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What_s it like to be a bat_ How do they see the world_(M4A_128K) · Luke's English Podcast

• 0:07
  Speaker 1: Hi everyone, welcome to this episode of Science of the Times.
• 0:10
  Speaker 1: I'm Simon Khalid.
• 0:11
  Speaker 2: And I'm Tim Colson.
• 0:13
  Speaker 1: So how are you doing, Tim?
• 0:15
  Speaker 2: Yeah, not too bad, not too bad at all. How
• 0:17
  Speaker 2: about you? I mean, kind of autumn's now here, isn't it?
• 0:20
  Speaker 3: You know, summer's sort of a distant memory, but hopefully
• 0:23
  Speaker 3: we'll still get a few more sunny days.
• 0:25
  Speaker 1: Yeah, I think so, hopefully. But really looking forward to
• 0:30
  Speaker 1: today's podcast episode.
• 0:33
  Speaker 3: It's all about bats. And I mean, you're a bit batty.
• 0:35
  Speaker 3: So presumably that's why you're so excited by it.
• 0:39
  Speaker 1: That was so low. I was thinking he won't do it.
• 0:42
  Speaker 1: He won't go there. But of course you did. And
• 0:44
  Speaker 1: I suppose you consider yourself to be the bat man.
• 0:48
  Speaker 3: Well, actually, I think the person we're interviewing is really
• 0:51
  Speaker 3: the bat man. I mean, it's super knowledgeable about bats.
• 0:55
  Speaker 3: He kind of does a mix of how bats sense
• 0:58
  Speaker 3: the environment as they're flying around. And, you know, there's
• 1:02
  Speaker 3: I think about 1,500 bat.
• 1:04
  Speaker 2: Species out there.
• 1:05
  Speaker 3: And, you know, they can see, but they also use
• 1:09
  Speaker 3: this clicking, this echolocation to paint images of where they're going.
• 1:12
  Speaker 2: So I'm sure we'll learn lots about that.
• 1:15
  Speaker 1: Yeah, really, really looking forward to it, actually. I mean,
• 1:17
  Speaker 1: I'd say bats are sort of universally popular, aren't they?
• 1:20
  Speaker 1: And I think it's something humans have, well, I don't
• 1:23
  Speaker 1: know how to say always, it makes me sound like
• 1:25
  Speaker 1: a Methuselah or something, but certainly as long as I
• 1:27
  Speaker 1: feel alive and, you know, sort of humans have had
• 1:31
  Speaker 1: a fascinating interest in bats. So yeah, shall we get
• 1:34
  Speaker 1: him on?
• 1:34
  Speaker 2: Let's get him on. Yeah, excellent.
• 1:37
  Speaker 3: So it's an absolute delight to have Yossi Yovel on
• 1:42
  Speaker 3: the line, who's authored a book that's just come out,
• 1:47
  Speaker 3: The Genius Bat, It has a slightly different title, I believe, Yossi,
• 1:51
  Speaker 3: subtitle Yossi in the US. But perhaps you could introduce yourself,
• 1:56
  Speaker 3: first of all, and then tell us about the US title, perhaps.
• 2:00
  Speaker 4: Sure.
• 2:00
  Speaker 5: So, first of all, thanks for inviting me, Tim and Saima.
• 2:04
  Speaker 5: I'm Yossi Ovel. I'm a scientist in Tel Aviv University.
• 2:08
  Speaker 5: I like to say that I'm a neuroecologist, which is
• 2:11
  Speaker 5: a strange title. This means that I'm somewhere in between
• 2:15
  Speaker 5: neuroscience and ecology. I think these are two huge fields
• 2:18
  Speaker 5: of science that usually do not communicate with each other
• 2:22
  Speaker 5: too much. And I think they should, because basically they're
• 2:25
  Speaker 5: looking at two sides of the same coin, right?
• 2:28
  Speaker 4: On the one hand, ecologists are.
• 2:30
  Speaker 5: Looking at the interactions between animals and their environment.
• 2:33
  Speaker 4: Maybe we could say something like this very, very generally.
• 2:36
  Speaker 5: On the other hand, neuroscientists are trying to understand how
• 2:39
  Speaker 5: the brain operates, organisms, behavior. At least those are the
• 2:44
  Speaker 5: parts of neuroscience that I'm interested in. I'm trying to
• 2:47
  Speaker 5: somehow attend conferences in both fields and somehow help to
• 2:53
  Speaker 5: bridge this gap.
• 2:54
  Speaker 4: I don't want to say I'm bridging this gap. That's
• 2:55
  Speaker 4: too much to say.
• 2:57
  Speaker 2: Okay. But you're in Canada at the moment, I think.
• 3:01
  Speaker 2: Is that right?
• 3:02
  Speaker 5: Yeah, I'm on sabbatical in Canada and I'm affiliated with
• 3:06
  Speaker 5: McGill University.
• 3:07
  Speaker 4: I joined sabbatical.
• 3:11
  Speaker 3: But you've already written a book. I thought sabbaticals for
• 3:13
  Speaker 3: write a book or are you writing another one?
• 3:16
  Speaker 5: Yeah, I'm trying to write another one. I usually write
• 3:19
  Speaker 5: five in the morning, 5 a.m. Those are my hours
• 3:22
  Speaker 5: of writing.
• 3:23
  Speaker 4: I try to write like an hour every day before
• 3:25
  Speaker 4: the day begins.
• 3:27
  Speaker 5: I'm trying to write something that is a little bit
• 3:29
  Speaker 5: more general about animal sociality in general. I mean, there've
• 3:32
  Speaker 5: been quite a few books already, good ones, but I'm
• 3:35
  Speaker 5: trying to give it a different angle. And as you've
• 3:38
  Speaker 5: seen with the previous book, I also include a lot
• 3:40
  Speaker 5: of my personal experiences. So Out of the things that
• 3:43
  Speaker 5: I'm doing now, which I really love, and being here
• 3:47
  Speaker 5: in North America.
• 3:47
  Speaker 4: Is a huge advantage.
• 3:49
  Speaker 5: I go to visit other researchers who do work in
• 3:53
  Speaker 5: the tropics, Central America, South America.
• 3:56
  Speaker 4: I join them in the field. For me, first of all.
• 3:58
  Speaker 5: It's amazing always to see how other people work. And
• 4:01
  Speaker 5: the fact that I'm here makes it much easier for me.
• 4:03
  Speaker 5: So that's going. Hopefully, all of this will go into
• 4:06
  Speaker 5: maybe a second book.
• 4:09
  Speaker 1: I must say your working practices also reflect Tim's he
• 4:13
  Speaker 1: also gets up at 5am to start writing don't you Tim?
• 4:16
  Speaker 3: I do but normally I go to the pool at
• 4:18
  Speaker 3: 6 or swim.
• 4:23
  Speaker 5: I have three kids the youngest is still 2 years
• 4:25
  Speaker 5: old so no pool for me at those hours.
