From the Vault: Life in the Hypogean World, Part 3

Published Mar 20, 2025, 10:00 AM

We are creatures of the epigean world: the world of light on Earth’s surface. But there is another world – a world beneath the surface. In this classic episode of Stuff to Blow Your Mind, Robert and Joe venture into the world of cave biology or biospeleology. (part 3 of 4, originally published 3/12/2024)

Hey, you welcome to Stuff to Blow your Mind. My name is Robert Lamb, and Hey, we were going to do our Hunters of the Dark Ocean Part two today, but Joe is outsick, so we're gonna come back in and continue that series on Tuesday. But don't worry, we should be back tomorrow with a brand new episode of Weird House Cinema. So instead we're going to go ahead and air the next Vault episode in the Life in the Hypogean World series. This is going to be part three. It originally published three twelve, twenty twenty four. Let's dive right in.

Welcome to Stuff to Blow Your Mind, the production of iHeartRadio.

Hey you welcome to Stuff to Blow your Mind. My name is Robert Lamb.

And I m Joe McCormick, and we're back with part three of our series on cave biology and cave environments. Let's see what did we talk about in the last two episodes of the series. Obviously, if you haven't listened to those already, maybe you should go back and check those out first, But if you'd rather just jump in here, that's okay too. In the previous parts, we talked about some of the common characteristics of cave environments and especially in ways that would affect animal life. We talked about the presence of guano in some caves, bat dropping guano as sort of the base of a food chain, the equivalent of sunlight to the outside world to the inside of the cave. And we also talked about some specific cave organisms, such as the blind Mexican cavefish, about which there has been a lot of research research on how exactly these fish evolve. These various populations of fish in northeastern Mexican caves evolved to lose their sight and lose the pigment and their flight and so forth, Why that evolutionary pathway takes place in the cave environment and so forth.

Yeah, so we're gonna so we've established to a degree, the cave environment, the cave ecosystem. We've talked about characteristics, We've talked about some individual species, and we're going to kind of continue that trend here. We're going to talk about some more specific organisms that make their homes in the cave environment, or we're going to look at creatures that dip into that ecosystem, dip into that biomass that is already living in the cave.

All right, Well, I think I'm going to kick things off today with a full cave entry.

All right, let's do it.

No, no halfway in on this one.

This is an obligate cave dweller.

Right, So according to one source I was reading, actually this has been claimed as the first animal to be recognized as permanently adapted to a cave environment. I couldn't verify that priority, but that's the claim at least, so that may be true. This animal is an aquatic cave salamander called the oulm, also known as the proteus. Scientific name proteus. I think you would say Anguinus proteus a n g ui in us. The ulm occupies underground waterways in Europe, especially karst caves of the Dynaric Mountains, which is the region of the Balkans along the eastern coast of the Adriatic Sea, so you can think east of Italy, across the Adriatic from Italy. And I was looking around for some good sources on the history of human knowledge of this animal, because I know the first writings about it were very interesting. And I came across a paper in the Journal of Cave and Karste studies from twenty twenty one by Evo Lucic called an underworld tailored to tourists, a dragon, a photomodel, and a bioindicator. And Lucik does an interesting thing in this article. It's not really focused on biology. Instead, he's sort of focused on the history of how this animal has been perceived and categorized by the media and the public. So the earliest writings about the ulm are sort of famous. There is an account in the writing of a seventeenth century author and natural historian named Johann Weikard von Valvasor VLVASR. Valvasor, who was from the region then known as Carneola what is today Slovenia, and Valvasor famously published a sort of encyclopedia of the region known as the Glory of the Duchy of Carniola. And because of the striking geology of this region with the kar the caves, the work did contain some investigations of the local k Its caves, its associated culture and life. So here, summarizing Valvasor, Lucik says that around sixteen eighty nine, Valvasore reported that he had heard stories from peasants in a region known as the Vernica that they had seen a baby dragon in the local water source known as the Bayliss Spring, and the people who knew this spring said that the water would flow from it reliably twice a day, once around midnight and once again around nine am. And this apparently was linked to some kind of belief in an underground dragon, which, when it became angry, would spit out water and perhaps one of its own young One of the peasants that Valvasore spoke to said he had seen three young dragons spit up in this way by the spring, and a local mail carrier claimed that at one point he took one of the baby dragons home with him and it was about as big as his hand and looked like a lizard.

