Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2: Hey are you welcome to Stuff to Blow your Mind?
Speaker 2: My name is Robert.
Speaker 3: Lamb and I'm Joe McCormick, and we're back with part
Speaker 3: two of our series on mud. Now. In the last episode,
Speaker 3: we talked about some sort of definitional constraints on the
Speaker 3: idea of mud, and yes, it is the mud you're
Speaker 3: thinking of, as in wet soil, typically composed of small
Speaker 3: particles of the silt or clay particle size variety, But
Speaker 3: we also talked about mud in the sort of geohistory
Speaker 3: of Earth, in the history of how the continents were
Speaker 3: colonized by early plants and animals terrestrial life, and how
Speaker 3: the presence of mud was sort of was sort of
Speaker 3: driven by the presence of plants on Earth's continents, and
Speaker 3: then how the build up of mud on the continents
Speaker 3: from there sort of shaped the way the continents developed.
Speaker 3: But before that, we also talked about a passage in
Speaker 3: The Fairy Queen, which is a late sixteenth century English
Speaker 3: epic poem by the poet Edmund Spencer in which the
Speaker 3: author talks about his belief that the mud of the
Speaker 3: Nile and maybe just mud in general spawns monsters, and
Speaker 3: I knew we were not done with the idea of
Speaker 3: monsters that grow out of mud. Surely there's going to
Speaker 3: be a lot of that going around. And Rob, I
Speaker 3: think you had one as well, didn't you.
Speaker 2: Yeah. I actually looked into this a little bit last
Speaker 2: year because I worked a mud monster into the script
Speaker 2: I wrote for Thirteen Days of Halloween last year, and
Speaker 2: I was looking for inspiration regarding mud monsters, and at
Speaker 2: least at the time, I didn't find as many as
Speaker 2: I thought I would, But I did find one really
Speaker 2: interesting one. This one is a yokai from Japanese traditions,
Speaker 2: and it's non is the doughra Tabo. This name means
Speaker 2: either mud man or rice paddy man, and this yokai
Speaker 2: is generally described and depicted as a humanoid made out
Speaker 2: of mud, or at least a torso of a humanoid
Speaker 2: made out of mud, emerging from the mud of a
Speaker 2: rice patty, grasping with its arms and staring out through
Speaker 2: a single eye in its head as it wails at
Speaker 2: the night.
Speaker 3: It's brutal looking. It's got a kind of mud skeleton
Speaker 3: like you can see the ribs at least.
Speaker 2: Yeah, it's a frightening looking yokai, that's for sure. Of course,
Speaker 2: frightening in yokai doesn't necessarily mean it's going to try
Speaker 2: to kill you. And well that's how it basically breaks
Speaker 2: down in this one. I have a really fun yochai
Speaker 2: book that my son and I read last year. This
Speaker 2: is from Heroko Yoda and Matt Alt titled Yokai Attack.
Speaker 2: It's a fun little book. They has some great illustrations,
Speaker 2: and they point out that the doughro Tabo is not
Speaker 2: generally believed to be dangerous. It cries and frightens those
Speaker 2: who encounter it, but that's about it. Some traditions say
Speaker 2: that it originated as a man who lost his hard
Speaker 2: won farmland and now haunting the rice fields, cries for
Speaker 2: its return in the.
Speaker 3: Night, wait the return of the fields, like as the
Speaker 3: mud monster. He wants to now again be the rightful
Speaker 3: owner of the fields.
Speaker 2: Yeah, yeah, you know, it's like this was my place
Speaker 2: and now you've taken it from me, you know, basic
Speaker 2: haunting one oh one. Right. But the authors here also
Speaker 2: share that the Doro Tabo's origins go back at least
Speaker 2: as far as Sekan Toriyama's famous eighteenth century Yokai book
Speaker 2: Tales of Monsters Then and Now, And while it might
Speaker 2: be based on pre existing folk tales, they think it's
Speaker 2: more likely the creation of Toriyama himself. And yeah, it's
Speaker 2: one of these things where it's the frightenings barid. Here
Speaker 2: loses some of its appeal when it seems that it
Speaker 2: might have been a little more than the embodiment of
Speaker 2: a crude sexual metaphor to stick a pole in the
Speaker 2: rice patty. So maybe its origins are less spooky and
Speaker 2: more just kind of skeazy. But still, and the thing is,
Speaker 2: you can see that too if you look at some
Speaker 2: of these illustrations. I mean, it's the monster's appearance is
Speaker 2: vaguely phallic, and the authors point out that Saykan may
Speaker 2: have been referencing brothels that were located north of Edo
Speaker 2: Castle at the time. But whatever the road to get there,
Speaker 2: the result is a pretty cool looking mud monster.
Speaker 3: Now, while we're on the topic of the intersection between
Speaker 3: mud and monsters, there is a movie example that I
Speaker 3: know we have to talk about. It's one not of
Speaker 3: a monster made of mud, but of a hero who
Speaker 3: must defeat a monster by using mud and your horror
Speaker 3: movie geeks out there, I know you you already know
Speaker 3: the one we're thinking of. It occurs in the transition
Speaker 3: to the third act in the original Predator, the movie
Speaker 3: starring Arnold Schwarzenegger and basically every other guy with muscles
Speaker 3: that you could think of in nineteen eighty seven. So,
Speaker 3: I know a lot of you have probably seen this movie,
Speaker 3: but just in case you have, ut I'll explain the
Speaker 3: setup to the mud scene. So the premise of the
Speaker 3: movie is that Arnold Schwarzenegger is leading a group of
Speaker 3: private military contractors on a hit for the CIA in
Speaker 3: the jungle somewhere in Central America. Unbeknownst to them, they
Speaker 3: just happen to be jumping right into the hunting grounds
Speaker 3: of an alien from another planet who likes to come
Speaker 3: to war zones on Earth to hunt humans for sport.
Speaker 2: Yeah, he likes it hot, he likes it violent, and
Speaker 2: that's why he's heer.
Speaker 3: That's right. And I always took it to mean that
Speaker 3: the Predator seeks out war zones because it's like, you know,
Speaker 3: the humans aren't going to notice as much that people
Speaker 3: are going missing.
Speaker 2: Yeah, there's always a lot of there's already distress there's
Speaker 2: already people vanishing. It can get in and do its
Speaker 2: thing without having to worry about stirring up the locals
Speaker 2: too much.
Speaker 3: Oh but it's also because the predator wants to hunt
Speaker 3: like the toughest, like armed humans. Like he's specifically looking
Speaker 3: for humans of the Arnold Schwarzenegger with a machine gun variety. Yeah,
Speaker 3: so in this movie, the alien has all kinds of
Speaker 3: technology that gives the alien an advantage over humans. So,
Speaker 3: for example, it can put on a cloaking device that
Speaker 3: makes it nearly invisible to the naked eye. But it
Speaker 3: also has a huge advantage in that instead of just
Speaker 3: seeing the world in the visible spectrum of light like
Speaker 3: we do, it sees in infrared, so the body heat
Speaker 3: of a living organism really pops out of the background,
Speaker 3: making any warm blooded animal easy to track in the forest.
Speaker 3: So by the end of the second act of the movie,
Speaker 3: this alien has trophy hunted Arnold Schwarzenegger's entire team. Only
Speaker 3: Arnold is left, and just when you think he's done for,
Speaker 3: he ends up he's running away from the alien. He
Speaker 3: ends up crawling on his belly across a muddy river bank,
Speaker 3: so that his entire body ends up covered in mud.
