00:00:07
we're about to see a simple reflex an
00:00:11
automatic reaction man touches something
00:00:13
hot and withdrawals instantly movement
00:00:17
resulted from a rapid automatic sequence
00:00:19
of signals pass per the nerves no
00:00:21
thought was involved this chicken
00:00:25
panting to cool itself also responds to
00:00:27
heat by reflex action it didn't have to
00:00:29
learn how to pant again no thought is
00:00:32
involved response is automatic a reflex
00:00:36
but simple though reflex actions appear
00:00:39
they involve five separate steps the
00:00:43
first is a change in the environment
00:00:44
called a stimulus which triggers a
00:00:46
response in these examples that stimulus
00:00:49
was heat the second step is a detection
00:00:53
of a stimulus by receptors in this case
00:00:55
sensory nerve endings in the skin step 3
00:01:00
is coordination or processing in this
00:01:03
example sensory neurons pass a message
00:01:06
or impulse to an intermediate neuron in
00:01:08
the spinal cord which processes it and
00:01:10
generates an outgoing impulse this
00:01:13
travels rapidly along a motor neurone to
00:01:15
a muscle
00:01:18
in step 4 this muscle known as an
00:01:21
effector response to the stimulus this
00:01:24
response is the fifth and final step in
00:01:27
the chain of course people can also
00:01:31
respond in more complex ways to stimuli
00:01:33
like the chicken this woman feels hot
00:01:36
but she's learned by experience how to
00:01:38
cool the worker in using this
00:01:40
information she demonstrates a learned
00:01:42
reaction not a reflex scientists often
00:01:46
define learning as a change in behavior
00:01:48
resulting from experience of similar
00:01:51
situations a learned reaction follows
00:01:55
the same basic steps as a reflex
00:01:57
it starts with stimulus and receptor and
00:02:00
ends with effector and response but the
00:02:03
coordination the processing in between
00:02:05
is more complex with the result that
00:02:08
individuals respond differently a reflex
00:02:14
response to a stimulus like this sudden
00:02:16
noise is normally the same in all
00:02:18
members of species and similar in most
00:02:21
species but most learned responses are
00:02:25
the result of signals being processed in
00:02:27
the brain and there they can take any
00:02:29
one of literally billions of different
00:02:31
routes and see one of the simplest we
00:02:34
start at a relay Center which sends a
00:02:37
signal to a thinking decision-making
00:02:38
area of the brain a decision is made the
00:02:42
outgoing impulse passes through the
00:02:44
motor control center down the spinal
00:02:46
cord and connects with a motor neurone
00:02:48
and effector organ as before but it took
00:02:53
a human to process this learned reaction
00:02:55
hen's by contrast our only bird brains
00:02:58
surely they can't learn or think or can
00:03:03
they now here's another uncool customer
00:03:07
dealing with excess heat is this simply
00:03:10
a reflex response in fact this hens been
00:03:14
taught to peck a switch when she feels
00:03:16
too hot which turns off a heater this
00:03:19
involved learning from experience and
00:03:21
the use of some very complex parts of
00:03:23
the brain so this isn't a reflex like
00:03:26
the woman the hen demonstrates a learned
00:03:28
response
00:03:31
animals as well as humans are capable of
00:03:34
using their brains and reacting in a
00:03:36
considered way to changes in their
00:03:37
environment the extent of their learning
00:03:40
and intelligence is much greater than as
00:03:43
realized 50 years ago when these
00:03:45
intensive rearing systems now widely
00:03:47
used in food production were first
00:03:49
devised the ancestors of our farm
00:03:53
animals led active and complex lives in
00:03:55
natural habitats in which learning from
00:03:57
experience was essential to survival are
00:04:01
they content in today's systems which
00:04:03
allow them little to do other than eat
00:04:05
and sleep in recent years animal
00:04:09
behavior scientists have devised ways of
00:04:11
asking animals such questions to
00:04:14
discover what goes on in animals minds
00:04:16
and what they think a need for
00:04:17
satisfactory life the scientists have
00:04:19
looked for answers in the stimulus
00:04:21
response chain by studying animals
00:04:25
responses to stimuli and with
00:04:27
ever-increasing understanding of
00:04:28
coordinating processes in the brain
00:04:31
scientists now know that farm animals
00:04:33
can learn remember reason and predict in
00:04:36
quite remarkable ways their minds and
00:04:39
consequently their needs are very much
00:04:41
more complex and previously realized
00:04:45
