiment down there
and the sharks are above them
25 feet below, Pat makes
two circles in the sand:
one with magnets
and one with bricks
He places the same
amount of bait
in the center of both of them
All the sharks up by the boat
will now be able
to smell the food
The question is,
will the magnets stop them
from eating the bait?
Here comes a shark,
and he ate right off the control
One shark bypasses the magnets
on the left
and goes straight into
the brick circle on the right
to take the bait
So will they take an interest
in the bait
inside the magnet circle
now that the brick circle
is empty?
Another animal moves in,
but before it can grab the bait,
it turns away
It seems to know
there's food there,
but it won't go
inside the ring of magnets
Jess, get more bait
Pat puts fresh bait
in the bricks
They're getting
a little feisty down here
But he's barely
had time to retreat
when a shark goes straight
for the brick circle again
We can't get it down fast enough
More bait, Andy!
The sharks grab the food
as soon as it's laid down
inside the bricks
Pat has replenished it
four times
They're pretty hungry today
But they don't touch the food...
a delicious fishtail...
Inside the magnets
Unlike this experiment,
in which the electric field
is overwhelmingly strong
and repels the sharks,
in the wild,
much weaker electric fields
produced by the moving muscles
of fish and other creatures
can actually attract them
We may never really
understand fully
how a shark is perceiving
the world around it,
and in this particular case,
because we don't have
an electric sense,
we have to kind of guess
Sea creatures have evolved
their own special ways
to perceive their watery worlds
to find prey
and help them navigate
What if your world
is not underwater
or on land,
but in the air?
Consider these birds
zipping around in the sky
They've got a lot to take in,
plus they need to migrate
hundreds of miles every year
Yet if they're going
to defy gravity,
they can't be weighed down
by a big brain
If you're a bird
and you need to fly,
you're going to have to have
a way to do it
so that your brain
doesn't weigh so much
that you can't get there
Birds on the wing can move
in any direction they choose
In some environments, there's a
constant risk of collision
What's more, predators
in the air, like hawks,
can attack from anywhere
So bird brains need
to take in information
from every direction
Many can see down, up,
left, right,
in front and behind,
all at the same time
And yet with nearly
300-degree vision,
a swallow can pull complex
maneuvers at 40 miles an hour
within inches of buildings
It's an incredible amount
of visual data to process,
all achieved with a tiny brain
A swallow's brain
weighs about one gram,
1,000 times lighter than ours
So how on earth do birds do it?
Clues might come from this
reconstruction of an experiment
based on research
originally conducted
at the University of Queensland
and Australian
National University
It involves some boards
with stripes painted on them
and a starling named Arnie
Are you ready?
We're going to get him to fly
down this corridor
And to begin with, we'll have
these stripes horizontal
and we'll time using
these precision timing gates
how long it takes him
Then we're going
to switch the boards
so that the stripes
are vertical,
and we'll see how that
changes things
To get a precise measurement
of Arnie's speed
as he flies down the corridor,
the starling must fly through
a light beam at the start
and at the finish
To make sure the results
are reliable
Yep, that worked
Arnie must complete at least
ten successful flights
Arnie's performing admirably
His flight times from one end
of the corridor to the other
are coming in
at less than two seconds
Yep, we've got ten
Now what we're going to do
is change the boards
and make them vertical
And we're going to try again
and see how that affects
the speed that the birds go at
With the stripe pattern changed,
the team repeats the experiment
That was the slowest time so far
Could the vertical stripes
really have slowed Arnie down?
Once we have a complete set
of flight times,
we can compare
how fast Arnie flew
through the vertical stripes
versus the horizontal
The average speed
for the horizontal stripes
was 16 5 feet per second
But for the vertical stripes,
it was only 15 3 feet per second
These results confirm
that the vertical stripes
slowed the bird down
by more than a foot per second
The reason why we see this
comes down to a neat trick
called optic flow
Optic flow is the way
animals' eyes sense motion,
and birds use it to help them
determine how fast to fly
When Arnie flies
through horizontal stripes,
the pattern changes very little
That pattern of information
is very smooth
and very continuous,
just as it would be
if the bird is flying
through an open environment
with objects way off
in the distance
But the vertical stripes create
an entirely different illusion
That's interpreted
as the bird being in a very
cluttered environment
with lots of objects,
like trees,
that it has to fly between
and navigate past
And so what it does is
it flies more slowly
When Arnie flies
through the vertical stripes,
the pattern changes constantly
His brain may be perceiving
the lines as nearby obstacles,
that makes him fly cautiously,
over a foot per second slower
The bird is able to make
these adjustments
based on minimal
visual information
Whether sharks or dolphins,
birds or butterflies,
all these animals make decisions
based on what their senses
tell them
And most of them, like us,
perceive the world
with multiple senses
So how do they put it
all together?
Evolution can design an organism
in a lot of different ways
in terms of how they listen
to their senses
And so you can see an organism
that is able to integrate
all their sensory input
at the same time
You can have another organism
that may prioritize
one sense over another
The way animals
prioritize their senses
can have a profound impact
on their behavior,
especially if those senses
seem to be delivering
conflicting information
So how do animals decide
which sense to trust the most?
Some intriguing research
is delving into that question
with our trusted companion,
the dog,
and comparing it
to its closest relative,
the wolf
Wolves are genetically
almost identical to dogs
The animals can even interbreed
But in the 10,000 years or more
since some were domesticated,
wolves haven't changed much
in appearance,
while dogs have been bred
to take on an astonishing
variety of shapes and sizes
But how different are dogs
and wolves inside their minds?
Do they use their senses
in the same way?
Here at Wolf Park in Indiana,
animal behaviorist Kathryn Lord
is trying to find out
She's studying a group
of ten wolves born in captivity
who now roam over a territory
of about 75 acres
Like most mammal predators,
wolves rely on their nose
to track down prey
Without it, they would starve
At Wolf Park, all the wolves
have been raised by humans
and have no need to hunt
for their supper
But they haven't lost their
acute appreciation of smelling
And as Kathryn has found,
they seem to have
some expensive taste
So I'm going to spray
this bottle of Channel No 5
over there
to see if we can't get
some scent rolling
So they come over here
and actually start pushing
their head and shoulder
into the ground
and rolling around in it
Dog owners might recognize
this kind of behavior,
but to scientists,
it's a bit of a mystery
Some think that wolves
developed this as a strategy
to carry interesting odors
back to their pack
We're not completely sure
why wolves
actually do this behavior
This particular perfume
as well as a number of perfumes
have a musk in them
which may be similar
to some pheromones
which are very important
to wolves
It may make them more attractive
to have the scent on them,
or they may just be trying
to show other wolves
that they've found
an interesting scent
We really don't know
Pheromones are natural chemicals
that can send signals
from one animal to another:
signals about fear or food
or finding a mate
Smell clearly plays a central
role in a wolf's life,
as it does for a dog
So dogs and wolves both have
an excellent sense of smell
They both seem to inhabit
the same sensory world
Let's go!
