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Hey, 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 2 today, but Joe is out sick, so we're going to 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 3-12-2024. Let's dive right in. Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. ♪
Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lamb. And I am 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 this 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 cave fish, about which there has been a lot of research, research on how exactly these fish evolved. These various populations of fish in northeastern Mexican caves evolved to lose their sight and lose the pigment in their flesh and so forth. Why that evolutionary pathway takes place in the cave environment and so forth.
Yeah, 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 Olm, also known as the Proteus. Scientific name, Proteus, I think you would say Onguinus. Proteus A-N-G-U-I-N-U-S.
The Ulm occupies underground waterways in Europe, especially karst caves of the Dinaric 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 Karst Studies from 2021 by Ivo Lucic called An Underworld Tailored to Tourists, a Dragon, a Photo Model, and a Bioindicator.
And Luczik 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 17th century author and natural historian named Johann Weikart von Valvasor, V-A-L-V-A-S-O-R, Valvasor, who wrote a book called The Ulm.
who was from the region then known as Carniola, what is today Slovenia.
And Valvasaur 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, the karst, the caves, the work did contain some investigations of the local karst, its caves, its associated culture and life. So here, summarizing Valvasaur, Lucic says that
Around 1689, Valvasaur reported that he had heard stories from peasants in a region known as the Vranica that they had seen a baby dragon in the local water source known as the Bela 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 9 a.m. 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 Valvasaur 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, a little bit just, you know, it depends what the lighting's like. But yeah, it's this long, slender organism with this elongated head and these wonderfully dainty little limbs.
Yeah, so it is a salamander in form. It has a kind of flat, almost elongated, I was going to 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 the snake like 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 that like 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 pretty readily accessible. 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 appearance. This is a being from another world, and its body and form is entirely alien to us.
It's funny. The rest of this paper by Luchik really emphasizes the extent to which 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 a tourist attraction. And 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 Valvasaur, a scientific view of this creature changed.
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. Hmm.
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 2020 by Balazs, Leworn, and Hertscheg called Extreme Site Fidelity of the Olm, 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 characteristics 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 variant cousins. 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 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, the
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.
And, 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 humans.
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 troglobionts, the fully adapted to cave species,
There are not a whole lot of those, but one of the best known exceptions is the Ulm. 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 Bulog in 1994 and Tronte in 2007 to suggest that the ancestors of the Ulm probably colonized caves somewhere between 8.8 and 20 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 Olm I remember running across. And it stuck with me because that sounds like such a like a death metal olm.
Yeah. In your European caverns. But apparently just the difference is for some reason, this is the one population that has retained its pigment within the caves. 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, um,
How scary do you have to be in order to be the top predator in a cave ecosystem where, again, you do have a food chain, you do have a certain amount of biomass available, but 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. Yeah.
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. They're the top of the pyramid. Because they have no predators, there's a part later in this paper where the authors observed that the Ulm do not seem to engage in hiding behaviors, that they observed at least. They said it's possible that
Some ohms hide back in cracks and crevices that they were never able to access on their dive, so 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. They're just not worried about something. 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 eating a lot, eating everything around them. No, actually, the olm is famous for having an incredibly...
incredibly elastic energy needs like it it can survive 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 in a given environment, you need to be able to really stretch out those spaces between mealtimes. It's noted that they're neotenic, meaning they retain juvenile features into adulthood. And there are 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 reotaxis. Reotaxis is the ability to sense the direction of flow within the water and
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. Yeah.
They also use other senses than sight. They have underwater hearing. They use their sense of smell or olfaction. And they appear to have a magnetic sensory ability as well, which may help them orient with respect to Earth's magnetic field, possibly useful for orientation and navigation.
As I said, the olm has very restricted food needs like some other troglobionts 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 a
extreme life history adaptations meaning uh the the their life just appears to sort of sort of go in slow motion compared to salamanders you might find on the surface so i was looking up the maximum lifespan of surface amphibians and of course that varies but you know on average it's going to be more in the range of 10 to 20 years for large amphibians that live live on the on the surface
The Ulm is thought to live for 100 years or more. Wow. With females only reproducing once every 12 and a half years, roughly. So that is an incredibly long life for an amphibian, incredibly long in between mating and reproduction. So this experiment tried to study the behavior of the Ulm, especially the movement and migratory patterns of the Ulm.
by using a capture, mark, and recapture method. So, you know, they'd catch one, they'd mark it, 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 extreme sight fidelity. Most of the creatures that they captured 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 gaps in the movement patterns that would indicate environmental features they were trying to avoid. And so they say their best guess is...
is that this hyper-sedentary lifestyle is probably related to energy constraints. The authors write, 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 12.5 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 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 authors also know, 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. Hmm. Yeah. I mean, I,
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 the movements of the waters that have at least historically been attributed to ones occasionally washing out and so forth. Mm hmm.
And if even even if one didn't wash out all the way to where humans could observe them, it might wash them out to where other organisms would have a shot at scavenging them. But still, it's an interesting tidbit. Yeah. Yeah. Yeah. To be clear, I don't think they meant like humans.
humans have never observed a dead one, obviously. I think they mean like 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 authors add a conservation note in their paper, which is that the extreme site fidelity of the, of the OM makes it quite
quite vulnerable to water pollution, you know, 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 Ulm, you should look this one up. You want to see this flesh? Oh, yeah, absolutely. It's a very Cronenberg biodesign. Yeah.
