Speaker 1: Welcome to Stuff to Blow your Mind from how Stuff
Speaker 1: Works dot com. Hey, welcome to Stuff to Blow your Mind.
Speaker 1: My name is Robert lamp and I'm Joe McCormick. Hey, Robert,
Speaker 1: I've got a I've got a quiz question for you.
Speaker 1: All right, quiz what do you think is the animal
Speaker 1: out there in the world that humans are the most like?
Speaker 1: M hmm, Well, I mean we're we're so unlike all
Speaker 1: the creatures, but I mean one obviously turns to the
Speaker 1: primates for our closest evolutionary relatives. Yeah, I would say physiologically,
Speaker 1: if you look at comparative anatomy, and of course genetically,
Speaker 1: we are the most similar to primates like chimpanzees and binobo's,
Speaker 1: and they actually are known to be our closest relatives
Speaker 1: in the animal kingdom. But I think if you look
Speaker 1: at humankind in a different light, if you don't just
Speaker 1: look at the individual body plans and compare one individual
Speaker 1: to another individual, but if you compare the entire species
Speaker 1: ecological and trophic profile as a whole population, you can
Speaker 1: make a very different case. We're the most like ants,
Speaker 1: and we became more like ants starting around ten thousand
Speaker 1: and maybe thirteen thousand years ago. Before this time, I
Speaker 1: would say, there's really no way to compare us to
Speaker 1: ants at all. We just weren't very antlike, except maybe
Speaker 1: that you could say we were a social species. But
Speaker 1: you know, maybe ten thousand to thirteen thousand years ago
Speaker 1: humans first started practicing plant and animal agriculture, and over
Speaker 1: the years more people began to transition from a nomadic
Speaker 1: hunting and gathering way of life to a settled agricultural
Speaker 1: way of life. And of course the introduction of farming,
Speaker 1: we know the story. It changed everything. It allowed for
Speaker 1: surpluses of food resources, specialization of skills, education, writing, construction, invention,
Speaker 1: and so on. And because all of these processes were
Speaker 1: made possible by keeping people and resources close together with
Speaker 1: continuous interconnected access to one another, this meant the birth
Speaker 1: of cities. And I would say ever since then, the
Speaker 1: construct of the city, the idea of the city as
Speaker 1: a technological thing and as a social organizing principle, has
Speaker 1: been one of the biggest influences that has changed the
Speaker 1: way human beings relate to the earth. Now, we're all
Speaker 1: pretty familiar with this story of of urbanization from a
Speaker 1: human point of view, but from a biological or ecological
Speaker 1: point of view, It is an extremely strange and interesting
Speaker 1: thing for us to do. And it's also extremely similar
Speaker 1: to what ants do when they form colonies and build
Speaker 1: ant hills. It is yeah, when you when you start
Speaker 1: thinking about it, this this artificial habitat that they can
Speaker 1: they construct to live in and in, you know, in
Speaker 1: in in in some cases, grow their food in, cultivate
Speaker 1: their own crops. Yeah, almost all creatures on Earth adapt
Speaker 1: to their environment. The environment is one way, and the
Speaker 1: animal over time evolves to be a best fit to
Speaker 1: the environment around them. But humans and ants and some
Speaker 1: other creatures you could argue, like bees and some other
Speaker 1: use social insects, termites to some extent, don't adapt to
Speaker 1: their ecosystem as much as they build an ecosystem for themselves.
Speaker 1: They engineer their own environments in their own ecosystems, and
Speaker 1: of course, in both cases ant hills and human cities,
Speaker 1: these ecosystems are not hermetically sealed off from the rest
Speaker 1: of the world. They're poorous and connected to the rest
Speaker 1: of the world. And what this means for ants, of course,
Speaker 1: is that they have entire classes of organisms that have
Speaker 1: specifically evolved to thrive within the ecosystems created by the ants,
Speaker 1: the same way that a fox or wolf, spider or
Speaker 1: any other creature would thrive within its natural environment. There
Speaker 1: are organisms that that have evolved to thrive within the
Speaker 1: ant engineered environments, and these organisms are called myrmica files. Yeah. There.
Speaker 1: Then there are a number of different species that the
Speaker 1: one could spend time with. Here, Uh, a couple that
Speaker 1: that came up from me though, Uh, there's one. Uh.
Speaker 1: This is an example of research before the p Favieri deetle.
Speaker 1: So it uses a complex dance of both chemical and
Speaker 1: auditory mimicry to convince the ant population that it's one
Speaker 1: of them, even as it crawls in into their abode
Speaker 1: and feeds on their larva and benefits from the colony's protection.
Speaker 1: But as Carl Zimmer highlights in his New York Times
Speaker 1: piece on a study concerning these beetles, the deceptive beetle
Speaker 1: may even mimic the queen from time to time in
Speaker 1: order to receive royal treatment, but it otherwise knows to
Speaker 1: leave the queen unharmed. It doesn't seek to decimate its
Speaker 1: host colony, but rather to thrive within it through perfect mimicry.
Speaker 1: Uh and uh. I explored this, by the way, originally
Speaker 1: because I was interested the Monster from John Carpenter's The Thing,
Speaker 1: because one of the ideas that is explored in the film,
Speaker 1: and I think also in like a comic book sequel,
Speaker 1: is that if this thing gets gets out, if it
Speaker 1: escapes from this frigid base, it's going to just decimate
Speaker 1: the world in no time. Right, it will mimic all
Speaker 1: life forms and just take over the entire planet. Right.
Speaker 1: But would it necessarily do that? Right? I mean, I mean,
Speaker 1: you can certainly make a case that it's an alien contamination,
Speaker 1: So who knows what it would do to to to
Speaker 1: what is to it an alien ecosystem. But I think
Speaker 1: if we look to examples like this from our natural world,
Speaker 1: we can we can see that, well, maybe it wouldn't
Speaker 1: necessarily overrun the planet because it needs to live at
Speaker 1: harmony within the host ecosystem. Yeah, it needs an ecosystem
Speaker 1: to survive off off of. It can't become the whole
Speaker 1: ecosystem itself. Yeah, So it's they're going to be essentially
Speaker 1: self imposed limits on what it will take over and destroy. Now,
Speaker 1: that's far from the only example of mermai else that
Speaker 1: have evolved specifically to survive and thrive within the environments
Speaker 1: created and maintained by ants. There are thousands more, right,
Speaker 1: One that I ran across that was interesting is the
Speaker 1: oak blue butterfly. So these don't reside really within the
Speaker 1: colony so much, but the butterfly larvae may chemically mimic
Speaker 1: or camouflage themselves and be accepted by the what are
Speaker 1: sometimes called the plant ants on their host plant, the
Speaker 1: ant plant, or macaranga as it's called. So essentially what's
Speaker 1: happening here is the chromato gaster ants. They nest in
Speaker 1: the plants hollow stems and then attack anything that climbs
Speaker 1: or lights upon their domain, except for the oak blue larvae.
Speaker 1: And this is presumably because it has an evolved a
Speaker 1: defense that tricks the ants into thinking it's okay for
Speaker 1: it to be there. Yeah, so there's protection within the
Speaker 1: ants domain, even if ultimately there's no more dangerous place
Speaker 1: to be than within an antstone. Right, there's protection if
Speaker 1: you have some kind of evolved defense to sneak through
Speaker 1: the city walls and say, okay, I'm part of this colony.
Speaker 1: Now nobody noticed that I'm not an Aunt. Yes, hello,
Speaker 1: fellow ants. Now, Aunts have been engineering their own ecosystems
Speaker 1: for millions of years, right, so there has been a
Speaker 1: lot of time for these mermica files and these creatures
Speaker 1: that infest ant colonies and other AUNT controlled environments to
Speaker 1: very tightly hone their their evolved traits, right that, There's
Speaker 1: been a lot of time for them to do this. Humans,
Speaker 1: on the other hand, have only been engineering their own
Speaker 1: environments for much much less time, just thousands of years.
Speaker 1: But nevertheless, our human ant hills seem to be in
Speaker 1: the early stages of developing Mermica files of our own,
Speaker 1: except they wouldn't be Mermica files, they would be creatures
Speaker 1: of the city. As we continue to engineer environments around
Speaker 1: the concept of the city, more and more forms of wildlife,
Speaker 1: we're beginning to show marked adaptations and eventually heritable evolved
Speaker 1: traits for specifically surviving in human urban landscapes. This is
Speaker 1: urban evolution, and this is gonna be our topic for today.