And it does sort of look like a lizard, but I would say a little bit lizard, a little bit vampire, princess, little bit just you know, it depends what the lightings like. But yeah, it's this long, slender organism with this elongated head and these wonderfully dainty little limbs.

Yeah, so it is a salamanderin form. It has a kind of flat, almost elongated I was gonna say shovel shaped head, but it's not really shovel shaped. It's more kind of if you look down from above, the head is sort of crocodile head shaped, but yeah, it is a kind of flat head. It has frilly red gills extending out from the base of its head around its neck. It has yeah, as you say, delicate little limbs that don't look like you know, they would do a whole lot, but it can use them. And otherwise the body is like a long kind of white snake. It is a translucent, white, fleshy skin going in this snakelike shape. I've heard some authors say that if you look at it closely, you can actually sort of see its organs through its skin, like they'll the light can sort of penetrate it and you can see its insides. And you can look up pictures of the ulm online. They're they're pretty readily accessible. It's it's a creepy looking organism. I mean, it does in some of these photos it almost seems to kind of glow because I guess of the maybe low light conditions in which it is being photographed, and it's very pale skin is like reflecting a lot of light.

Yeah, I mean, I guess, kind of creepy, but also just haunting, almost kind of elfin in its in its appearance, you know, like this is a being from another world and it's its body and form, it's is entirely alien to us.

And it's funny. So the rest of this paper by Lucik really emphasizes the extent to which sort of mythological themes have permeated the public understanding of this creature and are even in some ways still prevalent because of the ways that this creature is marketed by the local cave systems as tourist attraction, and those that marketing places a lot of emphasis on mythological themes, like referring to it as a dragon. However, of course, over the following generations after Valvasor, a scientific view of this creature began to take shape. That it was not a dragon, of course, but an amphibian, an amphibian that lived in waterways underneath the earth, which could explain why specimens were sometimes disgorged from a spring or cave opening after heavy rains. And so I wanted to get a scientific perspective on this creature, and I dug up a paper that I thought was interesting. This was a paper published in the Journal of Zoology in twenty twenty by belaws, Lwarn and Hertzcheg called extreme site fidelity of the oulm Proteus anguinus revealed by a long term capture mark recapture study. So I'm going to try to do a bit of a recap of what this paper does in reviewing some of the main biological characteristicks of this animal and then discuss the findings of their specific experiment. One thing they do, and this is important to do, I think in the episodes of this series is they remind us about the common characteristics of cave habitats. There can be some variation between different caves, but cave ecosystems are usually going to be shaped by a reduction or total absence of light that changes a lot about how organisms survive food scarcity. This is common to a lot of caves because, as you might recall other organisms we talked about, like the blind Mexican cavefish, seem to have adapted to their environment by having lower nutritional or energy needs than their surface surface variant cousins, that they need less food to survive, and they have to adapt to be this way. Because there's less food in a cave. Another thing the authors identify is what they call simplified communities. I looked this up to make sure I was understanding it right, So I found one other paper discussing this concept in the journal Bioscience, And according to their definition, simplification seems to be a quote reduction in niche diversity. So I think that means, you know, fewer ways for organisms to specialize, which kind of makes sense within a cave.

Yeah.

And then finally they mention that the cave environments are usually shaped by the fact that there the cave environment is a major buffer against changes in climate and other environmental variations. So living in a deep cave largely removes the variation of things like the night day cycle, seasonal changes to weather, and so forth. So a cave environment, though some changes can still come. And obviously if you're living in an underground waterway, like changes in water flow are possible, like heavy rains could still cause you know, increasing currents in the in the waterway and so forth. But there are going to be fewer cyclical, seasonal day, night, and other environmental changes in a cave than there are outside.

You mean, of course, you also might want to throw in seasonal habitation by certain organisms such as bats or historically things like a cave bear. But even then, the deeper into the cave you get, you could potentially be even further removed from the influence of sad organisms.

