very quiet we're about to savour the sound of silence
to understand how silent can be deadly first of all you have to see it in action to anyone
who might ask how you can see silence all you need is an amazing microphone like this so if i create
over the top of this microphone the sound that a normal bird's wing beats would make this happens
what do you think of that what's this silly man doing
and if we now look at how that sound has reproduced
here you can see a neat waveform and if we play it back
any normal bird flies over the top of these microphones and we will hear it
but what happens when the barn owl does it
lilly's handler rose gets her ready she's been trained to fly towards the lure i'm holding
very quiet we're about to savor the sound of silence
i simply didn't hear her coming
well that was truly extraordinary and i can say for absolute certain if i was
a vole down in the undergrowth there's no way i would have heard lily coming but
let's see if technology tells a different story
let's listen
that's ridiculous total silence nothing
i am so embarrassing
yeah officially the only sound on this is me
the bird has flown over the top of those microphones
absolutely nothing and how does it manage that it's all about the owl's unique flight feathers
running down the leading edge is almost like a comb this is completely different to what
you'd see in most bird of prey feathers it breaks up the movement of wind over the wing
and it creates this micro turbulence which is effectively silent
and for one final test let's see lily find her prey in complete darkness turning our camera to owl vision
will be able to test her legendary ability to find prey in the dark this little gadget this bleeper
our barn owl has been trained to target so i'm going to hide it in one of these bushes around
here and hopefully she'll hover and then pounce and we should get to see this whole spectacle
in a way that no human being ever normally would because it's just too dark so in it goes
let's let the owl loose
lily is using her impeccable hearing and night vision to detect the beeper
way to go lily bullseye and i still didn't hear her coming
when a barn owl's hunting it really is a silent night
truly a deadly predator