Speaker 3: And I will note that the mud. I was just
Speaker 3: thinking back on the scene, it does appear to have
Speaker 3: a lot of clay sized particles. I think that's a
Speaker 3: clay rich mud.
Speaker 2: Yeah, it does look look very clay rich.
Speaker 3: But anyway, so yeah, Arnold Schwarzenegger ends up total. He's
Speaker 3: totally covered in mud. He's lying there on the river
Speaker 3: bank waiting for the predator to finish him off, and
Speaker 3: to his surprise, suddenly it seems like this alien hunter
Speaker 3: can't see him. The mud has made him invisible to
Speaker 3: the alien So finally he has an advantage to even
Speaker 3: the playing field against this enemy with overwhelming technology, and
Speaker 3: sort of that sets up the big conflict in the
Speaker 3: third act. It's a great twist. I remember when I
Speaker 3: first saw the movie as a kid, I thought it
Speaker 3: was genius.
Speaker 2: It's pretty great, and it's been very influential because you
Speaker 2: see this either directly referenced in so many films to
Speaker 2: come afterwards, or films will find sort of a new
Speaker 2: way to do the same thing, Like our hero accidentally
Speaker 2: finds some sort of protection from from some sort of
Speaker 2: an enemy, or you know, accidentally finds this key strategy
Speaker 2: that they can employ against said enemy.
Speaker 3: Now, while if I remember correctly, I think nobody in
Speaker 3: the movie actually explains how this works. You're just left
Speaker 3: to sort of figure it out for yourself. But the
Speaker 3: way it is presumed to work is that by covering
Speaker 3: his body in mud, Arnold Schwarzenegger here has masked his
Speaker 3: the heat signature of his body because it's now the
Speaker 3: mud is the same temperature as the rest of the environment,
Speaker 3: so he just blends in.
Speaker 2: Yeah, now, this is a scene that's a lot of
Speaker 2: fun to dissect, and maybe maybe almost too fun to dissect,
Speaker 2: Like you can get a little too wrapped up and
Speaker 2: trying to break down whether this will work or not,
Speaker 2: and you have to at the end of the day
Speaker 2: remind yourself, well, we need to experience it through the
Speaker 2: you know, the cinematic excitement of the scene. But still,
Speaker 2: there are a couple of key conversations about this. I
Speaker 2: found one that was really interesting that I had not
Speaker 2: run across before from a book titled The Sensory Modes
Speaker 2: of Animal Rhetorics by Alexy Parrish, and at one point
Speaker 2: in the book, Parish examines this scene, and it seems
Speaker 2: to have a mostly high opinion of the sequence He
Speaker 2: points out that quote, infrared radiation is nearly impossible to
Speaker 2: detect through any amount of water, so the wet mud
Speaker 2: masks Dutch's heat signature. Dutch is the character that Arnold
Speaker 2: plays from the Predator once his high tech mass becomes
Speaker 2: damaged in one of the earlier struggles. I think one
Speaker 2: of the it's been a while since I've seen Predator
Speaker 2: in its entirety, but I think part of it too,
Speaker 2: is that the Predator sees an infrared but it has
Speaker 2: kind of like a it sees everything in infrared, and
Speaker 2: it has some of these technological filters that can throw
Speaker 2: on to sort of refine that a bit.
Speaker 3: Yes, and it may it may have lost some of
Speaker 3: its capabilities in previous combat. Yeah, I'm not sure. Though.
Speaker 2: Now we'll come back to sort of the you know,
Speaker 2: the science of this. I should point out though, that
Speaker 2: I believe Parish's main interest in this is not really
Speaker 2: about like the direct infrared radiation and thermal science of
Speaker 2: the scenario, but he's he's more interested on this sort
Speaker 2: of this idea of this being an interaction between two
Speaker 2: beings with entirely different sensory understandings of the world, and
Speaker 2: he likes this example because quote Dutch is able to
Speaker 2: think outside his own lived experience and quickly adapt to
Speaker 2: an alien way of sensing the world. So humans can't
Speaker 2: detect infrared radiation without the aid of technology, and therefore
Speaker 2: most of us are just essentially blind to this realm
Speaker 2: of senses, the direct experience of it, certainly, but also
Speaker 2: perhaps just sort of the idea of it. And you know,
Speaker 2: you throw throw in a very stressful, life threatening situation
Speaker 2: like that depicted in the movie, and you know it
Speaker 2: adds his extra layer to it, So it's kind of
Speaker 2: neat like that. Ultimately, the quality that Dutch has that
Speaker 2: makes him an effective hero in the movie is not
Speaker 2: that he has big muscles or he can blow things up.
Speaker 2: He can do all of those things, unless those skills
Speaker 2: seem to serve him well against other humans. But at
Speaker 2: this point in the movie, it is essentially he's essentially
Speaker 2: about to be killed. His only his trick to surviving
Speaker 2: is being able to think outside of the human experience
Speaker 2: and realize why, I'm part of its luck too. Obviously
Speaker 2: that he just happened to get so muddy, happened to
Speaker 2: fall into that water. But then, you know, being swift
Speaker 2: enough to realize, Oh, this is what is happening, This
Speaker 2: is what has given me the edge.
Speaker 3: Yes, but I guess that brings us back to the
Speaker 3: question of would something like this work in real life, Like,
Speaker 3: I don't know, how would it change your infrared heat
Speaker 3: signature to cover your body in mud?
Speaker 2: Well, as I know a number of you out there
Speaker 2: are familiar with this already because we have I think
Speaker 2: there's a lot of crossover between our listeners and viewers
Speaker 2: of the TV show MythBusters. But yeah, there is an
Speaker 2: episode of MythBusters that busted this myth. They experimented with
Speaker 2: a thermographic camera and they found that it would work,
Speaker 2: but would only work for a very brief amount of
Speaker 2: time until the mud heated up from the human body
Speaker 2: temperature underneath it.
Speaker 3: Hmm.
Speaker 2: Okay, And I've seen some other analyzes that line up
Speaker 2: with this as well, arguing that okay, it could work,
Speaker 2: but probably not for as long as it seems to
Speaker 2: work in the movie. Also based on how relative little
Speaker 2: mud is involved. So I take that to mean if
Speaker 2: Arnold aka dots here had just been completely mud monstered himself,
Speaker 2: like he didn't even look like Arnold anymore, you could
Speaker 2: make a better case for it working, but then it
Speaker 2: would have looked a little silly like. Part of the
Speaker 2: peel of the scene too, is that you know, Arnold's
Speaker 2: face and muscles are covered with this clay like mud slime.
Speaker 3: You can still see the muscles clearly defined, but he
Speaker 3: looks like he's sort of covered in gray paint.
Speaker 2: Yeah, now, Joe, I think you've seen this as well.
Speaker 2: But the twenty twenty two film Prey cleverly adapts this,
Speaker 2: having our hero in this movie, instead of covering themselves
Speaker 2: with mud, they ingest a traditional medicine that it's described
Speaker 2: as it lowers one's body temperature through medicinal means and
Speaker 2: is able to then give the hero the same advantage
Speaker 2: over the predator.
Speaker 3: That was a good twist.