Speaker 1: This is actually going to be the first part of
Speaker 1: a multipart episode that we will continue to explore just
Speaker 1: because there's so much interesting stuff to talk about, but
Speaker 1: it's going to be focused on wild organisms evolving to
Speaker 1: survive and even thrive within the ecosystems that humans have
Speaker 1: engineered for themselves. And we should go ahead and mention
Speaker 1: that we've been wanting to do this episode for a while,
Speaker 1: but recently a book came out on this topic and
Speaker 1: this became one of our major sources for this episode.
Speaker 1: It's a book but the Dutch evolutionary biologist Minnow Skill Tausend,
Speaker 1: who is a researcher at the Naturalist Biodiversity Center, which
Speaker 1: is a museum in Leiden, Netherlands, and the book is
Speaker 1: called Darwin Comes to Town. It was just published by
Speaker 1: Pikador just recently. Yeah, I'll include a link to this
Speaker 1: book on the landing page for this episode of Stuff
Speaker 1: to your Mind dot Com. I want to note that
Speaker 1: the cover illustration is fabulous because you have this this
Speaker 1: drawing of various animals scaling a zigaratte that it's formed
Speaker 1: of all these buildings and skyscrapers. Yeah, it's it really
Speaker 1: captures the spirit of the book. I appreciate a good
Speaker 1: cover illustration because so many books have bad cover art. Now, yeah,
Speaker 1: it seems to be a dying art form. Here's my
Speaker 1: cry out there. If you're a publisher of science fiction
Speaker 1: or fantasy or something like that. Stop going with the
Speaker 1: stop going with the stock art. Get those original illustrated
Speaker 1: covers back. Those were great. Yes, And I do not
Speaker 1: want to see another minimalist like mock up of a
Speaker 1: movie poster or a book cover. I'm done with that.
Speaker 1: I want I want to a full visual experience. No.
Speaker 1: Back to the subject. Okay, So Skill Tolls and actually
Speaker 1: himself makes this comparison between human cities and ant colonies,
Speaker 1: and the subsequent comparison between mermenicaphiles and the organisms that
Speaker 1: have come to thrive in our cities. And I think
Speaker 1: it's a really good comparison, except one difference is that
Speaker 1: our cities are actually and much more vast and varied
Speaker 1: landscapes than the complex environments that ants create. Right, yeah,
Speaker 1: I mean you look at something like say New York City,
Speaker 1: right You have the sort of concrete jungle regions of
Speaker 1: the city. You have an artificial um wilderness in its center.
Speaker 1: You have essentially mountains made out of steel and glass
Speaker 1: that alter the flow of air, that alter the weather itself.
Speaker 1: You just have so many different elements going on to
Speaker 1: warp the natural world into a new form. I tried
Speaker 1: to make a short list of just some of the
Speaker 1: ways that cities are fundamental departures from what the natural
Speaker 1: landscapes around them are like. And I know I didn't
Speaker 1: capture everything here, but here just the things that occurred
Speaker 1: to me in our research. One of them is habitation surfaces. Right,
Speaker 1: not many complex organisms can live on flat concrete without
Speaker 1: soil or vegetation. That that's not an environment that occur
Speaker 1: is all that much on Earth. And when environments kind
Speaker 1: of like that do occur, there aren't a whole lot
Speaker 1: of organisms that inhabit them. So much of the plant
Speaker 1: and animal life in cities is isolated to or based
Speaker 1: in urban islands of vegetation. So they're gonna be things
Speaker 1: like parks or small undeveloped areas, or urban trees or
Speaker 1: yards or gardens or grassy street medians. We look at
Speaker 1: these spaces in our urban areas as kind of blank, right,
Speaker 1: Maybe not parks, but a lot of these other things,
Speaker 1: like the grassy median between two sides of a highway. Yeah,
Speaker 1: we think we might think of that as a place
Speaker 1: that is empty, but really, like that's the only place
Speaker 1: in your field of vision where there is non human
Speaker 1: life taking place at any like real degree. We look
Speaker 1: at those places sort of like the margins of of
Speaker 1: a page, like that's where nothing's going on. But yeah,
Speaker 1: that is in fact like a hot spot. It's a
Speaker 1: hotbed of life and activity that is surrounded by these
Speaker 1: dead rivers of asphalt, so many feral cats just whooping
Speaker 1: it up in there. But there is so much more
Speaker 1: than that. So okay, that's the obvious habitation surfaces. But
Speaker 1: then there is climate. Actually, the climate of a city
Speaker 1: is generally different than the climate of the surrounding area.
Speaker 1: We've talked before on the podcast about the idea of
Speaker 1: the urban heat island effect and urban rain. Uh. The
Speaker 1: the material properties of cities in the way they absorb
Speaker 1: and reflect light and retain heat actually affects the temperature
Speaker 1: and the weather within the city, usually leading to these
Speaker 1: situations where in the middle of a city it's a
Speaker 1: lot hotter than the surrounding countryside is on the same day.
Speaker 1: An obviously huge factor that makes a city different than
Speaker 1: the surrounding environment is what types of food resources are available,
Speaker 1: because it's going to be completely different nutritional profiles. Yeah,
Speaker 1: outside of the city, a bird has to you know,
Speaker 1: hunt around for its h its food, but inside the
Speaker 1: city it can just fly into at home depot and
Speaker 1: just aisle upon aisle of food awaits it. Now, I
Speaker 1: wonder if for birds, home depot eventually becomes a sub
Speaker 1: city within a city, where birds will evolve their own
Speaker 1: populations within the home depot over that's kind of frightening.
Speaker 1: I imagine like large prehistoric carnivorous birds roaming the home
Speaker 1: depot picking off humans that are a little too little
Speaker 1: too picky in which soil they're going to purchase for
Speaker 1: their home garden. Here's another one. You've got very different
Speaker 1: kinds of threats in human created environments than you do
Speaker 1: have an unspoiled natural landscapes. You have environmental threats, human threats,
Speaker 1: and machine threats. I mean, think about try to put
Speaker 1: yourself in the mind space of like a fox or
Speaker 1: a coyote or raccoon or something, and you're living in
Speaker 1: a place where there are these giant mechanical predators constantly
Speaker 1: plowing through the city back and forth at high speeds,
Speaker 1: and they will kill you. But also they don't really
Speaker 1: seem to chase you, and so it's it's you're not
Speaker 1: evolved at all to deal with this kind of situation. Yeah,
Speaker 1: the Frogger game, that is life for an animal in
Speaker 1: the city. Yeah, cars as predators. It's a thing that's
Speaker 1: hard to direct wrap your mind around. If you're a fox,
Speaker 1: then of course there's a totally different chemical environment than
Speaker 1: there is in in unspoiled nature. So you've got pollutants.
Speaker 1: Of course, you've got the byproducts of industry and all that.
Speaker 1: But then you've got things that people wouldn't even often
Speaker 1: tend to think of, Like, how about if you're in
Speaker 1: a northern city, what chemically you might you do to
Speaker 1: alter the surfaces of the city during the winter. I'm
Speaker 1: thinking about spilled hot chocolate for starters. I guess that's
Speaker 1: a good one. But how about salting the roads? Oh
Speaker 1: my goodness, I mean, yeah, millions of pounds of salt.
Speaker 1: You turn it into basically a big salt lick of
Speaker 1: death exactly. Yeah, so you're you're fundamentally altering the chemical
Speaker 1: profile of the surfaces that these animals dwell upon, and
Speaker 1: suddenly all this runoff water that would normally be fresh
Speaker 1: water become salt water. And yeah, it's totally strange. Here's
Speaker 1: another one. The darkness regime, completely different in cities than
Speaker 1: it is in a place that hasn't been colonized by
Speaker 1: human beings. That that's a that's a great one. I
Speaker 1: mean that in roads are situation like light pollution, and
Speaker 1: in roads, of course are everywhere. The roads crisscross human
Speaker 1: habitats wherever they occur, and and you know, invite death
Speaker 1: for anything that dares to cross it. And then of
Speaker 1: course we we've all heard accounts of how dangerous artificial
Speaker 1: lighting can be uh into various natural habitats, including beach
Speaker 1: habitats for turtles that are returning from the ocean to
Speaker 1: lay their eggs. Yeah, and of course a big one
Speaker 1: being for insects. The way light affects insects is crazy.