But as important as smell is,
are wolves and dogs slaves
to their noses?
As most dog owners know,
in addition to being
great sniffers,
these animals watch us
very closely with their eyes
and seem very interested
in what we do
So what role does vision play
in how dogs
understand the world?
Brian Hare has recruited dogs
from across the country
to test how they use
visual information,
particularly
when that information
is provided by a human
Okay, Sisu, stay!
One of the simplest examples
is the Pointing Test
And now watch
where her gaze goes,
right at me
Stay
All right,
so what we've got here
is a very simple experiment
We've got two people,
we've got two cups
We've hidden food in both cups
and we have a dog, of course
And all I'm going to do is
I'm going to gesture
to one of the two cups,
and the question is,
does the dog go where I gesture
or to the other cup?
Now, it can't be that
she's just using her smell
when she makes her decision
because there's food
in both cups
So let's see what she does
Both cups are hiding food
and smell equally appetizing,
so there's only one reason
for Sisu
to choose between them
Sisu, you ready?
The visual signal
Brian is giving her
Okay, Sisu
Good job
And there's one here, too
All right, so she did use
my gesture there
Sometimes I'll point
to the right
and sometimes I'll point
to the left
But let's do it again,
because it could be chance
Hey!
Okay, Sisu
All right!
So what we've seen is that Sisu
really relies
on my visual gestures
She's not relying on her nose
If I'm there
and tell her something,
she's much more happy
to use that information
than to rely on her nose
It's not too surprising
Okay!
Many dogs will eagerly follow
visual cues and gestures
given by humans, like pointing
Callie, is it there?
But we also know
they have great noses
So what happens when the two
senses... vision and smell...
Go head to head?
To find out,
Brian is going
to put Dexter's nose
in direct conflict
with Dexter's eyes
So we're going
to actually show Dexter
where we're going to hide
the food,
so he can remember
where he saw it
But then what we're going to do
is we're going to close his eyes
and then we're going to shift
where it's hidden
We're going to actually move it
to the other location
So that means he could
potentially smell where it is
The question is, does he use
what he saw to find the food
or does he rely on his nose?
So let's see what he does
All right, Dexter
Oh, look at that face
Oh, you're killing me
All right, Dexter,
are you ready, buddy?
Okay, that's where it's
going to be
This time, there's food
under only one cup
Okay, now close your eyes
And with Dexter's eyes covered,
Brian now moves the food
to the other cup
Poor Dexter's senses
are in direct conflict
Does he trust his eyes
or follow his nose?
Okay, Dexter, find it!
Aw, what happened?
It's a trick!
It's over here!
It was a trick!
Are you ready, Dexter?
Okay, we're going to put it
over here
Here it is
Close your eyes
Okay, Dexter, go get it!
Again and again,
Dexter, like most dogs,
goes not to where
he can smell the food,
but where he saw Brian
put the food
Aw
But what about wolves?
Will they pay attention
to visual cues from humans
in the same way?
Back at Wolf Park,
researchers are investigating
Hey, babies, hello
Kathryn Lord reared
this group of wolves from birth,
so unlike wolves born in the
wilderness, who avoid humans,
these can be quite friendly
Still, they are wild animals
and potentially dangerous,
and Kathryn knows to be careful
in their presence
If I was very hurt,
if I had a broken leg
or if I was very sick,
I probably wouldn't come in
just because I'd be
sending them signals
that might lead
to that sort of behavior
But otherwise, they're very
well socialized to humans,
so that's not usually
too much of a concern
Growing up with exposure
to humans
and receiving treats from them,
this grey wolf Fi responds
to certain types of information
that a wild wolf wouldn't
She comes when her name
is called
Fi!
And Fi can also follow
Kathryn's pointing
She seems to be just
as capable as a dog
of understanding what it means
But other tests
with dogs and wolves
reveal a dramatic difference
in their priorities
when it comes to paying
attention to people
When researchers
from Oregon State
gave wolves a closed container
with a tasty treat inside,
the animals focused intently
on getting the food out
But pet dogs,
given the same container,
tend to focus on their owners
Get it!
Only when the humans
actively encourage them
do the dogs really work
at getting the container open
So it's not that wolves
can't pay attention to humans,
but on a very fundamental level,
they don't need to
If they were students
in a classroom,
the wolf would be focusing
down on the test
and solving the problem
The dogs would be cheating by
looking at somebody else's test
So the dogs need us
to solve the problem
whereas the wolves
are perfectly capable
of doing it on their own
This is one of the key changes
that occurred in the wolf mind
when they were domesticated
and evolved into dogs:
they became extremely willing
to watch and pay attention to us
This may explain why
in some cases,
a dog will choose
to follow human gestures
instead of its own extremely
powerful nose
We're kind of suppressing
dogs' olfactory experience
We are in control,
for the most part,
of owned domestic dogs' lives
So how did this
transformation take place?
