Intro

David: [00:00:00] Welcome to episode 13 of STEMology

[00:00:02]Sophie: [00:00:02] A podcast, sharing some of the interesting fun, and sometimes just patently bizarre news in science, technology, engineering, or maths,

[00:00:10] David: [00:00:10] your hosts are Dr. Sophie Calabretto and Dr. David Farmer.

[00:00:13]Sophie: [00:00:13] Today. We’ll be talking about Wallaby protection, a blind first

[00:00:18]David: [00:00:18] Meatloaves Rock teeth and gray wolves.

Wallaby Protection

[00:00:21] Sophie: So today we’re talking about conservation  and specifically we’re talking about conserving an adorable marsupial and what I can only presume as the arch nemesis of the hammerhead shark, the nail tail Wallaby.

[00:00:41] Sophie: [00:00:41] Did you look up the nail tail, David  it’s called the nail tail because they have a horny spur at the end of their tail, but it is unknown whether the nail tail spur a function

[00:00:51] David: [00:00:51] So, okay. Yeah. So they’re not the functionally nailed tailed wallabies, though. They’re just the nail tail wallabies.

[00:00:56]Sophie: [00:00:56] No, but they do have a white bridal line that runs from the back of their neck, around their shoulders. So they are bridled,  and they are nailed tailed, But we don’t know why.

[00:01:05] David: [00:01:05] But  they’re flippantly or frivolously nail tailed, as opposed to functionally nail tailed.

[00:01:09] Sophie: [00:01:09] Yes.  And they’re getting eaten by feral cats, like a lot of our native animals in Australia.  They get absolutely decimated by introduced predators, but what they found is not all of them get eaten by cats. It’s only the little ones.

[00:01:23]David: [00:01:23] only adorable animals

[00:01:25] Sophie: [00:01:25] Yeah, the bigger ones. Obviously they can still survive. So if they’re less than three kilos, apparently 50% of the population of bridled nail tail wallabies gets eaten, whereas for adults, between three and eight kilos, only 20% of the population gets eaten by ferral cats.

[00:01:42] So they’ve gone. Okay. We need to intervene, but obviously we only need to intervene when they’re little. And so they, they came up with the idea of this exclosure Dave, I’d never heard of the word exclosure before

[00:01:55]David: [00:01:55] No me neither. It’s a strange word because it’s usually enclosure, which I understand because you closed something in Azure and that’s enclosure.

[00:02:04]Sophie: [00:02:04] Yeah. And I thought then maybe I was like, it’s just an enclosure outside, but no one exclosures specifically an area from which unwanted animals are excluded. Like it’s very specific about animals. And So, this is some work that came out of UNSW and what they did is in terms of this intervention or giving these baby bridled nailed tail wallabies a headstart is  at Avocet nature refuge. Which is in Queensland, it’s south of Emerald in central Queensland. And the idea was to keep them safe from alien predators, but mainly cats.

[00:02:32] So the idea is they could still be snatched by something else. They could get, you know, like an Eagle or python could still come and mess them up. They retain some of that predator awareness, but it looks like the main predator is the feral cat. So it sort of keeps the feral cats out and they had very good results.

[00:02:48] David: [00:02:48] So, yeah, for anyone who was worried that these animals who are adorable, tiny little adorable marsupials could not be eaten at all, that’s not the case. They can still be eaten by things like phytons and Eagles. And that’s important because they need to learn how to not be eaten by those things.

[00:03:01] Sophie: [00:03:01] That’s true. Yeah, exactly. If we take away, their not-being-eaten skills. It doesn’t matter if they get bigger, they’ll still get eaten.

[00:03:07]David: [00:03:07] Yeah. So  this is a quote from the paper, the survival rate of wallabies from a time of entry, to exit from the headstart enclosure, which is what it was called was 89%. So that was up from about 50% survival when they’re tiny to 89% in the exclosure, at which point they can take them out.

