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Hello and welcome.

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I'm Lucy Cooke, and I'm going
to be taking you into the hidden

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world of one of Britain's
most endangered and least

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understood animals, bats.

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Bats are mammals like us.

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Yet they're as alien
<font color="

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They're the only ones that can fly.

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They see the world using sound...

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BATS SQUEAKING

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..and spend most of their life
in total darkness.

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They're hard enough to spot,
let alone study.

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<font color="
science to uncover

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their surprising secrets.

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We've come to Bryanston, in Dorset,

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which is home to one of the UK's

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most important bat roosts.

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Inside this old building is a colony
of greater horseshoe bats,

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<font color="

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And we've been following
it for half a year.

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We've seen the arrival
of a new generation.

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Discovered how their extraordinary
bodies work...

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That seems incredible that
it's able to function

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<font color="

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..and enter their strange
and complex social world.

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Just so fantastically weird.

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Today, we've brought together
scientists and conservationists

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for an event vital to the
survival of the roost.

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<font color="

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Later on, we're hoping to witness
the crucial moment when some

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of the baby bats born here
over the last few weeks,

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leave the roost and fly out
for the first time.

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This is Bryanston in Dorset.

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<font color="
home to far more bats than people.

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Our greater horseshoe colony
has taken over what was once

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the kitchens of
an 18th century mansion.

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It's now protected, part
of a nationwide drive

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<font color="

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Earlier in the year, we installed
a night vision camera

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in the heart of the roost.

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And today we're monitoring it from
our marquee headquarters close by.

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With me to take a first look
inside is Dr Anita Glover,

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<font color="
who takes care of this roost.

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Anita, is that a cluster
of pups in the bottom?

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Yeah, so that darker cluster
that you can see at the bottom

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is all young bats kind of crushed
together, which is something

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<font color="
go out to forage,

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is they'll put the bats
into this huddle.

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Oh, look, here we go, this
is the mum testing her wings.

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And you really get a sense of that
40 centimetre wingspan.

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<font color="
the skills they need

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to fly in the safety
of the roost.

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Now, this is one of the young pups
that's hanging onto the head

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of its mother and practising
flapping its wings.

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<font color="
know how the mother

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is holding on.

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This is the very, very first
inkling of flight,

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and I just love these images.

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I think they're fantastic.

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Tonight, we hope to see
some of these pups take

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<font color="

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It's a vital milestone,
because the future of the roost

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depends on this next generation.

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And Bryanston is one of only 35
greater horseshoe breeding colonies

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in the whole of Britain.

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Both their range and their numbers
<font color="

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compared to a century ago.

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I've heard that in the UK,
populations have actually crashed

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of greater horseshoe bats
by up to 90%.

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I'm assuming that humans
are involved in this somehow?

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Yeah, sadly, yes.

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<font color="
land-use change the use

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of pesticides, which has affected
food availability for them.

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But also the destruction
of their roosts.

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Bats need a safe, dark space
away from predators.

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<font color="
and in one section,

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Anita's team have built an enclosure
that's specially heated

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for mothers to have their young,

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a wire mesh makes it easy
for the pups to grip on.

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You've had some success here,
<font color="

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We have, so we took this building
on in 1994,

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and there was less than 100 bats
in the roost at that point.

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And over time, through protection
of the site,

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we've actually seen that number
increase to over 300 now.

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<font color="
them as they fly out,

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to monitor how the colony's doing.

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But greater horseshoes aren't
the only bats we're following here.

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You might be surprised to know
that bats make up a quarter

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of all mammal species in Britain.

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<font color="

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From tiny pipistrelles, as small
as a pound coin...

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..to noctules, as big as a starling.

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Bryanston is a hot spot.

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It's thought that over half our
native species live here,

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each with its own unique place
<font color="

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To study them, we've brought in
a battery of technology,

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cutting edge cameras to capture
their behaviour, and ultrasonic

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recording devices, audio
moths that detect back calls

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beyond the range of our hearing.

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<font color="
is installing them

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in places where we hope to find
significant bat traffic.

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First one's going by the clock
tower, where it's suspected

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there might be a roost
of pipistrelles.

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<font color="
bats roost in this clock tower,

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but nobody knows for sure.

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So this wonderful device will record
the sounds emitted by the bats here.

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And then, to a reasonable degree
of accuracy,

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it will be able to tell us what
<font color="

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Some types of bat forage
close to water,

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so he's putting another audio
off by the river.

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We'll look at the results later,
and if we find any new roosts,

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they can be protected.

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It's largely thanks
<font color="

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that our greater horseshoe
roost has thrived.

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We began following it long
before the new generation

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of pups was born.

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I first came here five months ago
on a cold March morning.

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<font color="

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we needed a special license
in order to enter.

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Of all the animals I've studied
and written about, from sloths

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to frogs, bats are among
the most otherworldly.

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So what do you think
<font color="

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It's pretty chilly, I think.

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Well, I think it's probably
about eight or nine degrees,

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but the wind chill is probably
making it feel a bit colder. Yeah.

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Winter is a dangerous time for our
<font color="

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insects to eat.

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To survive it, they have
to hibernate.

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Do we need to whisper?

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No, but we'll just talk quietly.

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Talk quietly, OK.

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I'll do my best, it's not one
of my special specialities.

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<font color="
a state called torpor.

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Their body temperature drops
and their vital systems slow down,

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reducing their need for food.

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Gosh, it's like a maze in here.

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There is this one.

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It would be fascinating to know the
<font color="

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It would.

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Ruud is here and he's got
a thermal imaging camera

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that's going to enable us to see
what temperature that bat is.

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Is that really...

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The bat is only eight and a half
<font color="

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Wow, that's pretty much
the temperature of the room.

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That seems incredible that it's able
to function at such

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a low temperature.

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When active, bats need to maintain
a body temperature

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<font color="
like most mammals, including us.

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But in torpor, this can fall
to as low as five degrees

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and their heart rate slows
to just ten beats a minute.

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It's just absolutely mind-blowing
to think about what's

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<font color="
of that animal right now.

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How they managed to pull
off that physiological feat

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of allowing themselves to survive
that degree of hypothermia.

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In here, you've got relatively
stable, cool, humid temperatures.

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<font color="
for in hibernation.

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Chilly, though. I know, my nose
is cold. Mine is.

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My nose keeps running, it's so cold.

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Bats are thought to have evolved
in the tropics.

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<font color="

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they hibernate often
in extraordinary ways.

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In Japan, the tube-nosed bat makes
itself a little igloo in the snow,

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where it hides away for the winter.

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In this footage, the spring thaw
has melted the roof off its snow den

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<font color="

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In cities, bats can be even
more ingenious.

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These pipistrelles in Holland
are hibernating

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in the cavity walls of a tower
block, like living insulation.

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At Bryanston, Anita and I search
<font color="

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moving softly so as not
to disturb them.

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Gosh, it's a bit of a mission
to get up here isn't it?

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Definitely hidden themselves away.

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Wow!

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There's a lot more in here,
aren't there?

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<font color="
to say how many there are.

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Just so fantastically weird.

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I love bats, so cool.

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What makes all this especially
bizarre is that many

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of the hibernating females have
a sperm bank inside them.

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<font color="
but haven't yet

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started their pregnancy.

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Instead, they keep the sperm alive
in their body through the winter.

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When spring comes, they use
it to fertilise an egg

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and the pregnancy finally begins.

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<font color="
in the attic

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have continued to follow
the colony's progress.

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We've captured remarkable footage
of pregnant females

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and the arrival of their pups,
which has never

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been witnessed here before.

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<font color="
and leading bat scientist,

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Professor Kate Jones.

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So here we have a few weeks ago
when the mums are still pregnant.

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And I think it's just astonishing
to see how large they are, really.

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I mean, look at that, looks like
<font color="

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You can now see just how big
her abdomen is.

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And inside is a baby
that when it's born,

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is going to be up to a third
of its mother's body weight.

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Normally in mammals, it's only
<font color="

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So that's an enormous weight
on the mother.

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The females will have just one pup
a year, but can have many

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over a lifetime, as they sometimes
live as long as 30 years.

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Anita hopes there'll be at least
<font color="

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to ensure the roost continues
to grow.

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Here, we've got a baby. Oh,
wow, that's cool.

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That looks like it's pretty young.

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It's like a mini dragon.

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Yeah, it is, that that's
<font color="

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When they're in their first few
days, they just have huge wings

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and a huge nose leaf and it doesn't
seem to be much

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in the way of a head and body,
so they got, sort of,

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some growing into their appendages
<font color="

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This footage shows a pup
in the earliest days of life.

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They're born naked and blind...

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..but develop rapidly.

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This pup is about a week old.

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Its eyes are now open and it has
a light covering of fur.

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<font color="
babies on this one.

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That's really uncommon for most
UK bat species

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to actually have twins.

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So it's just possible that it was
another pup that clambered

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on and the mother tolerated it.

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<font color="
weeks to grow and develop,

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ready for their first flight.

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It's the most dangerous
moment of their young lives.

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And Kate's been finding out why.

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In this quiet suburban street
in Kent,

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<font color="

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Here, Hazel Ryan looks after
lost and injured bats.

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Today, she's returning a pup to his
roost at the top of a chimney.

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Found close to death, Hazel's
nurtured him back to health.

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Still too young to fly, the pup
<font color="

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and the smells of his colony.

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Just one of the 100 or so bats
Hazel has cared for this year.

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So this is one of my best
rehabilitation rooms,

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and it's a bit full at the moment,
it's a really busy time of year.

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<font color="
34? Wow!

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This little one here, Yorkletts,
he's one we've had...

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Yorkletts? Yeah.

