SciShow Tangents - SciShow Tangents Classics - Bats

Episode Date: September 29, 2020

We're taking a short dirt nap this week in preparation for October's frightening festivities! Enjoy this classic, slightly spooky episode and join us next week as we kick off Monster Month!It'll be worth the wait, I promise!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Stefan: @itsmestefanchin Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links:[Poem]https://www.smithsonianmag.com/smart-news/these-pitcher-plants-call-bats-get-their-poo-180956014/https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2010.1141[Truth or Fail]Bats that spend time on the ground:http://news.cornell.edu/stories/2005/03/vampire-bats-keep-out-trouble-running-study-showshttps://www.ncbi.nlm.nih.gov/pubmed/16621953https://www.australiangeographic.com.au/blogs/creatura-blog/2018/01/why-fly-when-you-can-shuffle-the-lesser-short-tailed-bat-prefers-the-ground/Diurnal bats:https://www.nationalgeographic.com/animals/2018/11/daytime-bats-help-explain-nocturnal-evolution/https://blogs.plos.org/ecology/2017/06/29/bat-species-found-only-on-islands-in-trouble-worldwide/https://www.degruyter.com/view/j/mamm.ahead-of-print/mammalia-2017-0128/mammalia-2017-0128.xmlSuction cup bats:https://www.wired.com/2010/04/how-sucker-winged-bats-hang-on/[Fact Off]Bat & dolphin echolocation:https://evolutionnews.org/2012/05/tangling_the_tr/https://www.sciencemag.org/news/2010/01/hear-bats-and-whales-share-sonar-proteinhttps://www.cell.com/current-biology/fulltext/S0960-9822(09)02073-9https://www.nature.com/articles/nature12511https://blogs.scientificamerican.com/tetrapod-zoology/refined-fine-tuned-placental-mammal-family-tree/Moth echolocation blocker:https://www.sciencemag.org/news/2009/07/moths-block-bats-sonarhttp://science.sciencemag.org/content/325/5938/325?keytype=ref&siteid=sci&ijkey=GbDjRlkoHfRnYhttps://www.nationalgeographic.com/science/phenomena/2009/07/17/tiger-moths-jam-the-sonar-of-bats/http://jeb.biologists.org/content/214/14/2416[Ask the Science Couch]White-nose syndrome:https://www.biologicaldiversity.org/campaigns/bat_crisis_white-nose_syndrome/Q_and_A.htmlhttps://www.whitenosesyndrome.org/static-page/what-is-white-nose-syndromehttps://www.smithsonianmag.com/science-nature/how-bats-could-bounce-back-devastating-white-nose-syndrome-180969378/https://www.nature.com/articles/s41467-017-02441-zhttps://www.mdpi.com/2309-608X/4/2/48[Butt One More Thing]Bat guano gunpowder:https://tshaonline.org/handbook/online/articles/dkc09  

Can you feel it, dear listener, the sinister chill in the air? Can you hear the rasping call of the ghouls calling from their tombs? It can only mean one thing. Fear Month is almost upon us. And we have something sinister planned for you, but we don't want to give you too big of a shock. So this week, we're posting a rerun of a very lightly eerie episode, so you're better acclimated to the true terror that awaits you next week. Please enjoy this episode about bats and prepare yourself for what's to come. Ha ha ha ha ha ha ha ha!

Hello, welcome to SciShow Tangents, the likely competitive knowledge showcase starring some of those geniuses that make the YouTube series SciShow happen. This week joining me as always are Stefan Chin. Hello there. It's been a while since we recorded, so I actually haven't seen you in a while. How have things been going? Nothing's new. I'm still moving in. Oh, wow. Very slowly.

Like, take one thing out of the box each day. We're also joined by Sam Schultz. Hello. Who's got very blue hands right now. That was going to be my tagline. No, I don't have one. Oh, I didn't ask Stefan what his tagline was. Oh, channeling that big Zamboni energy.

Ooh, I don't like it. Yeah. Sam, sorry. That's okay. Let's start all over again. Hi, Sam. Hi, Hank. So, tell me about your tagline, then.