still not convinced these aren't just
00:04:47
dumb animals now let's do what the
00:04:50
scientists didn't ask the animals
00:04:52
themselves just what they think and how
00:04:54
they think to do so we too must track
00:04:58
them through each step of the
00:05:00
stimulus-response chain you've seen how
00:05:08
heat can stimulate a response
00:05:11
these animals are reacting to another
00:05:12
environmental stimulus light as the
00:05:17
first light of day dawns free-range hens
00:05:20
take a dust bath animals react to light
00:05:22
by starting to a groom feed explore play
00:05:27
and socialize if they live in an
00:05:30
environment which allows them to do so
00:05:33
light also stimulates hens to start
00:05:36
laying eggs these days usually dim
00:05:39
artificial light as most laying hens are
00:05:42
permanently caged by keeping lights on
00:05:45
17 hours a day
00:05:46
farmers stimulate them to lay more eggs
00:05:50
animals respond to some but not all
00:05:53
stimuli from the first moments of life
00:05:54
some of these piglets were born less
00:05:57
than an hour ago yet already they
00:05:59
respond to stimuli guiding them to their
00:06:01
mothers teeth for milk let's see how
00:06:05
scientists have asked newborn piglets to
00:06:07
reveal which stimuli they perceive and
00:06:10
which they don't this is an artificial
00:06:14
adder it doesn't look like an adder to
00:06:16
us it can hardly do so to a piglet but
00:06:18
the black rubber sac feels like an udder
00:06:21
and is filled with warm water bringing
00:06:23
it to a similar temperature this piglet
00:06:26
responds to the sack as if it were
00:06:28
another it nozzles and attempts to find
00:06:30
a teat tests like this reveal that
00:06:33
newborn piglets respond to stimuli of
00:06:35
warmth and texture but little else but
00:06:42
there's no fooling this piglet a much
00:06:44
more sophisticated character at the age
00:06:46
of just two hours already it's beginning
00:06:49
to respond to additional stimuli such as
00:06:51
color and chemicals detected by the
00:06:53
sense of smell as piglet will have
00:06:56
nothing to do with an udder that looks
00:06:58
and
00:06:58
wrong piglets learn fast like us animals
00:07:05
also respond to constant changes inside
00:07:07
the body the internal stimuli for
00:07:10
instance brain sensors on measuring a
00:07:12
decrease in blood water content cause
00:07:14
thirst hormonal changes inside the
00:07:19
animals stimulate responses involved in
00:07:21
reproduction activities to prepare and
00:07:24
care for the young like this pregnant
00:07:26
sows nest building as well as processes
00:07:29
of mating and birth in intensive systems
00:07:35
such as this animals are still driven by
00:07:38
many internal stimuli prompting complex
00:07:41
behaviors which would help them survive
00:07:42
in the wild
00:07:44
studies reveal the frequent yet futile
00:07:47
attempts of caged hens to nest forage
00:07:50
preen dust bathe and flap their wings
00:07:53
despite lack of material of space in
00:07:56
which to do so by releasing these hens
00:07:59
their feathers pecked and worn for
00:08:01
months in the cage we can discover how
00:08:04
they respond to stimuli they've never
00:08:06
before encountered but first we must
00:08:10
consider how they'll detect such stimuli
00:08:12
which brings us to the second step in
00:08:14
the stimulus response chain the
00:08:16
receptors
00:08:18
[Music]
00:08:28
[Music]
00:08:30
like us animals have eyes to see ears to
00:08:34
hear noses to smell and sensory nerves
00:08:37
with which to feel the sense organs or
00:08:40
receptors as they're called don't assume
00:08:42
these hens see exactly as we see birds
00:08:46
eyesight is considerably more acute than
00:08:49
ours they detect smaller and more
00:08:51
distant things with eyes set to the side
00:08:54
of their heads they also get a wider
00:08:56
panoramic view of everything around them
00:08:58
so these birds depend largely on their
00:09:00
eyes to assess the rich new world of
00:09:02
external stimuli in which they've
00:09:04
suddenly landed sense organs or
00:09:10
receptors of animals differ in
00:09:12
efficiency and capacity from ours
00:09:13
and those of other species some of their
00:09:16
senses are more acute some less some
00:09:19
just different this resting sow shows
00:09:23
the powerful receptor on which pigs
00:09:25
largely depend see how she uses it to
00:09:28
keep an eye on or rather keep a nose on
00:09:31
what's going on around her
00:09:38
pigs as you see can quickly learn to
00:09:41
perform domestic doggy tricks like dogs
00:09:44
they also have hundreds of times our
00:09:46
capacity to detect smells and are
00:09:49
sometimes used to sniff out illegal