Kathryn believes this difference
between wolf and dog minds
may be closely linked
to how the animals
process sensory information
in the earliest weeks of life
Kathryn raised wolf pups
from a very young age
The wolf pups are great
So we get them at
about ten days of age
So at that point,
they can't see,
they can't hear
and they can't smell,
and they can't
really walk either
They're just kind of
little puddles of fur
You basically are a warm water
bottle that feeds them milk
So we bottle feed them
every four hours
It's very intensive,
you're with them 24/7
It's the only way
you can socialize them
There's a brief period of time
when baby animals
are open to new experiences
and become socialized
It's known
as the exploration window,
and it's a chance for them
to learn who and what is safe
while they're protected
from predators
Kathryn found that in wolves,
this window opens very early,
at two weeks,
when only the pups'
sense of smell is working
and they are still
blind and deaf
Over the next few weeks,
the pups start to see and hear,
but also gradually become
more fearful of new sensations
Dog puppies also have
an exploration window,
but it opens slightly later
The big difference is when they
start to explore their world
So dogs don't begin
to explore their world
until four weeks of age,
so that's two weeks later
than the wolves
And so when the dogs
start to explore their world,
they can already
see, hear and smell
But while the dogs have
all their senses powered up
when they're getting
to know their world,
wolves,
with fewer senses working,
will be exposed to far fewer
sensory experiences
before their fear of the
unfamiliar is firmly in place
Kathryn believes this is
one of the main reasons
wild wolves avoid humans
Even a well socialized wolf
is very different
from a well socialized dog
The wolves are more fearful
of novelty in general
than a dog is
Dog puppies can be exposed
to all sorts of sights,
smells and sounds
during their exploration window,
so when they're older,
more things will feel familiar
and they'll be more open
to new situations
This may help explain why dogs
can so easily form close
friendships with other animals,
whether human or not
The ability of dogs to be
flexible is what allowed them
to come into our environment
in the first place
and probably allowed them
to be domesticated
The early wolves
that evolved into dogs
were perhaps quite different
from the wolves of today
As pups, they may have had
a later window of exploration,
leaving them more open
to forming close relationships
with humans
For Kathryn, what might seem
a small difference in timing
during development
has had a profound impact
on how these two animals
use their senses,
and may be a key factor
in creating the dog mind,
comfortable around humans
and primed to become
a close companion
We're so close to our dogs
that some of us imagine
we can guess
what's on their minds
But for scientists,
it's a lot more complicated
One of the big questions,
of course,
that people have always
been interested in is,
do animals think at all?
And in asking that question
about animals,
it makes you think about
what is thought
and what drives
what we are thinking about
For decades, animal researchers
have relied on behavior
to try to determine
how animal minds work
But now things could be changing
because for the first time,
we may have a direct window
inside the animal mind
Neuroscientist Greg Berns
is adapting a medical technique
to study the activity
of brain cells in dogs
Okay, so stand by,
we're going to start the noise
MRI is a technique
that's been used in humans
for over 20 years
Normally, we use it
to study what the brain looks
like,
but with a few tricks,
we can actually do
what we call functional MRI,
which looks at brain activity,
and by analyzing the data,
we can figure out what parts
of the brain are doing what
But doing MRI on animals
is an entirely different game,
mainly because
of the requirement
that the subject has to hold
absolutely still
The need to keep still makes it
impossible to scan most animals
unless they're sedated,
which is not a good way
to study brains in action
One, two, three, steps!
But Greg has teamed up
with Mark Spivak to train dogs
for the unfamiliar conditions
they'll face
inside an MRI machine
One key requirement
is a steady supply of snacks
Well, a lot of humans
have difficulty taking MRI
First of all,
there's the enclosure,
which provokes anxiety
in many humans
Second, there's the absolute
motionlessness required
And then there's the noise
To block out the MRI noise,
the dogs are trained
to wear special ear covers
Without proper conditioning
and training,
the dogs would just run scared
from the MRI
Come here, girl!
Those that pass the test
graduate to the real thing,
like Kady
MRI is a noninvasive technique
at the very cutting edge
of animal science,
and it's beginning to reveal
fascinating insights
Patricia, we're going
to begin the first scan
with the localizer,
are you ready?
One of Greg's earliest
experiments
is revealing an important clue
as to what happens
in a dog's brain
when it receives information
from its senses
First, Kady is looking
at a visual signal
So Kady's in the scanner
right now
and Patricia's actually giving
Kady hand signals
So we've already taught the dogs
through lots of practice
that this means food, okay?
So every time Patricia
puts this signal up,
we're going to be looking
in her brain,
what that brain response is,
and we're actually going to be
looking at a very specific area
called the caudate nucleus
We also have another hand signal
that looks like this,
and that means no reward
After scanning many dogs,
Greg's results reveal
the area of the dog's brain
that responds
If we look very closely,
we find that the area
that's common to all the dogs
corresponds exactly to the same
part of the human brain
that responds to reward
Rewards like money, music, food,
all the things that humans like,
it's also activating
in the dog's brain
Even though Kady
isn't actually seeing food,
she can take a piece
of visual information
and interpret it to anticipate
that she will receive food,
and she's responding
emotionally, just like we do
This was pretty amazing
because it didn't have to be
that way
Dogs could be so different
from us,
they might have responded
completely differently,
but that doesn't seem
to be the case
And this reveals a complex chain
of brain activity
Ever since Pavlov,
people have viewed animals
as Pavlovian machines:
stimulus-response robots,
basically
And what we're finding is that
there's a tremendous amount
of processing
going on in their brains
that looks actually a lot like
what happens to humans
in exactly the same
circumstances
Dogs and probably most animals
have brains and minds
that are far more sophisticated
than we ever
gave them credit for
It's one of the great mysteries:
what are animals thinking?
Now, we are gaining
ever-greater insights
into their senses,
painting a clearer picture
of how the creatures around us
perceive their world,
whether it be dramatically
foreign to our own
or remarkably familiar
Oh, look at that face!
Is there any way to get inside
the animal mind?
What I really want to know is
what is it like to be an animal,
what are the problems
they have to solve,
and how do they think,
and are they like us
or are they like something
totally different?
They have some amazing abilities
Is it instinct, training
or something else?
Cutting-edge animal science
opens a new window
on the roots
of animal intelligence
Explore their language,
relationships, even emotions
If you start giving
one of them grapes,
then the one who gets cucumber
becomes very upset
Are they more like us
than we ever thought possible?
Having a sense of self
would go with complex
understanding of others
In this episode,
who wins the battle
of the super senses?
They have hundreds of millions
more receptors
in their nose than a person does
But could a dog smell time?
5:00, he's there at the door
waiting for him
How do animals
experience the world?
There are animals that have
completely different senses
than we have
If would be close to impossible
to conceive
what that might be like
A new look "Inside Animal Minds:
Dogs and Super Senses,"
right now on NOVA.
What's going on inside
animal minds?
How can we even begin
to understand them,
what they know
and how they think?
If we're interested
in knowing anything
about what an animal
experiences,
I think we have to know
the kind of information
that they perceive,
and that's all about
their senses
I think our senses
are on the front line
of everything
we're doing mentally
But when it comes
to sensing the world,
all animals are not
created equal
We humans rely
on five primary senses
But some animals have the power
to perceive things
in ways we can't even imagine
Can we ever understand
how their super senses
shape their minds
and their behavior?
