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 Lamb.
Speaker 3: And I'm Joe McCormick, and we're back part two in
Speaker 3: the Halloween season series. We're calling the Bone Collectors about
Speaker 3: organisms in nature that form Texas chainsaw massacre style collections
Speaker 3: of bones and other dead body parts. In the last episode,
Speaker 3: we talked first about the extinct cave hyena Crocutispialia, which
Speaker 3: was a Eurasian apex predator of the Pleistocene Epic. These
Speaker 3: animals are famous for assembling these big pits of animal
Speaker 3: bones that are now found preserved in caves and the
Speaker 3: caves where they lived around the world, and that in
Speaker 3: itself provides interesting information about the adaptive characteristics of these animals,
Speaker 3: mainly the fact that we sort of talked about them
Speaker 3: as like a tractor model predator or scavenger, that they
Speaker 3: were strong, had these powerful jaws, and I think, maybe
Speaker 3: for some reasons of social cooperation as well, were able
Speaker 3: to haul large amounts of animal carcass mass from kill
Speaker 3: sites or from scavenging sites out in the world all
Speaker 3: the way back to their dens, which were often in
Speaker 3: caves and then you find these assemblages of bones in
Speaker 3: the caves.
Speaker 2: Yeah. Yeah, they're kind of like tow trucks. They're out there,
Speaker 2: they find a carcass that's been illegally parked, and they're like, well,
Speaker 2: we got to take this back to the garage.
Speaker 3: And then after that we talked about an insect native
Speaker 3: to a small stretch of forest in a mountain range
Speaker 3: on the Hawaiian island of Oahu, nicknamed the bone collector
Speaker 3: caterpillar because of its unusual behavior of first of all,
Speaker 3: living inside active spider webs and then covering its external
Speaker 3: silk case with dead, dried out insect body parts shopped
Speaker 3: from the spider's web, which there's no perfect analogy for
Speaker 3: on our level, but I was thinking about it, like
Speaker 3: if there were a species of bird that lived inside
Speaker 3: a Kentucky fried chicken and primarily eight chicken scavenged from
Speaker 3: people's tables, and completely covered the outside of its body
Speaker 3: with leftover chicken bones so as not to be mistaken
Speaker 3: by the people working there for like another chicken that
Speaker 3: should be cooked or something.
Speaker 2: I like it. You know, make this a terror bird
Speaker 2: and put humans on the menu, and you've got yourself
Speaker 2: a horror movie right here.
Speaker 4: I think now.
Speaker 3: In the case of the bone collector caterpillar, the reason
Speaker 3: for the chopped up insect body part suit behavior is
Speaker 3: not known with certainty, but researchers kind of suggested that
Speaker 3: it may be a form of camouflage to protect the
Speaker 3: caterpillar from the spider that it lives alongside. Somehow disguising
Speaker 3: the caterpillar as trash something to be ignored. And we're
Speaker 3: back today to talk about more so, Robin.
Speaker 2: Sorry what, oh no, It's just it would be kind
Speaker 2: of like if you were at a child's birthday party
Speaker 2: and you covered yourself in the crust of pizza slices
Speaker 2: and the bottom parts of cupcakes, you know, the parts
Speaker 2: that the children buy and large do not eat, and
Speaker 2: they would mark yourself safe from them, I guess, yeah, yeah.
Speaker 3: Or you're a piece of Halloween candy that eats Halloween candy,
Speaker 3: that disguises yourself by covering yourself in candy wrappers.
Speaker 4: There you go, that work.
Speaker 3: You would look like, what's already done with? I don't
Speaker 3: need to pay attention to that anymore. That's for mom
Speaker 3: and dad to clean up. Yeah, now, rob, if you
Speaker 3: don't mind I was going to kick things off today
Speaker 3: looking at a wasp. Would you like to do that?
Speaker 4: Oh?
Speaker 2: Yeah, I'm always game for another horror story from the
Speaker 2: world of the wasp.
Speaker 3: There's a lot to choose from there. So in the
Speaker 3: last episode, since we talked about the bone collector caterpillar,
Speaker 3: I guess it's obvious that we've expanded our criteria for
Speaker 3: collectors beyond literal bones. We're not just looking at uses
Speaker 3: for the internal skeletons of vertebrate animals. Because to be frank,
Speaker 3: you know, I was looking at a lot of things
Speaker 3: we could have talked about. I think some of the
Speaker 3: best examples just come from the invertebrate world. That's where
Speaker 3: a lot of the best stuff happens. So I wanted
Speaker 3: to kick things off by talking about another insect example,
Speaker 3: and that is the bone house wasp. The scientific name
Speaker 3: for the species is Deuterogenia osorium. Ooh yeah, And that
Speaker 3: species name, you might hear that in your brain there osorium.
Speaker 3: That comes from the word ossuary if you're not familiar.
Speaker 3: And ossuary is a storage space that could be a
Speaker 3: box or something bigger, like a whole room or a
Speaker 3: hall for the storage of human bones often used in
Speaker 3: places where burial space is limited or at a premium,
Speaker 3: So a common practice in many places would be that
Speaker 3: when a person dies, they are buried or entombed in
Speaker 3: a temporary spot. Later, maybe a year later, after the
Speaker 3: decomposition of the soft tissue, the bones are cleaned and
Speaker 3: removed from the temporary burial space and transferred to an ossuary,
Speaker 3: which could be a bone box or a chest, or
Speaker 3: a space beneath the tomb, or just like a whole
Speaker 3: bone building. Sometimes there are places with shelves crammed with
Speaker 3: bones or rooms lined with bones. It's just another place
Speaker 3: to put the bones. Now, why would a species of
Speaker 3: wasp be named after a bone storage box, Well, we
Speaker 3: will answer that question. This wasp was described in a
Speaker 3: paper from twenty fourteen called a Unique Nest Protection Strategy
Speaker 3: in a New Species of Spider Wasp, published in the
Speaker 3: Journal Plus One by authors Michael Stobb, Michael ol Choudong Xu,
Speaker 3: and Alexandra Maria Klein, and I was reading a bit
Speaker 3: of background. Apparently, these insects were collected during a biodiversity
Speaker 3: survey in the forests of Jungshi Province in southeast China,
Speaker 3: where the researchers collected more than eight hundred chambered nests
Speaker 3: from the wild and in the environment you would usually
Speaker 3: find these nests. You would find them sometimes like dug
Speaker 3: into the earth, or you would also find them maybe
Speaker 3: in natural cavities or holes that have been bored into
Speaker 3: pieces of wood. It'll be kind of like deep tube
Speaker 3: shaped chambers, either in earth or in wood or something
Speaker 3: like that. So these chambered nests, they were found in
Speaker 3: the wild and then they were brought back to the
Speaker 3: laboratory so that the researchers could examine the nests and
Speaker 3: rear the larvae. In the larvae inside quote here we
Speaker 3: describe a surprising nesting behavior that was previously unknown in
Speaker 3: the entire animal kingdom, the use of a vestibular cell
Speaker 3: filled with dead ants. So some houses have a mud room,
Speaker 3: you know, sort of the outer room between the front
Speaker 3: door and then where the house proper begins. These nests
Speaker 3: have an anti chamber like that, called the vestibular cell.
