Ever longed to play a game of catch with an octopus or a chimpanzee? In this classic episode of Stuff to Blow Your Mind, Robert and Joe discuss animal throwing ability. (originally published 01/03/2023)
Hey a you welcome to Stuff to Blow your Mind. My name is Robert Lamb.
And I'm Joe McCormick, and today we are bringing you an episode from the vault. Rob and I are out this week, so we've got some classic episodes for you, or at least classic from last year. This is Animals Throwing Stuff, Part one, the first part of a series we did about throwing behavior and non human animals. We did eventually end up talking about the emergence of throwing as a human behavior as well. This one originally aired on January third, twenty twenty three.
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Enjoy Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Hey you welcome to Stuff to Blow your Mind. My name is Robert Lamb.
And I'm Joe McCormick, and today we're going to be kicking off a series of episodes about examples of throwing in non human animals. We may also talk about the evolution of throwing in humans as well, but this is a subject I recently became interested in, specifically because of a paper that was published in November twenty twenty two. Some of you might have seen science headlines going around about this. There was a publication in the Journal plus one about octopuses throwing objects, or at least potentially throwing objects. Whether or not it should count as debatable, and we'll talk about some of the arguments for and against. But octopuses at least allegedly throwing objects, potentially deliberately, and potentially deliberately aiming those objects at other octopuses, though of course, the exact nature of their motivations is somewhat mysterious. It's hard to suss out exactly. And I thought it would be good to to start off our series by looking at this example that first got me interested in this, and then maybe we can branch out to other examples of throwing in the animal world in subsequent episodes.
Interesting, I just assumed that your interest in this topic was because you had become a father and you were already feeling the pull. You already were longing to throw ball with your child, which is something that I felt when I became a father. I was like, well, I've got to get a ball, right, I've got to get a mit. I have no other connection to baseball at all, or softball or any of these sports, no attachment to them. I don't play them or watch them. But there's something about throwing that must be done with the child.
I do like throwing a ball. I think I'm more into like a tennis ball in the hand than a baseball.
But that's a dog thing, that's for dogs. I guess that's true.
Also, No, I'm not talking about with like the scoop, I mean the rollerball scoop. I mean tennis ball straight in the hand. Okay, all right, but no, that's not the reason. And if I were to go with the motor activities I've been thinking of more since becoming a father, would be the act of knocking things over after they've been set up. I think that's an interesting impulse that we could study.
Oh yes, definitely.
But onto the octopus study. So this paper was by Peter Godfrey Smith, David Shiel, Stephanie Chancellor, Stefan Linquist, and Matthew Lawrence, and it was called in the Line of Fire Debris Throwing by Wild Octopuses, published published in Plus one, twenty twenty two. And so first I'm going to talk about what the authors report and argue in this paper here, and then we'll talk about some context as well as some criticism or differences in interpretation. Now, for background on this subject, I think we can safely say that not a lot of animals throw things at all. Throwing is a relatively unique behavior, and the authors of this study say, quote a throw can be distinguished from other phenomena by the ballistic motion of a manipulable object or material, where ballistic describes free motion and momentum. So when I think of throwing, I think of taking a free external object or material, so not part of your own body, and projecting it through the environment toward a target. Throwing is so unique that it has sometimes been characterized as exclusively the domain of humans. But there are a number of animal behaviors that I think should count as throwing. We'll talk about them throughout the series. Some very clear examples that I don't think anybody would really dispute, like the throwing behaviors of primates like chimpanzees and capuchin monkeys.
Right right, Yeah, there are plenty of examples of this occurring both in the wild and in captive. Not to say they're not interested. We may come back to some of them, but yeah, they're very well documented.
Yeah, and also some very interesting ones in like elephants and mongooses and birds and so forth. Yeah, Now, if you were to expand the definition of throwing to include the projection of parts of the animal's own body or substances produced by the animal's own body, then the number of examples really expands. Then you get all kinds of things, Like you get spitting, which would include snakes. There's snakes that project venom out of their mouths, out of their glands. You have, of course, camels famously spit. All kinds of animals spit. And then you also have examples like spiders such as New World tarantulas. These spiders famously kind of kick or shoot a little fibers known as irticating hairs off of their bodies, and these are a defense mechanism because the hairs can cause severe irritation to the skin and mucous membranes of vertebrate animals that might threaten the spiders. And you know, I've always thought of this in the context of like tarantula itching powder, Like it's just an irritant, it's unpleasant, it gets on your skin, it causes itching, makes you want to retreat. But apparently in some cases of like the tarantulas, with more severe hairs. This can even cause death in the cases of some small animals when the hairs get in their mucous membranes.
