Speaker 1: Welcome to Creature Feature production of iHeartRadio. I'm your host
Speaker 1: of Mini Parasites, Katie Golden. I studied psychology and evolutionary biology,
Speaker 1: and today on the show it's a listener questions episode.
Speaker 1: I take your questions about animals, about animal behavior, about
Speaker 1: evolutionary biology, and sometimes about people, and I try to
Speaker 1: answer them to the best of my ability.
Speaker 2: So let's get right into it. Here's the first listener question.
Speaker 2: Oh by the way, if you have one that you're
Speaker 2: dying to ask me and you don't know how to
Speaker 2: do it, well, it's easy. You write to me at
Speaker 2: Creature featurepot at gmail dot com and I do my
Speaker 2: best to answer all the questions I get either by
Speaker 2: email or right here on the show. So here is
Speaker 2: the first question. Hi, Katie, longtime listener. I just came
Speaker 2: across this quote cute video. My first thoughts are that
Speaker 2: something is wrong with the shark. Can you tell by
Speaker 2: watching if this is normal or not? Thank you Danny J.
Speaker 2: So the video that Danny sent me is a shark
Speaker 2: approaching a boat with a diving cage, and instead of
Speaker 2: eating everyone on board, it backstrokes and swims with its
Speaker 2: belly up. It kind of swims back, makes a half
Speaker 2: hearted attempt at biting part of the boat, and then
Speaker 2: swims away. So this looks like a great white shark
Speaker 2: to me in the video, it is unusual behavior actually,
Speaker 2: because sharks do not typically swim on their backs. In fact,
Speaker 2: being upside down isn't a great position for the shark
Speaker 2: to be in because this can trigger a state called
Speaker 2: tonic immobility. My guess is that the shark got a
Speaker 2: little disoriented by the diving cage that it sort of
Speaker 2: bonked into and accidentally swam itself upside down, So that
Speaker 2: would be my guess. I think the shark made a
Speaker 2: bit of a clumsy kind of like meet cute clumsy girl.
Speaker 2: Move here. But I don't think it's like sick or anything.
Speaker 2: But let's talk a little bit about tonic immobility and
Speaker 2: why it happens when sharks are flipped over. So sharks
Speaker 2: and rays experience tonic immobility when they are flipped on
Speaker 2: their backs and held there. It's so effective in some
Speaker 2: species of sharks and rays that researchers can exploit it
Speaker 2: to examine sharks or to outfit them with trackers. Sometimes
Speaker 2: it's used instead of anesthesia because it's so effective. So
Speaker 2: while the shark is experiencing tonic immobility, the shark's breathing
Speaker 2: will slow down and they will be in a kind
Speaker 2: of catatonic state until they are released entered right side up.
Speaker 2: Orcas will sometimes use this to attack sharks. Actually, so
Speaker 2: orcas will slam into sharks and when the sharks flip over,
Speaker 2: the orcas will kind of try to restrain them and
Speaker 2: either attack the shark or wait for the shark to
Speaker 2: drown before having a shark snack. And orcas will do this,
Speaker 2: especially to great white sharks. I now what we think
Speaker 2: of great white sharks as like the apex predators, they
Speaker 2: don't have anything to fear. Well, orcas are kind of
Speaker 2: buttholes and they will definitely attack great white sharks who
Speaker 2: are just vibing. So why how would a great white
Speaker 2: shark drown underwater? It's a fish that doesn't make any sense. Well,
Speaker 2: great white sharks are what are called obligate ram ventilators,
Speaker 2: meaning that in order for their gills to process the
Speaker 2: oxygen from seawater, the shark has to be moving to
Speaker 2: maintain the flow of water. So not all sharks are
Speaker 2: obligate raum ventilators. So it's not true that all sharks
Speaker 2: have to keep moving to stay alive. In fact, the
Speaker 2: majority of species of sharks do not. They actually have
Speaker 2: something that they have a buckle pump of pump in
Speaker 2: their cheeks that maintains the flow of water over their
Speaker 2: gills even when not moving. But there are some species
Speaker 2: of sharks that are ram ventilators. They have to move
Speaker 2: or at least have some kind of flow of water
Speaker 2: in order for their gills to work, and so great
Speaker 2: white sharks are one of these species. So if they
Speaker 2: are held in a state of tonic immobility for too long,
Speaker 2: they'll actually suffocate because they aren't getting that flow of
Speaker 2: water over their gills and they are asphyxiating. So another
Speaker 2: way in which tonic immobility can be induced in is
Speaker 2: by overstimulating the sharks. So sharks have electro receptors in
Speaker 2: their snouts. These are called the ampulae of lorenzini. They
Speaker 2: are actually very sensitive receptors that can detect tiny electrical
Speaker 2: signals and they can use this to locate prey. These
Speaker 2: are essentially pores in their snout filled with a conductive
Speaker 2: jelly and at the bottom is a cell a electroreceptor
Speaker 2: cell that is sensitive to the flow of electricity, and
Speaker 2: when that stimulates the cell, it releases a signal to
Speaker 2: a nerve which goes to the shark's brain, and the
Speaker 2: shark notices the electrical pulse. And because they have rows
Speaker 2: and rows of these pores of these electric receptors, they
Speaker 2: are also able to tell the direction of the electrical signals.
