Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lamb.
And I'm Joe McCormick, and we're back part two in the Halloween season series. We're calling the Bone Collectors about organisms in nature that form Texas chainsaw massacre style collections of bones and other dead body parts. In the last episode, we talked first about the extinct cave hyena Crocutispialia, which
was a Eurasian apex predator of the Pleistocene Epic. These animals are famous for assembling these big pits of animal bones that are now found preserved in caves and the caves where they lived around the world, and that in itself provides interesting information about the adaptive characteristics of these animals, mainly the fact that we sort of talked about them as like a tractor model predator or scavenger, that they were strong, had these powerful jaws, and I think, maybe
for some reasons of social cooperation as well, were able to haul large amounts of animal carcass mass from kill sites or from scavenging sites out in the world all the way back to their dens, which were often in caves and then you find these assemblages of bones in the caves.
Yeah. Yeah, they're kind of like tow trucks. They're out there, they find a carcass that's been illegally parked, and they're like, well, we got to take this back to the garage.
And then after that we talked about an insect native to a small stretch of forest in a mountain range on the Hawaiian island of Oahu, nicknamed the bone collector caterpillar because of its unusual behavior of first of all, living inside active spider webs and then covering its external silk case with dead, dried out insect body parts shopped from the spider's web, which there's no perfect analogy for on our level, but I was thinking about it, like
if there were a species of bird that lived inside a Kentucky fried chicken and primarily eight chicken scavenged from people's tables, and completely covered the outside of its body with leftover chicken bones so as not to be mistaken by the people working there for like another chicken that should be cooked or something.
I like it. You know, make this a terror bird and put humans on the menu, and you've got yourself a horror movie right here.
I think now.
In the case of the bone collector caterpillar, the reason for the chopped up insect body part suit behavior is not known with certainty, but researchers kind of suggested that it may be a form of camouflage to protect the caterpillar from the spider that it lives alongside. Somehow disguising the caterpillar as trash something to be ignored. And we're back today to talk about more so, Robin.
Sorry what, oh no, It's just it would be kind of like if you were at a child's birthday party and you covered yourself in the crust of pizza slices and the bottom parts of cupcakes, you know, the parts that the children buy and large do not eat, and they would mark yourself safe from them, I guess, yeah, yeah.
Or you're a piece of Halloween candy that eats Halloween candy, that disguises yourself by covering yourself in candy wrappers.
There you go, that work.
You would look like, what's already done with? I don't need to pay attention to that anymore. That's for mom and dad to clean up. Yeah, now, rob, if you don't mind I was going to kick things off today looking at a wasp. Would you like to do that?
Oh?
Yeah, I'm always game for another horror story from the world of the wasp.
There's a lot to choose from there. So in the last episode, since we talked about the bone collector caterpillar, I guess it's obvious that we've expanded our criteria for collectors beyond literal bones. We're not just looking at uses for the internal skeletons of vertebrate animals. Because to be frank, you know, I was looking at a lot of things we could have talked about. I think some of the best examples just come from the invertebrate world. That's where
a lot of the best stuff happens. So I wanted to kick things off by talking about another insect example, and that is the bone house wasp. The scientific name for the species is Deuterogenia osorium. Ooh yeah, And that species name, you might hear that in your brain there osorium. That comes from the word ossuary if you're not familiar.