Speaker 1: I mean, there's this thing that's the vacuum cleaner effect
Speaker 1: that Skill tous And talks about in his book, where
Speaker 1: you put say a service station out by a dark
Speaker 1: highway in the middle of nowhere, and it's got lights
Speaker 1: on at night. And what this is going to do
Speaker 1: is act like a vacuum that just sucks in insectual
Speaker 1: life from the hire surrounding countryside for a period of
Speaker 1: time until it's killed so many millions of insects that
Speaker 1: Eventually the density around it just kind of drops off,
Speaker 1: and then it stops happening for a while, and then
Speaker 1: you have the city which just has that going on
Speaker 1: all the time. It's just a center of artificial light
Speaker 1: all night. Now, that's by no means all of the
Speaker 1: ways that cities change the environment from the natural environment,
Speaker 1: but that that's a handful of them to get you
Speaker 1: thinking about the ways that these techno beasts that we
Speaker 1: inhabit that feel very natural and normal to us are
Speaker 1: are aliens sci fi environments for animals that are designed
Speaker 1: to live in a meadow or live in the forest
Speaker 1: or something like that. And yet at the same time
Speaker 1: we know for me and Malcolm that life, uh finds
Speaker 1: a way that's right and find a way it does.
Speaker 1: And that is what we're going to be focusing on
Speaker 1: for the rest of the episode today is many of
Speaker 1: the fascinating ways that urban life affects wildlife and that
Speaker 1: wildlife apps to it or fails to adapt to it.
Speaker 1: All Right, we're gonna take a quick break and when
Speaker 1: we come back, we will dive right into the topic.
Speaker 1: Thank alright, we're back. You know, Joe, we live in Atlanta,
Speaker 1: and certainly especially the portion of Atlanta we reside in
Speaker 1: is is far from a like stereotypical concrete jungle. We
Speaker 1: have a lot of green trees around, a lot of
Speaker 1: these little noman zones of of of of built up
Speaker 1: weeds and vegetation for things to live in. What are
Speaker 1: some of your your favorite wild animals that you've encountered. Yeah,
Speaker 1: Landa actually is sometimes known as the city of Trees,
Speaker 1: and I like that about it. I mean, it can
Speaker 1: be a problem if a tree falls on your house
Speaker 1: or something, but otherwise it's very nice to have all
Speaker 1: this urban greenery that we do have. But yeah, as
Speaker 1: far as urban wildlife goes, I don't know. I mean,
Speaker 1: there's a lot just in my backyard. Like our our
Speaker 1: dog Charlie, he loves to chase the squirrels in the backyard.
Speaker 1: And there was one night not too long ago, when
Speaker 1: he's not a barker, he'dn't bar much, but we let
Speaker 1: him out in the backyard one night and suddenly he
Speaker 1: started barking, and we're like, what's going on? And we
Speaker 1: went out to get him and we realized he was
Speaker 1: in a standoff with an opossum. It's perched up on
Speaker 1: the fence and not moving. It just was frozen and
Speaker 1: staring at him and making the face. And so we
Speaker 1: got him inside and the possum never moved. We looked
Speaker 1: back out the window like a while later, and it
Speaker 1: was still in the exact same place, hadn't moved from
Speaker 1: the spot. And I think about adaptations when I see
Speaker 1: stuff like that. So, Okay, you've got an urban opossum
Speaker 1: and that maybe is getting some tasty trash morsels living
Speaker 1: in the city like this, but it's also got a
Speaker 1: deal with dogs and backyards and people and animal catchers
Speaker 1: and cars and all this stuff that threatens it. And
Speaker 1: for some reason, it's it's evolved response to this is
Speaker 1: freeze and make the scary face. Why does it do
Speaker 1: that and does that usually work or what? What was
Speaker 1: that traite evolved as a solution to. You know, the
Speaker 1: backyard division of things is really interesting because it does
Speaker 1: create these these little sequestered zones where that are protected,
Speaker 1: but each one also may contain its own localized predator
Speaker 1: in the form of a dog or even you know, cats,
Speaker 1: which I guess are gonna be less restricted by the
Speaker 1: fences little enclosures with monsters in them. Yeah, it was
Speaker 1: very recently It was just last week actually that I
Speaker 1: heard this rucus bird rucus in the backyard, and I
Speaker 1: went to check it out because I'm thinking about what's
Speaker 1: happening in cat that there's a maybe a feral cat
Speaker 1: back there messing with some birds. I look back there
Speaker 1: the birds were agitated because a wild turkey was in
Speaker 1: my backyard. Yeah, so good, I know. It's it's really
Speaker 1: kind of a holy experienced to see a creature that's
Speaker 1: ultimately so large. If you've not seen one there, it's
Speaker 1: a far different animal than the like the Thanksgiving turkey,
Speaker 1: but it is it is still a big critter and
Speaker 1: seeing it hop up there on the fence and then
Speaker 1: uh disappeared into the next yard was pretty pretty awe
Speaker 1: inspiring for me. Yeah, my parents actually in Tennessee sometimes
Speaker 1: get turkeys in their yard. Well, you know, I don't
Speaker 1: know about everyone else, but one animal that instantly came
Speaker 1: to mind from me when thinking of of creatures that
Speaker 1: thrive in an urban environment is the noble trash panda.
Speaker 1: The raccoons. Raccoons, Yeah, they've you know, it makes sense
Speaker 1: because raccoons, they've thrived in North America for at least
Speaker 1: two point five million years or at least we know
Speaker 1: that it's Procyon genus was well established here by that point,
Speaker 1: with its ancestry reaching back a good through thirty seven
Speaker 1: million years. But their success is due largely to their flexibility.
Speaker 1: Oh yeah, there's sort of a jack of all. Yeah, yeah,
Speaker 1: they they have They have teeth for both the shearing
Speaker 1: of meat and also expanded molars for crushing. They also
Speaker 1: have these incredibly sensitive hands which can be used to
Speaker 1: manipulate objects and feel without loss of sensitivity for food
Speaker 1: and chilly stream beds. You know, that makes me wonder
Speaker 1: Sometimes our listeners have asked this fun question before. It
Speaker 1: was like, if humans disappeared, what would be the next
Speaker 1: creature on Earth to like assume the sort of intelligent
Speaker 1: civilization mantlepiece. And of course you want to say, well,
Speaker 1: probably great apes or something. Uh. Some people want to
Speaker 1: say dolphins or whatever. But you could say, well, I
Speaker 1: wonder about raccoons. They've got hands that are really kind
Speaker 1: of a hand alike. They can manipulate objects. That seems significant. Yeah,
Speaker 1: And I was when I dived a little deeper into this,
Speaker 1: I was really impressed by just how sensitive their hands are.
Speaker 1: So I want to read a tidbit here. This is
Speaker 1: from Northern Woodlands magazine. Quote. There's a myth that raccoons
Speaker 1: wash their food, but what they're doing when they wet
Speaker 1: and rubn object is seeing it. It's thought that water
Speaker 1: contact increases a raccoon's tactile ability. When a raccoon wets
Speaker 1: and handles a crayfish, stone worm, or clam, he's gathering information.
Speaker 1: Nearly two thirds of the sensory data that he's processed
Speaker 1: comes from cells that interpret various types of touch sensation.
Speaker 1: In other words, touches as important a sense as hearing, smell,
Speaker 1: and sight. I had no idea. That's fascinating, Yeah, I
Speaker 1: mean it's it's it's I think it's especially hard for
Speaker 1: you know, any of us with with healthy um sight
Speaker 1: to really think about that, to think about that sense
Speaker 1: of touch as being one of the most important ways
Speaker 1: that you interact with your surroundings. Well, there's that, but
Speaker 1: there's also the peripheral sort of mentality that comes along
Speaker 1: with that, right, the the animal personality that is correlated
Speaker 1: with the feeling of touch as an exploratory mechanism, because
Speaker 1: it makes you think that this is a creature that's
Speaker 1: likely to sample objects in its environment at a high rate. Yeah,
Speaker 1: it's it's not enough just to peer at it from
Speaker 1: the shrubs. It's got to get up there. It's got
Speaker 1: to handle it and see what's what. So you know
Speaker 1: what happens when an adaptive creature with marvelous little hands
Speaker 1: like this ventures into the city, Well, it thrives. And
Speaker 1: raccoons have been of interest to science for over a century.
Speaker 1: Because of this, they flourish in human environments. In nineteen seven,
Speaker 1: psychologist Lawrence W. Cole and Clark University graduate student Herbert
Speaker 1: Burnham Davis both independently studied raccoon intelligence in light of this,
Speaker 1: and they concluded that they were smarter than cats and
Speaker 1: dogs and were more in the cognitive realm of monkeys.