• 4:28
  Speaker 3: You don't know but with young kids you get enough
• 4:30
  Speaker 3: exercise as it is I think so I wonder if
• 4:34
  Speaker 3: we so I'll kick off Simon then you can ask
• 4:36
  Speaker 3: the next one so you know, you're well known, Yossi,
• 4:40
  Speaker 3: for your work, particularly on bats. And, you know, that's
• 4:44
  Speaker 3: what your first book is about. And you've done some,
• 4:47
  Speaker 3: you know, really groundbreaking research on kind of bat sonar, biosonar.
• 4:54
  Speaker 3: You know, what would you say the most kind of
• 4:55
  Speaker 3: surprising thing that you've learned about bats as you've been
• 5:00
  Speaker 3: doing this work?
• 5:01
  Speaker 2: I mean, you call your book The Genius Bat.
• 5:03
  Speaker 3: So, you know, it's packed with facts from Vampire bats
• 5:07
  Speaker 3: from tiny little hummingbee bats, you know, right the way
• 5:10
  Speaker 3: through to flying foxes and what have you. There must
• 5:14
  Speaker 3: be one or two things that have just blown your mind.
• 5:16
  Speaker 2: Yeah.
• 5:19
  Speaker 5: Well, you know, I don't want to disappoint you, but
• 5:21
  Speaker 5: I always say science is not a surprise party. I mean,
• 5:25
  Speaker 5: a lot of what we do, I think, is to
• 5:26
  Speaker 5: try to confirm hypotheses that have always been there or
• 5:30
  Speaker 5: questions that have always been there. And, you know, if
• 5:32
  Speaker 5: the result is really surprising, we should sometimes check our
• 5:36
  Speaker 5: results again.
• 5:36
  Speaker 4: I think, you know, people.
• 5:38
  Speaker 5: tend to think everything has to be really a surprise,
• 5:41
  Speaker 5: at least when I talk to people who are not scientists.
• 5:43
  Speaker 4: And I think we should be careful.
• 5:45
  Speaker 5: Surprising results are usually we should be careful with. But
• 5:49
  Speaker 5: I want to tell you about the recent result, which
• 5:52
  Speaker 5: I think is mind blowing, even though it's been an
• 5:55
  Speaker 5: hypothesis since ever. So since I became interested in bat echolocation,
• 6:02
  Speaker 5: which is somewhere around 2002, 2003, I went to do
• 6:06
  Speaker 5: my PhD in Germany in Tübingen.
• 6:08
  Speaker 4: And one of the main questions was, OK, bats can
• 6:11
  Speaker 4: use sonar, right? Of course, right?
• 6:13
  Speaker 5: That's what they do. But echolocating bats. By the way,
• 6:16
  Speaker 5: all bats can see. We should say this. Sometimes people
• 6:19
  Speaker 5: don't know this. But bats can also use vision. And
• 6:23
  Speaker 5: people have mostly studied echolocation indoors, right? We place a
• 6:26
  Speaker 5: bat in a room and we train it to do
• 6:29
  Speaker 5: some tasks or we just observe its behavior. And people
• 6:32
  Speaker 5: have shown that bats have remarkable spatial orientation in these
• 6:35
  Speaker 5: small confined environments. So for example, people have shown Cindy
• 6:39
  Speaker 5: Moss from Maryland University at the time showed that bats
• 6:43
  Speaker 5: can return to the same exact spot in the room
• 6:46
  Speaker 5: on a mesh or on a wall, remembering acoustically because
• 6:51
  Speaker 5: it's all in complete darkness, remembering the structure and position
• 6:54
  Speaker 5: of the room with accuracy of centimeters maybe. But, but
• 6:58
  Speaker 5: for me, yeah, that's amazing. But for me, the question was,
• 7:01
  Speaker 5: and you know, if you're asking me about amazing results,
• 7:03
  Speaker 5: you know, some of the most amazing results are already
• 7:06
  Speaker 5: have been already found 50 years ago, showing that bats
• 7:08
  Speaker 5: can can range can compute or estimate the accuracy of
• 7:11
  Speaker 5: distance of objects with a with an accuracy of less
• 7:16
  Speaker 5: than one millimeter. So when they're intercepting prey, for example,
• 7:19
  Speaker 5: they know probably where this prey is within less than
• 7:23
  Speaker 5: a millimeter of error. And this has been found by
• 7:27
  Speaker 5: giants like Schnitzler, Uli Schnitzler, and Jim Simmons, who are
• 7:30
  Speaker 5: all interviewed and mentioned in the book. But sorry, let's
• 7:33
  Speaker 5: go back to my own. Yeah, I will drift a
• 7:37
  Speaker 5: lot probably during this talk. this interview, but so one
• 7:42
  Speaker 5: of the main questions for me as a student was,
• 7:44
  Speaker 5: and I believe for others too, you know, okay, they
• 7:46
  Speaker 5: can use echolocation, sonar, sound, but can they use it outdoors?
• 7:52
  Speaker 5: Can they also navigate many kilometers with this? And, you know,
• 7:56
  Speaker 5: people write things based on observations, which are very limited.
• 8:00
  Speaker 5: You know, I'm not trying to reduce the results of anyone,
• 8:04
  Speaker 5: but that's.
• 8:05
  Speaker 4: What we could do.
• 8:06
  Speaker 5: Because what people could do for many, many years is
• 8:08
  Speaker 5: observe bats in the field with binoculars or thermal cameras
• 8:12
  Speaker 5: or maybe microphones. And we can only see them for
• 8:14
  Speaker 5: these very brief instances when they go back. And then
• 8:18
  Speaker 5: we can say, OK, we see them going near trees.
• 8:21
  Speaker 5: So maybe they're using the tree.
• 8:22
  Speaker 4: Is to navigate, right?
• 8:23
  Speaker 5: But we couldn't really observe the same individual over.
• 8:27
  Speaker 4: Very long periods of time.
• 8:29
  Speaker 5: And one of the things that we've done, and today
• 8:31
  Speaker 5: others are also doing this, is to develop very small
• 8:33
  Speaker 5: sensors that include the GPS devices and microphones, which can
• 8:37
  Speaker 5: be mounted on the bats. and allow us now to
• 8:42
  Speaker 5: track the same individual bat. By the way, the main
• 8:45
  Speaker 5: challenge was that the bats are small, very small, usually 20,
• 8:48
  Speaker 5: 30 grams. So we had to have very, very small
• 8:50
  Speaker 5: miniature devices. And these now allow us to observe the
• 8:54
  Speaker 5: same individual bat over a complete night, full nights. Okay,
• 8:58
  Speaker 5: so maybe one of the most exciting events in my
• 9:01
  Speaker 5: scientific career was somewhere 2012, I think, or 11, no,
• 9:06
  Speaker 5: probably 12. We were sitting, we just managed to get
• 9:09
  Speaker 5: one of these devices back because the data is, it's.