Right, And so the authors say, as several authors we've looked at have mentioned this, that the evolutionary ecology of caves is kind of hard to study for maybe obvious reasons, like aquatic caves especially are kind of hard to access, they require difficult diving and so forth. And they say that in the continent of Europe, vertebrates that are fully adapted to cave life are actually somewhat rare. There are more species that might go in and out of caves, but the ones that are the full on troglobions, the fully adapted to cave organisms, that there are not a whole lot of those. But one of the best known exceptions is the ome. It is not only a fully cave adapted organism, it is the largest cave dwelling vertebrate on Earth. The authors cite a couple of studies from Boulog in nineteen ninety four and Tronte in two thousand and seven to suggest that the ancestors of the OLM probably colonized caves somewhere between eight point eight and twenty million years ago. All known populations except for one, have regressed eyes and lack pigment in their bodies, so they appear eyeless and pale or translucent. The one accepted population is in a cave system in southeast Slovenia.

There's one called the Black Ome. I remember running across and it stuck with me because that sounds like such a like a death metal olme. Yeah, in your European gaverns.

But apparently just the difference is for some reason, this is the one population that has retained its pigment within the cave if they are top predators, which is kind of funny because when you look at them, they don't look like top predators. They look kind of unassuming, maybe creepy, but you know, they don't look scary. If that distinction makes sense.

Yeah, I guess it comes down to again, how scary do you have to be in order to be the top predator in a cave ecosystem where again, you have you do have food chain, you do have a certain amount of biomass available, but it is, it's all niche, it's reduced, so you're not going to have these enormous organisms. You know, everything's going to be on a smaller, hungrier, and more versatile scale.

Yeah, totally. And to be clear, I mean I'm not saying I actually think scariness is a biological indicator of whether you're a top predator or not. But you know, it's just the intuitions they don't seem to match. But they are the top predator in their cave environments. They prey on small animals like cave shrimp, snails, little insects, and they have no natural predators of their own, so there's nothing they have to normally watch out for preying on them there. They're the top of the pyramid because they have no predators. There's a part later in this paper where the authors observe that the olmuh do not seem to engage in hiding behaviors that they observed. At least they said it's possible that some olms are like hide back in cracks and crevices that they were never able to access on their dives, so you know, they couldn't locate them back there. But the ones they saw float out in the open, maintaining their place within the current of the cave waterway. Like you know, they're just not worried about that. They don't have to go hide. Now another way in which our naive intuitions about what it means to be a top predator can be violated. You might hear top predator and you think voracious appetite. You know, they're they're eating a lot, eating everything around them.

No.

Actually, the ome is famous for having an incredibly incredibly elastic energy needs. Like it it can survive five years apparently without food and can avoid starvation, so it can go into very low energy mode, can maintain a low metabolism, and can go for a long time without food.

Yeah yeah, because again the reduced availability of prey and a given environment, you need to be able to really stretch out those the spaces between meal times.