Speaker 2: Yeah, now, I guess you could argue that Dutch was
Speaker 2: also cooling his body temperature because you know, he first
Speaker 2: jumps off a waterfall, I think, into this water. Then
Speaker 2: he gets covered in the mud. But I can't imagine
Speaker 2: that this on its own would have been enough to
Speaker 2: make a difference, Like it wouldn't have really low. It's
Speaker 2: not like he was jumping into like freezing water down there. However,
Speaker 2: this is just occurring to me, Now, if we think
Speaker 2: of what we see in Predator as sort of the
Speaker 2: myth that spawned by some sort of an event that
Speaker 2: actually happened, I could imagine a situation where Okay, Dutch
Speaker 2: is running for his life, jumps into the cold water,
Speaker 2: crawls through the mud, is covered with the mud, but
Speaker 2: instead of then having a direct confrontation with the predator,
Speaker 2: already has some distance and the predator is not able
Speaker 2: to scan him from a distance in this short time
Speaker 2: it takes for him to then get the rest of
Speaker 2: the way out of range and find a place to hide.
Speaker 3: Yeah, or in the real world scenario just has a
Speaker 3: much thicker coating of mud, like they didn't have to
Speaker 3: be concerned in the real world about making sure you
Speaker 3: could still tell it was arnold.
Speaker 2: Right, Yeah, But then I guess you're do Like there
Speaker 2: are all sorts of complications that arise there too, like
Speaker 2: how much mud can you cake on your body without
Speaker 2: it slouching off? How can you move with all that
Speaker 2: mud on your body? So there are limitations there as well,
Speaker 2: I think if memory serves, and it could be wrong
Speaker 2: on this, I think in the MythBusters episode they found
Speaker 2: that there were ways to to sort of mask your
Speaker 2: your your heat signature, but you had to you know,
Speaker 2: use some sort of like a thermal suit to do that.
Speaker 3: Well, I was just thinking, if you if you make
Speaker 3: it so that you're not giving off a visible heat signature,
Speaker 3: wouldn't that just mean you're retaining the heat and therefore
Speaker 3: you would get really hot?
Speaker 2: Hmm. Well, you know, in this we're getting really into
Speaker 2: the more and more into the thermal regulation side of
Speaker 2: the whole scenario, which is fortunate because as we venture
Speaker 2: into the world of real life animals that often cake
Speaker 2: themselves in mud, wallow and mud and ultimately use mud
Speaker 2: for other things, you don't really find animals covering themselves
Speaker 2: in mud to mask their the their ir signature. But
Speaker 2: we're going to look at several examples here of animals
Speaker 2: using mud for various purposes in their lives, and I
Speaker 2: think we're going to begin with probably the most notable example,
Speaker 2: the most famous example of a mud loving animal.
Speaker 3: That's right, So, one family of animals whose relationship with
Speaker 3: mud is quite well known is the family Suidy, the
Speaker 3: family containing all the animals commonly known as hogs, pigs, porkers,
Speaker 3: and swine, most notably to humans, SEUs domesticus, the common
Speaker 3: domestic pig now pigs, along with plenty of other animals
Speaker 3: like elephants, rhinoceroses, some bovids, et cetera, wallow in mud,
Speaker 3: and wallowing is defined as coating the body surface with mud,
Speaker 3: often simply by lying in a pit of muddy water,
Speaker 3: or even sort of rolling around or wiggling in a
Speaker 3: pit of muddy water. But when I thought about it,
Speaker 3: I realized I didn't really know why pigs wallow. My
Speaker 3: best guess was that it had something to do with temperature,
Speaker 3: but I didn't know. So to answer this question, I
Speaker 3: dug up a paper, a paper in an animal behavior
Speaker 3: journal exploring exactly the question of why pigs wallow in mud.
Speaker 3: So the article was by Mark Braka called Review of
Speaker 3: Wallowing in Pigs, Description of the behavior and its motivational
Speaker 3: basis in the journal Applied Animal Behavior Science from the
Speaker 3: year twenty eleven. And there's some interesting motivating context for
Speaker 3: this paper, which is that it was really aimed at
Speaker 3: informing decisions about animal welfare in a domestic context or
Speaker 3: in agriculture, because, of course people keep pigs domestically as
Speaker 3: a farm species, and sometimes even as pets, so to
Speaker 3: treat them humanely means understanding what their needs are, and
Speaker 3: it has been widely observed that pigs wallow in mud
Speaker 3: when they can. So is this something that pigs need
Speaker 3: to do for their well being? And if so, why
Speaker 3: do they need to do it so? The paper consists
Speaker 3: of a literature review the existing evidence on why domestic
Speaker 3: pigs and related species such as wild boares coat their
Speaker 3: bodies in mud. I guess the first question is what
Speaker 3: does this actually look like? Well, like, when pigs and
Speaker 3: wild pigs and bores wallow, what do they do? Bracket
Speaker 3: writes that if a pre existing pool of mud is
Speaker 3: not available, pigs will often make their own. They will
Speaker 3: like dig to make their own wallow. And the pit
Speaker 3: of mud or muddy water where pigs wallow the verb
Speaker 3: is called a wallow the noun so it's kind of
Speaker 3: like how you shower in the shower. They wallow in
Speaker 3: the wallow. When a wallow is available, the pig will
Speaker 3: usually begin by rooting, which means repeatedly pushing the snout
Speaker 3: in and sort of rooting and digging in the mud,
Speaker 3: and then they will enter the mud with the four
Speaker 3: body first, headside first and then wiggle and roll around
Speaker 3: in the mud, sometimes until much of the body, or
Speaker 3: occasionally even the whole body is covered in mud. Now,
Speaker 3: how much of their body they submerge in the mud
Speaker 3: has been observed to correlate somewhat with temperature. According to
Speaker 3: mcgloon in nineteen ninety nine, when the temperature is above freezing,
Speaker 3: pigs will stand in the cool water. When the temperature
Speaker 3: goes up from there, more often they will lie down
Speaker 3: with their utters submerged in the water, And when it's
Speaker 3: even hotter, they will sometimes like roll around and coat
Speaker 3: most or or all even of the of the body
Speaker 3: in mud. But more often the parts of the body
Speaker 3: they get coated in mud are the sides and the underside.
Speaker 3: The author says, if the wallow is deep enough and
Speaker 3: the temperature is high enough, sometimes a sow will submerge
Speaker 3: its entire body, so only the head and the snout
Speaker 3: is poking out. But on hot days it's normal for
Speaker 3: a pig to keep fifty to seventy five percent of
Speaker 3: its body surface covered in mud. Now some observers do
Speaker 3: note that pigs will exhibit wallowing behavior even in cold weather.
Speaker 3: That'll come back in a bit, but they just they
Speaker 3: clearly do it more often in hot weather. Apparently becomes
Speaker 3: really prevalent around seventeen to twenty one degrees celsius, which
Speaker 3: is about sixty three to seventy degrees fahrenheit. So sometimes
Speaker 3: a pig will stand or lie down in the mud
Speaker 3: and just hang out there. Other times the pig will
Speaker 3: get in the mud, get a coat of the mud,
Speaker 3: and then leave and let it evaporate as the pig
Speaker 3: goes about its business, maybe returning later to get another coat.
Speaker 3: Pigs are often seen scratching off their coats of dried
Speaker 3: mud against a tree or other scratching post type object.
