21: Coquí & Bombardier Beetle
Ellen: Hey Friends, this is Ellen Weatherford.
Christian: And Christian Weatherford.
Ellen: And we are here with Just the Zoo of Us, an animal review podcast where we take your favorite species of animals and rate them out of 10 in the categories of effectiveness, ingenuity, and of course aesthetics.
Christian: We are not zoological experts. We do a lot of research and try our best to make sure we're presenting information from trustworthy resources, but if we get it wrong, let us know.
Ellen: Yeah, we will do our best to make it right.
Christian: I will travel back in time, assassinate myself, and take my own place to give better information.
Ellen: But then they wouldn't have anything to correct.
Christian: Time paradox. [X-files theme]
Ellen: Welcome to the Area 51 special. Just kidding. We're not really doing that, because we're recording this on the day of the Area 51 raid, but this will come out next week. But we do have a huge, probably our biggest ever update and that is that we have a ceiling fan in our office now.
Christian: I was like, "Uh oh, what did I forget?"
Ellen: Christian put up a ceiling fan in our office and that's the room that we record in and it's making it a lot more pleasant to record in here.
Christian: It sure is. It's normally sweltering.
Ellen: So hopefully that recording in pleasant conditions will just allow us to bring even better content.
Christian: Agreed.
Ellen: So, last week Christian went first with the jaguar. So this week it's my turn.
Christian: What do you got for us this week, honey?
Ellen: This week I am going to be talking about a beloved cultural icon: the coquí.
Christian: Ah!
Ellen: Yeah, the scientific name is Eleutherodactylus coqui.
Christian: I like that.
Ellen: Yes. It's a beautiful name. The species was requested by our friend Edwin Rivera. Thank you, Edwin. Edwin requested this saying that this is a species that is near and dear to his heart because the coquí is the cultural icon of Puerto Rico.
Christian: That's right. We learned a little bit about this in the JoCo Cruise earlier this year when we went to San Juan.
Ellen: We did. We got to stop by in San Juan for a little bit. Now we didn't hear the coquís and we didn't really get any exposure while we were there. Still...
Christian: Saw lots of references to it.
Ellen: Yes, lots and lots. This is a very popular animal in Puerto Rico. Just before I launch into it, I'm getting my information from the US Department of Agriculture's Forest Service, the Animal Diversity Web- we love them, we're always up in their business- and, this is interesting, the Journal of the Acoustic Society of America.
Christian: Okay. Interesting.
Ellen: Yeah. I'm really glad that we're talking about this animal because most of the animals that we talk about, I think we talk about their visuals a lot, which doesn't always translate super well to an audio medium. This animal is made to be talked about over an audio medium.
Christian: Excellent.
Ellen: Yes, this is perfect. So just to introduce you to my new friend, the coquí, their adult size is only up to five and a half centimeters, or a little over two inches, and that is like as big as they get.
Christian: Alright.
Ellen: So they're typically gonna be around an inch long. It's a little dude! It's a small frog. I didn't mention that they're frogs. They're frogs! They're tiny, tiny frogs. They are native to Puerto Rico where they can be found pretty much throughout the entire island, pretty much all over the place. Um, most notably the famous rainforest in Puerto Rico, El Yunque National Forest.
Christian: Oh yeah. Was that the one near San Juan?
Ellen: It's near San Juan, yeah. It was close to where we were, but not close enough for us to reasonably go there cause we had to be back.
Christian: Sure.
Ellen: But um, yeah. El Yunque rainforest. Now their taxonomic family is Eleutherodactylidae. These are rain frogs. That name comes from Greek and it translates to "free-toed." Not T-O-A-D, it's not a free toad. You can't go to the store and ask for a free toad. By "free-toed," they mean that their feet are not webbed.
Christian: Oh! Okay.
Ellen: Yep. They don't have any webbing between their toes, which basically just means that they're not necessarily adapted to be like aquatic. Their feet aren't adapted to swimming. This is more of a land-dwelling frog. Now, this family of frogs is known for its practice of direct development. So what this means is that the babies emerge from the eggs not as tadpoles, but as froglets. They develop through the tadpole phase inside the egg, and by the time they hatch from the egg, they have already grown legs.
Christian: I guess that makes sense if they're not in bodies of water usually.
Ellen: Right, right. Now there are over 700 species of frogs in this family, and 18 of them are different species of coquí,
Christian: Huh.