It's noted that they are neotonic, meaning they retain juvenile features into adulthood, and there's some other salamander species that do this as well. They can tolerate water with very little dissolved oxygen in it, so they have low food energy needs and low oxygen needs. And while they are blind to light. They do have a number of compensating sense mechanisms. The authors mention one of them is what's known as raotaxis. Raeotaxis is the ability to sense the direction of flow within the water, and then that's also paired with a behavioral instinct that causes the salamander to turn to orient its body facing into the water flow. And this is a common way for fish and other aquatic organisms to remain stationary rather than drifting away with water currents. They also use other senses than site. They have underwater hearing, they use their sense of smell or old faction, and they appear to have a magnetic sensoryability as well, which may help them orient with respect to Earth's magnetic field, possibly useful for orientation and navigation. As I said, the ulme has very restricted food needs like some other troglobiants we've discussed. You remember the blind Mexican cave fish had very low food needs compared to its surface variant cousin. They have what the authors call extreme life history adaptations, meaning their life just appears to sort of go in slow motion compared to salamanders you might on the surface. So I was looking up the maximum life span of surface amphibians, and of course that varies, but you know, on average it's going to be more in the range of ten to twenty years for large amphibians that live on the surface. The olem is thought to live for one hundred years or more, with females only reproducing once every twelve and a half years roughly, So that is incredibly long life for an amphibian, incredibly long in between mating and reproduction. So this experiment tried to study the behavior of the olm, especially the movement and migratory patterns of the olm, by using a capture, mark and recapture method, so you know, they'd catch one, they'd market, and then they would come back and see if they could capture the same ones again later note where they were relative to the original capture and so forth. Specifically, they were studying an eastern Herzegovinian population and the authors found what they called extra sdream site fidelity. Most of the creatures that they captured had barely moved since the years before. The average distance was about five meters from the original capture location a year before, and they also did multiple interval studies, so like capturing them at different times, and then checking up on them again. They found that moving distance was not correlated with the time since capture. So for a lot of species you might expect that the longer you go in between captures, the farther away from their original location they might have moved. In these salamanders, not the case. The longer you go in between captures it does not, on average affect how far away they are from the first time. So the question is why do they move so little? There could be a number of answers here, and the authors say, to be fair extreme site fidelity the extreme site fidelity of these salamanders is not necessarily extreme among amphibians. There are also some surface amphibians that may have very limited movement ranges. The authors could not find any reason based on the environment itself that would limit movement. In other words, there were no like gaps in the movement patterns that would indicate environmental features they were trying to avoid, and so they say their best guess is that this hyper sedentary lifestyle is probably related to energy constraints. The author's right quote, We can only speculate that animals feeding on a very low food supply and as consequence resistant to starvation, reproducing sporadically. Again, females reproducing on average only once in twelve point five years and living for a century, are very energy cautious and limit their movements to the minimum. It's a different kind of animal life to imagine, isn't it like an animal that to be clear, it's not incapable of moving quickly, like if you try to capture one and it has to perform orm an evasive maneuver essentially like it's trying to get away from you. They can move quickly. It just seems like undisturbed in their natural environment. If you use the capture recapture method, they haven't moved much after a year, after two years, and so on.

Wow.

The author is also note I thought this was interesting that I don't know exactly what to make of it, But they say that they have never seen a dead individual. Kind of interesting.

H Yeah. I mean, obviously we're dealing with creatures that are, like we said, difficult to observe anyway, and you know, we can't count out various other organisms that would then scavenge a dead one. We also have to take into account, you know, the movements of the waters that have at least historically been attributed to ones occasionally washing out and so forth. And even if one didn't wash out all the way to where humans could have observed them, it might wash them out to where other organisms would have a shot at scavenging them. But still it's an interesting tid bit.

Yeah, yeah, yeah. To be clear, I don't think they meant like humans have never observed a dead one obviously. I think they mean like in the in the region where they're looking at the live ones, they've never seen a dead one there, right right, yeah.

Yeah, And like I said, that could be because it is they do get periodically fleshed out I'm guessing, or yeah, scavengers of one sort or another.

The author is add a conservation note in their paper, which is that the extreme site fidelity of the of the olm makes it quite vulnerable to water pollution. You know, it changes to water quality, especially like if it can't I think, if it can't really migrate very effectively to get to a place where there's better water, it's more vulnerable to changes in water quality locally.

Though.

Vulnerability to water pollution I think is also true of many surface amphibians who are especially vulnerable because of the permeability of their skin. So yeah, another reason why, I mean not like we needed that many more reasons why water pollution is a bad thing. But here's another one. But final note, if you haven't seen a picture of the olm, you should look this one up. You want to see this flesh.

Oh yeah, absolutely, it's a.

Very it's a very Cronenberg biodesign.

Yeah, they're like I say, they're a little creepy, a little cute. They're very unique. All right. I want to get into a topic here that that came up early on in my research and a paper that came up pretty early on in researching these episodes, and it has to do with intraguilled predation. That's the killing and eating of potential competitors within an ecosystem, which is apparently a pretty big deal in the food chain of the Hypogean world. So, as we discussed in previous episodes and specifically in the last episode, you know, bat guano is kind of an alternative sunlight that forms sort of the base of the subtrain in Easystem a lot of the times as bats roost in the cave and defecate, thus bringing new resources for various organisms to feed on, which in turn feed other consumers. And as discussed in a twenty twenty one paper published in Scientific Reports by Param Mutchova at all quote, the food web in a subterranean ecosystem is driven by intragild predation. So in this paper they drive home some of what we discussed last time. That quote. Detritus based food webs are prevalent in cave systems, though you do have cases where again sunlight enters cavern openings or through other fissures, and also have situations where some manner of chemo autotrophy is taking place. But still you know, it often falls to bat guano as well as other transportation networks for dead plants and to tried us such as via gravitation, pawn or streams. It's like a steep sinkhole situation percating water. And also animal cadavers, the animal cadaver being something that is you know, the animal has gone in there and died or something has brought the animal couldaver into the cave generally.