Tarantulas are fascinating. I'd be up for a return to the world of tarantulas again.
But there are other spider examples too. Some other spiders are known to project or throw threads of silk produced again by their own bodies at prey to capture them. But I think we probably don't want to count substances produced by an animal's own body for throwing, because that seems like a kind of that's a different class of behavior than what we usually think about with throwing, because when it comes out of the animal's own body, I would think that usually tends to be an instinctual, defensive or predation mechanism. That's something that's probably just a rote behavioral program that exists. You know, it's evolutionarily coded into the animal's nervous system, so they just kind of do it automatically. Whereas the throwing of free external objects found in the nearby environment, I would argue that indicates a very different kind of underlying mentality, a much more interesting and versatile type of tool use.
Well. Of course, it's easy for us to say since our bodies don't really produce weapons. It might be a different scenario if human beings, say, produced and shed some form of horn or antler, or I don't know, had had some other you know, let your imagination go wild. But one might well imagine some sort of a humanoid being that had some sort of evolved feature like this. That might blur the line. But I do agree, Yeah, certainly, with the human factor involved, humans are not really going to do much with anything that their own body produces. They're going to have to turn to the things in the environment around them.
Yeah, it would be interesting if a human could like cough up darts from their stomach on command. Now what now, I'm trying to think how to make that plausible. Okay, Now, imagine you've got an animal that has a sort of gizzard and they keep gizzard stones down there, and when they need a weapon, they just vomit up a gizzard stone and then they can throw that there.
You go, surely somebody's had done something like that. Would that would be terrific. You have some sort of like a kaiju bird and one of its attacks is vomiting stones at you and these stones could perhaps you know, be used as some sort of a siege weapon.
Okay, so that's the distinction between like an instinctual throwing or projecting of part of your body or something that comes out of your body versus throwing of things found in the environment. Another distinction I would like to make about throwing is the important difference between throwing away and throwing at. For one example of this contained within one animal, I think you could possibly make the argument that the ant lion might exhibit both types of throwing, because it certainly at least does one. So the ant lion, at one stage in its life cycle, it lives down at the bottom of a pit that has steep sloped sides with the sides are lined with sediment of a certain grain size, and a prey insect falls in it can't climb back out, and then the ant lion kicks sediment or sand up at the insect, and the insect falls down into its jaws and it eats them. And then after it's done, it is typically known to fling the body out of the pit by a similar motion to what it used to fling the sand up at the insect falling in now, I think you could definitely make the case that it shows throwing away behavior because it's just rejecting the desiccated exoskeleton of the ant that it has drained of delicious juices once it's done right. Yeah, absolutely, But it may also display throwing at behavior, arguably because as the ant is falling down, it will kick sand up at the ant, and you could argue about whether that's actually at the ant or whether it's just kind of generic sand throwing behavior that because the real purpose, I think is not for it to land on the ant, but to destabilize the walls of the pit and cause them to avalanche downward, bringing the ant further toward the bottom with the sand.
Yeah. I believe we talked about the ant line a bit in our episode on the Sarlac, comparing the sarlacs imagined biology to the ant lion's very real biology, and yeah, they're fascinating little creatures.
But the authors of this paper all so mentioned in the background how in some cases throwing is a kind of tool use that also sort of contains information. Like a projectile can be not only aggressive and violent, but it can be a communicative social tool between animals within a social species, and that brings us to the example of the octopuses, because one thing it's really important to realize about octopuses is that they are, for the most part, not social. They are incredibly antisocial as far as animals go. With perhaps a few notable exceptions, octopuses generally do not socialize with other octopuses. They don't flock together, they don't form groups usually or have very complex social relationships. For the most part, octopuses are solitary hunters, and when they do encounter one another, they practice avoidance or sometimes outright violence. They will fight one another and sometimes even cannibal one another.
Yeah, that seems to be the extent of octopus politics.
