Speaker 1: Hey, welcome to Stuff to Blow your Mind. This is
Speaker 1: Robert Lamb. Today is Saturday, so we have an older
Speaker 1: episode of Stuff to Blow Your Mind to share with
Speaker 1: you here. This one was originally published eight thirteen, twenty
Speaker 1: twenty four. It is Blood Squirting from the Lizard's Eye,
Speaker 1: Part one.
Speaker 2: Welcome to Stuff to Blow Your Mind, production of iHeartRadio.
Speaker 1: Hey, welcome to Stuff to Blow your Mind. My name
Speaker 1: is Robert Lamb.
Speaker 3: And I am Joe McCormick. And today on Stuff to
Speaker 3: Blow Your Mind, we are going to be talking about
Speaker 3: an animal, about the horned lizard or frenosoma, a genus
Speaker 3: of lizard native to North America, also known as horned
Speaker 3: toads or horny toads. From what I've been reading, I
Speaker 3: think the people in the biological sciences prefer the more
Speaker 3: accurate lizard, applely because they are certainly not toads, though
Speaker 3: there are reasons for calling them toads, mainly that they
Speaker 3: look like toads.
Speaker 1: Now, we're going to probably try and stick to horned lizard.
Speaker 1: I'm probably going to say horned lizard because I like
Speaker 1: using the more antiquated term and it sounds more demonic.
Speaker 1: But we also might say, horny toad, horned toad, horn toad,
Speaker 1: and so forth.
Speaker 3: Throughout the episode, Horned Lizard makes me think learned lizard.
Speaker 3: You know, doesn't it suggest a kind of wisdom?
Speaker 1: Yeah? Yeah, sometimes lizards can appear quite wise, so I
Speaker 1: buy that.
Speaker 3: And in fact, you might even think about some of
Speaker 3: the species of horned lizards as especially wise or discerning
Speaker 3: among the reptile kind, because they, as we get into
Speaker 3: later in this episode, they have some anti predator strategies
Speaker 3: that really require snap judgment calls about say what type
Speaker 3: of predator you're dealing with?
Speaker 1: That's right? And I don't know if we'll get into
Speaker 1: it in this episode or the next, but among the Navajo,
Speaker 1: among the DNA people, they're sometimes called grandfather, so I
Speaker 1: think there is often that vibe of maybe sort of
Speaker 1: wisdom and power to them.
Speaker 3: Though I have to admit I did come to this
Speaker 3: topic through more base and if you know, us predictable routes.
Speaker 3: So my window into talking about horned lizards was the
Speaker 3: fact that for sci fi horror nerds like us, it's
Speaker 3: alien summer. Would you agree, Rob.
Speaker 1: Oh, yeah, it's been an alien summer for me. We've
Speaker 1: been chatting about alien movies and the upcoming alien movie.
Speaker 1: So yeah, there's a lot of excitement in the air.
Speaker 3: Yeah, there's a new alien movie coming out in theaters
Speaker 3: later this week, Alien Romulus. Of course, there's no guarantee
Speaker 3: ahead of time it's going to be good. I don't
Speaker 3: think they've even released the critics embargo yet. But I'm
Speaker 3: just recklessly letting myself get excited regardless tempering expectations is
Speaker 3: for the week.
Speaker 1: That's right, Say yes to Xenomorph and then figure the
Speaker 1: rest out later.
Speaker 3: You know, if I'm disappointed, I'm disappointed, It'll be okay.
Speaker 3: So we've had Aliens on the brain for a few
Speaker 3: months here, and we've covered a couple of Aliens copycat
Speaker 3: movies on Weird House Cinema. We'll probably do at least
Speaker 3: one more, I think that's right.
Speaker 1: We also had a seven part Monster Fact series on
Speaker 1: the various creatures and organisms of the alien universe, with
Speaker 1: part seven publishing this week.
Speaker 3: Mm hmm. But so we've got all this excitement running
Speaker 3: through us, and I was looking to find some real
Speaker 3: world biology to cover that had parallels an alien. We've
Speaker 3: already done a lot of topics along these lines in
Speaker 3: the past, and the idea of the xenomorph's weaponized blood
Speaker 3: took hold. So in the Alien movies if you haven't
Speaker 3: seen them, the creature in these movies has extremely potent
Speaker 3: acid for blood, which appears to serve as a defense strategy.
Speaker 3: So if you cause injury to one of the Xenomorphs,
Speaker 3: you are likely to get some of its blood on
Speaker 3: yourself or on your critical infrastructure, such as the inside
Speaker 3: of your spacecraft hull, and that blood will burn through
Speaker 3: bodies and space ships alike. So, as observed by the
Speaker 3: characters in the first movie, there's real danger in injuring
Speaker 3: the creature. How do you fight it?
Speaker 1: That's right. It's also worth pointing out that there is
Speaker 1: at least some acid fluid as projectile in the xenomorph world.
Speaker 1: The most, I would say, I guess the key example
Speaker 1: would be in nineteen seventy nine's Alien the first film,
Speaker 1: as we see that emergent face hugger seem to use
Speaker 1: acidic secretions to burn through Caine's helmet in order to
Speaker 1: access his face. Now, naturally, given that certain wounds, especially
Speaker 1: lethal wounds to a Xenomorph, could result in a jet
Speaker 1: of acidic blood, we could easily classify that as a
Speaker 1: form of defensive spray, and then in Alien three and
Speaker 1: Alien Resurrection, the third and fourth movies in the franchise,
Speaker 1: we actually see xenomorphs using an offensive acid spray attack,
Speaker 1: And of course this has also been used to various
Speaker 1: effects in Alien video games for ranged enemies, as well
Speaker 1: as in Alien comic books and so forth. Also worth
Speaker 1: pointing out that, given our current Mortal Kombat discussions on
Speaker 1: Weird House Cinema, the acid spit is one of the
Speaker 1: signature moves of the green clad Ninja reptile.