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Well, we named them after where
they came from,

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so he came from a village
<font color="

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It's a bit sad really, because
he was caught by cat.

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We think he was probably only
on his first or second flight out.

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He's just at the stage where
he's learning to fly

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<font color="
his wings.

244
00:15:26,360 --> 00:15:30,080
We've had him for a little
while and you'll see the holes

245
00:15:30,080 --> 00:15:32,240
are actually beginning to heal.

246
00:15:32,240 --> 00:15:34,040
Oh, I see, those are the holes.

247
00:15:34,040 --> 00:15:36,600
You can see the little
puncture wounds.

248
00:15:36,600 --> 00:15:40,840
<font color="
allowing their skin to heal

249
00:15:40,840 --> 00:15:44,600
amazingly quickly, ten times
faster than human skin.

250
00:15:47,200 --> 00:15:51,280
While the bats are recovering,
Hazel has to hand feed them.

251
00:15:51,280 --> 00:15:53,880
The older ones munch on mealworms.

252
00:15:55,720 --> 00:15:59,840
The younger bats, like Yorkletts,
<font color="

253
00:15:59,840 --> 00:16:01,920
I'm testing the temperature.

254
00:16:01,920 --> 00:16:04,160
Yeah, I just touch my top lip...

255
00:16:04,160 --> 00:16:05,960
..as you would with a baby's bottle.

256
00:16:05,960 --> 00:16:08,320
OK, so... It should feel warm
but not hot. OK.

257
00:16:09,480 --> 00:16:12,600
And then if you try... It's kind
<font color="

258
00:16:12,600 --> 00:16:14,440
The side of the mouth. Hello.

259
00:16:14,440 --> 00:16:15,800
Come on, Dude.

260
00:16:21,280 --> 00:16:24,160
Once they get the hang of it,
they will just latch onto the end

261
00:16:24,160 --> 00:16:25,440
of the pipette.

262
00:16:25,440 --> 00:16:27,560
Because, of course,
they're mammals, just like us,

263
00:16:27,560 --> 00:16:29,680
<font color="
He's so tiny that...

264
00:16:29,680 --> 00:16:30,920
Yeah, you're worried.

265
00:16:30,920 --> 00:16:33,280
I'm worried that I'm going
to drown him in milk.

266
00:16:34,640 --> 00:16:38,720
As they recover, Hazel gives
her bats flight training.

267
00:16:38,720 --> 00:16:42,320
She does it here
in a specially-built cage.

268
00:16:43,560 --> 00:16:47,480
<font color="
to bring in specialist cameras

269
00:16:47,480 --> 00:16:49,920
to observe bat flight and detail.

270
00:16:53,640 --> 00:16:57,240
Today, Hazel has two bats
of different species

271
00:16:57,240 --> 00:17:00,400
with different flying techniques.

272
00:17:00,400 --> 00:17:03,320
First, the aptly-named brown
long-eared bat.

273
00:17:08,000 --> 00:17:12,120
<font color="
slow but manoeuvrable.

274
00:17:12,120 --> 00:17:15,000
Essential to navigate
through foliage,

275
00:17:15,000 --> 00:17:17,280
to snatch insects from leaves.

276
00:17:22,720 --> 00:17:27,320
Those ears are incredible and
therefore picking up tiny, tiny

277
00:17:27,320 --> 00:17:31,240
insect sounds that are
<font color="

278
00:17:31,240 --> 00:17:34,720
Next, a pipistrelle
Britain's commonest bat.

279
00:17:35,720 --> 00:17:40,120
Slimmer wings give it a
smoother, faster flight.

280
00:17:40,120 --> 00:17:43,200
It can reach speeds
of up to 30km an hour,

281
00:17:43,200 --> 00:17:46,840
ideal for capturing insects
out in the open.

282
00:17:50,920 --> 00:17:55,080
<font color="
and the speed of the bat

283
00:17:55,080 --> 00:17:58,720
can tell you so much about its
biology and what it's feeding on

284
00:17:58,720 --> 00:18:00,640
and where its foraging.

285
00:18:04,600 --> 00:18:07,920
But the pipistrelle is a slow coach
compared to the fastest bat

286
00:18:07,920 --> 00:18:10,440
in the world.

287
00:18:10,440 --> 00:18:12,960
<font color="
has been clocked

288
00:18:12,960 --> 00:18:16,400
at an astonishing 160km
an hour.

289
00:18:16,400 --> 00:18:20,240
Speedier in level flight
than the fastest bird.

290
00:18:22,360 --> 00:18:25,680
But what makes bats such
accomplished flyers

291
00:18:25,680 --> 00:18:28,680
is their extraordinary wings.

292
00:18:28,680 --> 00:18:32,040
<font color="
of a bat in flight,

293
00:18:32,040 --> 00:18:34,240
filmed in a lab in the States.

294
00:18:35,560 --> 00:18:40,200
It reveals how their wings are based
on the same anatomy as our hands,

295
00:18:40,200 --> 00:18:42,880
but with massively
elongated fingers.

296
00:18:44,040 --> 00:18:46,320
The forefingers make
up most of the wing...

297
00:18:47,760 --> 00:18:52,200
<font color="
a claw sticking out the front.

298
00:18:56,520 --> 00:19:00,080
Before a bat can take off, its wing
muscles need to be warmed up.

299
00:19:01,960 --> 00:19:05,280
To find out how,
ecologist Dr Liat Wicks

300
00:19:05,280 --> 00:19:09,000
uses a thermal camera
to record the temperature.

301
00:19:09,000 --> 00:19:11,520
<font color="
inactive for a while,

302
00:19:11,520 --> 00:19:14,000
so it's appearing
cooler against the hand.

303
00:19:14,000 --> 00:19:16,840
To be able to fly and sort
of kick start their muscles,

304
00:19:16,840 --> 00:19:19,120
they need to warm up quite quickly.

305
00:19:19,120 --> 00:19:23,440
So what they have is
something called brown fat.

306
00:19:23,440 --> 00:19:27,000
<font color="
between the shoulder blades

307
00:19:27,000 --> 00:19:29,840
and it can be burned to
produce extra internal heat.

308
00:19:31,000 --> 00:19:33,440
So it'll take some minutes,
and once it's warmed up

309
00:19:33,440 --> 00:19:36,360
to its optimum flight
temperature, it'll then become

310
00:19:36,360 --> 00:19:38,840
<font color="

311
00:19:39,800 --> 00:19:42,720
Once in the air, bats have
the opposite problem...

312
00:19:42,720 --> 00:19:45,120
..cooling down.

313
00:19:45,120 --> 00:19:48,600
Because they flap their
wings up to 12 times a second,

314
00:19:48,600 --> 00:19:51,480
their muscles produce so
much heat it puts the bat

315
00:19:51,480 --> 00:19:53,160
<font color="

316
00:19:55,400 --> 00:19:58,800
The bat's body appears very,
very hot, sometimes hotter

317
00:19:58,800 --> 00:20:00,840
than a human face
on the infrared. Wow!

318
00:20:00,840 --> 00:20:03,240
Whereas the wings
are relatively cool.

319
00:20:03,240 --> 00:20:05,400
So where are they
losing energy from?

320
00:20:05,400 --> 00:20:06,840
<font color="

321
00:20:06,840 --> 00:20:10,120
A recent study showed that they
lose the majority of their heat

322
00:20:10,120 --> 00:20:13,720
from their body, but it's still
how - how are they doing that?

323
00:20:13,720 --> 00:20:17,480
Right. So we're looking at how
maybe it's radiating through

324
00:20:17,480 --> 00:20:20,200
<font color="
early stages with baseline

325
00:20:20,200 --> 00:20:24,720
data collection, but we
are testing those theories.

326
00:20:24,720 --> 00:20:28,320
Research like this is revealing
the intricate natural engineering

327
00:20:28,320 --> 00:20:31,440
that makes bats such amazing flyers.

328
00:20:40,800 --> 00:20:43,480
Back at Bryanston,
<font color="

329
00:20:43,480 --> 00:20:45,800
are progressing
through flight school.

330
00:20:47,000 --> 00:20:49,600
They have to work their way
up through a number of stages

331
00:20:49,600 --> 00:20:51,760
before they can fly solo.

332
00:20:51,760 --> 00:20:54,600
First, the wings stretch.

333
00:20:56,600 --> 00:20:59,280
Next, the frenetic flap.

334
00:20:59,280 --> 00:21:01,920
This exercises
<font color="

335
00:21:03,160 --> 00:21:05,880
Here, a large pup
is flexing its wings

336
00:21:05,880 --> 00:21:08,160
while still clinging to its mother.

337
00:21:10,360 --> 00:21:13,440
Finally, they attempt
the micro test flight

338
00:21:13,440 --> 00:21:15,640
in the safety of the roost.

339
00:21:18,040 --> 00:21:21,600
This aerial debut lasts
just six seconds.

340
00:21:23,680 --> 00:21:27,280
<font color="
simply have to let go.

341
00:21:28,480 --> 00:21:31,960
It's a key advantage
of hanging upside down.

342
00:21:31,960 --> 00:21:34,880
The tendons in the bats'
claws make them clamp shut

343
00:21:34,880 --> 00:21:37,200
when bearing its body weight.

344
00:21:38,840 --> 00:21:41,920
This means no energy
is required to hang,

345
00:21:41,920 --> 00:21:43,800
<font color="

346
00:21:43,800 --> 00:21:45,880
even months at a time,

347
00:21:45,880 --> 00:21:48,000
until they need to take flight.

348
00:21:50,240 --> 00:21:53,000
Recent research, in America,
has been revealing

349
00:21:53,000 --> 00:21:56,240
the remarkable ways
different bats take off.