However, despite their usual antisocial nature, there is some previous evidence that octopuses might be able to communicate with or signal information to one another, and an example that the author's pick here is one that has some of the same authors as this study in question. It's by David Shield, Peter Godfrey Smith, and Matthew Lawrence, called Signal Use by Octopuses in Agonistic Interactions, published in Current Biology in twenty sixteen, and this study looked at the same species as our main study is going to be looking at here one called Octopus tetricus, and this species can change color pigment. It can change the color patterns on its skin in a number of ways. And this report found a correlation between color displays on this octopus's skin and intraspecific behaviors, behaviors showing interactions between members of this species. The authors write, quote, here we show by field observation that in a shallow water octopus Octopus tetricus, a range of visible displays are produced during agonistic interactions, and these displays correlate with the outcome of those interactions. Interactions in which dark body color by an approaching octopus was matched by similar color in the reacting octopus were more likely to escalate to grappling darkness, and an approaching octopus met by paler color in the reacting octopus accompanied retreat of the paler octopus. So this is interesting. It raises the possibility that even though these octopuses are not very friendly with one another and they don't really want to hang out and interact, they might still be communicating. They might be using color displays to at least communicate information about their intentions with one another, and that could be beneficial to both parties because it could help them avoid unnecessary violent cons Like if you can change your color patterns to signal like I mean business, I'm not going to back down, or okay, okay, I'm not going to fight like that can help you avoid a fight that would have happened otherwise.
Yes, yes, this is of course a topic that's come up recently on the show. In a couple other episodes, we talked about the Galapagos tortoise, about the showdowns between these big males and how it is almost, if not exclusively, non violent in that they just have these showdowns with their neck who's the tallest, and whoever is the judge would be the tallest wins, and there's no need for actual violence to take place. It also reminds me of the episode I did with Joe Berger while you were out talking about goats and rams getting into conflict over mineral resources, and part of the issue there it does come down to how goats deal with this sort of conflict between each other, how rams deal with this sort of conflict with the each other. But then when you have goats and rams, there can be kind of a communication breakdown. It's really interesting.
Yeah, well, I mean it makes you think about how much apparent conflict and violence within the natural world actually doesn't come to violence because animals are often looking for a way to avoid a fight. They just want to know who would win and like find a way to sort it out without having to do the violence.
Yeah. Even in a lot of human combat, whether you're dealing with individual level or more complex scenarios involving civilizations and so forth. You know, there's so many different ways. There's a lot of posturing. But then there are also the fights or battles one might get into with the intention of being stopped by others before the battle can take place. Like, there's so many different things to consider though.
I also want to come back to this example I mentioned about the changing color patterns on these octopuses. I think you could also have non communicative interpretations of this as well. That's possible, but it's one good interpretation of that might be that these animals are communicating with each other, they're sharing information, even though they're not really a social species. Now, we also know that octopuses are able to manipulate objects in their environments using the surprisingly deft touch of the eight octopus arms, raising the specter always of possible tool using intelligence and even maybe one day technological evolution in the octopus. And we've seen many great examples of this. One that I always think of is in octopus nest building behavior. Sometimes you'll find examples where an octopus will be able to pull an object over the opening of its den in order to essentially close the door, which I love. But also this study mentions veined octopuses or anti octopus marginatus, which they say, quote Carrie can carry shelter in the form of nested coconut shell halves that are then reassembled. You may have seen video of this.
Yeah, this is this is remarkable footage, and I know just the just look watching an octopus in the wild or in captivity. It seems to have inspired many to imagine what it would be like if they actually use tools and weapons. I was trying to remember where I had specifically seen an image of an octopus with like a hatchet in one of its tentacles. I imagine this was maybe an old Dungeons and Dragons illustration or something. But I did an image search and I found that numerous people have have painted some sort of a scenario in which an octopus is carrying a spear. I saw one where there's like a spear wielding octopus battling a samurai octopus. So there is something about the octopus arms that we can't help but imagine them doing tully or weapony things with them.
Not sure exactly why, but that reminds me of the doomba meme where people would just like tape a knife to the top of their roomba.
I don't know if I saw that one, but sounds dangerous.
Okay, Well, anyway, these two different threads we've been talking about the use of materials or arguably tools from the environment by octopuses and behavior that might constitute social signaling between conspecifics. These two things come together in this twenty twenty two study. So the animal in question in this paper is the species Octopus tetricus, also known as the gloomy octopus. Now why are they called the gloomy octopus? Well, just look at their eyes. Some people think that these animals have eyes that look perennially unhappy. I don't know what I think about that. It's hard to it's hard to read too much human emotion into octopus eyes. But then again, I get to staring at this and I don't know, maybe I do feel kind of the mood coming down a little bit.