Scientists are trying to step
into the skin
and fur and feathers
of all kinds of creatures
to try to discover
how they sense their world
And they're finding
that some of the most impressive
powers of perception
can be found very close to home
As any dog owner knows,
this animal can be
a bit obsessed with smell
So for a dog, I think
you have to understand
that they are going
to experience the world
through their nose
The dog's entire experience
will be about sniffing
everything they encounter
in the world
But just how good is this nose?
The dog sense of smell
is much, much, much more acute
than the human sense of smell
To find out just how powerful
a dog's sense of smell can be,
we're putting a particular pooch
to the ultimate test
Neil Powell trains sniffer dogs,
and one of his top performers
is Fern
Today, she's going to try
to sniff out something
that's been hidden:
a canister containing meat
But here's the twist:
the canister is not hidden
in the woods
or even on dry land
It's at the bottom of this lake,
20 feet underwater
So this is an ultimate test
of the dog's scenting ability
It's probably as difficult
as it gets
Fern has been trained
to detect bodies
that have come to rest beneath
the surface of the water
Several hours ago,
a team dropped the meat
in the lake
and recorded its position
with GPS
Neil only knows roughly which
section of the lake it's in:
an area equal to about 30 acres
The question is,
can Fern find the exact spot?
The team's search technique
is to systematically
criss-cross the lake,
starting at the downwind end
Around ten minutes
after they start
to criss-cross the surface
Fern gives her signal
She's clearly
picked up the scent
But it takes over an hour
of going back and forth
to pinpoint the exact spot
where Fern indicates
it's the strongest
Bear her up into the wind, John
Right round, John
I'd put her there, John
Neil marks her choice
with a buoy
Now the team
that hid the canister moves in
to check it against the GPS
reading they took earlier
And amazingly,
Fern is within just a few feet
Fern was able to do this
because like all sniffer dogs,
she has a powerful
and well-trained nose
Oh, Fernie!
What a clever girl, Fernie!
Dogs' olfactory powers
are so potent,
they can be harnessed
to find all kinds of things
by sensing just a whiff
of drugs or guns or people
They hunt for victims
in disasters like earthquakes
and avalanches
All thanks to a nose
engineered to detect
the most minute traces
of a scent
A big secret of the dog's nose
is that it splits the flow
of incoming air
into separate streams,
with one fully dedicated
to smelling
The smelling tract is lined
with special tissues
densely packed with sensors
They have hundreds of millions
more receptors in their nose
than a person does,
and they have more elaborate
brain organs
to receive and comprehend
that olfactory information
Dogs can smell traces
of a substance
in parts per trillion
That's the equivalent
of being able to taste
a spoonful of sugar
dissolved in two Olympic size
swimming pools
Some experts believe that dogs
are so in tune
with the changing scent
of their environment
that they can smell things
we would never even realize
could have a smell
For example, is it possible
that a dog could smell time?
For humans, time is a concept
To keep track of it,
we depend on clocks
But could it be
that all a dog needs
to keep track of time
is its nose?
Meet the Threlkeld family:
Christine, Johnny, Faye, Mark
and Jazz, their Hungarian Viszla
They're convinced that Jazz
can tell time
because he knows exactly
when his master Johnny
is about to return home
at the end of the day
As soon as I drive in the drive,
I can see him at the window
As soon as I come in the door,
he's always at the door,
waiting for me to come home
And to witness this,
we left cameras running
all over their house for a week
The family have
a regular routine
Christine and Johnny
always leave the house
at the same time in the morning,
leaving Jazz to his own devices
And every afternoon, Christine
comes home at 4:00 p m
But it's what Jazz does next
that's intriguing
Every afternoon at around 4:40,
about 20 minutes
before Johnny comes home,
Jazz always leaps up
onto the sofa
as if he's waiting for him
He's like a canine alarm clock
Between half 4:00 and 5:00,
Jazz is always looking out
for Johnny
When Johnny comes in,
well, it's off that chair
right to the back door,
and by the time Johnny's there
at the door,
he's there waiting for him
It seems as if Jazz somehow
knows that Johnny's coming home
It's a claim made
by many dog owners
I think he's quite intelligent
So how does Jazz do it?
Now, it could just be that
Christine's coming home
sets Jazz's clock
We know it's not because
he needs dinner or a walk,
because Christine's
dealt with that
There's a theory that
a dog's sense of smell
could play a role
While Johnny is
out of the house,
the smell he leaves behind
gradually fades over the hours
So could it be that
when Johnny's scent drops
to a particular level,
Jazz senses he's
about to return?
Here, boy!
A story like that
makes perfect sense to me
I think it's possible that dogs
are in some way telling time
through the day
by odor concentrations
To test this theory,
at the end of the week,
Christine changes her routine
On her way home, she
swings by Johnny's soccer club
to get some freshly worn
t-shirts
And then when she gets back
at her usual time,
she wafts them around the living
room to spread Johnny's smell
If Jazz is using
the fading smell of Johnny
to sense the passage of time,
then this should be
the equivalent
of resetting the clock
So will Jazz know
what time it is?
It's now less than half an hour
before Johnny normally
comes home
But remarkably, Jazz
for the first time keeps dozing
It's now 4:48
Jazz only lifted his head
for about 30 seconds
He's lying flat out again,
enjoying the heat
of the radiator
Now Johnny's back, and to Jazz,
it seems to come
as a complete surprise
You coming over?
No?
He definitely wasn't
looking for him
It was as if he was
quite content
I think he didn't know
what the time was,
and I think the smell
of the clothes
that I had brought in
had obviously confused him
Now, this little experiment
with one dog
doesn't prove anything
There could be any number
of things Jazz is reacting to
But it's intriguing that dogs'
sense of smell might allow them
to grasp something
as abstract as time
So that to me is wonderful
because it really
shows that for dogs,
smell might give them
a sense of time,
which personally I can't
imagine in my head
with the types of smells
that I perceive
It turns out lots of animals
use their senses
and interact with the world
in ways profoundly
different from us,
especially if that world
is underwater
Dolphin senses are extremely
difficult to study in the wild,
but here at the Dolphin
Research Center in Florida,
scientists are investigating
the extraordinary
sensory talents
of a few dolphins
born in captivity
Like Tanner
Looking up, please
Attaboy!