• 9:12
  Speaker 4: A logger, the data is on the device.
• 9:14
  Speaker 5: And we plug it in the computer and we're sitting
• 9:16
  Speaker 5: and waiting for hours because it's very slow, the download
• 9:19
  Speaker 5: is very slow. And then eventually we see this map
• 9:21
  Speaker 5: and we see what our bat did during the entire night.
• 9:23
  Speaker 5: And that was like, wow, mind blowing for me.
• 9:26
  Speaker 4: Okay.
• 9:27
  Speaker 5: And back to the results, sorry, this is a long
• 9:30
  Speaker 5: answer to a short question, but recently we showed actually
• 9:34
  Speaker 5: that bats can navigate using sound location in order to
• 9:41
  Speaker 5: probably build some kind of a map, acoustic map of
• 9:44
  Speaker 5: the environment, even over many, many kilometers. And they can
• 9:48
  Speaker 5: probably use sound only when they need to do so,
• 9:51
  Speaker 5: because they also have vision, so they can use that
• 9:53
  Speaker 5: when it's available. But when they need to, some bats
• 9:56
  Speaker 5: at least can probably navigate over many, many kilometers, just
• 10:00
  Speaker 5: based on the echoes, on the sounds of the environment,
• 10:04
  Speaker 5: which I think is maybe not surprising, but still really,
• 10:07
  Speaker 5: really mind-blowing.
• 10:10
  Speaker 4: Yossi, do you.
• 10:11
  Speaker 1: Think there's any scope in in that sort of what
• 10:16
  Speaker 1: we've learned about bats and this remarkable ability to use
• 10:20
  Speaker 1: sonar for the development of artificial sensing devices.
• 10:25
  Speaker 4: Yeah, of course. The simple answer is of course.
• 10:30
  Speaker 5: You know, people have been doing a lot of stuff
• 10:32
  Speaker 5: with radar for many, many years. You know, a lot
• 10:36
  Speaker 5: of military applications, but recently autonomous cars, autonomous vehicles, a
• 10:41
  Speaker 5: lot of civilian applications. I must say, you know, bats
• 10:45
  Speaker 5: are a million times better than anything we can do today,
• 10:49
  Speaker 5: even with the most sophisticated radar devices.
• 10:51
  Speaker 4: So take, you know, whatever.
• 10:55
  Speaker 5: American cutting-edge technology, I'm saying American because usually with military technologies,
• 11:01
  Speaker 5: usually it's there, and they will not come near to
• 11:04
  Speaker 5: the abilities of a bat, of a small bat which
• 11:07
  Speaker 5: is flying within vegetation, remembering where it is, as I said,
• 11:11
  Speaker 5: navigating kilometers, avoiding collision, hunting for prey, nothing can do this,
• 11:15
  Speaker 5: especially nothing in this size. Now, there are a lot
• 11:18
  Speaker 5: of similarities between sonar and radar. So a lot of
• 11:21
  Speaker 5: what we learn from sonar can be maybe applied with
• 11:27
  Speaker 5: radar systems as well. A big major difference is the range.
• 11:30
  Speaker 5: So echolocation sonar in air only works for very nearby objects.
• 11:36
  Speaker 5: And so you can only a bat can only see
• 11:38
  Speaker 5: right with its ears for up to meters away. Sometimes
• 11:41
  Speaker 5: that's an advantage. There are a lot of disadvantages. If
• 11:43
  Speaker 5: you think of a car on a on a road,
• 11:46
  Speaker 5: maybe it's not very good. But but sometimes there are
• 11:48
  Speaker 5: advantages because you don't get a lot of what we
• 11:50
  Speaker 5: call clutter, a lot of a lot of background on
• 11:53
  Speaker 5: undesirable noise when you have such a short range sensor.
• 11:58
  Speaker 5: And for example, we have been involved in a lot
• 12:01
  Speaker 5: of agriculture applications. So a colleague of mine and me
• 12:07
  Speaker 5: in the past few years, we've shown that we can
• 12:10
  Speaker 5: use this sonar in order to, for example, estimate yield. So,
• 12:16
  Speaker 5: you know, for example, you have a farmer with a
• 12:18
  Speaker 5: greenhouse is growing tomatoes. He wants to know or she
• 12:21
  Speaker 5: wants to know how many kilos of tomatoes.
• 12:24
  Speaker 4: Are there and are they ripe? Should we pick them?
• 12:28
  Speaker 5: How many trucks should I prepare to collect them? And
• 12:33
  Speaker 5: this is today, people are trying to do this with cameras,
• 12:38
  Speaker 5: not very successfully. And we've shown that sonar is advantageous.
• 12:43
  Speaker 5: Maybe I'll just say in a word, because And the
• 12:46
  Speaker 5: sound waves, which, you know, sonar uses sound waves, they
• 12:49
  Speaker 5: can penetrate the foliage, they can enter the vegetation and
• 12:55
  Speaker 5: provide information also from within, and a few other advantages.
• 13:00
  Speaker 5: But that's, I think, one interesting direction that can be
• 13:03
  Speaker 5: learned and applied.
• 13:04
  Speaker 1: Wow, I didn't expect you to say that, I have
• 13:07
  Speaker 1: to say, that's remarkable.
• 13:09
  Speaker 3: So along those lines, Jossie, and kind of following on,
• 13:11
  Speaker 3: you know, back in, I think it was 1974, the
• 13:14
  Speaker 3: American philosopher Thomas Nagel wrote a famous paper called What
• 13:18
  Speaker 3: Is It Like to Be a Bat? And you're a neuroecologist,
• 13:22
  Speaker 3: as you explained at the beginning. So you're interested in
• 13:25
  Speaker 3: how bats are sensing the world, how they're using that information.
• 13:28
  Speaker 3: Do we know, can we ever know? I know this
• 13:32
  Speaker 3: is a very philosophical question, but you have kind of
• 13:34
  Speaker 3: written about consciousness in bats as well. So what is
• 13:37
  Speaker 3: it like to be a bat, do you think, now
• 13:39
  Speaker 3: we're starting to understand how they sense the world around them?
• 13:44
  Speaker 4: That's my dream, first of all.
• 13:45
  Speaker 5: I mean, I would pay anything to be inside a
• 13:50
  Speaker 5: bat's brain for even one minute.
• 13:54
  Speaker 4: I would give everything I have. And I would never
• 13:56
  Speaker 4: be there, right?
• 13:57
  Speaker 5: That's, of course, the conclusion from Thomas Nigel's paper.
• 14:01
  Speaker 4: And by the way.
• 14:03
  Speaker 5: He's actually interviewed in the last prologue of the book.
• 14:07
  Speaker 4: There's a short interview with him.