Very natural intro. Oh, we're going to leave the first one in. Oh, okay. My tagline is currently covered in blue paint for a secret reason we've also got sari riley hello hello i'm waiting for a prompt a question to answer sari what is your tagline yikes just just several yikes or just one oh just one y one yike. And I'm Hank Green. My tagline is all new skin. Our worst intro yet.

I think it was tight. Tight as a mofo right there. That was really together. Every week here on SciShow Tangents, we get together to try to one-up, amaze, and delight each other with science facts. We're playing for glory and also playing for Hank Bucks. I've had several people reach out on Twitter and they say to me,

you know, you should probably keep track of who's doing good in the Hank Bucks department. So maybe we should do this. Early on, there was a good reason not to. Yeah. Because we weren't doing them in order. Oh, now we are. Now we can. I think we'll probably be totally fine.

Okay, let's do it. We can figure out a way to do that. Okay. Yeah, I want people to be into the metagame of all of this. Mostly I'm scared that it'll be like very skewed in some way and we won't realize it. Oh, skewed towards me. Probably skewed towards Sam. Since the show is called SciShow Tangents, you might expect that we go off on some of those,

but we try to stay on topic. And if we go off on a tangent, if it is deemed to be unworthy, the rest of the team can force you to give up a hank buck for your bad tangent. Now, as always, we introduce this week's topic with a traditional science poem this week from Sari Reilly. There are plants shaped like pitchers with fluid within and digestive enzymes to break down what has been unlucky enough to fall into these traps, except for one species. It's perfect for naps. Its mammalian tenants get sleepy by day, need a safe haven to roost and keep predators away.

Whether they're flying solo or a mom-baby pair, cute woolly bats snuggle in and take care. Now you might ask, what's the plant get from it? Well, the bats pay their dues, and their currency is shit. Nitrogen-rich bat guano is a precious treat for a plant starved by poor soil that just wants to eat. So a bat and its toilet, what a friendship, what a team. And bat poop, I guess, is worth more than it seems. Ah, this week's topic is bats, not poop, not pitcher plants. I know. Could be a lot of different things.

Oh, mutualistic relationships. Not mutualistic relationships, but just generally bats. That's a good bat fact that you turned into a very good. Very good. Usually, Sari defines our topic for us. Do you have a what is a bat? What is a bat? What is a bat?

Are they all related to each other or are they? Did they ever convergently evolve? I don't actually know the answer to that question. They're all related to each other as far as i know yeah i think they're in an order called chiroptera do you know what their clade is i don't because i know what their clade is what's a clade a clade is a taxonomical subcategory okay basically i think it's a category within another taxonomical category but there's lots of different kinds of clades. But they are in the clade scrotifera, which is mammals with scrotums. Though we are not in scrotifera, which is a little confusing.

Why not? Is ours different? Ours is different. I think that our scrotums evolved separately from bat scrotums, but I'm not sure. I just know that we're not in scrotifera and bats are. So all scrotifera evolved from one ancient scrotum but i'm not sure i just know that we're not in scrotifera and bats are so all scrotifera evolved from one ancient scrotum correct i mean yeah i mean they definitely came from the genes contained in one ancient scrotum yes that's beautiful that's something poetic about it

uh but sorry i interrupt because i wanted to talk about scrotums does anybody want to charge me for that i don't think so i liked it yeah okay bats have scrotums part of the definition of a bout uh they also have they're the only mammal that actually flies so there are other mammals that can glide they have membranes between their limbs but bats have modified arms, that they can flap and fly through the air and don't just soar down like a flying squirrel or a colugo or something like that. And all bats have a common bat ancestor. As far as I know, yes. Papa Scroat, I think they called him.

And they're the second largest order of mammals, which I thought was interesting by number of species that they have. Wait, second largest? Yeah. I thought they were the largest. Yeah, I thought so too. Rodents, yeah. Oh, rodentia.

You're learning from the show. Yeah, right. And some of them eat insects or fruit. Like those are the two main categories of bat food. And blood. Yeah, what about the drinking blood? Yeah, then they're vampire bats who are off in their own corner and they gave all other bats a really bad name basically right

i think also bats carry a lot of diseases and especially like viruses and stuff that are transmissible to humans which probably helped spread the vampire myth okay so we know what bats are yes they're cute too i think they are. Yes. They're cute, too. I think they're really cute. Yes, Sam defined bats. They're cute. I already did. They're fuzzy, cute fly balls.

