Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2: Hey, welcome to Stuff to Blow Your Mind. My name
Speaker 2: is Robert.
Speaker 3: Lamb and I am Joe McCormick. And today on Stuff
Speaker 3: to Blow Your Mind, we are going to be talking
Speaker 3: about an animal. About the horned lizard or Frenosoma, a
Speaker 3: genus of lizard native to North America, also known as
Speaker 3: horned toads or horny toads. From what I've been reading,
Speaker 3: I think the people in the biological sciences prefer the
Speaker 3: more accurate lizard appellation because they are certainly not toads,
Speaker 3: though there are reasons for calling them toads, mainly that
Speaker 3: they look like toads.
Speaker 2: Now, we're going to probably try and stick to horned lizard.
Speaker 2: I'm probably going to say horned lizard because I like
Speaker 2: using the more antiquated term and it sounds more demonic.
Speaker 2: But we also might say horny toad, horned toad, horn toad,
Speaker 2: and so forth. Throughout the episode.
Speaker 3: Horned Lizard makes me think learned lizard. You know, doesn't
Speaker 3: it suggest a kind of wisdom?
Speaker 2: Yeah? Yeah, sometimes lizards can appear quite wise, so I buy.
Speaker 3: That, And in fact, you might even think about some
Speaker 3: of the species of horned lizards as especially wise or
Speaker 3: discerning among the reptile kind, because they, as we get
Speaker 3: into later in this episode, they have some anti predator
Speaker 3: strategies that really require snap judgment calls about say what
Speaker 3: type of predator you're dealing with?
Speaker 2: That's right, And I don't know if we'll get into
Speaker 2: it in this episode or the next, but among the Navajo,
Speaker 2: among the Dne people, they're sometimes called grandfather so I
Speaker 2: think there is often that vibe of maybe sort of
Speaker 2: 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 have.
Speaker 2: Oh, yeah, it's been an alien summer for me. We've
Speaker 2: been chatting about alien movies and the upcoming alien movie.
Speaker 2: 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 2: That's right, Say yes to Xenomorph and then figure the
Speaker 2: 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 2: We also had a seven part Monster Fact series on
Speaker 2: the various creatures and organisms of the alien universe, with
Speaker 2: part seven publishing this week.
Speaker 3: M 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 in a and
Speaker 3: we've already done a lot of topics along these lines
Speaker 3: in the past, and the idea of the xenomorph's weaponized
Speaker 3: blood took hold. So in the Alien movies, if you
Speaker 3: haven't seen them, the creature in these movies has extremely
Speaker 3: potent acid for blood, which appears to serve as a
Speaker 3: defense strategy. So if you cause injury to one of
Speaker 3: the xenomorphs, you are likely to get some of its
Speaker 3: blood on yourself or on your critical infrastructure, such as
Speaker 3: the inside of your spacecraft hull, and that blood will
Speaker 3: burn through bodies and space ships alike. So, as observed
Speaker 3: by the characters in the first movie, there's real danger
Speaker 3: in injuring the creature. How do you fight it?
Speaker 2: That's right. It's also worth pointing out that there is
Speaker 2: at least some acid fluid as projectile in the xenomorph world.
Speaker 2: The most, I would say, I guess the key example
Speaker 2: would be in nineteen seventy nine's Alien the first film,
Speaker 2: as we see that emergent face hugger seem to use
Speaker 2: acidic secretions to burn through Caine's helmet in order to
Speaker 2: access his face. Now, naturally, given that certain wounds, especially
Speaker 2: lethal wounds to a Xenomorph, could result in a jet
Speaker 2: of acidic blood, we could easily classify that as a
Speaker 2: form of defensive spray. And then in Alien three and
Speaker 2: Alien Resurrection, the third and fourth movies in the franchise,
Speaker 2: we actually see Xenomorphs using an offensive acid spray attack,
Speaker 2: And of course this has also been used to various
Speaker 2: effect in Alien video games. For ranged enemies, as well
Speaker 2: as in alien comic books and so forth. Also worth
Speaker 2: pointing out that, given our current Mortal Kombat discussions on
Speaker 2: Weird House Cinema, the acid spit is one of the
Speaker 2: 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 2: I think it depends. At least in the first game.
Speaker 2: He was in Mortal Kombat too, he would definitely spit.
Speaker 2: I don't. It was like a kind of a sound
Speaker 2: over and over again, and I think it got a
Speaker 2: little more vomity later.