[00:03:24] And they’re big enough to not really get eaten by cats. But what I really enjoyed was the detailed, the path things that happened to the wallabies.  That did come to some harm in the exclosure. Survival went up to 89% with one Wallaby euthanized due to injury, which is very sad, four killed by birds of prey, which is very sad.

[00:03:39]Two Wallaby’s found dead from misadventure, presumably they were crushed to death by a Boulder or killed by a poison dart while trying to retrieve a golden idol from an Aztec temple. What happened to these wallabies?

[00:03:52] Sophie: [00:03:52] I don’t know. I mean, you’ve got to assume it’s something like that. And it’s something that you wouldn’t expect a Wallaby to do because otherwise why wouldn’t they specify it in the paper that one fell off a rock, because it was hanging out with some yellow footed rock wallabies?

[00:04:03] turns out not a rock-wallaby, but no, I think that they might be adventurous  and yeah, misadventure.  I dunno. I think maybe they were trying to build some kind of a vehicle is what I think. And, you know, something exploded.

[00:04:15]David: [00:04:15] I hope that that’s true. Yeah. I’m now having ideas  like images of like the surviving rock wallabies, like walking away from explosions and not looking back at them because they’re way too cool. And those are the ones that survived.

[00:04:26] Sophie: [00:04:26] Yeah. exactly. Then they went And killed a python.

[00:04:29] David: [00:04:29] Yeah. So to clarify,  we’re including cats as an alien predator. It’s not like an alien predator.

[00:04:35] Sophie: [00:04:35] No, it’s, it’s mainly cats and, uh, yeah. And so, and feral cats. And so what they did is they, as you said, they had some good results, but then they looked at the sort of future projections of the population of this species. And basically it doesn’t look good for them. So what they did is they predicted the probability of the persistence of this particular population of the bridled nailed tail Wallaby. And they looked at it over a hundred year period and they compared it to this at, okay. So say we don’t have this headstart program or we do have it. And we run it for 5 years or 10 years or 20 years or 50 years. And then we stop what happens to the population of these things after that.

[00:05:12] And it turns out that, um, Extinction would basically result in all of them. It would just take longer. So if this headstart program didn’t exist for this particular population, they would all die out in two years. Or if you ran this headstart program for 50 years, they would all die out in 52 years. So basically it really, the wallabies only chance of survival is linked to this headstart program. From what I can tell.

[00:05:37]David: [00:05:37] And what’s delightful about it as well, is that it’s much cheaper than, uh,  what we’re more familiar with, which is an enclosure. So Y Traditional wildlife park, where you have to kind of make a big predator proof area and keep the wallabies separate from basically everything forever. Here, we just keep them safe from cats for a short time, which is not only easier, it’s cheaper. So instead of costing like a million dollars for a big wildlife park, we’re talking about a hundred thousand dollars to bring them in to this wildlife park until they grow to a certain age and then let them go again, which is good.

[00:06:08] Sophie: [00:06:08] It is good. And, I actually,  used to live in New Zealand and apparently this is like a common thing that they do there. So I remember specifically going to, so I guess they were slightly more, it was like an open sanctuary, and the idea was you could go in there and do things, but they had these very clever fences, but of course, New Zealand is very peninsular-y, so you can just kind of stick a fence across the peninsula. So the one that I went to a few times as near Metricon, or which has a place in the north island, which is lovely for a holiday, and that’s theTawharanui open sanctuary, and New Zealand has this issue where a lot of their native animals are flightless birds.

[00:06:40] So it’s very important to keep, you know, cats out, but then also they have to compete for food with like rats and stoats and possums and stuff. And apparently, so this particular one that I ‘ve been to. It’s um, they only had to build a 2.5 kilometer predator proof fence because it was built on this peninsula.

[00:06:55] And apparently doing this 14 species have returned to breed, or they’ve been re-introduced successfully to this sanctuary area, including all your fun, little birds, like the Kiwi and the Takehei and the Patek and the Kakariki and all these they’re very pretty little birds, but yeah, useless against a cat.