Speaker 3: Is it really a spit because the animation looks to
Speaker 3: me more like projectile vomit.
Speaker 1: I think it depends. At least in the first game.
Speaker 1: He was in Mortal Kombat too, he would definitely spit.
Speaker 1: It was like a kind of a sound over and
Speaker 1: over again, and I think it got a little more
Speaker 1: vomity later on.
Speaker 3: Okay, Now, of course, it's fairly common in the natural
Speaker 3: world to find animals that produce some kind of toxic
Speaker 3: defensive fluid that they use to protect themselves against predators
Speaker 3: or attack prey. But what seemed less common, though perhaps
Speaker 3: more common than you would think, was that the defensive
Speaker 3: fluid in question was actually the animal's own blood.
Speaker 1: That's right, because a part of the logic here, of course,
Speaker 1: is we tend to think vampire like when we think
Speaker 1: about an organism's blood. Right, it's part of the prize,
Speaker 1: it's part of the predator's claim. So broadly speaking, it would,
Speaker 1: on the surface anyway, seem illogical to think that a
Speaker 1: predator could be harmed by blood of its prey.
Speaker 3: But here is where the horned lizard comes in. If
Speaker 3: you know one thing about the horned lizard, it is
Speaker 3: probably that these various species of lizards have a defensive
Speaker 3: adaptation of squirting blood out of their eyes.
Speaker 1: That's right. They're kind of Internet famous for this, a
Speaker 1: lot of clips, a lot of a lot of animations
Speaker 1: and videos. I should also add that if you know
Speaker 1: one thing, you should probably know two things. Also, that
Speaker 1: there to some extent horned up, right, because right, I
Speaker 1: call them horned lizards, right.
Speaker 3: But while lots of animals are spiky or horned in
Speaker 3: some way, I would say that the blood squirting out
Speaker 3: of the eyes is such a shocking behavior, such a
Speaker 3: bizarre and seemingly rare adaptation, that you would almost have
Speaker 3: to wonder if it's not real, Like, is that something
Speaker 3: people just made up or does that really happen? And
Speaker 3: according to the author of a book that I'm going
Speaker 3: to cite in this episode, reports of it have sometimes
Speaker 3: in the past been dismissed as tall tales, but they're
Speaker 3: not tall tales. The Horned Blizzard's weaponized blood is absolutely real,
Speaker 3: and it is the subject of some interesting scientific investigation.
Speaker 1: So this is going to be really fun to get
Speaker 1: into now. When we were doing our pre research, though, Joe,
Speaker 1: you brought up a resource that we've looked to in
Speaker 1: the past, and that's the California herbs dot com website
Speaker 1: where they have a wonderful I mean it's not just
Speaker 1: about this, but they have a huge listing of various
Speaker 1: herp appearances in various films, many of which are very
Speaker 1: much in the domain of weird house cinema meaning reptiles, yes, yeah, yeah,
Speaker 1: for herpetologist cinema files. And they have a list there
Speaker 1: that you shared with me of horned lozerds in movies,
Speaker 1: and there are a few that I was familiar with,
Speaker 1: you know, because they're pretty popular films. I think what
Speaker 1: outlot Josie Wales is on there.
Speaker 3: Yeah, but they they are apparently a number of you know,
Speaker 3: westerns I guess where there are horned lizards, which makes
Speaker 3: sense because you know, you find a lot of these
Speaker 3: several of these species are very common in the American Southwest.
Speaker 1: But also Jodroowski's Holy Mountain is included there, his film
Speaker 1: from nineteen seventy three that does have a very memorable
Speaker 1: hert scene, though it may contain shots of actual hurts
Speaker 1: being exploded with fireworks, so you know, go into that
Speaker 1: one with a certain amount of caution. But it's I mean,
Speaker 1: it's Holy Mountains, so I'd advise a great deal of
Speaker 1: content consideration before you watch it. Anyway, It's kind of
Speaker 1: a titan of surreal cinema and an important film when
Speaker 1: you're looking at weird psychotronic pictures and you know, Mexican
Speaker 1: cinema certainly cinema of the nineteen seventies. But it is
Speaker 1: not for everyone.
Speaker 3: Yeah, that's not movie Night with the grandparents.
Speaker 1: Yeah, I believe the scene in question. It's been a
Speaker 1: long time since I've seen it, and I have only
Speaker 1: seen it like used to. The only way you could
Speaker 1: watch it would be like a rip of a Japanese
Speaker 1: laser disc, and they're much better sources for it available now,
Speaker 1: But there is an extended scene where the conquest of
Speaker 1: Mexico is recreated with frogs and toads and lizards standing
Speaker 1: in for the various actors and sides in this conflict.
Speaker 3: I did not remember that detail. There's a lot I've
Speaker 3: forgotten about Holy Mountain.
Speaker 1: So I would say cameo appearance by the horned lizard. Now,
Speaker 1: it's worth noting at the top here that we're not
Speaker 1: dealing with a single species when we're discussing horned lizards,
Speaker 1: but rather an entire genus of North American lizards, and
Speaker 1: that's Phinosoma, including some twenty one species which range as
Speaker 1: far north as parts of Canada and on the southern
Speaker 1: end range all the way through Mexico and into Guatemala.
Speaker 1: And of these again, somewhere around twenty one species, at
Speaker 1: least eight species squirt blood from the eye region. So
Speaker 1: just an example of range here, there's the greater short
Speaker 1: horned lizard or Hernandez is short horned lizard, and it
Speaker 1: can be found as far north as southern Saskatchewan and
Speaker 1: Alberta and south into the Texas Panhandle in central Mexico.
Speaker 1: And this is one of the species of bloodshooters.