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 2: That's right, because part of the logic here, of course,
Speaker 2: is we tend to think vampire like when we think
Speaker 2: about an organism's blood. Right, It's part of the prize,
Speaker 2: It's part of the predator's claim. So broadly, speaking, it would,
Speaker 2: on the surface anyway, seem illogical to think that a
Speaker 2: predator could be harmed by the 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 2: That's right. They're kind of internet famous for this, a
Speaker 2: lot of clips, a lot of animations and videos. I
Speaker 2: should also add that if you know one thing, you
Speaker 2: should probably know two things. Also, that they're to some
Speaker 2: extent horned up right, because right, tall 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 horn Blizzard's weaponized blood is absolutely
Speaker 3: real and it is the subject of some interesting scientific investigation.
Speaker 2: So this is going to be really fun to get
Speaker 2: into now. When we were doing our pre research, though, Joe,
Speaker 2: you brought up a resource that we've looked to in
Speaker 2: the past, and that's the California herbs dot com website,
Speaker 2: where they have a wonderful I mean, it's not just
Speaker 2: about this, but they have a huge listing of various
Speaker 2: herp appearances in various films, many of which are very
Speaker 2: much in the domain of weird house cinema meaning reptiles, yes, yeah, yeah,
Speaker 2: for herpetologist cinema files. And they have a list there
Speaker 2: that you shared with me of horned lizards in movies,
Speaker 2: and there are a few that I was familiar with,
Speaker 2: you know, because they're pretty popular films. I think what
Speaker 2: Outlaw Josie Wales is on there.
Speaker 3: Yeah, yeah, but the wldye there are apparently a number
Speaker 3: of you know, westerns I guess where there are horned lizards,
Speaker 3: which makes sense because you know, you find a lot
Speaker 3: of these several of these species are very common in
Speaker 3: the American Southwest.
Speaker 2: But also Jo Roowski's Holy Mountain is included there. His
Speaker 2: film from nineteen seventy three that does have a very
Speaker 2: memorable hert scene, though it may contain shots of actual
Speaker 2: herbs exploded with fireworks, so you know, go into that
Speaker 2: one with a certain amount of caution. But it's I mean,
Speaker 2: it's holy mountains, so I'd advise a great deal of
Speaker 2: content consideration before you watch it. Anyway, It's a it's
Speaker 2: kind of a titan of surreal cinema and an important
Speaker 2: film when you're looking at weird psychotronic pictures and you know,
Speaker 2: Mexican cinema certainly cinema of the nineteen seventies.
Speaker 3: But it is not for everyone. Yeah, that's not movie
Speaker 3: Night with the grandparents.
Speaker 2: Yeah, I believe the scene in question. It's been a
Speaker 2: long time since I've seen it, and I have only
Speaker 2: seen it like used to. The only way you could
Speaker 2: watch it would be like a rip of a Japanese
Speaker 2: laser disc. And they're much better sources for it available now.
Speaker 2: But there is an extended scene where the conquest of
Speaker 2: Mexico is recreated with like frogs and toads and lizards
Speaker 2: standing 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 2: So I would say cameo appearance by the horned lizard. Now,
Speaker 2: it's worth noting at the top here that we're not
Speaker 2: dealing with a single species when we're discussing horned lizards,
Speaker 2: but rather an entire genus of North American lizards, and
Speaker 2: that's Phinosoma, including some twenty one species which range as
Speaker 2: far north as parts of Canada and on the southern
Speaker 2: end range all the way through Mexico and into Guatemala.
Speaker 2: And of these again, somewhere around twenty one species, at
Speaker 2: least eight species squirt blood from the eye region. So
Speaker 2: just an example of range here, there's the greater short
Speaker 2: horned lizard or hernandez is short horned lizard, and it
Speaker 2: can be found as far north as southern Saskatchewan and
Speaker 2: Alberta and south into the Texas Panhandle in central Mexico.
Speaker 2: 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: western part of North America, from down to southern Mexico,
Speaker 3: all the way up to the southern part of Canada.