Speaker 3: It's an ant room and it's filled with dead ant bodies.
Speaker 4: Rob I've got.
Speaker 3: A photo of a cross section of a nest for
Speaker 3: you to look at in the outline here, so you
Speaker 3: can see the nest has a what you might think
Speaker 3: of as a shotgun house design. It's deep and narrow
Speaker 3: and deeper. You have what are called the brood cells.
Speaker 3: This is where the wasp eggs are protected, sealed in
Speaker 3: with these cemented doors made of maybe plant material, soil, debris,
Speaker 3: and mud. And then in the outermost chamber you can
Speaker 3: see this dusty jumble of mangled ant skeletons, just a
Speaker 3: wad of dead ants.
Speaker 2: Oh wow, yeah, this is incredible and you know, for
Speaker 2: many of us, speaking at least for the two of us,
Speaker 2: but I think a lot of people out there. You've
Speaker 2: grown up in an area that had a lot of
Speaker 2: dirt dobber wafts or mud dabbers, various names, you would
Speaker 2: inevitably figure out that they do a similar thing with spiders,
Speaker 2: where you'd find this cache of spiders hidden away inside
Speaker 2: their mud nests.
Speaker 3: Oh, these wasps do that with spiders too. We're actually
Speaker 3: going to get a two for one here. Oh yeah, yeah,
Speaker 3: so we're going to get ants and spiders in the
Speaker 3: same nest. It's a smorgasboard of invertebrate horror. But so
Speaker 3: the question is why.
Speaker 4: The ant bone room.
Speaker 3: While the authors discuss they start the paper by talking
Speaker 3: about different evolutionary specializations in reproductive strategy, noting that certain
Speaker 3: wasp species will specialize in trying to protect and ensure
Speaker 3: the survival of a smaller number of total eggs compared
Speaker 3: to the majority of their close insect relatives, which lay
Speaker 3: more eggs but invest less in the survival of each one.
Speaker 3: So the majority of soft flies and wasp females will
Speaker 3: be able to lay hundreds of eggs in a lifetime.
Speaker 3: But what the authors call the quote more advanced solitary
Speaker 3: nest provisioning hymenoptera that they sometimes lay only a dozen
Speaker 3: eggs or so, or even less than that in the
Speaker 3: lifetime of a single female. So lay far fewer eggs,
Speaker 3: but do a lot more to protect each one. And
Speaker 3: the bone house wasp is in the latter group, the
Speaker 3: kind that invests a lot more in each egg. It
Speaker 3: is a solitary nest provisioning wasp in the family Pompility.
Speaker 3: The pompility are also known as the spider hunting wasps.
Speaker 3: And here we come back to what you talked about
Speaker 3: with the spiders earlier. Within this family, Curiously, the adults
Speaker 3: actually don't eat spiders. The adults feed mostly on plant nectar,
Speaker 3: and they're vegetarians. They are not generally carnivores, and yet
Speaker 3: they are some of the most fearful predators in a
Speaker 3: way in nature, I guess, depending on how you want
Speaker 3: to use the word predator. They're not eating spiders, but
Speaker 3: they do attack spiders with a painful, paralyzing venom, not
Speaker 3: so that the adults themselves can eat the spiders, but
Speaker 3: so that the spiders can be entombed as a live,
Speaker 3: non decomposing food source for their growing young. So yes,
Speaker 3: these spiders in many cases, in most cases, will be
Speaker 3: eaten alive in a paralyzed state. So the life cycle
Speaker 3: for a spider hunting wasp usually goes like this. You
Speaker 3: have adults, which you can feed on floral nectar. They
Speaker 3: produce this paralyzing sting. They use the paralyzing sting to
Speaker 3: attack and immobilize a spider, then they carry the spider away.
Speaker 3: They lay their eggs alongside the paralyzed spider inside a
Speaker 3: protected nest of some sort, often a hole or a
Speaker 3: tube of some kind closed to the outside, to protect
Speaker 3: the egg and the larva once it hatches, and I
Speaker 3: guess presumably also to protect the spider as a food
Speaker 3: source from being stolen. You know, you want to lock
Speaker 3: up the fridge.
Speaker 2: Hey, just don't leave that lane around.
Speaker 4: Yeah yeah, it's like a bare box, you know, the roadbox.
Speaker 2: Yeah.
Speaker 3: Yeah. And so the larvae hatch inside these protected nests
Speaker 3: and they eat the spiders, usually starting instinctually with non
Speaker 3: vital body parts, eating you know, eat, chewing through the
Speaker 3: cuticle on the outside of the spider, eating the body
Speaker 3: parts first that will not be lethal to the spider,
Speaker 3: and then finally working their ways to the vital organs,
Speaker 3: you know, eating the heart and the central nervous system
Speaker 3: and stuff. And the goal is to keep the paralyzed
Speaker 3: spider alive as long as possible so that it doesn't decompose.
Speaker 3: It kind of keeps the spider alive while entombed, to
Speaker 3: take advantage of the spider's living physiology, like it's immune
Speaker 3: system as a natural preservative.