350
00:21:58,640 --> 00:22:04,480
Most bats, really, they
<font color="

351
00:22:04,480 --> 00:22:07,360
and they kind of just fall,
and then start... Fall and fly.

352
00:22:07,360 --> 00:22:08,640
Fall and fly. Yeah.

353
00:22:08,640 --> 00:22:11,400
But there's also
the vampire bats.

354
00:22:11,400 --> 00:22:15,640
So, this one feeds on blood,
but it's usually on cattle,

355
00:22:15,640 --> 00:22:19,000
<font color="
running around on the ground.

356
00:22:19,000 --> 00:22:22,640
So, it's learnt to leap
from a standing point

357
00:22:22,640 --> 00:22:24,560
up about three feet in the air.

358
00:22:24,560 --> 00:22:26,160
Have a look at this.

359
00:22:29,240 --> 00:22:32,440
Wow, that's amazing!
It's like a Harrier jump jet.

360
00:22:32,440 --> 00:22:37,520
<font color="
the blood from a cow's foot,

361
00:22:37,520 --> 00:22:40,280
you've got to make a quick escape.

362
00:22:40,280 --> 00:22:42,240
Their muscles are so large,

363
00:22:42,240 --> 00:22:46,200
and it's using its claws
there to propel itself up,

364
00:22:46,200 --> 00:22:49,720
and also giving it direction
once it's left the ground.

365
00:22:49,720 --> 00:22:52,280
<font color="

366
00:22:52,280 --> 00:22:55,000
Now, landing, that's
really counterintuitive.

367
00:22:55,000 --> 00:22:58,400
Landing is my favourite,
this is the coolest part.

368
00:22:58,400 --> 00:23:02,520
Bats have got to land on
surfaces that are above it,

369
00:23:02,520 --> 00:23:07,400
so it's got to try and somehow
<font color="

370
00:23:08,400 --> 00:23:10,520
So, it slows down,

371
00:23:10,520 --> 00:23:12,800
it flips around,

372
00:23:12,800 --> 00:23:14,280
and then lands.

373
00:23:14,280 --> 00:23:18,200
So, this is the most amazing
acrobatics I've ever seen.

374
00:23:18,200 --> 00:23:21,280
It closes one of its wings -
that makes it roll -

375
00:23:21,280 --> 00:23:25,960
and then it uses its inertia to grab
<font color="

376
00:23:25,960 --> 00:23:29,120
So, it's using the speed of
its flight to create the inertia

377
00:23:29,120 --> 00:23:32,400
to then land. That's called
a two-point landing.

378
00:23:40,320 --> 00:23:42,920
But where exactly do
bats go when they fly out

379
00:23:42,920 --> 00:23:45,440
of their roosts at night?

380
00:23:45,440 --> 00:23:48,880
<font color="
research is happening in Bulgaria,

381
00:23:48,880 --> 00:23:53,000
which has more types of bat
than almost anywhere in Europe.

382
00:23:57,680 --> 00:24:02,720
These limestone caves are home
to 3,000 greater mouse-eared bats.

383
00:24:04,520 --> 00:24:08,840
Dr Stefan Greif and Laura Stussholt
are investigating exactly

384
00:24:08,840 --> 00:24:13,280
<font color="
what insects they eat.

385
00:24:13,280 --> 00:24:15,840
At dusk, they assemble
a special trap

386
00:24:15,840 --> 00:24:18,560
to catch some bats
without harming them.

387
00:24:20,880 --> 00:24:22,640
This is a harp trap.

388
00:24:24,320 --> 00:24:27,400
The bat flies into these
nylon strings, and then,

389
00:24:27,400 --> 00:24:29,240
<font color="

390
00:24:29,240 --> 00:24:32,280
..it glides down and
falls into this bag.

391
00:24:37,720 --> 00:24:39,880
Next, they're going to take a bat

392
00:24:39,880 --> 00:24:45,280
and attach a sophisticated GPS
tag that can track its movements.

393
00:24:45,280 --> 00:24:48,160
Now we put some glue
on the back of the bat.

394
00:24:48,160 --> 00:24:52,680
<font color="
that they also use on humans,

395
00:24:52,680 --> 00:24:56,640
so it's not harmful to the
bat, and it actually dissolves

396
00:24:56,640 --> 00:25:01,680
after a few days again. So the
tag would fall off by itself.

397
00:25:01,680 --> 00:25:05,080
We prefer to recapture
the bat with the tag on,

398
00:25:05,080 --> 00:25:08,160
<font color="
can get our tag back.

399
00:25:08,160 --> 00:25:12,400
So, now this guy is finished
and we can actually release him.

400
00:25:12,400 --> 00:25:15,520
The tag also contains
a tiny microphone

401
00:25:15,520 --> 00:25:18,240
to record the sounds
of the bat feeding,

402
00:25:18,240 --> 00:25:22,200
and from that they can tell
<font color="

403
00:25:32,040 --> 00:25:34,760
But to retrieve all this
information, Stefan and Laura

404
00:25:34,760 --> 00:25:37,040
need to recapture the bats.

405
00:25:37,040 --> 00:25:40,200
Now they're going to seek out
one they tagged last night,

406
00:25:40,200 --> 00:25:43,960
a single bat amongst 3,000.

407
00:25:48,800 --> 00:25:50,800
It can get quite busy in here.

408
00:25:50,800 --> 00:25:54,160
<font color="
when they fly all around your head.

409
00:25:57,400 --> 00:25:59,600
It's over here.

410
00:25:59,600 --> 00:26:01,160
You got it?

411
00:26:02,640 --> 00:26:04,240
Got it.

412
00:26:06,360 --> 00:26:07,800
Yay!

413
00:26:07,800 --> 00:26:09,280
There we go.

414
00:26:13,240 --> 00:26:18,640
Back at the research station, Stefan
and Laura download the GPS data.

415
00:26:18,640 --> 00:26:23,600
<font color="
bat flew 22km nonstop,

416
00:26:23,600 --> 00:26:28,240
touched down for 90 minutes in a
wheat field to refuel on insects,

417
00:26:28,240 --> 00:26:30,400
then returned home to the cave.

418
00:26:31,600 --> 00:26:34,320
By using these GPS tracks,
we can find out

419
00:26:34,320 --> 00:26:37,600
where the bats are hunting
<font color="

420
00:26:37,600 --> 00:26:39,760
Which means it's important for us

421
00:26:39,760 --> 00:26:43,600
to make sure that these feeding
grounds are kept preserved.

422
00:26:43,600 --> 00:26:47,960
So, these GPS tracks
can help in conservation.

423
00:26:49,320 --> 00:26:53,160
Next, they listen to the audio
recordings of the bat feeding.

424
00:26:53,160 --> 00:26:56,040
<font color="
through a hard shelled beetle.

425
00:26:59,080 --> 00:27:02,120
They're a little bit crunchy,
and they go on for a long time.

426
00:27:02,120 --> 00:27:04,120
So, we've got a big meal this time.

427
00:27:05,160 --> 00:27:08,920
Then, something a
bit softer - a moth.

428
00:27:08,920 --> 00:27:12,360
So, this is the sound of
<font color="

429
00:27:12,360 --> 00:27:14,000
They're a little bit weaker

430
00:27:14,000 --> 00:27:16,400
and they're not as
crunchy as the beetles.

431
00:27:18,560 --> 00:27:22,280
We get a good sense of the numbers
of the prey that they're eating.

432
00:27:22,280 --> 00:27:26,040
How many insects per night,
on the ground and in the air.

433
00:27:26,040 --> 00:27:29,320
<font color="
of the intake, basically.

434
00:27:29,320 --> 00:27:33,560
So, that means that we can
start to quantify the impact

435
00:27:33,560 --> 00:27:35,960
they have in the ecosystem.

436
00:27:35,960 --> 00:27:39,520
Research like this shows
the important role bats play

437
00:27:39,520 --> 00:27:42,520
in keeping insect
<font color="

438
00:27:42,520 --> 00:27:46,200
The more we learn, the more
we can appreciate bats.

439
00:27:48,280 --> 00:27:50,920
But it hasn't always been this way.

440
00:27:55,320 --> 00:27:57,760
Bats have been feared
throughout history,

441
00:27:57,760 --> 00:28:00,840
and even today they're
shrouded in myths.

442
00:28:05,520 --> 00:28:08,920
When I say I study bats, people
<font color="

443
00:28:08,920 --> 00:28:11,560
And when they say that to me, I say,
"Well, they've got a sophisticated

444
00:28:11,560 --> 00:28:14,480
echolocation system. What would
they be doing in your hair?"

445
00:28:14,480 --> 00:28:16,880
I think it's that thing of
them being slightly in-between

446
00:28:16,880 --> 00:28:19,520
<font color="
of neither one thing or another,

447
00:28:19,520 --> 00:28:22,000
and that's a bit
creepy in a way. Yes.

448
00:28:22,000 --> 00:28:25,040
Even in the Bible, in the Book
of Leviticus in the Old Testament,

449
00:28:25,040 --> 00:28:27,600
bats are described as being unclean.
<font color="

450
00:28:27,600 --> 00:28:30,760
In the Middle Ages, there was,
you know, that was a sort of...

451
00:28:30,760 --> 00:28:34,120
European artists were
depicting the devil as a bat.

452
00:28:34,120 --> 00:28:38,600
In Dante's Inferno, when talking
about the wings of Satan,

453
00:28:38,600 --> 00:28:41,440
he says, "They're not feathered
<font color="

454
00:28:41,440 --> 00:28:43,880
"They're bat-like and leathery,
each fanned away the air."