Speaker 3: And you can look up maps that show you sort
Speaker 3: of different estimated ranges of the different species. But yeah,
Speaker 3: you'll find them all throughout the arid and semi arid
Speaker 3: regions of the North American West. Here, I think it
Speaker 3: would be a good place to introduce one of my
Speaker 3: major sources for this episode, which is a book called
Speaker 3: Introduction 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 to sort of turn their
Speaker 3: backs into a shield. They tend to for lizards have
Speaker 3: 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 phrenos
Speaker 3: as toad and soma, of course means body, toad body,
Speaker 3: total toad body to add to the toad comparisons to
Speaker 3: make them even more of a toad body. You can
Speaker 3: observe how they eat. Now. The different species of horned
Speaker 3: lizards have some different different diets. Some are more 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 digested and essentially disables it from biting or
Speaker 3: stinging the lizard from the inside until it is well
Speaker 3: dead and able to be digested. And these lizards have
Speaker 3: to eat a lot of these ants because ants are
Speaker 3: not super nutritious like they've got There's not a lot
Speaker 3: of meat on that bone. It's mostly bone.
Speaker 2: That's right. Like For instance, one of the other big
Speaker 2: ant eaters out there is of course the mammalian ant eater,
Speaker 2: and they are known to eat tons of ants and termites,
Speaker 2: seen estimates of like thirty thousand ants and termites a day.
Speaker 2: But even that is still a low calorie diet, and
Speaker 2: it's one of the reasons that we think that ant
Speaker 2: eaters have one of the lowest mammalian body temperatures. But
Speaker 2: in terms of the the what we're dealing with here,
Speaker 2: the horned lizards consumption of ants. I found an interesting
Speaker 2: article that answers the question, well, how do they eat
Speaker 2: them safely? This was from two thousand and eight published
Speaker 2: in the journal jazz A by Sherbrooke and Schwink. And
Speaker 2: the answer is in the title Horned lizards incapacitate dangerous
Speaker 2: ant prey with mucus. And we've already touched on like
Speaker 2: the main aspect of this, but they provide one more
Speaker 2: little detail that I really like. They're write quote. We
Speaker 2: show that they're derived feeding kind of mattics are associated
Speaker 2: with unique mucus secreting phar angel papilia that apparently serve
Speaker 2: to immobilize and incapacitate dangerous ants as they are swallowed
Speaker 2: by compacting them and binding them in mucus trans And
Speaker 2: then they later add the detail. Ants extracted from fresh
Speaker 2: killed horned lizard's stomachs are curled ventrally into balls and
Speaker 2: bound in mucus.
Speaker 3: Take an ant as you as you're swallowing it, coat
Speaker 3: it with slime, and wadd it up into a ball
Speaker 3: so that you can digest it without it getting into
Speaker 3: trouble inside your digestive tract. That's right, roll them up,
Speaker 3: all right, So that is horned lizards as predators. But
Speaker 3: I wanted to focus for the majority of today's episode
Speaker 3: on horned lizards as prey because it is, of course
Speaker 3: in their role as prey and in their anti predator
Speaker 3: defense strategies that we see the jets of blood emerge
Speaker 3: from the eyes. So here I want to go back
Speaker 3: to that book I mentioned by Wade Sherbrook. He has
Speaker 3: an excellent section in this book called the Enemies and Defense,
Speaker 3: which sort of covers a nearly comprehensive list of different
Speaker 3: sort of predator prey relationships between horned lizard species and
Speaker 3: the predators that target them, and the strategies they have
Speaker 3: for resisting these predators. So, as we alluded to earlier,
Speaker 3: horned lizards are of course covered in spikes and scales.
Speaker 3: This is a pretty sophisticated armor defense. If you've never
Speaker 3: seen what a horned lizard looks like, by the way,
Speaker 3: you should look one up. I mean, first of all,
Speaker 3: they are beautiful, but this will give you a better
Speaker 3: idea of what we're talking about. As we continually reference
Speaker 3: the armor moving on, they tend to have spikes and
Speaker 3: scales along different parts of their bodies, such as sort
Speaker 3: of spiky flank protrusions running down the lateral sides of
Speaker 3: the body, but then also sometimes some kind of bumpy
Speaker 3: or tough coverings on the back, and then especially bony
Speaker 3: spike protrusions around the crown of the head. So some
Speaker 3: of the spiky looking things, usually the smaller ones, are
Speaker 3: just more modified scales, but the spikes around the head
Speaker 3: are actually like hard, sharp bony spikes now covered in
Speaker 3: spikes and scales as they are. You might not think
Speaker 3: that a horned lizard would look very appetizing, but you
Speaker 3: know out here in the arid and semi arid regions
Speaker 3: of the American West, many predators will take whatever they
Speaker 3: can get, and so horned lizards are indeed a prey
Speaker 3: animal to many species of predators. Juveniles are the most
Speaker 3: vulnerable to predation. They're smaller and they have less developed armor,
Speaker 3: so many are eaten between the time they hatch from
Speaker 3: their eggs and the first hibernation. But Sherbrooke in this
Speaker 3: chapter gets into a list of different predators, and the
Speaker 3: first one I want to look at is his section
Speaker 3: on the long nosed leopard lizard or the Gambelia whizly zennii.