Speaker 3: Yeah, that's right. But as you said, Rob, the various
Speaker 3: species of horned lizards can be found all over the
Speaker 3: part of North America, from down in southern Mexico all
Speaker 3: the way up to the southern part of Canada. And
Speaker 3: you can look up maps that show you sort of
Speaker 3: different estimated ranges of the different species. But yeah, you'll
Speaker 3: find them all throughout the arid and semi arid regions
Speaker 3: of the North American West. Here, I think it would
Speaker 3: be a good place to introduce one of my major
Speaker 3: sources for this episode, which is a book called Introduction
Speaker 3: to Horned Lizards of North America by Wade C. Sherbrook.
Speaker 3: This was published by University of California Press in two
Speaker 3: thousand and three, and the author, Wade Sherbrooke, was director
Speaker 3: of the Southwestern Research Station of the American Museum of
Speaker 3: Natural History, and so one of the questions Sherbrooke addresses
Speaker 3: in the introduction of this book is why are horned
Speaker 3: lizards commonly referred to as toads, horned toads, horny toads. Well,
Speaker 3: they really do kind of look like toads. They tend
Speaker 3: to have a wide body when viewed from above, especially
Speaker 3: in certain defensive postures where they sort of flatten and
Speaker 3: widen their bodies out to create to sort of turn
Speaker 3: their backs into a shield. They tend to for lizards
Speaker 3: have a short, blunt snout which can resemble a toad's head,
Speaker 3: and they also have an awkward walking gait. They tend
Speaker 3: to have a camouflaged appearance which helps them blend into
Speaker 3: their often sandy or gravelly surroundings, and this can resemble
Speaker 3: the model color patterns and bumpy texture you would see
Speaker 3: on the backs of some toads, so in lots of
Speaker 3: different ways they look like toads, and this led to
Speaker 3: the name of their genus. Frinosoma means toad body, phrenoss
Speaker 3: toad and soma of course means body, toad body, total
Speaker 3: toad body to add to the toad comparisons to make
Speaker 3: them even more of a toad body. Can observe how
Speaker 3: they eat. Now, the different species of horned lizards have
Speaker 3: some different different diets. Some are more sort of taking
Speaker 3: what they can get than others, but some are quite
Speaker 3: specialized to eating insects and specifically ants, specifically even more
Speaker 3: harvester ants. And if you watch the horned lizards eat
Speaker 3: harvester ants. When they specialize in this food source, they
Speaker 3: have a kind of a sticky, flicking tongue action, much
Speaker 3: like we associate with toads and frogs. I was reading
Speaker 3: in one part of the Sherbrook book about how exactly
Speaker 3: it is that these horned lizards can eat these incredibly
Speaker 3: venomous ants, and apparently they have a strategy of like
Speaker 3: flicking them into the mouth, and then as they swallow
Speaker 3: the ant, the ant becomes covered in this layer of
Speaker 3: mucus that comes out of glands in the lizard's throat,
Speaker 3: and this coating of mucus surrounds the ant as the
Speaker 3: ant is is digested and essentially disables it from biting
Speaker 3: or stinging the lizard from the inside until it is
Speaker 3: well dead and able to be digested. And these lizards
Speaker 3: have to eat a lot of these ants because ants
Speaker 3: are not super nutritious like they've got There's not a
Speaker 3: lot of meat on that bone. It's mostly bone.
Speaker 1: That's right. Like For instance, one of the other big
Speaker 1: ant eaters out there is of course the mammalian ant eater,
Speaker 1: and they are known to eat tons of ants and termites.
Speaker 1: I've seen estimates of like thirty thousand ants and termites
Speaker 1: a day, But even that is still a low calorie diet,
Speaker 1: and it's one of the reasons that we think that
Speaker 1: ant eaters have one of the lowest mammalian body temperatures.
Speaker 1: But in terms of the the what we're dealing with here,
Speaker 1: the horned lizards consumption of ants, I found an interesting
Speaker 1: article that answers the question, well, how do they eat
Speaker 1: them safely? This was from two thousand and eight published
Speaker 1: in the journal jazz A by Sherbrooke and Schwink, And
Speaker 1: the answer is in the title Horned lizards Incapacity Dangerous
Speaker 1: ant prey with mucus. And we've already touched on the
Speaker 1: main aspect of this, but they provide one more little
Speaker 1: detail that I really like. They write, quote, we show
Speaker 1: that they're derived feeding kind of mattics that are associated
Speaker 1: with unique mucus secreting hyrngel papilia that apparently serve to
Speaker 1: immobilize and incapacitate dangerous ants as they are swallowed by
Speaker 1: compacting them and binding them in mucus trans And then
Speaker 1: they later add the detail ants extracted from fresh killed
Speaker 1: horned lizard's stomachs are curled ventrally into balls and bound
Speaker 1: in mucus.
Speaker 3: Take an ant as you're swallowing it, coat it with slime,
Speaker 3: and wadd it up into a ball so that you
Speaker 3: can digest it without it getting into trouble inside your
Speaker 3: digestive tract. That's right, Roll them up, all right, So
Speaker 3: that is horned lizards as predators. But I wanted to
Speaker 3: focus for the majority of today's episode on horned lizards
Speaker 3: as prey because it is, of course in their role
Speaker 3: as prey and in their anti predator defense strategies that
Speaker 3: we see the jets of blood emerge from the eyes.
Speaker 3: So here I want to go back to that book
Speaker 3: I mentioned by Wade Sherbrook. He has an excellent section
Speaker 3: in this book called Enemies and Defense, which sort of
Speaker 3: covers a nearly comprehensive list of different sort of predator
Speaker 3: prey relationships between horned lizard species and the predators that
Speaker 3: target them, and the strategies they have for resisting these predators. So,
Speaker 3: as we alluded to earlier, horned lizards are of course
Speaker 3: covered in spikes and scales. This is a pretty sophisticated
Speaker 3: armor defense. If you've never seen what a horned lizard
Speaker 3: looks like by the way, you should look one up.