Ellen: Yup. So the one that I picked is just the common coquí. This is the one that you're going to find all over the island. It is the one that there seems to be the most information about, so that's why I picked it. There are a few other different species including some that are believed to be extinct. It's really interesting because they seem to have like, just developed on the island of Puerto Rico and that's it. That's pretty cool. Yeah, that is just your little introduction to the coquí. So I'm going to get into my ratings for this animal. So if you're joining us for the first time, what we do is we rate our animals in three categories, the first of which is effectiveness, and we define effectiveness as how good is this animal at doing the things that it needs to do. So these are physical adaptations that let the animal do a good job. So I'm giving the coquí a 7 out of 10 for effectiveness.
Christian: It's pretty good.
Ellen: It's pretty good. It's decent. So first of all, they have pretty good camouflage. They're just kind of a standard brown color, but they have markings that are, like brown-adjacent. So they could be tan or like light yellow or a darker brown. They just, they blend in with the wood of the trees that they're in or the leaves on the ground, stuff like that. They blend in very easily with foliage, so they're pretty good at staying hidden, which is good because they are ambush predators. So they do like, eat insects around them and stuff. They'll pretty much eat anything that can fit in their tiny, tiny little mouth, but they're ambush predators so they'll lay and wait until their prey is close enough for them to jump out at them and get. Their lack of a tadpole stage means that they don't actually need standing water. This is really good for living in a rainforest environment where there might not always be standing water available, like during the dry seasons or something. They also do absorb moisture through their skin like other frogs do, so they're really well adapted for living where they live in the rain forest, they don't necessarily need standing water to get by because they don't have to necessarily drink water, like through their mouth. They can absorb it through their skin.
Christian: Makes sense.
Ellen: Yeah. So kind of the most defining characteristic of the coquí is their voice. For being only about an inch long, they have an extremely loud voice.
Christian: Oh boy.
Ellen: Yeah. The cry of the coquí can be up to 90 decibels, which is about as loud as a lawn mower. This is kind of what they're most known for. I actually put more information about this in the ingenuity section.
Christian: Okay.
Ellen: Which I'm going into right now.
Christian: Oh, well here we are!
Ellen: It's time. So for ingenuity, we define this as behavioral adaptations that an animal has that let it do clever things. So maybe it has a problem that it needs to solve on a daily basis, or maybe there's an obstacle in its way that it needs to kind of figure out. These are smart things that an animal does. I give the coquí an 8 out of 10.
Christian: Really!
Ellen: Which is higher than I expected to give a frog.
Christian: Sure.
Ellen: This is a clever frog.
Christian: Oh boy.
Ellen: Yes. So, the coquí gets their name from their iconic call that they make. So, their name is actually onomatopoetic.
Christian: Like a Pokémon!
Ellen: Which is, by the way, onomatopoetic is my favorite word in the English language. It's so- yes! It's exactly like a Pokémon! They say their name. They do, and this is the only animal I can think of like this, but they do say their name. So the call, first of all, it's only used by males. Females do not make the sound. Females will make like, some small sounds but not very many. So when you hear a coquí, it is a male making this sound.
Christian: I bet I can guess what the purpose is, then.
Ellen: Yes you can, but hold on. It gets more interesting than that. So, they produce this call during the evening and throughout the night to communicate with other coquís. It's not necessarily like to, I don't know, ward off predators or anything. So what is distinct about the call of the coquí is that it is divided into two distinct parts, like how the name goes "coquí," the first part of the call is a low-pitched "co-" and then the second part is a high pitched "-KEE." So their cry sounds like "co-KEE."
Audio: [recording of a rain forest full of coquí singing]
Ellen: It's so precious. It's really cute. So the first part is much, much lower and the second part is much, much higher.
Christian: Sure.
Ellen: There is a very particular reason for this.
Christian: Ooh...
Ellen: Yes. So each part of their cry sounds the way it does because they're intended for different audiences. Male and female coquís have auditory neurons that are distributed differently from each other. Their brains are literally wired differently. Their inner ears are tuned differently, meaning that males and females cannot hear the same pitches. Females can hear much, much, much higher pitches than males can.
Christian: Huh.
Ellen: Yes. So, this is actually a really cool example of sexual dimorphism in the auditory system.
Christian: Yeah, for sure.
Ellen: Where they're actually processing their environment differently, based on male and females.
Christian: Huh.
Ellen: Yes. This is wild. This is so cool. What is even more interesting about that is that, so the "co-" part of the cry is directed at other males to warn them, like, "hey, I'm here, I'm a male. You need to know where I am so that you know to not be in my zone." Right, they're trying to like keep other males away from them. So that's what the "co-" part of the sound is. And the "-KEE" part of the sound is directed at females to let them know, "hey, I'm over here. It's me, a male. Come, come uh, hang out with me. Yeah, come get some." Basically. So in the absence of other males, they will skip the "co" and just do the "kee." And in the absence of females, they'll skip the "kee" and just do the "co."
Christian: Interesting!