00:09:50
drugs by hiding breakfast cereals among
00:09:55
similar sized pebbles and placing them
00:09:58
in an out of sight container we let this
00:10:00
pig show the remarkable capacity of her
00:10:03
scent receptor see how quickly she
00:10:06
smells food
00:10:13
this way she also demonstrates another
00:10:15
highly efficient receptor the tissue
00:10:18
around a pig's mouth is much more
00:10:20
sensitive than our fingertips with this
00:10:22
delicate and discerning sense of touch
00:10:25
she has no difficulty picking out cereal
00:10:27
from the pebbles despite centuries of
00:10:31
domestication and decades of intensive
00:10:34
farming farm animals retain most
00:10:36
behavioral abilities of their wild
00:10:38
ancestors those remarkable scent
00:10:40
receptors still help pigs detect and
00:10:43
respond to stimuli which signal danger
00:10:45
in a way which would have increased
00:10:47
their chances of survival in the wild
00:10:52
these pigs are entering a slaughterhouse
00:10:55
the usual loud noises of slaughter
00:10:58
machinery have caused a previous hour to
00:11:00
urinate in fear now though all is quiet
00:11:03
the pigs
00:11:04
thought to be able to smell an alarm
00:11:06
substance in their predecessors urine
00:11:08
hesitate alarmed and alerted
00:11:14
in sheep ears are particularly efficient
00:11:18
receptors you've heard of a kidnap
00:11:20
you're about to see a lamb nap so that a
00:11:23
you can show us how she uses her sense
00:11:25
of hearing to locate and identify her
00:11:28
own lamb while the user distracted by
00:11:33
food the farmer captures a lamb and
00:11:35
places it in a prepared hide the
00:11:44
mother's identity becomes clear in
00:11:46
seconds she looks around and begins to
00:11:48
call another you appears to respond to
00:11:51
her concern scientists have observed
00:11:53
that sheep often form a close
00:11:55
companionship with another animal in the
00:11:57
flock the you considers the possibility
00:12:05
that the lamb has strayed into the next
00:12:07
field see how in her search she uses her
00:12:12
senses of sight and smell as well as
00:12:15
hearing a light chemical and sound
00:12:18
receptors the lamb is only a few days
00:12:26
old and slow to bleat until he hears his
00:12:29
mother and she hears him even when
00:12:38
several lambs are concealed in different
00:12:40
hides at the same time studies reveal
00:12:42
that each mother can identify our own
00:12:44
lamb by sound alone the lamb is released
00:12:51
see how the mother uses her scent
00:12:53
receptor to confirm that yes this is
00:12:56
indeed her own lamb by now spring is
00:13:06
underway and warm enough for us still
00:13:08
sparsely feathered battery hens to step
00:13:11
out sound into a new world of color
00:13:13
reared indoors these birds have never
00:13:16
even seen the color green yet their eyes
00:13:19
are able to perceive an even wider color
00:13:21
spectrum than ours a broader rainbow
00:13:23
birds have the most complex color vision
00:13:26
of any animal they detect color hues we
00:13:29
cannot see no one knows exactly how
00:13:34
colors appear to them but a bird's eye
00:13:36
view may well be as different from ours
00:13:38
as this what we see is not what they see
00:13:43
their sensitivity to ultraviolet light
00:13:45
also reveals patterns on petals visible
00:13:49
to them but not detected by our own
00:13:51
visual receptors their physical
00:13:57
coordination has much improved since
00:13:59
they released from the cage which didn't
00:14:01
allow the exercise and necessary to
00:14:02
maintain muscle and bone strength
00:14:04
[Music]
00:14:08
now at the next step in the
00:14:11
stimulus-response chain we'll learn how
00:14:13
they and other animals mentally
00:14:15
coordinate and assess stimuli
00:14:20
[Music]
00:14:25
these cars are demonstrating the
00:14:28
simplest form of learned response known
00:14:30
as habituation see how vigorously they
00:14:34
respond to a possible threat when a
00:14:37
scientist opens an umbrella this is a
00:14:39
technique used to train police horses
00:14:41
for crowd control but as the umbrellas
00:14:46
opened again and again they respond less
00:14:49
and less they've learned this stimulus
00:14:51
doesn't signal anything to fear and
00:14:53
incorporated the lessons of experience
00:14:56
into their response animals can also
00:14:59
predict what is about to happen
00:15:01
by employing a form of learning called
00:15:03
classical conditioning they learn to
00:15:06
associate a stimulus with a particular
00:15:08
response these sheep grazing by lane
00:15:11
ignore passing vehicles they too have
00:15:14
learned by habituation not to waste
00:15:16