Speaker 3: I mean, first of all, they are beautiful, but this
Speaker 3: will give you a better idea of what we're talking
Speaker 3: about as we continually reference the armour moving on. They
Speaker 3: tend to have spikes and scales along different parts of
Speaker 3: their bodies, such as sort of spiky flank protrusions running
Speaker 3: down the lateral sides of the body, but then also
Speaker 3: sometimes some kind of bumpy or tough coverings on the back,
Speaker 3: and then especially bony spike protrusions around the crown of
Speaker 3: the head. So some of the spiky looking things, usually
Speaker 3: the smaller ones are just more modified scales, but the
Speaker 3: spikes around the head are actually like hard, sharp bony
Speaker 3: spikes now covered in spikes and scales. As they are,
Speaker 3: you might not think that a horned lizard would look
Speaker 3: very appetizing, but you know, out here in the arid
Speaker 3: and semi arid regions of the American West, many predators
Speaker 3: will take whatever they can get, and so horned lizards
Speaker 3: are indeed a prey animal to many species of predators.
Speaker 3: Juveniles are the most vulnerable to predation. They're smaller and
Speaker 3: they have less developed armor, so many are eaten between
Speaker 3: the time they hatch from their eggs and the first hibernation.
Speaker 3: But Sherbrooke in this chapter gets into a list of
Speaker 3: different predators, and the first one I want to look
Speaker 3: at is his section on the long nosed leopard lizard
Speaker 3: or the Gambelia whizly zennii. These are worth looking up
Speaker 3: a picture of as well, because while they're not very
Speaker 3: interesting in terms of shape, they're just sort of like
Speaker 3: larger looking predatory lizards. They do have a truly leopard
Speaker 3: looking coloration pattern.
Speaker 1: Yeah. Yeah, they're quite quite fetching in their own right.
Speaker 3: So these lizards will frequently attack and eat horned lizards,
Speaker 3: especially juveniles, and the general strategy here is not super complicated.
Speaker 3: It is to bite them near the head and then
Speaker 3: swallow them whole head first. You know, this is just
Speaker 3: me reasoning from the pictures, but the sort of backwards
Speaker 3: pointing orientation of the head spikes, because they sort of
Speaker 3: extend backward from the head like a crown, it makes
Speaker 3: it seem like it would probably be easier to swallow
Speaker 3: a horned lizard head first rather than tail first, Like
Speaker 3: if you went backwards, I would think the spikes would
Speaker 3: would be more likely to catch like hooks in the
Speaker 3: lining of the throat and the digestive system. But it
Speaker 3: also seems like eating one of these things head first
Speaker 3: would be a very no going back scenario. You know,
Speaker 3: once you start eating a big one, you're committed.
Speaker 1: Yeah, yeah, you can't put it in reverse.
Speaker 3: Sherbrook says in the book about defensive strategies that when
Speaker 3: attacked by a leopard lizard a horned lizard, and again,
Speaker 3: defensive strategy is very somewhat by species, so we'll be
Speaker 3: speaking in some generalities here, but the horned lizard will
Speaker 3: often try to defend itself by flattening out its back
Speaker 3: into a wide shield shape so it wants to look
Speaker 3: as wide as possible, and then tilting and orienting its
Speaker 3: armored shield back toward the predator. And again, adults with
Speaker 3: well developed armor are much less vulnerable to leopard lizards.
Speaker 3: The next category is birds. A number of different birds
Speaker 3: prey on horned lizards. Sherbroke mentions hawks such as the
Speaker 3: red shouldered hawk or buteolineatis, but also smaller birds like
Speaker 3: the prairie falcon, the American kestrel, and the loggerhead shrike.
Speaker 3: Predatory birds with powerful talons and beaks have an advantage
Speaker 3: when preying on these lizards because they have the ability
Speaker 3: to tear the lizard apart and eat it piece by piece,
Speaker 3: making it a somewhat easier proposition to consume that this
Speaker 3: spiky animal as opposed to an armored adult that needs
Speaker 3: to be swallowed whole. However, it does still come with risks.
Speaker 3: Sherbrooke mentions one case of a red shouldered hawk that
Speaker 3: was found dead after having eaten a couple of Texas
Speaker 3: horned lizards. Apparently one of the horns had pierced through
Speaker 3: the hawk's throat from the inside. Oh, and I can't
Speaker 3: help but apply like a human level of grossed out
Speaker 3: to this. Like I know it's just part of the
Speaker 3: you know, their way of making a living, but I
Speaker 3: cannot imagine eating something this spiky.
Speaker 1: And it's like a like a like a wheat then,
Speaker 1: except even worse right.
Speaker 3: Yeah, Oh, it's like you know, you ever think when
Speaker 3: you're like eating a tortilla chip and you don't chew
Speaker 3: it upright and you get a shard caught in your throat. Yeah, Okay.
Speaker 3: Another bird that preys on these animals is the greater
Speaker 3: road runner or Geocossics californian Us. The Greater Roadrunner has
Speaker 3: an interesting strategy where it grabs the horned lizard by
Speaker 3: a leg or by the tail with its beak, and
Speaker 3: then it whips them up in the air and slams
Speaker 3: them back down against the ground repeatedly, so it is
Speaker 3: beating the lizard against the earth, using centrifugal force to
Speaker 3: smash it dead. Basically, it bashes it and bashes it
Speaker 3: until it is dead and busted up, and this allows
Speaker 3: the roadrunner to take its time orienting the lizard so
Speaker 3: it can be swallowed whole head first by attached to
Speaker 3: a picture for you of the Greater Roadrunner trying to
Speaker 3: get this whole lizard into its mouth head first that
Speaker 3: I don't know how this is going to happen. This
Speaker 3: is just a photo from the book. It's not animated,
Speaker 3: but I believe in you.
