Episode Transcript
[00:00:03] Speaker A: Welcome to Brain junk. I'm Trace Kerr.
[00:00:05] Speaker B: And I'm Amy Barton. And this is technically, it's more of everything you never knew you wanted to know about bats.
Even more bonus material. So, last, if you haven't listened to our previous bat episode, it's delightful. Please go check it out. It talks about the way bats communicate with each other. And they have some delightful communications. They're very concerned about their personal space and boundaries. And scientists have recorded and can tell the different kinds of conversations that bat have together.
[00:00:39] Speaker A: It'll be in the show notes which one it is. There'll be a link, don't worry.
[00:00:42] Speaker B: Yeah, they're very concerned about their personal space. It's a whole thing for them.
And so, in the past, scientists have known about two kinds of vocalizations that bats make. They use it for, of course, echolocation and communicating with each other. And we're going to talk about a third one later in the episode. I'm getting ahead of myself because I really like everything about this episode. Let's talk about. The first thing that pulled me into this topic was the question of how. How do bats avoid each other? How do they not run into each other mid air? And in April of 2015, Doctor Mark Holderide, he's a bat biologist from the University of Bristol, wanted to answer that question. And so he observed, they recorded some footage and watched this infrared camera footage with also floodlights, and found that bats have a pretty simple way of avoiding each other when they're mid air and they see each other coming. When they encounter each other, they almost immediately match spot speed and direction and fall into formation. And so they make these, like, when you see birds do that in the sky where they suddenly are flying together, they're coming toward each other, and then they just sort of look like they're doing air ballet. And that keeps from, like, catastrophic mashups, and it seems to keep them incident free. However, now a scientist, a couple scientists named Nikola, Nikolay Kistrov, and Louise Allen have used military grade high speed cameras, thermal cameras. Bats run into each other all the time.
[00:02:30] Speaker A: I was gonna say. I was gonna say, aren't they smacking into each other?
[00:02:35] Speaker B: Yes, they are.
They are mostly elegant. It's like that transition where a kid is learning to walk, where when they leave the cave is what it looks like. So there is. There will be a YouTube video in the notes because I promise to share my links with trace and look at. Oh, this is the trace. This is the link I sent you. So roll to minute 520 and start watching.
[00:03:01] Speaker A: Okay.
[00:03:01] Speaker B: And let me see here. It's gonna look like this transition from toddler. Toddler like fluent walker. As they're flying out of the cave, they're sort of, they have these derpy moments where it's like, whoops, pardon me. And they bump and then they recover and go on.
[00:03:20] Speaker A: It's lens of time bat ballet. Oh. Oh. That wasn't very graceful.
[00:03:26] Speaker B: No. But they don't seem to like fall out of the sky and hit the ground. They just sort of bumble and they're like, whoops. And they kind of keep going.
[00:03:35] Speaker A: Cause they're all coming out of the cave at the same time. This is kind of like when you got a big crowd of people going into the subway, right?
[00:03:42] Speaker B: Yes.
[00:03:42] Speaker A: And you're all trying to keep your space. And it's like, oh, shoulder. Oh, I hip checked you. Sorry about that.
[00:03:48] Speaker B: Yeah. And then once you bump somebody, you bump somebody else. And the video trace is watching is. And that you should also watch unless you're in your car.
It is brazilian free tailed bats. And they are the sort that you would find in central Texas. So in San Antonio and Austin, where you can go and see bats emerging from their homes in the afternoon.
This is those kind of bats. They make their homes in caves and tunnels and wells and sometimes homes in people homes. And they have long slender wings and are great at long distance flight. But that is not good for short term maneuverability in that exiting too many people too close together, it does not go great.
So Doctor Mark Holdroyd is right. They do. Sometimes you watch that video and you're like, look at those guys. That was great. And then also right next to them, some bumping together. I suspect the in tandem direction change is when they have exited that pinch point. Once they're out with more space, you've.
[00:05:02] Speaker A: Got these long arms and they're just sticking out.
[00:05:05] Speaker B: Yeah. Yep.
[00:05:07] Speaker A: This is nature. It is graceful. They are so much better than we are. And then our technology gets better and we're like, actually it's a train wreck.
[00:05:15] Speaker B: Yeah. Oh, oh, look out. Yeah.
So it's worth queuing up that video. And the commentary of the people doing the video is fun too. So bats are banging into each other like a bunch of toddlers after nap time, but they're getting it done, it's fine. Here's another area that's hard for bats. We probably kind of know this too. Like modern buildings are a problem for bats. Those shiny, sleek surfaces when bats are coming in at an angle, particularly their echolocation does them wrong. And it tells that it bounces off that smooth plate. And so it gives the bat this idea that, no, that's not a thing. It just slides off. And so they don't see it as a flat surface. It reflects. Reflects. The word reflect is hard for me today. But what it's happening is that echolocation, because I'm like, wait a minute. It doesn't bounce. If it bounced, it would be good, but it doesn't. It just sort of reflects away. And so the bats think they're flying into a wide open space. And so that's another area that I think environmentalists are like, hey, this is a bummer, you guys. Let's do something. But the rest of us are like, but windows are so shiny. It's great.
[00:06:31] Speaker A: We just cover them with carpet. It'll be fine.
[00:06:35] Speaker B: And the tests they watch are also like the bats when they bump into each other. They tested it in an area where the bat couldn't get a lot of speed going, so in some tunnels and then right outside their den. And so the bats are like, oh, excuse me. And then they keep going, poor guys.