Speaker 2: So that's how they use it to locate locate electrical
Speaker 2: signals underwater. And this is useful because muscle movements send
Speaker 2: off electrical little electrical signals, because your muscle movement is
Speaker 2: actually powered by electricity in a way, and so this
Speaker 2: is the way that the shark can locate prey in
Speaker 2: the water. So, because these are so sensitive, if they
Speaker 2: are over stimulated, like by rubbing the shark's snout, this
Speaker 2: will actually trigger a state of tonic immobility. So you
Speaker 2: might have heard before that like bonking a shark on
Speaker 2: the snout immobilizes them. That's somewhat true. I wouldn't like
Speaker 2: put yourself in the position where you have to try that,
Speaker 2: but yeah, like rubbing, rubbing the shark snowls getting a
Speaker 2: lot of sort of agitation on the shark's nose cana
Speaker 2: overwhelm that electro receptive system and then cause them to
Speaker 2: kind of go into a sort of dazed catatonic state.
Speaker 2: In other species of sharks, such as the zebra shark,
Speaker 2: you can actually apply some pressure to the caudal thin,
Speaker 2: that is, the tail thin by firmly grasping it, which
Speaker 2: has been observed to also induce tonic immobility. So why
Speaker 2: do sharks have this secret power down mode when it
Speaker 2: doesn't seem to benefit in fact, seems to be somewhat
Speaker 2: of a liability. Well, there are three basic theories which
Speaker 2: are not mutually exclusive. The first theory is that it
Speaker 2: is a defensive technique to play dead if a predator
Speaker 2: corners them. Obviously, it's not so useful for the great
Speaker 2: white when orcas are smart enough to exploit it. But
Speaker 2: it's potentially of vestigial response that benefited earlier evolutiontionary iterations
Speaker 2: of sharks. So not necessarily the great white that doesn't
Speaker 2: really need to fear predation too much, unless unless it
Speaker 2: is ironically stunned. But you know, the great white shark
Speaker 2: may have retained this trait. Maybe other species of sharks
Speaker 2: that preceded the great white shark. This was useful for
Speaker 2: And remember, with evolution, outdated or bad adaptations don't automatically
Speaker 2: go away unless the selective pressure is strong enough or
Speaker 2: more positive mutation arises. So we can have a lot
Speaker 2: of evolutionary adaptations that used to be good for us,
Speaker 2: used to be helpful, but are no longer so helpful.
Speaker 2: One of the theories of like that jerk that you
Speaker 2: do as you're falling asleep is that it's sort of
Speaker 2: this old trait that we had when we were tree
Speaker 2: dwelling and kind of having like this sense of falling
Speaker 2: or alertness when we're trying to fall asleep would actually
Speaker 2: be beneficial. Now it's not so beneficial, but it's not
Speaker 2: because it's not necessarily impacting our survival all that much.
Speaker 2: In terms of yes, it might be hurting some of
Speaker 2: our sleep quality, then the trade is not going away.