• 14:09
  Speaker 5: I actually wrote this after the book was all, I
• 14:14
  Speaker 5: didn't think he was available. And then I got some
• 14:16
  Speaker 5: contact with him and it was very nice and interesting
• 14:18
  Speaker 5: to talk with. And he even told me the history
• 14:21
  Speaker 5: of where, why did he even write this paper about
• 14:23
  Speaker 5: a bat? Or at least one of the reasons that
• 14:25
  Speaker 5: he had a bat, he had a colony of bats
• 14:28
  Speaker 5: in his attic or roof. Yeah, and a bat entered
• 14:31
  Speaker 5: the house several times, I think, and he observed this
• 14:33
  Speaker 5: alien creature. And yeah, for me, you know, discovering the
• 14:36
  Speaker 5: history behind these things, you know, this is maybe people
• 14:38
  Speaker 5: who don't know, this is like one of the most
• 14:40
  Speaker 5: famous papers in philosophy. There's no student who goes through philosophy,
• 14:44
  Speaker 5: a degree in philosophy without reading this paper in his
• 14:47
  Speaker 5: first or first year. Yeah, so, of course, we will
• 14:51
  Speaker 5: never know what it is like to be a bat, right?
• 14:52
  Speaker 5: That's the hard problem, right?
• 14:54
  Speaker 3: Your work is kind of giving us a little bit
• 14:56
  Speaker 3: of a better idea than Nagel would have known, right?
• 15:00
  Speaker 4: Yeah, yeah.
• 15:01
  Speaker 5: So, I will never know what it is to be
• 15:03
  Speaker 5: Seymour Thiem, right? That's the whole problem. But still, I
• 15:07
  Speaker 5: can try to study it and try to imagine. there's
• 15:11
  Speaker 5: still fundamental questions that we don't know. For example, you know,
• 15:14
  Speaker 5: can and does a bat reconstruct a 3D image of
• 15:18
  Speaker 5: the world based on the acoustics? So we know that
• 15:21
  Speaker 5: bats can do like as we do with vision, right?
• 15:23
  Speaker 5: So we know that bats do a lot, right? They classify,
• 15:26
  Speaker 5: they identify objects, they avoid collisions, they detect other bats,
• 15:30
  Speaker 5: and they do.
• 15:31
  Speaker 4: All of this with sound.
• 15:32
  Speaker 5: But what exactly does the representation of the world, of
• 15:36
  Speaker 5: the acoustic world look like in their brain?
• 15:38
  Speaker 4: We have no clue.
• 15:40
  Speaker 5: Maybe I can tell you about one study where I
• 15:43
  Speaker 5: like to say we went one step closer to a
• 15:47
  Speaker 5: to understanding what it is like to be a bat.
• 15:50
  Speaker 5: In this paper, by the way, this was one of the, again,
• 15:53
  Speaker 5: I don't know if surprising, but one of the most interesting,
• 15:55
  Speaker 5: I think, findings that we had in the past.
• 15:57
  Speaker 4: A few years.
• 15:58
  Speaker 5: What we did is we tried to change. So everything,
• 16:01
  Speaker 5: of course, for sonar, everything depends on the speed of sound, right?
• 16:05
  Speaker 5: Because you emit a call, an echo, you receive an echo,
• 16:10
  Speaker 5: and then your brain using the speed of sound computes that,
• 16:12
  Speaker 5: you know, the wall in front of me is a
• 16:14
  Speaker 5: meter and a half or something like that. Now, We
• 16:17
  Speaker 5: know that the speed of sound is not constant.
• 16:19
  Speaker 4: It changes.
• 16:20
  Speaker 5: It changes depending on temperature. It changes with pressure. And
• 16:24
  Speaker 5: we were wondering whether bats can, whether this is flexible,
• 16:27
  Speaker 5: whether when they're flying around, they can somehow assess the
• 16:29
  Speaker 5: speed of sound and adjust their sensing.
• 16:31
  Speaker 4: Because if not, they would be inaccurate, right?
• 16:35
  Speaker 5: And, you know, I'm not going into all of the details,
• 16:37
  Speaker 5: but one of the things that we've done in this
• 16:39
  Speaker 5: study is to actually rear young pups, young bats in
• 16:43
  Speaker 5: a helium enriched environment. So we changed their world. Yeah,
• 16:47
  Speaker 5: we changed their world. Basically, we created the world where
• 16:49
  Speaker 5: the speed of sound is faster. And then we asked,
• 16:53
  Speaker 5: by carefully examining their echolocation, whether it is different from
• 16:57
  Speaker 5: other bats that grew up in a normal environment where
• 17:01
  Speaker 5: the airspeed is the same as yours and mine. And again,
• 17:06
  Speaker 5: without all of the technical details, the result was both
• 17:10
  Speaker 5: groups sensed the world completely exactly the same.
• 17:13
  Speaker 4: So there was no difference.
• 17:15
  Speaker 5: Which brought us to the conclusion that the speed of
• 17:17
  Speaker 5: sound is hardwired, if you wish. There's like a fixed
• 17:22
  Speaker 5: reference of the speed of sound in their brain, It
• 17:25
  Speaker 5: probably has been written by evolution. And it does not
• 17:31
  Speaker 5: change depending on the environment. So in one of the experiments,
• 17:33
  Speaker 5: the cool experiment that we've done, the bats had to
• 17:36
  Speaker 5: land on a target at a certain distance. And when
• 17:39
  Speaker 5: you enrich the environment with helium, they underestimate because the
• 17:43
  Speaker 5: speed of sound is faster. So they perceive the object
• 17:46
  Speaker 5: as being closer. And they land before the target. And
• 17:52
  Speaker 5: they're puzzled, and then they try climbing on it. And
• 17:55
  Speaker 5: then they learn to compensate, but they don't learn the
• 17:57
  Speaker 5: new speed of sound. So you see them once every
• 18:00
  Speaker 5: 10 trials, they will kind of flap harder and arrive
• 18:04
  Speaker 5: at the target.
• 18:05
  Speaker 4: That's really interesting.
• 18:06
  Speaker 2: That's amazing.
• 18:07
  Speaker 4: Yeah, yeah.
• 18:08
  Speaker 5: This is, by the way, a student of mine, Rana Mikhai,
• 18:10
  Speaker 5: who's done all of this work. This is a lot
• 18:12
  Speaker 5: of very difficult work. You have to keep the helium
• 18:14
  Speaker 5: environment constant. And, you know, it's very, very difficult, a
• 18:16
  Speaker 5: lot of work. And I think we depleted the helium
• 18:21
  Speaker 5: resources of the world.
• 18:22
  Speaker 2: The kids become high in pitch. Because if we drink,
• 18:25
  Speaker 2: if we... I sound a little bit like Simon.
• 18:29
  Speaker 4: Right. So no, and we were wondering, and I'll explain.
• 18:33
  Speaker 4: At first, I also wasn't sure why.
• 18:35
  Speaker 5: And the reason is that what happens, your vocal cords
• 18:39
  Speaker 5: still oscillate at the same frequency, but we have multiple resonances.