Ellen: So they can like, kinda tell, they're like, "okay, it doesn't seem like there's any females around here, so I don't necessarily need to broadcast to them. I'll just do the 'co' part. So I'm just talking to like- hey fellas. Hey fellas." When they're done with that, they're like, "all right, now ladies."
Christian: Like that song.
Ellen: Yes. But so yeah, so they're talking specifically to whatever sex of frog is closest to them, and like they can tell who's nearby and they change their call based on who they're trying to talk to.
Christian: I wonder if that's based on what they can see, or what they've heard. Like maybe they can hear other males.
Ellen: Right. Like they can hear if there's other males near them. Right?
Christian: Yeah.
Ellen: So if they don't hear any other males nearby, they're like, okay, maybe I don't necessarily need to call out to the males.
Christian: Okay.
Ellen: Yeah. So I thought that was really fascinating. I put this in ingenuity because I figured like even though this isn't necessarily like a conscious decision that the frog is making, this just shows that they have adapted to the neurological differences between males and females and have this habitual behavior that's like, tailored to the whole auditory processing system of the different frogs.
Christian: Yeah, that's crazy.
Ellen: Yes! That is so cool! That's such high-level stuff. So, the next thing I want to talk about for their ingenuity is the coquís like to hang out in different parts of the trees based on what kind of time it is. So first of all, like the older ones, the older adult ones, you'll find them up higher in the trees than the juveniles who like to stay kind of closer to the ground. The coquí likes to hang out at the tops of the trees at night when it's nice and cool and it's kind of humid, and there's a lot of kind of like bugs flying around up in the tops of the trees, so they like to hang out up there. But then when the sun starts to come out, things start to dry up. It starts to get a little hotter, they will be like, hmm, I need to kind of get lower to the ground cause it's a little too hot up here. But, if they were to just kinda hop back down the tree, like try to climb back down the tree, they'd be really, really vulnerable to tarantulas, lizards, predators like that, that are coming out around that time of morning. So, they just jump out of the tree.
Christian: Oh.
Ellen: And fall to the ground. They're speedrunning getting back down to the ground.
Christian: Can I back it up a real- just real quick?
Ellen: Yeah, what?
Christian: Does Puerto Rico have tarantulas?
Ellen: Yes.
Christian: I did not know that.
Ellen: Yeah.
Christian: Huh...
Ellen: Big ol' spidders. They got 'em. Yeah. Which will eat the frogs cause the frogs are very small.
Christian: Okay.
Ellen: But so they will just jump out of the tree and fall to the ground and...
Christian: All that stuff? Nah!
Ellen: Yeah. So they just kind of daredevil jump right out of the tree and fall on the ground. This has led to people describing El Yunque Forest as raining frogs.
Christian: Ohhh, that's very good.
Ellen: Mmhmm. So what's funny is that you hear that and you think, "okay, they probably just mean either there's a lot of frogs there or maybe it rains really, really heavily." Like how you and I would say like, "it's raining cats and dogs" or something?
Christian: Yeah.
Ellen: Which I say we would say that, but I don't think I've ever said that in my life. I don't feel like it's as common as a phrase.
Christian: Yeah.
Ellen: But so how you and I might say it's raining cats and dogs., maybe this is like the Puerto Rican version, like it's raining frogs?
Christian: I guess.
Ellen: But no, it literally rains frogs. The frogs literally fall out of the sky.
Christian: I wonder if there's a particular time when it happens.
Ellen: Yeah. It's like early in the morning.
Christian: But like, at the minute, like could you set your clock to it?
Ellen: I really doubt it! I don't think it's like, "oh well it's 8:16" and then just every single- like hundreds and hundreds of frogs all at once.
Christian: Like when you go outside at a particular time, you have to remember to bring an umbrella.
Ellen: I don't think it's like that, but that would be really funny if it was. I'd really like that. So yeah, I thought that was pretty clever of them to figure out like, hmm, I can just use gravity to get down back to where I need to go without getting gobbled up.
Christian: I'm guessing it's such that they don't weigh enough to hurt themselves from that fall.
Ellen: Right. Yeah. They're just too small. They don't really take fall damage.
Christian: Maaan. Lucky.
Ellen: I mean, like you don't worry about something like a spider falling. It's like he's going to be fine. He's too little. It's just a little frog. He's fine. So yeah, they jump out of trees. I thought that was pretty smart of them to do that, to keep away from predators.
Christian: I agree.