Speaker 2: Yeah. I mean it may sound cruel to us, but
Speaker 2: you know, it's a wasp larva eat spider world out there.
Speaker 4: I mean, it's efficient, waste not want not.
Speaker 2: Yeah.
Speaker 4: Yeah.
Speaker 3: So they oh and then finally, of course, the larvae
Speaker 3: they mature, they might pupate, emerge from the nest to
Speaker 3: become these nectivorous adults and repeat the cycle. So everything
Speaker 3: I just said is also the case for the bone
Speaker 3: house wasp. These are these spider hunting solitary wasps. But
Speaker 3: what separates the bonehouse wasp from its nest provisioning kin
Speaker 3: is that the bone house wasp also goes to the
Speaker 3: extra trouble of provisioning the nest with an outer chamber
Speaker 3: what the authors of the paper will call again a
Speaker 3: vestibular cell crammed with dead ants. Now, when I was
Speaker 3: first reading about this, and I hadn't gotten to the
Speaker 3: reasoning part of it yet, the first place my brain
Speaker 3: went was, oh, bonus snack. Right, so you got your
Speaker 3: spider and then you've got something else. My young will
Speaker 3: emerge extra well fed because not only do they get
Speaker 3: to eat a paralyzed spider alive bit by bit, they
Speaker 3: also get to eat some ants for dessert. But no,
Speaker 3: the ants are not there to be eaten. In fact,
Speaker 3: the ants in the vestibular chamber are completely ignored by
Speaker 3: the larvae. The larvae never eat or come into contact
Speaker 3: with them.
Speaker 2: Wow, okay, all right, so what are they for? Right? Yeah?
Speaker 2: They can't be a decorative garnish. Surely they have to
Speaker 2: have some purpose.
Speaker 3: Yeah, they're closed up in there, right, so what are
Speaker 3: they for? Interestingly, the authors note that many other Hymenoptera
Speaker 3: species construct tubular nests with these outer chambers or vestibular cells,
Speaker 3: but they're usually empty, and at the time of this
Speaker 3: paper their function was not really known because previous research
Speaker 3: had thought, well, you know, maybe these are protective in
Speaker 3: some way, this outer empty chamber, it protects the brood inside,
Speaker 3: But previous research had not shown these vestibular cells to
Speaker 3: have any protective benefit for the eggs or larvae inside.
Speaker 3: So what are they for? Because to be clear, protection
Speaker 3: is a concern. I mean, these organisms sound very fearsome
Speaker 3: because what they attack spiders and they paralyze them and
Speaker 3: they eat them alive. But still the young are vulnerable.
Speaker 3: You know, you can have an adult parasitoid or predator
Speaker 3: parasite of another species attack the nest, and the young,
Speaker 3: the eggs or the larvae will be very vulnerable.
Speaker 4: Inside.
Speaker 3: There are other wasp and fly species that will readily
Speaker 3: attack the nests and eat the eggs and larvae of
Speaker 3: these solitary spider hunting wasps if they can get in there.
Speaker 3: So the brood inside would benefit from protection. But these
Speaker 3: commonly found empty vestibular cells don't seem to provide much,
Speaker 3: if any protection, at least as far as we can tell. Experimentally. However,
Speaker 3: the authors of this paper found that when the vestibular
Speaker 3: chamber is stuffed with dead ants, it seems it actually
Speaker 3: does provide a protective advantage. The dead ants help keep
Speaker 3: nest parasites and predators out. So how do they do that? Well,
Speaker 3: the authors raise a couple of possibilities which are not
Speaker 3: mutually exclusive, chemical camouflage and chemical defense. Quote ants produce
Speaker 3: a diverse array of organic compounds, including species specific cuticular
Speaker 3: hydrocarbons or cchs, which are a central part of the
Speaker 3: nest mate recognition system. Being long chained molecules of low volatility,
Speaker 3: cchs persist on the cuticula of dead Hymenoptera for a
Speaker 3: long time period, thus giving do Osarium nests the scent
Speaker 3: of an ant colony. So you've got these cuticular hydrocarbons
Speaker 3: that these chemical signals that persist on the body of
Speaker 3: dead ants for a long time, and they keep the
Speaker 3: brood chambers of the young wasps smelling like an ant colony,
Speaker 3: and if you are an inse, even a predator or
Speaker 3: a parasite, you usually don't want to mess with an
Speaker 3: ant colony. It's like in Grand Theft Auto when you
Speaker 3: like go on the military base or something. You know,
Speaker 3: it's just like instant, overwhelming defensive response.
Speaker 2: Yes, yeah, it's it's quite a heist. As we alluded
Speaker 2: to in the last episode. You can have specialists that
Speaker 2: can do it, but it is it's a high risk environment.
Speaker 3: The author is right quote. In this context, we find
Speaker 3: it particularly interesting that the numerically dominating ant species ind
Speaker 3: Osarium nests is p astuda, an aggressive, large bodied, and
Speaker 3: common species in the study region that has a powerful sting.
Speaker 3: So they seem to be not just collecting any ant.
Speaker 3: They're trying to get a certain kind of ant in
Speaker 3: this dead ant room. And what they're selecting for the
Speaker 3: ant bone box is an ant that is big and
Speaker 3: ferocious with nasty venom, is stinky, and is common and
Speaker 3: likely to have been encountered by local nest attacking insects.
Speaker 2: Yes, oh wow, Okay, now it's all coming together.
Speaker 3: The author's right quote. The proposed function of the ant
Speaker 3: chamber is most effective against predators that break the nest
Speaker 3: and against parasitic wasps that penetrate the nest with their
Speaker 3: long ovipositor that would be an egg laying appendage, so
Speaker 3: trying to put their own eggs inside the nest. Such
Speaker 3: parasitoids attacked other trapped nesting wasps, including other pompility in
Speaker 3: the study region, and may also attack Doosarium by penetrating
Speaker 3: the wood that contains naturally the nest cavity. However, such
Speaker 3: species were never found in nests of Doosarium, which was
Speaker 3: only attacked by parasitoids which entered the nest prior to
Speaker 3: the construction of the ant chamber. So the ant chambers
Speaker 3: keep the bad guys out and they protect the brood within.