Speaker 3: So you might get in the mud, get mud all
Speaker 3: over your skin, let the mud dry, and then scratch
Speaker 3: against a tree to get the dried mud off. But
Speaker 3: what purpose biologically does mud wallowing serve? Well, one of
Speaker 3: the most obvious and widely recognized benefits is thermoregulation. As
Speaker 3: we were talking about, wallowing in mud clearly helps pigs
Speaker 3: keep cool. Pigs actually have comparatively little in terms of
Speaker 3: internal biological mechanisms for fighting off the heat, especially compared
Speaker 3: to some other species. They have fewer sweat glands than humans.
Speaker 3: For instance, and there was a paragraph in this paper
Speaker 3: that actually made me feel so much emotion about what
Speaker 3: it's like to be a pig, about how hot it
Speaker 3: must be to be a pig, especially a domestic pig.
Speaker 3: Do you mind if I read this, Rob, Yes, let's
Speaker 3: do so. Bracho writes, for several reasons, pigs are prone
Speaker 3: to overheating. Their sweat glands are hardly responsive to elevated temperatures,
Speaker 3: subcutaneous fat may result in a relatively high insulation value,
Speaker 3: and their barrel shaped body reduces body surface to body
Speaker 3: mass ratio and this reduces heat exchange. In addition, compared
Speaker 3: to wild boar, domesticated pigs have shorter snouts and this
Speaker 3: reduces their ability to pant. Furthermore, while domesticated pigs have
Speaker 3: sparse hair cover and larger ears, their ears are not
Speaker 3: very mobile and vascularized as in the case of elephants,
Speaker 3: and their circulatory system has a limited capacity. Finally, pigs
Speaker 3: may be producing considerable amounts of heat e g. Due
Speaker 3: to muscular activity and feeding, fighting and play, and very
Speaker 3: high production levels, growing up to about one kilogram per
Speaker 3: pig per day, producing up to thirty piglets per sow
Speaker 3: per year. So this just sounds like pigs are busy
Speaker 3: getting and stayin hot. It is hot to be a pig,
Speaker 3: you need to find ways to cool off. So because
Speaker 3: of the convergence of all these limitations and their vulnerability
Speaker 3: to heat, pigs have to supplement their basical sort of
Speaker 3: internal or anatomical cooling capabilities with behavioral ones. And this
Speaker 3: could in some cases be as simple as reducing your
Speaker 3: movement and seeking out shade when the sun is high,
Speaker 3: But it also includes wallowing. So strong is a pig's
Speaker 3: desire to wallow that in some cases, if water and
Speaker 3: mud are not available in the pig's environment, they will
Speaker 3: lie down against any wets they can find, or even
Speaker 3: lie against their own feces and urine. Pigs really want
Speaker 3: to get their skin wet. But it's interesting to consider
Speaker 3: the complexity of how the wallowing works, like it's more
Speaker 3: complex than simply the way we would jump in water, say,
Speaker 3: get in the pool to cool off. We all know
Speaker 3: that it is cooler to be in the pool than
Speaker 3: out of the pool, and studies show this is of
Speaker 3: course true with the puddles of mud and pig habitats,
Speaker 3: even if they're in direct sun. But this is not
Speaker 3: just about the time that the pig is physically in
Speaker 3: the mud in the wallow, because if you think of
Speaker 3: the pool analogy, when your skin is wet as you
Speaker 3: slowly dry off, it takes a lot of energy to
Speaker 3: turn the water clinging to your skin into water vapor,
Speaker 3: and that results in a heat transfer from your body
Speaker 3: to the water as it makes that costly phase transition
Speaker 3: into vapor. So you can think of why you feel
Speaker 3: cold after you get out of the shower, even if
Speaker 3: the shower water was hot.
Speaker 2: Yeah, this is a great point and with I found
Speaker 2: this with a child. This this period of transition between
Speaker 2: getting out of the swimming pool and going you know,
Speaker 2: back into the house or the room or whatever like
Speaker 2: this is pivotal. Smaller bodies thrown into the mix as well,
Speaker 2: because yeah, they're instantly colder when they get out of
Speaker 2: the pool, but they cannot go back in the pool,
Speaker 2: and you're gonna, i think, maybe have diminishing returns of
Speaker 2: trying to heap back up in the pool. And for
Speaker 2: you know, again a small bodied child, this is gonna
Speaker 2: be an even more dire situation. They need those towels,
Speaker 2: they need to get to a warm shower somewhere as
Speaker 2: they can warm back up right.
Speaker 3: And this is also actually the same principle by which
Speaker 3: sweat cools your body. Water evaporating from the skin makes
Speaker 3: your body cooler. It's a cooling technique. But another thing
Speaker 3: you might know from getting out of the pool is
Speaker 3: that water drips and evaporates off of the skin pretty quickly,
Speaker 3: So once you leave the pool or the shower, whatever
Speaker 3: it is, the cooling potent of evaporation is relatively short lived,
Speaker 3: probably on the order of just minutes under a hot sun.
Speaker 3: I'm reminded of a time I was hiking in a
Speaker 3: Big Bin National Park in Texas under you know, this
Speaker 3: is a desert environment where like the sun is beating
Speaker 3: down and I remember I was very hot. So I
Speaker 3: took like an icy water bottle that I had, and
Speaker 3: I poured the water just all over myself, like on
Speaker 3: my head and down my back. So my shirt was
Speaker 3: soaked in water, and I remember it. So I was like, okay,
Speaker 3: so I'll be good. You know, I'm like wet with
Speaker 3: this icy water, my clothes are wet. I should be
Speaker 3: good for a while. But I don't know how long
Speaker 3: it was, but it felt like within fifteen minutes, I
Speaker 3: was bone dry, So being wet and evaporating helps you
Speaker 3: cool off, but it doesn't last that long. Here's the
Speaker 3: genius of mud wallowing. These these studies unwallowing showed that
Speaker 3: an animal such as a wild pig, coated in mud
Speaker 3: stays wet much longer after getting out of the wallow
Speaker 3: than the same animal coated in water alone. Mud keeps
Speaker 3: you wet longer than water and the mud. Essentially, it
Speaker 3: seems like it helps create a matrix for trapping water
Speaker 3: against the skin, which will still provide the benefits of
Speaker 3: evaporative cooling as it dries. But the mud may take
Speaker 3: hours to fully dry into a crust, while water alone
Speaker 3: is gone in minutes. To read from the study here,
Speaker 3: quote wallowing in mud leaves a coat of mud on
Speaker 3: the pig's lateral and ventral surfaces and limbs. This superficial
Speaker 3: layer of caked mud assists in relieving hyperthermia through evaporation,
Speaker 3: acting as a kind of quote wet suit, helping to
Speaker 3: keep cool in a warm environment. Water in mud on
Speaker 3: the skin of a pig took two hours to evaporate
Speaker 3: compared to fifteen minutes when water alone was used, and
Speaker 3: the evaporation rate was seven hundred to eight hundred grams
Speaker 3: per hour per meter squared. Some mud is more effective
Speaker 3: than clean water in temperature control because mud allows the
Speaker 3: evaporation process to continue for a longer time, so for
Speaker 3: cooling the body in hot conditions, mud is an upgrade
Speaker 3: from clean water.
Speaker 2: All right, that makes sense. Yeah, it's the water just
Speaker 2: flows right off here. The water evaporates, but the mud,
Speaker 2: the mud sticks.
Speaker 3: So Thermoregulation seems to be the most widely accepted explanation
Speaker 3: for why pigs wallow, and the one with the most
Speaker 3: evidence behind it, But there are a ton of other
Speaker 3: possible or partial explanations that have been offered. And one
Speaker 3: reason for this is that there have been observations that
Speaker 3: while pigs wallow less in cold weather, they still wallow some.