Speaker 1: Yeah, yeah, yeah, I mean, roadrunners are such interesting, weird
Speaker 1: creatures in their own ride. I don't feel like the
Speaker 1: cartoons properly prepared. As for the reality, I've only seen
Speaker 1: I've only seen them in the wild, I think one
Speaker 1: or two times while I'm in the Arizona. But it's
Speaker 1: like it's like seeing like the ghost of a dinosaur
Speaker 1: run by. It's pretty neat.
Speaker 3: Yeah yeah yeah. And of course, in the case of
Speaker 3: the roadrunner, swallowing it headfirst once again keeps the horns
Speaker 3: pointed away from the bird's vital organs. It's going down
Speaker 3: the digestive tract.
Speaker 1: Clever girl.
Speaker 3: Yeah yeah, okay, So another bird predator chiwawin ravens or
Speaker 3: corvas crypto. Lucas Sherbrook says that these birds, they've got
Speaker 3: an interesting difference here. They bring dead horned lizards to
Speaker 3: their nests to feed their young, but the ravens render
Speaker 3: them safe by not feeding them to their young hole,
Speaker 3: but instead ripping them open and only feeding the soft
Speaker 3: inerds to the hatchlings, so only guts for the children,
Speaker 3: and then the carcass with the hard parts is discarded.
Speaker 1: All right, Well, that's not surprised. Leave it to the
Speaker 1: ravens to intelligently dissect before feeding.
Speaker 3: To the end, they're like a tourist at a beach
Speaker 3: restaurant picking the meat out of a crab. They're getting
Speaker 3: all the juicy bits and not swallowing the hard parts.
Speaker 3: Of course, snakes are a major predator of these lizards.
Speaker 3: Various species of snakes prey on them, killing them either
Speaker 3: with venom or with constriction, and then in all cases
Speaker 3: swallowing them whole. Snakes, like birds, do incur some risk
Speaker 3: by attempting to swallow a horned lizard. Sometimes the horns
Speaker 3: rip them open from the inside, and a crucial factor
Speaker 3: seems to be just the relative sizes of the snake
Speaker 3: in the lizard. The snake, it's hung, but it can't
Speaker 3: get too greedy. It has to know its limits. And
Speaker 3: so I guess there are cases where a snake might
Speaker 3: be sort of driven near starvation and it's pushing the
Speaker 3: boundaries of like, is this thing so big it's going
Speaker 3: to kill me to eat it? I'm gonna roll the dice. Now,
Speaker 3: that's not all the potential predators of horned lizards, but
Speaker 3: I'm going to come back to one more major category
Speaker 3: in a minute when we get to the blood squirting.
Speaker 3: So there's another interesting framework that Sherbrook introduces in this
Speaker 3: chapter where he's talking about the different levels of defense
Speaker 3: that a prey animal can deploy when trying to survive
Speaker 3: against predators, and the three layers of defense he talks
Speaker 3: about are, first of all, avoid being seen second, avoid
Speaker 3: being caught, and third be difficult to eat or appear
Speaker 3: dangerous to the predator. And you could sort of paraphrase
Speaker 3: these as one, hide, two run in three fight. Horned
Speaker 3: lizards are not very good at number two. They're not
Speaker 3: very good at running away. There are some exceptions, such
Speaker 3: as when facing off against certain snakes venomous snakes like
Speaker 3: the diamondback rattle snake. Sometimes in facing off against one
Speaker 3: of those, the lizard will just run away, But in
Speaker 3: most cases it's not going to be great at trying
Speaker 3: to outrun predators. They've got kind of short limbs and
Speaker 3: awkward movements. So mostly horned lizards excel at number one
Speaker 3: and number three avoiding being seen in the first place.
Speaker 3: And then if they really if they're cornered and they're
Speaker 3: caught and they can't hide anymore, they resist being eaten
Speaker 3: somehow by a combination of morphological and behavioral defenses. So
Speaker 3: we'll look at number one first, the hiding part. Horned
Speaker 3: lizards are masters of camouflage, and Sherbrooke has an interesting
Speaker 3: side note about how we often don't appreci cate how
Speaker 3: effective a wild animal's camouflage actually is because most people,
Speaker 3: you know, if you're not like living out in the wilderness,
Speaker 3: most of the time you're going to see any of
Speaker 3: these wild animals, it's in some form of media that
Speaker 3: is designed to help you see the animals, such as
Speaker 3: like a picture in a book or footage in a documentary,
Speaker 3: where the whole point is that you're supposed to be
Speaker 3: able to see it. And so this kind of we
Speaker 3: kind of underappreciate how effective natural camouflage strategies are because
Speaker 3: if we were just walking around in the environment, we
Speaker 3: likely might go right by animals of this type and
Speaker 3: never see them, so we wouldn't even know that we'd
Speaker 3: miss them.
Speaker 1: That's a great point. Yeah, And so.
Speaker 3: Horned lizards are very good at hiding. They hide themselves
Speaker 3: with a couple of strategies. They hide by disrupting predator
Speaker 3: search routines for both shape and color, so their coloration
Speaker 3: tends to mimic the patterns of gravelly, sandy or grassy
Speaker 3: grounds where they live, and the pigment in their skin
Speaker 3: tends to match the color of the local soil or
Speaker 3: whatever the background is. So, for example, horned lizards that
Speaker 3: live in areas with redder soil will be redder in
Speaker 3: color and so forth. Also, in the domain of color,
Speaker 3: they have patterns of what is called disruptive coloration. This
Speaker 3: is found in many animals where varied color patterns make
Speaker 3: it harder to pick out the outline of an object
Speaker 3: against the background. This is also one of the main
Speaker 3: principles behind human tactical camouflage. Some of their hiding strategies
Speaker 3: are more obvious, like in some cases, if there is
Speaker 3: a predator around, they might increase their hiddenness by ducking
Speaker 3: underneath something so they can run under a shrub or
Speaker 3: a rock or some of the ground cover. But another
Speaker 3: thing they do often is if a predator is nearby,
Speaker 3: they can flatten their bodies against the ground, and this
Speaker 3: especially helps protect against, say, the visual detection by birds,
Speaker 3: because this flat prevents them from casting a shadow, which
Speaker 3: if they did cast a shadow, would reveal their outline.