Speaker 3: And the authors note again that this is the first
Speaker 3: case of a species of wasp found in nature to
Speaker 3: build a nest chamber full of ant carcasses. Wonder nature is.
Speaker 3: But getting back to our horror movie parallels. You know,
Speaker 3: last time we were talking about some distinctions different kinds
Speaker 3: of things that can be signaled when in a horror
Speaker 3: context you encounter a big collection of bones, you have
Speaker 3: like the Midden style collection of bones, where it just
Speaker 3: you know, it suggests non intelligent chaotic predation. This is
Speaker 3: just a trash pile that signals lots of death versus
Speaker 3: the carefully assembled or curated collection of bones that are
Speaker 3: creepy in a different way that suggests fascination or kind
Speaker 3: of aberrant obsessions or behavior. This example makes me think
Speaker 3: about the sort of Texas chainsaw massacre implications in a
Speaker 3: different way. You know, what if you imagine, okay, the
Speaker 3: saw your family and the Texas chainsaw masker. Yeah, they
Speaker 3: got a bunch of bones around, But we always assume
Speaker 3: that it's because they're being aggressive. What if it's not
Speaker 3: because they're trying to terrify their victims for the fun
Speaker 3: of it. They're not salting the meat. What if it
Speaker 3: is to frighten onlookers in a defensive way, much like
Speaker 3: the ants in this nest, to get them to stay
Speaker 3: away from the house, avoid the brood.
Speaker 2: Yeah, yeah, that is kind of the vibe here. It's
Speaker 2: so fascinating to think about because again we're talking about
Speaker 2: an animal that is harvesting other animals, but not for food,
Speaker 2: but for essentially building materials and to serve as a
Speaker 2: protective barrier. Yeah, and I mean it's really hard to
Speaker 2: think of any other species. I'm just off the top
Speaker 2: of my head outside of human beings that actually do
Speaker 2: this sort of thing where I look to the natural
Speaker 2: world and identify one living species not as food but
Speaker 2: as something that should be killed for other purposes.
Speaker 3: Yeah, that is interesting, and to be fair, I don't
Speaker 3: think this too closely. Could actually fit the events of
Speaker 3: TCM if you watch it, but I don't know. I'm
Speaker 3: imagining an alternate version of TCM where they line the
Speaker 3: outside of the house with like, I don't know, they've
Speaker 3: they've gone out and gotten a bunch of malt like guards. Yeah,
Speaker 3: security guards from all kinds of places, and then they
Speaker 3: just post up the security guard uniforms outside their house.
Speaker 2: Mmmm yeah, yeah, yeah. Yeah. It's not something that necessarily
Speaker 2: translates completely to the human world, but within the world
Speaker 2: of like insect communication, you can see how it would
Speaker 2: speak volumes.
Speaker 3: Either way, I think this definitely fits more into the
Speaker 3: curated assemblage of remains than into the chaotic midden formula,
Speaker 3: because these are not leftovers, like they were put in
Speaker 3: there for a reason.
Speaker 2: Right right, Yeah, this is a great example. All right.
Speaker 2: I have a couple of other examples I want to
Speaker 2: get to here in this episode. I'm gonna start though,
Speaker 2: by returning to the decapod world. As we mentioned in
Speaker 2: the last episode, hermit crabs are essentially the crab superstars
Speaker 2: of pilfering the quote unquote bones. Again, we're being a
Speaker 2: little liberal in our usage of the word bones of
Speaker 2: the dead for their own use, the bones in this
Speaker 2: case being the shells of mollusks that they use as
Speaker 2: their own armor.
Speaker 1: Hm.
Speaker 2: But they are not the only decapods to get in
Speaker 2: in this sort of action. Famously, we also have the
Speaker 2: decorator crabs of the Superfamily majority. Now, not every species
Speaker 2: in this family is a decorator crab. It's more broadly
Speaker 2: considered I think the home of the spider crabs, but
Speaker 2: still that's where we find decorator crabs. And there are
Speaker 2: also other crabs outside of the superfamily that use similar adaptations,
Speaker 2: such as the kelp crab. And we also might compare
Speaker 2: this to the way pom Pom crabs or boxer crabs
Speaker 2: carry sea enemies around one in each claw or one
Speaker 2: on each claw, kind of brandishing them as living weapons.
Speaker 3: Yeah yeah, Well, these things have come up on the
Speaker 3: show a bit before, and I never thought about them
Speaker 3: in a creepy context or in a bone collector kind
Speaker 3: of way, go thinking, okay, maybe they're attaching various sessile
Speaker 3: organisms to their back. This seems kind of hospitable in
Speaker 3: a way.
Speaker 2: I mean, they're grabbing animals and using them as weapons.
Speaker 2: It would be like if there was a guy running
Speaker 2: around the subway with a rat in each hand, chasing
Speaker 2: at your people. You know, we would be it would
Speaker 2: be a little off putting.
Speaker 4: Yeah, But with the crabs, it's so cute.
Speaker 2: Yeah, all right, so let's consider this this next example then, yeah,
Speaker 2: the decorator crabs. So essentially, what decorator crabs do is
Speaker 2: they camouflage themselves by considering their living environment, you know,
Speaker 2: but not simply mimicking it with you know, their coloration
Speaker 2: or their morphology, but by taking bits of that environment,
Speaker 2: living parts of that environment in many cases, and sticking
Speaker 2: that to their body. Essentially, they have the cetae on
Speaker 2: their backs, like on their carapace. These are like little
Speaker 2: hooklike often compared to velcrow situations, all over their shell
Speaker 2: and this allows them to just reach out, strip a
Speaker 2: little some living or non living portion of their environment
Speaker 2: and just slap it on there and then this becomes
Speaker 2: part of their protective array. Has pointed out in a
Speaker 2: nineteen eighty Scientific American article about decorator crabs by Mary
Speaker 2: kay Wixton, other kinds of seta on the shell are
Speaker 2: more sensory, and their job is not to hold stuff
Speaker 2: in place so much, but to sort of keep track
Speaker 2: of where everything is. So it would seem to be
Speaker 2: a situation where it's not just completely slap dash. It's
Speaker 2: carefully arranged. They are decorating to a certain degree. Things
Speaker 2: go in the right place, and they have to remain there.