energy by reacting to something of no
00:15:18
importance to them but a vehicle which
00:15:21
is important to them is about to appear
00:15:26
the farmers Land Rover which brings food
00:15:30
each day they instantly distinguish its
00:15:32
appearance and sound from that of other
00:15:34
vehicles and react appropriately they
00:15:37
learn to associate the Land Rover with
00:15:39
food here by classical conditioning
00:15:43
animals have learned to link something
00:15:45
the farmer does with a particular result
00:15:47
but they can also learn to associate one
00:15:50
of their own actions with a result on
00:15:54
discovering the outcome of an action as
00:15:56
desirable
00:15:57
they often repeat it becoming
00:15:59
increasingly skilled by such trial and
00:16:02
error learning animals become capable of
00:16:05
exerting some control over events
00:16:08
since their release our old friends the
00:16:11
battery hens have learned to run an
00:16:13
obstacle course which demonstrates a
00:16:15
whole range of such learned responses
00:16:19
each hen must pick a key to release a
00:16:22
catch squeeze through a small space
00:16:26
tightrope across a thin pole pack a wire
00:16:32
loop three times to instruct a computer
00:16:34
to release a door
00:16:44
you
00:16:50
take the right turn that a t-junction
00:16:54
and leap over water all in order to
00:16:59
reach a box where she can make an S to
00:17:01
lay her eggs animals ability to learn by
00:17:09
trial and error is put to good use in
00:17:11
some more welfare friendly farming
00:17:13
systems these sours a group housed farm
00:17:17
animals evolved from sociable species
00:17:19
and retain a strong need for
00:17:20
companionship of their own kind
00:17:22
each sow wears her own electronic collar
00:17:26
to enable her to be fed a specific daily
00:17:28
quantity and ensure she doesn't eat her
00:17:31
companions food thus hours have no
00:17:37
difficulty in quickly learning how to
00:17:39
operate this feed station in which a
00:17:41
computer recognizes each color
00:17:43
dispensing food accordingly the animals
00:17:55
can even learn to outsmart the computer
00:17:57
given half a chance those happening to
00:17:59
find spare collars have been discovered
00:18:01
regularly carrying them to the food
00:18:03
dispenser to get a second helping in
00:18:09
behavior patterns like this animals have
00:18:12
learned to link stimuli with events
00:18:14
which will affect them directly but not
00:18:16
every type of learning can be explained
00:18:18
by such links here lambs are engaged in
00:18:22
observational learning in which an
00:18:24
animal learns from another animals
00:18:26
experience see how the milk fed lamb
00:18:29
explores his mother's concentrated food
00:18:32
later in life he will only accept it
00:18:34
himself by recalling this early learning
00:18:37
Australian farmers shipping live lambs
00:18:40
on long journeys to slaughter find those
00:18:42
lacking this learning experience will
00:18:44
starve to death rather than eat
00:18:46
concentrates
00:18:47
[Music]
00:18:49
the mental ability required for
00:18:52
observational learning is more
00:18:53
sophisticated than that employed in
00:18:55
gaining immediate rewards yet like you
00:18:58
these hens are learning by watching a
00:19:01
video the hen in the video eats food
00:19:04
from a red container so let's see what
00:19:08
happens when we offer them food hidden
00:19:10
under sawdust in similar containers some
00:19:12
red but others yellow the first hen
00:19:17
immediately goes to a red dish
00:19:19
[Music]
00:19:21
the second glances at a yellow dish to
00:19:24
cause what she's learned from the video
00:19:26
then she too chooses the red scientific
00:19:30
tests show the hens using their brains
00:19:32
to make this choice over and over again
00:19:36
[Music]
00:19:42
brain power is of little use without
00:19:44
muscle power dat translate thought into
00:19:47
action muscles are effective which
00:19:50
finally add response to the chain of
00:19:52
events which began with a stimulus this
00:19:55
cow sensing flies deals with them with a
00:19:58
modicum of muscle power like this but in
00:20:04
response to more serious threats
00:20:06
internal effectors also affect movement
00:20:08
preparing the body for fight-or-flight a
00:20:11
[Music]
00:20:13
heartbeat monitor strapped to this calf
00:20:15
allows us to hear its internal response
00:20:18
to alarm at the sight of a dog listen to
00:20:21
the quickening beat of the heart pumping
00:20:23
out blood to prime other muscle tissues
00:20:31
[Music]
00:20:37
at the same time a second internal
00:20:39
effector the adrenal gland sends natural
00:20:42
chemicals stimulants surging into the