Are even the big ones cute? Yeah. Like the two to three meter wingspans? Like a flying fox? Yeah. Yeah, I would be free to be a flying fox. And now, it is time for... One of our panelists has prepared three science facts for our education and enjoyment.

One science fact. Hopefully you've listened to previous episodes and know how this segment works already. So there's two fake facts, one true fact. And the other panelists have to figure out either by luck or wild guess which is the true fact. If we do, we get a Hank book. If we don't, then Stefan gets that Hank Buck. Stefan, what are your bat facts? Fact number one. The lesser short-tailed bat is

the only species of bat that we know of that has evolved flightlessness. It lives in New Zealand and crawls around on all fours foraging for food and chews into trees to create little burrows for itself. Flightless bat! If that's not real, I'm gonna give you a hank buck anyway. I'll take it. Fact number two. While the vast majority of bats are nocturnal, the Simone flying fox is the only bat that exhibits, quote, strong diurnal proclivities,

meaning that they are active and forage during the daytime. Okay. And number three. Weird. While most bats grab onto things with their feet and roost upside down, the bats in the genus Thyroptera are one of two bat genera

that roost head up, but it's the only one that uses suction from little cups on its hands and feet to hang onto leaves so it can do that. That's cute.

So we've got flightless bats that burrow into trees, the daytime bat, and suction bat that roosts head up. Oh, man. There are so many different kinds of bats. So, like, any of these seem totally plausible.

I am a big fan of the flightless bat, though, because I would never have thought of a flightless bat existing. But, like, it totally could. It makes sense. Would you say it was from New Zealand or something? There's also lots of flightless birds down there. The diurnal bat seems the fakest to me. Because it feels like there'd be lots of diurnal bats. Yeah. Because like not all bats are nocturnal, I think, which like by definition means that some of them have to be diurnal. Also, not all bats eat insects.

So like there are bats that eat fruit and you don't need to look for fruit at night necessarily. Right. So are bats mostly nocturnal because that's when the bugs are out? I don't know. Why? Because it's not like they need to worry about predators too much, except for like, I guess, birds of prey. Because it's going to be hard to catch a bat. I am going to go for the lesser short-tailed bat.

The bat that does not fly. A flightless bat. I'm going to do suction cup bat also because I love it. I pick suction cup bat too. Okay. It was the suction cup bat. So the Simone flying fox is mostly diurnal. And there are a few species that we know of that fly around during the day.

But there's only like four species total. And they all live on islands where there are not predatory birds i think the leading hypothesis for why bats became nocturnal in the first place is that when they were evolved first evolving they had to compete with predatory like hawks and right owls and things who are probably way way way better at flying than they are yeah right okay and i typed in flightless bat into Google and I got the New Zealand lesser short-tailed bat. Mm-hmm. But it's not flightless.

It's not flightless. It just crawls around a lot. Yes. It's just lazy. Yeah. No. I don't know why it does it, but that and the common vampire bat both spend a lot of their time on all fours. Walking around? Walking around. Lazy makes sense

to me for that because it probably takes a lot of energy to fly. Yeah, but you go much faster than when you're just walking around with your big wings. And it's like harder to run around when you have wing arms. Yeah, like your hands are just giant flaps of skin. You're walking on like your

tops of your hands or something. Yeah, just like one knuckle, right? Because their wings are their digits spread out. But yeah, so those bats still fly. The New Zealand one does actually chew into trees to make little burrows for itself, whereas most bats roost. And these ones actually roost most of the time. Just sometimes they chew into a tree. So then the true thing was about the suction cups.

And there are two genuses, Thyroptera, which are the disc-winged bats, but they use suction to stick onto leaves. And the other genus, Myzopoda, are called sucker-footed bats, but they don't use suction. They secrete a sticky, wet fluid from their pads. Oh, cool. They just, like, have stuff that leaks out of their fingers. I'm glad that's not me. Well, you could climb stuff, though. But, like, touching things.