Speaker 1: Now not everyone agrees with that. I should note now,
Speaker 1: whatever the baseline level of raccoon intelligence, as far as
Speaker 1: object manipulation and all that goes, there is one thing
Speaker 1: that has become clear, which is that there's a pretty
Speaker 1: large variation in the difference between different populations of raccoons
Speaker 1: and their intelligence at say, uh spatial problem solving, right,
Speaker 1: the distinction being that of city raccoons and country raccoons,
Speaker 1: rural and urban raccoons. Right, it seems like one of
Speaker 1: those populations has more incentive to get smart about how
Speaker 1: to mess with objects. That's right. So Susan mcdonne, old
Speaker 1: comparative psychologist at York University in Toronto. She compared the
Speaker 1: problem solving abilities of urban and rural raccoons and found
Speaker 1: that urban raccoons win in both intelligence and ability. Yeah.
Speaker 1: I was reading about one of these studies, and apparently
Speaker 1: it required the raccoon to figure out how to get
Speaker 1: into a food baited trash can that had its lid
Speaker 1: held shut with a bungee cord. And apparently in the
Speaker 1: study I was reading about, none of the rural raccoons
Speaker 1: could get into the trash can, but about eighty percent
Speaker 1: of the city raccoons did. Yeah. And in a two
Speaker 1: thousand and sixteen Nautilus article titled the Intelligent Life of
Speaker 1: the City Raccoon, Jude Isabella points out the following uh
Speaker 1: in this regarding the study quote. For the past few summers,
Speaker 1: she videotaped rural and urban raccoons toying with containers baited
Speaker 1: with cat food. While both rural and city raccoons readily
Speaker 1: approached familiar containers, they dealt differently with unfamiliar ones. Where
Speaker 1: rural raccoons took a long time to approach novel conta
Speaker 1: aner's city raccoons would attack them the moment she turned
Speaker 1: her back. I like that opportunism, and that's great. Yeah,
Speaker 1: so I got one of the ideas here is city raccoons.
Speaker 1: They're they're fast to get in there, they're fearless and
Speaker 1: approaching a problem. But they also that there they stick
Speaker 1: with the problem that they're trying to figure out. They'll
Speaker 1: work at it for an hour or more, trying to
Speaker 1: figure out how do I get into this, how do
Speaker 1: I how do I defeat this problem? That just shows
Speaker 1: perseverance pays off. Yeah, and then this also brings us
Speaker 1: back just to the idea of a city, like what
Speaker 1: does the artificial environment of a city do well? Isabella
Speaker 1: cites the work of Harvard economist Edward Glacier Uh, the
Speaker 1: author of Triumph of the City uh and Uh. Glacier
Speaker 1: argues that cities themselves are machines for learning uh and
Speaker 1: if raccoons are innately bold and curious uh, then they
Speaker 1: engage with these puzzles more readily. What's more increasingly complex,
Speaker 1: latches and and UH and other devices they may be encountering. Quote,
Speaker 1: may actually be training raccoons to open them. So the
Speaker 1: city itself, as we change it, trains the raccoons and
Speaker 1: sort of changes them. Now, an important thing to consider
Speaker 1: is that this might be happening at multiple levels of
Speaker 1: honing the skills of raccoons. Right, you can imagine on
Speaker 1: in one sense, raccoons are just getting better at solving
Speaker 1: puzzles within their lives, right, they may to some extent
Speaker 1: be learning how to adapt to this. But in another extent,
Speaker 1: they may be getting better at solving puzzles across generations. Right.
Speaker 1: The ones that solve more of these puzzles tend to
Speaker 1: get more food and thus have more offspring. And thus
Speaker 1: it's possible we're literally seeing an evolution of the city
Speaker 1: raccoon into a baseline smarter animal, or at least an
Speaker 1: animal that's better at manipulating these kinds of traps and
Speaker 1: foreign objects. Yeah, in a way, it's like the city
Speaker 1: raccoons are in more of an arms race with their environment,
Speaker 1: whereas the rural raccoons there's their environment is a bit
Speaker 1: more static. Now at the same time, I mean, we've
Speaker 1: already touched on the growing city and uh and one
Speaker 1: of the ramifications of that is that it diminishes the
Speaker 1: the rural environments, and that is very evident when it
Speaker 1: comes to foxes, especially the foxes of Britain. According to
Speaker 1: the two thousand seventeen article and The Guardian, Foxes Surge
Speaker 1: into England's towns and Cities by Charlie cuff Um, the
Speaker 1: overall number of UK foxes is in decline, but the
Speaker 1: number of urban foxes has quadrupled over the past twenty years.
Speaker 1: One study estimates that a hundred and fifty thousand foxes
Speaker 1: thrive in England one for every three hundred city dwellers.
Speaker 1: That's up from thirty three thousand in the nineties. Essentially,
Speaker 1: what's happening here is that the foxes are losing their
Speaker 1: rural habitats and they're just finding a lot more food,
Speaker 1: including garden worms and all those rats and mice, as
Speaker 1: well as suitable habitats in the urban environment. Skill tous
Speaker 1: And talks about this in his book, mentioning that some
Speaker 1: of what drives animals into the city is not just
Speaker 1: what's available in the city or the fact that the
Speaker 1: city now exists where their home used to be. But
Speaker 1: the depletion of the habitability of the surrounding landscape. This
Speaker 1: is happening all over the place. Even though cities are
Speaker 1: these extremely weird, alien places for animals to try to
Speaker 1: survive in, they tend to be more habitable environments than
Speaker 1: the waste lands created just outside of cities. I'm reminded
Speaker 1: of the witches gingerbread house in the woods. You know,
Speaker 1: for a couple of kids who are lost in the woods,
Speaker 1: there's no more dangerous place than going into that gingerbread house.
Speaker 1: But at the same time, the woods are terrifying and
Speaker 1: full of inedible things and berries that will poison you
Speaker 1: if you try and eat them, whereas the witches houses
Speaker 1: made out of candy. How can you work out a
Speaker 1: deal with this witch? That's the challenge. But what if
Speaker 1: the candy is just all of the trash that the
Speaker 1: wit threw away because she didn't want to eat herself. Well,
Speaker 1: so we are on the subject of trash life. Of course,
Speaker 1: much of what we're talking about with the raccoons is
Speaker 1: how they are affected by by urban trash and what's
Speaker 1: trash to us maybe delicious morsels for many scavenging animals,
Speaker 1: especially if they're not super picky, and they're smart at
Speaker 1: manipulating containers and things like that. But I thought we
Speaker 1: should explore some of the more of the ways that
Speaker 1: the pervasive presence and endless forms of human garbage, and
Speaker 1: I mean the garbage produced by humans, not people who
Speaker 1: are garbage, how that shaped urban animal life. So I've
Speaker 1: got one, Robert, Do you remember the mcflury hedgehog? I
Speaker 1: do not remember the mcflury hedgehog. Have you ever had
Speaker 1: mcflury in in the past. I believe I did have
Speaker 1: the mcflury or two. Yes, I'm not trying to be
Speaker 1: a snob. I can say I've never had one of
Speaker 1: these things, so I can't speak from experience, but maybe
Speaker 1: you can help guide me on the mcflury ology. Here.
Speaker 1: The only thing I remember is that they had a
Speaker 1: weird top. Yeah, that's that's the thing. So back in
Speaker 1: the mid nineties, McDonald's fast food restaurant introduced the mcflury,
Speaker 1: which is it's some kind of ice cream thing, right,
Speaker 1: God knows what it's like, hamburger flavored ice cream. So
Speaker 1: now you're now you're just trash talking to mcflury. It
Speaker 1: was at least it was sweet. It was sweet flavor
Speaker 1: does have big MAC sauce in it, No, but it's
Speaker 1: it's all I remember, is just an overpowering sweetness. Well,
Speaker 1: so this sweet stuff that was in the mcflurry, it
Speaker 1: was served out of containers with these weird lids you're
Speaker 1: talking about that essentially functioned as a hedgehog trap. So
Speaker 1: the way it seemed to work is that you'd be
Speaker 1: eating your mcflurry and then you'd throw the container down
Speaker 1: on the sidewalk or the parking lot, and then later
Speaker 1: a hedgehog would come along and want some of that
Speaker 1: delicious reeking sugar stuff inside the cup. But the aperture
Speaker 1: in the lid, which would I guess made for spoon access,
Speaker 1: so you could use a spoon. It was just big
Speaker 1: enough for hedgehogs and some skunks to stick their heads
Speaker 1: inside and slurp up some mcmlty. But then, of course
Speaker 1: hedgehogs have bines, and the spines are generally oriented to
Speaker 1: fold backward from the head, so once the hedgehog's head
Speaker 1: is in the hole, it might not be able to
Speaker 1: get itself back out of the mcflurry cup. So, on
Speaker 1: the one hand, this is funny. I've included an image
Speaker 1: for you to look at. It is funny and very
Speaker 1: cute and lead too much laughter about little creatures running
Speaker 1: around with their heads stuck in cups. But there's a
Speaker 1: dark side, right, which is that if nobody helped these
Speaker 1: creatures out, nobody saw them, they would probably die right
Speaker 1: possibly of starvation, or they might wander into traffic, or
Speaker 1: they might wander into a body of water and drown.