[00:07:11] So this is, as you said, it’s much, much cheaper and it’s really nice idea. And if it means that these cute little wallabies don’t die. Let’s do it. You jerk cats

[00:07:20] David: [00:07:20] Well, they can still die. It’s just that now they’re free to die from misadventure.

[00:07:24] Sophie: [00:07:24] Exactly

A Blind First

[00:07:25] Sophie: okay. So Dave, there’s this interesting story. That’s come out of an international collaboration and, I’m not going to name all of the places, but we’ve got some places in France, some places in the US and what they’ve managed to do is restore sight to a man who was previously blind due to a neurodegenerative eye disease called retinitis pigmentosa, which is basically a progressive and inherited genetic disorder that leads to loss of vision. And I looked it up and apparently the underlying mechanism involves progressive loss of the rod photoreceptor cells, which are the ones that have to do with like night vision and low light.

[00:08:08] And then generally followed by the loss of  photoreceptor cells, which is your color and bright. So all vision. So basically his vision has degenerated to the point that he can tell the difference between light and no light, but he can’t see anything. And they’ve done some really cool optogenetic vision restoration, Dave, and given him sight back in one eye

[00:08:28] David: [00:08:28] Yeah. So basically using a combination of a gene therapy and what I can only describe as space goggles.

[00:08:35] Sophie: [00:08:35] They are space goggles.

[00:08:37] David: [00:08:37] Yeah, these, these researchers have done something, which is, sounds like a big deal. They’ve restored limited sight to a blind person. So basically, as you said, and I don’t want to get too much at division because it’s really complicated and hard to understand, but basically usually the back of your eye is coated in light sensitive proteins so that when the light hits them,  the light signals get translated into neural signals, which are interpreted by your brain and you see. So if those don’t work correctly, then you can’t see.

[00:09:02] So basically what they’ve done is because those cells aren’t working properly because there’s like sense of the proteins aren’t working properly. They’ve used what’s called an adeno associated virus, which is just a kind of virus. And they’ve used it to deliver genetic material into the eye. And specifically here, they delivered it into one eye, one of the patient’s eyes and his worst seeing eye they delivered this virus into. And they were using this virus to deliver genetic material into his eye. And the genetic material that they delivered was the instructions because basically viruses are just little gene delivery systems. And usually what viruses do is they go into your cells and use the machinery of the cell to generate copies of themselves.

[00:09:43] And that’s how viruses replicate. And that’s how they make you sick. But here, these viruses deliver the instructions to make a different light sensative protein to the protein that’s usually present in your eye. And it’s actually the light sensitive protein that’s present in algae. So basically they turned the back of this guy’s eye into a kind of human algae hybrid of sorts

[00:10:04] Sophie: [00:10:04] Like a photosynthesizer?   No. That’s energy. That’s different,Dave

[00:10:07] David: [00:10:07] No, it doesn’t make energy. It just, it just means it basically it’s an, it’s an ion channel. So basically it provides a means to activate the cells when light hits them. It’s just an alternative way of doing it to what the human way usually is.  So now his eyes are sensitive to this one, wavelength of light 595 nanometers, which is what these proteins are activated by, but that’s not enough, that will not be activated by ambient light. So he can’t now see just with the normal light. So that’s where the space goggles come in, right?

[00:10:37]Sophie: [00:10:37] Can I just jump in with the 595 nanometers, Dave? You know, that’s like a banana yellow. I was intrigued as to where that fell in the spectrum. And it turns out that if you wanted to paint your house, this particular color, if you go to, um, Avery paints and get their Primrose yellow, that would be the closest to this particular kind of yellow. But Yeah. Anyway, sorry. Continue Dave space goggles.