Yeah, that would be a struggle. Typing would be hard. You'd have to wear gloves. Just wear gloves, yeah. And then you take your glove off at the end of the day and be like, look at all my goop that has been accumulating inside of my glove. You know, when you go to the bathroom, you change your glove. Right.

I like this. I like this speculative universe in which everybody has to change gloves every 30 minutes. Everyone just has really sticky hands. Because we evolved from sticky people. All right. Next up is the fact off. But first, a word from our sponsors. Now get ready for the Fact Off.

Two panelists bring science facts. That was a big one. Bring science facts to present to the others in an attempt to blow their minds. The presentees each have a hank buck to award the fact they like the most. So you award it to the one who blew your mind the most. It's going to be me because it's me versus Sam. I'm not saying that Sam. I'm just saying it's going to be me. That was balanced.

I heard what you said. You don't have the Dracula voice either to make it funny. It's me against Sam. I wouldn't stand a chance against Dracula. It's me against Sam. And I'm sure that we have equal chances of winning. The person who's going to go first is the one who most recently gave blood. It's been a long time. It's been recently gave blood. It's been a long time.

It's been a long time. It's been a long time for me, too. I give blood to my doctor, like, once every—in fact, I'm scheduled to do it today, and I didn't, but I should have. Regularly. But this is, like, to the blood bank. Yeah, this is to the people who need it, the vampires. I think I was in high school, maybe. Oh, okay.

It's been a long time. Oh, all right. Well, it was definitely me then. I got the good blood. I got the universal donor blood,. It's been a long time. Oh, all right. Well, it was definitely me then. I got the good blood. I got the universal donor blood, so I feel bad not doing it. Yeah, makes sense. So I probably gave birth the last, like, two, three years ago. I have B positive, which is a nice little reminder for me.

I do, too. And my dad would always make jokes about it because I'm, like, not a super optimistic person all the time. He'd just be like, B positive, Siri. And you'd be like, be positive, Siri. And you be like, go to your room, dad. Yeah, I'm being an angsty teen right now. I don't need that. Alright, so I guess

that means I go first. Everybody, you know about dolphins, right? Uh-huh. Yep. They are like bats in one way, but almost no other ways. We talked a little bit about how bats are in scrotifera, but it turns out dolphins are also, weirdly enough, in scrotifera. What? What a stupid group.

They don't have scrotums. Wait, wait. But their ancestors do. They used to have a scrotum. They look so funny. Were they external? Yeah. Yeah.

Well, their ancestors were like cows and stuff, like horses and I don't know. Did they just get bitten off one generation? No. It wasn't good for swimming. We need to do an episode about evolution apparently. We did one. I know. Yeah.

Camels, pigs, ruminants, and whales are all sort of like together. Cool. And so those things have scrotums. But the dolphins, that would be really uncomfortable if they're just hanging out flopping in the— Yeah. Anyway, that's not what my fact is about. It's not real. So they are somewhat closely related.

Like they're more closely related to each other than they are to us, for example. But they are very different things. Like it's a tiny fuzzy thing that flies in the air versus a big, not fuzzy thing that swims in the oceans and mostly just the oceans. But they do have this thing in common where they both echolocate. They see with sounds

and they do it very efficiently and effectively. And this is a thing that evolved and it evolved from two animals that like evolved it independently of each other. But since they're fairly closely related animals, it turns out they evolved this in exactly the same biochemical way. So usually convergent evolution is a thing that happens when like, you know, a bat and a bird both have wings, but they got their wings in totally separate ways. Like a bird's wing is the whole arm. A bat's wing is just the fingers

is just a separate thing. But in this case, the same protein Preston in the ear has the same mutations in it that makes it different from our Preston in dolphins as it does in bats. our Preston, in dolphins as it does in bats. They have the same different genes, but they evolved those different genes entirely separately. It's one of the best cases of convergent molecular evolution there is, and it was only recently discovered, and I find it very cool. That is very cool. What does the gene specifically do? Does it just like...