Speaker 3: These are worth looking up a picture of as well,
Speaker 3: because while they're not very interesting in terms of shape,
Speaker 3: they're just sort of like larger looking predatory lizards. They
Speaker 3: do have a truly leopard looking coloration pattern.
Speaker 2: 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 2: Yeah, yeah, you can't put it in reverse.
Speaker 3: Sherbrooke says in the book about defensive strategies that when
Speaker 3: attacked by a leopard lizard a horned lizard, and again,
Speaker 3: defensive strategies vary somewhat by species, so we'll be speaking
Speaker 3: in some generalities here, but the horned lizard will often
Speaker 3: try to defend itself by flattening out its back into
Speaker 3: a wide shield shape so it wants to look as
Speaker 3: wide as possible, and then tilting and orienting its armored
Speaker 3: shield back toward the predator. And again, Adults with well
Speaker 3: developed armor are much less vulnerable to leopard lizards. Now,
Speaker 3: the next category is birds. A number of different birds
Speaker 3: prey on horned lizards. Sherbert mentions hawks such as the
Speaker 3: red shouldered hawk or Boeo lineatus, but also smaller birds
Speaker 3: like 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 their,
Speaker 3: you know, their way of making a living, But I
Speaker 3: cannot imagine eating something this spiky.
Speaker 2: And it's like a like a like a wheat then,
Speaker 2: except even worse.
Speaker 3: Right, Yeah, Oh, it's like you know, you ever think
Speaker 3: when you're like eating a tortilla chip and you don't
Speaker 3: chew it upright and you get a shard caught in
Speaker 3: your throat. Yep, okay. Another bird that preys on these
Speaker 3: animals is the greater road runner or Geocossics californian us.
Speaker 3: The greater roadrunner has an interesting strategy where it grabs
Speaker 3: the horned lizard by a leg or by the tail
Speaker 3: with its beak, and then it whips them up in
Speaker 3: the air and slams them back down against the ground repeatedly,
Speaker 3: so it is beating the lizard against the earth, using
Speaker 3: centrifugal force to smash it dead. Basically, it bashes it
Speaker 3: and bashes it until it is dead and busted up,
Speaker 3: and this allows the roadrunner to take its time orienting
Speaker 3: the lizard so it can be swallowed whole head first.
Speaker 3: Rabbie attached to a picture for you of the Greater
Speaker 3: Roadrunner trying to get this whole lizard into its mouth
Speaker 3: head first that I don't know how this is going
Speaker 3: to happen. This is just a photo from the book.
Speaker 3: It's not animated, but I believe in you.
Speaker 2: Yeah, yeah, yeah, I mean, roadrunners are such interesting, weird
Speaker 2: creatures in their own ride. I don't feel like the
Speaker 2: cartoons properly prepared as for the reality only seen. I've
Speaker 2: only seen them in the wild, I think one or
Speaker 2: two times while out in the Arizona. But it's like
Speaker 2: it's like seeing like the ghost of a dinosaur run by.
Speaker 2: 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 2: Clever girl.
Speaker 3: Yeah yeah, okay. So another bird predator, Chihuahuan ravens or
Speaker 3: corvas crypto. Lucus 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: innerds to the hatchlings, so only guts for the children,
Speaker 3: and then the carcass with the hard parts is discarded.
Speaker 2: All right, Well that's not surprising. I'll leave it to
Speaker 2: the ravens to intelligently dissect before eating. To the end.