I don't know. Maybe I mean I get kind of a calm vibe off of this particular octopus. It looks cozy.
Well, they do like to be cozy. They like to hide in their dens. So, the gloomy octopus is a medium sized benthic octopus. Benthic meaning they live on the seafloor and they occupy the waters around Australia and New Zealand. But the particular population of animals observed in this study live in a special zone along the bottom of Jervis Bay, Australia, which is the coast of New South Wales at south of Sydney. And in this area along the bottom of Jervis Bay, many individuals of the gloomy octopus live in very close proximity to one another, high density, especially four octopuses, making dens sometimes just right smack next to one another. Now, is this a change? And they're normally solitary anti so nature, it does not seem like that. There's no indication that these animals like being near one another. Instead, it's a case of a lot of octopuses trying to cram into a spot that has both food abundance and excellent benthic strata for making dens. So it's good real estate to make homes in, and it's lots of great food, and it's surrounded on all sides by terrible real estate, just sort of featureless mudflats, which sort of prevents these octopuses from spreading out. So for a human analogy, imagine a kind of tiny island in the middle of the ocean with tons of food on it, lots of great stuff there, but it's just swarming with antisocial introverts who don't want to talk to each other.
I think I've had this experience on most road trips I've taken. You know, you find that one exit that has that one chain coffee store that you need and can depend on. And yeah, an alien observing you might say, look at all these people. They all love each Yes, they love being around each other. Oh that's good.
So these spots in Jervis Bay have been nicknamed things like Octolantis or Octopolis. Just a lot of these anti social non buddies squeezing into a relatively small area. Naturally there's going to be some conflict here. The octopuses regularly get in one another's space, and this leads to the creatures poking and grappling, grabbing, generally harassing each other. Now, it was in studying this Jervis Bay population of Tetricus that the authors first observed what they called a throwing behavior. And the team collected many hours of video footage from emplaced cameras from a couple of different sessions. I think there was some footage from twenty fifteen and from twenty sixteen, and they write, quote, here we provide the first report for any octopus species of a behavior freaque at these aggregations. The throwing or projection of debris, both in social interactions and in other contexts. Ballistic motion of manipulable objects is possible through water, albeit against greater resistance than through air. These throws by Octopus tetricus sometimes hit other octopuses. So they are throwing debris, sometimes hitting other octopuses. And the big question is are they doing it on purpose? Are they targeting one another on purpose? And if they are, is that a social signal of some kind?
Now?
I think it's important to first just describe exactly what's going on here. When an octopus is said to quote, throw something, Octopuses do not throw the way humans do by building momentum with an arm motion and then releasing, or at least not most of the time. The team apparently documented one case of an octopus throwing what looked to be a bivalve shell by holding it in its arm, quickly straightening the arm, and then releasing the shell. Instead, what happens is most of the time the octopus would throw by way of its siphon, and the siphon, also called a funnel, is kind of a tube shaped organ that octopuses used to swim. You can think of it as an organic water jet. It's sort of a pump that pumps water out the back and allows the octopus to to by reaction, push its body forward.
Interesting, so in these in these cases of an octopus throwing, depending on what is being thrown, you could think of it as being like they've loaded their their biocannon, their their fluid based biocanon with like say, a piece of shell and are firing it. Or it's just kind of like loaded with debris.
Yet well sort of I mean that is good, I think, except actually what the cannon is loaded with is just water as usual. It's more like they've loaded a cannon and they have put the thing they want to throw right in front of the cannon, so that when the cannonball comes out, it hits the thing they want to throw, the cannonball just being water and propels it toward the target. Again, assuming that these are targeted throws. We don't know that for sure, but going with that for a minute. So it's a several step procedure. It goes like this. So this octopus, Octopus tetricus, it will gather external material. And there were three main types of material that the authors observed being thrown in the study. One is shells, generally mollusk shells, though like scallop shells, which also would be the shells of things that the octopuses are eating. And then the other one is algae and then finally silt or sediment from the sea floor, so just you know, mup sand, that kind of stuff.
This sounds like dirty Fighters. It sounds like the scene in so many movies, especially like Sword and Sandal movies, where there's some sort of a gladiatorial combat going on, and what does the villain do. Oh, he's going to get a little sand off the battleground floor throw it in the eyes.