[00:10:58]David: [00:10:58] So because, I presume the intensity of light that comes into the eye is not sufficient to activate this protein, this algae protein, they needed another step, which was to give him the space goggles. And basically what the space goggles did was they used something called a neuromorphic camera to map the image that was present in front of him, and then beam that information into his eye, such that it struck the light sensitive proteins and built up an image of what was in front of him. And doing this, he was able to successfully perceive and locate and touch so he could reach out and touch various objects that have been placed on a table in front of him, including fairly randomly a notebook, a staple box and the tumbler.

[00:11:42] Sophie: [00:11:42] Yeah, I got sad. I thought they could have given him some cool things to grab.

[00:11:46] David: [00:11:46] I’m not very sure. So I have mixed feelings about this too, because a tumbler, presumably that’s just a tumbler of the sort that can hold liquid and be drunk from  as opposed to like a somersault or gymnast. But it says objects.

[00:11:57] So irrespective of whether they can be distinguished by the Blind  or not.   It’s wrong to objectify a tumbler

[00:12:03] Sophie: [00:12:03] Tumblers are people too, dave.

[00:12:04] David: [00:12:04] Yes, absolutely. That’s why I have to say. Um, so this is really, really, really cool. And it’s the first time it’s ever been done in a neuro degenerative disease. And  the neuro morphic camera’s really cool. So this is basically a

[00:12:16] Sophie: [00:12:16] Yeah. I’d never heard of this camera. before.

[00:12:20] David: [00:12:20] Yeah. So my understanding of it is it doesn’t take a series of still images and then beam that into the eye. It basically works on a pixel by pixel basis.

[00:12:28]Sophie: [00:12:28] Yeah. So I think, you know, normally like a camera, it gets its light sort of. Like through a shutter, but I mean it’s a digital camera so that it’s made up of pixels and each pixel can basically, it operates independently and asynchronously and it like, it can pick up distinct events.

[00:12:45] And so that’s how you say that they sort of, yeah, they take this image, but they can render it pixel by pixel in lights, in these goggles.

[00:12:52]David: [00:12:52] Yes. And I presume it’s been done that way, because that must be more similar to how the eye works. And, but again, I’m not sure because vision is so bloody complicated and we’d really need someone to come on the show and explain it to us, how it works properly. but yeah, there’s a really interesting combination of really exciting gene therapies and really exciting technology that have sight,the the blind.

[00:13:13] Sophie: [00:13:13] yeah. And then apparently this patient testified to a major improvement in daily visual activities, but only wearing the goggles. And I found this with a really sad bit with when they took him outside to look at things and, um, he was able to identify and count the number of white stripes on the crosswalk outside the lab.

[00:13:29] And it’s like of all things to be, I mean, like it’s an achievement, if you can’t do that before, but I don’t know, like take him to the zoo or the fair or something and get him to see if he can throw a dart at a balloon. I think that would be like a more fun test, maybe slightly more dangerous. But Yeah so I guess it does mean that he would need to wear these space goggles.

[00:13:47]They didn’t have a picture of them front on, but from the side they looked a little bit, you know, how you can get those sunglasses that fit over your glasses. When you’re an old person, that’s what they look to me, which I guess is like, you know, he’s 58. It’s not that old, but it was really getting to the point that he would start wearing those as acceptable eyewear.

[00:14:04] David: [00:14:04] Absolutely 58, absolutely. They’re threshold age for wearing glasses over your glasses. Um, with the white stripes thing, that could have been a good guess as well. Like I think it’s a shame. That’s what they showed him, but like everyone knows there’s two white stripes, this Jack and Meg.

[00:14:18] Sophie: [00:14:18] Exactly.

[00:14:18] David: [00:14:18] He could have just known that in advance.

Meatloves Teeth [00:14:32]

[00:14:32] Sophie: [00:14:32] So Dave, from genes in your eyes to metal in your teeth, I want to talk to you about a giant Pacific chitin, which is a type of big mollusk, also known as the wandering meatloaf.

[00:14:45]David: [00:14:45] so I’m excited because you’re so excited about this story, Sophie.