It codes for like a little hair in your ear that hears better. Basically, it's a change that lets them hear more sensitively. That's interesting to me because dolphins also don't have big ears to channel the sound in. Right. Yeah. So the fact that they have the same mutation and that functions underwater and above water and without ear flaps. Like the ear area. Yeah. So the fact that they have the same mutation and that functions underwater and above water and without ear flaps. In like the ear area.

Yeah. Well, I assume dolphins have ears, but do they open to the outside world? Because I know like there's whales that have like internal ears. I think it's whales. But then sound is transmitted through their jaw. There's like a material in their jaw that can transmit the sound to their ear canal. Dolphins do have a tiny, tiny little ear hole. Okay.

It is pretty much invisible unless you're looking for it. But that is where the sound goes back in. Yeah. And that's where their little, their Preston hairs are. There are 14 points of mutation that they share with bats. And they all changed in exactly the same way. Whenever my son walks into a place that echoes, like it sounds different because it's got some reverb quality,

he goes, bop, bop, bop, bop. And I'm like, you are echolocating, aren't you? Maybe he's got the little ears. It's super cute. Like, you walk into a tunnel and he's like, bop. Bop. He's gonna catch some bugs.

Yeah. So that's my fact. Good. Hit me, Sam. All right, so, bats echolocate to find food? Yeah. I think.

All right. Bugs. And one thing that they eat, moths. And this is a conjecture on my part, but a moth seems like a pretty good food for a bat because they're big and they don't seem like they fly so great. Yeah. And they're very easily confused by lots of stuff, including light.

So they can just swoop around and eat them. But there are some types of moths who have learned to fight back against bats. So there's a family of moths called the tiger moth family, and they make clicking sounds by vibrating membranes inside of them scientists have known about this for a long time and that a lot of tiger moths are poisonous and so they click to alert bats not to eat them because they are poisonous but there's a type of tiger moth called the bertholdia trigona which has way louder clicks and isn't poisonous. And nobody could figure out why until 2009. So in 2009, they tied a bunch of moths to the ceiling with like fishing line and they were

just dangling down and they let bats out into this room to eat the moths. And some of the moths could make the sound and some of them had been altered so that they could not click. I'm sure in a very humane way. Yeah, probably not just with a big needle poked through. So what they found was that the bats caught the non-clicking moths 400% more often than they caught the clicking moths. And the ones trying to catch clicking moths, the bats trying to catch clicking moths, looked confused and hesitant to try to catch the moth.

So what they determined after taking a closer look was that the moths could make 4,500 clicks per second, which basically made like a curtain of sound that the bats got like garbled feedback from their echolocation. It jammed the radar. Yeah, totally. So they couldn't tell where the moth was, so they would like swoop into like thin air

and not be able to grab the moth. That's it. That's amazing. So cool. I didn't know all that. Wow. I thought I was a shoo-in, but now I'm not so sure.

I also, we did a SciShow on various moth strategies for not getting eaten by bats, and it's also potentially why they're fuzzy. It's because the echolocation bounces back less efficiently. It less sound foam. Yeah. Cool.

Sound foam for moths. So moths have just devoted their lives to not being eaten by bats. Which is probably a pretty good strategy for slow moving, juicy bit of food that lives in the air. How do they make the clicks? Like, is it, do you know anything about the organ that does that? I couldn't find anything that described it super, it just said membranes inside of them. Clicky membrane.

And so the poisonous ones make a lot softer clicks that the bats avoid. The louder ones, the bats don't avoid. So that's why they were like, what's going on here? I mean, my thought would be like, they're just trying to pretend, like, I'm also clicky yeah i i'm poisonous like a like a uh a mimic and there are there are non-poisonous ones that do that too okay these ones just like they're so

loud you can hear them without any kind of like special equipment you can just hear them flying around in fields all right those were two very good. I have no idea what I would choose, but me, so. I'm going to give mine to Sam because that was more mind-blowing to me. Just like learning about the curtain, the sound curtain.

It's really good. It is. They're jamming the radar of a convergent molecular evolution. I know. 14 points. Do have a good probability.

Yeah. Well, mine's that probability too, right? Sam's is less mind-blowing from a statistical standpoint, but the mechanism is more mind-blowing. Memories. So I'm going to give it to Sam. No! I was very satisfyingly mind-blown by both.