Of Except the gloomy octopuses are all dirty fighters. They love to shoot this silt, so you scoop that up in your arm, So they're actually using their arms for this part, scooping up the thing whatever it is, shells, algae, or silt, and then they hold it underneath the body. They hold it underneath the body with your arms, and then they position their siphon underneath the body, which is not normally where it is. They kind of hook it under so that it lines up behind this stuff, and then they release the stuff with their arms at the same time that they blast it with a jet of water from the siphon, and then that jet of water carries the sediment toward its target. So again, this is very different than human throwing. I think for a rough analogy, you'd have to imagine that you could throw a baseball not by extending your arm rapidly and releasing it, but by like holding the baseball in front of your face and then suddenly releasing it from your hand and at the same time blowing on it really hard to shoot it off where you want it to go, and of course in order to do this we need to have far more lung capacity and diaphragm power than humans actually do have. But just imagine you could briefly create like a little jet engine exhaust port with your mouth. And this is interesting because it reminds me of stories I've read elsewhere of octopuses using directed siphon jets, but without any material being propelled other than the water itself, Like the main thing is something of their stories of octopuses in captivity squirting their handlers with water from their siphon, often in the context of the handler believing at least that the octopus is annoyed with them or being defensive.
And of course this is also reminiscent of squid using their ink in various ways, though of course that would would obviously be an example again of an animal using something created by its own rather than in this case, using something from their environment.
Right exactly so, when the researchers watch the gloomy octopus do this throwing of shells, weeds, and silt, some of the instances were obviously cases of simple rejection behavior. The throwing away. We talked about it earlier, and a great example of this would be what they classified as eating based throwing behavior. So sometimes the octopus is going to eat, you know, a bivalve or something. Maybe it eats a scallop, and then it throws the shells away. When it's done, it actually projects them away from the body. Other examples of throwing away behavior would be the classification they call den cleaning. The octopuses actually do tidy up their dens. So they're going to try to make a little heidi hole to settle into on the seafloor, and sometimes I guess it gets dirty in there, so they want to basically blast a bunch of stuff out of there. And so they will do this with their dens to get things out of the hole.
Yeah, you don't want your midden to get out of control there with the bones of your many kills or the shells of your many kills.
Other times they showed apparent throwing behavior that the researcher said was anomalist. There was no apparent reason. Maybe an octopus is just kind of like rippling along. Nothing's really going on. It's not eating, it's not in its den, nothing else is around, but it just kind of throws something that didn't happen a lot, but occasionally it did. And then finally, the last category they said was what they called interactive throwing. This is when the octopus was interacting with another octopus or in a few cases, another animal or object such as a fish or a camera. And these are the ones that are really interesting because in this case, the researcher said, it really looks like not just throwing away behavior, but throwing at behavior. It looks like the octopuses are intentionally throwing things to try to hit or discourage other octopuses in their vicinity. So what proportion of throws are represented by these different categories. Well, to read from their results, quote, over half of all throws, or fifty three percent, occurred in interactive contexts, thirty six percent in interactive, only seventeen percent in interactive mixed. And that's where they're interacting with another octopus, but also something else is going on, like maybe they also just finished sheeting, or they're also cleaning out their den. Thirty two percent occurred during den cleaning, only eight percent after eating, and eight percent without a parent context. Oh, and this total is more than one hundred percent due to rounding, but they say that the material throw so. And then there's another distinction they make throw interactive throwing, where they're basically interacting with another octopus and they throw in that octopus's direction, and then they make the distinction of, well, did the stuff they threw actually hit the other octa to pus on the footage they captured, and they said that the material throne hit another octopus in seventeen cases that they documented. In two other throws the material hit a fish and so. Co author David Shiel said speaking to the media, it seems like there's a target and they're not throwing away, they're throwing at But it is a difficult question, like how can you prove that they are actually intending to hit another octopus with this stuff when they do it. Of course, it's possible they're just accidentally or maybe inconsiderately hitting one another with these waterjet payloads while they're doing something else. Maybe we don't know why they're doing it, and the researchers aren't sure that these throws are intentionally targeted, but they argue that on balance, that is the more likely interpretation, and that it possibly is some kind of social signal, and they give a few arguments why they think it is the more likely interpretation. So, for one thing, you might imagine that interactive throws are targeted and social if you notice some patterns, like patterns of differences between interactive throws versus other types of throws. And the researchers did, in fact document some differences specifically between throws that hit another octopus and throws that did not. One difference was which arms are the octopus using. I thought this was really interesting because it wasn't exactly what I would have expected. But here's what they say. Okay, they say a total of fourteen throws out of ninety eight that could be assessed as anomalous arm throws, and these would be throws using one of the side arms instead of just the two front arms. They say, quote, anomalous arm throws were more likely to hit other octopuses than L one R one throws, and L one and R one are the two frontal arms. So it seems like if you're just cleaning out your den, there just kind of throwing stuff wherever you use the front two arms, but way more often if an octopus throws something and it hits a different octopus, they're using their side arms. Isn't that kind of strange?