[00:14:50]Sophie: [00:14:50] it’s just because, okay, so we’re talking about the  pacific chitin also known as a gumboot chitin, also known as the giant Western fiery chitin. It’s Latin name means Stella’s hidden chitin, Stella being the person who found this chitin, it is the world’s largest chitin and it grows up to about 35 centimeters long, but it is nicknamed the wandering meatloaf because it’s giant leathery, sort of red brown, and looks a little bit like meatloaf.  And we know a bit about this chitin, so it’s like all other chitins. I’m just going to say the word chitin as much as I possibly can. It has eight almond plates running in a flexible line down its back.   Can I just call this one meatloaf because. The, uh, wandering meatloaf is too many syllables, so meatloaves are hidden by its leathery, upper skin or girdle.

[00:15:37] And what I learned as well was you can eat this, but it’s quite rubbery and tough. anyway, so these things feed on algae just like, the algae injected into the man’s eyeballs from the previous story. Well, the way that they do this, as they have several dozen rows of teeth on this sort of slender, flexible tongue-like appendage called a radgular, and they kind of scrape this across the rocks to eat their algae.

[00:16:03] And we already knew that their teeth, a covenant thing called magnetite, which is the hardest stiffest known biomineral today. And do you know what I learnt Dave? We have magnetite in our brains.

[00:16:12]David: [00:16:12] oh, I didn’t know that.

[00:16:14]Sophie: [00:16:14] So they’re found in like a lot of bio things the fact that there’s magnetite in these teeth and is not like a weird thing at all.

[00:16:20] So apparently we have magnetite in various parts of our brain, including like a bunch of the lobes in the brain stem, in the cerebellum and the basal ganglia. And I don’t know what any of those things do, but I think you might. and so what they had discovered now, though. So this is some work that’s come out of Northwestern university, at the Argonne national lab and the University of Stuttgart and apparently these hard magnetic teeth also possess a rare mineral previously seen only in  rocks. So it’s this thing that we’ve only seen in rocks and then apparently in this wandering Meatloaf’s teeth, there’s also this rare mineral called Santa Barbararite.

[00:16:58]David: [00:16:58] Yes. So this is an, a morphous ferric, hydroxy, phosphate, mineral hydrate. Eh, it was discovered in Tuscany, Italy in Santa Barbara, funnily enough, which I didn’t realize was an Italian place in addition to an American place, but obviously it is, and that makes a lot of sense.

[00:17:13] But But

[00:17:13] Sophie: [00:17:13] they only found it in 2000.

[00:17:15] David: [00:17:15] Yeah. So it’s very recent and interesting. You can also find it in Victoria,

[00:17:19] Sophie: [00:17:19] Yeah,

[00:17:20] David: [00:17:20] I

[00:17:20] Sophie: [00:17:20] did know that too. Yeah. Maybe after this you could go out and search for some nano-particles of Santa Barbararite. If you’ve got nothing. Oh, no, you’re not allowed to.

[00:17:28] David: [00:17:28] I’m not allowed to do anything. I have to stay inside listeners. It said we’ve just gone into the second week of the two week lock down here in Victoria. So we’re staying inside.

[00:17:35] Sophie: [00:17:35] Dave is very responsible adults. So he’ll stay inside.

[00:17:38]Yeah. So what they did is they analyze the teeth using high energy x-ray spectroscopy. And they discovered that the interface between the teeth and the flesh, which is the thing called the stylist actually contained nanoparticles of this Santa Barbararite, in a softer matrix. And so the cool thing about this is like the Santa Barbararite is very hard, but what they found was the distribution wasn’t even. So the concentration of these nanoparticles was much higher near the surface of the tooth. And then it became sparser where the stylus connected to that softer radgular.

[00:18:12] So the idea is that you sort of had this variation of hardness and stiffness, over at like a very small distance, which is like the size of this tooth, which is apparently just several hundred micrometres, which is a few times the average width of a human hair. So the idea is because they had this varying density, it meant was hard near the top, and then not as hard near the bottom, which meant that it’s sort of more flexible.