And ossuary is a storage space that could be a box or something bigger, like a whole room or a hall for the storage of human bones often used in places where burial space is limited or at a premium, So a common practice in many places would be that when a person dies, they are buried or entombed in
a temporary spot. Later, maybe a year later, after the decomposition of the soft tissue, the bones are cleaned and removed from the temporary burial space and transferred to an ossuary, which could be a bone box or a chest, or a space beneath the tomb, or just like a whole bone building. Sometimes there are places with shelves crammed with bones or rooms lined with bones. It's just another place to put the bones. Now, why would a species of wasp be named after a bone storage box, Well, we
will answer that question. This wasp was described in a paper from twenty fourteen called a Unique Nest Protection Strategy in a New Species of Spider Wasp, published in the Journal Plus One by authors Michael Stobb, Michael ol Choudong Xu, and Alexandra Maria Klein, and I was reading a bit
of background. Apparently, these insects were collected during a biodiversity survey in the forests of Jungshi Province in southeast China, where the researchers collected more than eight hundred chambered nests from the wild and in the environment you would usually find these nests. You would find them sometimes like dug into the earth, or you would also find them maybe in natural cavities or holes that have been bored into
pieces of wood. It'll be kind of like deep tube shaped chambers, either in earth or in wood or something like that. So these chambered nests, they were found in the wild and then they were brought back to the laboratory so that the researchers could examine the nests and rear the larvae. In the larvae inside quote here we describe a surprising nesting behavior that was previously unknown in the entire animal kingdom, the use of a vestibular cell
filled with dead ants. So some houses have a mud room, you know, sort of the outer room between the front door and then where the house proper begins. These nests have an anti chamber like that, called the vestibular cell. It's an ant room and it's filled with dead ant bodies.
Rob I've got.
A photo of a cross section of a nest for you to look at in the outline here, so you can see the nest has a what you might think of as a shotgun house design. It's deep and narrow and deeper. You have what are called the brood cells. This is where the wasp eggs are protected, sealed in with these cemented doors made of maybe plant material, soil, debris, and mud. And then in the outermost chamber you can see this dusty jumble of mangled ant skeletons, just a wad of dead ants.
Oh wow, yeah, this is incredible and you know, for many of us, speaking at least for the two of us, but I think a lot of people out there. You've grown up in an area that had a lot of dirt dobber wafts or mud dabbers, various names, you would inevitably figure out that they do a similar thing with spiders, where you'd find this cache of spiders hidden away inside their mud nests.
Oh, these wasps do that with spiders too. We're actually going to get a two for one here. Oh yeah, yeah, so we're going to get ants and spiders in the same nest. It's a smorgasboard of invertebrate horror. But so the question is why.
The ant bone room.
While the authors discuss they start the paper by talking about different evolutionary specializations in reproductive strategy, noting that certain wasp species will specialize in trying to protect and ensure the survival of a smaller number of total eggs compared to the majority of their close insect relatives, which lay more eggs but invest less in the survival of each one. So the majority of soft flies and wasp females will be able to lay hundreds of eggs in a lifetime.
But what the authors call the quote more advanced solitary nest provisioning hymenoptera that they sometimes lay only a dozen eggs or so, or even less than that in the lifetime of a single female. So lay far fewer eggs, but do a lot more to protect each one. And the bone house wasp is in the latter group, the kind that invests a lot more in each egg. It is a solitary nest provisioning wasp in the family Pompility. The pompility are also known as the spider hunting wasps.
And here we come back to what you talked about with the spiders earlier. Within this family, Curiously, the adults actually don't eat spiders. The adults feed mostly on plant nectar, and they're vegetarians. They are not generally carnivores, and yet they are some of the most fearful predators in a way in nature, I guess, depending on how you want
to use the word predator. They're not eating spiders, but they do attack spiders with a painful, paralyzing venom, not so that the adults themselves can eat the spiders, but so that the spiders can be entombed as a live, non decomposing food source for their growing young. So yes, these spiders in many cases, in most cases, will be eaten alive in a paralyzed state. So the life cycle for a spider hunting wasp usually goes like this. You have adults, which you can feed on floral nectar. They
produce this paralyzing sting. They use the paralyzing sting to attack and immobilize a spider, then they carry the spider away. They lay their eggs alongside the paralyzed spider inside a protected nest of some sort, often a hole or a tube of some kind closed to the outside, to protect the egg and the larva once it hatches, and I guess presumably also to protect the spider as a food source from being stolen. You know, you want to lock up the fridge.
Hey, just don't leave that lane around.
Yeah yeah, it's like a bare box, you know, the roadbox.
Yeah.
Yeah. And so the larvae hatch inside these protected nests and they eat the spiders, usually starting instinctually with non vital body parts, eating you know, eat, chewing through the cuticle on the outside of the spider, eating the body parts first that will not be lethal to the spider, and then finally working their ways to the vital organs, you know, eating the heart and the central nervous system
and stuff. And the goal is to keep the paralyzed spider alive as long as possible so that it doesn't decompose. It kind of keeps the spider alive while entombed, to take advantage of the spider's living physiology, like it's immune system as a natural preservative.