Hm?
And they found that the side arm throws were less common overall, but more common if the material hit another octopus. So something about this pattern of arm choice could indicate maybe a type of aiming behavior with hostile intentions. It's hard to know for sure, but that is an interesting difference. They also write quote in three cases of hits, a thrower also altered their body orientation towards another octopus, but these movements were very slight, and the effects of arm choice other than L one R one were more marked. Okay, so that's one difference between throws that hit other octopuses and throws that down't. Second difference body patterns and throw vicar. These octopuses, as we mentioned earlier, can change their external appearance, and in fact, they might even change their external appearance in order to signal to other octopuses, maybe to help avoid aggressive encounters. And remember before, when an octopus displayed a uniform dark coloration, that was usually a sign that they were displaying kind of like dominant aggressive behavior, whereas maybe like turning paler might indicate that they were willing to back away from a fight. The authors here found that throws that hit another octopus more often took place when the thrower was displaying a uniform and especially uniform dark body color.
Quote.
We noted that throws by octopuses displaying uniform body patterns, especially uniform dark patterns, were more often thrown with high vigor. Further, throws by octopuses displaying uniform body patterns also hit other octopuses significantly more more often than those in other body patterns. And then also they say, in addition, high vigor throws more frequently hit another octopus. However, with that last point, they want to clarify, and I think this is good to point out. High vigor throws, of course, are because they're higher vigor, meaning thrown harder, They go longer, and they have a wider range, which could explain more frequent hits even if they're not deliberately targeting somebody. Like a random throw that goes farther and spreads farther is more likely to hit something randomly than one that doesn't. Another thing they noticed material chosen. When octopuses through something that hit another octopus, it was way more likely to be silt as opposed to the other materials, which appeared more often in other context. So maybe an octopus is eating or cleaning its din, it's going to be more likely to throw shells around. When an octopus gets gets into an aggressive interaction with another octopus, it seems more likely they will throw silt at them. Back to the dirty fighter point.
Yeah, yeah, And there's something about, you know, the throwing of the silt too that that I don't know a lot of this is just the human perspective and all, but I know it makes me think of of things like another trope from films, throwing a single pebble at a at a window pane to get somebody's attention. Oh yeah, you know, like you know where it's You know clearly you're not you're actually trying to harm anyone, but you want to. You're creating a message. You're you're you're sending a signal, and in a different way. Uh, there is a difference between pelting somebody with sand and throwing a rock at them. Like even in the human scenario, these are two These are two acts with rather different messages. If they were to happen, say at a beach between two people.
Yes, that that's correct, So I think the material may make a difference there, though they did say that the difference that they found in material choice was not statistically significant because they're dealing with the small number of samples here. There was a difference in the numbers, but it didn't make statistical cut. Now. One thing, they did also observe repeat offenders and aggressive patterns. They say some particular octopuses would repeatedly throw and strike another one again and again and again, and this kind of repeated hit behavior would seem to indicate a deliberate, targeted pattern more than an accidental one. The authors also say quote hits in many cases occurred within sequences of interactions that featured ongoing mild aggression, including arm probes and momentary grappling. So they're saying we saw throws that hit another octopus often win octopuses had already been tussling.
A lot, okay, and another way of stating it, some octopuses might just be jerks.
One last thing, they say there were defensive behaviors. The apparent victim of the throw often reacted by either holding arms up to block the of material flying their way, or by ducking and dodging out of the way, And they said sometimes octopuses who had been hit altered their behavior in some other way by say, like pausing or halting or redirecting their movements. And this last point I think is really important because the authors say, you know, even if these throws are not actually socially intended, they do appear to have social effects, Like if they cause redirected movement in the victim, that would seem to be a socially relevant behavior. Even if you would I don't know exactly what it would mean in this case though, to say that they were not intended to be social signals by the by the individual throwing.