[00:18:37] So the idea is you can make this very light strong, flexible material. So then they went a step further and they went, okay, well, what if we got similar nanoparticles and we 3d printed them in this kind of irregular density matrix, can we create strong light materials with varying hardness and stiffness?

[00:18:55] And the answer is yes, Dave.  They used a similar mineral and they put it in two liquids, one containing iron and one containing phosphate.

[00:19:02] And they made themselves like a 3D paste that they used for this 3D printing. And they could print these light materials that were very strong and they had that variation of hardness and stiffness. And they think that the composites might be very useful in robotics.

[00:19:16]David: [00:19:16] Yeah. So this would allow you to marry soft and hard pot parts and robots. So basically you could have a robot that could squirm passed like obstacles because you would have the hard bits. Like I imagine something like hard bits on the outside and squishy bits on the inside, and then you have them married by these nanoparticles and then if it gets stuck somewhere, it can squirm through by compressing it’s compressible bits without having to be super rigid and, you know, kind of robotic,

[00:19:40] Sophie: [00:19:40] Yeah exactly. So  flexible robots for squirming. So, and we got this from, a wandering meatloaf, which I think it’s just the name and just like, if everyone just goes and, Googles wandering meatloaf.   Yeah, it looks like meatloaf, like a Tounge-y meatloaf. I think.

[00:19:53]David: [00:19:53] I mean, yeah, it’s, it’s unsettling. Just the idea of a meatloaf with teeth, the idea of any processed foods, having teeth unsettles me.

[00:20:01]Sophie: [00:20:01] Well, especially when its teeth are made of rocks and magnets , and again, can be eaten, but you know, maybe don’t, if you’ve got other choices, unless you’re into, it says he a rubbery in top. So I assume that it would be a bit like if you overcooked cuttlefish, I feel like that’s the vibe that I’m getting, but I’ve never eaten like a giant mollusk.

[00:20:17] So I don’t know how true that is.

Gray Wolves [00:20:19]

[00:20:19] David: [00:20:29] From toothy mollusk to toothy mammal. We’re talking now about apex predators, their populations, their knock on effects and how well we think about wolves. We think wolves are scary and because human beings thinks wolves are scary. And because they do things like eat our livestock, we’ve kind of systematically hunted them down over the past 200 years, to the point where in the sixties, they were basically right on the brink of extinction. and that’s all due then to things like government bounty programs, hunting pressure, habitat loss, and declines in their prey populations. But in the sixties, we’ve started to sort of realize this is maybe not a great thing that we’re killing these animals

[00:21:09] and

[00:21:09] Sophie: [00:21:09] we should stop killing everything around us.

[00:21:12] David: [00:21:12] Yeah. Yeah, we should stop killing everything around us. And so maybe we should put them back where they came from and you might think that economically that’d be a bad thing cause they start taking livestock. But some researchers in America, specifically at Wesleyan university of Middleton have looked at something very interesting, which is how the presence or absence of wolves in counties in Wisconsin affect the likelihood of you hitting your car with a deer.

[00:21:37] Sophie: [00:21:37] Yeah. So wolves are saving us from deer vehicle collisions, which they refer to as a DVC, which today also stands for Disney vacation club. So when you Google DVC, the first thing that comes up is Disney vacation club, not deer vehicle collisions, but Yeah they found that in a Wisconsin counties where the Wolf populations returned, the number of collisions dropped on average by 24%, which is actually it yields in economic benefit that is  63 times greater than the cost of verified Wolf predation on livestock , as you mentioned. So what they did is they, um, analyzed data on Wolf populations, deer populations, and deer vehicle collisions for 63 counties in Wisconsin from 1988 to 2010.