Ellen: The last thing I wanted to talk about for their ingenuity, this is not a behavior that is specific to this species of frog, but it's still something that I found kind of endearing: since they do hatch into froglets rather than tadpoles, the coquí lays their eggs on plants rather than water. So this means that the eggs and the froglets are a little bit more vulnerable to different threats, like just environmental threats, but also little bit more vulnerable to being found by predators or messed with in some way. So male coquís will guard the eggs and- yeah, so the female like just lays the eggs and leaves, but the male actually hangs around the eggs and guards them to make sure that nobody comes along and gobbles them up.
Christian: That's a nice little trade off there.
Ellen: Yeah, they'll even stick around like for a few days after the froglets hatch to like! Make sure they kind of make it. Yeah. So they're actually good dads. That wasn't something I was expecting to find about a frog, you know? And I feel like when I think about frog parenting, I imagine just like, they lay their eggs and leave, which is what a lot of water-dwelling frogs will do. Like when they lay their eggs in the water, they'll just put them there and peace out, but the coquí will kind of hang around and make sure that their babies are okay. I thought that was really sweet.
Christian: Cute.
Ellen: So that wraps up my 8 out of 10 for ingenuity. This is a surprisingly clever little frog. I like it. I was kinda surprised to find all that stuff out, but...
Christian: Yeah, I imagine.
Ellen: I was very pleased by it. This brings us to my final category for the coquí. This is the aesthetics. For aesthetics, I gave it a 7 out of 10 as well. This is a pretty basic frog. It's really just a tiny little brown dude. I kind of gave it some points because it is pretty cute. They have these huge round eyes. They actually have a kind of a pointy nose. Their nose is a little bit v-shaped. Their markings have some variability, like some of them have yellow stripes down their back, some of them don't. They can kinda look a little bit different from one to the other. They don't all look the same. They don't all have the same markings.
Christian: Okay.
Ellen: I mean, they're pretty cute. They're nothing necessarily spectacular, but they have a pretty adorable little face as far as frogs go. It's a decently cute frog.
Christian: Okay.
Ellen: Yeah. So, going to wrap up the coquí by talking about some miscellaneous information, their conservation status is of least concern.
Christian: Good.
Ellen: In fact, coquís have been found as invasive species in Florida, California, and most importantly Hawaii.
Christian: Well.
Ellen: They are kind of wrecking shop in Hawaii. They apparently are a huge problem. So what happens is they come in undetected, either as eggs or as just tiny adults on imported plants. So they'll bring in like, bromeliads or other types of plants that are not native to that area. And the coquí is just so little, like you don't see it. You can just miss the entire frog, or it has like eggs on the plant or something. And then you bring that in and then they get everywhere and then they lay eggs and it just...
Christian: It's the perfect environment for them, too.
Ellen: It's very, yeah, it's very similar to what they're used to. So it's really easy for them to reproduce.
Christian: Probably fewer predators.
Ellen: No predators. Nothing in Hawaii will eat them, so they're just completely unchecked. This has happened in Florida a few times in the past, where coquí will sort of establish populations in South Florida, but Florida has the advantage of periodic freezes during the winter. Sometimes we'll have freezes, and those will usually kill off any coquí in that area. They can't really survive a freeze, but they can't really get a foothold in there. Like every once in a while there'll be a little flare up where like a bunch of them will show up, but they're not self-sustaining. You won't see a population of them lasting for a long time. However, in Hawaii, like I said, they have no natural predators to keep their populations in check. And in fact, in Hawaii there have been times when their population density was up to double or even triple what it was in Puerto Rico.
Christian: Dang.
Ellen: So this is like thousands and thousands and thousands of coquí in very small spaces.
Christian: So what is the impact? Is it eating important bugs or?
Ellen: Yes, so they're eating a lot of bugs. They're eating a lot of native insects. But also this is, I hadn't thought about this, but the excrement from the frogs changes the nutritional balance in the soil.
Christian: Yeah.
Ellen: So this is something that is okay for plants that are not native to Hawaii, but the plants that are native to Hawaii are used to a very, very different balance of nutrients in their soil. The plants that are native to Hawaii are used to that sort of volcanic soil, right? Where it's, it's very, very different from Puerto Rican soil. So when the coquí establish a big population, the poop that they're putting into the soil can really kinda change the ecosystem there.
Christian: I see.
Ellen: And they're also, you know, eating a lot of insects and they're competing with other predators in that area, so it's just not good.
Christian: Sure.
Ellen: And also another, not necessarily an ecological side effect, but an economical side effect is that they're very loud. They're extremely loud. Due to the density that they can establish in Hawaii, the sound produced by their calls can be completely deafening. You cannot hear anything over how loud they are. If they really get a foothold in an area, they can be so incredibly loud that you like, you can't even hear yourself think.
Christian: That's awful.