Yeah, it's so, I mean, it's it's an impossible task to try and do, to try and like put yourself in the mind of an octopus, but you can't help. But wonder, coming back to some of what you said earlier, like, is it potentially indeed like a directed action where the octopus, in it's own own octopus way, is quote unquote thinking I don't like you, I want you to go away, or something I will throw sand at you. Or is it like the octopus is throwing sand while having a certain hostility towards other octopuses or a particular octopus, and in doing so, these things kind of aligne and maybe there's less intention there. I don't know.
Oh no, I think that's a really good point, and that comes up in one of I think the better criticisms of the study that I want to get to in just a minute. But just before I do that, I want to mention a few other things that the authors highlight several things they did not see, and I think it's worth paying attention to what these are. They say, you know what, we never saw an octopus quote return fire, So they never saw a throw hit initiate any kind of violent retaliation by the target. That they did see the targets like it might make them sort of go away or redirect their movements. They also say, and I thought this was quite interesting, quote some throws in what appear to be fairly intense interactions were not directed at another octopus but into empty space. So octopuses might be tussling pretty strongly, like they're fighting each other, but then in the middle of that, you know, prolonged aggressive interaction, the octopus just kind of like throws some material, but not at another octopus just throws something. It almost invites comparisons of just like throwing things in a huff. But I don't know if you could say that's what's going on with an octopus.
Yeah, yeah, no, you can't help but think that again putting the human lens over everything.
But anyway to come back with some criticisms of this type of interpretation, I was reading an article in the Atlantic by Marina called everyone has an Octopus Opinion, And this article collects some arguments that there might be less than meets the eye when it comes to the octopus throwing footage and saying that the interpretation of socially targeted throwing might just simple simply be anthropomorphization. So a few things that are collected in this article. One is that corn documents a dissenting opinion from an evolutionary biologist at San Francisco State University named Robin Crook, who questioned whether this behavior really counts as quote throwing because of the physical processes involved, noting, again, like we talked about earlier, that while octopuses will grasp things and pass them around with their arms, they don't use their arms to throw the way we do. Instead, they use this siphon blasting maneuver, which to Crook does not constitute throwing. I don't know if I would really like make this distinction. It seems to me like the important part of throwing is like the intentional ballistic projection behavior of objects from the environment, not so much like the muscle movements you use to do that. But I don't know what you think.
Yeah, I mean a lot of it's just going to come down to body type, right, and what kind of tools you have to send stuff fly in at another creature. Really, I keep coming back to children and all of this. I can't can't wait for you to take everything in this episode with you when you start taking your child to the beach, because yeah, a human child is certainly an education in all the ways that you can You can send sand flying in the wrong directions as well as various other objects. They can kick it, they can throw it, they can shake it from the towels. It's wonderful.
I have so much magic of that kind of look forward to. But no so so, Crook says. Another thing is that you know, like we were talking about, there, there are other contexts in which octopuses clearly show this kind of like siphon blasting behavior such as cleaning up their dens after a big meal, you know, blasting a bunch of mollusk shells out, and Kirk argues that maybe that's all that's happening in the footage that's examined in this paper. Sometimes they're just blasting their dens out or doing a behavior that they do when they blast their dens out and hitting other octopuses by accident. In the total footage, this article claims that only seventeen percent of the throws actually hit another octopus, So a majority of what we see either way is just throwing away behavior, not throwing at. The question is whether this minority of cases where it was interactive throwing, and especially the ones where it looks like interactive throwing and it actually hit the other animal, those are the minority we're looking at. That's just seventeen percent of all the throws.
Yeah, I mean, I again come back to something you mentioned earlier about again, the octopus is generally a solitary creature, and this is a scenario in which they are living in close proximity to one another due to the restraints of the environment itself. So you could just simply look at it, like, look, these octopuses are violent slobs, and normally they're on their own being violent slabs, but now they're forced to live together, and this is what happens when octopuses, I don't know, stop being polite and start getting real.