Okay. Yes. But I got more points. i will survive it is now time to ask the science couch where we ask listener questions to our couch of finely honed scientific minds at gannon 188 and at biology alex ask is there any cure for the fungus aka white nose syndrome that's wiping out the United States Northeast population of bat. You're looking at me like I have any idea. I have no idea.

I got nothing. Have you heard of white nose syndrome before? Yeah, it's definitely a problem. And like the question has been, in my understanding, is this just a really bad pathogen or is there some human cause that is making it worse,

like pesticides or habitat loss or something that is making it more common for it to be spread more easily and i don't know the answer to that i saw a picture and it looks a lot like moldy nose yeah it's like you get a fungus face fungus and mold yeah are those the same thing yeah mold is a fungus so yeah it is a fungus I don't know if we're confused about how or why it spreads, but it started in winter 2006 in Albany, New York. As far as we know, it was probably other places, too. But that was the first documented case of it where they found dead bats with white fuzz around their nose. It's a fungus called. Oh, gosh, I couldn't find a pronunciation. So this is just me doing my best with my biology knowledge, pseudogymnoascus destructans. Ooh, that's a bad name. Yeah. I don't want that. This one bad. And it attacks the skin of bats. So that's why it shows up around their nose, because that's not where there is fuzzy, but it also attacks their wing tissue, anywhere that is exposed skin. and essentially what it does is like this attack on their immune system makes them wake up when they should be hibernating so during

the winter times during the day times and use their fat reserves when like they should be energy so it destroys their tissue and then leads to really malnourished looking bats. Really, their wings like tighten up for some reason. I think it's like whatever makes it flexible maybe gets destroyed. I watched a video and like a woman was pulling on a bat wing, which would normally stay extended and it like contracted really quickly. Why does it wake them up? Because they're in pain or something or just messes them up? I think so.

I think it like messes up something with their internal systems. I don't know exactly how it attacks them, but it's like a bad infection. It'd be like getting a bad cold, but fungus in your body, I guess, which is not the same as a cold. One source that I was reading called it one of the worst wildlife diseases in North America. So since winter 2006, it's killed over 6.7 million bats by some estimates um which is a lot yeah and it can kill 70 to 90 percent of bats in an infected uh i love this word hibernaculum which is uh the place where bats gather to all hibernate in the group so like it's a it's a hibernaculum of bats do they hibernaculate

oh caves probably yeah general bat places okay they don't have a special no special place a lot of caves yeah and this is you can see maps of where this is found it's mostly in the northeast u.s mostly in can Canada, like that general region. And they're finding it more and more western in the United States. And we've actually found this fungus infecting bats in other countries, like several other European countries and I think in China. But in the U.S., it's extremely deadly for some reason. extremely deadly for some reason. And we think it was transported over here by humans, not by bats, because there's no way for a bat to migrate across the ocean in that way. So it was probably like a human in a cave, got the fungus on them, spread it to a different cave. And just like the colonizers,

we have infected the bat population right now, decimating them. So that is white-nose syndrome. We're trying to figure out possible cures for it. And a lot of the research that I found is pretty, like the beginning stages of it and pretty recent. So one main avenue is like people studying the DNA of this fungus. And they found that, one, it needs cold to grow. Like something about its genetic makeup makes it require cold. So we should heat the earth up. Oh, perfect.

Should we warm the planet? Global. How would we do that? Good idea, but I need some avenues. At least the bats are going to be. So they're not entirely sure what to do with that information, but also during the same genetic research where they discovered that it needs cold to grow, they also found that it's missing the repair mechanisms for DNA when it's damaged by UV light. So I don't know. In all of our bodies, we have a bunch of cellular molecular biology mechanisms that like our DNA is constantly being damaged damaged by uv light having mutations and then it

goes back and fixes it and so this fungus doesn't have it so so we need to shine the light on the bats yeah they're trying to figure out a way i think they called it a uv tunnel or something like constructing those at the entrance to caves have to like crawl through the uv light yeah or like they fly through it and get blasted by UV light, which doesn't harm the bats because they have the repair mechanism, but the fungus doesn't. But it sounds extremely elaborate. Like you need a lot of timing. That would be good for maybe one cave at a time. They also found that there is a fungal compound that inhibits the growth of p-destructins they had i'm guessing like dishes

of p-destructins and then vape like sprayed this vapor this mushroom vapor on them vaping that truffle butter so we either so okay so our solutions are global warming just UV tunnels, and the bats have to vape. That sounds great for the bats. Yeah, they can like tan and vape. Pretty cool. And one professor has tested bat vapes, but he called it a bat fogger instead. A little loser.