Speaker 2: The crabs they get pretty picky about this. Like if,
Speaker 2: as we've discussed before, a crab a decorator crab, like
Speaker 2: other crabs, it has to molt. Its body grows, but
Speaker 2: its shell doesn't. They have to ditch the shell that
Speaker 2: it outgrew and then you know, grow a new one.
Speaker 2: And when they do this, they will have to then
Speaker 2: reattach their zoo garden back onto their new shell as
Speaker 2: it grows. So this is interesting to think about. Now,
Speaker 2: once they reach maturity, you know, they stop molting and
Speaker 2: they're good to go, but there are going to be
Speaker 2: these cases where they're like, okay, this this jacket doesn't
Speaker 2: fit me anymore, but I have all of these great
Speaker 2: enamel pins on it and patches, so I have to
Speaker 2: take all those off and then put them on the
Speaker 2: new jacket, the new gene jacket, once I grow it
Speaker 2: out of my body. So yeah, there are number of
Speaker 2: interesting details concerning this practice. So, first of all, body
Speaker 2: size apparently plays a role in all of this, has
Speaker 2: discussed in two thousand and nine's Evolution of Decoration in
Speaker 2: the Majodia Crab by holtgrin at All, published in the
Speaker 2: American Naturalists. Smaller bodied crabs would seem to have a
Speaker 2: more economically sustainable time with a strategy, and this seems
Speaker 2: to break down to the idea that the more body
Speaker 2: you have, the more hooks you have to have, and
Speaker 2: that has, you know, a cost to it. It's like
Speaker 2: having a whole bunch of antlers on your head as
Speaker 2: a vertebrate. So larger decorator crabs seem to rely less
Speaker 2: on this sort of thing, and the smaller varieties of
Speaker 2: decorator crabs, you know, are more all in on the decoration.
Speaker 4: Interesting, okay, Yeah.
Speaker 2: There are also some varieties that are more passive decorators
Speaker 2: than others. So you know, they might just stuff just
Speaker 2: kind of sticks to them and that becomes their camouflage,
Speaker 2: while others are definitely involved in decorating themselves. I was
Speaker 2: looking at some much older papers about these guys, and
Speaker 2: some of the authors really got in on comparing these
Speaker 2: crabs to humans, saying that they were essentially getting dressed
Speaker 2: when they they put stuff on. And I guess it's
Speaker 2: hard not to make that comparison, do I look all right?
Speaker 4: Yeah?
Speaker 2: Now, most famously, I think most of the when you
Speaker 2: hear people talk about the decorator crebs, we're generally talking
Speaker 2: about living material that has been added. So you know,
Speaker 2: there might be some sort of algae that they're stripping
Speaker 2: and sticking to them, or they're getting a little piece
Speaker 2: of an anemone or a bit of a sponge slapping
Speaker 2: that onto the shell, essentially becoming a mobile habitat for
Speaker 2: sessile marine organisms. So not the bones, but the actual
Speaker 2: living meat of their environment.
Speaker 4: Yes, I like this reframing here. So they are getting
Speaker 4: the meat.
Speaker 2: Yes, And as Wixton pointed out in that paper I
Speaker 2: referenced earlier, the exact favored materials are going to differ
Speaker 2: from species to species, and it's also going to be
Speaker 2: situationally specific. So I don't know if you could even
Speaker 2: maybe even press it as far as to say, like
Speaker 2: individually specific, but it's going to be based on what's
Speaker 2: available to them as well, not so much the individual preference,
Speaker 2: but you know, just what do they have in their area.
Speaker 2: In general, they tend to favor organic matter that they
Speaker 2: can strip apart with their claws, sponges again, algae and
Speaker 2: stuff like that. They will also go for, quote, according
Speaker 2: to Wixton, tubes secreted by polykeet worms, which sounds super
Speaker 2: gross at first, it's less gross when you look into it. Basically,
Speaker 2: these are these self secreted mineral tubes that some polykeet
Speaker 2: worms secrete and then live in. Other worms just live
Speaker 2: in tubes that they've bored into a substrate. So we're
Speaker 2: talking about little mineralized worm straws turned stylish accessories for
Speaker 2: the decorator crabs.
Speaker 4: Wow, this wreck.
Speaker 3: This reminds me of the caterpillar from the last time,
Speaker 3: which had all these things that looked like little orange
Speaker 3: straws attached to it, but it was the spider body integument,
Speaker 3: like from the spider molting. It would have a tube
Speaker 3: left over that I guess used to be part of
Speaker 3: a spider's leg and then the spider outgrew it.
Speaker 4: Yeah.
Speaker 2: Yeah, you can look up pictures of this, and some
Speaker 2: of these pictures are wild and also, I guess it
Speaker 2: makes sense. We talk about decoration, but it is camouflage,
Speaker 2: so some of these it's sometimes kind of hard to
Speaker 2: really pick out and figure out what you're looking at.
Speaker 2: But you do see these what look like tiny, little,
Speaker 2: you know, environment colored straws stuck to the crabs bodies.
Speaker 2: They'll also make use of other materials, though plant leaves
Speaker 2: have available, and in captive environments where they've been stripped
Speaker 2: of their decorations, Wiston points out that they'll use the
Speaker 2: likes of quote, torn sea pansies, strips of paper, chips
Speaker 2: of cement from the aquarium wall, and even bits of hamburger.
Speaker 4: Uh.
Speaker 2: Yeah, I don't know. I guess they put hamburger in
Speaker 2: there for food and they're like, what is this it'll do?
Speaker 2: And they stick it to their bodies.
Speaker 4: Yeah, I want more detail on the hamburger.
Speaker 2: I couldn't find any additional day. I think it's just
Speaker 2: they put hamburger in there, I guess to see how
Speaker 2: they would respond to the meat, and at least one
Speaker 2: of the crabs is like, okay, this.
Speaker 4: Will do to meat. Yeah.
