Hello, folks, it’s Kevin Matteson. Again, thanks so much for joining us for our third podcast about extinction and its consequences for the issues in our diversity class. You know the drill at this point, we have three different instructors discussing the papers that were assigned for this discussion. And the goal here is to just reach you all, wherever you are in a different format than the standard written word in the workshops. So this is a complement to what you’re doing in the chorus section. So one of the cool things I think that’s really neat about this is that we have multiple sections of issues about diversity, as as most of you know, with over 200 students currently in the class and about 10 instructors. So this podcast is a way that we can actually be connecting with the entire group, even though in your The actual sections you’re you’re in, you’re just interacting with those students in that instructor. So we are reaching all all the instructors. For issues about diversity, we have shaft cot and kt file and we’ll be joining next for discussion for and then Genie Miller, Martin and Ramana. Kalyan will be joining for our final discussion of the fifth discussion in the course. So, again, drop a note, if you are enjoying this or have comments or on the content or clarifications or anything you want to say, we actually are going to start reading these comments at the end of the podcast for each episode. If you’re okay with that, so feel free to email me at Matteskc@Miamioh.edu or you can give me a call and you can leave a voicemail on my office line and If you’re okay with it, we will go ahead and add that to the podcast for the future. So again, if you just have a thought that was spurred on or how you’re listening to this, where you’re listening to this, we would love to hear your, your ideas. We know you’re all busy, but the feedback is fun, and it helps us sort of build community here. So you can give me a call at 513-529-0837 and leave a message or email me your thoughts and comments. All right, I think that’s it for now. Enjoy the discussion. All right, welcome. This is Kevin Matteson in our second or actually no third, already podcast on discussion, three, four issues about diversity. We’re talking about extinctions and its consequences. And this time we have Romana Callan. here who’s one of our visiting assistant professors. You can say hi
And we also have Kendra Cipollini, who is an adjunct professor and actually lives here in yellow springs, Ohio, where I live as well.
All right. Cool. So, three of us are talking via Skype here and going to have a conversation about the three articles, required readings for this particular discussion. But I thought we’d start off by sharing a little bit about a species that has gone extinct in sort of recent, relatively recent human history.
So Rama, do you wanna start start off with yours?
Yeah, so I’m Rama Callen and I teach a couple sections of issues about diversity this semester. And I I definitely thought about animals first and then I settled on American chestnut would be something I really want my life to have. They’re not technically extinct, they’re functionally extinct. So you will find seedlings out in the forest, but they don’t grow to maturity because of the chestnut plate. So I think it’s really hard for us to imagine what these forests were like the, you know, there were 4 billion American chestnut from Southern Maine all the way to Mississippi and they were the dominant tree species they were, it could be 100 feet tall and 10 feet in diameter. And just seeing those mature forests. I would have loved to have been around during those times. And then you know, when I go for a hike in the woods, I find a three foot diameter white pine and get really excited and these trees are just so massive, and then they produce so much food for for wildlife and humans and consistent food crops every year. So it’s corns and beech nuts have kind of taken over that ecological role, but they they don’t produce consistent food. So I think the wildlife is probably a lot more abundant and different as well, just because you had this constant massive crop of nuts every year. So yeah, I would have liked to have seen mature old groups. American chestnut dominated for us.
Cool. Well, cool. Not cool. For
Modi, for the much of this discussion, actually, but Kendra, I feel like you as a botanist might know something about American chestnut or where to find it. Have you ever seen any mature trees in your life that you know of?
I have seen some flowering trees. So the interesting thing about chestnut is you find them in the future. For those, that rootstock is there so they died back from chestnut blight, but you still have the roots there so they will sprout back. And then the chestnut blight will kill them once they usually get to a certain diameter. And they don’t get past that. But sometimes some get through and you’ll see some flower. I don’t think that I’ve ever seen any fruit in the field certainly. But we have seen some chestnut. My husband is a biologist to looks for chestnut all the time. And his brother who’s also a biologist actually does some work trying to breed in jeans from Chinese chestnut into American chestnut that have resistance to chestnut blight. So for a long time, there was a stand of chestnut in Wisconsin, I believe, that did not have chest enough light, and that’s because it was a plantation that was planted. And the disease did not spread there, that plantations been wiped out. But it was kind of an interesting anomaly so people could still see chestnuts. Not quite in its natural habitat. But the other interesting thing about chestnuts too is that they were a huge food source for a bunch of different animals. There were specialist mops and specialist things that fed on them. And so you know, they’re huge food base for the whole ecosystem, and yet they’re gone now. So it’s kind of mind boggling.
That actually, yeah, it gets into the Cascades in the extinction chains that are discussed in some of these articles. But Kendra, what was what was your species?