Speaker 3: They're like a tourist at a beach restaurant picking the
Speaker 3: meat out of a crab. They're getting all the juicy
Speaker 3: bits and not swallowing the hard parts. Of course, snakes
Speaker 3: are a major predator of these lizards. Various species of
Speaker 3: snakes prey on them, killing them either with venom or
Speaker 3: with constriction, and then in all cases, swallowing them whole. Snakes,
Speaker 3: like birds, do incur some risk by attempting to swallow
Speaker 3: a horned lizard. Sometimes the horns rip them open from
Speaker 3: the inside, and a crucial factor seems to be just
Speaker 3: the relative sizes of the snake in the lizard. The
Speaker 3: snake it's hungry, but it can't get too greedy. It
Speaker 3: has to know its limits. And so I guess there
Speaker 3: are cases where a snake might be sort of driven
Speaker 3: near starvation and it's pushing the boundaries of like, is
Speaker 3: this thing so big it's gonna kill me to eat it?
Speaker 3: I'm gonna roll the dice. Now, that's not all the
Speaker 3: potential predators of horned lizards, but I'm gonna come back
Speaker 3: to one more major category in a minute when we
Speaker 3: get to the blood squirting. So there's another interesting framework
Speaker 3: that Sherbrook introduces in this chapter where he's talking about
Speaker 3: the different levels of defense that a prey animal can
Speaker 3: deploy when trying to survive against predators. And the three
Speaker 3: layers of defense he talks about are first of all,
Speaker 3: avoid being seen, second, avoid being caught, and third be
Speaker 3: difficult to eat or appear dangerous to the predator. And
Speaker 3: you could sort of paraphrase these as one hide, two,
Speaker 3: run in three fight. Horned lizards are not very good
Speaker 3: at number two. They're not very good at running away.
Speaker 3: There are some exceptions, such as when facing off against
Speaker 3: certain snakes venomous snakes like the diamondback rattle snake. Sometimes
Speaker 3: in facing off against one of those, the lizard will
Speaker 3: just run away, But in most cases it's not going
Speaker 3: to be great at trying to outrun predators, and they've
Speaker 3: got kind of short limbs and awkward movements. So mostly
Speaker 3: horned lizards excel at number one and number three avoiding
Speaker 3: being seen in the first place. And then if they
Speaker 3: really if they're cornered and they're caught and they can't
Speaker 3: hide anymore, they resist being eaten somehow by a combination
Speaker 3: of morphological and behavioral defenses. So we'll look at number
Speaker 3: one first, the hiding part. Horned lizards are masters of camouflage,
Speaker 3: and Sherbrooke has an interesting side note about how we
Speaker 3: often don't appreciate how effective a wild animal's camouflage actually
Speaker 3: is because most people, you know, if you're not like
Speaker 3: living out in the wilderness, most of the time you're
Speaker 3: going to see any of these wild animals, it's in
Speaker 3: some form of media that is designed to help you
Speaker 3: see the animals, such as like a picture in a
Speaker 3: book or foot in a documentary where the whole point
Speaker 3: is that you're supposed to be able to see it,
Speaker 3: And so this kind of we kind of underappreciate how
Speaker 3: effective natural camouflage strategies are because if we were just
Speaker 3: walking around in the environment, we likely might go right
Speaker 3: by animals of this type and never see them, so
Speaker 3: we wouldn't even know that we'd miss them.
Speaker 2: That's a great point.
Speaker 3: Yeah, And so horned lizards are very good at hiding.
Speaker 3: They hide themselves with a couple of strategies. They hide
Speaker 3: by disrupting predator search routines for both shape and color,
Speaker 3: so their coloration tends to mimic the patterns of gravelly,
Speaker 3: sandy or grassy grounds where they live, and the pigment
Speaker 3: in their skin tends to match the color of the
Speaker 3: local soil or whatever the background is. So, for example,
Speaker 3: horned lizards that live in areas with redder soil will
Speaker 3: be redder in color and so forth. Also in the
Speaker 3: domain of color, they have patterns of what is called
Speaker 3: disruptive color. This is found in many animals where varied
Speaker 3: color patterns make it harder to pick out the outline
Speaker 3: of an object against the background. This is also one
Speaker 3: of the main principles behind human tactical camouflage. Some of
Speaker 3: their hiding strategies are more obvious, like in some cases,
Speaker 3: if there is a predator around, they might increase their
Speaker 3: hiddenness by ducking underneath something so they can run under
Speaker 3: a shrub or a rock or some of their groundcover.
Speaker 3: But another thing they do often is if a predator
Speaker 3: is nearby, they can flatten their bodies against the ground.