Speaker 1: Oh yeah, that is terrifying. It At first it's cute,
Speaker 1: and then when it it's explained to you, then then
Speaker 1: it is a very sad affair. But fortunately there was
Speaker 1: a good end to it. After years of complaints from
Speaker 1: organizations like the British Hedgehog Preservation Society in two thousand six,
Speaker 1: McDonald's eventually changed the design of their lids to make
Speaker 1: them too small for hedgehogs to get their heads through
Speaker 1: in the first place. So fortunately that had a good resolution.
Speaker 1: But that's just one exam ample of the thousands of
Speaker 1: ways we can't even predict about how the shape or
Speaker 1: chemistry or nutritional profile or whatever of human refuse will
Speaker 1: exploit some fatal flaw in another organism. And also you
Speaker 1: always have to wonder how if McDonald's had never intervened.
Speaker 1: This might have shaped the evolution of city dwelling hedgehogs, right,
Speaker 1: would this cause a selection pressure for hedgehogs that were
Speaker 1: better at getting their heads out of small holes, or
Speaker 1: for hedgehogs with big heads that would never get through
Speaker 1: the hole to begin with, or for hedgehogs that didn't
Speaker 1: like the smell of dairy products and wouldn't be interested
Speaker 1: in ice cream. So let's dig through more trash, Robert,
Speaker 1: you're ready to dig through more to do it? What
Speaker 1: else is in there that's that's worth eaten? How about
Speaker 1: beatles and bottles? Have you ever read this story before, Robert,
Speaker 1: I've read Fox in Socks where there's a much discussion
Speaker 1: of of beatle battles inside of a bottle. No, no, no,
Speaker 1: this is beatle. This is not a battle. This is
Speaker 1: a beatle something else outside of a bottle. So I
Speaker 1: want to take you to Australia to meet the Julo
Speaker 1: Dimorpha bake Welly, which is the Australian jewel beetle. It's
Speaker 1: a type of beetle from the boot breasted family found
Speaker 1: throughout a lot of parts of Australia, and so in
Speaker 1: nineteen eighty three, there were a couple of biologists named
Speaker 1: Darryl Quinn and David Rince, and they published some interesting
Speaker 1: findings about human trash and its local effects on wildlife
Speaker 1: in the Journal of austral Entomology. So here's the story.
Speaker 1: Earlier that year, in nineteen eighty three, the authors were
Speaker 1: wandering out beside a highway near a town called Donra
Speaker 1: in Western Australia, and they noticed something weird. A male
Speaker 1: jewel beetle perched on top of a piece of litter,
Speaker 1: which was a discarded brown beer bottle. Okay, well, that
Speaker 1: in and in and of itself is not that strange. Uh.
Speaker 1: Then they got closer and they looked see what's going
Speaker 1: on here, and they realized the beetle was trying to
Speaker 1: mate with the beer bottle. The authors looked around and
Speaker 1: they found two more beer bottles of the same type,
Speaker 1: both of which had male bake wellies trying to mate
Speaker 1: with them, and the males were either on the side
Speaker 1: of the bottle or quote mounted on top with quote
Speaker 1: averted genitalia. And I've got a picture here of what
Speaker 1: the beetles look like with averted genitalia. Okay, I'm seeing
Speaker 1: it now. I don't know if you have any comments
Speaker 1: on that, um I do. It does convey the sense
Speaker 1: that this, uh, this insect is trying to mate with
Speaker 1: the bottle. That's quite averted, So what's going on here? Well,
Speaker 1: The authors noted that bake Welly is a species in
Speaker 1: which males can fly and the females are ground dwelling,
Speaker 1: and the color and texture of these beer bottles in
Speaker 1: many ways resembled a giant female of this beetle species.
Speaker 1: The author's right quote the shiny brown color of the
Speaker 1: glass is similar to the shiny yellow brown electra of J.
Speaker 1: Bake Welly and quote rows of regularly spaced small tubercles
Speaker 1: around the base of the bottles reflect light in a
Speaker 1: similar way to the punctations on the electra of the beetle.
Speaker 1: So the brown beer bottles referred to as stubbies in
Speaker 1: Australia at the time. We're proving very efficient at setting
Speaker 1: off mating behaviors in male beetles, and almost alarmingly so,
Speaker 1: because when the author's picked up the bottles, the beatles
Speaker 1: would not leave them unless physically removed. And then the
Speaker 1: authors also performed an informal experiment where they placed four
Speaker 1: stubbies these beer bottles on the ground and watched to
Speaker 1: see what happened, and within thirty minutes, two of the
Speaker 1: four bottles had male beetles trying to mate with them.
Speaker 1: And it gets worse. I want to read a quote
Speaker 1: from their paper. Quote. In one of the observations, a
Speaker 1: male at the side of the bottle was being attacked
Speaker 1: by a number of ants which were biting at the
Speaker 1: soft portions of his averted genitalia. A dead male covered
Speaker 1: in ants was located a few centimeters away from this
Speaker 1: same bottle. So these things are literally dying to mate
Speaker 1: with glass bottles because just going off of their genetic
Speaker 1: programming like this is their purpose. I have come here
Speaker 1: to mate with this. This is glorious and large of females,
Speaker 1: and I must do so even as answer tearing me
Speaker 1: apart exactly right, ants maybe chewing off my genitals, But
Speaker 1: it is worth it because this bottle sets off all
Speaker 1: of my internal signals for amazing attractiveness in a female
Speaker 1: of my species. So there is another fortunate ending from
Speaker 1: the human perspective. I reade a report on NPR that
Speaker 1: the bottle designers became aware of this and eventually they
Speaker 1: changed the bottle design to remove the small bumps on
Speaker 1: the glass. After they did that, the male beetles stopped
Speaker 1: caring about them. Oh that's good. But once again, you
Speaker 1: can imagine what would have happened if nobody noticed this
Speaker 1: and the bottle makers never changed their methods. Will never know,
Speaker 1: but one possibility is these beetles could have become endangered
Speaker 1: or gone extinct, with all the healthy males refusing to
Speaker 1: mate with actual females because they preferred glass bottles. These
Speaker 1: bottles were better looking than the real members of the species.
Speaker 1: But in other possibilities, the species would have evolved to
Speaker 1: favor different sexual preference genes and males. Right that males
Speaker 1: would be not attracted to whatever features set off the
Speaker 1: extreme bottle desire, but to something else, maybe sent or
Speaker 1: something like that. And I mean again, just the crazy
Speaker 1: thing about this is that it's not like they were
Speaker 1: setting around trying to come up with a bottle design
Speaker 1: that would throw off beetle mating in the immediate area.
Speaker 1: This was just pure accident, but it could have had
Speaker 1: disastrous consequences for the species. All this stuff is pure accident.
Speaker 1: Now I want to explore an accident that went a
Speaker 1: different way where animals have been found to be adapting
Speaker 1: in a positive way to harmful trash being thrown into
Speaker 1: their environment. Uh. Do you ever have that friend Robert
Speaker 1: who thought it was cool to flick cigarette butts out
Speaker 1: into the world when they're done smoking. You know, they're
Speaker 1: like the system man, they finished there and just flicked
Speaker 1: the butt. I have not, but I will still occasionally
Speaker 1: see somebody at like a stoplight that's doing that, and
Speaker 1: I judged them rather harshly. Yeah, it's not cool to do.
Speaker 1: Don't don't litter the world with your cigarette butts. But
Speaker 1: it actually that was not a pun, by the way. Uh,
Speaker 1: there's an interest follow up to this. So. Montserrat Suarez
Speaker 1: Rodriguez is an ecologist at the National Autonomous University of
Speaker 1: Mexico in Mexico City, and she and her colleagues Isabel
Speaker 1: Lopez Rule and Constantino Marcius Garcia published some fascinating research
Speaker 1: in Biology Letters in and they started by pointing out
Speaker 1: something really interesting about the birds of Mexico City. The
Speaker 1: birds were putting discarded cigarette butts in their nests. Okay,
Speaker 1: well that that in and on itself doesn't sound crazy,
Speaker 1: because if they're if there are a lot of these around.