Speaker 3: So if they're doing it even when it's like really
Speaker 3: cold outside, it probably we must serve some purpose in addition,
Speaker 3: you know, like some other purpose in addition to just
Speaker 3: avoiding overheating. So what are some of the other explanations
Speaker 3: that have been offered. Well, a number of them have
Speaker 3: to do with various types of grooming in skincare. So
Speaker 3: imagine this pig has ectoparasites, on its skin. It might
Speaker 3: have fleas or lice or ticks or something. The pig
Speaker 3: cannot reach back and pick all these parasites off. Pig is, unfortunately,
Speaker 3: by way of evolution, stuck in barrel mode. But the
Speaker 3: pig can wallow, and by getting in the mud and
Speaker 3: lying in it wiggling around, wiggling around, that may kill
Speaker 3: or dislodge some of those parasites. But then the benefits
Speaker 3: continue even after the pig gets up out of the
Speaker 3: mud and the mud dries into a crust. The pig
Speaker 3: can go scratch its body against posts like trees or
Speaker 3: the pin wall or whatever to remove the mud crust
Speaker 3: and probably remove trapped parasites along with it.
Speaker 2: Oh, I'd never thought about that.
Speaker 3: Yeah, So this has been documented as an anti parasite
Speaker 3: behavior in water buffaloes. It is assumed by many to
Speaker 3: serve the same function in pigs, but there's some countervailing
Speaker 3: evidence that like the author here sites a study from
Speaker 3: two thousand and five that looked for evidence that wallowing
Speaker 3: reduced parasite loads in wild boar and actually did not
Speaker 3: find any correlation. So the picture on that one seems mixed.
Speaker 3: But there's also it's also been proposed that maybe having
Speaker 3: a layer of mud helps protect pigs from biting insects
Speaker 3: like flies and mosquitoes. That would make sense, and furthermore,
Speaker 3: a layer of mud could also help provide protection against sunburn,
Speaker 3: to which domestic pigs are susceptible. Domestic pigs can get sunburned.
Speaker 3: Being relatively hairless and not having a lot of natural
Speaker 3: skin protection against against the sun, they are vulnerable to sunburn.
Speaker 3: Though I was thinking, it's interesting that usually the mud
Speaker 3: ends up on the sides and the underside of the pig,
Speaker 3: more so than on the back of the pig, which
Speaker 3: would be the part that's in the most direct sunlight.
Speaker 3: But I don't know few other possible ideas. Maybe there's
Speaker 3: some kind of health benefit not related to heat. Pigs
Speaker 3: have been observed to wallow more when they are suffering
Speaker 3: from disease, and it's also been hypothesized that pigs wallow
Speaker 3: in order to perhaps disinfect wounds, because mud in some
Speaker 3: cases can have bacteriocytal properties. But this is another hypothesis
Speaker 3: that was not There was found to be no correlation
Speaker 3: in that same two thousand and five study that found
Speaker 3: no correlation with parasites on wild boar. At least there
Speaker 3: are other ideas that maybe it has some relationship to
Speaker 3: sexual behavior, such as scent marking or advertising mate fitness,
Speaker 3: but this also seems uncertain. So I'd say there is
Speaker 3: definitely plays a role in thermoregulation, and the fact that
Speaker 3: pigs also do it when it's very cold makes it
Speaker 3: seem like maybe it may have some other functions as well,
Speaker 3: but we're less certain about what those are.
Speaker 2: This is all fascinating. Yeah, with pigs and mud, I
Speaker 2: just always I kind of just had the loose understanding
Speaker 2: while they're doing it to cool down. But yeah, it
Speaker 2: sounds like it's sounds like there are more dimensions to that,
Speaker 2: And ultimately these additional dimensions cast light on many of
Speaker 2: the various other examples of wallowing and mud behavior that
Speaker 2: you see in animals. You know, and we're certainly not
Speaker 2: going to get into all of these examples today, but
Speaker 2: you can see how a number of these explanations can
Speaker 2: and do line up with these other species.
Speaker 3: Right, So you might you know, elephants, rhinoceroses, hippos, water buffalo,
Speaker 3: other bovids all engage in wallowing behaviors, and to some
Speaker 3: extent they probably share some of the same biological purposes.
Speaker 3: In fact, there was an interesting passage I did want
Speaker 3: to read from this paper about the evolution of wallowing.
Speaker 3: So the author writes, quote wallowing, defined widely as covering
Speaker 3: the body surface with a mud like substance, is common
Speaker 3: in mammals such as cervids, carnivores and primates. Pigs, however,
Speaker 3: prefer to wallow more specifically in mud, mainly for thermoregulatory
Speaker 3: reasons for cooling, and in this respect it resembles mud
Speaker 3: wallowing seen and other large animals giant tortoises, crocodiles, elephant, seals,
Speaker 3: and in particular in the large hairless mega herbivores such
Speaker 3: as elephants, rhinos, bison, and water buffalo. Pigs probably also
Speaker 3: descended from a large ancestor, by contrast to, for example,
Speaker 3: the horse, an odd toed ungulate, whose ancestor, the Eohippus,
Speaker 3: was far smaller than his descendant. So if I get
Speaker 3: what the author is going for here, it's sounds like
Speaker 3: he's suggesting that it's interesting that these species that engage
Speaker 3: in wallowing today tended to be things that had large
Speaker 3: bodied ancestors. Obviously, having a large body means that your
Speaker 3: cooling needs are more acute. And you know, a horse,
Speaker 3: on the other hand, evolves from something with a small
Speaker 3: body that has less acute cooling needs.
Speaker 2: That's fascinating. And yeah, the Galapagos tortoise in particular, they
Speaker 2: mentioned the giant tortoises. Yeah, this is a great example.
Speaker 2: I got to I mean, my family and I got
Speaker 2: to go out and see some of these animals in
Speaker 2: the wild. And there was one particular morning where, yeah,
Speaker 2: a lot of the tortoises had not yet emerged from
Speaker 2: their nightly mud. Some were just coming out, but some
Speaker 2: were still just you know, firmly parked in alone in
Speaker 2: this kind of wallow of mud. And it was going
Speaker 2: to be maybe a little bit the morning was gonna
Speaker 2: have to warm up a bit before they started coming
Speaker 2: back out again.
Speaker 3: But of course, the animal uses of mud are by
Speaker 3: no means limited to wallowing and thermoregulation. I mean, in
Speaker 3: a way you can almost think mud is not quite
Speaker 3: like water, but it is close to like water in
Speaker 3: that it is a material and a habitat.
Speaker 2: That's right. And there are various other things that animals
Speaker 2: do with mud that are worth mentioning. Here. One neat
Speaker 2: place to start is geofogy. This is something that's been
Speaker 2: known of an animals since at least the time of Galen,
Speaker 2: and it's been known that, you know, many animals on
Speaker 2: occasion will eat soil or clay or something that might
Speaker 2: be considered mud. This is one of the issues in
Speaker 2: talking about how animals use mud, as we fall back
Speaker 2: into the issue of definitions that we discussed in the
Speaker 2: first episode. What's mud, what's not mud? What is more?
Speaker 2: What would you more consider silt and sand and so forth?