Researcher Armando Rodriguez
has devised an experiment
to demonstrate Tanner's
abilities
Tanner has been trained
to mimic a swimmer's behavior,
and he's given
the command to imitate
with this hand signal
Today, the swimmer is Wade,
a dolphin trainer
Wade will perform
an action in the water
that Tanner has to copy
We ask the trainer in the water
to actually do that action,
and ask Tanner then to imitate
But it's not as simple
as it sounds,
because during the experiment,
Tanner will be blindfolded
The team is careful to make sure
Tanner has no idea
which action the trainer
will perform
We actually show the trainer
in the water the action
We don't want to say it
in case Tanner can get a cue
from that
Armando gives Tanner
the signal to imitate,
and then puts an eyecup
over his other eye
So can Tanner imitate
Wade's actions
despite being blindfolded?
Wade is upside down,
and Tanner is upside down, too
Wade spins, and Tanner spins
Good boy, excellent, Tanner
Give me five
Good man
And finally, the bob
Wade bobs up and down,
and Tanner does exactly
the same thing
Good!
You're running out, huh?
Very good
You know, I see this every day
and I still cannot get over
how extraordinary it is
that he does this
So how does Tanner do it?
Scientists believe
that although Tanner,
like all dolphins,
has pretty good vision,
he doesn't need his eyes
to see underwater
because he's able to sense his
surroundings in minute detail
thanks to the very special way
he uses his sense of hearing
Dolphins have no external ears,
but their inner ears provide
excellent hearing underwater,
and they put it to amazing use
in a process called echolocation
Here's how it works
The dolphin uses a special organ
behind the forehead
to emit focused pulses of sound,
or clicks
The sound waves from the clicks
bounce off other objects
in the water,
echoing back to the dolphin
Instead of external ears,
a cavity in the jaw
picks up and amplifies
those returning sound waves
before sending them on
to the inner ears
on either side
of the dolphin's head
Echolocation is very similar
to the sonar submarines use
In fact, it was scientists
in the Navy
wanting to improve their sonar
who first figured out
how dolphins do it
They attached small devices
to different parts
of the dolphin's head
These produced sounds
which the dolphin responded to
The strongest response
was measured
when the device was
on the dolphin's jaw
This is how scientists believe
Tanner can copy Wade
He is using echolocation
to essentially see Wade's body
and what he's doing in the water
To us, a dolphin's echoes
may sound like a cacophony
of random clicks
But listen to what happens
when we slow them down
This is a return echo
from an Atlantic cod,
while this is what's
bouncing back to the dolphin
from a different fish:
a mullet
The sound waves don't
simply tell the dolphin
about the outer form
of the fish;
they can reveal shapes
inside the fish as well
Some researchers believe
that dolphins
can tell different kinds
of fish apart
by reading the echoes bouncing
off their internal organs
It's probably one
of the most important,
if not the most important sense
for most dolphins
Echolocation has given dolphins
a clear evolutionary edge
If they're traveling at night,
they're going to need
the navigation
If they're traveling
in murky water,
they're going to need to be fed,
so to be able to detect a fish,
it's a wonderful thing to have
Lots of animals use one
of our five familiar senses
in completely unfamiliar ways
Starfish see, but not like we do
A basic light-sensitive eye
at the end of each arm
can form simple images,
helping them to find their way
around the sea floor
Butterflies and moths
have no nose,
but their sense of smell may be
even more sensitive than a dog's
because of their antennae,
fine-tuned to detect
just a few molecules of scent
For many creatures
throughout the animal kingdom,
the secret to their survival
has been the evolution
of super senses
And these aren't always simply
more powerful versions
of our five senses
Sometimes, animals
perceive things
that our bodies are
incapable of sensing
There are animals that have
completely different senses
than we have,
that it would be close
to impossible to conceive
of what that might be like
One of these animals
thrives here
off the island of Bimini
in the Bahamas:
the shark
Sharks are extremely
successful predators
They can smell tiny quantities
of blood over huge distances
and feel the miniscule
vibrations of prey in the water
But sharks have another sense
that we humans do not share
Researcher Eric Stroud
has devised an experiment
to demonstrate
with young lemon sharks
We've just captured
a juvenile lemon shark,
and to do an experiment
right now,
we need to turn it upside down,
and this is called
tonic immobility,
and after a few moments,
the shark will go
into a sleeplike state,
a comatose state
With the shark at rest,
Eric will test its sensitivity
to something a human would be
completely oblivious to:
a magnet
And this is perfect
to conduct an experiment
because right now,
nothing is bothering it,
so we're going
to introduce a magnet
and we're going to see
if the shark
can sense the magnetic field and
give us some type of response
But I don't want to cheat
I don't want the shark
to see it,
so we're going to put
a small blinder in here
so he can't see me coming,
and now I'm going to put
the magnet in the water
and approach the shark
That was a great response
What we had there was
a repellent response
The shark did not like
this magnetic field
Almost as if he'd had a powerful
light flashed in his eyes,
the shark was acutely sensitive
to Eric's magnet
As a control, Eric does the same
experiment with a piece of lead
And we don't get a response
So this proves it's not just
any piece of metal
that can interfere
with the shark's magnetic sense;
it really has to be
magnetic in nature
Sharks are clearly affected
by a magnetic field,
but they don't typically
encounter magnets
in their environment,
so why have they developed
this sense?
What we did in that experiment
is we induced a very strong
electromagnetic field
The movement of a magnet can
induce an electrical current
Magnets generate
a weak electrical field...
A flow of charge...
And so do the muscular
movements of prey,
including their beating hearts
When that animal is beating
or it's moving,
the muscles generate a very weak
electromagnetic field,
and that's what they're
gearing in on
They can locate the heartbeat
of, say, a crab or stingray
underneath the sand
It's another tool
in their predatory arsenal,
making it even harder
to hide from a shark
All thanks to an ingenious piece
of sensory anatomy
Sharks have organs called
the ampullae of Lorenzini,
which appear as dark openings
along the front of their noses
These are the ends of tiny tubes
filled with a jelly
The jelly can register
voltage differences
between the tube's opening
and its base
beneath the shark's skin
These are exquisitely sensitive,
able to pick up
billionths of a volt
So we've seen the effect
of a magnet on a young shark,
but could it have any effect
on a full-grown one?