Ellen: You can hear them inside, like inside buildings, you can hear them because of how many there are and how loud they are. The Hawaii invasive species council describes them as "loud, incessant and annoying." That's not to devalue the importance of dealing with an invasive species that has really skyrocketed.
Christian: Honestly, I feel like the sound is the biggest problem and everything else is just secondary.
Ellen: Who knows? Maybe, I don't know. I don't know. I'm not on that council.
Christian: I think Hawaii in general is very, very careful about avoiding invasive species.
Ellen: Oh Gosh. It's like you can't take anything to Hawaii. Like you cannot take a plant, you cannot take a fruit, you cannot take an animal. Like you can't take your pet to Hawaii, they really have it on lock.
Christian: Yeah.
Ellen: So what's funny is that as negatively as they feel about the sound of the coquí because of how many there are there, that's in stark contrast to how Puerto Ricans feel about the sound of the coquí. Right?
Christian: Sure.
Ellen: So in Puerto Rico, their densities are much lower. They keep it to a reasonable volume. It's still loud, but it's very melodic. It sounds beautiful. They have that sort of melody to their call and it's, it does sound like music in the rain forest. It sounds really beautiful. They have really inspired a lot of art, they've inspired songs and poems and they've just really been a muse for artists from Puerto Rico and they're strongly associated with Puerto Rican identity.
Christian: That's awesome.
Ellen: Yeah, so I've been really charmed by this frog and I'm a big fan.
Christian: I think there's also a lot of music with influences from the coquí where the singer will imitate that sound.
Ellen: Oh yeah?
Christian: I heard a little bit of that while we were in San Juan.
Ellen: Yeah, it's- I can definitely see why they are so charming because I was reading an article from like the Puerto Rican tourism website that basically described their association as like, just like Puerto Rico, it's a small island, just like the coquí, we're small, but we have a big voice.
Christian: I like that.
Ellen: Yeah. So I was like, you know what? That makes sense. That makes sense. So, yeah, this is a great animal. I love the coquí and you know what? I didn't know anything about it before, like doing all this research, so...
Christian: That's fun.
Ellen: Yeah. Good animal. Thank you, Edwin.
Christian: Yes, thanks, Edwin.
Ellen: Before we move on to Christian's animal, just a real quick a shout out to our Patreon. We have a Patreon to help us grow, so if you want to help us out, if you want to support us and help us get bigger and better and also get access to some really cool stuff like a feed of the show with no ads and a patron-only discord and all sorts of other really cool stuff, come check us out at patreon.com/justthezooofus. For this week's episode, I want to thank our patrons, Briana Feinberg and Krystina Sanders.
Christian: Thanks, y'all!
Ellen: Thank you. Alright, Christian, what do you have for us this week?
Christian: For this week, I have the American Bombardier Beetle.
Ellen: Okay.
Christian: Scientific name, Brachinus fumans. Hope that's how that's pronounced.
Ellen: Sure. You're good.
Christian: This is the animal was requested by Jungle Gym Queen, as well as Sarah Beth Bradley.
Ellen: Thanks y'all. Good taste in bugs.
Christian: So, a lot of people have heard of the Bombardier beetle. That is actually a, you call it a grouping of several different species. I chose the American bombardier beetle just because of being local to us, I suppose. Although I don't think I've ever personally seen one of these.
Ellen: Definitely not.
Christian: And I'm pulling my information from also Animal Diversity Web, can be found at animaldiversity.org, and also MIT news, a particular article with which I will tell later, else giving away content.
Ellen: A grand reveal! No spoilers here.
Christian: But it can be found at news.mit.edu. So, a little quick talk about this beetle. Their adult size are about a half inch long, or one and a quarter centimeters long.
Ellen: Teeny.
Christian: Yeah. Not Big.
Ellen: It's like the claw of a chicken.
Christian: The fingernail? Bigger than that.
Ellen: Okay.
Christian: Yeah. You're trying to pull in them chickens. So these guys can be found, as the name might suggest, in North America in temperate zone woodlands and grasslands. They belong to the taxonomic family Carabidae, also known as ground beetles. As far as notable evolutionary relatives go, there's one called Panagaeus cruxmajor. I mentioned this one because it's interesting to look at. It's gold and black, and its markings look like it has a crucifix on it.
Ellen: Whoa.
Christian: Yes. And I also have a story towards the end of my segment that involves this particular crucifix beetle and Charles Darwin.
Ellen: So that's a little teaser for ya, stick around.
Christian: Yep. But kind of going back onto the family thing, this family includes 40,000 species.
Ellen: No, it does not. That's so many.
Christian: Sure does. I mean, now we're in the bug lands.
Ellen: That's true. Most animals are bugs. Most things are bugs.
Christian: Am I bug?
Ellen: Yes. We're all bugs.