Speaker 1: If cigarette butts are more forthcoming than twigs, then why
Speaker 1: not put them in your nest? Right? Yeah, they're fiber, right,
Speaker 1: So if the cities are full of littered cigarette butts,
Speaker 1: maybe the urban birds will just use whatever kind of
Speaker 1: fiber is around to be part of the nest that.
Speaker 1: You know, there's some cellulose here, I'll put it in
Speaker 1: the structure of the nest. But these researchers performed experiments
Speaker 1: and they found something pretty amazing. They looked at the
Speaker 1: nests of house sparrows, which are passer domestica us and
Speaker 1: house finches, which are Carpodacus and mexicanus, and they found
Speaker 1: that the more cigarette butts a nest contained, the fewer
Speaker 1: parasitic mites could be found in the nest. Now why
Speaker 1: would that be, Well, cigarette butts contain a cellulose filter
Speaker 1: through which the smoke passes when you smoke a cigarette, right,
Speaker 1: and this filter traps all kinds of compounds from the smoke,
Speaker 1: including nicotine, the stimulant drug in the tobacco products. So
Speaker 1: why do tobacco plants contain nicotine in the first place.
Speaker 1: It's because it is a poison designed to deter herbivorous
Speaker 1: animals from eating the plants, including insects, and it's even
Speaker 1: been used by humans directly as an insecticide. Oh, so
Speaker 1: this is a for the birds and naturally occurring insecticide
Speaker 1: in their artificial city environment. Exactly, the birds have parasitic
Speaker 1: arthropods that attack them in their nests, but if they
Speaker 1: line their nests with insecticide traps found among the trap
Speaker 1: shin gutters of the city, they can repel these parasites.
Speaker 1: And the researchers confirmed this by setting up traps to
Speaker 1: attract parasites lined with two types of cigarette butts. They
Speaker 1: had smoked butts and unsmoked butts, and the parasites were
Speaker 1: much more deterred from the nest that had the smoked
Speaker 1: butts in them. Now, why would that be. The smoked
Speaker 1: butts contained the nicotine because the smoke had come through them,
Speaker 1: while the unsmoked butts didn't contain any they were just
Speaker 1: the cellulose. So the researchers determined it was not just
Speaker 1: the fiber, really was the nicotine. And now, at the
Speaker 1: same time, that's an ingenious adaptation to the available materials
Speaker 1: of a city. But we also shouldn't conclude that this
Speaker 1: is always going to be good for the birds, because exposure,
Speaker 1: of course, could have negative side effects that haven't been
Speaker 1: identified yet. We all know what some of the negative
Speaker 1: side effects of exposure to tobacco products can be. But
Speaker 1: still they've they've essentially made a protective chemical weapon out
Speaker 1: of these discarded cigarette butts. Now here's another thing about
Speaker 1: the physical environment of cities that most of us probably
Speaker 1: wouldn't even stop to think about. But there is an
Speaker 1: extremely simple diff friends in the kinds of physical surfaces
Speaker 1: one encounters more often in the city versus the country. Right,
Speaker 1: what kind of animal is actually evolved to live on hard, flat,
Speaker 1: relatively smooth surfaces with no vegetation cover that you can't
Speaker 1: dig down into? And that sounds like a nightmare? Right, Yeah? Like,
Speaker 1: what kind of creatures do would you typically find scurrying
Speaker 1: about on rocks and other flat surfaces? I mean not
Speaker 1: that many. I mean you some live on rocks, but
Speaker 1: at least then you'd have vegetation nearby, or you could
Speaker 1: retreat down into cracks between the rocks. The sort of flat,
Speaker 1: unbreakable surfaces of the city are, and especially the smooth
Speaker 1: ones are just not great for many animals, but nevertheless,
Speaker 1: animals adapt, life finds a way. So another study I
Speaker 1: want to mention is that a team led by Kristen
Speaker 1: Winchell of the University of Massachusetts, Boston examined males of
Speaker 1: the animal lizard which is Enolis christ to tell Us
Speaker 1: from a couple of cities in Puerto Rico and compared
Speaker 1: them to males of the same species from adjacent four
Speaker 1: wrists And was there any biological difference? You bet. They
Speaker 1: actually published their results in the journal Evolution in sixteen,
Speaker 1: and what they reported was that the city lizards had
Speaker 1: both longer legs and they had more lamela, which are
Speaker 1: these structures on the toes on the undersides of the
Speaker 1: feet that helped the toes stick to surfaces, especially smooth surfaces.
Speaker 1: So these traits were probably helping the lizards, helping these
Speaker 1: animal lizards evolved to be able to climb smooth walls
Speaker 1: and stay attached to these smooth, slippery surfaces, even vertically
Speaker 1: aligned ones. Yeah, these these kind of like essentially like
Speaker 1: hyper surfaces. Is that you're not going to find something
Speaker 1: that is that is that flat, uh and in featureless
Speaker 1: that that vertical in the natural environment. Yeah, and so
Speaker 1: to test whether this was an actual inherited trait, they
Speaker 1: also raised lizards from stock captured in the city and
Speaker 1: from stock captured in the forest, and they raised them
Speaker 1: both in the lab just to make sure it was
Speaker 1: a true genetic difference and not some weird way the
Speaker 1: lizards were able to change their bodies during life, and
Speaker 1: it turned out it was a true heritable difference. The
Speaker 1: city lizards hatched wall climbers with these more lamlay and
Speaker 1: the longer legs, and the forest lizards did not. And
Speaker 1: you can imagine that so many city species are evolving
Speaker 1: along these lines with small changes in their body just
Speaker 1: to get a better grip on the surfaces of human
Speaker 1: made environments. Right, Yeah, it makes perfect sense. Like this
Speaker 1: is the this is the geography you're presented with. Now,
Speaker 1: while we're on the subject of crawling reptiles, I want
Speaker 1: to know something about city dwelling animals. Is it true
Speaker 1: that there are colonies of alligators living in the New
Speaker 1: York sewers? Ah, Now, this is a fun, fun topic.
Speaker 1: Sometimes they are they're they're reported to be blind like
Speaker 1: albino alligators living Yeah, in like thick packs in the
Speaker 1: depths of say the New York sewer system. Is this
Speaker 1: ever addressed in one of the Blade movies. I don't
Speaker 1: think so. Maybe unless they made passing reference to it.
Speaker 1: I'd know it shows up in Teenage Mutant Ninja Turtles,
Speaker 1: So it would have been a great set piece to have,
Speaker 1: like Blade Battle, like an albino crocodile vampire that lives
Speaker 1: in the sewers. Well, we have at least one film.
Speaker 1: There's a nineteen eighties alligator. Do you remember this one?
Speaker 1: I've never seen it. I should have. I don't know
Speaker 1: why I haven't seen it. Oh man, I saw it
Speaker 1: as a kid. It was It was a lot of fun.
Speaker 1: It started Robert Forster, and it takes place in Chicago,
Speaker 1: though not in New York City, which is a shame
Speaker 1: considering what I'm about to lay on everybody, Well, tell me,
Speaker 1: is it real? Okay? It? Well, it's not real. I
Speaker 1: think if you were near a New York sewer right now,
Speaker 1: do not worry about the blind alligators climbing up after you.
Speaker 1: I looked at a nineteen seventy nine paper, Alligators in
Speaker 1: the Sewers, A journalistic origin by Lauren Coleman, published in
Speaker 1: the Journal of American folklore, and um, she this is interesting.
Speaker 1: She points to Thomas Pension, uh, the famed American author
Speaker 1: of Gravity's Rainbow, as someone who did not He did
Speaker 1: not originate the tale, but he helped to propagate it,
Speaker 1: and propel it through his debut nine novel V in
Speaker 1: which there's this, uh, this this brief discussion of you know,
Speaker 1: the classic trope baby alligators that are acquired at a
Speaker 1: carnivore fair or on a trip to Florida. You come
Speaker 1: back to New York, they start getting bigger. So what happens?
Speaker 1: They get flushed down the toilet or thrown out and
Speaker 1: then they wind up in the sewer. That sounds like
Speaker 1: a cruel thing to do to a baby alligator, I agree,
Speaker 1: But it it's this, you know, this idea that, oh, well,
Speaker 1: they wind up here by accident, and then they wind
Speaker 1: up down there, and then they thrive quote down there.