Speaker 2: When does mud become dirt? So all of those questions
Speaker 2: and uncertainties remain in effect, but at least in some
Speaker 2: of these cases, animals would be eating something that you
Speaker 2: might define as mud. There are three main reasons for
Speaker 2: them to do this that are recognized. One is to
Speaker 2: control parasites I believe indo parasites in this regard. Another
Speaker 2: is for mineral contents such as iron, sodium, and magnesium
Speaker 2: something in the mud that they need for their diet.
Speaker 2: Another factor is to help metabolize toxic compounds. You know,
Speaker 2: they are various examples of this in the animal Kingdom,
Speaker 2: where at least during part of a season an animal
Speaker 2: bite might be forced to eat some plants that are
Speaker 2: a little rougher on the gut, and the added mud
Speaker 2: or dirt into the system will help sort of balance
Speaker 2: all of that out. Geophagy also factors into some human
Speaker 2: traditions as well, sometimes as a medicinal practice or other
Speaker 2: times as part of a survival dietary substitution practice. Though
Speaker 2: again we're focusing on mud here, and this ultimately goes
Speaker 2: beyond just mud, So it's a stretch, I think, to
Speaker 2: spend too much time on it, but mud is certainly
Speaker 2: on the table in the animal Kingdom. Now. Another big one,
Speaker 2: of course, is building with mud. Humans, we should note,
Speaker 2: are famous for building with earth and mud is a
Speaker 2: big part of that. And we're going to discuss more
Speaker 2: about humans specifically in the next episode. But of course
Speaker 2: we're not the only animals to make our homes out
Speaker 2: of mud. There are a few key examples to discuss here.
Speaker 2: I think one of the most impressive, though, and one
Speaker 2: that I think a lot of people, if not everyone,
Speaker 2: out there, will have some experience with, is that of
Speaker 2: the mud dauber or the dirt dauber or the mud wasp.
Speaker 3: As a child, I remember really wondering what.
Speaker 2: The word Dauber meant, yeah, yeah, I grew up hearing
Speaker 2: of them as dirt daubers, which is kind of a
Speaker 2: silly name. And also since it's like it's mud, that's
Speaker 2: I mean, ultimately it's mud. But then the mud dries.
Speaker 2: That's another one of the definitional problems here is the
Speaker 2: mud mud only remains mud for a little bit and
Speaker 2: then it becomes like dried mud or dirt and so forth.
Speaker 2: But anyway, yeah, the mud wasp. I'll call the mud
Speaker 2: the mud wasp moving forward because it sounds a little
Speaker 2: more serious. These are various species of I believe, two
Speaker 2: different families of parasitoid wasps. I definitely encounter these a
Speaker 2: lot during my own childhood. The resulting nests kind of
Speaker 2: look like, imagine a like a pan flute composed of
Speaker 2: cylinders that instead of being made out of you know,
Speaker 2: some sort of you know, like metal tubing or bone
Speaker 2: tubing or wooden tubing or what have you. Instead, those
Speaker 2: are made out of cylinders of dried mud. And if,
Speaker 2: when say, cleaning out an old shed or something, you
Speaker 2: happen to break some of these cylinders open, well, there's
Speaker 2: an additional level of surprise you might find that they
Speaker 2: are full of the remains of tiny spiders, because while
Speaker 2: the adults are typically nectar drinkers, the young require the
Speaker 2: meat and the bodies of host organisms in the form
Speaker 2: of spiders, which they cram in these cylinders by the dozen.
Speaker 2: If you've never seen this before, I highly recommend looking
Speaker 2: up some images on your favorite image search system, because
Speaker 2: it's grizzly. These chambers are just filled with the remains
Speaker 2: of spiders because they need to be in there so
Speaker 2: that the young can hatch in or on these spiders
Speaker 2: and then consume their precious meat. Now an interesting wrinkle
Speaker 2: considering mud wasp nests, however, is that, as you may
Speaker 2: have noticed, while they'll naturally build their nests on naturally
Speaker 2: occurring wood or naturally occurring rock conditions, human structures of
Speaker 2: varying styles and materials often offer great environments for them,
Speaker 2: particularly you know, if it's something that's exposed to the
Speaker 2: elements at all, if it's open at all, so barns
Speaker 2: sheds this sort of thing. These are often significantly encrusted
Speaker 2: in mud wasp nests, to the point that someone may
Speaker 2: have to come around eventually and scrape them off. I
Speaker 2: think I've even seen them form on window panes, that
Speaker 2: sort of thing. In some cases, they're even building their
Speaker 2: own mud dwellings on human dwellings or creations that are
Speaker 2: made out of mud or stone or earth of some sort.
Speaker 2: And they've been doing this for a very long time.
Speaker 2: In fact, as pointed out by Finch at All in
Speaker 2: a twenty nineteen paper I was looking at in coordinary geochronology,
Speaker 2: the radiocarbon dating of these nests, when attached to things
Speaker 2: like ancient human rock art and relatively open rock dwellings,
Speaker 2: can be incredibly insightful. So we're talking like late Plustocene
Speaker 2: nests here, which have fossilized. The primary innovator of this
Speaker 2: approach with an Australian geochronologist named Richard Burt Roberts Bird
Speaker 2: being like the nickname you can call him bird apparently,
Speaker 2: and the hope was that given the wide world distribution
Speaker 2: of mud wasps, this would become something of like a
Speaker 2: standard tool for dating, you know, certain sites of archaeological interests.
Speaker 2: I've read some other papers that seem to indicate that
Speaker 2: this didn't quite come to pass. There might actually be
Speaker 2: limited practical value, but it's still pretty interesting and apparently
Speaker 2: maybe in some cases can be incredibly insightful when dating
Speaker 2: something of conditions are just right, all right. So that's
Speaker 2: some added detail on a case of an organism using
Speaker 2: mud that, again I think a lot of us are
Speaker 2: familiar with due to the distribution of mud wasps, and also,
Speaker 2: you know, is a fairly safe thing to encounter as
Speaker 2: a kid. But an example I wasn't familiar with concerns
Speaker 2: fiddler crabs.
Speaker 3: Oh interesting, now, if I recall, fiddler crabs played a
Speaker 3: big role in our series called The Lesser of Two
Speaker 3: Crab Claws about asymmetry and nature.
Speaker 2: Yeah, yeah, and here they are once more or at
Speaker 2: least two species of fiddler crab. Anyway, So I was
Speaker 2: reading about this in a two thousand and three article
Speaker 2: by Christy at All published in Behavioral Ecology and Sociobiology,
Speaker 2: and they pointed out that you have there are couple
Speaker 2: of key examples of fiddler crabs that do something interesting
Speaker 2: with the materials that they bring out of their burrows.
Speaker 2: So obviously one of the things about digging a burrow
Speaker 2: is you got to bring all that dirt up right.
Speaker 2: It's kind of like in the movie The Great Escape,
Speaker 2: What do you do with all that extra dirt from
Speaker 2: digging the tunnels. You can't just step in one place
Speaker 2: because then the guards will notice. So you've got to
Speaker 2: sneak it around. You've got to put it in the
Speaker 2: cuffs of your pants and secretly deposit it just all
Speaker 2: over the yard.
Speaker 3: Man, how much dirt can you fit in the cuff
Speaker 3: of your pants.
Speaker 2: Well, a little bit at a time, or as much
Speaker 2: as possible at a time to try to avoid detection.
Speaker 2: But you know, the crabs don't have to worry about that.