Christian: So getting right into it. Effectiveness, this is where this particular species shines, in my opinion. I'm giving it an 8 out of 10.
Ellen: Alright. That's pretty good.
Christian: And that's because of what bombardier beetles are known for. To put it simply, bombardier beetles, they have a defense mechanism to where when they are threatened or startled, they will spray a hot toxin from their- the rear of their abdomen.
Ellen: Okay.
Christian: Let's talk about how that works a little bit.
Ellen: Yes, please.
Christian: So in the rear of the abdomen of the Beatles, they have two small glands. One produces hydrogen peroxide while the other makes hydroquinone. And then those two mix in a different part of the abdomen that is called the explosion chamber.
Ellen: No it's not!
Christian: It for sure is.
Ellen: Oh my gosh. This is a Zoid.
Christian: So these two- those two chemicals mix, and within that chamber is already two enzymes, catalase and peroxidase, and it's added into there to speed up the chemical reaction that takes place. So when these chemicals all come together, they produce a lot of heat and it reaches about the boiling point. So the temperature of this mixture, this cocktail of sorts reaches a hundred degrees Celsius, or 212 degrees Fahrenheit.
Ellen: There it is, okay.
Christian: It's heated up. It's creating a ton of pressure and then the beetle releases it as a steamy stream. This makes an audible pop when it happens.
Ellen: *popping sound*
Christian: Something like that, yeah. So yeah, it does this as a defense mechanism. So one, it's very hot and two, it's an irritant to most animals.
Ellen: Oh, so it's both hot and spicy.
Christian: Yeah.
Ellen: This a spicy gusher.
Christian: I don't suggest it though. Uh, and this reaction that's happening inside it happens in pulses.
Ellen: Oh, so it's not just like a stream?
Christian: Yeah, it's not a one and done thing.
Ellen: It's like just in case the first one wasn't enough.
Christian: Well it does a controlled pulse. It gets to the point where the pressure builds up to where the glands aren't able to put any more of the first two chemicals into the chamber, until it's released. It's a lot like an ignition chamber in a gasoline engine, actually.
Ellen: It sounds like it doesn't really have a lot of control over this.
Christian: It does, yes. So it's controlling these pulses and for how long it wants, but its control really comes into play with aim. So it has about 270 degrees of aim in any direction.
Ellen: Oh wow.
Christian: So it can effectively aim at wherever it wants.
Ellen: Does it ever accidentally like fire at itself or...?
Christian: So I've, I've seen it, I've seen videos of it doing this and I've seen it get its own leg or something. Cause usually in the videos, the way they prompt the response is they'll use tweezers or something to kinda like grab its back leg.
Ellen: Oh that's rude.
Christian: And they're like "Aah! *tssst*" and it'll usually get its own leg. It doesn't seem to do any damage. Something interesting there is that the anatomy of the beetles is in such a way that it doesn't harm its own internal organs with that said explosion chamber. So, and by the way, this is where the MIT article comes into play and that article was titled "How Some Beetles Produce a Scalding Defensive Spray."
Ellen: There it is.
Christian: So MIT was interested in it because of the potential applications in defense.
Ellen: Military defense.
Christian: Yeah. But also uh, engineering in general.
Ellen: Oh okay.
Christian: Right.
Ellen: I mean yeah they've basically got like a biological combustion chamber.
Christian: Right. Cause the inside of the beetle are such that, you know, some pieces are made to not expand under pressure whereas some are meant to expand but not permanently, and it's designed to retract back.
Ellen: Sure.
Christian: Just basic things going on inside it. Cause you know, you would wonder like how does it- how does it not blow itself up? So a lot of different insects do something like this, but what makes the bombardier beetle different is the reaction that makes it hot. The chemical itself, a lot of different insects use this kind of chemical, but the bombardier beetle can shoot it.
Ellen: Oh, a little extra sting to it.
Christian: Yeah. Yeah. They eat other bugs, a lot of which would be considered pests. So that's a plus.
Ellen: I'll take it.
Christian: Point off though: they cannot fly. They do have wings though, so they're considered vestigial.
Ellen: Oh man, you got the wings and you can't fly! Join the penguin club, I guess, man.
Christian: So just like, just like a lot of ground beetles, they have wings that are covered by like a cap over it.
Ellen: Sure, sure. It makes me think of like a scarab.
Christian: Yeah, just like that. Those caps are usually the prettiest part of beetles.
Ellen: It's decorative.
Christian: Moving on: Ingenuity. I gave it a 5 out of 10.
Ellen: That's probably the best they could have hope before.
Christian: I mean, it knows to use the chemical attack when it needs to.
Ellen: Sure. It probably takes a little bit of know-how to like, know how to aim.