Yeah. I mean it may sound cruel to us, but you know, it's a wasp larva eat spider world out there.
I mean, it's efficient, waste not want not.
Yeah.
Yeah.
So they oh and then finally, of course, the larvae they mature, they might pupate, emerge from the nest to become these nectivorous adults and repeat the cycle. So everything I just said is also the case for the bone house wasp. These are these spider hunting solitary wasps. But what separates the bonehouse wasp from its nest provisioning kin is that the bone house wasp also goes to the extra trouble of provisioning the nest with an outer chamber what the authors of the paper will call again a
vestibular cell crammed with dead ants. Now, when I was first reading about this, and I hadn't gotten to the reasoning part of it yet, the first place my brain went was, oh, bonus snack. Right, so you got your spider and then you've got something else. My young will emerge extra well fed because not only do they get to eat a paralyzed spider alive bit by bit, they also get to eat some ants for dessert. But no,
the ants are not there to be eaten. In fact, the ants in the vestibular chamber are completely ignored by the larvae. The larvae never eat or come into contact with them.
Wow, okay, all right, so what are they for? Right? Yeah? They can't be a decorative garnish. Surely they have to have some purpose.
Yeah, they're closed up in there, right, so what are
they for? Interestingly, the authors note that many other Hymenoptera species construct tubular nests with these outer chambers or vestibular cells, but they're usually empty, and at the time of this paper their function was not really known because previous research had thought, well, you know, maybe these are protective in some way, this outer empty chamber, it protects the brood inside, But previous research had not shown these vestibular cells to
have any protective benefit for the eggs or larvae inside. So what are they for? Because to be clear, protection is a concern. I mean, these organisms sound very fearsome because what they attack spiders and they paralyze them and they eat them alive. But still the young are vulnerable. You know, you can have an adult parasitoid or predator parasite of another species attack the nest, and the young, the eggs or the larvae will be very vulnerable.
Inside.
There are other wasp and fly species that will readily attack the nests and eat the eggs and larvae of these solitary spider hunting wasps if they can get in there. So the brood inside would benefit from protection. But these commonly found empty vestibular cells don't seem to provide much, if any protection, at least as far as we can tell. Experimentally. However, the authors of this paper found that when the vestibular chamber is stuffed with dead ants, it seems it actually
does provide a protective advantage. The dead ants help keep nest parasites and predators out. So how do they do that? Well, the authors raise a couple of possibilities which are not mutually exclusive, chemical camouflage and chemical defense. Quote ants produce a diverse array of organic compounds, including species specific cuticular hydrocarbons or cchs, which are a central part of the
nest mate recognition system. Being long chained molecules of low volatility, cchs persist on the cuticula of dead Hymenoptera for a long time period, thus giving do Osarium nests the scent
of an ant colony. So you've got these cuticular hydrocarbons that these chemical signals that persist on the body of dead ants for a long time, and they keep the brood chambers of the young wasps smelling like an ant colony, and if you are an inse, even a predator or a parasite, you usually don't want to mess with an ant colony. It's like in Grand Theft Auto when you like go on the military base or something. You know, it's just like instant, overwhelming defensive response.
Yes, yeah, it's it's quite a heist. As we alluded to in the last episode. You can have specialists that can do it, but it is it's a high risk environment.
The author is right quote. In this context, we find it particularly interesting that the numerically dominating ant species ind Osarium nests is p astuda, an aggressive, large bodied, and common species in the study region that has a powerful sting. So they seem to be not just collecting any ant. They're trying to get a certain kind of ant in
this dead ant room. And what they're selecting for the ant bone box is an ant that is big and ferocious with nasty venom, is stinky, and is common and likely to have been encountered by local nest attacking insects.
Yes, oh wow, Okay, now it's all coming together.