Speaker 3: So if you can't see the outline of the creature,
Speaker 3: it disrupts the predator's shape recognition. And the horned lizard's
Speaker 3: lateral body spikes also help disrupt shape recognition by interfering
Speaker 3: with the casting of a shadow. Now, in order for
Speaker 3: a lot of these hiding strategies to be effective, the
Speaker 3: horned lizard needs to remain motionless, which it does much
Speaker 3: of the time. It pays to be sedentary if you're
Speaker 3: one of these buddies, and it also helps that you know,
Speaker 3: as ectotherms, they need to spend a lot of time
Speaker 3: absorbing sun anyway, because their body temperature is dependent on
Speaker 3: the surrounding environment, they don't generate their own body heat
Speaker 3: through metabolism. Now, one defensive strategy that Sherbrook talks about,
Speaker 3: which in a kind of embarrassing way ping done some
Speaker 3: like video game playing styles I'm familiar with, is that
Speaker 3: if startled, the horned lizard will often run as fast
Speaker 3: as it can a short distance and then suddenly stop
Speaker 3: and freeze. Why would it do that? That doesn't seem
Speaker 3: to make a lot of sense, but it does actually
Speaker 3: if you read it explained. So the lizard usually can't
Speaker 3: run very fast very far, but the main purpose of
Speaker 3: it seems to be too quickly re enter stealth mode,
Speaker 3: so you run a short distance and then freeze in
Speaker 3: order to once again blend into the surroundings and hopefully
Speaker 3: disappear from the predator's vision. This makes me think of
Speaker 3: various I don't know, like Batman, video games and stuff.
Speaker 3: Where the bad guys see you and this like, oh oh,
Speaker 3: I need to run to the opposite side of the
Speaker 3: room and hide, and then they'll all be like where'd
Speaker 3: he go?
Speaker 1: Or like a metal gear game where you just immediately
Speaker 1: put a box over your body and then they're looking
Speaker 1: right at you and maybe they won't see it. Huh.
Speaker 1: But you know, I have to say I only have
Speaker 1: human eyes. I don't have the eyes of an eagle,
Speaker 1: and they're not even great human eyes. But you know,
Speaker 1: there have been times where I've been watching an animal
Speaker 1: in the wild that is really good at its camouflage,
Speaker 1: and you know, either it will be the situation of
Speaker 1: looking right at it and not seeing it until there
Speaker 1: is movement, or the reverse kind of looking at it
Speaker 1: in movement and in the second it stops, I cannot
Speaker 1: see it anymore. I know it is there, but I
Speaker 1: cannot actually see it. It's just based on the memory
Speaker 1: of what just happened.
Speaker 3: So yeah, that's how it works for predators also. I
Speaker 3: mean it's again we underappreciate how effective camouflage can be
Speaker 3: because we're so trained on this, like media that shows
Speaker 3: you this is where it is, look right here. But okay,
Speaker 3: let's say all of that has failed. You Your invisibility,
Speaker 3: camouflage stealth mode has failed. You're a horned lizard and
Speaker 3: you're cornered by a predator that definitely knows you're here.
Speaker 3: Here we get to the active defail strategies, where you
Speaker 3: try to make yourself look difficult to eat or dangerous
Speaker 3: to the predator. Now, the range of behaviors described in
Speaker 3: Sherbrook's book here are surprisingly diverse. I wouldn't have expected
Speaker 3: this many different things to be on the record, but
Speaker 3: Sherbrook lists a number of them, just in response to
Speaker 3: the presence of humans. To read from a paragraph here
Speaker 3: quote in an almost comic antic, one horned lizard raised
Speaker 3: itself high on all four legs, lowered its head, and
Speaker 3: in a series of hops, approached its tormentor like a
Speaker 3: charging bull. On another occasion, a horned lizard charged and
Speaker 3: bit a person's boot. Normally, they do not bite when
Speaker 3: captured by hand, but some struggle an attempt to thrust
Speaker 3: their horns into the flesh of their captor. Now that's
Speaker 3: kind of interesting, though. There are also reports that a
Speaker 3: good number of these lizards, if picked up and handled
Speaker 3: and sometimes rubbed or stroked, they will become immobile, and
Speaker 3: this could be some kind of death feigning strategy, as
Speaker 3: seen in some prey animals. You might wonder, like, why
Speaker 3: would it be advantageous for a prey animal to pretend
Speaker 3: to be dead when it has been gripped by a predator.
Speaker 3: There could be different explanations, but I think it's generally
Speaker 3: understood that if you pretend to be dead, you can
Speaker 3: wait for the predator to relax its grip or focus
Speaker 3: in order to have a moment to escape other defensive behaviors.
Speaker 3: When cornered, sometimes a horned lizard will inflate its body,
Speaker 3: going to puffer fish mode. This will certainly make it
Speaker 3: look harder to swallow, and maybe actually be harder to swallow. Remember,
Speaker 3: predators can die from eating a horned lizard that is
Speaker 3: too big, so you want the predator to be wondering
Speaker 3: if you are over the.
Speaker 1: Line look more difficult to eat.
Speaker 3: Another strategy is the backshield thing I talked about earlier.
Speaker 3: So you can sometimes flatten your back into a round
Speaker 3: shield and then tilt and orient your back towards the predator.