• 18:43
  Speaker 5: And what happens when you change the speed of sound
• 18:46
  Speaker 5: in this vocal tract of yours, then the higher harmonics
• 18:51
  Speaker 5: become emphasized. And it's not as if the basic oscillation changes,
• 18:57
  Speaker 5: just the emphasis changes. And with bats, since they use
• 19:01
  Speaker 5: a very, very wide band signal, maybe you will see
• 19:05
  Speaker 5: a slight change of energy, but basically it's.
• 19:07
  Speaker 4: Not something that is easy to measure. It more or
• 19:09
  Speaker 4: less stays the same.
• 19:11
  Speaker 5: I just want to say, so how does this bring
• 19:13
  Speaker 5: us closer to understanding what it is like to be
• 19:16
  Speaker 5: a bat?
• 19:16
  Speaker 4: Again, just maybe one millimeter closer.
• 19:20
  Speaker 5: So if the speed of sound is fixed, this is
• 19:24
  Speaker 5: like saying, basically, this is kind of a philosophical jump,
• 19:28
  Speaker 5: but it's like saying there is no speed of sound.
• 19:30
  Speaker 4: Because it doesn't matter.
• 19:31
  Speaker 5: It's multiplying everything by a fixed number. So it's like
• 19:34
  Speaker 5: not multiplying it at all. And this kind of brought
• 19:37
  Speaker 5: me to the conclusion. And by the way, Jim Simmons
• 19:40
  Speaker 5: in Brown has said this for years. But for me,
• 19:42
  Speaker 5: this is a kind of it's kind of confirming his
• 19:44
  Speaker 5: hypothesis that the bat's brain doesn't work with distance. It
• 19:47
  Speaker 5: actually works with time, at least when using expectations. So
• 19:51
  Speaker 5: things around it are 10 milliseconds away and not 1.7
• 19:55
  Speaker 5: meters away. And I think this is a small, small
• 19:59
  Speaker 5: step in understanding bats better.
• 20:03
  Speaker 2: Simon.
• 20:04
  Speaker 1: So Yossi, do you think sort of the work you've
• 20:06
  Speaker 1: done on understanding bats in any way gives you a
• 20:11
  Speaker 1: broader understanding of sort of animal cognition and the ways
• 20:15
  Speaker 1: this sort of sensory perception and processing happens in animals
• 20:19
  Speaker 1: in general?
• 20:22
  Speaker 4: For sure.
• 20:23
  Speaker 5: I mean, we always, you know, as biologists, we always
• 20:27
  Speaker 5: have to think about the general picture. I mean, we
• 20:30
  Speaker 5: are also sometimes interested in the unique, right? Sometimes discovering
• 20:34
  Speaker 5: some animal that is doing something very unique is also.
• 20:38
  Speaker 4: Worthy and also important. But we also think generally.
• 20:42
  Speaker 5: So in the past, I started off as what we
• 20:46
  Speaker 5: call a sensory ecologist, really, really interested in sensing. More
• 20:51
  Speaker 5: and more, I became interested in other behaviors. We study
• 20:55
  Speaker 5: social behavior, vocal communication, navigation, which we already discussed. All
• 21:05
  Speaker 5: of these are general cognitive capacities or behaviors that other
• 21:09
  Speaker 5: animals have. And, you know, in one study, for example,
• 21:14
  Speaker 5: we show maybe this is, I'm thinking which of the
• 21:18
  Speaker 5: studies to mention. So there is a study where we
• 21:21
  Speaker 5: show how fruit bat pups learn to navigate. Okay, so
• 21:26
  Speaker 5: these pups, you know, imagine you're a bat. you've spent
• 21:31
  Speaker 5: your first two months in a cave and then you
• 21:33
  Speaker 5: fly out for the first time and you can easily
• 21:37
  Speaker 5: fly 50 kilometers easily without any problem. And then you
• 21:41
  Speaker 5: need to find your way back home. It's crazy.
• 21:43
  Speaker 4: It's impossible. I mean, when we leave a hotel room
• 21:46
  Speaker 4: in a new city and try.
• 21:48
  Speaker 5: To find our way back right from 500 meters, we're
• 21:51
  Speaker 5: lost sometimes if we don't pay careful attention to the
• 21:54
  Speaker 5: to where we walked, or we use a map, or
• 21:57
  Speaker 5: today it's an app. So what we found is that
• 22:00
  Speaker 5: these bats, their mothers will carry them out from the
• 22:05
  Speaker 5: cave and place them on a tree that is somewhere
• 22:08
  Speaker 5: around a kilometer from the cave. And then the mothers
• 22:11
  Speaker 5: will forage. They will fly very far and come back
• 22:15
  Speaker 5: after several hours, collect them and take them back home.
• 22:18
  Speaker 5: And they do this again and again, night after night
• 22:21
  Speaker 5: for several weeks. I don't remember exactly the number. And
• 22:25
  Speaker 5: then after more or less two and a half, at
• 22:28
  Speaker 5: the age of more or less two and a half months,
• 22:30
  Speaker 5: The mothers will fly out and just leave their pups
• 22:32
  Speaker 5: in the cave, okay? And we interpret this as, okay,
• 22:36
  Speaker 5: now you're on your own. You have to just go out.
• 22:40
  Speaker 5: And most pups will go out. Some will not, by
• 22:41
  Speaker 5: the way. And then the mothers will go back one
• 22:43
  Speaker 5: step backwards, show them the behavior, do the behavior again,
• 22:46
  Speaker 5: and then go out. And we interpret this as kind
• 22:48
  Speaker 5: of encouraging them to go out. And indeed what we
• 22:52
  Speaker 5: find is that the pups, the first thing they will
• 22:54
  Speaker 5: do is to fly to the same tree where the mothers,
• 22:58
  Speaker 5: we call it the drop-off tree, where they drop them
• 23:00
  Speaker 5: off during the past several weeks. And they will follow
• 23:03
  Speaker 5: the same route, which is surprising because it seems like
• 23:05
  Speaker 5: they're learning to navigate even though they're carried. And we
• 23:08
  Speaker 5: know that passive learning is very difficult, right? When we,
• 23:10
  Speaker 5: like backseat driving is very difficult. We don't learn much.
• 23:17
  Speaker 4: In these situations.
• 23:18
  Speaker 5: So the pups seem to be learning And we interpret
• 23:21
  Speaker 5: this tree as a kind of an anchor for navigation
• 23:25
  Speaker 5: to avoid the situation that I described before. So now
• 23:29
  Speaker 5: the pup, there is one place that it knows, you know,
• 23:31
  Speaker 5: it's like teaching your child.
• 23:32
  Speaker 4: Maybe to walk to school or something like that.
• 23:34
  Speaker 5: There is one place where you know how to get
• 23:37
  Speaker 5: to and you know how to get home from. And
• 23:40
  Speaker 5: then from there on, and that's what the pups do.