Speaker 3: And this especially helps protect against, say, the visual detection
Speaker 3: by birds, because this flattening prevents them from casting a shadow,
Speaker 3: which 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
Speaker 3: know as ectotherms, they need to spend a lot of
Speaker 3: time absorbing sun anyway. Because their body temperature is dependent
Speaker 3: on the surrounding environment, they don't generate their own body
Speaker 3: heat 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 2: Or like a metal gear game where you just immediately
Speaker 2: put a box over your body and then they're looking
Speaker 2: right at you and maybe they won't see it.
Speaker 3: Huh.
Speaker 2: But you know, I have to say I only have
Speaker 2: human eyes. I don't have the eyes of an eagle,
Speaker 2: and they're not even great human eyes. But you know,
Speaker 2: there have been times where I've been watching an animal
Speaker 2: in the wild that is really good at its camouflage,
Speaker 2: and you know, either it will be the situation of
Speaker 2: looking right at it and not seeing it until there
Speaker 2: is movement, or the reverse kind of looking at it
Speaker 2: in movement and then the second it stops, I cannot
Speaker 2: see it anymore. I know it is there, but I
Speaker 2: cannot actually see it. It's just based on the memory
Speaker 2: 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. Your invisibility camouflage
Speaker 3: stealth mode has failed. You're a horned lizard and you're
Speaker 3: cornered by a predator that definitely knows you're here. Here,
Speaker 3: we get to the active defense strategies where you try
Speaker 3: to make yourself look difficult to eat or dangerous to
Speaker 3: the predator. Now, the range of behaviors described in Sherbrook's
Speaker 3: book here are surprisingly diverse. I wouldn't have expected this
Speaker 3: many different things to be on the record, but Sherbrook
Speaker 3: lists a number of them, just in respond to the
Speaker 3: presence of humans. To read from a paragraph here quote
Speaker 3: in an almost comic antic one horned lizard raised itself
Speaker 3: high on all four legs, lowered its head, and in
Speaker 3: a series of hops, approached its tormentor like a charging bull.
Speaker 3: On another occasion, a horned lizard charged and bit a
Speaker 3: person's boot. Normally they do not bite when captured by hand,
Speaker 3: but some struggle an attempt to thrust their horns into
Speaker 3: the flesh of their captor. Now that's kind of interesting, though.
Speaker 3: There are also reports that a good number of these lizards,
Speaker 3: if picked up and handled and sometimes rubbed or stroked,
Speaker 3: they will become immobile. And this could be some kind
Speaker 3: of death feigning strategy as seen in some prey animals.
Speaker 3: You might wonder, like, why would it be advantageous for
Speaker 3: a prey animal to pretend to be dead when it
Speaker 3: has been gripped by a predator. There could be different explanations,
Speaker 3: but I think it's generally understood that if you pretend
Speaker 3: to be dead, you can wait for the predator to
Speaker 3: relax its grip focus in order to have a moment
Speaker 3: to escape other defensive behaviors. When cornered, sometimes a horned
Speaker 3: lizard will inflate its body, going to puffer fish mode.
Speaker 3: This will certainly make it look harder to swallow, and
Speaker 3: maybe actually be harder to swallow. Remember, predators can die
Speaker 3: from eating a horned lizard that is too big, so
Speaker 3: you want the predator to be wondering if you are over.
Speaker 2: The 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 want 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 2: I believe that's the case, but we can look again
Speaker 2: at that data before we come back with part two
Speaker 2: 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. Sherbrook 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 in
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: Sherbroch 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 2: 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, 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 2: 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 muscles 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 manifest tests externally as bulging eyelids. Eventually, the
Speaker 3: pressure 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 2: That statement raises a number of questions, who methodology past
Speaker 2: history with the sampling of lizard blood? Yeah, and I
Speaker 2: mean one of the key questions though that arises from this,
Speaker 2: is of course that in a lot of the literature
Speaker 2: the reason cited for the blood spurning is that there
Speaker 2: is something objectionable about the taste or sensation of this
Speaker 2: 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 cannids such as the coyote and
Speaker 3: the kit fox or Vulpius Macrotis 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: Sherbrooke 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 2: Oh wow, no, this yeah, this makes a lot of
Speaker 2: sense then. I mean, we've talked before about how dogs
Speaker 2: their sense of smell and therefore their sense of taste
Speaker 2: is just in a realm, so far beyond human levels
Speaker 2: of taste and scent that it's just a different, a
Speaker 2: different universe.