The author's right quote. The proposed function of the ant chamber is most effective against predators that break the nest and against parasitic wasps that penetrate the nest with their long ovipositor that would be an egg laying appendage, so trying to put their own eggs inside the nest. Such parasitoids attacked other trapped nesting wasps, including other pompility in the study region, and may also attack Doosarium by penetrating
the wood that contains naturally the nest cavity. However, such species were never found in nests of Doosarium, which was only attacked by parasitoids which entered the nest prior to the construction of the ant chamber. So the ant chambers keep the bad guys out and they protect the brood within. And the authors note again that this is the first case of a species of wasp found in nature to build a nest chamber full of ant carcasses. Wonder nature is.
But getting back to our horror movie parallels. You know, last time we were talking about some distinctions different kinds of things that can be signaled when in a horror context you encounter a big collection of bones, you have like the Midden style collection of bones, where it just
you know, it suggests non intelligent chaotic predation. This is just a trash pile that signals lots of death versus the carefully assembled or curated collection of bones that are creepy in a different way that suggests fascination or kind of aberrant obsessions or behavior. This example makes me think about the sort of Texas chainsaw massacre implications in a different way. You know, what if you imagine, okay, the
saw your family and the Texas chainsaw masker. Yeah, they got a bunch of bones around, But we always assume that it's because they're being aggressive. What if it's not because they're trying to terrify their victims for the fun of it. They're not salting the meat. What if it is to frighten onlookers in a defensive way, much like the ants in this nest, to get them to stay away from the house, avoid the brood.
Yeah, yeah, that is kind of the vibe here. It's so fascinating to think about because again we're talking about an animal that is harvesting other animals, but not for food, but for essentially building materials and to serve as a protective barrier. Yeah, and I mean it's really hard to
think of any other species. I'm just off the top of my head outside of human beings that actually do this sort of thing where I look to the natural world and identify one living species not as food but as something that should be killed for other purposes.
Yeah, that is interesting, and to be fair, I don't think this too closely. Could actually fit the events of TCM if you watch it, but I don't know. I'm imagining an alternate version of TCM where they line the outside of the house with like, I don't know, they've they've gone out and gotten a bunch of malt like guards. Yeah, security guards from all kinds of places, and then they just post up the security guard uniforms outside their house.
Mmmm yeah, yeah, yeah. Yeah. It's not something that necessarily translates completely to the human world, but within the world of like insect communication, you can see how it would speak volumes.
Either way, I think this definitely fits more into the curated assemblage of remains than into the chaotic midden formula, because these are not leftovers, like they were put in there for a reason.
Right right, Yeah, this is a great example. All right. I have a couple of other examples I want to get to here in this episode. I'm gonna start though, by returning to the decapod world. As we mentioned in the last episode, hermit crabs are essentially the crab superstars of pilfering the quote unquote bones. Again, we're being a little liberal in our usage of the word bones of the dead for their own use, the bones in this case being the shells of mollusks that they use as their own armor.
Hm.
But they are not the only decapods to get in in this sort of action. Famously, we also have the decorator crabs of the Superfamily majority. Now, not every species in this family is a decorator crab. It's more broadly considered I think the home of the spider crabs, but still that's where we find decorator crabs. And there are also other crabs outside of the superfamily that use similar adaptations,
such as the kelp crab. And we also might compare this to the way pom Pom crabs or boxer crabs carry sea enemies around one in each claw or one on each claw, kind of brandishing them as living weapons.
Yeah yeah, Well, these things have come up on the show a bit before, and I never thought about them in a creepy context or in a bone collector kind of way, go thinking, okay, maybe they're attaching various sessile organisms to their back. This seems kind of hospitable in a way.
I mean, they're grabbing animals and using them as weapons. It would be like if there was a guy running around the subway with a rat in each hand, chasing at your people. You know, we would be it would be a little off putting.
Yeah, But with the crabs, it's so cute.