Now, there are several things raised in this article, but one I thought was actually a pretty good point to make was that even if the octopuses are trying to hit one another with the throwing, so maybe you can say, like half of the equation is true. Maybe it is targeted throwing. They are throwing at the other octopus. But at the same time you could say it might still not be social octopus signaling exactly because in the words of Piero Amodio, a biologist who has specialized in octopuses Aton Dorn Zoological Station in Italy, it may be quote used more broadly towards annoying or threatening stimuli. So maybe it's not a thing about octopuses communicating with octopuses, but it's just like something is bothering them, so they throw they just squirt object, they squirt material at it. And evidence for this would include octopuses were also observed in a couple of instances in the study throwing debris at fish and at a camera emplacement in a couple of cases, so it could be less intraspecific social signaling and more like, I don't know what that is, I don't like that object in my space. Just squirt some dirt at it for this objection, I think fair enough. Like in that case, I think it would definitely count as directed throwing. It would be throwing at rather than throwing away. But this might limit what kinds of interpretations we could make about the relationships between gloomy octopuses specifically. The article makes cites one line argument that I thought was pretty interesting, and this comes from Christian Nauroth, who is a researcher on the behavior of goats at the Research Institute for Farm Animal Biology in Germany. And the point that Naarrath makes here talking about goats is that, yeah, even goats have lots of mysteries about them. Quote, they sneeze when they're spooked or frustrated, and there is actually nothing on how often goats show this behavior, how often they use it in which contexts they use it. And I thought that was really interesting because it, of course is especially hard to figure out the motivation for animal behavior when you're studying them in the wild as opposed to in the lab. Like in the lab, you can strictly limit variables to some degree, but in the natural environment there might be thousands of variables to disentangle, and you might not even recognize what some of them are. And the specific example about Okay, so goats sometimes sneeze when they're spooked, but like, why do they do that? What exactly are they trying to do with the sneezing. Is it a directed behavior or just a kind of tick or what? It reminds me of our recent discussion on the Galapagos marine iguana. Do they sort snort salt out of their salt glands at an attacker defensively, like when something is approaching them, when a Charles Darwin is approaching them, as Charles Darwin thought he observed. Or is the salt snorting not actually correlated with defensive behavior? Is it not actually motivated by defensive considerations at all? It's hard to tell.
Yeah. Again, it is so hard to step outside of the of the human lens here when trying to imagine what any of these creatures are doing. Because some of these things like we want to interpret them and think about them as being deliberate actions as opposed to, say, in the human scenario, sort of incidental signalings of hostility that we might have, Like someone can look hostile on say a bus, without actively thinking like, oh, I'm going to show everybody on this bus how I feel about them. Check out my hostility. Don't come near me or violence happens next, like you could. That person could just genuinely be and say a bad mood or be thinking about something that's bothering them, and their their posture, the way they their look, their expression on their face could take on a hostile energy that would then be picked up on by other people.
And that and that kind of ambiguity exists even within our very finely tuned ability to suss out the motivations of other humans. These are cron specifics. We're right in that human meal you you know, we're used to that when looking at another species. I mean, it's like several orders of magnitude more difficult to figure things out.
Right, right, Because again, that same dude on the bus that you're thinking looks hostile, he could just be thinking about a really cool episode of some TV show that he watched, you know, and that's just all you because you think, oh, somebody who looks weird on a bus must have hostile intentions. They must have something negative going on, and they don't just have an intense look because they're trying to figure out the plot of I don't know, some Netflix show.
Now, I think when it comes to the ambiguity behind animal behaviors, there might be other kinds of considerations that would come in, Like, Okay, is the marine iguana even if you could show, wow, it does you know, snort salt out of its salt glands more often when a human is approaching it, That would show a correlation with the proximity of a larger land animal. But it wouldn't. It wouldn't still wouldn't show it was defensive in some way. I mean, maybe it's snorting like that because it's trying to I don't know, like clear some kind of gland blockage in case it needs to move quickly or something like that. Maybe that's part of the kind of fight or flight physiological internal regulation of the iguana's body. Who knows, I'm just speculating there, But you could imagine other things for this octopus throwing behavior. Maybe the throwing is part of something that's going on internally with the octopus that is related to aggressive interactions with other octopuses, but is not about hitting them with the objects, though it's hard to figure out what that other purpose would be. Then again, maybe it is just about hitting them with the salt. I mean, that seems like a perfectly plausible explanation to me.
Either way. A fascinating look here, another fascinating consideration of the world of the octopus. And this episode is also kind of a stealth goat episode too, since we got to get in a little bit of goat pondering here at the end.
I like that. But we're going to be back with more interesting examples of throwing behavior and animals, so these questions will continue.
That's right, so be sure to join us for the next one. Let's just remind everybody that's Stuff to Blow Your Mind. It publishes in the Stuff to Blow Your Mind podcast feed with our core episodes on Tuesdays and Thursdays. On Wednesdays we do a short form artifact or monster fact episode. On Mondays we do listener mail, and on Fridays we set aside most serious concerns to just talk about a weird film.
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