So the species that I landed on, was the passenger pigeon, partly because it’s an interesting story, but it also has some local connections. Very last passenger pigeon died in the Cincinnati Zoo. Here, just about an hour from where we live and there’s a little monument to her. Her name was Martha. She was lonely looking for a mate and they couldn’t find nail bait to mate with her. And she, you know, died alone in 1914 wishing for more eggs. But it’s an interesting story because the passenger pigeon was such a bird that was in huge abundance. They estimate you know, 6 billion birds a lot of birds. And the interesting thing about them was that they were nomadic. They were fruit feeders. And they’re also really good fliers. Interestingly, they could fly up to 60 miles an hour, so they were swift fliers, fruit feeders that went nomadically around from where trees were fruiting. Or, you know, plants were fruiting. They kind of swoop in, eat all the fruit hanging out. And then move on to the next place. So you know, there’d be days and days where, you know, a long time, months years where you wouldn’t see the passenger pigeon. And then all of a sudden, just one day would come. And some of the early accounts of this species. were, you know, when these flocks come, they’re like 15 miles long and three miles wide, and they black in the sky, and they were in such abundance, and they’d land and roost at night. And people would go and just like swing bats and swing them out of the trees and eat them and over harvest them. They were so abundant. And, you know, it was one of these ones that people thought would never go extinct. And in the 1800s, sometime, maybe, I don’t know, maybe about 1820. I don’t remember the exact date. But some people noticed, hey, maybe the passenger pigeons can’t really take all this hunting. Maybe the Ohio legislature should do something about it, provide some protection, and the lawmakers came back. They’re like, no, there’s so many Have them we could never make them go extinct. And so, you know, they kind of had some thought about protecting them never did anything. And now they’re gone. And so it’s kind of amazing to again, just like the chestnut, this huge, dramatic species that was super abundant all of a sudden, just, you know, went extinct.
Yeah, that’s I was actually thinking about passenger pigeons recently, and because I was talking with my son about extinct species on the way to school, and I had heard that they estimate they made up like 25% of the abundance of all birds in North America at one point. So and I think I used to wonder how, how it could be possible that humans could hunt something out like that. And the analogy that helped me understand that was thinking about bison And how numerically abundant they were in North America until, you know, these trains moving out west with people that would just shoot from the chain the trains to partially to clear
the lines to some degree
but also to perhaps, you know, erode the sort of social cultural capital of Native Americans and for whatever reasons, but um, you know, if those bison could be brought down to whatever it was, I think less than 100 individuals left at one point I guess yeah. The passenger pigeons as well and especially when these these species are not adapted to humans as predators or humans as predators with guns in that case.
Seems we can be very damaging.
Yeah, and it comes down to to biology to have the organisms as well. So when you know there’s various vulnerabilities, one vulnerability of the passenger pigeon is that it was very social. And we’re in these huge flocks. So they were very easily targeted. And and they were naive to predators as well. But just such large amounts, you could easily sort of get them all in one place.
Yeah, makes me think of monarchs to like the, you know, monarchs are in the top 10, one of the top 10 most abundant butterfly species in much in North America, which is surprising to people because they’re used to hearing about how, you know, monarchs are threatened. But they are threatened because they have these overwintering sites where they congregate, that are, you know, facing a lot of habitat destruction in certain areas. So that tendency, even if you’re numerically abundant to all go to one place, and make you very vulnerable to those things can can still keep you in In you know a threatened state
Cool, well my
cool not cool I should say again.
Cool. My the species I was thinking also thinking about was the Thylacine, or the Tasmanian wolf or sometimes called the Tasmanian Tiger, which was a
that lived in Australia and Tasmania, and was wiped out sometime in the 20th century, I think around the 1930s. They think the last individual died. And it’s kind of an interesting example of synergies of things affecting it. It may have been some disease due to introduced dogs. It may have also been over hunting and persecution by people who consider it a threat to their their livestock. And that might have been also over the course of thousands of years, not just over the last few hundred years that they were declining due to that. So a few things going on with it. But I just think it would have been so amazing to see as a marsupial predator of that size. I don’t think there’s any other examples that I can think of that fill that unique niche evolutionarily. So
have Have you seen the YouTube videos of it?
I know I’m wanting to check that out. Is it like old footage or is it like yeah,
it’s footage from the early 1900s. And it is in a zoo. No and, and the one cool thing about the Thylacine is that it had some kind of unusual anatomy, and then it could open his mouth, super wide. So there’s some videos showing it open its mouth and it looks like something from a sci fi movie. So it’s pretty fascinating. You’re like, what, what the what? So it would have been really cool to actually, you know, see that and, or see more video of it. It’s just like some little pieces, but go on to YouTube and search Thylacine. And there’s some video old video black and white from, you know, before it went extinct.
Cool. Yeah, I’ll have to check that out for sure. And I asked if it was recent, because I know there’s still people that claim they’ve seen it and every now and then videos, grainy videos and such pop up on YouTube, but
that’s the chapter terrified.
Okay, well, um, so this is kind of all it has already brought us to some of the themes in these papers. So, but I think we could start off by talking About the DOD at all article on habitat fragmentation, which I know Rama, you were going to kind of take the lead on helping us walking us through it and maybe any questions and things and Kendra and I can jump in as we go through, but what did you What did you think of this article?