Yeah, all right, so let's consider this this next example then, yeah, the decorator crabs. So essentially, what decorator crabs do is they camouflage themselves by considering their living environment, you know, but not simply mimicking it with you know, their coloration or their morphology, but by taking bits of that environment, living parts of that environment in many cases, and sticking that to their body. Essentially, they have the cetae on
their backs, like on their carapace. These are like little hooklike often compared to velcrow situations, all over their shell and this allows them to just reach out, strip a little some living or non living portion of their environment and just slap it on there and then this becomes
part of their protective array. Has pointed out in a nineteen eighty Scientific American article about decorator crabs by Mary kay Wixton, other kinds of seta on the shell are more sensory, and their job is not to hold stuff in place so much, but to sort of keep track of where everything is. So it would seem to be a situation where it's not just completely slap dash. It's carefully arranged. They are decorating to a certain degree. Things go in the right place, and they have to remain there.
The crabs they get pretty picky about this. Like if, as we've discussed before, a crab a decorator crab, like other crabs, it has to molt. Its body grows, but its shell doesn't. They have to ditch the shell that it outgrew and then you know, grow a new one. And when they do this, they will have to then reattach their zoo garden back onto their new shell as
it grows. So this is interesting to think about. Now, once they reach maturity, you know, they stop molting and they're good to go, but there are going to be these cases where they're like, okay, this this jacket doesn't fit me anymore, but I have all of these great enamel pins on it and patches, so I have to take all those off and then put them on the new jacket, the new gene jacket, once I grow it out of my body. So yeah, there are number of
interesting details concerning this practice. So, first of all, body size apparently plays a role in all of this, has discussed in two thousand and nine's Evolution of Decoration in the Majodia Crab by holtgrin at All, published in the American Naturalists. Smaller bodied crabs would seem to have a more economically sustainable time with a strategy, and this seems to break down to the idea that the more body you have, the more hooks you have to have, and
that has, you know, a cost to it. It's like having a whole bunch of antlers on your head as a vertebrate. So larger decorator crabs seem to rely less on this sort of thing, and the smaller varieties of decorator crabs, you know, are more all in on the decoration.
Interesting, okay, Yeah.
There are also some varieties that are more passive decorators than others. So you know, they might just stuff just kind of sticks to them and that becomes their camouflage, while others are definitely involved in decorating themselves. I was looking at some much older papers about these guys, and some of the authors really got in on comparing these crabs to humans, saying that they were essentially getting dressed
when they they put stuff on. And I guess it's hard not to make that comparison, do I look all right?
Yeah?
Now, most famously, I think most of the when you hear people talk about the decorator crebs, we're generally talking about living material that has been added. So you know, there might be some sort of algae that they're stripping and sticking to them, or they're getting a little piece of an anemone or a bit of a sponge slapping that onto the shell, essentially becoming a mobile habitat for sessile marine organisms. So not the bones, but the actual living meat of their environment.
Yes, I like this reframing here. So they are getting the meat.
Yes, And as Wixton pointed out in that paper I referenced earlier, the exact favored materials are going to differ from species to species, and it's also going to be situationally specific. So I don't know if you could even maybe even press it as far as to say, like individually specific, but it's going to be based on what's available to them as well, not so much the individual preference, but you know, just what do they have in their area.
In general, they tend to favor organic matter that they can strip apart with their claws, sponges again, algae and stuff like that. They will also go for, quote, according to Wixton, tubes secreted by polykeet worms, which sounds super gross at first, it's less gross when you look into it. Basically, these are these self secreted mineral tubes that some polykeet worms secrete and then live in. Other worms just live
in tubes that they've bored into a substrate. So we're talking about little mineralized worm straws turned stylish accessories for the decorator crabs.
Wow, this wreck.
This reminds me of the caterpillar from the last time, which had all these things that looked like little orange straws attached to it, but it was the spider body integument, like from the spider molting. It would have a tube left over that I guess used to be part of a spider's leg and then the spider outgrew it.
Yeah.
Yeah, you can look up pictures of this, and some of these pictures are wild and also, I guess it makes sense. We talk about decoration, but it is camouflage, so some of these it's sometimes kind of hard to really pick out and figure out what you're looking at. But you do see these what look like tiny, little, you know, environment colored straws stuck to the crabs bodies.
They'll also make use of other materials, though plant leaves have available, and in captive environments where they've been stripped of their decorations, Wiston points out that they'll use the likes of quote, torn sea pansies, strips of paper, chips of cement from the aquarium wall, and even bits of hamburger.
Uh.