Okay, here's my last but probably my favorite thing that I learned. And this goes along with that previous episode where we learned that the bats are like, please get out of my space. Oh, my gosh. Stop. Was part of their conversational, their norms. This also gives. I'm totally anthropomorphizing bats now, because in 2014, a report came out that bats sometimes jam each other's sonar when they're competing to gain the advantage in foraging when they're in the air. So one bat may be like, ooh, I'm getting that thing. And the other bat sees it, and he's like, no, you're not. And he sends out this specific tone. And so scientists looked at them, they're like, are we seeing what we think we're seeing? That there's really a specialized jamming call. They are.
[00:07:43] Speaker A: So you're going for your juicy moth, and then somebody throws up, like, static, it's in your way, and you're going, I lost it. And then somebody else catches it. That's rude.
[00:07:52] Speaker B: Yeah. And the other guy probably doesn't actually catch it, but he blocks the first one from it. So Aaron Corcoran from the University of Maryland and William Connor, professor of biology at Wake Forest University, with a sponsorship of the National Science foundation. Ooh, you have to say the national science Foundation in your PBS voice.
[00:08:13] Speaker A: You do.
[00:08:14] Speaker B: They studied this to see. Did we just really see that? Is there a third vocalization that bats are making. And indeed there is. So we talked about their echolocation, their communication with each other, and now we know that they also have vocalizations for acoustic interference.
[00:08:33] Speaker A: Okay, so.
So then it's not, I'm gonna block you, and then I'm gonna get it. It's like you walked out of a bakery with a cupcake, and I slap it out of your hand so neither of us can have it.
[00:08:45] Speaker B: It kind of seems like that, and maybe it's because there is, like, a. An area that's rich in prey, and they're like, oh, no, I'm headed that way. Things. And they will do it to each other repeatedly, sometimes until one of them gives up. Oh, my gosh. Fine. And leaves.
[00:09:03] Speaker A: There's just two people screaming at each other in a room. My chips, my chips, my chips.
[00:09:08] Speaker B: Yes, yes. And those are the ones fighting over space when they get back to the den? I think so.
[00:09:14] Speaker A: You're touching me. Stop touching me. Oh, my God.
[00:09:18] Speaker B: Yeah. I think this research would have been kind of fun because it would be like, the bat version of, like, one of those housewife shows where there's just.
I've never watched them, actually. I just assume it's a lot of bickering. But to do this research, they went to the southwestern research station in Arizona and a high school parking lot in Animas, New Mexico.
[00:09:38] Speaker A: That's appropriate.
[00:09:39] Speaker B: Mm hmm. Yeah, it totally is. So the biologists recorded the bats in what they perceived as competitive moments with highly sensitive cameras and an array of ultrasonic microphones. And that allowed them to then put that together and match this new frequency with the behavior. Like, that's totally happening.
[00:10:02] Speaker A: You know, what's cool about that is in the summer here, depending on where you are, if you're, like, down by a river or something, there's lots of little brown bats, you know, flying around, and sometimes you might hear just, like, the tiniest little squeak. But with those microphones, it must be so noisy. Right?
[00:10:21] Speaker B: I do like the second test. The second test, to just verify their result, they lured wild bats into trying to capture moths that were on a really fine piece of fishing line.
So they lure them in. They're like food. And then they played what they presumed was the jamming call, and it caused the bats to miss the prey.
[00:10:45] Speaker A: Ooh.
[00:10:46] Speaker B: This phenomenon has only been observed as of the writing of that article in 2014. The interesting thing now is, do other echolocators do this? Do other bat species, do dolphins do this? I could definitely see some catty dolphins being like, nope, not today, buddy.
[00:11:05] Speaker A: Yeah. You can't hear that? You can't hear it. I hear it. You can't. Oh, yeah. No, that seems like. I think anything that has some sort of. Oh, they've gotta be.
[00:11:14] Speaker B: Yeah. So, to recap what we learned about bats today, sometimes they're beautiful and elegant creatures, but they are also jerks to each other who are sometimes a little uncoordinated.
[00:11:26] Speaker A: Oh, are we talking about the US government? Wait, no.
[00:11:32] Speaker B: Sorry.
I think that was too good. You had to take it.
[00:11:37] Speaker A: I did.
[00:11:39] Speaker B: So now we're getting up there. Bats have sort of entered the realm of rats and ants and fish.
[00:11:45] Speaker A: They have.
[00:11:46] Speaker B: We've accrued a few bat episodes now, I think. Cause I don't think that other one was our first bat topic.
[00:11:51] Speaker A: No. Cause I talked about fruit bats and how mom fruit bats teach their babies how to, like, find the cave and find the trees. That's right. I mean, they're easy to study. They're small. Some of them are cute. Some of them are not cute.
[00:12:04] Speaker B: No. Some of them are definitely very dracula smooshy faces.
[00:12:08] Speaker A: The pug of the bat world. I'm sorry.
[00:12:12] Speaker B: They totally are.
So that's been bat chat with trace and amy.
[00:12:19] Speaker A: Wow. I just love bat chat. I feel like I've learned so much, I wanna listen to it while it's nighttime. Hey, and you know what? You can do that. You can listen on your phone, wherever you are with whatever you prefer to listen to.
That didn't make any sense. But that's okay.
[00:12:35] Speaker B: Wherever you prefer to listen.
[00:12:37] Speaker A: Yeah, but Amy and I will catch you next time when we share more of everything you never knew you wanted to know, and I guarantee you will not be bored.