Yeah, so, um, I do quickly want to review, kind of the difference between habitat loss, habitat fragmentation and habitat degradation. I think most of our students are pretty familiar with those concepts. But sometimes when we talk about habitat loss, we’re kind of lumping fragmentation in there and not thinking about so habitat loss, which is like in a forest ecosystem where you lose a third of the global forests. That’s obviously going to reduce the overall area for biodiversity. But then the remaining habitat is fragmented. So
you have these, these three
main drivers within fragmentation which are loss of smaller areas. So a lot of the remaining forests are less than like 10, Hector’s, and then isolation where species are, have a difficult time moving between these patches, and then the impacts of edge because we know edges are very different ecosystems where
there’s different species there. There’s different
amounts of light, different temperature and moisture levels. So, I thought that was useful just to start with that. And then the third being habitat degradation. So, even when we have these remaining habitats, they have different disturbance regimes. They’re impacted by invasive species. She’s a loss of top predators and changes to the community composition. So you might think of like the southeast us is very forested, but it’s a lot of loblolly pine that’s managed for forestry and very low diversity. So I thought it was useful to start out with Did you guys want to jump in on that?
Yeah, I think there’s there is a figure in one of the yard. I don’t think it’s this article, actually. I think it’s, um,
it’s my honor. Oh, yeah.
Yeah, it’s a Roger Brooks. Yeah. Which has like,
all right, Brooke.
Yeah, it has that nice. Like, it’s like a circle and it’s like, oh, the green circle or something. It’s like this is contiguous habitat. And then it has a cut in half and it’s like, this is habitat loss like it’s been dropped down. 50% but it’s but the remaining 50% is all together. And then it shows a final figure, which is like, where it’s been reduced 50%. But it’s like totally fragmented little pieces like a jigsaw puzzle that’s missing missing half the pieces. And so I think your point there that, you know, it’s not just the loss of total amount of habitat, it’s when it’s all caught up. And especially with roads. We see that occurring, you know, in many areas. So.
Yeah, I think that’s a great figure for visualizing this concept. And so I was excited to talk about this paper, because I think it’s really important for our students to read this paper for two reasons. One is just a great concise review of these large scale long term studies of the impacts of habitat fragmentation on species persistence and species richness and that All these other factors associated with with biodiversity loss. And I remember this this article didn’t exist when I was in graduate school. And I remember kind of trying to read like 50 papers on this topic and synthesize them in my own mind for my comprehensive exams. And I think what you end up doing is focusing on, like the nuances and the differences between these studies. And so you kind of like lose the forest for the trees and thinking like, there really is a consensus here. So I think that’s why this paper is so important. And not only did they summarize the findings of these different studies, but they did a meta analysis, which means that they took the data from all these different studies and re analyzed it so they could show consensus amongst all of these different studies of different ecosystems and different timescales and then size scales. So
so yes written this review paper. Had you thought of it back then? Oh my god.
idea I would have been published in graduate school.
Yeah, I needed like 20. co are the co authors like they have though. Yeah, that’s the
problem that these these really well thought out. Well done. Review pair papers require like 20 individuals in the tops of their field who have been studying this for decades. I do think it’s something that our students can think about when they’re doing their synthesis papers and review papers. But I’m not just to summarize what all of these researchers have done, but to think of the literature as something you can ask a question, a new question of, and maybe you don’t get to the point where You’re doing a whole new analysis of the data for many articles, but you can look at a different scale or just ask a new question that the original researchers weren’t asking.
Yeah, this this one. And what I think it also highlights these great long term research studies that have been going on for decades. And they’re manipulative or experimental studies, not just, you know, looking at existing forest fragments. But they actually like went in and manipulated these areas using lots of puncture funding money, National Science Foundation and other groups. But that that by doing that, by taking that experimental approach, they are able to control for all these other variables in and for most scientists, you know, come up with results that are low considered more rigorous, because you’ve actually just manipulated cut, you know, all the all the trees and created these fragments of varying sizes that are replicated, and then you’ve analyzed them for, you know, many, many years. I know, the seventh author on this paper, Thomas Lovejoy. He’s actually going to be coming to Cincinnati Zoo and spear barrows lecture. So we’re going to we’re going to be streaming that and recording it for for dragon fly students, as well. So that’s very cool. There’s some other huge names in this field on this paper in terms of the authors. And I know that Thomas Lovejoy his his thing, his particular project was the conducted in the Amazon and was the minimum critical size of ecosystems project. So, in the Brazilian Amazon, and I looked this up and I found out that since it started in 1979, it’s resulted in 562 publications. Yeah. thing. And 143 dissertations and theses.
Yeah, I am.