Yeah, I don't know. I guess they put hamburger in there for food and they're like, what is this it'll do? And they stick it to their bodies.
Yeah, I want more detail on the hamburger.
I couldn't find any additional day. I think it's just they put hamburger in there, I guess to see how they would respond to the meat, and at least one of the crabs is like, okay, this.
Will do to meat. Yeah.
These to be clear situations where their actual decorations were taken away from them, so they did not have the option of using their normal, like first choice decorations. Now, they'll certainly make use of shell fragments. But as for actual bones, if we're going to be like real strict about the episode title here, it seems possible that bones could be covered by the frequently cited miscellaneous detritus that the crabs use. But it would seem that actual vertebrate
bones on the whole are just not desirable. And part of this may be that, you know, sometimes bones are too large, they're too massive. Other cases, the coloration might not be ideal because again the crab seems to be selecting, you know, based on what looks like my environment, and so you can imagine that if a bone is too bright looking, then well that might just not that might
not pass the test for the decorator crab in question. Now, based on researcher observations of decoration and captivity, which we decided, it seems possible that, okay, maybe you could manipulate one into using tiny bones. But that seems like cheating. I mean, it's like they're not going to put Hamburger on.
Their bodies in the wild.
So if you were able to trick one into using bones well in a captive environment, that doesn't really count.
Well you've convinced me Rob. I did not think of these these animals in a creepy way before I put them in the cute box in my brain. But I'm officially taking them out of the cute box. Or I'll take half of one out of the cute box and put the leave one half in there, put the other half in the creepy box.
I don't know. Aren't all crabs kind of in the creepy and cute box at the same time. That's kind of the crab box, isn't it.
Maybe?
Yeah, At any rate, they're pretty fun.
Yeah.
They certainly do cover themselves with a mix of living flesh, dead flesh, and various forms of organic and inorganic detritus. So yeah, certainly close enough for me.
Bone collector certified.
Yeah, all right, And then I want to get back to one that I might have mentioned this one in passing in the first episode. Uh, certainly one that's been on my mind the whole time, especially when we're talking about a creature's midden, and that is the midden of the octopus, and this one was that. Yeah, this was one of my first picks for the series, as it's a pretty great example of a creature that not only passively accumulates bones and bone like remains, but also makes use of them.
Oh okay, so it could could be in sort of both of our categories from the first episode, both the chaotically assembled midden as a leftover of other activities, but then also something that serves a purpose of its own. It's not just a trash heap.
Right right, it is. It's in this case it is a trash sheep, but then a trash heap that is utilized in environment manipulation and dim manipulation, which we'll get into in just a second. All right, So, different varieties of octopus make use of mittens. This includes the common octopus, the giant Pacific octopus, the gloomy octopus, and the Caribbean two spot octopus just as a few examples. And we'll get into some more specific examples here in a second.
And an octopus's midden is primarily the accumulation of shells and bones. Outside of its den, there are also going to be bits of rock and perhaps bits of coral and so forth. They are kind of like mixed up in it as well. One thing that was interesting This is a kind of a tangent, but I think it reveals a lot about the formation of middens. In some cases the shells don't accumulate as much because hermit crabs
carry them off. So Richard F. Ambrose discussed this in a nineteen eighty three article for Marine Behavior and Physiology, citing studies of Virel's two spot octopus, which only have, according to this older paper, some discarded remnants at their dens twenty percent of the time without the materials forming true middens. So again, this would seem to be a variety of octopus that doesn't really do much with mittens.
And the big reason for this would seem to be that the snails make up an extra large part of this specific octopus species diet much more than other octopus species, and as a result, it has mostly shells that are hermit crabs. They get stolen and carried away by marine hermit crabs.
Well, isn't that a beautiful little emergent efficiency in nature, Like exactly the main kind of trash you produce is exactly what some other organism in your environment wants as a home.
Yes, though I don't know in this case those as
we'll look at some of these other examples. Other midden producing octopuses do make use of their heap of bones and shells, and you know, some of those shells are carried away if they happen to be mollis shells, and there are hermit crabs in their environment, but they're able to do more with them, whereas this particular species Varil's two spot octopus, I guess just doesn't have that option if most of it's most of it's midden or most of what would be its midden are carried away by hermits.