Christian: I suppose.
Ellen: Get your trajectory right where you like you hit what you're going for, but not yourself?
Christian: I guess. Yeah.
Ellen: I guess it requires a fair amount of expertise. You're essentially a gunner.
Christian: Although there are situations where aim does not matter. For example, I saw a video of a toad eating one, not this particular species, but a bombardier beetle in general. And then of course, it does what it does best inside the toad, and the toad throws it back up.
Ellen: Oh really? Did the beetle survive?
Christian: Looked like it. Yeah.
Ellen: Wow! Man. Sure.
Christian: Since toads and frogs eat their things whole usually. Right?
Ellen: Yeah, that makes sense. Yeah. I guess they wouldn't really be trying to worry too much about like chewing it up and killing it first or anything.
Christian: Right.
Ellen: So I guess it would have that little escape opportunity.
Christian: Yep.
Ellen: That's pretty cool.
Christian: Yeah.
Ellen: You know, I like to give bonus points for like good, good, uh, evasive maneuvers.
Christian: Yeah. But again, I've considered that to be more of a...
Ellen: An effectiveness thing?
Christian: Yeah. And then the final category, aesthetics, 6 out of 10.
Ellen: That's not bad.
Christian: It's not the most interesting to look at as far as beetles go. It's not one of the pretty iridescent ones.
Ellen: Aw, man! I love those.
Christian: Yeah. So it's black and red, like a red orange mostly. The black part is its abdomen and the rest of it, like its head and its legs are reddish.
Ellen: It's a Sith beetle.
Christian: A what?
Ellen: Sith Beetle.
Christian: I don't know what- oh, a Sith, as in Star Wars?
Ellen: Yes! Because it's black and red.
Christian: Oh, okay. Yes. Excellent reference, wife unit.
Ellen: Thanks.
Christian: Alright. So that was my 6 out of 10 for aesthetics. Conservation status, there's no special listing.
Ellen: Sure.
Christian: Now, my fun little side story.
Ellen: The meat and potatoes. Let's get to it. I've been on pins and needles.
Christian: So this comes from the University of Cambridge, specifically their Darwin Correspondence Project. This comes from a letter that Darwin wrote to a Leonard Jenyns on October 17th, 1846.
Ellen: This is a throwback. Alright.
Christian: Yes. And it talks about the beetle that was related that I mentioned earlier, the Panagaeus cruxmajor.
Ellen: Okay.
Christian: The one that has a crucifix on its back.
Ellen: Cool. Cool, cool, cool, cool, cool.
Christian: And also before I go into it, just a reminder that the family is Carabidae, he will refer to it as Carabi. So I'm choosing a particular part of this letter. It's a pretty long letter, but this one I found interesting.
Ellen: An excerpt.
Christian: Yes. And it goes as such: I must tell you what happened to me on the banks of the Cam in my early entomological days; under a piece of bark I found two carabi (I forget which) & caught one in each hand, when lo & behold I saw a sacred Panagæus crux major; I could not bear to give up either of my Carabi, & to lose Panagæus was out of the question, so that in despair I gently seized one of the carabi between my teeth, when to my unspeakable disgust & pain the little inconsiderate beast squirted his acid down my throat & I lost both Carabi & Panagæus!"
Ellen: [laughter] Get wrecked! Oh my gosh. The, the... Audacity of this creature!
Christian: The little inconsiderate beast.
Ellen: You can- This is a letter that is what, 150 years old.
Christian: Yep.
Ellen: And you can just feel the seething like, frustration. The little inconsiderate beast! You can feel how mad he was. That is a timeless rage.
Christian: So I really enjoyed that.
Ellen: Gosh, I love that. You keep getting all these deep cuts, cause when what's his face was trash talking the manatee. You remember that?
Christian: Yep. I do remember that.
Ellen: That was a good one too. Dang.
Christian: So I think there might be a, I guess something to be taken away from this story. Something about greed or maybe the, you know... Bird in the hand worth two in the bush or something.
Ellen: A beetle in the teeth is...
Christian: Worth NOTHING.
Ellen: Is worth none in your hands.
Christian: So yeah.
Ellen: Oh my gosh. That was good. Oh, that's a good one. Thank you. Okay, so I guess the implication here is that like, he put a, uh, bombardier beetle...?
Christian: Wasn't a bombardier beetle. So remember I said a lot of these kinds of beetles will expel this kind of irritant.
Ellen: Oh, I see I see I see.
Christian: So I'm thinking this was the kind that was not a bombardier beetle, so it wasn't like super, super hot, but it was still an irritant.
Ellen: Okay, cool.
Christian: Yeah.
Ellen: Gosh, that's good.