Speaker 3: This makes you look big, but also makes you look
Speaker 3: difficult to eat. But apparently in other cases they'll do
Speaker 3: the opposite. They'll quickly just turn and face a predator
Speaker 3: head on. Sometimes they hiss like a snake. This could
Speaker 3: be a signal to convey danger and aggression. Sometimes they'll
Speaker 3: kind of vibrate their tails. Now, there's some other predator
Speaker 3: defense strategy stuff that we might come back to in
Speaker 3: part two, but I wanted to get to the blood
Speaker 3: squirting here because this is the main event for me.
Speaker 3: Sometimes when a horned lizard is threatened, it will blast
Speaker 3: a jet of its own blood out of its eyes
Speaker 3: toward the attacker. Now, again, Rob, I think you mentioned
Speaker 3: this earlier. Not all horned lizard species have been observed
Speaker 3: to do this. At the time of Sherbrook's book, he
Speaker 3: did say that most species were known to be blood squirters,
Speaker 3: the majority, where I think maybe there might be more
Speaker 3: different species identified now, so it might not be the
Speaker 3: majority at this point.
Speaker 1: I believe that's the case. But what we can look
Speaker 1: again at that data before we come back with part
Speaker 1: two and clarify if we need to.
Speaker 3: Okay, well, certainly some species do this, Now they don't
Speaker 3: do it every time they're threatened. It seems like a
Speaker 3: fairly specialized behavior. Sherbroke says that among two species, Texas
Speaker 3: horned lizards and regal horned lizards, blood jetting happened during
Speaker 3: four to six percent of human captures, so that's not
Speaker 3: most of the time. You know, it's like one and
Speaker 3: twenty times. It sounds nuts. So it was indeed sometimes
Speaker 3: believed to be a myth, but it is real. So
Speaker 3: Sherbroke writes that you know, if a lizard is about
Speaker 3: to squirt blood out of its eyes, you're going to
Speaker 3: see this. In preparation, the lizard arches its back and
Speaker 3: it closes its eyes, and the lids around the eyes
Speaker 3: become visibly swollen, like you can see that something is
Speaker 3: building up there. And then suddenly a thin stream of
Speaker 3: blood jets out of one or both eyes, and it
Speaker 3: can be shot in either direction, forwards or backwards. This
Speaker 3: blood spray can reach a distance of about six feet,
Speaker 3: and the jet lasts for about one second per blast,
Speaker 3: though the lizard can usually do it again if the
Speaker 3: threat persists, so it's not just like one and done.
Speaker 3: You can blast more than once six feet.
Speaker 1: That is crazy considering the size of these creatures.
Speaker 3: They're a little things, aren't they. Yeah, so does the
Speaker 3: lizard lose a lot of blood from this. Yeah, yeah,
Speaker 3: it does, but it usually recovers if it escapes the situation,
Speaker 3: so it's not like a lethal amount of blood loss,
Speaker 3: but it it does lose a serious amount.
Speaker 1: Better than losing all the blood and the body as well.
Speaker 3: That's right. So research has shown that the horned lizards
Speaker 3: are able to do this via a mechanism that rapidly
Speaker 3: increases blood pressure in chambers within the head. So the
Speaker 3: way it works is that blood flows into the head
Speaker 3: via the arteries, but then the lizards have a set
Speaker 3: of muscle that they can use to squeeze closed the veins,
Speaker 3: leading blood back out of the head. So when they
Speaker 3: squeeze these muscles, blood flows into the head but not out,
Speaker 3: and excess build up of blood flows into the ocular sinuses.
Speaker 3: These are voids within the facial tissue around the eye socket,
Speaker 3: and this manifests externally as bulging eyelids. Eventually, the pressure
Speaker 3: becomes so great that the capillaries in these sinuses burst.
Speaker 3: Blood is rapidly released and escapes through the easiest route
Speaker 3: to the surface through the eye and the tear duct
Speaker 3: and here you get the blood jets. Now there's a
Speaker 3: sentence in Sherbrook's book that I love there's like, oh,
Speaker 3: there's such a story behind this, and no description of
Speaker 3: what this means. Sherbroke writes, quote, humans sampling the blood
Speaker 3: sprayed do not taste anything strongly objectionable.
Speaker 1: That statement raises a number of questions. Who methodology past
Speaker 1: history with the sampling of lizard blood? Yeah? And I
Speaker 1: mean one of the key questions though that arises from
Speaker 1: this is, of course that in a lot of the literature,
Speaker 1: the reason cited for the blood spurning is that there
Speaker 1: is something objectionable about the taste or sensation of this
Speaker 1: creature's blood.
Speaker 3: Well, I think there is, but maybe not perceptible to humans.
Speaker 3: So what is the point of the blood squirting? Well,
Speaker 3: according to Sherbrook, a clue comes down to the relatively
Speaker 3: selective employment of this defensive behavior against only certain predators
Speaker 3: we mentioned it only happens in like four to six
Speaker 3: percent of human captures. The lizard usually does not squirt
Speaker 3: blood out of its eyes at other predators we've mentioned earlier,
Speaker 3: like birds, leopard lizards, snakes. So who do they use
Speaker 3: it against? Dogs? Wild canids such as the coyote and
Speaker 3: the kit fox or Vulpius macro. Any type of dog
Speaker 3: attacks a horned lizard, here come the blood jets. When
Speaker 3: any of the sprayed blood gets into a dog's mouth.
Speaker 3: Sherbroke says that you can usually see the dog showing
Speaker 3: obvious displeasure with the taste, like shaking its head back
Speaker 3: and forth, sometimes chewing or wiping its mouth on grass,
Speaker 3: as if trying to get the taste out of its mouth.
Speaker 1: Oh wow, no, this yeah, this makes a lot of
Speaker 1: sense then. I mean, we've talked before about how dogs
Speaker 1: their sense of smell and therefore their sense of taste
Speaker 1: is just in a realm, so far beyond human levels
Speaker 1: of taste and scent that they it's just a different,
Speaker 1: a different universe.