Eric is heading out from Bimini
to Triangle Rocks,
a well-known gathering place
for large Caribbean reef sharks
He's joined by his colleague,
marine biologist Pat Rice
Together, they've come up
with a plan
to test a shark's magnetic sense
against one of their most
powerful instincts:
their urge to eat
We've just arrived
at the Triangle Rocks...
That's south
of South Bimini island...
And when we set up here,
six Caribbean
reef sharks arrived
These are adult sharks
and they vary between
maybe two to three meters
There's one big one down there
With the sharks gathered
around the boat,
Pat gets ready to dive in
This is probably
my hundredth dive
with these particular sharks,
and if you aren't
afraid of them,
they will stay away
from you, usually,
unless, you know, sometimes when
they get into a feeding frenzy,
all bets are off then
So here we have a Pelican case
full of magnets
See if I can get one off here
You can see
how powerful they are
Takes a Herculean task
to get them apart
These are barium ferrite,
ceramic magnets, very powerful,
so it's probably a good idea
to keep the cameras
away from them at least a meter
because anything that's magnetic
memory can be wiped clean,
so we don't want
to lose the shot
At the surface, Eric distracts
the sharks by feeding them
while Pat sets up the experiment
on the ocean floor
Right now, the key is to try to
keep the sharks near the surface
so that the divers can set up
the experiment down there
and the sharks are above them
25 feet below, Pat makes
two circles in the sand:
one with magnets
and one with bricks
He places the same
amount of bait
in the center of both of them
All the sharks up by the boat
will now be able
to smell the food
The question is,
will the magnets stop them
from eating the bait?
Here comes a shark,
and he ate right off the control
One shark bypasses the magnets
on the left
and goes straight into
the brick circle on the right
to take the bait
So will they take an interest
in the bait
inside the magnet circle
now that the brick circle
is empty?
Another animal moves in,
but before it can grab the bait,
it turns away
It seems to know
there's food there,
but it won't go
inside the ring of magnets
Jess, get more bait
Pat puts fresh bait
in the bricks
They're getting
a little feisty down here
But he's barely
had time to retreat
when a shark goes straight
for the brick circle again
We can't get it down fast enough
More bait, Andy!
The sharks grab the food
as soon as it's laid down
inside the bricks
Pat has replenished it
four times
They're pretty hungry today
But they don't touch the food...
a delicious fishtail...
Inside the magnets
Unlike this experiment,
in which the electric field
is overwhelmingly strong
and repels the sharks,
in the wild,
much weaker electric fields
produced by the moving muscles
of fish and other creatures
can actually attract them
We may never really
understand fully
how a shark is perceiving
the world around it,
and in this particular case,
because we don't have
an electric sense,
we have to kind of guess
Sea creatures have evolved
their own special ways
to perceive their watery worlds
to find prey
and help them navigate
What if your world
is not underwater
or on land,
but in the air?
Consider these birds
zipping around in the sky
They've got a lot to take in,
plus they need to migrate
hundreds of miles every year
Yet if they're going
to defy gravity,
they can't be weighed down
by a big brain
If you're a bird
and you need to fly,
you're going to have to have
a way to do it
so that your brain
doesn't weigh so much
that you can't get there
Birds on the wing can move
in any direction they choose
In some environments, there's a
constant risk of collision
What's more, predators
in the air, like hawks,
can attack from anywhere
So bird brains need
to take in information
from every direction
Many can see down, up,
left, right,
in front and behind,
all at the same time
And yet with nearly
300-degree vision,
a swallow can pull complex
maneuvers at 40 miles an hour
within inches of buildings
It's an incredible amount
of visual data to process,
all achieved with a tiny brain
A swallow's brain
weighs about one gram,
1,000 times lighter than ours
So how on earth do birds do it?
Clues might come from this
reconstruction of an experiment
based on research
originally conducted
at the University of Queensland
and Australian
National University
It involves some boards
with stripes painted on them
and a starling named Arnie
Are you ready?
We're going to get him to fly
down this corridor
And to begin with, we'll have
these stripes horizontal
and we'll time using
these precision timing gates
how long it takes him
Then we're going
to switch the boards
so that the stripes
are vertical,
and we'll see how that
changes things
To get a precise measurement
of Arnie's speed
as he flies down the corridor,
the starling must fly through
a light beam at the start
and at the finish
To make sure the results
are reliable
Yep, that worked
Arnie must complete at least
ten successful flights
Arnie's performing admirably
His flight times from one end
of the corridor to the other
are coming in
at less than two seconds
Yep, we've got ten
Now what we're going to do
is change the boards
and make them vertical
And we're going to try again
and see how that affects
the speed that the birds go at
With the stripe pattern changed,
the team repeats the experiment
That was the slowest time so far
Could the vertical stripes
really have slowed Arnie down?
Once we have a complete set
of flight times,
we can compare
how fast Arnie flew
through the vertical stripes
versus the horizontal
The average speed
for the horizontal stripes
was 16 5 feet per second
But for the vertical stripes,
it was only 15 3 feet per second
These results confirm
that the vertical stripes
slowed the bird down
by more than a foot per second
The reason why we see this
comes down to a neat trick
called optic flow
Optic flow is the way
animals' eyes sense motion,
and birds use it to help them
determine how fast to fly
When Arnie flies
through horizontal stripes,
the pattern changes very little
That pattern of information
is very smooth
and very continuous,
just as it would be
if the bird is flying
through an open environment
with objects way off
in the distance
But the vertical stripes create
an entirely different illusion
That's interpreted
as the bird being in a very
cluttered environment
with lots of objects,
like trees,
that it has to fly between
and navigate past
And so what it does is
it flies more slowly
When Arnie flies
through the vertical stripes,
the pattern changes constantly
His brain may be perceiving
the lines as nearby obstacles,
that makes him fly cautiously,
over a foot per second slower
The bird is able to make
these adjustments
based on minimal
visual information
Whether sharks or dolphins,
birds or butterflies,
all these animals make decisions
based on what their senses
tell them
And most of them, like us,
perceive the world
with multiple senses
So how do they put it
all together?
Evolution can design an organism
in a lot of different ways
in terms of how they listen
to their senses
And so you can see an organism
that is able to integrate
all their sensory input
at the same time
You can have another organism
that may prioritize
one sense over another
The way animals
prioritize their senses
can have a profound impact
on their behavior,
especially if those senses
seem to be delivering
conflicting information
So how do animals decide
which sense to trust the most?