So that's a good list. So as you said, there are places where the sunlight gets in. Chemo autotrophy would be an alternative to photo autotrophy. You know, mostly we're on the on the surface, the autotrophs are making energy out of sunlight, but it can also be done with certain types of chemicals in the darkness. And then as you said, bat iguano, and then just basically various ways for stuff to fall into the cave or be brought into the cave that could.

Be eaten, yeah, falling in and potentially flowing in in the same way that a dead olme might flow out of a cave, if we're to take that earlier accounted face value. So anyway, that's the base, you know, and you have all of these consumer interactions atop of all that in a cave. And this particular study examined the subterranean ecosystem of the Autovaska Cave and Slovakia. The predators they examined were all arthropods living in the cave, including a species of might a beetle, two different spiders, and a couple of other species, and they were able to examine DNA in the guts of each species to see what they were eating. As expected, they found a complex system of intragil prediction, again killing and eating of potential competitors, and they included a handy visual guy that I really liked, so I included it here for you to look at, Joe. They have essentially five dots scored here on the illustration, each one representing one of these five species they looked at, and then each one is color coded with color coded lines indicating which one feeds on which, and you end up with this complex almost pretty much a star pattern, but with a few more lines on some connections, and sometimes there's not a line connecting ones species to another.

It looks like almost all of them are eating each other. There's one that's really eating everybody and almost and all the others are eating at least two other ones.

Right right. And then you know they acknowledge their limitations and their study and so forth, so it's not this is not necessarily all that ever happens between these these species, but this is what they're they're got syndicated when they were studied, and so they stress that integill predation is often important in nitrogen poor diets, as is cannibalism, which that which they found evidence of, and it should be stressed that scavenging may be part of both cases. So you know, on one hand, you have like straight up predation like well there's my competitor, I've got the drop on them. I shall eat them, but also a situation of well there is my competitor, they have died.

What you're going to do right, Yeah, because often in energy relationships like this, trying to prey on a healthy adult of like a of a competitor within the food chain is usually going to be kind of dangerous. So I think we've read about integuild predation before, some of it being not predation but scavenging, but other ones being like adults of one species preying on the young of the other.

Yeah, because you know, otherwise, going toe to toe with someone or something in the ecosystem that is your equal, like, that's that's a gamble and survival is on the line regardless if you engage in that struggle, And you might only engage in that struggle if survival is already on the line. And yeah, it would seem in the impoverished food web of the dark, you get what you get. You don't pitch a fit. Each of the species here that they looked at consumed a wide variety of prey and indulged in integral predations as presumably necessary. So it would seem based on what reading here that Yeah, while you know, integral predation of course, as you said, occurs in the sunlit world as well and in the oceans and so forth, within the cave environment, it might be more pronounced again due to the limited scope of the available biomass, available nutrients and so forth.

Right, Yeah, I mean the fact that it's a place where food is scarce creates weird biological incentives and emphasies.

Yeah. So so, yeah, I thought this was very interesting. But I want to get into this other area here for the remainder of the episode here, having to do with outsiders in the cave, creatures who have come into the cave to take advantage of what is there. Because once again there's the there, there's the idea that the cave environment comes with pros and cons. One cons, as we've discussed already, is that the food chain here is just less robust, specialized obligate cave organisms generally have carved out a very narrow niche in which to live. A big pro, however, is, as with the OLM, you're often dealing with fewer predators and a more secluded life mm hmm. It's like the Phantom of the Opera. You know, you have this vast catacomb empire over which to rule and row your boat around, and you have great acoustics, you know, for your singing, for your your your cool pipe organ. But the real music scene is upstairs in the sunlit world, and you are, you know, to a large extent cut off from that.

You really need to kidnap a singer from up there to make your songs work better down there.