Speaker 2: Now you might ask, well, for these sharks, the orcas
Speaker 2: are killing the sharks, that seems like it's impacting their survival,
Speaker 2: And yeah, you are correct. It's just like you need
Speaker 2: enough sharks to be killed in this way that it
Speaker 2: would be making quite a marked difference in terms of
Speaker 2: their survival, and you would also simultaneously need a mutation
Speaker 2: in sharks that allowed them to not have this catatonic response,
Speaker 2: so either way. So the second theory as to why
Speaker 2: sharks have this tonic immobility response is that it's a
Speaker 2: part of courtship behavior, so the female will relax during mating.
Speaker 2: So when sharks mate, that's one of the rare times
Speaker 2: that the shark might be somewhat upside down. So this
Speaker 2: is supported by some evidence that female sharks are more
Speaker 2: affected by tonic immobility. So the ability for the female
Speaker 2: shark to, like when she's upside down, to kind of
Speaker 2: like not thrash around and stuff might make matings more successful.
Speaker 2: The third theory is that it is to protect the
Speaker 2: shark from overwhelming sensory input, basically calming them down if
Speaker 2: their senses are overloaded. This theory basically comes from the
Speaker 2: fact that sharks, when they're overstimulated, like I was talking
Speaker 2: about earlier with their electro receptors, will go into tonic immobility.
Speaker 2: I kind of, I mean, you know, personally, I find
Speaker 2: this the least compelling theory because I'm not sure how
Speaker 2: being sort of soothed is necessarily advantageous. Usually there's some
Speaker 2: like reason, uh for for that tonic immobility that would
Speaker 2: improve your survival chances, not not just like oh, like
Speaker 2: they're overwhelmed and then this is a way to like
Speaker 2: protect them from overwhelming sensory input. I'm not I'm not
Speaker 2: totally convinced about that, but you know, maybe I'm not
Speaker 2: fully understanding it, so it could be true. Yeah, so
Speaker 2: that those are the main theories behind why sharks will
Speaker 2: undergo tonic immobility when they are flipped over. And yeah,
Speaker 2: I mean it's it's a really interesting behavior. I feel
Speaker 2: like it kind of humanizes sharks a little bit. It's
Speaker 2: like they are also vulnerable. They are little little sea
Speaker 2: puppies that bite you real hard if you if you
Speaker 2: play with the wrong species. Anyways, we're gonna take a
Speaker 2: quick break, and when we get back, we are going
Speaker 2: to answer another listener question. Next listener question, Hi, Katie,
Speaker 2: I've heard that because our primate cousins such as chimpanzees, bonobos, etc.
Speaker 2: Are primarily quadrupedal, they can recognize each other by just
Speaker 2: looking at their butts. Do you think that's just like
Speaker 2: how human brains are prime to identify faces, and we
Speaker 2: see faces in clouds trees and other patterns I eat
Speaker 2: pair idolia. Perhaps chimpanzees look up at the clouds and
Speaker 2: see imaginary butts up there, or look at some patterns
Speaker 2: and tree bark and think, hey, that looks like a
Speaker 2: rear end. The world is full of butts. So this
Speaker 2: is from Luke. I love this question. So the question
Speaker 2: is whether pair idolia for butt centric primates might cause
Speaker 2: them to see butts in the clouds. And to answer this,
Speaker 2: we have to look into whether the way that primates
Speaker 2: see butts is the same way that that humans see
Speaker 2: and recognize faces. So it is true that chimpanzees are
Speaker 2: primed to recognize them friends butts. I want to talk
Speaker 2: about a study that explored this because it's really interesting
Speaker 2: and also super funny. It's called getting to the Bottom
Speaker 2: of Face Processing. I gotta love upon in the title
Speaker 2: of a study. So not only does the study demonstrate
Speaker 2: that chimpanzees are primed to recognized individual chimpanzee butts, but
Speaker 2: they also make the case that the ways in which
Speaker 2: chimpanzees sea butts is the same way that human beings
Speaker 2: see faces. And they even speculate that human faces may
Speaker 2: have evolved to look more like primate butts. Before you
Speaker 2: feel insulted, let me go over the whole study. So
Speaker 2: researchers used photos of human faces, chimpanzee faces, human butts,
Speaker 2: chimpanzee butts, human hands and feet, and chimpans and feet,
Speaker 2: and they tested the recognition of these photos in humans
Speaker 2: by asking them to match same photos, so like, the
Speaker 2: same face, the same feet, the same butt, et cetera.