When I was in graduate school, I was really interested in the biological dynamics and force pregnant study and then head on actually came and spoke at UGA. He I think he’s a graduate of UGA. And there there are two talks that I went to in graduate school and I think the one by the DOD was one of the two that I mean, there were only two facts that I went to sorry, are the most influential and one of them was the the God because I just left that talk thinking like, Oh, this is what science can be, you know, like, if you have, you know, long term funding and the opportunity and that you can actually answer these questions and ecology because so often we end up kind of nibbling around the edges of questions. And we do observational studies where we can’t, you don’t have controls or replicates or baseline data, and then we can’t control those confounding variables you’re talking about. And we just, we look at correlations and argue about how to interpret them. Or we can do really small scale studies, like looking at the community inside of a picture plan, and which is really cool. But, you know, how does that scale up to the massive ecosystems that we live in, as far as their complexity and size So, yeah, I think as a graduate student is like, oh, if you have funding, you can actually answer these questions.
let’s see. Um, so I mentioned they did a good job reviewing kind of the history of these massive large scale long term studies. And you already mentioned the early ones by Lovejoy and all that group, where they’re looking at persistence and immigration between patches and really the the consequences of fragmentation and then the Savannah River site stuff, which was a lot of DoD and that group they looked at, okay, we know this is a huge problem. Can we create corridors and improve connectivity? And because the size and shape of the court or matter and and so there’s that that whole phase of these studies and then more recently they’re looking at synergies with climate change and land use and invasive species and I guess they mentioned the magnetron study in France, which I’m not very familiar with, but apparently they’re able to control temperature and moisture and all these other factors while also looking at fragmentation which is pretty amazing.
Yeah, that’s I always love the name of the meta Tron and it
just sounds so of course, it makes me think of transformers, things like that.
But ya know, I would imagine more of these are going to try and get into and it would be really expensive but to find ways to manipulate co2 And temperature and moisture regimes and things, perhaps in using
like, you know, different enclosures and things.
But yeah, I mean, one of the things I found most alarming about this paper was just their statistic about
you know, what was it 20%
of, or sorry, 70% of remaining force is within one kilometer of the forest edge. Yeah. And I think it was maybe 20% or so was within 100 meters.
And then showing that
essentially just getting it fragmentation through time and where it’s going to be happening the most little bit
and that’s something I thought a lot about when them when Looking at giant panda habitat is that, you know, if you look at a certain scale, there’s a certain amount of habitat. But then if you zoom in and look at the different patches are so tiny. It’s really disturbing. You know how each of those patches couldn’t really support like one panda. So
yeah, what what how much? I would think pandas would need an enormous home range, like, Dude,
it’s not as big as you would think. Their home range is only
I don’t remember exactly, but it’s not as big as you would think. But, um, these patches are actually smaller than that. So I think because they’re not predators, the habitat, the home range isn’t as big as you would think. But, um, as you know, compared to like a black bear or grizzly bear or something
Yeah, herbivores are going to need smaller patches than omnivores or predators. So that makes sense. They just did a good patch of bamboo.
What What I liked about this study that was fun, you know, we’re talking about scales is just the variety of scales of these from the mass fragmentation study, which was just really small, all the way up to the Brazilian study, which was big. And so that was really interesting to me. And one thing that this paper made me do is want to learn more about all the different projects. Yeah, like, Oh, what is this walk? I haven’t heard of the walk. Well, yeah. And so what is Walk walk in here? So who are the people behind it to you know, because we know that who’s behind some of the Brazilian work and the coos behind a lot of the Kansas work? Do you guys know the scientists Just
I don’t know. I’m not as familiar
with our Yeah, cuz you know that when I first saw it, I thought it was maybe some of the work by like Tillman, but he’s not in Kansas, but it looks just like his studies. So yeah, I was interested to find out sort of who started them what they’re about where they are, but I guess I might have to read 500 papers. But it would be really cool. And maybe I haven’t looked in the literature, but to look at is there like a review paper of here’s what we know from the biological dynamics, Brazilian study on fragmentation, summarizing all all the stuff we know, there’s probably some technical reports out there, but I’m wondering if there’s, you know, some reviews because that’s what I really wanted to know. And
he did a good one with the biological dynamics one after 20 years.
So we’ve been in like late 90s early 2000s There is a pretty good review paper but then you’re right there’s all these other studies I don’t think have had necessarily review papers on them and Megatron manager
yeah and i the last one I just because I love moss and I love like little patches of things like I did like looking in my backyard and we’ve got these patches of moss and my wife was like we were laying down wood chips in some areas and she’s like do not do not cover this moss
was like oh I’m right there with you I’m not touching them awesome love it.