Speaker 2: These to be clear situations where their actual decorations were
Speaker 2: taken away from them, so they did not have the
Speaker 2: option of using their normal, like first choice decorations. Now,
Speaker 2: they'll certainly make use of shell fragments. But as for
Speaker 2: actual bones, if we're going to be like real strict
Speaker 2: about the episode title here, it seems possible that bones
Speaker 2: could be covered by the frequently cited miscellaneous detritus that
Speaker 2: the crabs use. But it would seem that actual vertebrate
Speaker 2: bones on the whole are just not desirable. And part
Speaker 2: of this may be that, you know, sometimes bones are
Speaker 2: too large, they're too massive. Other cases, the coloration might
Speaker 2: not be ideal because again the crab seems to be selecting,
Speaker 2: you know, based on what looks like my environment, and
Speaker 2: so you can imagine that if a bone is too
Speaker 2: bright looking, then well that might just not that might
Speaker 2: not pass the test for the decorator crab in question. Now,
Speaker 2: based on researcher observations of decoration and captivity, which we decided,
Speaker 2: it seems possible that, okay, maybe you could manipulate one
Speaker 2: into using tiny bones. But that seems like cheating. I mean,
Speaker 2: it's like they're not going to put Hamburger on.
Speaker 4: Their bodies in the wild.
Speaker 2: So if you were able to trick one into using
Speaker 2: bones well in a captive environment, that doesn't really count.
Speaker 3: Well you've convinced me Rob. I did not think of
Speaker 3: these these animals in a creepy way before I put
Speaker 3: them in the cute box in my brain. But I'm
Speaker 3: officially taking them out of the cute box. Or I'll
Speaker 3: take half of one out of the cute box and
Speaker 3: put the leave one half in there, put the other
Speaker 3: half in the creepy box.
Speaker 2: I don't know. Aren't all crabs kind of in the
Speaker 2: creepy and cute box at the same time. That's kind
Speaker 2: of the crab box, isn't it.
Speaker 4: Maybe?
Speaker 2: Yeah, At any rate, they're pretty fun.
Speaker 4: Yeah.
Speaker 2: They certainly do cover themselves with a mix of living flesh,
Speaker 2: dead flesh, and various forms of organic and inorganic detritus.
Speaker 2: So yeah, certainly close enough for me.
Speaker 4: Bone collector certified.
Speaker 2: Yeah, all right, And then I want to get back
Speaker 2: to one that I might have mentioned this one in
Speaker 2: passing in the first episode. Uh, certainly one that's been
Speaker 2: on my mind the whole time, especially when we're talking
Speaker 2: about a creature's midden, and that is the midden of
Speaker 2: the octopus, and this one was that. Yeah, this was
Speaker 2: one of my first picks for the series, as it's
Speaker 2: a pretty great example of a creature that not only
Speaker 2: passively accumulates bones and bone like remains, but also makes
Speaker 2: use of them.
Speaker 3: Oh okay, so it could could be in sort of
Speaker 3: both of our categories from the first episode, both the
Speaker 3: chaotically assembled midden as a leftover of other activities, but
Speaker 3: then also something that serves a purpose of its own.
Speaker 3: It's not just a trash heap.
Speaker 2: Right right, it is. It's in this case it is
Speaker 2: a trash sheep, but then a trash heap that is
Speaker 2: utilized in environment manipulation and dim manipulation, which we'll get
Speaker 2: into in just a second. All right, So, different varieties
Speaker 2: of octopus make use of mittens. This includes the common octopus,
Speaker 2: the giant Pacific octopus, the gloomy octopus, and the Caribbean
Speaker 2: two spot octopus just as a few examples. And we'll
Speaker 2: get into some more specific examples here in a second.
Speaker 2: And an octopus's midden is primarily the accumulation of shells
Speaker 2: and bones. Outside of its den, there are also going
Speaker 2: to be bits of rock and perhaps bits of coral
Speaker 2: and so forth. They are kind of like mixed up
Speaker 2: in it as well. One thing that was interesting This
Speaker 2: is a kind of a tangent, but I think it
Speaker 2: reveals a lot about the formation of middens. In some
Speaker 2: cases the shells don't accumulate as much because hermit crabs
Speaker 2: carry them off. So Richard F. Ambrose discussed this in
Speaker 2: a nineteen eighty three article for Marine Behavior and Physiology,
Speaker 2: citing studies of Virel's two spot octopus, which only have,
Speaker 2: according to this older paper, some discarded remnants at their
Speaker 2: dens twenty percent of the time without the materials forming
Speaker 2: true middens. So again, this would seem to be a
Speaker 2: variety of octopus that doesn't really do much with mittens.
Speaker 2: And the big reason for this would seem to be
Speaker 2: that the snails make up an extra large part of
Speaker 2: this specific octopus species diet much more than other octopus species,
Speaker 2: and as a result, it has mostly shells that are
Speaker 2: hermit crabs. They get stolen and carried away by marine
Speaker 2: hermit crabs.
Speaker 3: Well, isn't that a beautiful little emergent efficiency in nature,
Speaker 3: Like exactly the main kind of trash you produce is
Speaker 3: exactly what some other organism in your environment wants as
Speaker 3: a home.
Speaker 2: Yes, though I don't know in this case those as
Speaker 2: we'll look at some of these other examples. Other midden
Speaker 2: producing octopuses do make use of their heap of bones
Speaker 2: and shells, and you know, some of those shells are
Speaker 2: carried away if they happen to be mollis shells, and
Speaker 2: there are hermit crabs in their environment, but they're able
Speaker 2: to do more with them, whereas this particular species Varil's
Speaker 2: two spot octopus, I guess just doesn't have that option
Speaker 2: if most of it's most of it's midden or most
Speaker 2: of what would be its midden are carried away by hermits.
Speaker 3: So one octopus's trash does not ever get to become
Speaker 3: that same octopus as treasure because it was already treasure
Speaker 3: to a decapod that took it.
Speaker 2: Right right, So so yeah, on one level, the octopus
Speaker 2: is midden is yeah, definitely this bone and shell deposit. Again,
Speaker 2: in keeping with our her mythic ideas of dragons layers,
Speaker 2: the cave of Carabanog and so forth, you know, look
Speaker 2: at the bones. And I have to mention that every
Speaker 2: time I've had the opportunity to go snorkeling, I always
Speaker 2: keep a lookout for anything that might be an octopus midden,
Speaker 2: because to observe an octopus in the lie in the
Speaker 2: wild is a most special thing. And the one time
Speaker 2: I really got to observe an octopus out out in
Speaker 2: the wild while snorkeling during daylight, that was one of
Speaker 2: the most magical experiences of my life. It was just amazing.