Speaker 2: And then they did the same thing with chimp participants
Speaker 2: who were you know, they were raised in a lab
Speaker 2: facility in Kyoto where they have sort of a chimp population,
Speaker 2: a captive chimp population, who are used in behavioral studies.
Speaker 2: So there's something called the face inversion effect, where it's
Speaker 2: much harder and it takes longer for people to recognize
Speaker 2: faces that are upside down. This is due to the
Speaker 2: mismatch between an upside down face and the schema, the
Speaker 2: template of the face that we have in our brains,
Speaker 2: which is right side up. So we're actually born with
Speaker 2: this schema, this template of sort of the normal proportions
Speaker 2: of a human face as we're when we're born, and
Speaker 2: as we age, it develops in complexity. So humans are
Speaker 2: particularly adept at recognizing faces and because of our sensitivity
Speaker 2: to the facial pattern, we are sometimes getting false positives,
Speaker 2: so we'll see faces in random patterns such as clouds
Speaker 2: or dirt or tree bark. In some cases the opposite
Speaker 2: is actually true. So there are some people who have
Speaker 2: a very difficult time recognizing faces. It's called prosopagnosia, also
Speaker 2: known as face blindness, and it can be very challenging
Speaker 2: for people with face blindness to tell people apart and
Speaker 2: actually for them like when there are these Sometimes there
Speaker 2: are paintings and stuff where they hide human faces in
Speaker 2: like a natural scene or pattern or like an a
Speaker 2: rock face, and people with prosapognosia have a much harder
Speaker 2: time seeing hidden faces that are intentionally put in paintings.
Speaker 2: So onto chimpanzees. Chimpanzee butts might look unattractive to us,
Speaker 2: but to chimps they are beautiful and they can be
Speaker 2: signs of reproductive readiness. There are sexual swellings and coloration
Speaker 2: that indicate a female is fertile and receptive and being
Speaker 2: able to recognize the individuals but is really important because
Speaker 2: this can help them with sort of social situations in matings,
Speaker 2: so they don't have any kind of inbreeding and other
Speaker 2: just social applications of knowing who this individual is. So
Speaker 2: in this study, the researchers predictably found a significant inversion
Speaker 2: effect for human participants trying to match upside down faces,
Speaker 2: just as what is expected. But they also found this
Speaker 2: inversion effect for chimpanzees but with butts. So this means
Speaker 2: that the chimpanzees likely have a developed specific butt template
Speaker 2: that they have in recognizing other chimp butts, far more
Speaker 2: than they have in terms of recognizing faces, hands or feet,
Speaker 2: just as humans have a very specific template for faces.
Speaker 2: But we did really poorly on this test trying to
Speaker 2: recognize butts, hands or feet. So the I thought this
Speaker 2: was a really inventive study, a really really creative, interesting study.
Speaker 2: The downside, which the author's acknowledge, is that there is
Speaker 2: a pretty small sample size of chimpanzee participants. There were
Speaker 2: only five who were trained to partake in the study, which,
Speaker 2: you know, it's just the limitations of you don't have
Speaker 2: access to a huge pool of chimpanzees who can participate
Speaker 2: in this study. They're also captive chimpanzee, so their behavior
Speaker 2: might be different from wild chimpanzees. Again, that's a really
Speaker 2: hard to avoid limitation with studies on chimpanzee behavior. Still,
Speaker 2: I think it's a really interesting study, and I think
Speaker 2: it's really likely that chimpanzees have a mental butt template
Speaker 2: that is similar to our mental face templates that allow
Speaker 2: us to recognize faces. The study authors also speculate that
Speaker 2: as humans developed more upright postures, we switched from being
Speaker 2: interested in butts to being interested in faces. I mean,
Speaker 2: obviously a lot of people still like butts. I'm not
Speaker 2: saying that people don't like butts, but faces became the
Speaker 2: primary target for recognition for sexual attractiveness, being able to
Speaker 2: determine someone was like, sexually mature, et cetera. They also
Speaker 2: speculate that faces may have evolved to fit the butt
Speaker 2: schema in terms of sexually attractive things, being similar to
Speaker 2: the same kinds of cues and butts that were sexually attractive.