455
00:28:45,760 --> 00:28:48,280
In the black and white world
of Christian morality -

456
00:28:48,280 --> 00:28:50,480
angels had bird wings.

457
00:28:50,480 --> 00:28:52,640
Demons, bat wings.

458
00:28:53,800 --> 00:28:56,880
The nail in the coffin was
<font color="

459
00:28:56,880 --> 00:28:59,480
were discovered in the 17th century.

460
00:29:00,760 --> 00:29:04,400
The author Bram Stoker kept
among his papers an article

461
00:29:04,400 --> 00:29:08,520
that mentioned these "vampire bats,"
now thought to have influenced

462
00:29:08,520 --> 00:29:12,000
his famous creation - Count Dracula.

463
00:29:12,000 --> 00:29:14,600
Bats became fully
<font color="

464
00:29:14,600 --> 00:29:18,200
and I think it's just incredibly
unfair, isn't it, Kate?

465
00:29:18,200 --> 00:29:20,840
Well, I love bats,
so I would say that.

466
00:29:20,840 --> 00:29:24,360
But they have all these services
that they provide to us.

467
00:29:24,360 --> 00:29:27,680
So, they have this huge
role in insect control.

468
00:29:27,680 --> 00:29:30,080
<font color="

469
00:29:30,080 --> 00:29:34,480
There's a study in Texas
where they were looking at

470
00:29:34,480 --> 00:29:38,000
how well the bats were controlling
the insects on this cotton crop,

471
00:29:38,000 --> 00:29:40,640
and they estimated it was about
a third of the value of the crop

472
00:29:40,640 --> 00:29:43,360
was saved by the farmer by
<font color="

473
00:29:43,360 --> 00:29:45,680
Exactly, yeah. Another benefit -
seed dispersal, as well,

474
00:29:45,680 --> 00:29:47,880
they're really valuable
at doing that,

475
00:29:47,880 --> 00:29:49,760
and also as pollinators, too.

476
00:29:49,760 --> 00:29:53,480
Am I right in thinking that the
bat is one of the pollinators

477
00:29:53,480 --> 00:29:56,520
<font color="
which would mean...

478
00:29:56,520 --> 00:29:58,800
..no bats, no tequila?

479
00:29:58,800 --> 00:30:00,520
THEY LAUGH

480
00:30:00,520 --> 00:30:04,440
So, there's obviously a big vote
for why we should love bats.

481
00:30:06,600 --> 00:30:09,480
Perhaps the tide is turning.

482
00:30:09,480 --> 00:30:12,920
Every year, more and more
volunteers from all walks of life,

483
00:30:12,920 --> 00:30:15,520
<font color="
in protecting bats.

484
00:30:18,800 --> 00:30:21,920
Ajay went to Scotland
to discover how.

485
00:30:23,680 --> 00:30:27,080
This is Linlithgow Palace,
near Edinburgh.

486
00:30:27,080 --> 00:30:29,920
Once the residence of
Mary Queen of Scots,

487
00:30:29,920 --> 00:30:32,080
it's now home to hundreds of bats.

488
00:30:34,120 --> 00:30:37,680
<font color="
one of over 90 in the UK,

489
00:30:37,680 --> 00:30:40,280
has come to survey them.

490
00:30:40,280 --> 00:30:41,960
Amazing key, Bob.

491
00:30:41,960 --> 00:30:44,360
I can't wait to see
through this door.

492
00:30:46,680 --> 00:30:51,120
Surveys like these feed into the
National Bat Monitoring Programme,

493
00:30:51,120 --> 00:30:55,360
<font color="
which species are most at risk.

494
00:30:57,560 --> 00:31:00,160
Wow, what an incredible place.

495
00:31:01,560 --> 00:31:03,760
We're on the lookout
for a rare bat...

496
00:31:04,880 --> 00:31:06,880
..the Nathusius' pipistrelle.

497
00:31:07,960 --> 00:31:12,880
This tiny bat has been found
to fly almost 2,000km,

498
00:31:12,880 --> 00:31:15,640
<font color="

499
00:31:15,640 --> 00:31:18,800
the longest known migration
of any small mammal.

500
00:31:20,440 --> 00:31:24,280
The group here wants to find out
if there are any in the palace.

501
00:31:24,280 --> 00:31:27,480
Leading them is Natalie Todman.

502
00:31:27,480 --> 00:31:30,080
The Nathusius' pipistrelle,
we've never recorded up here

503
00:31:30,080 --> 00:31:32,320
<font color="
keen to see if we can find it.

504
00:31:32,320 --> 00:31:34,160
And that's really
quite rare, isn't it?

505
00:31:34,160 --> 00:31:37,120
It is, yes, it's probably one
of the rarest species in Britain.

506
00:31:37,120 --> 00:31:39,240
But we don't know if they're
actually roosting here,

507
00:31:39,240 --> 00:31:41,400
<font color="
to see whether we're going to

508
00:31:41,400 --> 00:31:43,200
record them here inside.

509
00:31:51,480 --> 00:31:55,760
In the Great Hall of the palace,
we spot our first bats.

510
00:31:55,760 --> 00:31:59,840
To recognise the species, we all
have detectors which can pick up

511
00:31:59,840 --> 00:32:03,040
their ultrasonic calls and
<font color="

512
00:32:04,360 --> 00:32:06,720
The frequency of the call is key.

513
00:32:09,440 --> 00:32:13,320
This one's coming through at
around about 55 kilohertz.

514
00:32:13,320 --> 00:32:15,800
And that tells us?

515
00:32:13,320 --> 00:32:15,800
THEY LAUGH

516
00:32:15,800 --> 00:32:19,600
Which tells us this this
is a bat soprano.

517
00:32:19,600 --> 00:32:23,520
<font color="
is something coming in below 40,

518
00:32:23,520 --> 00:32:26,360
which would make it a Nathusius'
pipistrelle. Absolutely.

519
00:32:26,360 --> 00:32:29,080
Oh, I just love the sound,
it's fantastic. Yeah.

520
00:32:34,200 --> 00:32:36,720
I'm sort of torn, because
<font color="

521
00:32:36,720 --> 00:32:39,280
and yet I feel like I'm missing
out on them flying above my head.

522
00:32:39,280 --> 00:32:40,800
I know, that's the problem.

523
00:32:40,800 --> 00:32:43,600
When you have a screen like this
telling you so many good things,

524
00:32:43,600 --> 00:32:46,200
it's such a temptation
to watch this when,

525
00:32:46,200 --> 00:32:48,400
<font color="
to do is watch the bats.

526
00:32:56,200 --> 00:32:59,360
The dark nooks and crannies of
the palace make it a great place

527
00:32:59,360 --> 00:33:02,200
for other species to roost.

528
00:33:02,200 --> 00:33:05,120
WHISPERING: We're looking at a
Daubenton's bat which is clinging

529
00:33:05,120 --> 00:33:07,880
to the wall, and we've got a
<font color="

530
00:33:07,880 --> 00:33:10,480
Oh, yeah, it's lovely
to see them like this.

531
00:33:10,480 --> 00:33:12,880
It feels almost like
we're intruders here,

532
00:33:12,880 --> 00:33:15,560
because we're seeing it
at such an intimate moment.

533
00:33:15,560 --> 00:33:18,000
When you see bats on the wing,
they look so powerful

534
00:33:18,000 --> 00:33:19,920
<font color="

535
00:33:19,920 --> 00:33:23,600
But when you see just how small
they are, they look very vulnerable.

536
00:33:23,600 --> 00:33:26,880
VOICEOVER: Suddenly, there's
exciting news from elsewhere.

537
00:33:26,880 --> 00:33:28,560
Ooh...!

538
00:33:28,560 --> 00:33:31,320
Natalie's got a Nathusius'.
Got a Nathusius'?

539
00:33:35,680 --> 00:33:37,960
<font color="
first Nathusius' pipistrelle

540
00:33:37,960 --> 00:33:39,160
of the evening. Fantastic!

541
00:33:39,160 --> 00:33:41,720
There's a couple up there,
there's a Nathusius'

542
00:33:41,720 --> 00:33:44,760
and there's a soprano
pipistrelle, as well. Gosh.

543
00:33:44,760 --> 00:33:47,400
<font color="
is just slightly bigger.

544
00:33:47,400 --> 00:33:51,520
A much lower frequency, coming in
just around about 40, or just under.

545
00:33:51,520 --> 00:33:54,280
It's actually really exciting to
actually find them IN the palace,

546
00:33:54,280 --> 00:33:56,200
not just around about.

547
00:34:03,600 --> 00:34:06,400
Tonight is the first time
<font color="

548
00:34:06,400 --> 00:34:08,840
has been spotted in
Linlithgow Palace.

549
00:34:11,360 --> 00:34:14,040
Did you all pick it up?
Did you get it on your detectors?

550
00:34:14,040 --> 00:34:15,960
Yes. Yes. Fantastic.

551
00:34:15,960 --> 00:34:18,160
They're putting on
a good show tonight.

552
00:34:21,680 --> 00:34:25,320
<font color="
a Nathusius' roost here,

553
00:34:25,320 --> 00:34:28,720
but this first sighting
will prompt more research.

554
00:34:30,600 --> 00:34:33,080
This is important conservation
work that feeds in to

555
00:34:33,080 --> 00:34:35,520
this national database.
Yes, that's right.

556
00:34:35,520 --> 00:34:38,600
<font color="
Programme runs various surveys

557
00:34:38,600 --> 00:34:41,440
throughout the summer,
at various levels of expertise,

558
00:34:41,440 --> 00:34:44,120
so anyone and everyone
can get involved in them.