Speaker 2: But of course octopuses are not always active when we
Speaker 2: snorkelers are out, and even when they are, they are
Speaker 2: masters of disguise in their environments and we're merely humans.
Speaker 2: So I am not good at identifying an octopus as
Speaker 2: midden in the wild.
Speaker 4: You know.
Speaker 2: I'll look at things and be like, that kind of
Speaker 2: looks like it could be a heap of shells, that
Speaker 2: could be some bones. Maybe that is an octopus's midden,
Speaker 2: but you know, nothing ever comes out of it.
Speaker 3: Well, that actually makes me wonder would they make any
Speaker 3: attempt to disguise their middens.
Speaker 2: As far as I know, not intentionally, you know, I
Speaker 2: guess part of the reality is there's you know, things
Speaker 2: are eaten all the time, things are torn apart all
Speaker 2: the time in a marine environment, especially in like a
Speaker 2: really diverse coral environment. So uh yeah, But this is
Speaker 2: I guess, kind of an open question, like are there
Speaker 2: going to be organisms that might identify an octopus as
Speaker 2: midden and therefore try to take advantage of it or
Speaker 2: steer clear of it? I would think not so much,
Speaker 2: because one is, we'll discuss here in a minute. One
Speaker 2: of the key things that the octopus does was with
Speaker 2: the midden is disguise its layer and fortify its layer.
Speaker 4: Okay, that makes sense, And I guess.
Speaker 3: As you alluded to a minute ago, you know, there's
Speaker 3: gonna be a lot of shells and other bones and
Speaker 3: hard parts floating around or settling on the bottom of
Speaker 3: the ocean anyway, So like it wouldn't be unusual to see.
Speaker 4: Those for another organism.
Speaker 3: It's not like it's not like when we see a
Speaker 3: bone pile in a movie.
Speaker 2: Yeah. Now, just because I can't spot an octopus midden
Speaker 2: in the wild or haven't had the luck of spotting one,
Speaker 2: that doesn't mean other humans, actual researchers and experts can't.
Speaker 2: Because it kind of much like the example of the
Speaker 2: cave hyena bone collections we discussed in last episode, Octopus
Speaker 2: middens can actually tell us a lot about what octopus
Speaker 2: species are eating, you know, it gives us a little
Speaker 2: insight into what's on the menu for them, and it
Speaker 2: can also tell us what octopus individuals are eating. And
Speaker 2: this latter point is actually really key.
Speaker 4: Oh you can go through their trash. Yeah, yeah, you.
Speaker 2: Can go through their trash. And it's telling again, not
Speaker 2: just about a species, but also about individuals. As discussed
Speaker 2: in individual prey Choices of Octopuses Are they Generalist or Specialist?
Speaker 2: By Mather at All, published twenty twelve in the journal
Speaker 2: Current Zoology, The question they pose here may have to
Speaker 2: be answered in terms of both species and individual given
Speaker 2: that we're dealing with intelligent and adaptive predators that may
Speaker 2: make their choices based not only on localized prey of availability,
Speaker 2: but also individual personality differences, which I thought was a
Speaker 2: very very interesting consideration. Like, we're dealing with a creature
Speaker 2: that is again highly adaptive, may have a lot to
Speaker 2: choose from in a given environment, and some of its
Speaker 2: choices might not just be part of a basic equation
Speaker 2: of like availability plus ability, and you know the abilities
Speaker 2: of the species, but also like, what does this individual
Speaker 2: like to do? What has it chosen to explore and
Speaker 2: then take advantage.
Speaker 3: Of Octopuses are intelligent enough that they might actually be
Speaker 3: quirky individually quirky.
Speaker 2: Yes, Yeah, another paper I looked two thousand and eighths
Speaker 2: Octopus vulgaris. That's the common octopus, by the way, in
Speaker 2: the Caribbean is a specializing generalist by Anderson at All,
Speaker 2: published in the Marine Ecology Progress series. They looked at
Speaker 2: the remains of six hundred and forty nine prey items
Speaker 2: gathered from the middens of thirty eight dens in a
Speaker 2: small area off the Caribbean island of bon Air, and
Speaker 2: they these middens revealed thirty five species of gastropods it's
Speaker 2: nineteen percent of the total, nineteen bivalves fifty percent, and
Speaker 2: twenty one crustaceans thirty percent. And this particular study argued that, yes,
Speaker 2: the common octopus is a specialized gennalist, with the population
Speaker 2: as a whole boasting a wide choice of prey items,
Speaker 2: but with narrower focus for the individual. So that would
Speaker 2: seem to line up with what this other paper was
Speaker 2: saying as well, But.
Speaker 3: A minute ago you were talking about the actual benefits
Speaker 3: of an octopus as mitten, so that it wasn't just
Speaker 3: a trash heap. It is thought to do something for
Speaker 3: the octopus.
Speaker 4: That's right.
Speaker 2: And then this we can really think of it in
Speaker 2: terms of a dragon or a killer rabbit. So your
Speaker 2: killer rabbit or your dragon is producing all of these bones.
Speaker 2: But imagine that the mythic monster in question here, first
Speaker 2: of all, pushes or blasts all the bones that they
Speaker 2: produce outside of their den. They don't want to sleep
Speaker 2: on all those bones necessarily, And in the octopus's case,
Speaker 2: they can use, you know, their jets to things around.