Speaker 3: Sherbrook writes, quote, clearly there is some chemical component of
Speaker 3: the blood that causes dog family members goosetatory or taste distress.
Speaker 3: The blood never harms them, but it certainly suggests to
Speaker 3: them that a different meal would be more palatable. How
Speaker 3: fortunate for the horned lizard to be able to deliver
Speaker 3: that message before war being severely bitten and tasted. And
Speaker 3: Sherbrooke notes that there are some other lizards, not horned lizards,
Speaker 3: that have occasionally been seen bleeding lightly from the eyes
Speaker 3: under stress, and he speculates that perhaps something like this
Speaker 3: was an early stage in the evolution of this more
Speaker 3: elaborate defensive measure, maybe slight bleeding from the eyes under stress.
Speaker 3: And then horned lizard ancestors have blood that is for
Speaker 3: some reason distasteful to canids. Sometimes that gross blood makes
Speaker 3: a predation attempt stop, and then there's evolutionary incentive to
Speaker 3: bleed more and more of it preemptively to make the
Speaker 3: predation attempt stop earlier and earlier before major injury has occurred,
Speaker 3: until you end up with six foot jets of eyeblood.
Speaker 1: It's like really aggressive free samples in the mall food court. Yes,
Speaker 1: but instead of trying to bring certain customers in, you're
Speaker 1: trying to convince them this food is not for you. Here,
Speaker 1: have a taste.
Speaker 3: But so, why is this blood apparently distasteful to canids
Speaker 3: to dogs?
Speaker 1: So it seems like the main hypothesis, based on what
Speaker 1: I was looking at, is that it comes down to
Speaker 1: what these creatures eat. What the horned lizards eat, they
Speaker 1: eat copious amounts of ants, and those ants contain formic acid.
Speaker 1: So apparently previously researchers thought that the acidity was more
Speaker 1: of a glandular product. But now you know, we understand
Speaker 1: that it's the blood, like that's what's shooting out. There's
Speaker 1: nothing being added to the blood. The blood in and
Speaker 1: of itself is supposed to have this formic acid quality.
Speaker 3: That's right. Sherbrooke makes this point in the book that
Speaker 3: it was once thought that maybe there were blands around
Speaker 3: the eyes adding something to the blood before it gets
Speaker 3: blasted out, but they said no, there's no evidence of that.
Speaker 1: Interesting side note, I've already mentioned another big time ant consumer,
Speaker 1: the giant anteater of Central and South America. That is
Speaker 1: a creature that cannot produce its own stomach acid apparently
Speaker 1: and instead depends on formic acid from its prey. Wow. Yeah,
Speaker 1: I didn't know that. Another interesting fact concerning horned lizards
Speaker 1: here they apparently don't eat fire ants. Fire Ants are,
Speaker 1: of course invasive ants from South America beyond the southern
Speaker 1: limits of the horned lizard's range. They often they're really
Speaker 1: more of a threat to horned lizards because they can
Speaker 1: push out native ant species that the horned lizard depends on,
Speaker 1: while also provoking human inhabitants to deploy anti ant measures
Speaker 1: that you just don't discriminate. So all of this plays
Speaker 1: a role in the habitat loss and decline of various
Speaker 1: horned lizard species.
Speaker 3: Yeah, i'd read that as well. Many horned lizard populations
Speaker 3: throughout the throughout North America have been in decline in
Speaker 3: recent decades. And yeah, fire ants are implicated as part
Speaker 3: of the picture for why that's happening.
Speaker 1: A related question that I didn't even think to ask
Speaker 1: what I just saw come up when I was searching
Speaker 1: around for answers on people ask well, can't we get
Speaker 1: some ant eaters and some armadillos in on these fire ants,
Speaker 1: as these creatures do eat fire ants. And the answer
Speaker 1: there is no, not really, because like an ant eater
Speaker 1: eats a lot of ants, but it has to go
Speaker 1: in like in quick bursts, because it's not immune to
Speaker 1: the bites, and so it's got to get in, like,
Speaker 1: you know, eat a bunch of ants and get out
Speaker 1: of there before it gets too painful. And they're not
Speaker 1: going to finish off a colony like they're not going
Speaker 1: to eat it down to the to the queen. You know,
Speaker 1: they're not gonna eat it down to the last ant.
Speaker 1: It's like a devastating raid, but then they have to
Speaker 1: move on, so it's not going to like wipe out
Speaker 1: populations necessarily. But yes, it seems like the consumption of
Speaker 1: ants is key. And I think we're gonna go ahead
Speaker 1: and close out this episode, but we're gonna be back
Speaker 1: on Thursday. We're gonna get into various other angles concerning
Speaker 1: the horned lizard and also some of the traditions surrounding it,
Speaker 1: including again I teased out some Navajo traditions and they're
Speaker 1: there is one story we're going to come back to
Speaker 1: about the Holy toad who eats ants that give him power.
Speaker 1: Whoa which is correct? The research they're looking at you
Speaker 1: absolutely correct.
Speaker 3: I can't wait.
Speaker 1: All right, Well, we're going to go and close it out,
Speaker 1: but in the meantime, go ahead and write in with
Speaker 1: your observations concerning the horned lizard. You've seen them out
Speaker 1: in the wild, you've studied them right in. We'd love
Speaker 1: to hear from you. We'll come back with part two
Speaker 1: on Thursday. Reminder that that's when our core episodes published
Speaker 1: Tuesdays and Thursdays every week, and the stuff to blow
Speaker 1: your podcast feed where we are primarily a science and
Speaker 1: culture podcast. We do a short form episode on Wednesdays,
Speaker 1: and on Fridays we do Weird House Cinema. That's when
Speaker 1: we set aside most of our serious concerns to just
Speaker 1: talk about a weird film.
Speaker 3: Huge thanks to our excellent audio producer, JJ Posway. If
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