559
00:34:44,120 --> 00:34:46,560
I've never been involved in
something like this before.

560
00:34:46,560 --> 00:34:49,000
<font color="
many different kinds of bats

561
00:34:49,000 --> 00:34:51,360
just a stone's throw from my
house, but also that we have

562
00:34:51,360 --> 00:34:54,080
rare bats here, it just makes
it all the more exciting.

563
00:35:01,600 --> 00:35:04,640
Back at Bryanston, the detectors
we've placed around the site

564
00:35:04,640 --> 00:35:07,000
<font color="
species are hunting here,

565
00:35:07,000 --> 00:35:08,920
and perhaps even roosting.

566
00:35:10,480 --> 00:35:13,920
While at the greater horseshoe
roost, our cameras are uncovering

567
00:35:13,920 --> 00:35:16,760
a fascinating and
complex social world.

568
00:35:18,040 --> 00:35:22,840
There's just a lot of activity all
<font color="

569
00:35:22,840 --> 00:35:26,560
They're grooming, and also you
can see this lovely interaction

570
00:35:26,560 --> 00:35:29,600
between those two, where
they're almost lip touching.

571
00:35:29,600 --> 00:35:33,120
I don't know whether they're
sniffing each other for recognition

572
00:35:33,120 --> 00:35:36,560
of individuals through smell,
<font color="

573
00:35:36,560 --> 00:35:39,360
So, yeah, just constant activity.

574
00:35:39,360 --> 00:35:41,600
The colony is matriarchal.

575
00:35:41,600 --> 00:35:45,280
The adults are mostly female
and often closely related -

576
00:35:45,280 --> 00:35:47,960
mothers and daughters,
aunts and nieces.

577
00:35:49,840 --> 00:35:53,880
At this time of year,
<font color="

578
00:35:55,600 --> 00:35:58,880
For the pups, the roost
is relatively safe -

579
00:35:58,880 --> 00:36:04,000
but when they fly outside tonight,
they'll encounter a raft of dangers.

580
00:36:04,000 --> 00:36:05,840
They're out for the first time.

581
00:36:05,840 --> 00:36:08,560
They don't really know,
instinctively, what's outside.

582
00:36:08,560 --> 00:36:11,000
<font color="
know this landscape

583
00:36:11,000 --> 00:36:12,760
like the back of their hands.

584
00:36:12,760 --> 00:36:15,920
But for those young bats,
they're going to have to stick with

585
00:36:15,920 --> 00:36:19,440
other colony members,
you know, just to be safe.

586
00:36:19,440 --> 00:36:21,680
For pups who do get lost or injured,

587
00:36:21,680 --> 00:36:25,040
<font color="
sometimes be a life-saver -

588
00:36:25,040 --> 00:36:27,240
as Kate's been finding out.

589
00:36:32,360 --> 00:36:35,440
I've come back to Kent to
catch up with Hazel Ryan,

590
00:36:35,440 --> 00:36:37,960
who rescues injured bats.

591
00:36:37,960 --> 00:36:41,840
We've returned to the flight cage
where the bats test their wings.

592
00:36:46,160 --> 00:36:51,000
<font color="
to Yorkletts the pipistrelle pup.

593
00:36:51,000 --> 00:36:53,920
Sadly, it didn't survive.

594
00:36:53,920 --> 00:36:56,440
Her injuries were just
too extensive from the cat

595
00:36:56,440 --> 00:36:59,560
and she didn't make it,
unfortunately. It's really sad.

596
00:36:59,560 --> 00:37:02,840
It is. And, unfortunately, you
<font color="

597
00:37:02,840 --> 00:37:05,400
because of cats. Yeah,
it must be really difficult

598
00:37:05,400 --> 00:37:08,280
when you're taking
such great care of them.

599
00:37:08,280 --> 00:37:10,920
But every one that does survive
sort of makes up for that.

600
00:37:10,920 --> 00:37:13,040
That makes the difference.
<font color="

601
00:37:13,040 --> 00:37:15,160
That's one of the bats that
I've got to flight test today,

602
00:37:15,160 --> 00:37:17,600
which I'm hoping we'll be
able to release really soon.

603
00:37:17,600 --> 00:37:20,240
You gave me Sheppey to keep warm.

604
00:37:20,240 --> 00:37:22,160
That's right. He's getting
warmed up, ready to fly!

605
00:37:22,160 --> 00:37:23,680
<font color="

606
00:37:23,680 --> 00:37:25,200
Can you feel him wriggling around?

607
00:37:25,200 --> 00:37:27,320
He's actually in here...

608
00:37:27,320 --> 00:37:28,560
..which is quite odd.

609
00:37:29,600 --> 00:37:31,880
OK, thank you.

610
00:37:31,880 --> 00:37:33,840
Aw! He's a juvenile male,

611
00:37:33,840 --> 00:37:35,920
and unfortunately he
got trapped in a house.

612
00:37:35,920 --> 00:37:38,240
<font color="
they can't fly as well,

613
00:37:38,240 --> 00:37:40,520
they get a bit confused,
and got in a house,

614
00:37:40,520 --> 00:37:42,240
and then got completely
trapped? Yeah.

615
00:37:42,240 --> 00:37:43,800
They're like all youngsters.

616
00:37:43,800 --> 00:37:46,080
They go exploring, they don't
<font color="

617
00:37:46,080 --> 00:37:48,520
Not very competent, you know,
like teenage drivers!

618
00:37:48,520 --> 00:37:50,800
But, luckily, he wasn't injured.
Oh, OK.

619
00:37:50,800 --> 00:37:52,480
He was just really starving.

620
00:37:52,480 --> 00:37:54,360
He needed rehydrating, feeding up.

621
00:37:54,360 --> 00:37:57,000
So we've been feeding him for a
<font color="

622
00:37:57,000 --> 00:37:59,280
and fat now - he's about doubled
his body weight, I think.

623
00:37:59,280 --> 00:38:00,640
That's brilliant.

624
00:38:00,640 --> 00:38:03,200
Really, today is just the
final test to make sure

625
00:38:03,200 --> 00:38:05,320
that he can be released,
hopefully, tonight.

626
00:38:05,320 --> 00:38:06,680
Oh, that's brilliant.

627
00:38:06,680 --> 00:38:08,880
<font color="
of my fingers. Oh, my goodness.

628
00:38:08,880 --> 00:38:11,080
Oh, there he goes!

629
00:38:11,080 --> 00:38:14,120
So, this is how a bat with
no injuries should be.

630
00:38:14,120 --> 00:38:17,080
You can see how fast he's flying.

631
00:38:17,080 --> 00:38:19,160
And he's coming round really fast...

632
00:38:19,160 --> 00:38:21,160
..right over our heads.
<font color="

633
00:38:21,160 --> 00:38:24,280
He's already an accomplished
flyer now, so... Wow!

634
00:38:24,280 --> 00:38:27,640
There he is. Whoa!
See, he just heads for our heads.

635
00:38:30,080 --> 00:38:31,560
That's brilliant.

636
00:38:31,560 --> 00:38:34,600
So, we're going to go and release
<font color="

637
00:38:34,600 --> 00:38:36,960
And the family are really excited,
the people who found him.

638
00:38:36,960 --> 00:38:38,400
Oh, that's brilliant.

639
00:38:38,400 --> 00:38:40,480
Are they going to be
there tonight? They are.

640
00:38:40,480 --> 00:38:43,120
They're so pleased that
<font color="

641
00:38:43,120 --> 00:38:45,720
Hi, guys. Hello! Hi!

642
00:38:45,720 --> 00:38:47,520
I heard you found a bat!

643
00:38:47,520 --> 00:38:49,040
Yes!

644
00:38:49,040 --> 00:38:52,080
My dad and my stepmum were on
holiday, and I said that I'd come

645
00:38:52,080 --> 00:38:54,600
over, put some milk in the fridge,
<font color="

646
00:38:54,600 --> 00:38:57,440
And I just looked at the sink in
the kitchen, and it was just there.

647
00:38:57,440 --> 00:38:59,360
So, how did you know who to call?

648
00:38:59,360 --> 00:39:01,920
Google.

649
00:38:59,360 --> 00:39:01,920
THEY LAUGH

650
00:39:01,920 --> 00:39:04,080
I just Googled, "What to do if
you find a bat in the house."

651
00:39:04,080 --> 00:39:06,040
<font color="
that you called? Yes.

652
00:39:06,040 --> 00:39:08,800
Yeah, National Bat Helpline. Yeah,
the Bat Conservation Trust website.

653
00:39:08,800 --> 00:39:10,240
Yeah. That's it, yeah.

654
00:39:10,240 --> 00:39:12,800
And you did all the right things -
<font color="

655
00:39:12,800 --> 00:39:14,480
making sure the lid was on tight.

656
00:39:14,480 --> 00:39:18,880
So, Jessica, I heard that you
really wanted to see this bat...

657
00:39:18,880 --> 00:39:21,280
Mm-hm. ..and you didn't
get to see it before.

658
00:39:21,280 --> 00:39:23,080
No. I've been keeping him warm.

659
00:39:23,080 --> 00:39:26,520
<font color="
have really warm wings.

660
00:39:26,520 --> 00:39:27,680
Oh.

661
00:39:27,680 --> 00:39:32,520
This is the smallest type of
bat that we have in this country.

662
00:39:32,520 --> 00:39:34,880
Oh, blimey. Yeah?

663
00:39:34,880 --> 00:39:37,560
Was it all OK? He's fine now, yeah.

664
00:39:37,560 --> 00:39:40,680
<font color="
really hungry and really thirsty.

665
00:39:40,680 --> 00:39:43,920
But now he's quite chubby cos
we've given him lots to eat.