Some intriguing research
is delving into that question
with our trusted companion,
the dog,
and comparing it
to its closest relative,
the wolf
Wolves are genetically
almost identical to dogs
The animals can even interbreed
But in the 10,000 years or more
since some were domesticated,
wolves haven't changed much
in appearance,
while dogs have been bred
to take on an astonishing
variety of shapes and sizes
But how different are dogs
and wolves inside their minds?
Do they use their senses
in the same way?
Here at Wolf Park in Indiana,
animal behaviorist Kathryn Lord
is trying to find out
She's studying a group
of ten wolves born in captivity
who now roam over a territory
of about 75 acres
Like most mammal predators,
wolves rely on their nose
to track down prey
Without it, they would starve
At Wolf Park, all the wolves
have been raised by humans
and have no need to hunt
for their supper
But they haven't lost their
acute appreciation of smelling
And as Kathryn has found,
they seem to have
some expensive taste
So I'm going to spray
this bottle of Channel No 5
over there
to see if we can't get
some scent rolling
So they come over here
and actually start pushing
their head and shoulder
into the ground
and rolling around in it
Dog owners might recognize
this kind of behavior,
but to scientists,
it's a bit of a mystery
Some think that wolves
developed this as a strategy
to carry interesting odors
back to their pack
We're not completely sure
why wolves
actually do this behavior
This particular perfume
as well as a number of perfumes
have a musk in them
which may be similar
to some pheromones
which are very important
to wolves
It may make them more attractive
to have the scent on them,
or they may just be trying
to show other wolves
that they've found
an interesting scent
We really don't know
Pheromones are natural chemicals
that can send signals
from one animal to another:
signals about fear or food
or finding a mate
Smell clearly plays a central
role in a wolf's life,
as it does for a dog
So dogs and wolves both have
an excellent sense of smell
They both seem to inhabit
the same sensory world
Let's go!
But as important as smell is,
are wolves and dogs slaves
to their noses?
As most dog owners know,
in addition to being
great sniffers,
these animals watch us
very closely with their eyes
and seem very interested
in what we do
So what role does vision play
in how dogs
understand the world?
Brian Hare has recruited dogs
from across the country
to test how they use
visual information,
particularly
when that information
is provided by a human
Okay, Sisu, stay!
One of the simplest examples
is the Pointing Test
And now watch
where her gaze goes,
right at me
Stay
All right,
so what we've got here
is a very simple experiment
We've got two people,
we've got two cups
We've hidden food in both cups
and we have a dog, of course
And all I'm going to do is
I'm going to gesture
to one of the two cups,
and the question is,
does the dog go where I gesture
or to the other cup?
Now, it can't be that
she's just using her smell
when she makes her decision
because there's food
in both cups
So let's see what she does
Both cups are hiding food
and smell equally appetizing,
so there's only one reason
for Sisu
to choose between them
Sisu, you ready?
The visual signal
Brian is giving her
Okay, Sisu
Good job
And there's one here, too
All right, so she did use
my gesture there
Sometimes I'll point
to the right
and sometimes I'll point
to the left
But let's do it again,
because it could be chance
Hey!
Okay, Sisu
All right!
So what we've seen is that Sisu
really relies
on my visual gestures
She's not relying on her nose
If I'm there
and tell her something,
she's much more happy
to use that information
than to rely on her nose
It's not too surprising
Okay!
Many dogs will eagerly follow
visual cues and gestures
given by humans, like pointing
Callie, is it there?
But we also know
they have great noses
So what happens when the two
senses... vision and smell...
Go head to head?
To find out,
Brian is going
to put Dexter's nose
in direct conflict
with Dexter's eyes
So we're going
to actually show Dexter
where we're going to hide
the food,
so he can remember
where he saw it
But then what we're going to do
is we're going to close his eyes
and then we're going to shift
where it's hidden
We're going to actually move it
to the other location
So that means he could
potentially smell where it is
The question is, does he use
what he saw to find the food
or does he rely on his nose?
So let's see what he does
All right, Dexter
Oh, look at that face
Oh, you're killing me
All right, Dexter,
are you ready, buddy?
Okay, that's where it's
going to be
This time, there's food
under only one cup
Okay, now close your eyes
And with Dexter's eyes covered,
Brian now moves the food
to the other cup
Poor Dexter's senses
are in direct conflict
Does he trust his eyes
or follow his nose?
Okay, Dexter, find it!
Aw, what happened?
It's a trick!
It's over here!
It was a trick!
Are you ready, Dexter?
Okay, we're going to put it
over here
Here it is
Close your eyes
Okay, Dexter, go get it!
Again and again,
Dexter, like most dogs,
goes not to where
he can smell the food,
but where he saw Brian
put the food
Aw
But what about wolves?
Will they pay attention
to visual cues from humans
in the same way?
Back at Wolf Park,
researchers are investigating
Hey, babies, hello
Kathryn Lord reared
this group of wolves from birth,
so unlike wolves born in the
wilderness, who avoid humans,
these can be quite friendly
Still, they are wild animals
and potentially dangerous,
and Kathryn knows to be careful
in their presence
If I was very hurt,
if I had a broken leg
or if I was very sick,
I probably wouldn't come in
just because I'd be
sending them signals
that might lead
to that sort of behavior
But otherwise, they're very
well socialized to humans,
so that's not usually
too much of a concern
Growing up with exposure
to humans
and receiving treats from them,
this grey wolf Fi responds
to certain types of information
that a wild wolf wouldn't
She comes when her name
is called
Fi!
And Fi can also follow
Kathryn's pointing
She seems to be just
as capable as a dog
of understanding what it means
But other tests
with dogs and wolves
reveal a dramatic difference
in their priorities
when it comes to paying
attention to people
When researchers
from Oregon State
gave wolves a closed container
with a tasty treat inside,
the animals focused intently
on getting the food out
But pet dogs,
given the same container,
tend to focus on their owners
Get it!