I think he used some sort of antifungal volatile organic compound, which is what this mushroom alcohol falls into. So some sort of chemical. I'm not sure if it was this exact one and sprayed a bunch of fog into an abandoned railway tunnel where bats roost. And the just the numbers were higher than they expected. Like this was a colony that they'd known was infected with white nose syndrome. It had been decimated in years past, and it was like slightly higher than they expected it to be. So maybe it helped. We're not sure. But it doesn't seem to be something that's going away on its own. Like I haven't heard as much about white nose syndrome as I did like in 2011, I feel like. But that's just because we got tired

of talking about it, not because the problem's gone away. So the people who are studying these bats and studying white nose syndrome have also just been tracking numbers of like population numbers to see what is happening and what, where they have to concentrate their efforts. And it seems like certain colonies are rebounding by themselves. So like to give you a sense of the scale, one that they were monitoring had about 90 adult bats in 2010. And then in 2018, when the article I'm reading is published, it rebounded to 200. And they're not entirely sure why. Like, is some sort of natural selection happening where maybe bats that are more resistant to the fungus and this disease are surviving and passing on the genes that help them? Or is it behavioral avoidance of

sick bats like are they learning some sort of behavioral trait are they i don't know is the just going to lay out in the sun yeah being like what if we just like put a uv light in the cave and be like if you guys want to use this you can just imagine leaving little presents in each of the bat cave it's like a little UV lamp, a little vape pen. Here you go. Space heater. Yeah, space heater. Do with it what you will.

So, yeah. So it is like a very intense, very devastating thing. And people are worried about the bats. And it like sucks that it was probably human caused. Right. And so humans want to try and fix it but epidemics happen in nature all the time and species adapt or bounce back or don't go extinct so something's gonna happen oh no i'll go shine lights on bats yeah sam's got a new job

if you want to ask the Science Couch, you can do that by following us on Twitter at SciShow Tangents, where we will tweet out the topics for each episode every week. All right, so it looks as if I lost. Sarah, you've got two points. Thank you.

Oh, that's not a winning? Oh, no. No, it's not. Stefan, you've got one point. Sam. Yeah? Pulling out the win got one point. Sam. Yeah? Pulling out the win with three Hank Bucks. How?

I should have thought about this. Oh, I know how. Yeah. Oh, one plus two. Sam, I don't trust you to tally up all our scores now. You better build a spreadsheet so I can check your math. All right. If you like this show and you want to help us out, it is super easy to do that.

You can leave us a review wherever you listen. That's going to help us know what you like about the show. And also other people will know that too. Second, you can tweet out your favorite moment from this episode. I love it when I see those. And finally, if you want to show your love for SciShow Tangents, tell people about us. Thank you for joining us today. I have been Hank Green.

I've been Sarah Riley. I've been Stefan Schitt. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and WNYC Studios. It's produced by all of us and Caitlin Hoffmeister. Our art is by Hiroko Matsushima and our sound design is by Joseph Tuna Medish. Our social media organizer is Victoria Bongiorno and we couldn't make any

of this stuff happen without our patrons on Patreon. Thank you! And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. Is it about bat poop? It is about bat poop. All my facts are about bat poop. They got good poop. They got great poop. Bat guano has a really high nitrogen content, specifically compounds called nitrates, which

if you put them through a couple synthesis process, can be turned into things like fertilizer, but also gunpowder. And so at times, like this particular one is a civil war. When supply chains were cut off to the Confederacy, they would go to bat caves, mine a bunch of bat poop, put them in kilns, and create gunpowder from poop. Wow.

So we killed each other with bat poop. Yeah. Leave it to humans. Everything is chemicals. It's the ingenuity of a bloodthirsty human being. Thank you.