Speaker 2: So you're accumulating your waist out there in front of
Speaker 2: your den. With the dragon or the rabbit, we're talking
Speaker 2: about a cave, and with the octopus, you know, we're
Speaker 2: talking about some sort of indention in the sand, the
Speaker 2: coral and so forth, you know, the rock, some sort
Speaker 2: of little den they have there with sand and other
Speaker 2: detritus out there already, and then an ever growing pile
Speaker 2: of bones and bits of shell and so forth, and
Speaker 2: so yeah, it's not just a waste disposal byproduct, but
Speaker 2: it's also a source of defense and shelter because the
Speaker 2: heap of shells and bones are then used by the
Speaker 2: octopus to alter the environment. They can use it to
Speaker 2: narrow or even block the entrance to the octopus's den,
Speaker 2: camouflaging it and also fortifying it against incursion. So such
Speaker 2: a den like it provides them a place of refuge,
Speaker 2: but it can also serve a very much more important part,
Speaker 2: like the most important part really in the octopus's life cycle.
Speaker 2: It can serve as the place where a female octopus
Speaker 2: lays her eggs and eventually her final resting place as
Speaker 2: she dies tending to them. So most species of octopus
Speaker 2: only reproduce once in their lifetime, and they enter a
Speaker 2: fatal sinessence phase after laying that clutch of eggs. So
Speaker 2: you know, it's rather interesting. It becomes their home, it
Speaker 2: kind of becomes their tomb, but is also the place
Speaker 2: from which the next phase of the life cycle will emerge.
Speaker 2: And then afterwards, an octopuss den might be reused by
Speaker 2: a new octopus seeking out a place to hold up,
Speaker 2: or of course it could be inhabited by various other
Speaker 2: marine organisms looking for some sort of little place to
Speaker 2: burrow away. But in comparing the octopus is Midden to
Speaker 2: dragons and other fantasy creatures. I think there's an opportunity there,
Speaker 2: And I wonder if any body out there has explored
Speaker 2: this idea, like some sort of dragon that uses its
Speaker 2: bones for some sort of purpose, you know, either fortifying
Speaker 2: its position or I don't know, I guess they're dragons.
Speaker 2: They could potentially do something magical with them, like raise
Speaker 2: all those bones. I imagine there's easily some cases where
Speaker 2: that goes on. But the octopus would argue, no, the
Speaker 2: best thing you can do is create. You end up
Speaker 2: with this big, like sifting pile of bones and sand
Speaker 2: and other materials, and you can just use that as
Speaker 2: kind of like the door to your layer, opening it,
Speaker 2: closing it, partially obscuring and so forth.
Speaker 3: Yeah, so this is kind of similar to the wasp
Speaker 3: and ant example.
Speaker 1: Here.
Speaker 3: Once again it's a case of defensive use of the
Speaker 3: bones or remains of another animal.
Speaker 2: Yeah. Absolutely, Yeah, you know, and in this case that
Speaker 2: these bones are the result of their own consumption, unlike
Speaker 2: the ants. But yeah, they are using them for a
Speaker 2: novel purpose. To come back to your Texas chainsaw massacre example,
Speaker 2: it would be like if the saw your family. We're
Speaker 2: using the bones not only as decorations, but as like
Speaker 2: actual like fences to keep people out, like physical barriers.
Speaker 2: I guess that's the only thing that makes sense. Oh,
Speaker 2: I can't really say environmental disguise, but.
Speaker 3: Well, I was thinking, like, what about lining their driveway
Speaker 3: with bones in a way that like narrows the approach
Speaker 3: of vehicles to the home. You know, you're trying to
Speaker 3: funnel them into a particular area. Yeah, so yeah, you
Speaker 3: said that the octopuses could like narrow you know, or
Speaker 3: control the shape of the opening or the aperture to
Speaker 3: their den with the bones.
Speaker 4: Yeah, yeah, yeah, I could see that.
Speaker 2: Yeah, there's a lot we can learn from the Sawyer clan.
Speaker 2: I think that's what we're saying.
Speaker 3: Putting a bunch of sharp bones out on the road
Speaker 3: in front of the house to puncture the tires of
Speaker 3: trucks that are going by. Yeah yeah, I guess that's
Speaker 3: that's getting away from the octopus example.
Speaker 2: But well, things become increasingly more complicated when you start
Speaker 2: injecting them into the human world. But I think the
Speaker 2: spirit is still there.
Speaker 3: You know, here's a funny thing. Imagine octopuses they developed
Speaker 3: their own technological civilization, their own art, their own genres
Speaker 3: of literature. They discovered that they had a taste for
Speaker 3: horror as well. They liked being scared for fun. Now,
Speaker 3: try to imagine the culture's equivalent of bone imagery, because
Speaker 3: they've only got one hard part, right, it's just the beak,
Speaker 3: So they couldn't have a whole bunch of different bones
Speaker 3: for horror imagery. It would just be beaks.
Speaker 2: I guess you're right.
Speaker 3: Yeah, their pirate flag is just a beak. Every piece
Speaker 3: of skullar bone imagery we have could only be beak.
Speaker 2: That would be their Halloween decoration.
Speaker 4: Yeah, all right? Does that do it for the bone collectors?
Speaker 2: I think it does now. Folks out there, you might
Speaker 2: have some other examples that have come to mind. You're like, hey,
Speaker 2: what about this organism? What about that one? Well, write
Speaker 2: in because we would love to either discuss those on
Speaker 2: future episodes of Listener, may here in the Stuff to
Speaker 2: Blow your Mind podcast feed, or who knows, if we
Speaker 2: get enough recommendations, maybe we have the ammo to do
Speaker 2: a part three, either later this year or next year
Speaker 2: when Halloween rolls around once again.
Speaker 4: Oh yeah.
Speaker 2: In the meantime, we would like to remind everyone out
Speaker 2: there that Stuff to Blow Your Mind is primarily a
Speaker 2: science and culture podcast, with core episodes on Tuesdays and Thursday,
Speaker 2: short form episodes on Wednesdays and on Fridays. We set
Speaker 2: aside most serious concerns to just talk about a weird
Speaker 2: film on Weird House Cinema.
Speaker 3: Huge thanks as always to our excellent audio producer JJ Posway.
Speaker 3: If you would like to get in touch with us
Speaker 3: with feedback on this episode or any other, to send
Speaker 3: us your own example of a bone collecting organism that
Speaker 3: does something interesting with the remains of other animals. If
Speaker 3: you would like to suggest a topic for the future,
Speaker 3: or just to say hello, you can email us at
Speaker 3: contact that's Stuff to Blow your Mind dot com.
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