• 23:42
  Speaker 5: We know this because we place the GPS on the
• 23:44
  Speaker 5: pup as well. From there on, you start exploring the
• 23:47
  Speaker 5: world carefully. You move a little bit farther on your
• 23:49
  Speaker 5: own and you start discovering new trees.
• 23:52
  Speaker 4: But there is an.
• 23:52
  Speaker 5: Anchor from where you can find your way back home.
• 23:56
  Speaker 5: And we even had one very remarkable case in which
• 24:01
  Speaker 5: the pup went out. Like I said, it was on
• 24:03
  Speaker 5: the tree. The mother came back to the cave. This
• 24:06
  Speaker 5: is already 3 a.m. And the pup is not there.
• 24:09
  Speaker 5: And an hour later, so, you know, again, if I'm
• 24:11
  Speaker 5: trying to put myself inside the bat, she's like, where's
• 24:15
  Speaker 5: my pup?
• 24:15
  Speaker 4: Where's my pup? Because they still lactate at this time,
• 24:19
  Speaker 4: at this period. And so where is it?
• 24:21
  Speaker 2: Nowhere.
• 24:21
  Speaker 4: Okay.
• 24:22
  Speaker 5: At 4 a.m., an hour later, she flies out. Where
• 24:25
  Speaker 5: does she go to? To the same tree. She knows
• 24:27
  Speaker 5: that's probably where I can find it. And indeed, she
• 24:29
  Speaker 5: finds it there and brings it back home. So again,
• 24:34
  Speaker 5: I don't know exactly if this is what other animals do,
• 24:36
  Speaker 5: but I can imagine that this is a very good
• 24:38
  Speaker 5: general strategy to teach your pup how to orient in
• 24:43
  Speaker 5: space and navigate.
• 24:44
  Speaker 2: We should have a brief break at this point, so
• 24:47
  Speaker 2: we will return shortly.
• 24:49
  Speaker 1: Hi, Tim. You're looking particularly snazzy today. What are you wearing?
• 24:54
  Speaker 2: I'm wearing a piece from a company called Grace and Garbo.
• 24:58
  Speaker 3: And actually, you know a little bit more about them
• 25:00
  Speaker 3: than I do, to be honest.
• 25:01
  Speaker 1: Yeah, you're right, I do.
• 25:03
  Speaker 3: You're the fashion queen.
• 25:05
  Speaker 1: I'm also wearing a piece from Grayson Garbo. So this
• 25:07
  Speaker 1: is a delightful knitwear outfit set up in Birmingham. What
• 25:13
  Speaker 1: they do is they source knitwear, quality knitwear from all
• 25:16
  Speaker 1: around the world. It's vintage, one-off pieces, many of which
• 25:20
  Speaker 1: they then hand embellish, like the one you're wearing today
• 25:23
  Speaker 1: with its beautiful purple flowers. And so they're big on
• 25:26
  Speaker 1: sustainability and You know, nothing goes to waste. Everything is
• 25:31
  Speaker 1: sort of recycled and reused. And if you want to
• 25:34
  Speaker 1: know more about them, then have a look at the
• 25:36
  Speaker 1: link beneath this episode.
• 25:38
  Speaker 3: And thank you very much to them for supporting our podcast.
• 25:41
  Speaker 2: I hope their sales soar.
• 25:44
  Speaker 1: Thanks a lot, Grace and Garvo.
• 25:47
  Speaker 3: So welcome back. We're talking to Yossi Yovel about bats.
• 25:51
  Speaker 3: And so we'll just, you know, two or three more
• 25:54
  Speaker 3: questions because we're running out of time here. But I mean,
• 25:58
  Speaker 3: you're talking a little bit about social context there. So
• 26:00
  Speaker 3: you were just been talking about mums and their offspring.
• 26:04
  Speaker 3: But how do bats use echolocation in social contexts? So
• 26:09
  Speaker 3: as well as finding their way around, do they use
• 26:12
  Speaker 3: it to communicate with one another?
• 26:13
  Speaker 2: Do they pass information between them?
• 26:16
  Speaker 4: Yeah.
• 26:17
  Speaker 3: Yeah.
• 26:18
  Speaker 5: So, yeah, indeed, this is one of the, I think,
• 26:20
  Speaker 5: the most interesting questions that many researchers are interested in. And, yeah,
• 26:27
  Speaker 5: like you said, echolocation is something that is currently out there.
• 26:31
  Speaker 4: Its major use is.
• 26:33
  Speaker 5: Sensing, but it makes sense that if it's currently available,
• 26:37
  Speaker 5: then other.
• 26:38
  Speaker 4: Bats would learn to use or to extract information.
• 26:42
  Speaker 5: Now, perhaps the most interesting common case, is eavesdropping. So
• 26:49
  Speaker 5: when a bat is attacking prey, the echolocation sequence becomes much,
• 26:54
  Speaker 5: much faster. So if in the normal situation we're searching
• 26:58
  Speaker 5: for prey, a bat would emit a signal every 100 milliseconds,
• 27:02
  Speaker 5: something like, this is a slowed down.
• 27:04
  Speaker 4: Version, toot, toot.
• 27:07
  Speaker 5: When it is closing in on a prey, it will
• 27:09
  Speaker 5: go up to 200 emissions per second, even at the
• 27:13
  Speaker 5: fastest rate.
• 27:14
  Speaker 4: So it will go up to.
• 27:16
  Speaker 5: Okay, which is also fascinating because they're acquiring more information, basically.
• 27:20
  Speaker 5: But for a different bat, what we call a conspecific, right?
• 27:24
  Speaker 5: This means that somebody is attacking food. It means that
• 27:27
  Speaker 5: somebody found food, basically. And it is known for many,
• 27:31
  Speaker 5: many researchers have shown that bats are attracted to these sounds.
• 27:34
  Speaker 5: They know that somebody else has found food. And you
• 27:37
  Speaker 5: can even see interspecific interest or interaction. So if these
• 27:42
  Speaker 5: are species that feed on similar food, they will eavesdrop
• 27:45
  Speaker 5: on other individuals from a different species. What we have
• 27:49
  Speaker 5: shown with our work with the GPSs is that these
• 27:53
  Speaker 5: echolocation signals can also be used probably just for tracking together.
• 27:57
  Speaker 4: So some bats benefit from moving in.
• 28:00
  Speaker 5: A collective and searching in a group because when food
• 28:06
  Speaker 5: is patchily distributed, so it's hard to find the food,
• 28:08
  Speaker 5: but there's a lot of food. Imagine a swarm of
• 28:11
  Speaker 5: insects moving. then it makes sense to search in a
• 28:13
  Speaker 5: group because if somebody finds food, everybody will find food. Basically,
• 28:17
  Speaker 5: we show using modeling that these bats can spread out
• 28:20
  Speaker 5: in space. Eaves search individually but also listen to the
• 28:25
  Speaker 5: echolocation signals of others and the search becomes much more
• 28:29
  Speaker 5: effective when they do so. Again, they're only using echolocation.