Christian: So that's all I have for the American bombardier beetle.
Ellen: Good stuff. Thank you, my love.
Christian: Yes, and thank you again from Jungle Gym Queen and Sarah Beth Bradley.
Ellen: Yes. I have some audience responses that I'd like to share with you all.
Ellen: What'd you got for us?
Ellen: So this comes from our buddy, the Jungle Gym Queen, who also on Facebook goes as the Nagging Naturalist. Same Person. Yep. Twitter: Jungle Gym Queen, Facebook: Nagging Naturalist, who has a lot of really, really cool nature and conservation-based like, content. So very, very good stuff. Check them out on Facebook. So the Nagging Naturalist says in response to our peacock mantis shrimp segment in episode 19: "I have to contest Christian's peacock mantis shrimp score, or at least a feature he used towards their score, because for all of those color cones-" you remember how we talked about the color comes in the eyes of the peacock mantis shrimp- "peacock mantis shrimp can't actually process color the way we do. Being able to see more light waves than us doesn't necessarily mean they are good at interpreting what they're seeing. They're poor at discriminating between colors. However, when looking at what their photoreceptors focus on, it reveals that they have six receptors dedicated to processing on the UV spectrum as well as special crystalline cones that help filter UV specific wavelengths entering through their eyes. So being able to see UV light is thought to contribute to their communication, since they use polarized light to talk. Deep Look PBS did a good job covering the topic a few years ago," and then, uh, goes on to say "Counterpoint to my own, I have to give them props for having six pupils and hexnocular vision," as opposed to our vision, which is binocular, because two pupils. Theirs is hexnocular because they have six pupils. So I actually, I actually did look up this Deep Look PBS video on their vision and it was really interesting because it translated the light that they're seeing into light that we would be able to see, and it shows how they signal their location to each other using UV light that is visible to them, but not to us or anything else.
Christian: How do they produce the UV light though?
Ellen: It's not that they produce the light, it's that they have... I don't know if it's scales, but like their fins reflect that light that they can see that nobody else can see.
Christian: Okay. I guess they're just reflecting like the UV from the sun.
Ellen: Yup. Yup. They're just reflecting that light that nobody else would be able to pick up. This reminded me a little bit of when we were talking about the praying mantis having compound eyes, and you know, other bugs that have compound eyes, but the praying mantis having compound eyes doesn't necessarily mean that they see better than us because yes, they have very, very, very many eyes, but they don't see particularly well. So this is an example of quantity not necessarily meaning quality.
Christian: I see.
Ellen: Yeah.
Christian: Heh.
Ellen: So- Oh, do you now? Do you see? Spectacular. Thank you. All right. That's all I have. All right. Well, thank you so much to you, the listener for joining us this week as we hope you will every week forever for the rest of our lives as we continue making this show.
Christian: And even then after we upload our consciousness to a, uh...
Ellen: A hivemind.
Christian: I'm going to say a sentient otamatone.
Ellen: Okay, so we're going to have procedurally generated AI-concocted episodes. I really want to hear that. I like, I want to see someone do that thing where they take like, transcripts of our show- which are available on justthezooofus.com by the way- and feed it into like an AI program and then get a deep fake like, have like an AI-generated....
Christian: "I made this AI read a thousand hours of Just the Zoo of Us transcripts and this is what it came up with," it's just 5 pages of fartboat.
Ellen: Which has been retired, and then brought back by now, by the way, and that's some deep lore from our Facebook group. But so anyway, sorry for all of that that you just heard, but...
Christian: I'm not.
Ellen: Thank you to everybody who's been listening, especially especially thank you to people who have been telling your friends about us and reviewing us and rating us on your podcatchers. It means a lot to us and it makes us really happy and it makes us want to keep making this show, so thank you for doing that. You can connect with us on Facebook, Twitter, or Instagram. Just just search the title of the show. You'll get there.
Christian: Yeah.
Ellen: Also please come hang out with us in our really cool and awesome Facebook group that's called Just the Zoo of Us: Official Friend Squad. It's like the best group ever and you guys are really great and you make it an awesome group.
Christian: Good stuff.
Christian: We've been having a great time. If you have an animal species you want to hear us review, you can submit those to us. You can hit us up on social media and get those to us, or if you'd rather you can email them to us at ellen@justthezooofus.com. A transcript of this episode and all the other episodes can be found at www.justthezooofus.com and last note, I want to thank Louie Zong for the use of his song "Adventuring" off of his album, Bee Sides.
Ellen: Always a pleasure to listen to.
Christian: Yup. We love it. In fact, you're about to hear it right now. Here it comes.
Christian: Oh!
Ellen: Bye!
Christian: Bye yall!