Speaker 1: God knew how many there were. Some had turned cannibal
Speaker 1: because in their neighborhood the rats had all been eaten
Speaker 1: or had fled in terror, thanks Thomas Pension. But Coleman
Speaker 1: digs deeper than than this. So various authors and even
Speaker 1: herpetologist she found, referred to the urban legend, but they
Speaker 1: cited it as such. They were not saying this is true.
Speaker 1: They were saying, hey, this is crazy story some people
Speaker 1: tell um claiming, you know, they grow fat on New
Speaker 1: York sewer rats, they and or they grow pale and
Speaker 1: blind in the depths. But then she explored more than
Speaker 1: seventy reports of just alligator sightings in general in Northern
Speaker 1: American climates, such as an eight account of a frozen
Speaker 1: gator that's supposedly watched up on the banks of the
Speaker 1: Rock River in Wisconsin. But she found just one single
Speaker 1: account of a sewer gator that was at the time
Speaker 1: actually reported as fact. And she admits that this may
Speaker 1: have never taken place. It could be, you know, a
Speaker 1: fraudulent story, but the matter of fact reporting style and
Speaker 1: the fact that this was a very established paper may
Speaker 1: have caused the story to simply explode. Wait what paper
Speaker 1: was it? The New York Times, February five. You can
Speaker 1: find this full um this full article online either uh
Speaker 1: in the New York Times are archives which I believe
Speaker 1: you need a membership to access. But then other people
Speaker 1: have have have reproduced it elsewhere on the web. This
Speaker 1: is the title alligator found an uptown sewer youth shoveling
Speaker 1: snow and man hoole see the animal churning and the
Speaker 1: icy waters snare it and drag it out reptile, slain
Speaker 1: by rescuers when it gets vicious. Whence it came is mystery,
Speaker 1: So I'm gonna let everyone else go read this on
Speaker 1: their own. I'll include a link to it on the
Speaker 1: landing page for this episode of Stuff Toblow your Mind
Speaker 1: dot Com. But essentially the idea is, uh, the they
Speaker 1: discover this sewer gator and they're frightened by it, and
Speaker 1: then they drag it up and onto the onto the snow,
Speaker 1: and then beat it to death with snow shovels. Yea, why,
Speaker 1: it's just what you do, I guess when you're frightened
Speaker 1: of a of a large creature. But then it But again,
Speaker 1: I want to stress this doesn't mean this actually happened. Yes,
Speaker 1: it made it into the New York Times, but when
Speaker 1: you start looking at the evidence that you still have
Speaker 1: to doubt that this really occurred. Okay, Well, what about
Speaker 1: sewer gators in general? I mean, is there any evidence
Speaker 1: that there might be gators living in the sewers underneath
Speaker 1: some cities? Well, I looked into this a little bit.
Speaker 1: So for one question that immediately came to mind is, Okay,
Speaker 1: New York is u is a bit too far north
Speaker 1: for alligators to really have a chance. But are alligators
Speaker 1: living in sewers in say Florida? And uh and yeah,
Speaker 1: you you do see reports of gators winding up in
Speaker 1: Florida storm drains or sewers and many of and this
Speaker 1: is because many of these waste outlets back out into
Speaker 1: the swamps. But New York sewers not really outside of
Speaker 1: just pure you know, urban legend. This one story and
Speaker 1: also an account from two thousand ten in which a
Speaker 1: baby gator was found in a Chinatown sewer, there's not
Speaker 1: a lot to go on. And with that baby gator,
Speaker 1: it's I'm it seems like it was probably just a
Speaker 1: case of somebody through this this creature out into the
Speaker 1: sewer and then it was found. This is not the
Speaker 1: same as say, adult sewer born alligators popping up in
Speaker 1: Times Square. And then I should also mentioned that snopes
Speaker 1: dot com has an article on this, and they point
Speaker 1: to the writings of nature writer Diane Ackerman. She points
Speaker 1: out that the gators would only be able to survive
Speaker 1: for a few months at the most. In New York sewers,
Speaker 1: I would guess this would probably be the summer months, right, right,
Speaker 1: because the big thing is the temperature. They're gonna need
Speaker 1: temperatures between eighty seven and ninety degrees fahrenheit. And we're
Speaker 1: talking about them living in the sewer. Uh, They're they're
Speaker 1: gonna be surrounded by Salmonella E coli, shigela, other sewer
Speaker 1: microbes that they're just not going to be able to
Speaker 1: live with those. They're going to die in there. A
Speaker 1: sewer is just not a suitable habitat for an alligator. Yeah,
Speaker 1: And I think this does draw attention to the fact
Speaker 1: that while we do see many animals uh coming up
Speaker 1: with fascinating adaptations and even evolving to be better fits
Speaker 1: for city life, not all animals are good candidates for this,
Speaker 1: and certainly not all animals are good candidates for this
Speaker 1: in all cities. Yeah, because with the alligator, for instance,
Speaker 1: in in Florida, Yes, during the colder months, a storm
Speaker 1: drain environment can be actually an excellent place for a
Speaker 1: gator to hold up. All right, on that note, we're
Speaker 1: going to take another quick break and then we'll be
Speaker 1: right back all right, We're back all right. Now we've
Speaker 1: been talking about the myth of the New York sewer gators,
Speaker 1: which does not turn out to be true, and this
Speaker 1: has highlighted some of the ways in which not all
Speaker 1: animals are well suited to all city environments. Some are
Speaker 1: much more suited to it than others. One animal that
Speaker 1: has proven extremely well suited to city environments that is
Speaker 1: a larger predator, kind of like an alligator, but very
Speaker 1: different type, is the coyote. Yeah. And I've always found
Speaker 1: this interesting because when I've lived in very rural environments
Speaker 1: and when I've i've lived in urban environments, they're all
Speaker 1: essentially all I encounter are mostly tales of the coyote.
Speaker 1: It's such a secretive and stealthy animal that it's more
Speaker 1: of a It's it's almost supernatural, this this beast that
Speaker 1: is there, but you're only aware of it through its
Speaker 1: childlike noises from the kud zoo under dark, just you know,
Speaker 1: reaching out after you. Yeah, I mean, it's it's haunting.
Speaker 1: That's this beautiful image. I don't usually think of coyotes
Speaker 1: that way. I guess they're so common in cities. Now
Speaker 1: we've started they've started to lose some of their wildlife magic,
Speaker 1: and we start to think of them as like, oh,
Speaker 1: that's like a city rat or something, you know. But no,
Speaker 1: it's a It's a coyote. This is a large, candid predator.
Speaker 1: I mean, this is an interesting thing, the fact that
Speaker 1: they're colonizing our cities so much so. I found an
Speaker 1: interesting Ohio State University news report on the work of
Speaker 1: the os U wildlife ecologist stand Girt, who has been
Speaker 1: studying urban coyotes, and some interesting facts and observations from
Speaker 1: Girt's research. One is that coyotes have colonized pretty much
Speaker 1: every big city in the United States. In somebody even
Speaker 1: snapped a picture of a coyote standing on the roof
Speaker 1: of a bar in Queens. Wow, how did it get there?
Speaker 1: I don't know they I think they think maybe it
Speaker 1: got out from a window of a building nearby or
Speaker 1: something like that. In Queens, there's a coyote on the
Speaker 1: roof of a bar. And this actually just isn't all
Speaker 1: that weird as weird as it seems, because coyotes are
Speaker 1: everywhere in our cities. Gert has observed coyotes adapting to
Speaker 1: city traffic, literally pausing at the edge of the street,
Speaker 1: looking at the direction that traffic comes from, and checking
Speaker 1: for oncoming traffic. Because in an urban environment we've already
Speaker 1: talked about the idea of cars as predators. The number
Speaker 1: one cause for death for a coyote in a city
Speaker 1: is getting hit by a car. But those risks are
Speaker 1: paired with big rewards because Girt's research has found that
Speaker 1: an average litter size for an urban coyote is nine pups,
Speaker 1: which is bigger than the average litter size in rural areas.
Speaker 1: And this means city coyotes are fattening up on abundant resources.
Speaker 1: And this is possible because coyotes can make you of
Speaker 1: all kinds of resources their omnivores. They'll lead almost anything,
Speaker 1: and these are the kinds of organisms that tend to
Speaker 1: do well in cities. Now, on the other hand, people
Speaker 1: have started to see them very much as an urban nuisance.