But like how different species react to different scales and I there is a biologist, spider biologist I knew who was basically like yeah, you know, a lot of spiders like they basically will have like one meter radius if they act like little hunting territory if they’re like a like a wolf spider. Some of the smaller species of wolf spiders that live in tropical areas, like when you shine your headlight, and you see all their glowing eyes, looking back through. And when I first did that, I was just like, blown away. I had no idea there were that many spiders. This was in Belize. But no, it was like they were all distributed. Like, each of them had their one meter, like it was not random at all. And you could just see how the ecosystem for them was operating on this totally different spatial scale,
So anyway, that’s kind of just an aside, but yeah, I mean, what a way to spend your life and your life’s work on these long term projects and, you know, learning about the effects of fragmentation and habitat loss. I think it’s pretty, pretty amazing. Um, Rama, do you have anything else or Kendra on this article before we sort of switch gears,
I guess, just to summarize You know, I mentioned that there’s a lot of noise and all this data that when they’re able to look at consensus and do this meta analysis, they showed that habitat fragmentation reduces species persistence, species richness, nutrient retention trophic dynamics and movement of species across the board and it was you know, consensus is very clear once you get rid of some of this noise and take the time because there are all these lag effects so, you know, at first they would show oh well butterfly species actually increase for you know, five years after he fragments something and but if you look at the long the long term, and those patterns really solidify into loss of loss of species.
Yeah, lag times totally freaked me out because just like, whenever I start feeling optimistic, and I’m like, okay, we still have black rhinos, you know, still got them in there’s like 5500 left and their, their populations has actually been in creasing slightly over the last, you know, few years. And then I’m like, okay, but in 500 years, yeah, what’s the likelihood they’re still here, you know, when when you’re down that low and your habitats been altered that much, you know, it just seems like that longer term. outlook is pretty, pretty bleak. But
and I think that it gets to your point about the passenger pigeon that like how could you imagine it would ever go extinct? You know, if there’s something that can fly away, how could you kill every last single one of them, but they’re gone?
Yeah. Yeah. And I think it actually I’m guessing with passenger pigeons. It was a little bit of the alley effect. Yeah. Which means we will talk about with with Kendra’s article because I think they talked about it a little bit. But so let’s let’s switch to that one, which is the Brooke at all 2008 article on the synergies among extinction drivers under global change. So yeah, Kendra, what do you have to say about this one?
Yeah. That was the perfect segue to you know, like speaking of bleak
So, you know, this was a good review paper kind of looking at extinction, what’s causing extinction. And they’re kind of saying, okay, we know all this stuff is causing extinction. If we look at table one in here, you know, we know all these things about what’s causing mass extinction. What’s what humans are doing. All of these different things. These are what we now we know the four big players. I never heard this term before. The
word devils are
for you. Forget I wrote it down here the evil quartet
diamond came up with the main four things that are causing extinction and some of the details about them. So that quartet is over exploitation, habitat destruction, and of course, the fragmentation that we just talked about sort of falls under their invasive species and chains of extinctions. And that also relates to those trophic cascades and sort of what we talked about with the chestnut right that other things probably went extinct when the chestnut went extinct
So, you know, we know all these things about extinctions, but what we don’t know is how they interact. So what happens when you have all of them occurring or some of them occurring and you know, reality Is that’s usually the case. What happens when they interact? And so you know, the fact is it’s not just additive. So you don’t have you know, 10% extinction caused by this and 10% reduction by this. When you put the both together, it’s 50% reduction, it can act synergistically. I always tell my students, it’s two plus two is six. Yeah. And so, you know, because we do tend to look at these things. We have all these multiple threats coming, but you know, we sort of focus on them one at a time, instead of looking at them all together, more holistically, realizing they can interact, synergistically, non additively. And then to throw some more complexity and more, you know, have a bleak outlook. Let’s overlay climate change on top of it all. And let’s look and see, you know, what, how that interacts with all these because a lot of people haven’t looked at As much as they’d looked at the other causes of extinction in the past. So I thought it was a good review a little bit, you know, sort of bleak and a little bit overwhelming to think about all the different things, but I thought they did a good job explaining
what they were trying to explain.
Right. Yeah. Did I guess it should be an evil quintet? quintet now, with the climate change. Right. Right. And I guess, you know, you could quibble and be like, why aren’t you know, pathogens there’s or disease, but I guess that could fit under introduced species, usually. And there’s other ways this can all be grouped. But yeah, the general idea that if you got multiple stressors, you’re you. You could have a few things. I mean, they say, well, it could be additive. And it could also be non additive, right? It could it could be that You know, climate change just makes it so the generalist the wide ranging species are persisting, and maybe those are the ones that would be persisting anyway due to habitat loss. Right. So maybe, maybe it’s partially additive, I guess they call it. Yeah. Or
I think they call it partially additive. Yeah. So that’s sort of like, if climate change has the same effect as habitat destruction, they’re both reducing the range in the same way, then they’re not additive. It’s just gonna, you know, reduce it a certain amount.
Right. Yeah. And I, you know, I’ve thought about like positive feedbacks, which are not good. They’re not positive.
They’re not cool.