[00:22:25] Weirdly Dave, there are 72. Counties in Wisconsin. I’m just going to assume that they didn’t have data on nine of them, or they just didn’t like nine of them for some reason. Anyway, so they had this kind of, this two channel kind of hypothesis that they were looking at.

[00:22:39] So to start off with, they were thinking that the larger Wolf populations would just reduce the deer abundance through direct predation. Right. And because there are a fewer deers, they’re less likely to run into your car or your car ‘s less likely to run into them.

[00:22:52] David: [00:22:52] You cannot hit something that has been eaten with your car or , you can, but it will be smaller in mass because it’s been partially eaten and you know, less likely to run onto the road because it’s been eaten

[00:23:02]Sophie: [00:23:02] Exactly like  if it’s been partially eaten on the road, you’re more likely to see it as you approach rather than one just running into the side of your car. And then the second hypothesis was that it’s just the Wolves presence. So apparently wolves use these travel corridors, which are just sort of linear features like roads and pipelines and stuff.

[00:23:19]And it helps them travel efficiently which means that they can kill things better. So the idea is because these wolves are going to be around these roads and linear pipelines, there will be fewer deer, which means, again, fewer collisions because you can’t hit something that isn’t isn’t there really.

[00:23:34] David: [00:23:34] Yeah. So it says very casually wolves use roads and other linear features as travel corridors. But presumably they mean like the sides of roads. Like we’re not talking about roving gangs of bikey wolves, that terrorized  station wagon, bound deer, and run them off the road.

[00:23:49] Like they must be wandering along the sides of roads

[00:23:53] Sophie: [00:23:53] I mean maybe, but then at the same time, I like to think it’s like a motorcycle gang and they’re all wearing leather jackets made out of deer leather because they’ve hunted They’ve eaten them, but they let you know, it’s a Wolf. So, you know, a lot of animals and lot of predators are good at using all of the animal that they catch.

[00:24:07] So they turn their hides into these leather jackets. So if they come off their Wolf motorcycles, they’re not going to, you know, mess up their fur or anything.

[00:24:15] David: [00:24:15] also, they’re an impressive species, but they haven’t really mastered, you know, synthetic textile manufacture as an art form, the way that we have no, thumbs, no thumbs in it.

[00:24:24]so You’ve got wolves basically running down the side of the road, which means that the deer don’t go there or learn not to be around there, which means they’re not near the roads, which means that you don’t hit them with your car, which is great.

[00:24:35] And it turns out that this factor, which they’ve very rightfully dramatically branded the landscape of fear effect.  Landscape of fear effect had much more impact on the likelihood of you hitting a deer with your car than just eating the deer.

[00:24:52]Sophie: [00:24:52] Yeah. And so they said that that means that you wouldn’t get that effect from sort of hunters or something, keeping populations under control in those areas, because it’s really, it’s not The predation that is the thing that is stopping you hitting a deer. It’s the deer, being scared of their landscape of fear caused by the presence of wolves.

[00:25:10]David: [00:25:10] The landscape of fear.

[00:25:12]Sophie: [00:25:12] Yeah. And so that, 63 times more figure that I came up with before. So they said that the average drop of 38 deer vehicle collisions per year in Wolf counties translates to an estimated 10.9 million in savings each year across the state. Whereas previously the state paid around 3 million over the last 35 years to compensate from wolves damages to livestock.

[00:25:36] So that’s that  63 times. But the other interesting thing is that they think there might be more economic benefits that weren’t directly measured in the study, such as reduction to, um, damage in agriculture , by the deers, but also, um, A drop in the Lyme disease frequency as well, because of course,  so Lyme disease you get from ticks that have fed on deer that have the Lyme disease.

[00:25:59] Fun fact I learned is that Lyme disease is caused by Spiral cades which is just a kind of spiral bacteria. This is the genus Borrelia, other kinds of spiral Cates of genus trepanema cause syphilis.

[00:26:11]David: [00:26:11] oh, that’s interesting.