Speaker 2: So the crabs bring these materials out of the burrow,
Speaker 2: and in a couple of species, you see male fiddler
Speaker 2: crabs essentially to some degree, building something out of it
Speaker 2: next to their burrow. For instance, there's the musical fiddler crab.
Speaker 2: This is Leptusa Musica, and this one will build what
Speaker 2: it's called a sand hood next to the burrow. So
Speaker 2: this is just like I mean, picture kind of like
Speaker 2: a pile of sand. The image that I found of it,
Speaker 2: it looks kind of like a wave though it's kind
Speaker 2: of like a sale made out of piled sand. It's
Speaker 2: roughly the same height as the crab.
Speaker 3: I think of it as sort of a popped collar
Speaker 3: around the neck hole of the burrow entrance.
Speaker 2: Yeah, yeah, I think that's reasonable. Now you would be
Speaker 2: fair and saying, well, that sounds a lot like sand
Speaker 2: significantly less like mud guys. But don't worry. There's another one,
Speaker 2: and this is Bbe's Fiddler Crab. Bbe's Fiddler Crab sometimes
Speaker 2: builds mud pillars next to their burrows, and this seems
Speaker 2: to help them attract females for mating. Now, as the
Speaker 2: authors point out here, this is where it's more interesting
Speaker 2: is apparently females do seem to prefer going over and
Speaker 2: hanging out near males and burrows that have a mud tower,
Speaker 2: or in the case of the musical fiddler Crab, that
Speaker 2: sand hood. They do seem to prefer it, but the
Speaker 2: practice might not have evolved for mate choice. So, in
Speaker 2: other words, a lot of times things like this occur,
Speaker 2: and we talk about it being like a signal of fitness,
Speaker 2: like saying, look, I mean clearly I'm the one to
Speaker 2: mate with because look what I have throught, you know,
Speaker 2: look at this thing that I can Look how much
Speaker 2: sand I can pile up? Right, And that seems to
Speaker 2: be kind of like our basic way of understanding it.
Speaker 2: They argue in this paper that it may serve. These
Speaker 2: may serve as sensory traps providing shelter for crabs, which crabs,
Speaker 2: you know, crave to avoid predators. If you've ever walked
Speaker 2: around on the beach, you know how this works. The
Speaker 2: crab doesn't really want to be moving out in the
Speaker 2: open for long. It prefers to stick to to crevices
Speaker 2: and shadows because they're and of course holes and burrows
Speaker 2: could because there's safety there. And so the idea here
Speaker 2: is that selection pressure emerges out of the increased survivability
Speaker 2: of shade building male fiddler crabs. So the fiddler crabs
Speaker 2: that have have their sand or their mud piled in
Speaker 2: such a way as to allow for a little extra shade,
Speaker 2: a little extra shelter for themselves and for females they
Speaker 2: might be mating with, these are the ones that tend
Speaker 2: to survive.
Speaker 3: Okay, so not just a mate signal, but an actual,
Speaker 3: actually useful for survival.
Speaker 2: Right right, Yeah, And I think they're Their argument, if
Speaker 2: I'm understanding them correctly, is that, yeah, it's it's more
Speaker 2: about that survivability than any kind of signal that they're
Speaker 2: sending out there, any kind of fitness signal, though, I mean,
Speaker 2: just as far as you know. I'm looking at these
Speaker 2: pictures and I think I can't stack sand or mud
Speaker 2: that high where it towers over me. I mean this
Speaker 2: one of the of Bebe's fiddler craft.
Speaker 3: You're thinking I should go mate with that crab.
Speaker 2: Well, no, I mean, I just admire. It's like, could
Speaker 2: I stack mud up in a pillar or a column
Speaker 2: that's twice as tall as I am? No, I would
Speaker 2: be crushed by the mud. Now, other factors are involved, obviously.
Speaker 3: Hats off to the fiddler crab, to the Bebe crab specifically.
Speaker 2: Yeah, all right. Mud, of course, is also a nest
Speaker 2: building ingredient. Various birds collect mud in addition to other
Speaker 2: elements to build their nest. Using the mud is kind
Speaker 2: of a you know, glue or mortar. Swallows are the
Speaker 2: best example of mud use in birds, but various birds
Speaker 2: use mud to some degree. But still, if you haven't
Speaker 2: seen a swallow nest, you should look at one. It
Speaker 2: looks a muddy mess. This is not the bird ness
Speaker 2: that your kindergarten teacher kept in a shoe box to
Speaker 2: show you.
Speaker 3: Now, this one looks like a real disaster if it
Speaker 3: gets wet.
Speaker 2: I should also, of course mention beavers once more. We
Speaker 2: did a series of episodes on beavers not too long ago.
Speaker 2: Beavers obviously also use mud in their constructions, which are
Speaker 2: made out of out of wood and mud for the
Speaker 2: most part. Yeah, but I want to get to the
Speaker 2: best example of a of a mud organism, organism that
Speaker 2: thrives on it and in it, and that is the
Speaker 2: mud skipper. So in the last episode we discussed mud
Speaker 2: as this intermediate environment that likely played a greater role
Speaker 2: in the evolution of land animals than we often consider, right.
Speaker 2: Was one of the things that I mentioned in the
Speaker 2: last episode is like you think of that that illustration,
Speaker 2: that simplistic illustration, and a lot of old science textbooks
Speaker 2: of the the of mortal organisms coming out of the
Speaker 2: water and taking the land, and it's generally, you know,
Speaker 2: it looks like it's at at your local park, or
Speaker 2: it looks like maybe it's at the beach or something.
Speaker 2: You know. I often think of also if that Treehouse
Speaker 2: with Horror episode where the creature crawls out of the
Speaker 2: water and Homer Simpson sets on it or steps on it,
Speaker 2: africat which one it.
Speaker 3: Is, I'm thinking of a fish with human feet like that,
Speaker 3: like Julius Caesar's horse in that drawing.
Speaker 2: Yeah, but like we discussed like these kind of these
Speaker 2: these muddy environments, muddy waters and muddy shores and mud flats,
Speaker 2: they were. They were probably a lot more important than
Speaker 2: we often give them credit. And even today, when you
Speaker 2: consider the mud flats found in coastal wetlands around the world,
Speaker 2: you'll find vital ecosystems that are home to various specialized organisms.
Speaker 2: And yeah, the mud skipper is a mud specialist. You
Speaker 2: may like to go mudding, but the mud skipper lives
Speaker 2: in the mud. This is the mud skipper's world.
Speaker 3: You're in my world now.
Speaker 2: Yeah. So there are twenty three extended species of mud skipper.
Speaker 2: They're members of the vast Gabba dat family. More than
Speaker 2: two thousand species and more than two hundred genera, though
Speaker 2: I've seen that count lower as well, but it's still
Speaker 2: a lot. There are a lot of Gobi's in the world,
Speaker 2: but Gobi's, you know what I'm talking about. Most of
Speaker 2: you probably do. Gobi's. They have kind of a telltale
Speaker 2: look right their heads, their overall morphology they look like Gobi's.
Speaker 2: There's kind of I don't know how else to explain it.