So one octopus's trash does not ever get to become that same octopus as treasure because it was already treasure to a decapod that took it.
Right right, So so yeah, on one level, the octopus is midden is yeah, definitely this bone and shell deposit. Again, in keeping with our her mythic ideas of dragons layers, the cave of Carabanog and so forth, you know, look at the bones. And I have to mention that every time I've had the opportunity to go snorkeling, I always keep a lookout for anything that might be an octopus midden, because to observe an octopus in the lie in the
wild is a most special thing. And the one time I really got to observe an octopus out out in the wild while snorkeling during daylight, that was one of the most magical experiences of my life. It was just amazing. But of course octopuses are not always active when we snorkelers are out, and even when they are, they are masters of disguise in their environments and we're merely humans. So I am not good at identifying an octopus as midden in the wild.
You know.
I'll look at things and be like, that kind of looks like it could be a heap of shells, that could be some bones. Maybe that is an octopus's midden, but you know, nothing ever comes out of it.
Well, that actually makes me wonder would they make any attempt to disguise their middens.
As far as I know, not intentionally, you know, I guess part of the reality is there's you know, things are eaten all the time, things are torn apart all the time in a marine environment, especially in like a really diverse coral environment. So uh yeah, But this is I guess, kind of an open question, like are there going to be organisms that might identify an octopus as midden and therefore try to take advantage of it or steer clear of it? I would think not so much,
because one is, we'll discuss here in a minute. One of the key things that the octopus does was with the midden is disguise its layer and fortify its layer.
Okay, that makes sense, And I guess.
As you alluded to a minute ago, you know, there's gonna be a lot of shells and other bones and hard parts floating around or settling on the bottom of the ocean anyway, So like it wouldn't be unusual to see.
Those for another organism.
It's not like it's not like when we see a bone pile in a movie.
Yeah. Now, just because I can't spot an octopus midden in the wild or haven't had the luck of spotting one, that doesn't mean other humans, actual researchers and experts can't. Because it kind of much like the example of the cave hyena bone collections we discussed in last episode, Octopus middens can actually tell us a lot about what octopus species are eating, you know, it gives us a little insight into what's on the menu for them, and it
can also tell us what octopus individuals are eating. And this latter point is actually really key.
Oh you can go through their trash. Yeah, yeah, you.
Can go through their trash. And it's telling again, not just about a species, but also about individuals. As discussed in individual prey Choices of Octopuses Are they Generalist or Specialist?
By Mather at All, published twenty twelve in the journal Current Zoology, The question they pose here may have to be answered in terms of both species and individual given that we're dealing with intelligent and adaptive predators that may make their choices based not only on localized prey of availability, but also individual personality differences, which I thought was a
very very interesting consideration. Like, we're dealing with a creature that is again highly adaptive, may have a lot to choose from in a given environment, and some of its choices might not just be part of a basic equation of like availability plus ability, and you know the abilities of the species, but also like, what does this individual like to do? What has it chosen to explore and then take advantage.
Of Octopuses are intelligent enough that they might actually be quirky individually quirky.
Yes, Yeah, another paper I looked two thousand and eighths Octopus vulgaris. That's the common octopus, by the way, in the Caribbean is a specializing generalist by Anderson at All,
published in the Marine Ecology Progress series. They looked at the remains of six hundred and forty nine prey items gathered from the middens of thirty eight dens in a small area off the Caribbean island of bon Air, and they these middens revealed thirty five species of gastropods it's nineteen percent of the total, nineteen bivalves fifty percent, and
twenty one crustaceans thirty percent. And this particular study argued that, yes, the common octopus is a specialized gennalist, with the population as a whole boasting a wide choice of prey items, but with narrower focus for the individual. So that would seem to line up with what this other paper was saying as well, But.
A minute ago you were talking about the actual benefits of an octopus as mitten, so that it wasn't just a trash heap. It is thought to do something for the octopus.
That's right.