Yeah, yeah, so there there is a potential advantage here for creatures of both worlds and creatures of the surface that have figured out how and when to venture indicates to take advantage of the creatures that live there, at least live there periodically. And you know, I don't think we've run across anything that's going in to harvest the olms. But as we've been discussing, one of the most abundant life forms you might pray or scavenge upon the in caverns are creatures that spend part of their time there as well. That being bats, they roost in great numbers. They enjoy a great deal of security there. But a specialist could get in there and reap the bounties.

Oh, I don't know if I ever thought about that, So what would do that?

Well, a number of organisms. Actually, I was looking at a paper from nineteen seventy two. This is by Winkler and Atoms titled Utilization of Southwestern Bat Caves by Terrestrial Carnivores, and this is published in the Journal of the American Middland Naturalist. And they point out that various predators venture into caves to enjoy the occasional bat feast, either via active hunting or by scavenging for fallen bats. And this includes broadly like various reptiles, raptorial birds, and mammals. For instance, they point out that at Braw Cave, raccoons and some skunks were observed to venture into the cave to prey on fallen bats at the cave mouth. Because you know, I think we discussed this at least in Passing earlier. You have large populations of bats residing in many of these caves, and occasionally bats do fall be they you know, young bats, older bats, in firm bats, et cetera. They're just too many of them this for this not to happen. It will occasionally rain a little bit of food in the form of a bat and an organism that is operate into tunistic enough can get in there and collect those and eat them, or you know, eat them before they're able to crawl across the cave floor and then back up the walls to enjoy their roost again.

So the cave buffet underneath the bat roost is mostly guano, but occasionally bat meat as well.

That's right. So ringtail cats were observed at another cave, but it's aimed as if, especially at Brackencave, raccoons were the most likely to take advantage of the bat bounty during both the day and the night. And and you know this, this makes sense concerning the raccoon because as we've talked about in the show before, you know, they're they're great opportunists. Uh they are. They're nocturnal omnivores and they have exceedingly wise pause.

Oh that's right. I'm just now recalling that we did an episode a while back about their apparent their strange apparent washing of food behavior and the question about like whether that really is washing or some other type of behavioral instinct. And oh, I can't remember off the top of my head what episode that was in But I remember that that that one really got my mind.

Going, Yeah, I remember talking about like, for instance, they are they're they're great opportunistic organisms that can adapt to various environments, so they've done quite well with urban environments. Uh and uh and yeah. We also discussed the heartbreaking video foot that you can look up online of a raccoon attempting to to dunk. It's uh it's a plunder of cotton candy into the water and then seemingly confused as it draws the bounty back out of the water and finds that it is no longer uh there for it. It's again kind of heartbreaking to watch.

Yeah, totally, I just looked it up. By the way, it was in our series on animals, quote cooking things on the cuisine and kitchen behavior is observed in animals, including the apparent washing of food. But again, I think there was a question of whether that's really what raccoons are doing or not.

Yeah, but they're they're they're they're little paws, they are little hands. If you will are are are excellent. I've I've seen it described that they can essentially see you with their hands in ways that we could maybe relate to on some level, but as is often the case with the sense worlds of animals, of non human animals, we generally can't fully image what it's like like they they can see with their hands is the best way that we can perhaps understand it.

Yeah, yeah, that was one of the hypotheses. It was like that the water somehow hypercharges the sensitivity of the hands and sensing the food. Yeah.

Yeah. Now this cave in question, Bracken Cave, This is a Texas cave outside of San Antonio that is home to the largest known bat colony in the world. Some twenty million Mexican freetail bats roost here between March and October. This also apparently makes it the largest known concentration of mammals period, including humans. I'm assuming, and I imagine this takes into account the size of the cave and the estimates and estimated concentration of bats as compared to human cities. But even among human cities, they're only something like six cities with populations of more than twenty million, So we're talking a lot of bats. And I didn't run, I didn't look up or do the math on this, but you know, you think about twenty million bats, how many bats are going to potentially fall So that does create a certain opportunity for animals that are willing to get in there day or night and pick them off before they can get back up to the top.

Yeah, with twenty million bats, I mean, even if you assume a low death rate, that's got to be thousands falling into the floor all the time.

Yeah. Now, reptiles also get on the action as well, as that paper indicated, And one of the more alarming examples, I don't know, it could be alarming, depends on what you think about snakes is the example of yellow red rat snakes found in a cave in Mexico that is sometimes referred to as the Cave of Hanging Snakes.