And not cool. They’re not good at all. But positive in the sense that they create more of the issue or the problem, right. So You know, if you have a species that is susceptible to climate change, and so it’s a, you know, maybe restricting its range, and then the habitat within its range is fragmented, right? So it’s getting even even more, which I think that point is made here. I know with climate change, just looking at climate change alone, like people talk about, well, the increasing temperatures can have a positive feedback loop on things like you know, if you have melting of snow cover in the Arctic, then more dark material is showing like soil or rock substrate, which absorbs more heat, which causes more melt, and then you have, you know, release of methane. So all of those things are it’s creating a cycle where there’s like more and more impact on climate change. So all these things Yeah, they can have any can go the other way have a negative feedback loop where, like with climate change, one of the things that’s been floated is the idea that with increased warming, perhaps there’ll be increased cloud cover, and therefore less sunlight radiation in certain areas and actually cause a cooling effect. So it could potentially mitigate some elements of warming, right. So I guess I’m just sort of perhaps divert a little bit off on a tangent there. But just the general idea that when you have multiple bad things happening, they can, they can counteract each other or they can affect in different ways.
And what else? I mean, there’s this MVP concept here that they have in the figure
which is the minimum viable population size, and they talk a bit about that. I don’t know if Kendra Yeti notes on that are
Yeah, not too much. I mean, that’s the magic number that everyone tries to find. And, of course, you know, beyond that you start to get into stochastic effects and extinction vortexes. That sounds pretty scary. where, you know, you sort of spiral down and extinction is accelerated, sort of once you hit that minimum viable population size. There’s a lot of issues with trying to find that magic number, of course. But yeah, they sort of put it here as your, as your, you know, Danger, danger, danger, don’t cross that line. You know, once your population gets small enough, you get all kinds of things like the Ilia effect, and more susceptibility to stochastic events. And, you know, genetic drift, all of those kinds of things happen that small, small enough population. So when you get to that point, it’s sort of the death knell for the species. So you’re trying to keep everything below that. threshold.
So what is we’ve talked about the effect? I mean, what do you how do you guys sort of think about that? And as to what exactly it is, I feel like it’s in some ways, it’s very simple. And in some ways, it’s kind of complex.
Yeah, so I mean, you know, briefly the Lee effect is you have to have a certain number of individuals, there’s, it’s against another threshold thing. You have to have a certain number of individuals for something important thing to occur. Usually, you know, successful reproduction, survival, right? fitness level. If you get below that, it might look like you have a lot of individuals you’re like, shoot, there’s a lot of birds out there, there’s still 400 but it turns out the birds need 500 out there to feel sexy and mate. If they see less than 500 they’ll just walk around and you know, never get on Tinder and find each other. So it’s kind of this threshold for, you know, Lex are a good example right in birds, where you have to have a certain number in a lack before, you know, everybody gets all excited and wants to mate with people with bird sorry
with each other
do you guys know of any other examples? Those are kind of the ones that I teach in my class for Lee effect is sort of mating rituals. I don’t
think of any offhand.
No, do you know aroma any that come to mind?
I mean, it just makes me go fishing that find each other through pheromones or something. Just they’re so far apart. They never detect those pheromones and environment to track each other down. I guess like
yeah, I’m like lonely George, the one of the Galapagos tortoise. subspecies that would be an extreme example of just you know, getting down to that point where you Yeah, you actually do not have anyone else to mate with. So there, there is no way you can continue your your fitness for the next generation is zero in that case, right? So I guess yeah, yeah. If you think about like, if there’s 2 million individuals of the species, and they drop down to 1 million, you may have like a 50% reduction in the average, you know, the number of individuals in the next generation, right? But then when you get below that threshold, you were talking about kandra. The decrease in the next generation output base precipitously drop off right because of that critical need, where they just can’t find each other for mating, or they don’t feel sexy enough, as you said, whatever pheromones and I wonder, you know, when the passenger pigeon I imagine something like that. must have happened, right?
It would have been hard for me to drop off in that way when I
write, I don’t know it as well as I should. Exactly sort of what I just know. It’s mostly overharvesting that, you know, led to the decline, but yeah, I did read some stuff that they were very social. So yeah, probably there was only effect because usually, you see that more in some social systems. Communication.
Um, what else from us? Yeah,
yeah, there was. There’s a couple interesting, you know, little things in here, a little nugget that I got that I didn’t know. The one being this dung beetle sample, which is pretty interesting where over hunting of mammals led to less dung beetles. And dung beetles are super important ecosystem service providers, where they recycle nutrients and then also Probably stop the spread of parasites by getting these done away. So you’re not exposed to any worms in there anything. So I thought that example was pretty interesting where you when you lose those, you lose the dung beetle and then you know, trees are affected.
Yeah, so that was a new one to me. I hadn’t thought about.
Yeah, and you you made that point really well, Jeff and ramas example of the American chess night and how like we think of it as the American chess not becoming functionally extinct are largely disappearing from these forests. We think of it as one species, but really, every extinction we can think of, you know, I’m sure also for the Kylie’s Thylacine, and for the passenger pigeon, there was probably dozens of unknown extinctions that went along with that, that we just haven’t fully understood. Whether it’s The parasites associated with those species or mutualists in some way.