Only when the humans
actively encourage them
do the dogs really work
at getting the container open
So it's not that wolves
can't pay attention to humans,
but on a very fundamental level,
they don't need to
If they were students
in a classroom,
the wolf would be focusing
down on the test
and solving the problem
The dogs would be cheating by
looking at somebody else's test
So the dogs need us
to solve the problem
whereas the wolves
are perfectly capable
of doing it on their own
This is one of the key changes
that occurred in the wolf mind
when they were domesticated
and evolved into dogs:
they became extremely willing
to watch and pay attention to us
This may explain why
in some cases,
a dog will choose
to follow human gestures
instead of its own extremely
powerful nose
We're kind of suppressing
dogs' olfactory experience
We are in control,
for the most part,
of owned domestic dogs' lives
So how did this
transformation take place?
Kathryn believes this difference
between wolf and dog minds
may be closely linked
to how the animals
process sensory information
in the earliest weeks of life
Kathryn raised wolf pups
from a very young age
The wolf pups are great
So we get them at
about ten days of age
So at that point,
they can't see,
they can't hear
and they can't smell,
and they can't
really walk either
They're just kind of
little puddles of fur
You basically are a warm water
bottle that feeds them milk
So we bottle feed them
every four hours
It's very intensive,
you're with them 24/7
It's the only way
you can socialize them
There's a brief period of time
when baby animals
are open to new experiences
and become socialized
It's known
as the exploration window,
and it's a chance for them
to learn who and what is safe
while they're protected
from predators
Kathryn found that in wolves,
this window opens very early,
at two weeks,
when only the pups'
sense of smell is working
and they are still
blind and deaf
Over the next few weeks,
the pups start to see and hear,
but also gradually become
more fearful of new sensations
Dog puppies also have
an exploration window,
but it opens slightly later
The big difference is when they
start to explore their world
So dogs don't begin
to explore their world
until four weeks of age,
so that's two weeks later
than the wolves
And so when the dogs
start to explore their world,
they can already
see, hear and smell
But while the dogs have
all their senses powered up
when they're getting
to know their world,
wolves,
with fewer senses working,
will be exposed to far fewer
sensory experiences
before their fear of the
unfamiliar is firmly in place
Kathryn believes this is
one of the main reasons
wild wolves avoid humans
Even a well socialized wolf
is very different
from a well socialized dog
The wolves are more fearful
of novelty in general
than a dog is
Dog puppies can be exposed
to all sorts of sights,
smells and sounds
during their exploration window,
so when they're older,
more things will feel familiar
and they'll be more open
to new situations
This may help explain why dogs
can so easily form close
friendships with other animals,
whether human or not
The ability of dogs to be
flexible is what allowed them
to come into our environment
in the first place
and probably allowed them
to be domesticated
The early wolves
that evolved into dogs
were perhaps quite different
from the wolves of today
As pups, they may have had
a later window of exploration,
leaving them more open
to forming close relationships
with humans
For Kathryn, what might seem
a small difference in timing
during development
has had a profound impact
on how these two animals
use their senses,
and may be a key factor
in creating the dog mind,
comfortable around humans
and primed to become
a close companion
We're so close to our dogs
that some of us imagine
we can guess
what's on their minds
But for scientists,
it's a lot more complicated
One of the big questions,
of course,
that people have always
been interested in is,
do animals think at all?
And in asking that question
about animals,
it makes you think about
what is thought
and what drives
what we are thinking about
For decades, animal researchers
have relied on behavior
to try to determine
how animal minds work
But now things could be changing
because for the first time,
we may have a direct window
inside the animal mind
Neuroscientist Greg Berns
is adapting a medical technique
to study the activity
of brain cells in dogs
Okay, so stand by,
we're going to start the noise
MRI is a technique
that's been used in humans
for over 20 years
Normally, we use it
to study what the brain looks
like,
but with a few tricks,
we can actually do
what we call functional MRI,
which looks at brain activity,
and by analyzing the data,
we can figure out what parts
of the brain are doing what
But doing MRI on animals
is an entirely different game,
mainly because
of the requirement
that the subject has to hold
absolutely still
The need to keep still makes it
impossible to scan most animals
unless they're sedated,
which is not a good way
to study brains in action
One, two, three, steps!
But Greg has teamed up
with Mark Spivak to train dogs
for the unfamiliar conditions
they'll face
inside an MRI machine
One key requirement
is a steady supply of snacks
Well, a lot of humans
have difficulty taking MRI
First of all,
there's the enclosure,
which provokes anxiety
in many humans
Second, there's the absolute
motionlessness required
And then there's the noise
To block out the MRI noise,
the dogs are trained
to wear special ear covers
Without proper conditioning
and training,
the dogs would just run scared
from the MRI
Come here, girl!
Those that pass the test
graduate to the real thing,
like Kady
MRI is a noninvasive technique
at the very cutting edge
of animal science,
and it's beginning to reveal
fascinating insights
Patricia, we're going
to begin the first scan
with the localizer,
are you ready?
One of Greg's earliest
experiments
is revealing an important clue
as to what happens
in a dog's brain
when it receives information
from its senses
First, Kady is looking
at a visual signal
So Kady's in the scanner
right now
and Patricia's actually giving
Kady hand signals
So we've already taught the dogs
through lots of practice
that this means food, okay?
So every time Patricia
puts this signal up,
we're going to be looking
in her brain,
what that brain response is,
and we're actually going to be
looking at a very specific area
called the caudate nucleus
We also have another hand signal
that looks like this,
and that means no reward
After scanning many dogs,
Greg's results reveal
the area of the dog's brain
that responds
If we look very closely,
we find that the area
that's common to all the dogs
corresponds exactly to the same
part of the human brain
that responds to reward
Rewards like money, music, food,
all the things that humans like,
it's also activating
in the dog's brain
Even though Kady
isn't actually seeing food,
she can take a piece
of visual information
and interpret it to anticipate
that she will receive food,
and she's responding
emotionally, just like we do
This was pretty amazing
because it didn't have to be
that way
Dogs could be so different
from us,
they might have responded
completely differently,
but that doesn't seem
to be the case
And this reveals a complex chain
of brain activity
Ever since Pavlov,
people have viewed animals
as Pavlovian machines:
stimulus-response robots,
basically
And what we're finding is that
there's a tremendous amount
of processing
going on in their brains
that looks actually a lot like
what happens to humans
in exactly the same
circumstances
Dogs and probably most animals
have brains and minds
that are far more sophisticated
than we ever
gave them credit for
It's one of the great mysteries:
what are animals thinking?
Now, we are gaining
ever-greater insights
into their senses,
painting a clearer picture
of how the creatures around us
perceive their world,
whether it be dramatically
foreign to our own
or remarkably familiar