666
00:39:43,920 --> 00:39:45,920
They look like elf ears.

667
00:39:45,920 --> 00:39:47,800
They do, don't they? Yeah.

668
00:39:47,800 --> 00:39:51,280
How do you feel about little
Sheppey being released tonight?

669
00:39:51,280 --> 00:39:54,120
<font color="
to be with its family and friends.

670
00:39:54,120 --> 00:39:56,840
Aw, that's really sweet.
Yeah, that's it.

671
00:39:56,840 --> 00:39:59,040
I think that's true.

672
00:39:59,040 --> 00:40:00,840
We've got plenty of space,

673
00:40:00,840 --> 00:40:04,080
and we can see where he goes
because he's going to, hopefully,

674
00:40:04,080 --> 00:40:05,680
<font color="

675
00:40:05,680 --> 00:40:07,640
So, it's a really good
evening to release a bat,

676
00:40:07,640 --> 00:40:09,400
cos see how calm it is here?

677
00:40:09,400 --> 00:40:11,720
Would you like to
say goodbye to him?

678
00:40:11,720 --> 00:40:13,960
Bye-bye, Sheppey.

679
00:40:15,560 --> 00:40:18,520
I wasn't sure when we found him
<font color="

680
00:40:18,520 --> 00:40:20,640
so I'm really pleased
that he's ready to go back.

681
00:40:20,640 --> 00:40:22,800
If it wasn't for you,
he wouldn't have survived.

682
00:40:22,800 --> 00:40:24,960
Well, I think if it
wasn't for you, Hazel,

683
00:40:24,960 --> 00:40:26,640
he wouldn't have survived either!

684
00:40:26,640 --> 00:40:29,960
<font color="
think, need to take credit for this.

685
00:40:29,960 --> 00:40:31,600
It's really brilliant.

686
00:40:31,600 --> 00:40:34,280
OK, he's flapping...

687
00:40:34,280 --> 00:40:35,880
Ooh, away he goes!

688
00:40:35,880 --> 00:40:38,040
He's going to circle around
a little... Where did he go?

689
00:40:38,040 --> 00:40:40,200
Oh, he went that way, off
<font color="

690
00:40:40,200 --> 00:40:44,000
Well, he didn't seem to be...
Over there, on the floor!

691
00:40:44,000 --> 00:40:46,240
No, it's on the floor.

692
00:40:48,200 --> 00:40:50,720
I thought he went that way! Yeah.

693
00:40:50,720 --> 00:40:52,480
Well done, Jessica.

694
00:40:52,480 --> 00:40:54,800
Well done! Flippin' heck.

695
00:40:57,800 --> 00:41:01,320
<font color="
we can try to release him again.

696
00:41:03,120 --> 00:41:06,720
The delay is fortunate as
another bat's shown up.

697
00:41:06,720 --> 00:41:09,200
There's a bat flying
just over there.

698
00:41:09,200 --> 00:41:10,320
That's good news.

699
00:41:15,440 --> 00:41:17,360
I think he wants to go.

700
00:41:21,080 --> 00:41:23,080
There he is, he's circling round.
<font color="

701
00:41:23,080 --> 00:41:24,880
He's with the other one,
there he is.

702
00:41:24,880 --> 00:41:27,200
He's following the other bat.
There he is.

703
00:41:27,200 --> 00:41:30,200
That's him and his friend
going round and round.

704
00:41:34,680 --> 00:41:37,800
It's really nice to see him
flying around with another one.

705
00:41:37,800 --> 00:41:39,920
<font color="
have found a better house

706
00:41:39,920 --> 00:41:41,760
to get trapped in,
actually, to be honest.

707
00:41:41,760 --> 00:41:43,360
THEY LAUGH

708
00:41:46,560 --> 00:41:48,120
There!

709
00:41:52,200 --> 00:41:54,920
Brilliant. Bye-bye, Sheppey!

710
00:42:01,720 --> 00:42:05,680
For bats, getting airborne
is only part of the challenge.

711
00:42:07,800 --> 00:42:12,440
<font color="
they have to echolocate.

712
00:42:12,440 --> 00:42:15,680
As they fly, they emit
many shrill calls.

713
00:42:15,680 --> 00:42:19,640
They're incredibly loud,
up to 140 decibels,

714
00:42:19,640 --> 00:42:22,040
noisier than a pneumatic drill.

715
00:42:23,040 --> 00:42:26,200
Yet they're so high pitched,
we can't hear them.

716
00:42:26,200 --> 00:42:28,840
<font color="

717
00:42:28,840 --> 00:42:32,360
CHIRPING CALLS

718
00:42:33,760 --> 00:42:37,480
The sound waves travel outwards,
hit objects in the environment,

719
00:42:37,480 --> 00:42:40,320
and bounce back as faint echoes.

720
00:42:40,320 --> 00:42:44,960
These allow the bat to sense
what's ahead and how far away it is,

721
00:42:44,960 --> 00:42:48,240
anything from a tree
<font color="

722
00:42:54,200 --> 00:42:58,000
Remarkably, humans can
learn to echolocate, too.

723
00:43:01,760 --> 00:43:04,640
At Durham University,
Dr Laura Thaler works with

724
00:43:04,640 --> 00:43:09,360
visually impaired people who use
echolocation to help them navigate.

725
00:43:10,880 --> 00:43:14,280
But today she's going
<font color="

726
00:43:15,520 --> 00:43:21,080
I can't really imagine that
I'm going to be able to navigate

727
00:43:21,080 --> 00:43:24,160
using sound rather
than vision today,

728
00:43:24,160 --> 00:43:28,560
but I am very much looking
forward to trying it out.

729
00:43:28,560 --> 00:43:33,360
First, Laura's going to show me
<font color="

730
00:43:33,360 --> 00:43:36,880
The goal is...that I do this
well enough so that you can

731
00:43:36,880 --> 00:43:38,960
actually hear the difference.

732
00:43:38,960 --> 00:43:41,680
Shh...!

733
00:43:41,680 --> 00:43:44,360
VOLUME INCREASES

734
00:43:44,360 --> 00:43:46,400
VOLUME DECREASES

735
00:43:46,400 --> 00:43:48,440
VOLUME INCREASES

736
00:43:49,800 --> 00:43:51,440
OK, that works. Good.

737
00:43:51,440 --> 00:43:53,760
<font color="

738
00:43:53,760 --> 00:43:56,520
But to get an echo
back that you can use,

739
00:43:56,520 --> 00:43:59,800
you need a much shorter,
sharper sound.

740
00:43:59,800 --> 00:44:01,440
A mouth click...

741
00:44:01,440 --> 00:44:03,320
SHE CLICKS MOUTH

742
00:44:03,320 --> 00:44:05,080
..is a very brief sound.

743
00:44:05,080 --> 00:44:06,640
LUCY CLICKS MOUTH

744
00:44:06,640 --> 00:44:08,560
<font color="

745
00:44:08,560 --> 00:44:10,600
SHE CLICKS

746
00:44:10,600 --> 00:44:13,920
Now I'll try to use
my clicks to help me find

747
00:44:13,920 --> 00:44:17,240
the edges of an obstacle
while I'm blindfolded.

748
00:44:18,360 --> 00:44:23,760
What I would like you to do
is click and move sidewards,

749
00:44:23,760 --> 00:44:27,400
<font color="
sound feedback to determine

750
00:44:27,400 --> 00:44:29,480
once you've passed the obstacle.

751
00:44:29,480 --> 00:44:33,240
So, you want me to walk sideways
like a crab whilst clicking...?

752
00:44:33,240 --> 00:44:34,920
Yes.

753
00:44:34,920 --> 00:44:39,600
..to see if I can judge
where the obstacle is?

754
00:44:39,600 --> 00:44:41,640
Yes, yes.

755
00:44:41,640 --> 00:44:47,280
<font color="

756
00:44:48,640 --> 00:44:52,240
I got it right! I thought that's
where the change was! Brilliant.

757
00:44:54,200 --> 00:44:58,240
Someone who's taken part in
Laura's research is Kerrie Brown.

758
00:45:00,720 --> 00:45:03,840
She lost her sight to
eye cancer as a child,

759
00:45:03,840 --> 00:45:07,800
and is one of an estimated
<font color="

760
00:45:07,800 --> 00:45:10,640
who've learned to use
a form of echolocation.

761
00:45:10,640 --> 00:45:12,560
Bye! Bye!

762
00:45:12,560 --> 00:45:14,520
KERRIE CLICKS MOUTH

763
00:45:14,520 --> 00:45:16,480
Just doing that just now,
I can definitely pick up

764
00:45:16,480 --> 00:45:18,200
a hedge there, or a tree.

765
00:45:18,200 --> 00:45:21,640
<font color="
bouncing back from a solid object.

766
00:45:21,640 --> 00:45:23,880
It's quite open here at the moment.

767
00:45:23,880 --> 00:45:27,560
She uses her stick to warn her
what's on the ground just ahead,

768
00:45:27,560 --> 00:45:32,080
and echolocation for obstacles
in the wider environment.

769
00:45:32,080 --> 00:45:33,880
KERRIE CLICKS

770
00:45:33,880 --> 00:45:36,200
<font color="
which is probably a pole,

771
00:45:36,200 --> 00:45:39,280
cos it's a good sharp sound that
comes from it but it's quite thin.

772
00:45:39,280 --> 00:45:41,680
Obviously, you don't get
the echo for very long.

773
00:45:41,680 --> 00:45:43,480
A car would be longer and lower,

774
00:45:43,480 --> 00:45:46,040
so you can start
<font color="

775
00:45:47,120 --> 00:45:49,920
If I really want to hone in
on something and I need to be

776
00:45:49,920 --> 00:45:52,000
quite accurate, I'll start
doing faster clicks.