Yes. For the passenger pigeon, they mentioned that perhaps a louse went extinct. That is specialized on the passenger pigeon. But good is that lice did not go extinct they found it in the 90s or something on another species of pitchers. Your use use parasite Yeah, all these smaller organisms you don’t even think about that when extinct with the you know, the bigger one because we tend to think of these charismatic species going extinct but all the little critters even the lowly louse, you know went might have gone extinct so it’s pretty interesting to think about, huh?
Yeah, they give that other example of the sharks, the large predatory sharks in top down control the size the last mo Bronx, Bronx which are the res skates in small show And then I guess when they’re gone, the three skates in small sharks increase to the levels that they eat up all the scallops.
So yeah, there’s
tons of these examples, but the I really like them is they’re just interesting to think about the ecology even though they’re kind of sad.
They also get a little bit into these large international agreements and things.
Right, is it that this one or actually maybe it’s the next one?
Maybe I fell asleep during that part. But yeah, no, I don’t think it’s, I think it’s yours.
Okay. Well, maybe we’ll jump into that. I feel like I saw some note here about them talking about one of the United Nations. You know, just the fact that it’s it’s important to study all these different factors. But yes, it’s definitely much more of a. So let’s let’s switch gears into this other article, the brochures at all 2014 Wildlife decline and social conflict. So so far we’ve just been talking about, like, what causes extinction or in dangermen, how it works together. And now this one really gets into how that affects humans. And I think it takes a different approach and focus than we tend to think of, I tend to think of, okay, a species goes extinct and how it affects six, you know, it’s sad, we can’t see that species anymore. There’s sort of a loss of the intrinsic value of that species to the world. But this one really gets into focusing on kind of the poorest people of the world who, when they’re living in these areas, of why Life depletion.
it necessitates them.
Sometimes leading into increasing exploitation of those species so creates this another positive feedback that is negative. And they really talk about some very interesting examples from pirates in Somalia who, you know, justify their rating of ships to protect the sovereignty over their offshore fishing grounds because other international ships come in to fish because they can’t get the fish quotas they need. So they come into Somalian waters. And then those people who were doing more local fishing also need income. And so they end up in this pirating situation and then link it to the drug trade and slavery and crime syndicates? So there’s just a lot here of tying social welfare, to wildlife loss that I thought was very unique to read about. What did you guys think of this? This article?
Um, I mean, I’m not a wildlife, like human dimensions person. So I definitely got a lot out of it. And it made me think of a lot of the studies looking at the relationship between climate change and conflict in the Middle East and Sub Saharan Africa that, you know, you have people who can support themselves and then climate change impacts their ability to do that, and then they get recruited by these extremist and it’s very, very bad.
Yes, good kyndra I thought this was pretty interesting. I’d never thought about the connections like, Yeah, I thought about like black market trade and like, you know, who’s making the money from that all the criminals and, you know, you think about all the crime movies you’ve seen. I’ve thought about that, but I’d never thought about with like fisheries collapsing, you’ve got a higher effort. And so you get child slaves. I never would have thought of the connection between, you know, dwindling wildlife and increases in child slavery. But it makes sense. It’s just you don’t often make those connections.
Yeah, they have that interesting figure there, which is like, you know, fish stock decreases. So, the Fisher, the fishermen have to increase their catch unit to catch per unit effort somehow, so they can actually Lee find cheap labor demand will increase, you know, just like you just said, and this sort of whole cycle that leads to food insecurity and poverty increases and all these things and violence and increases and in fact, there’s this quote by a single ease fisherman in this article that says, in 10 years time people will go fishing with guns, we will fight to fish, we will fight for fish at sea, if we cannot eat what do you expect us to do? Which I think is a great voice to have included in this article. I know people and a lot of dragonflies students and instructors, you know, feel very against poaching and very against hunting of endangered species. But you know, when you hear you’re starving and you don’t have much choices, you know, I think there’s it’s it’s way more complex. than simply being a bad thing. So I know like, I just read this article about rhinos and talking about black rhinos were earlier discussing others, you know, 5500 now, and Namibia, as a country has considered, you know, allowing just five of their growing population of rhinos to be hunted a year for $400,000 each. So that would generate $2 million dollars US and would fit within their what they see is as a projected growth rate could be maintained with that level of harvest. And it would have these huge profits that could really benefit conservation in the area. So
controversial issue, but I just sort of want You mentioned that.
Okay, I think there’s so much potential for putting the management of resources back into the hands of the people who are closest to it.