And then this we can really think of it in terms of a dragon or a killer rabbit. So your killer rabbit or your dragon is producing all of these bones. But imagine that the mythic monster in question here, first of all, pushes or blasts all the bones that they produce outside of their den. They don't want to sleep on all those bones necessarily, And in the octopus's case, they can use, you know, their jets to things around. So you're accumulating your waist out there in front of
your den. With the dragon or the rabbit, we're talking about a cave, and with the octopus, you know, we're talking about some sort of indention in the sand, the coral and so forth, you know, the rock, some sort of little den they have there with sand and other detritus out there already, and then an ever growing pile of bones and bits of shell and so forth, and so yeah, it's not just a waste disposal byproduct, but it's also a source of defense and shelter because the
heap of shells and bones are then used by the octopus to alter the environment. They can use it to narrow or even block the entrance to the octopus's den, camouflaging it and also fortifying it against incursion. So such a den like it provides them a place of refuge, but it can also serve a very much more important part, like the most important part really in the octopus's life cycle. It can serve as the place where a female octopus lays her eggs and eventually her final resting place as
she dies tending to them. So most species of octopus only reproduce once in their lifetime, and they enter a fatal sinessence phase after laying that clutch of eggs. So you know, it's rather interesting. It becomes their home, it kind of becomes their tomb, but is also the place from which the next phase of the life cycle will emerge.
And then afterwards, an octopuss den might be reused by a new octopus seeking out a place to hold up, or of course it could be inhabited by various other marine organisms looking for some sort of little place to burrow away. But in comparing the octopus is Midden to
dragons and other fantasy creatures. I think there's an opportunity there, And I wonder if any body out there has explored this idea, like some sort of dragon that uses its bones for some sort of purpose, you know, either fortifying its position or I don't know, I guess they're dragons. They could potentially do something magical with them, like raise all those bones. I imagine there's easily some cases where that goes on. But the octopus would argue, no, the
best thing you can do is create. You end up with this big, like sifting pile of bones and sand and other materials, and you can just use that as kind of like the door to your layer, opening it, closing it, partially obscuring and so forth.
Yeah, so this is kind of similar to the wasp and ant example.
Here.
Once again it's a case of defensive use of the bones or remains of another animal.
Yeah. Absolutely, Yeah, you know, and in this case that these bones are the result of their own consumption, unlike the ants. But yeah, they are using them for a novel purpose. To come back to your Texas chainsaw massacre example, it would be like if the saw your family. We're using the bones not only as decorations, but as like actual like fences to keep people out, like physical barriers. I guess that's the only thing that makes sense. Oh, I can't really say environmental disguise, but.
Well, I was thinking, like, what about lining their driveway with bones in a way that like narrows the approach of vehicles to the home. You know, you're trying to funnel them into a particular area. Yeah, so yeah, you said that the octopuses could like narrow you know, or control the shape of the opening or the aperture to their den with the bones.
Yeah, yeah, yeah, I could see that.
Yeah, there's a lot we can learn from the Sawyer clan. I think that's what we're saying.
Putting a bunch of sharp bones out on the road in front of the house to puncture the tires of trucks that are going by. Yeah yeah, I guess that's that's getting away from the octopus example.
But well, things become increasingly more complicated when you start injecting them into the human world. But I think the spirit is still there.
You know, here's a funny thing. Imagine octopuses they developed their own technological civilization, their own art, their own genres of literature. They discovered that they had a taste for horror as well. They liked being scared for fun. Now, try to imagine the culture's equivalent of bone imagery, because they've only got one hard part, right, it's just the beak, So they couldn't have a whole bunch of different bones for horror imagery. It would just be beaks.
I guess you're right.
Yeah, their pirate flag is just a beak. Every piece of skullar bone imagery we have could only be beak.
That would be their Halloween decoration.
Yeah, all right? Does that do it for the bone collectors?
I think it does now. Folks out there, you might have some other examples that have come to mind. You're like, hey, what about this organism? What about that one? Well, write in because we would love to either discuss those on future episodes of Listener, may here in the Stuff to Blow your Mind podcast feed, or who knows, if we get enough recommendations, maybe we have the ammo to do a part three, either later this year or next year when Halloween rolls around once again.
Oh yeah.
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