00:20:44
blood together they boost the body's
00:20:46
capacity to react to stress with
00:20:48
efficiency or speed however internal
00:20:53
responses to prolonged or severe stress
00:20:56
can threaten the health of both animals
00:20:57
and humans in Barren rearing systems
00:21:03
like this widely used in pork and bacon
00:21:06
production piglets have no straw or
00:21:09
other stimuli they live on metal slats
00:21:11
bounded by concrete walls and respond by
00:21:15
biting and chewing each other's bodies
00:21:16
and fighting having nothing else to do
00:21:19
nothing to explore surveys reveal
00:21:22
children to be more likely to catch
00:21:24
curls during exam periods at school
00:21:26
a mild result of increased stress but
00:21:29
for these piglets every day is a severe
00:21:32
test a test of endurance
00:21:39
the weakest animals suffer most and such
00:21:42
chronic stress can result in diarrhea
00:21:44
illness and stunted growth
00:21:54
these piglets of the same breed are
00:21:57
among the few now read free-range in an
00:22:00
environment providing ample stimuli to
00:22:02
which they can respond
00:22:04
[Music]
00:22:15
see the difference environment makes to
00:22:17
their behavior even the runt little more
00:22:20
than half the size of some of his
00:22:22
siblings plays and thrives free from
00:22:25
stress and bullying
00:22:27
[Music]
00:22:32
studies reveal that rough handling by
00:22:35
humans can also stunt animal's growth
00:22:38
and result in this kind of fearful
00:22:40
response but these timid piglets have
00:22:45
not been roughly treated by humans the
00:22:47
environment an animal is given and the
00:22:50
extent to which it satisfies its
00:22:51
behavioral needs will also strongly
00:22:54
influence its response to humans as well
00:22:56
as to pen mates
00:23:03
these piglets have been treated in the
00:23:05
same way by humans but given these
00:23:07
playthings see the difference in their
00:23:10
behavior their friendly response and
00:23:17
lack of fear result entirely from the
00:23:19
fact that unlike the others they've been
00:23:21
given the means to help satisfy this
00:23:23
strong exploratory needs in systems like
00:23:29
this still used in many countries
00:23:31
animals respond to near total lack of
00:23:34
stimuli with abnormal repeated behaviors
00:23:36
called stereotype is see how this sow
00:23:43
repeatedly mouths the bar another
00:23:46
typical stereotyped behavior is moving
00:23:49
the head from side to side such
00:23:53
responses may indicate that animals are
00:23:55
withdrawing into a world of their own
00:23:57
becoming less aware perhaps of their
00:24:00
unacceptable but inescapable environment
00:24:04
[Music]
00:24:06
now released from her equally barren
00:24:09
cage this hen eagerly steps into a nest
00:24:12
a luxury she's never known before but is
00:24:15
it a luxury or need animals can tell us
00:24:20
what they really need by showing they're
00:24:22
prepared to pay a price for it as they
00:24:24
did in our obstacle course in scientific
00:24:27
tests hens prove willing to pay a very
00:24:30
high price for a nest passing many
00:24:32
unpleasant obstacles to convince
00:24:34
scientists that this is indeed a
00:24:36
compelling need but this hen now has a
00:24:42
nest already comfortably arranged by one
00:24:45
of her companions so why is she picking
00:24:47
up straw to remake it because a study
00:24:51
show animals also need to be actively
00:24:53
involved in providing for their own
00:24:55
requirements
00:24:58
given the choice for instance of food
00:25:01
that's easily available or the
00:25:03
opportunity to forage for it they
00:25:05
frequently choose to forage by showing
00:25:13
how they can respond to stimuli animals
00:25:16
have taught us that they are not
00:25:17
otamatone see an intelligent machine
00:25:19
like creatures they've demonstrated
00:25:24
their frustration when denied any
00:25:26
opportunity to respond to inner stimuli
00:25:28
which still drive them they've shown the
00:25:33
remarkable capacities of their receptors
00:25:35
to detect stimuli while sometimes
00:25:39
responding to simple events with rapid
00:25:41
automatic reflexes they've revealed how
00:25:45
most of their behavior results from a
00:25:47
more complicated chain of events between
00:25:49
stimulus and response this involves
00:25:52
learning remembering predicting and even
00:25:55
conscious decision making by following
00:26:00
this chain of events we've begun to
00:26:02
solve the mystery of what goes on inside
00:26:04
the minds of the animals and what they
00:26:07
need to use their full capacities and
00:26:10
live contentedly in a stimulating world
00:26:12
[Music]