Speaker 2: Like I'm not joking plump, red cheeks, red lips, and
Speaker 2: symmetry all being attractive in both chimpanzee butts and human faces. So,
Speaker 2: I mean, to be clear, this is just these study
Speaker 2: authors speculating they don't really have evidence to show that
Speaker 2: human faces evolved to look like primate butts, But you
Speaker 2: know if you want to compliment someone by saying they
Speaker 2: look like a chimpanzee, but I'm not going to stop you.
Speaker 2: So in answer to the question, I would guess that, yes,
Speaker 2: I think chimpanzees probably do see butts in clouds, in
Speaker 2: tree bark, I think they have paridolia. But for chimpanzee butts,
Speaker 2: I think it makes a lot of sense that if
Speaker 2: they are so primed for the pattern recognition of other
Speaker 2: chimpanzee but that they would see it in random patterns
Speaker 2: as well. They probably dream of butts. So you know,
Speaker 2: I think that that. I mean, obviously we cannot get
Speaker 2: inside the brain of a chimpanzee. No for sure that
Speaker 2: they see butts in these patterns, but I would guess
Speaker 2: that they do. So we're gonna take another quick break,
Speaker 2: and when we get back, we're gonna answer another listener question.
Speaker 2: Next listener question, Hi, Katie, this terrifying wasp landed in
Speaker 2: my pool today. I live in Utah. Do you know
Speaker 2: what kind of wasp that is and why it needs
Speaker 2: a three inch long stinger? My kids won't go outside anymore.
Speaker 2: By the way, Love the podcast, been listening faithfully since
Speaker 2: you began. Thanks Tim f Hi Tim, So, good news,
Speaker 2: your kids can play outside without worry, at least when
Speaker 2: it comes to this mystery bug. So let's talk about
Speaker 2: this mystery bug. So Tim sent me a photo of
Speaker 2: what looks like a wasp with a frighteningly long stinger,
Speaker 2: like longer than a flu shot needle. Also very thin,
Speaker 2: So overall, this is an extremely menacing looking wasp. It's
Speaker 2: you know, fairly big too. It's not not a little
Speaker 2: tiny thing it is it looks like if it stung
Speaker 2: you, you would be having a real bad time. But here's
Speaker 2: the good news. This is not really a stinger in
Speaker 2: the same sense as we're used to on like honey
Speaker 2: bees or wasps that can sting you. This is actually
Speaker 2: an ovipositor. So an ovipositor is a long tube that
Speaker 2: is used to deposit eggs. So this is indeed a wasp.
Speaker 2: The bug that Tim sent me photos of, it's a
Speaker 2: species of ignumind wasps. They are actually parasitoids, meaning they
Speaker 2: lay their eggs in or on a host organisms and
Speaker 2: the eggs and larvae benefit from the host while also
Speaker 2: harming and eventually killing the host. So, based on the
Speaker 2: photos Tim sentmi and the fact he lives in Utah,
Speaker 2: leads me to believe that this is the giant ignumind
Speaker 2: wasp also known as Megarisa macarus. It sounds menacing, but
Speaker 2: you actually have nothing to fear unless you happen to
Speaker 2: be a pigeon trimix horntail. So a pigeon trimix horntail
Speaker 2: is not a bird at all, but actually another insect.
Speaker 2: So horntails are in the order Hymenoptera, so they are
Speaker 2: related to bees, wasps, and ants. They look a bit
Speaker 2: like a wasp, but without the hourglass figure. Uh. They
Speaker 2: use what is basically a drilling tool on their posterior
Speaker 2: end to bore into soft, decaying bark on unhealthy or
Speaker 2: dead trees. This drilling tail is fascinating in that it
Speaker 2: has microscopic interlocking valves with teeth that help drill into
Speaker 2: the tree bark by basically stepping forward and catching on
Speaker 2: the wood as it goes in. So it also uses
Speaker 2: a separate tube, the ovipositor, to lay eggs in the wood.