Speaker 3: Sherbroke 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 being severely bitten and tasted. And Sherberke
Speaker 3: 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 2: It's like really aggressive free samples in the mall food court. Yes,
Speaker 2: but instead of trying to bring certain customers in, you're
Speaker 2: trying to convince them this food is not for you. Here,
Speaker 2: have a taste.
Speaker 3: But so why is this blood apparently distasteful to canids
Speaker 3: to dogs?
Speaker 2: So it seems like the main hypothesis, based on what
Speaker 2: I was looking at, is that it comes down to
Speaker 2: what these creatures eat. What the horned lizards eat, they
Speaker 2: eat copious amounts of ants, and those ants contain formic acid.
Speaker 2: So apparently previously researchers thought that the acidity was more
Speaker 2: of a glandular product, but now we understand that it's
Speaker 2: the blood, Like that's what's shooting out. There's nothing being
Speaker 2: added to the blood. The blood in and of itself
Speaker 2: 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 glands 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 2: Interesting side note, I've already mentioned another big time ant consumer,
Speaker 2: the giant anteater of Central and South America. That is
Speaker 2: a creature that cannot produce its own stomach acid apparently,
Speaker 2: and instead depends on formic acid from its prey.
Speaker 3: Wow.
Speaker 2: Yeah, I didn't know that. Another interesting fact concerning horned
Speaker 2: lizards here, they apparently don't eat fire ants. Fire Ants are,
Speaker 2: of course invasive ants from South America beyond the southern
Speaker 2: limits of the horned lizard's range. They often they're really
Speaker 2: more of a threat to horned lizards because they can
Speaker 2: push out native ant species that the horned lizard depends on,
Speaker 2: while also provoking human inhabitants to deploy anti ant measures
Speaker 2: that you know, just don't discriminate. So all of this
Speaker 2: plays a role in the habitat loss and decline of
Speaker 2: various 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 2: A related question that I didn't even think to ask
Speaker 2: what I just saw come up when I was searching
Speaker 2: around for answers on this, people ask, well, can't we
Speaker 2: get some ant eaters and some armadillos in on these
Speaker 2: fire ants, as these creatures do eat fire ants. And
Speaker 2: the answer there is no, not really, because like an
Speaker 2: ant eater eats a lot of ants, but it has
Speaker 2: to go in like in quick bursts, because it's not
Speaker 2: immune to the bites, and so it's got to get in, like,
Speaker 2: you know, eat a bunch of ants and get out
Speaker 2: of there before it gets too painful. And they're not
Speaker 2: going to finish off a colony, like they're not going
Speaker 2: to eat it down to the queen, you know, they're
Speaker 2: not going to eat it down to the last ant.
Speaker 2: It's like a devastating raid. But then they have to
Speaker 2: move on, so it's not going to like wipe out
Speaker 2: populations necessarily. M But yes, it seems like the consumption
Speaker 2: of ants is key, and I think we're gonna go
Speaker 2: ahead and close out this episode, but we're gonna be
Speaker 2: back on Thursday. We're gonna get into various other angles
Speaker 2: concerning the horned lizard and also some of the traditions
Speaker 2: surrounding it, including again I teased out some Navajo traditions,
Speaker 2: and there there is one story we're going to come
Speaker 2: back to about the Holy Toad who eats ants that
Speaker 2: give him power. Whoa which is correct? The research they're
Speaker 2: looking at here absolutely correct.
Speaker 3: I can't wait.
Speaker 2: All right, Well, we're going to go and close it out,
Speaker 2: but in the meantime, go ahead and write in with
Speaker 2: your observations concerning the horned lizard. You've seen them out
Speaker 2: in the wild, you've studied them, write in. We'd love
Speaker 2: to hear from you. We'll come back with part two
Speaker 2: on Thursday. A reminder that that's when our core episodes
Speaker 2: published Tuesdays and Thursdays every week and the Stuff to
Speaker 2: Blow Your Mind podcast feed, where we are primarily a
Speaker 2: science and culture podcast. We do a short form episode
Speaker 2: on Wednesdays, and on Fridays we do Weird House Cinema.
Speaker 2: That's when we set aside most of our serious concerns
Speaker 2: to just talk about a weird film.
Speaker 3: Huge thanks to our excellent audio producer jj Posway. If
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