• 28:32
  Speaker 5: Nobody is communicating directly. Nobody is saying, look, I am
• 28:36
  Speaker 5: number one, follow me. there is food here, it is
• 28:39
  Speaker 5: only based on listening to their echolocation signals.
• 28:44
  Speaker 2: Really interesting.
• 28:45
  Speaker 4: Saima?
• 28:46
  Speaker 1: Yes, so actually, Yossi, I wanted to just change tack
• 28:49
  Speaker 1: a little bit now and ask you about this intriguing
• 28:52
  Speaker 1: BBC article about your work on basically animals reacting to
• 29:00
  Speaker 1: secret sounds from plants.
• 29:03
  Speaker 4: Is the headline.
• 29:04
  Speaker 1: Can you tell us a little bit more about this?
• 29:07
  Speaker 4: Sure, sure.
• 29:08
  Speaker 5: Yeah, so a few years ago, we started studying plant sounds.
• 29:13
  Speaker 5: A colleague of mine, Lila Hadani, she's an evolutionary biologist
• 29:19
  Speaker 5: who studies plants, came up with the idea of recording plants.
• 29:22
  Speaker 4: I was skeptical.
• 29:24
  Speaker 5: But, you know, we have a lot of ultrasonic equipment
• 29:28
  Speaker 5: in the.
• 29:29
  Speaker 4: Lab, so we said, why not? And her student....
• 29:32
  Speaker 5: Or a joint student came to me and said, look,
• 29:34
  Speaker 5: look at these clicks. There are clicks constantly. And I said,
• 29:37
  Speaker 5: that must be an artifact. We know that these systems
• 29:39
  Speaker 5: create a lot of clicks and we took a lot of,
• 29:43
  Speaker 5: you know, we ran a lot of controls, mostly placing
• 29:47
  Speaker 5: several different microphones together and making sure that if it's noise,
• 29:50
  Speaker 5: internal noise, you would not see correlations in the different microphones.
• 29:53
  Speaker 5: And for sure, these plants emit ultrasonic or produce ultrasonic clicks,
• 30:01
  Speaker 5: very brief signals around 50 kilohertz. Now, I must say,
• 30:04
  Speaker 5: after observing this and being convinced, we read the literature
• 30:07
  Speaker 5: and we found that a lot of people have described vibrations.
• 30:11
  Speaker 5: So a lot of people have described placing your sensor
• 30:14
  Speaker 5: on the plant the stem mostly, and then you see
• 30:17
  Speaker 5: that the plant is vibrating in these frequencies. It was
• 30:20
  Speaker 5: all about just checking whether the sound is airborne, which
• 30:24
  Speaker 5: is what we did. Now, of course, if the sound
• 30:26
  Speaker 5: is airborne, it means that other organisms can sense it, potentially.
• 30:31
  Speaker 5: That immediately drew my interest as a bioacoustician and somebody
• 30:36
  Speaker 5: who's interested in animal acoustics and sound. So, you know,
• 30:40
  Speaker 5: we started thinking, okay, which animals can hear these high-frequency sounds? Bats, rodents,
• 30:46
  Speaker 5: there are some mammals, of course, that can do this. And,
• 30:49
  Speaker 5: of course, there are a lot of insects. And we
• 30:51
  Speaker 5: had to think of a model that we can study
• 30:54
  Speaker 5: and that would also be relevant. And we decided to
• 30:58
  Speaker 5: study moths. Many moths can hear ultrasound. There are different
• 31:03
  Speaker 5: hypotheses why they evolve disability.
• 31:05
  Speaker 4: One of them is to avoid bat predation, actually.
• 31:08
  Speaker 5: There's a whole chapter about this in my book.
• 31:11
  Speaker 4: But it might also be social.
• 31:13
  Speaker 5: So male moths also emit courtship clicks in high frequency clicks.
• 31:21
  Speaker 5: and uh but we know that um for a moth
• 31:25
  Speaker 5: laying so the one of the main interactions of a
• 31:27
  Speaker 5: female moth with the plant is when it lays its
• 31:29
  Speaker 5: eggs right because it wants to uh to find a
• 31:33
  Speaker 5: good hydrated plant where it's a descendant right where it's
• 31:37
  Speaker 5: offspring will not be eaten by a predator and the
• 31:40
  Speaker 5: plant is not too dry or something like that ah
• 31:43
  Speaker 5: now i forgot to say is that we found that
• 31:44
  Speaker 5: the plants produce more of these sound clicks when they
• 31:49
  Speaker 5: are dehydrated. There's information there that might be relevant for
• 31:53
  Speaker 5: the organisms, and this is one of the main ones.
• 31:58
  Speaker 5: We decided to run a classical sensory ecology task where
• 32:03
  Speaker 5: we have the animal, the female moth.
• 32:06
  Speaker 4: It's about to lay its eggs. It has been fertilized.
• 32:10
  Speaker 5: And it has two options either to lay it, maybe
• 32:15
  Speaker 5: I'll describe.
• 32:16
  Speaker 4: One of the experiments because there were several.
• 32:17
  Speaker 5: So in one of the experiments there are two plants,
• 32:20
  Speaker 5: they're both hydrated, they're identical as much as we can see,
• 32:23
  Speaker 5: but one of them is associated with a speaker that
• 32:28
  Speaker 5: we place of course that is playing these sounds that
• 32:32
  Speaker 5: plants usually, so these are tomato plants, And these are
• 32:35
  Speaker 5: sounds that tomato plants produce when they are dehydrated. So
• 32:39
  Speaker 5: we basically recorded these sounds ourselves and we are now
• 32:44
  Speaker 5: producing them. And what we found is that the moth
• 32:48
  Speaker 5: will prefer significantly to lay its eggs on the silent sound,
• 32:53
  Speaker 5: the silent plant. So, you know, the non-dehydrated plant, basically,
• 33:00
  Speaker 5: and this is very, very significant.
• 33:02
  Speaker 4: We have a lot of controls. I think we don't
• 33:04
  Speaker 4: have time to go into them.
• 33:04
  Speaker 5: But I think this is a very strong indication that
• 33:07
  Speaker 5: moths take sound into account when making decisions about where
• 33:12
  Speaker 5: to lay their eggs and probably plant sounds when doing so.
• 33:17
  Speaker 3: No, it's fascinating stuff. There's all this noise and all
• 33:19
  Speaker 3: this communication going on out there. Next time I'm out
• 33:22
  Speaker 3: in the garden, I'm going to be listening to see
• 33:24
  Speaker 3: which tomato plant to harvest. But we're coming towards, we
• 33:30
  Speaker 3: better wrap up because we're sort of running out of time.
• 33:32
  Speaker 3: But thank you very much for joining.
• 33:34
  Speaker 2: Us, Yossi.