[00:26:12] Sophie: [00:26:12] I’d heard the word spiral cates before, and then I realized it was from Monte Python’s medical love song about STI’s

[00:26:18] David: [00:26:18] it’s better than hearing it from a doctor, I suppose.

[00:26:21] Sophie: [00:26:21] yeah, that’s true. Although, apparently the rate of syphilis in Australia has risen as a result of dating apps, but anyway, I also learned about the way that wolves predate Dave, cause I was quite interested, but it turns out often when they take down large prey, what they sort of do as they injure them.

[00:26:37] So they bleed out and then the wolves just like lie around and hang out while these poor things are bleeding out and then they become really weak due to blood loss. And then it means that the Wolf can eat them, lessening the risk of injury to them. And then I was interested in the bite force dave, so the bite force of  a Wolf is 28 kilograms per centimeter squared, which is approximately 0.00275 gigapascals, which is three orders of magnitude smaller than what a tardigrade can withstand.

[00:27:05] David: [00:27:05] Oh, there you go.

[00:27:06] Sophie: [00:27:06] Every time I hear  force or pressure or anything. I just think of like, compared to a tardigrade, is that good? Or is that bad? So it’s an interesting, um, analysis done in this paper, Dave, and I thought I would try and learn some stats this week and it turns out that it is way above me and it’s too hard.

[00:27:22] David: [00:27:22] It was actually an economic analysis. This was worked on by economists, not by zoologists or  something similar.  It was an economic analysis. So I found it very difficult

[00:27:32] Sophie: [00:27:32] Yeah..  I was like, okay, can I understand how they’ve done that modeling when they looked at the Wolf presence versus Wolf abundance, and you know, how those things impact each other. And what they use was something called a triple differences model, which is also a difference in difference in differences model.

[00:27:47] So normally there’s a thing called a double difference model, which is a difference in differences, which estimates the effect of a specific intervention or treatment by comparing the change in outcome over time between a population in sort of like a treatment group and then sort of like a, control group population.

[00:28:02] So both of these populations would change and one of them would change as a result of this treatment. And then you look at like that difference in the differences,

[00:28:10]David: [00:28:10] it’s like what they call an interaction, right?

[00:28:12] Sophie: [00:28:12] Yeah.

[00:28:12]And so this is a difference in difference in differences. So the difference in difference estimate was  it measured changes in vehicle collision of any type.

[00:28:22] So one’s in involving deer or no deer before versus after the Wolf arrival. So that’s the first difference. In a Wolf versus non Wolf counties. That’s the second difference, but then the triple difference coefficient. So this third difference assesses how the number of deer vehicle collisions changes relative to non deer vehicle collisions before versus after Wolf arrival in Wolf versus non Wolf county.

[00:28:49]I got to that point and I went, you know what? Dave stats is too hard for me. Um, but isn’t that great that we can reintroduce wolves to where they were meant to be anyway. And it stops us from getting in head-on collision with deers. So, I’m glad someone else did that stats. It was terrifying.

[00:29:03] And, um, I think it’s a good outcome.

[00:29:06] It’s terrifying but not as terrifying as the landscape of fear, which is how we introduce wolves to drive down the number of deer, which is good for your car. And it’s good for the public purse, but probably quite stressful if you’re a deer.

Outro

[00:29:19]  David: [00:29:23] And thank you for listening to another fun episode of STEMology. Be sure to check out all the links to these great stories on our show notes.

[00:29:29] Go visit www.stemology.com.au.

[00:29:33]Sophie: [00:29:33] If you have any news that you think is STEM ology worthy, drop us an email stemology@ramaley.media. We would love to give you a mention, if you give us some good ideas,

[00:29:42]David: [00:29:42] Your hosts have been Dr. Sophie calabretto and Dr. David Farmer.

[00:29:46]Sophie: [00:29:46] This is a podcast from Ramaley Media.

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[00:29:52] We look forward to sharing the latest in all things, science, technology, engineering, and maths with you next week, and be sure to bring your friends.