Yeah, they're, like I say, they're a little creepy, a little cute. They're very unique. ♪
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All right. I want to get into a topic here that came up early on in my research, a paper that came up pretty early on in researching these episodes. And it has to do with intra-gill 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 subterranean ecosystem 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
And as discussed in a 2021 paper published in Scientific Reports by Pera Muchova et al., quote, the food web in a subterranean ecosystem is driven by intrageld 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 you 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 in detritus, such as via gravitation, ponor streams. It's like a steep sinkhole situation, percolating 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 cadaver into the cave.
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 photoautotrophy. Mostly 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 guano 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 ohm might flow out of a cave if we're to take that earlier account at 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 Orovaska cave in Slovakia. The predators they examined were all arthropods living in the cave, including a species of mite, a beetle, two different spiders, and a couple of other species of insecticides.
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 predation. Again, killing and eating of potential competitors. And they included a handy visual guide that I really liked, so I included it here for you to look at, Joe. They have essentially...
five dots, um, uh, 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, uh, complex, almost pretty much a star pattern, but with, uh,
a few more lines on some connections, and sometimes there's not a line connecting one species to another. It looks like almost all of them are eating each other. There's one that's really eating everybody.
And all the others are eating at least two other ones. Right, right. And then, you know, they acknowledge their limitations in their study and so forth. So this is not necessarily all that ever happens between these species, but this is what their guts indicated when they were studied.
And so they stress that intragil predation is often important in nitrogen-poor diets, as is cannibalism, 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. Right.
what you're going to do. Right. Yeah. Because, uh, often in, uh, 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, uh,
interguild 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 otherwise going toe to toe with someone or something in the ecosystem that is your equal is
Like 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 predation as presumably necessary.
So it would seem, based on what I was reading here, that, yeah, while 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. I mean, the fact that it's a place where food is scarce creates weird biological incentives and emphases. Yeah. Yeah.
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 idea that the cave environment comes with pros and cons.
One con, 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.
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 make your songs work better down there. Yeah. Yeah.
So 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 into caves 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 alms. But as we've been discussing, one of the most abundant life forms you might pray or scavenge upon in cabins is
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 1972. This is by Winkler and Adams, titled Utilization of Southwestern Bat Caves by Terrestrial Carnivores. And this was published in the Journal of the American Midland Naturalist. And they point out that various predators venture into caves to enjoy the occasional bat feast, either via active hunting or
or by scavenging for fallen bats. And this includes broadly like various reptiles, reptorial birds, and mammals. For instance, they point out that at Bracken 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, infirm bats, etc. There are just too many of them 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 opportunistic 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 seemed as if, especially at Bracken Cave, raccoons were the most likely to take advantage of the bat bounty during both the day and the night. And, you know, this makes sense concerning the raccoon, because as we've talked about on the show before, you know, they're great opportunists.
Uh, they are, they're nocturnal, uh, omnivores and they have exceedingly wise paws. Oh, that's right. I'm just now recalling, uh,
We did an episode a while back about their strange apparent washing of food behavior and the question about whether that really is washing or some other type of behavioral instinct. Oh, I can't remember off the top of my head what episode that was in, but I remember that one really got my mind going. Yeah, I remember talking about, for instance, they're great opportunistic organisms that can adapt to various environments. So they've done quite well with urban environments.
And yeah, we also discussed the heartbreaking video footage that you can look up online of a raccoon attempting to dunk its plunder of cotton candy into the water and then seemingly confused as it
the bounty back out of the water and finds that it is no longer 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 behaviors 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 their little paws, their little hands, if you will, are excellent. I've seen it described that they can essentially see 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 imagine 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, uh, that, that was one of the hypotheses 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 20 million Mexican free-tailed bats roost here between March and October. This also apparently makes it the largest known concentration of mammals, period, ever.
including humans, I'm assuming. And I imagine this takes into account the size of the cave and the estimated concentration of bats as compared to human cities. But even among human cities, there are only something like six cities with populations of more than 20 million. So we're talking a lot of bats. And I didn't look up or do the math on this, but you think about 20 million bats, how many bats are going to potentially fall from
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 20 million bats, I mean, even if you assume a low death rate, that's got to be, that's 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
This 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 there.
It's non-venomous. It preys mostly on rodents and birds and lizards, but also on the menu are bats. So the Mexican cave in question is Cantimo Cave in the Mexican state of Quintana Roo, about 180 miles from Cancun, known locally just as the Bat Cave, according to Jose Maria Morelos 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 were 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, swallowing it. And then there's another one of the snake up in the recesses. These are excellent photos. They're from a Newsweek article 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.
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
But in some of the pictures I'm looking at, they have found like a they're in like a recess, like a cubbyhole 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 grab a bat. Now, you mentioned looking up images of this. Yeah, 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 a lot of news outlets.
various documentaries. So you can definitely see some images of these snakes either 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
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 arboreal 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, their existing predation and scavenging practices to it. Or as with the raccoon are just generally great opportunists
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 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 forum episode for you, Monster Fact, Artifact, or Animalia Stupendium, on
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 1984 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. Yeah.
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