• 33:35
  Speaker 3: And again, for our listeners and our readers, your book
• 33:40
  Speaker 3: is just out.
• 33:41
  Speaker 2: It's called The Genius Bat.
• 33:43
  Speaker 3: The subtitle in Europe is Understanding Our Most Mysterious Mammal.
• 33:47
  Speaker 2: It's really well worth a read. It's fantastic. And I
• 33:50
  Speaker 2: think you've got the American version there as well. Perhaps
• 33:53
  Speaker 2: you want to hold that up. There we go. It's blurred.
• 33:58
  Speaker 2: Maybe I can remove it.
• 34:00
  Speaker 3: Maybe hold it close to your head because your head
• 34:02
  Speaker 3: is in focus.
• 34:05
  Speaker 4: There, there.
• 34:07
  Speaker 3: Yeah, it's a really, I mean, bats are just, you know,
• 34:10
  Speaker 3: there's a large number of species. They're fascinating individuals. great
• 34:14
  Speaker 3: personal stories as well.
• 34:16
  Speaker 2: And you've gone and interviewed, you know, as you, as
• 34:18
  Speaker 2: you mentioned various people in the field.
• 34:19
  Speaker 3: So congratulations on the book and I hope it does
• 34:22
  Speaker 3: really well. So thank you very much for joining us, Shossi.
• 34:25
  Speaker 4: Thank you very much. It was a pleasure.
• 34:28
  Speaker 2: Well, that was really interesting assignment.
• 34:30
  Speaker 3: I mean, you know, isn't it interesting the way he's
• 34:33
  Speaker 3: bringing together the sort of ecology. We didn't talk about
• 34:36
  Speaker 3: the conservation, but he has been in his book about
• 34:38
  Speaker 3: that as well. But, um, uh, but bringing the ecology
• 34:41
  Speaker 3: and the neuroscience, as it were, of bats together. And
• 34:47
  Speaker 3: I just thought it was fascinating.
• 34:49
  Speaker 1: Yeah, me too. And also the sort of technological aspects
• 34:52
  Speaker 1: and the sort of applications. I mean, I think I
• 34:55
  Speaker 1: really genuinely wasn't expecting him to say what he said
• 34:58
  Speaker 1: about the agricultural use, where they're using it to sort
• 35:03
  Speaker 1: of check up on the ripeness and abundance of tomato plants.
• 35:09
  Speaker 3: But it's also amazing, isn't it, that bats have been
• 35:12
  Speaker 3: around for millions of years, but they're clearly way, way
• 35:16
  Speaker 3: better at using sonar and echolocation than anything we're capable
• 35:21
  Speaker 3: of doing yet.
• 35:22
  Speaker 1: Yeah, yeah, well, absolutely. I mean, I think both of
• 35:27
  Speaker 1: us are probably, you know, this is why we're sort
• 35:30
  Speaker 1: of biologists, right? Biology does things, still does things better
• 35:34
  Speaker 1: than we do synthetically, right?
• 35:37
  Speaker 3: Yeah, but also, isn't it amazing? There's a whole other
• 35:40
  Speaker 3: sense out there that we don't experience. You know, that echo,
• 35:43
  Speaker 3: you know, wandering. You know, if I tried to walk
• 35:46
  Speaker 3: around Tesco's foraging for food with my eyes shut clicking, well,
• 35:50
  Speaker 3: not only would I probably be arrested, but I'd walk
• 35:52
  Speaker 3: into the Weetabix and, you know, probably stumble into the milk.
• 35:57
  Speaker 2: Fridge or something.
• 35:58
  Speaker 1: If you try it, will you video it for our viewers?
• 36:01
  Speaker 2: LAUGHTER No.
• 36:04
  Speaker 3: And I mean, it's clear as well from what he
• 36:07
  Speaker 3: was saying about the way they've shrunk down technology, but
• 36:10
  Speaker 3: they are really starting to sort of get a much
• 36:14
  Speaker 3: better understanding of how they collect information, how these bats
• 36:18
  Speaker 3: collect information. and and how they can use it to
• 36:21
  Speaker 3: navigate and the fact they train their young in that
• 36:23
  Speaker 3: way as well i thought that was i didn't know
• 36:25
  Speaker 3: any of that at.
• 36:26
  Speaker 2: All that was in his book.
• 36:27
  Speaker 1: But yeah that was absolutely beautiful the the tree using
• 36:31
  Speaker 1: the trees and then sort of can't find the pup
• 36:34
  Speaker 1: but let's go and check it check in the tree
• 36:36
  Speaker 1: it's most likely to be there yeah no.
• 36:39
  Speaker 3: It's a it no it's really cool stuff i enjoyed
• 36:42
  Speaker 3: it and And I mean, there are, I guess there's,
• 36:45
  Speaker 3: it's interesting as well that insects and moths as well
• 36:48
  Speaker 3: are also using some of this echolocation. And the fact
• 36:51
  Speaker 3: these poor plants, they get stressed, they can't like help themselves,
• 36:54
  Speaker 3: but they're clicking away, you know, and then that's bringing
• 36:58
  Speaker 3: in that, well, the moths laying their eggs were avoiding it,
• 37:01
  Speaker 3: but it probably brings in pest insects as well, right?
• 37:04
  Speaker 3: They'll probably think, oh, look, there's a weak plant.
• 37:07
  Speaker 1: Yeah, I mean... As you know, I sort of laughed
• 37:10
  Speaker 1: when you said it, but there's a really serious point
• 37:12
  Speaker 1: that there's this whole sort of world in our world
• 37:16
  Speaker 1: that we don't experience. As you said, we're walking around
• 37:18
  Speaker 1: and actually this whole everything's a battleground, right? Sort of
• 37:23
  Speaker 1: plants and animals and things we can see, things we
• 37:26
  Speaker 1: can't see. communicating in ways we can perceive in ways
• 37:29
  Speaker 1: we can't so there's sort of like multi-layers of communication
• 37:33
  Speaker 1: battle whatever going on that we we're completely ignorant of
• 37:37
  Speaker 1: as we walk around.
• 37:37
  Speaker 3: No and there's still so much more to learn and
• 37:40
  Speaker 3: i think that's kind of one of the things that
• 37:41
  Speaker 3: came across and you know um we you know we
• 37:45
  Speaker 3: still don't know what it's like to be a bat.
• 37:48
  Speaker 2: Well i don't So you're not a vampire after all,
• 37:54
  Speaker 2: is that what you're saying?
• 37:55
  Speaker 1: I don't think so.
• 37:58
  Speaker 2: Well, look, I better go. But it's been great as
• 38:00
  Speaker 2: ever to see you. And we'll see you for next
• 38:04
  Speaker 2: week's episode.
• 38:05
  Speaker 4: Yeah, absolutely.
• 38:06
  Speaker 1: Take care, Tim.
• 38:07
  Speaker 2: Okay, yeah, and you. Bye now.
• 38:08
  Speaker 4: Bye, everyone.