777
00:45:52,000 --> 00:45:53,880
KERRIE CLICKS FASTER

778
00:45:53,880 --> 00:45:56,800
And that lamppost there is a
good one that I've hit before

779
00:45:56,800 --> 00:45:59,160
<font color="
on echolocation.

780
00:45:59,160 --> 00:46:01,840
So it's a good one to try and
hone in on with the clicks.

781
00:46:06,160 --> 00:46:09,240
Back at the research lab,
Laura is exploring how

782
00:46:09,240 --> 00:46:13,520
echolocation compares to vision
as a means of navigating.

783
00:46:15,760 --> 00:46:19,400
<font color="
motion capture technology.

784
00:46:20,760 --> 00:46:22,720
So, Lucy, move your feet.

785
00:46:23,760 --> 00:46:26,840
Move your shoulders.
Yep, there you go.

786
00:46:26,840 --> 00:46:29,600
That's you. Yeah...!

787
00:46:29,600 --> 00:46:31,920
That is really cool!

788
00:46:31,920 --> 00:46:35,720
I have to navigate round
<font color="

789
00:46:35,720 --> 00:46:38,840
First, using echolocation...

790
00:46:38,840 --> 00:46:41,280
..then with my eyes open.

791
00:46:44,240 --> 00:46:49,440
Laura is now going to show me how
my attempts compare with Kerrie's.

792
00:46:49,440 --> 00:46:52,400
Kerrie did the same task as you did.

793
00:46:53,960 --> 00:46:56,200
She actually...

794
00:46:56,200 --> 00:46:58,600
..walks quite fast.

795
00:46:58,600 --> 00:47:00,280
<font color="

796
00:47:00,280 --> 00:47:03,680
She walks really fast
and really confidently. Yes.

797
00:47:03,680 --> 00:47:06,280
And not doing the same sort
of shuffling and dithering

798
00:47:06,280 --> 00:47:08,000
that I did. No.

799
00:47:08,000 --> 00:47:10,520
Compared to when you walked
with your eyes open, though,

800
00:47:10,520 --> 00:47:14,760
<font color="
the obstacle is a bit later.

801
00:47:14,760 --> 00:47:18,720
But in terms of, you know,
how swiftly she actually moves...

802
00:47:20,320 --> 00:47:22,040
..you know, we couldn't really tell.

803
00:47:22,040 --> 00:47:23,600
Seriously impressive.

804
00:47:24,920 --> 00:47:27,840
Laura's been investigating
what it is that makes people

805
00:47:27,840 --> 00:47:29,960
<font color="

806
00:47:31,360 --> 00:47:35,280
So, effectively, these people
are using echolocation to see.

807
00:47:35,280 --> 00:47:37,640
What's happening in the brain?

808
00:47:37,640 --> 00:47:40,760
So, one thing we have done
to get at this question is,

809
00:47:40,760 --> 00:47:43,360
is to put people
into an MRI scanner.

810
00:47:43,360 --> 00:47:47,280
<font color="
are trained in echolocation,

811
00:47:47,280 --> 00:47:52,440
they process echolocation sounds
in a part that we refer to

812
00:47:52,440 --> 00:47:54,600
as primary visual cortex.

813
00:47:54,600 --> 00:47:56,960
So, it's the part of
the brain that receives

814
00:47:56,960 --> 00:47:59,080
direct input from the retinas.

815
00:47:59,080 --> 00:48:03,800
<font color="
who are using echolocation

816
00:48:03,800 --> 00:48:06,920
are using their visual cortex
in the same way that people

817
00:48:06,920 --> 00:48:09,880
who have sight use to navigate?

818
00:48:09,880 --> 00:48:11,400
So they... Or a similar way?

819
00:48:11,400 --> 00:48:12,760
Yes, yeah.

820
00:48:12,760 --> 00:48:15,680
That has blown my mind.

821
00:48:19,240 --> 00:48:23,240
<font color="
Kerrie has experienced.

822
00:48:23,240 --> 00:48:26,200
When I was doing my training,
I had a bit of an "Ah-ha" moment,

823
00:48:26,200 --> 00:48:29,080
which was when I echolocated
a flight of steps going up.

824
00:48:29,080 --> 00:48:32,720
I felt like I saw the graduation of
the steps going up in front of me.

825
00:48:32,720 --> 00:48:36,160
<font color="
something like that happens.

826
00:48:36,160 --> 00:48:38,760
What's interesting for me
is how far I can push myself

827
00:48:38,760 --> 00:48:41,720
and how much I can do that
I didn't think was possible.

828
00:48:43,040 --> 00:48:47,840
Echolocation is a relatively
new and rare skill for humans...

829
00:48:47,840 --> 00:48:51,720
<font color="
50 million years to perfect it.

830
00:48:54,560 --> 00:48:57,960
Their mastery is most
apparent when they hunt.

831
00:48:59,920 --> 00:49:02,720
This pipistrelle,
in total darkness,

832
00:49:02,720 --> 00:49:07,760
is honing in on a tiny midge
just a millimetre long.

833
00:49:07,760 --> 00:49:11,080
Returning echoes allow
<font color="

834
00:49:11,080 --> 00:49:15,200
and within a tenth of a second,
the midge is doomed.

835
00:49:18,960 --> 00:49:23,320
Back at Bryanston, our pups
are just learning to echolocate.

836
00:49:23,320 --> 00:49:26,480
Most bats make these calls
through their mouth,

837
00:49:26,480 --> 00:49:29,600
but the horseshoes
<font color="

838
00:49:30,760 --> 00:49:34,040
The horseshoe-shaped folds
of skin act as a megaphone

839
00:49:34,040 --> 00:49:37,600
to boost the sound and
give this bat its name.

840
00:49:39,240 --> 00:49:44,520
But our pups' echolocation isn't yet
good enough to hunt down insects.

841
00:49:45,600 --> 00:49:47,040
For the next few weeks,

842
00:49:47,040 --> 00:49:49,520
<font color="
on their mother's milk.

843
00:49:51,480 --> 00:49:55,360
Here, a large pup is suckling.

844
00:49:56,720 --> 00:49:59,440
I've read that the
lactating mothers,

845
00:49:59,440 --> 00:50:04,040
they'll eat their lean body
mass every night in insects.

846
00:50:04,040 --> 00:50:06,600
Yeah, I mean,
the thing is that they...

847
00:50:06,600 --> 00:50:12,160
<font color="
of energy, the gestation period,

848
00:50:12,160 --> 00:50:16,160
and then producing the milk,
and making sure that those pups

849
00:50:16,160 --> 00:50:18,440
are well fed and grow quickly.

850
00:50:18,440 --> 00:50:21,600
So they really have to
either take very large prey,

851
00:50:21,600 --> 00:50:25,520
or consume, you know,
<font color="

852
00:50:25,520 --> 00:50:30,360
to be able to produce
the milk for the pups.

853
00:50:32,720 --> 00:50:36,000
At the greater horseshoe roost,
it's the moment we've been

854
00:50:36,000 --> 00:50:39,680
waiting for - the maiden flight
of many of the young pups.

855
00:50:40,840 --> 00:50:43,880
First, they'll leave the
<font color="

856
00:50:45,640 --> 00:50:49,920
Then, fly down into a large semi
open space on the ground floor

857
00:50:49,920 --> 00:50:52,440
for some final flight practice.

858
00:50:53,760 --> 00:50:56,680
I'm going inside with
specialist cameraman

859
00:50:56,680 --> 00:50:59,080
and bat enthusiast Ian Baker.

860
00:51:00,600 --> 00:51:03,320
Fantastic.
<font color="

861
00:51:03,320 --> 00:51:05,360
Get that camera on.

862
00:51:06,960 --> 00:51:10,600
And would you expect to see bats
flying around now, Ian?

863
00:51:10,600 --> 00:51:13,920
Probably another five minutes.
Five minutes to go?

864
00:51:13,920 --> 00:51:16,600
We've cut it a bit fine,
but we're in position.

865
00:51:19,840 --> 00:51:22,360
<font color="

866
00:51:25,680 --> 00:51:28,840
This is the perfect place for
us to observe the bats up close

867
00:51:28,840 --> 00:51:31,320
before they leave the building.

868
00:51:31,320 --> 00:51:33,600
BATS CHIRP

869
00:51:35,480 --> 00:51:39,480
There seems to be little
family groups that rotate

870
00:51:39,480 --> 00:51:42,720
and circulate around and
<font color="

871
00:51:42,720 --> 00:51:46,160
This behaviour we can study
in great detail now,

872
00:51:46,160 --> 00:51:49,000
and see things that
we've never seen before.

873
00:51:50,240 --> 00:51:51,560
Do you think that was a pup?

874
00:51:51,560 --> 00:51:53,680
Yes. It looks like
there's a piece of string

875
00:51:53,680 --> 00:51:55,880
between the mum and the pup.

876
00:51:55,880 --> 00:51:59,120
<font color="
in close formation,

877
00:51:59,120 --> 00:52:01,520
and the leading bat
looks slightly larger.

878
00:52:02,680 --> 00:52:06,720
This must be a mother
teaching her pup how to fly.

879
00:52:09,520 --> 00:52:12,360
Some pups are still
very much learners.

880
00:52:12,360 --> 00:52:15,960
Here, two young bats
<font color="

881
00:52:17,720 --> 00:52:19,920
Some bats refuse to come
out when they're told to

882
00:52:19,920 --> 00:52:21,520
and just hang at the exit.