Hanging snakes.

Yes, so the yellow red rat snake is endemic to Mexico and Central America, so it's fairly widespread. It's non venomous. It prays mostly on rodents and birds and lizards, but also on the menu are bats. So the Mexican cave in question is Cantemo Cave in the Mexican state of kintani Roo, about one hundred and eighty miles from Cancun, known locally, just as the bat cave. According to Jose Maria Morells, writing for Atlas Obscura, the snakes here have developed an amazing method of eating those bats that doesn't involve picking them off on the cave floor. So what they do, apparently, is they crawl up into the cracks in the ceiling of the cave as well as high up on the cave walls. And then when the bats, you know, the bats are roosting in there, so they leave and then they come back. They leave to feed, and then they come back. And when they're doing this, when they're going in or out of the cave, that is when the snakes will either dangle down or otherwise like lash out to catch a passing bat in its mouth. Wow. And I've included a couple of photos here for you to look at, Joe, one of the snake grabbing having grabbed a bat and it's like, you know, just swallowing it. And then there's another one of the snake up in the recesses. This is these are actually, these are excellent photos. They're from a Newsweek article that put that that profiled these snakes.

That is crazy. Now, I had a question that I think I may have partially answered, but I just looked up more images of these snakes jumping out to snag bats, and my question was, well, how do they have the leverage to do that? Because I was imagining them just sort of like crawling up a cave wall. But in some of the pictures I'm looking at, they have found like a they're in like a recess, like a cubby hole in the wall, and so I think they're gripping something back there with the back half of their body where they while they lunge out with the front half to to grab a bat.

Now you mentioned looking up images of this, Yeah, there there are a lot of images of these of these snakes. There's some footage as well. This cave has become an ecotourism destination, so a lot of people have gotten to go there. It's been covered in by a lot of news outlets, various documentaries. So you can definitely see some images of these snakes either you know, dangling from the ceiling or consuming the bats that they have acquired.

Wow, that's one of those behaviors where it's like I would love an evolutionary account of how that arises, if that's known or if there's something suspected, like how long have these snakes specialized in attacking bats this way? And like what were they doing before that?

Yeah? Yeah, I mean I guess it's kind of a natural extrapolation of surface world environments, especially I'm thinking our boreal environments. Right. The cave is just like a novel form of that. And with the bat population, you have just such a concentration of potential prey. You're going to have organisms that are drawn to it and ones that are able to adapt their existing practices. They're existing predation and scavenging practices to it, or as with the raccoon, are just generally great opportunists. You know, they're going to be able to help reap some of that bounty for themselves.

Well, Rob, thank you for introducing me to these hanging snakes. I didn't know they existed, and now I love them. So I think we probably have to call it there for part three of our series on cave biology, but I think we're going to be back for one more. Three was not enough. There will be one more episode.

I think, So I think a fourth episode will wrap it up for this journey into the caves, But you know, after that we'll probably be back in the future at some point or another. Caves and their ecosystems and human traditions associated with them are just too fascinating, all right. In the meantime, we're going to go ahead and remind everybody that's stuff to blow your mind. Is primarily a science and culture podcast that publishes new core episodes on Tuesdays and Thursdays, sandwiched in between there on Wednesdays there's a short form episode for you Monster Fact Artifact or Animalia stipendium. On Mondays we do listener mail, and then on Fridays we set aside most serious concerns to just talk about a weird film on Weird House Cinema. Usually those are self contained single episodes, but if you're just tuning into our channel for the first time, this week, we are covering David Lynch's nineteen eighty four adaptation of Dune in two parts, because it is that weird that packed with talent, and also, you know, Dune is in the air right now, the spice is in the air, and we have to acknowledge that.

Cool wahad huge thanks as always to our excellent audio producer JJ Posway. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hello. You can email us at contact at stuff to Blow your Mind dot com.

Stuff to Blow Your Mind is production of iHeartRadio. For more podcasts from my heart Radio's the iHeartRadio app, Apple Podcasts, or wherever you're listening to your favorite shows.

Stuff To Blow Your Mind

Deep in the back of your mind, you’ve always had the feeling that there’s something strange about re 
Social links
Follow podcast
Recent clips
Browse 2,740 clip(s)