But then I also think there’s so much room for that to go wrong. And
it really needs to be a concerted collective effort and maintain a real long term. Because you can put management back into the hands of the people closest to that resource. And if they are feeling desperate, then they’re you know, they’re going to go move back towards overharvesting. So
yeah, I thought that was a great point of this article that they were really arguing for putting the control back in the people’s Hans and I think that I was just looking for this term and I, it’s something like eco colonialism. But it’s, I don’t think that’s quite what I’m thinking, yeah, but it’s this term that basically gets at the idea of all these international agreements, including, like the International Union for the Conservation of Nature, some of their guidelines and rules and different treaties, which conservation tend to think of as a very good thing, but they have also essentially exerted control over other countries resources. And when it comes down to it, I think this article starts to make that point that that may not be the best strategy. And they give the example also of Namibia, of these community cots, conservatories that exist in Namibia, where the people living there want the ability to harvest within reason. Some of the species that currently they are not allowed to harvest or sell products from So again, it’s it’s it’s an issue to think about But yeah, I think it’s there’s a lot there to to consider.
did you have anything else on this article?
No, not really.
All right. Well, I think we’ve covered them all.
A lot of a lot of different issues.
So I think we’ll we’ll wrap it up.
Any final over overarching thoughts you guys want to jump in and share takeaways you would consider
My, maybe this is too much of a discussion. But how do these three papers fit together? I think the first to do but I’m wondering why the third you know, I mean has to do with declining species, but it was really kind of a and I liked it. It was interesting, but it was kind of like coming out of left field, like what do you think? Why was this chosen?
Yeah, that’s uh, I kind of felt that to read so differently the other to fit it within the the parent, you know, they feel very academic. They feel very, you know, their research articles and then this one is, you know, it’s it’s published in a journal that I would have not, is not typically on my radar somewhere to read it has. It’s like a magazine article. It has this picture of this child. But I think it’s an important connection to not just think about it in that more academic sense that the other two articles kind of, you know, it feels problematic, certainly what they’re talking about, but this one for me, kind of just made it hit home in a different way. how this all affects the world and humans in particular.
And I, you know, the title of this discussion was, I think it was extinction and its consequences. And the first two articles are more like extinction and its causes. I think, you know, I guess you can think of consequences. As you know, extinction vortexes and our extinctions caused more and more extinctions. But from a human perspective, this last one
actually talks about consequences. Or humans. Yeah,
I liked it. It just, you know, felt diff Hmm, why did they pick that
Yeah, you wouldn’t, I mean typically hear discussion of like, crime syndicates and these groups in Africa like ganja weed and Lord’s Resistance Army and Boko Haram. And these those headlines right are almost always focused on human exclusively on human issues. Right. I think this is one of those cross cutting articles that hits a couple different disciplines and areas of thought so yeah, I think but it’s a great question, because it’s, it’s something that sometimes is missing. I feel like from the pure ecological literature, in my opinion,
I think students will have some good conversation around this too. So I think it was a good choice.
All right. Well, thank you both for joining and talking about this. And thanks for those of you listening in. We hope this is useful to you in the comments, In the, you know, written asynchronous discussions. We hope you’re enjoying these conversations. And we’ll look forward to doing this again soon. All right, take care. Bye bye. Okay, so it’s Ken Madison again. I hope you enjoyed that discussion. And as promised, I did want to share some of the feedback we’ve been getting on these podcasts just so you know how your fellow students are reacting. I just have two comments to read. And these are quite positive. But again, we’re open to all sorts of feedback. So feel free to let us know where you’re listening. What you found interesting, any sort of unique things about invasive species or extinction or whatever it may be that you’re thinking about, and you can send those to me again, it matters KC, me TTS, Casey at Miami. Oh h.edu or at my phone number 513-529-0837. So the first comment is from Natalie. And she just said, Hello, I just want to provide some positive feedback about the IBD podcast, I found the first discussion very helpful to my comprehension of the articles. And I look forward to hearing more throughout the semester. So thanks, Natalie. That’s awesome. This is all about universal design, which is a term in education and pedagogy that basically involves reaching out to people in various formats, because we all learn in different ways. So it’s nice to hear that this is eating in your comprehension of the articles. And then we got another email from Carrie, who said, I just want to drop you a line letting you know that I am loving the podcasts. I’ve never really listened to any before. Too many choices. Not enough time. So this was new to me. First and foremost, I really appreciate being able to hear the instructors interpretations and discussion of the articles. Sometimes I’ll gloss over something I think may not be important or miss something completely, but it’s brought up and discuss in detail giving me a more thorough analysis. Sitting. Second, it’s really convenient. I found that I can’t do anything else while listening because I don’t want to miss any part of the conversation. But to be able to listen on my phone computer or in the car is wonderful. And last, it’s really great to hear everyone’s voices to match up with their photos. It shouldn’t matter. But somehow it does. Hearing the instructors tones and inflections really gives the listener a better sense of intention, and provides greater impact to the meaning of their words. I’ll leave it at that. But let me let everyone know that their work is appreciated that they have a fan in me. So thank you so much, Carrie, that is wonderful to hear. We really appreciate the positive feedback. And yeah, well we keep exploring different things. dragonflies really unique in that we have so many wonderful students all over the country and the world. And we want to find unique ways through technology to reach out in a personal and convenient manner.
So thanks again and we’ll look forward to hearing from others down the line if you have the time to let us know Have a great day everyone. Bye