883
00:52:21,520 --> 00:52:26,080
Rebellious teenagers.
Rebellious teenagers!

884
00:52:26,080 --> 00:52:28,760
There's a lot of stuff
for them to learn. Yeah.

885
00:52:28,760 --> 00:52:31,800
<font color="
spatial memory.

886
00:52:31,800 --> 00:52:34,880
And where to get the food.
I mean, it's like their brain cells

887
00:52:34,880 --> 00:52:37,760
are just firing and just growing.
It's just amazing, isn't it? Yeah.

888
00:52:37,760 --> 00:52:41,840
To think of, kind of, what's
going on with these pups now.

889
00:52:45,960 --> 00:52:49,120
<font color="
and Ajay are setting up

890
00:52:49,120 --> 00:52:53,520
with detectors and clickers,
ready to count the bats.

891
00:52:57,360 --> 00:52:59,160
Ooh...! Oh! Ah!

892
00:52:59,160 --> 00:53:01,880
We just had one fly out
and fly straight back in.

893
00:53:01,880 --> 00:53:04,760
There'll be quite
<font color="

894
00:53:04,760 --> 00:53:07,640
Oh, there's one...

895
00:53:07,640 --> 00:53:09,040
There we go.

896
00:53:11,800 --> 00:53:14,120
Uh, this is quite stressful.

897
00:53:14,120 --> 00:53:15,560
This is amazing!

898
00:53:16,960 --> 00:53:20,720
So, this is one of the first times
that their babies are flying.

899
00:53:20,720 --> 00:53:22,760
Whoa! Oh, my goodness.

900
00:53:24,640 --> 00:53:27,960
<font color="
bit scared by being left,

901
00:53:27,960 --> 00:53:31,320
and then they're trying their
best to follow their mums out?

902
00:53:31,320 --> 00:53:35,240
We can make assumptions if we see
pairs of bats emerging together

903
00:53:35,240 --> 00:53:39,880
and one of them appears to be
a larger, more competent flyer.

904
00:53:39,880 --> 00:53:43,000
<font color="
Oh, hey! Hey.

905
00:53:43,000 --> 00:53:45,840
How many do you think have
come out? Over 100, so far.

906
00:53:45,840 --> 00:53:47,640
Over 100, yeah, wow. OK.

907
00:53:47,640 --> 00:53:51,600
I just think it's such a thrilling
thing to think that some of these

908
00:53:51,600 --> 00:53:53,360
<font color="

909
00:53:54,760 --> 00:53:58,760
Close to the roost, badgers,
owls and foxes are on the hunt

910
00:53:58,760 --> 00:54:04,400
for an easy meal, so it's crucial
the pups don't crash land.

911
00:54:04,400 --> 00:54:07,520
I just saw one come out
and just circle around,

912
00:54:07,520 --> 00:54:10,360
so that could be a
<font color="

913
00:54:10,360 --> 00:54:13,840
Could be...! Could be,
could be, could be...!

914
00:54:13,840 --> 00:54:18,280
A tree next to the building
seems a favourite training ground.

915
00:54:18,280 --> 00:54:21,840
Mothers and pups
circle it continuously.

916
00:54:21,840 --> 00:54:23,440
They're doing practice flights.

917
00:54:23,440 --> 00:54:25,720
<font color="
flying around the building,

918
00:54:25,720 --> 00:54:29,520
flying around these trees,
just in amongst the vegetation.

919
00:54:29,520 --> 00:54:33,320
That bat there keeps doing
circles around the tree,

920
00:54:33,320 --> 00:54:36,880
and then goes off that way.
Maybe it's going back in again.

921
00:54:36,880 --> 00:54:40,400
<font color="
for me today to be here,

922
00:54:40,400 --> 00:54:44,600
to see all of these bats sort
of flooding out of this building.

923
00:54:44,600 --> 00:54:48,400
You know, we live at a
time with insect apocalypse

924
00:54:48,400 --> 00:54:51,120
and environmental degradation,
and it's such doom and gloom.

925
00:54:51,120 --> 00:54:54,440
<font color="
just lifts your spirits.

926
00:54:56,520 --> 00:54:59,440
Before long, it's all quiet again.

927
00:54:59,440 --> 00:55:02,880
The outpouring of bats
is over for tonight.

928
00:55:04,880 --> 00:55:07,080
It was quite frenetic
there for a while.

929
00:55:07,080 --> 00:55:10,400
It was fast, it was exciting.

930
00:55:10,400 --> 00:55:14,240
<font color="
but it is, I think it's the end.

931
00:55:14,240 --> 00:55:15,640
So, that's their first flight!

932
00:55:15,640 --> 00:55:18,640
Wahey! Brilliant. I don't
think they did too badly.

933
00:55:18,640 --> 00:55:21,920
None of them crashed into us, so...
<font color="

934
00:55:21,920 --> 00:55:25,440
We've seen pups coming out
and flexing their wings

935
00:55:25,440 --> 00:55:28,200
and experimenting with
flying in this space.

936
00:55:28,200 --> 00:55:30,440
It's just totally
thrilling, isn't it?

937
00:55:30,440 --> 00:55:35,360
Yeah. It's a real privilege,
<font color="

938
00:55:37,560 --> 00:55:40,560
Now the numbers have been gathered
from our count here at the roost,

939
00:55:40,560 --> 00:55:43,960
and from the detectors that
will tell us about other bats

940
00:55:43,960 --> 00:55:47,400
around Bryanston, it's
time to find out the results.

941
00:55:49,400 --> 00:55:53,640
First, the all important census
<font color="

942
00:55:55,080 --> 00:55:58,800
The final count was around 400 bats.

943
00:55:58,800 --> 00:56:00,760
So well done on the clickers.

944
00:56:00,760 --> 00:56:02,760
Yay! Very good.

945
00:56:02,760 --> 00:56:06,040
And I think that feels
like a positive result.

946
00:56:06,040 --> 00:56:11,240
Yeah, it shows that the colony
is continuing to increase here.

947
00:56:11,240 --> 00:56:15,400
<font color="
it's literally tripled in size

948
00:56:15,400 --> 00:56:18,400
in terms of the adult bats in there.

949
00:56:18,400 --> 00:56:22,760
That's around about 100 of this
year's young that are already

950
00:56:22,760 --> 00:56:25,120
leaving the roost in the evening,

951
00:56:25,120 --> 00:56:27,920
which is really exciting
to have observed that.

952
00:56:27,920 --> 00:56:32,480
<font color="
what's happening, nationally.

953
00:56:32,480 --> 00:56:36,000
We're starting to see greater
horseshoe bats make a comeback,

954
00:56:36,000 --> 00:56:38,200
but it's really important
to remember that that's

955
00:56:38,200 --> 00:56:41,320
against a backdrop of a
massive historical decline.

956
00:56:41,320 --> 00:56:44,000
<font color="
not out of the woods.

957
00:56:44,000 --> 00:56:47,720
Absolutely. But I can't help
feel a little bit inspired

958
00:56:47,720 --> 00:56:50,840
by the work that you've done here,
because that is just a sort of

959
00:56:50,840 --> 00:56:54,400
tremendous result, to feel that
you're having this success here,

960
00:56:54,400 --> 00:56:56,920
<font color="
some hope from it, for sure.

961
00:56:58,560 --> 00:57:01,240
Kate's got some interesting
news, too, from the detectors

962
00:57:01,240 --> 00:57:04,200
we placed by the river
and the clock tower.

963
00:57:04,200 --> 00:57:07,280
We processed all the data
from the AudioMoths,

964
00:57:07,280 --> 00:57:10,120
<font color="
was about 12 species,

965
00:57:10,120 --> 00:57:12,560
and up by the clock
tower there's about ten.

966
00:57:12,560 --> 00:57:14,680
So, you've got a really
great population here

967
00:57:14,680 --> 00:57:16,360
of different species.

968
00:57:16,360 --> 00:57:19,240
Actually, one of the interesting
things is that there are

969
00:57:19,240 --> 00:57:21,760
<font color="
around the clock tower.

970
00:57:21,760 --> 00:57:24,040
There was a huge kind of dawn swarm.

971
00:57:24,040 --> 00:57:27,240
So, that's where they're all
circling around their roost

972
00:57:27,240 --> 00:57:30,720
before they go back in
and rest up for the day.

973
00:57:30,720 --> 00:57:34,680
So, I think that, you know,
<font color="

974
00:57:34,680 --> 00:57:38,080
with a bat soprano
roost, in the clock tower,

975
00:57:38,080 --> 00:57:41,600
because of the timing of the
activity that we're seeing.

976
00:57:41,600 --> 00:57:45,800
Anita, what was it like seeing
inside the roost with the cameras?

977
00:57:45,800 --> 00:57:48,440
Having the opportunity to
<font color="

978
00:57:48,440 --> 00:57:51,640
that you've not seen before,
that's new to you,

979
00:57:51,640 --> 00:57:54,560
despite the fact that you've
been working around these animals

980
00:57:54,560 --> 00:57:57,520
for a long time -
it's been brilliant.

981
00:57:57,520 --> 00:58:00,480
And as the technology becomes
<font color="

982
00:58:00,480 --> 00:58:03,320
more and more people can get
involved and contribute data,

983
00:58:03,320 --> 00:58:05,760
and it just becomes
exponential, doesn't it?

984
00:58:05,760 --> 00:58:08,040
We're going to learn
a lot more about bats

985
00:58:08,040 --> 00:58:10,120
in the next few years,
<font color="

986
00:58:10,120 --> 00:58:13,680
It's going to be the glory years,
hopefully, for the bat.

987
00:58:13,680 --> 00:58:15,440
Let's hope.