Speaker 2: They all kind of look like they're saying, hey, guys,
Speaker 2: what's going on exactly? Yeah, there's a I think there's
Speaker 2: some gobies on SpongeBob like. They're very Spongebobby in their appearance. Now,
Speaker 2: they're fifteen genera of air breathing gobi's. But the mud
Speaker 2: skippers here in particular, belong to the genus Periophthalmus, and
Speaker 2: they have several defining features of note here that aid
Speaker 2: them in their their their muddy habitat. So, first of all,
Speaker 2: they have fused pelvic fins which form a disc shaped
Speaker 2: sucker which them by allowing them to sort of attach
Speaker 2: to surfaces. They can use these to aid themselves in
Speaker 2: climbing rocks and even trees. Namely, now we're talking about
Speaker 2: mangroves here, but we're talking about their roots, their trunks,
Speaker 2: their lower branches. So definitely a case of a fish
Speaker 2: that can climb a tree.
Speaker 3: Wouldn't have thought that.
Speaker 2: But of course, this is not the only gobi that
Speaker 2: excels at climbing. There's also a gobi that you will
Speaker 2: find in Hawaii if you visit certain waterfalls that I
Speaker 2: don't know if you'll get to see one. I didn't
Speaker 2: get to see one, but I mean you can you
Speaker 2: know they're there, or they're there sometimes there. These are
Speaker 2: the Oapu Nopili or Stimpson's Gobi, and these little guys
Speaker 2: scale the vertical cliffs of waterfalls.
Speaker 3: Wow.
Speaker 2: Yeah, you may have seen some videos, some documentary footage
Speaker 2: about these these creatures because they're they're amazing and it's
Speaker 2: an amazing journey, especially for something so small.
Speaker 3: You know, I knew about flying fish. I don't know why.
Speaker 3: I'm more impressed by climbing fish. I'm up trees and
Speaker 3: cliffs than i am with flying fish.
Speaker 2: So the coming back to the mud skipper though, Yeah,
Speaker 2: they have specialized morphology for semi aquatic living on these
Speaker 2: mud flats. They can breathe air through their skin and
Speaker 2: the lining of their mouth the only while wet. You
Speaker 2: often see images of them and footage of them with
Speaker 2: them with their mouths opening and so forth. They also
Speaker 2: do this as part of like a defensive display between males.
Speaker 2: It's a lot of great footage of that of these
Speaker 2: males combating each other and having standoffs on the mud.
Speaker 2: They are excellent soft sediment burrowers as well. They're great
Speaker 2: at burrowing in the mud. This is key to their
Speaker 2: egg laying. They build these burrows, they lay their eggs
Speaker 2: in the mud. Also, this is how they avoid predators.
Speaker 2: They jump down those burrows get out of sight of
Speaker 2: anything that's trying to eat them. And they also use
Speaker 2: these for thermoregulation as well. They also work to maintain
Speaker 2: an air pocket inside the burrow for prolonged stays in
Speaker 2: low oxygen environments. And you might wonder, too, well, how
Speaker 2: do they bring the mud back up? While they bring
Speaker 2: it up in their mouths, They bring big mouthfuls and
Speaker 2: they spit out these mud balls beside the burrow. Joe
Speaker 2: I included an image of a mud skipper spitting mud
Speaker 2: sort of a ball. It's not as cartoon cartoonally ball
Speaker 2: like as you might imagine, but here's a mud skipper
Speaker 2: spit and mud.
Speaker 3: So this is the equivalent of you're digging a hole
Speaker 3: in the ground with the shovel, you're throwing the mud,
Speaker 3: or not the mud, the dirt over your shoulder. Here
Speaker 3: it is digging in this wet mud, a sort of
Speaker 3: tunnel in the mud, and it is spitting out the
Speaker 3: excess that's being voided from the cavity.
Speaker 2: It's making exactly. Yeah. The other interesting thing about them,
Speaker 2: like their morphology positions, their eyes atop their head. They
Speaker 2: have these big eyes that you might not catch what
Speaker 2: it is. It's amazing about them when you're watching them.
Speaker 2: That makes them somehow more relatable and more human like.
Speaker 2: And part of that is is that they blink. Uh,
Speaker 2: they've and they evolved this independently of terrestrial tetrapods.
Speaker 3: Well, I said this about Gobi's earlier in general, but
Speaker 3: the yeah, the mud skippers do seem relatable in a
Speaker 3: way that a lot of fish don't.
Speaker 2: Yeah, and they're just yeah, they're they're crawling around on
Speaker 2: the mud flats. They're engaging in these standoffs with each other.
Speaker 2: And I think the other part is like, unlike a
Speaker 2: fish in the water, of course, in this case, they
Speaker 2: are also interacting, you know, on on a surface. They're
Speaker 2: they're they're out of that three d uh marine environment
Speaker 2: and here they are on the mud behaving as these
Speaker 2: strange creatures that that you know, that almost feel very
Speaker 2: alien compared to anything else because they're they're they're not
Speaker 2: exactly like anything in the water, and they're not like
Speaker 2: anything on the land. Uh, They're they're totally doing their
Speaker 2: own thing, and they're doing it in this strange, like muddy,
Speaker 2: kind of slimy environment.
Speaker 3: I mean, I guess they look like a cross between
Speaker 3: fish and frogs, which makes sense because they are amphibious fish.
Speaker 2: Yeah. I want to say, it's BBC's Life, one of
Speaker 2: the David Attenboroughs that has some tremendous footage of these
Speaker 2: guys going about their business. And I think they even
Speaker 2: used to they put a camera down in one of
Speaker 2: their burrows so you can see how that's going. Some
Speaker 2: really remarkable footage that's from probably at least ten years
Speaker 2: old now, but it's out there.
Speaker 3: See how it's going.
Speaker 2: Yeah, it's going. It's going great down there.
Speaker 3: Now we're the ones saying, hey, guys, what's up?
Speaker 2: Yeah? All right?
Speaker 3: Should we call it there for part two?
Speaker 2: Yeah? I think so. I mean, I think that's a
Speaker 2: good overview of some of the ways that animals use mud,
Speaker 2: like most of the major categories of mud use and
Speaker 2: some of the more exciting and notable cases. I'm sure
Speaker 2: we left off some interesting ones. So if there's one
Speaker 2: that you really love, just right in let us know.
Speaker 2: We'll highlight it, perhaps in a future episode of Listener. Mail,
Speaker 2: because yeah, it's the realm of mud. Is this world
Speaker 2: that is easy. It's easy for us to take it
Speaker 2: for granted and not realize just how versatile it is
Speaker 2: and how essential it is for various organisms. So we're
Speaker 2: going to have at least one more episode regarding mud
Speaker 2: this Thursday. Tune in for that. This is going to
Speaker 2: be the one where we're going to come back and
Speaker 2: discuss mud and warfare a little bit, but we're also
Speaker 2: going to discuss the importance of mud as a human
Speaker 2: construction material or the creation of mud bricks and so forth.
Speaker 2: In the meantime, if you would like to listen to
Speaker 2: other episodes of Stuff to Blow Your Mind, you will
Speaker 2: find them in the Stuff to Blow your Mind podcast
Speaker 2: feed We have our core episodes on Tuesdays and Thursdays,
Speaker 2: listener Mail on Monday, short Form Artifact or Monster Fact
Speaker 2: on Wednesday, and on Fridays, we set aside most series
Speaker 2: concerns to just talk about a weird film on Weird
Speaker 2: House Cinema.
Speaker 3: Huge thanks to our excellent audio producer JJ Posway. If
Speaker 3: you would like to get in touch with us with
Speaker 3: feedback on this episode or any other to suggest a
Speaker 3: topic for the future, or just to say hello. You
Speaker 3: can email us at contact Stuff to Blow Your Mind
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