Speaker 2: So here's where the giant ignumenoid wasp comes in. She
Speaker 2: detects the larvae of the horntail living in the wood,
Speaker 2: then she lifts her posterior, and her ovipositor is actually
Speaker 2: too long to start drilling in the wood. If you've
Speaker 2: ever sort of tried to use a tool from a
Speaker 2: weird angle, you'll know what I mean. Uh So, she
Speaker 2: has to coil up the ovipositor like measuring tape in
Speaker 2: a special expandable sack on her posterior. So then when
Speaker 2: she's coiled this up, she shoves it into the bark
Speaker 2: and starts boring into the wood, and the ovipositor win
Speaker 2: unwinds as she bores. It's kind of like a drain snake.
Speaker 2: At this point, you can probably tell I do a
Speaker 2: lot of home maintenance. So not only does her ovipositor
Speaker 2: lay eggs, it does also inject venom, so luckily not
Speaker 2: into humans, but into the larva of the horntail. This
Speaker 2: doesn't kill the larva. Even worse, it paralyzes it, so
Speaker 2: the wasp can lay her egg on the now frozen larva,
Speaker 2: and when her egg hatches, her larva feeds on the
Speaker 2: immobilized horntail larva with no resistance. Since the larva of
Speaker 2: the horntail is still alive, it stays fresher for longer
Speaker 2: as the wasp's offspring slowly eats it, it will eventually
Speaker 2: kill it once it has eaten enough of it. So
Speaker 2: if you're a horntail, giant, igneumenoid wasps are indeed terrifying
Speaker 2: and that long ovipositor is a sign of death. But
Speaker 2: to humans they are completely harmless and they do not
Speaker 2: use their stingers on people. So unless you've been cosplaying
Speaker 2: as a dead tree for too long and a horntail
Speaker 2: has laid its eggs in you, then maybe yes you
Speaker 2: should be worried, but otherwise normally know they present no
Speaker 2: harm to humans. Interestingly, the stingers that we know from
Speaker 2: bees and wasps who can't sting us are actually evolved
Speaker 2: forms of the ovipositor. So the ovipositor apparatus evolved into
Speaker 2: the stingers that we know and love maybe don't love
Speaker 2: that are on bees, wasps hornets that can sting us.
Speaker 2: So the venom will actually instead of depositing eggs in
Speaker 2: this instance, when it be or a wasp or hornet
Speaker 2: stings you, it will deposit venom. And so it's an
Speaker 2: interesting thing to see this ovipositor in these ignominoid wasps
Speaker 2: because it is kind of like you have have like
Speaker 2: a stinger action going on because it does paralyze the
Speaker 2: larva host with venom, but it also is working as
Speaker 2: an overpositor to lay its eggs onto the host. So
Speaker 2: very interesting stuff. Thank you so much for sending me
Speaker 2: this picture, and thank you guys so much for your questions.
Speaker 2: If you out there have a question a bug you're
Speaker 2: terrified of that you found in your backyard, I want
Speaker 2: to say hi, send pictures of your pets. You can
Speaker 2: write to me at Creature Featurepod at gmail dot com.
Speaker 2: I'll be answering the mystery animal sound game question next week,
Speaker 2: so stay tuned for that if you are interested in
Speaker 2: finding out what that mystery animal sound was from last
Speaker 2: week's episode. And also thanks for bearing with me. If
Speaker 2: you notice my voice is a little huskier, a little
Speaker 2: a little more gravelly, I'm getting over just like a
Speaker 2: little cough, a little sore throat, so my voice should
Speaker 2: go back to normal unless it's permanently now really husky
Speaker 2: and gravelly. Who knows. Anyways, Thanks guys so much for listening,
Speaker 2: and thank you to the Space Cossics for their super
Speaker 2: awesome song XO. Lumina. Creature features a production of iHeartRadio.
Speaker 2: For more podcasts like the one you just heard, visit
Speaker 2: iHeartRadio app, Apple Podcasts, or Hey guess what wherever you
Speaker 2: listened to your favorite shows. I'm not your mother. See
Speaker 2: you next Wednesday.