Speaker 1: I even found a New York Times article about the
Speaker 1: trend of urban hunters culling city coyote populations. Have you
Speaker 1: read about I have not heard about this. I've heard about,
Speaker 1: you know, rat hunters, obviously, but this is the first
Speaker 1: effort about the coyote hunters. Yeah, so because of this
Speaker 1: kind of action and the fact that we will never
Speaker 1: seem to get rid of all of them, I wonder
Speaker 1: if we may actually be driving a selection regime to
Speaker 1: evolve urban coyotes that are guess what, good at hiding
Speaker 1: from humans. And there's a cool example of this that's
Speaker 1: actually already been reported in places like National Geographic so uh,
Speaker 1: to quote from that GEO article on it, quote in
Speaker 1: downtown Chicago, one GPS collared coyote pair raised a litter
Speaker 1: of five healthy pups inside a secret concrete den in
Speaker 1: the parking lot of Soldier Field Stadium, home of the
Speaker 1: Chicago bears a high traffic environment, but the signals to
Speaker 1: me the emergence of of invisibility traits in these creatures.
Speaker 1: You know, they find those places where no one will
Speaker 1: look for them. Okay, one last animal to look at.
Speaker 1: There are millions of ways we could look at mice,
Speaker 1: but there is one way that I think is going
Speaker 1: to be particularly interesting. So one of the ways we
Speaker 1: don't often think about the effects of the techno ecosystem
Speaker 1: of the city is that it creates urban islands. And
Speaker 1: this could be counterintuitive to us, because to us, a
Speaker 1: city is actually one of the easiest places in the
Speaker 1: world to get around. Right, there's no rocky terrain, there's
Speaker 1: no forest blocking the way of getting through things. A
Speaker 1: city is the place where you can go to somewhere, right, Yeah,
Speaker 1: I mean you hear about Oh, this is a very
Speaker 1: walkable city. You can just get out and walk wherever
Speaker 1: you want. You don't have to cross a river, scale
Speaker 1: a mountain. It's just all there. But for many animals,
Speaker 1: a city is exactly the opposite. So his book Skill
Speaker 1: Tousand points out many ways that cities start to recreate
Speaker 1: the principles of island biogeography by allowing small patches of
Speaker 1: habitable environment that are separated from one another by all
Speaker 1: kinds of virtually impassable barriers, freeways or even small roads.
Speaker 1: For some animals, breaks and vegetation cover. There are all
Speaker 1: kinds of barriers we wouldn't even think of. So Skill
Speaker 1: Tousand mentions a case of something kind of like island
Speaker 1: evolution from within New York City, specifically the work of
Speaker 1: a zoologist named Jason Munshi south of for Fordham University,
Speaker 1: who studies the way that different isolated populations of mice
Speaker 1: have evolved for specializations for different parks of New York
Speaker 1: City now Munchie South. Research is focused on the white
Speaker 1: footed mouse or Paramiscus leucopus, and this mouse inhabited the meadows, swamps,
Speaker 1: and forests to the New York City area long before
Speaker 1: humans ever settled there, so it's not the kind of
Speaker 1: mouse that follows human settlements everywhere. It's a local has
Speaker 1: clung onto survival in the city that rose up around it,
Speaker 1: and so originally this population of white footed mice would
Speaker 1: have been a single combined population with continuous interbreeding throughout.
Speaker 1: But the populations that have survived up until now in
Speaker 1: New York are isolated from one another on the islands
Speaker 1: of New York's parks. So there's a population in Central
Speaker 1: Park and one in Prospect Park, and more in smaller
Speaker 1: parks around the city. And the mice can do pretty
Speaker 1: well in these parks because most of the park's actually
Speaker 1: aren't big enough to support natural predators like owls or foxes.
Speaker 1: But the different park populations don't tend to interbreed with
Speaker 1: one another very much, which means they're free to evolve
Speaker 1: independently in different directions, whether through local natural selection or
Speaker 1: just through genetic drift. Yeah, because how's a mouse going
Speaker 1: to get from say, Washington Square Park all the way
Speaker 1: to Central Park. Are they're gonna They're gonna take the train. Now,
Speaker 1: I mean some some rodents will be better at traversing
Speaker 1: the city in that way than others. These mice are
Speaker 1: very shy. They want vegetation cover. They don't want to
Speaker 1: come out from under the plants they live beneath. So
Speaker 1: unless there was like a land bridge of parks between
Speaker 1: the two, right, yeah, they're probably not going to leave
Speaker 1: their island. Now. It's not that mixing never happens, but
Speaker 1: it's very rare, and rare enough that these populations do
Speaker 1: have evolved to become genetically distinct. Munchie South and colleagues have.
Speaker 1: They've been tracking the evolution of these different park populations
Speaker 1: by trapping mice from each of the parks and performing
Speaker 1: cross reference to DNA tests. Now, gene pool fragmentation like
Speaker 1: this is generally considered bad for the health of a
Speaker 1: species in a long run. This is one of the
Speaker 1: reasons you see these wildlife corridors, you know, that are
Speaker 1: so important. It's because they help creatures from one side
Speaker 1: of a freeway come to the other side so they
Speaker 1: can mate and increase the gene flow across the two populations.
Speaker 1: But nevertheless, the fragmented populations of white footed mice seem
Speaker 1: to be doing pretty well, and they've adapted more and
Speaker 1: more to their local conditions in the parks where they live. Now,
Speaker 1: you might think, how could the adaptation pressures of one
Speaker 1: city park be all that different from the pressures of
Speaker 1: another park or another place. I mean, there's some interesting results.
Speaker 1: So here here are some adaptations they found that were
Speaker 1: specific to Central Park mice. The Central Park mice had
Speaker 1: a variation in the a k R seven gene, which
Speaker 1: is involved in neutralizing a flat toxin, which is a
Speaker 1: toxic compound produced by some molds, as Skill tells and
Speaker 1: points out molds that grow on seeds and nuts. Interesting.
Speaker 1: So the obvious implication is that the Central Park mice
Speaker 1: are more exposed to this kind of toxin, probably in
Speaker 1: the foods that they eat. Another one involved in diet
Speaker 1: a variation on the f A d S one gene,
Speaker 1: which is involved in the metabolism of high fat diets.
Speaker 1: This is probably a trash situation, yeah, kind of not
Speaker 1: not hard to see what's going on there. But then
Speaker 1: there are other mutations found in the city park mice
Speaker 1: having to do with diet, metabolism, exposure to pollutants, and
Speaker 1: importantly immune function because, as Munchie South says, quote, very
Speaker 1: easy to spread disease when you're in a small population. Interesting.
Speaker 1: I love this they are since they're evolving to live
Speaker 1: on a diet of one dollar pizza slices. Right, Yes,
Speaker 1: as are many New Yorkers, And so, I mean fair
Speaker 1: is fair, But New Yorkers at least you know, they've
Speaker 1: got more ways to get around, right. These mice live
Speaker 1: on an island, even in the middle of a city.
Speaker 1: It is an island to them. They really can't leave,
Speaker 1: so they deal with what imports arrive. That this is
Speaker 1: going to be going to think about the next time
Speaker 1: you're walking through a city park. Yeah, I mean, it's
Speaker 1: kind of crazy to imagine that the types of trash
Speaker 1: usually littered in one park versus the types of trash
Speaker 1: usually littered in another park. If they're different enough types
Speaker 1: of trash, this could literally be shaping the evolution of
Speaker 1: the creatures that live in those parks. Oh wow, so
Speaker 1: is the human population like that? The details of a
Speaker 1: human population change around a certain park, it could have
Speaker 1: a drafting even disastrous effect on the mice that reside there. Yes,
Speaker 1: food trends come and go a nearby restaurants and stuff
Speaker 1: like that. It's crazy. Yeah, they depend on the avocado
Speaker 1: toast and then what happens when that goes away? Right?
Speaker 1: Oh yeah, we we we went all in on evolving
Speaker 1: to be avocado toast eaters and now you're into what
Speaker 1: grapefruit rice? And I don't want that. Well, I think
Speaker 1: we should wrap up today's episode with just one final
Speaker 1: look at some general trends in urban evolution that have
Speaker 1: been observed across many studies and and of course be
Speaker 1: reminded that we're going to come back and explore more
Speaker 1: examples of urban evolution and adaptation in the next episode here.
Speaker 1: But to sum up today, uh, actually, Jason Munchie South,
Speaker 1: who were we were just talking about, is one of
Speaker 1: the authors of a paper we're about to look at.
Speaker 1: The other author was Mark T. J. Johnson, and this
Speaker 1: was a paper called Evolution of Life in Urban Environments
Speaker 1: published in Science in and this is a huge review
Speaker 1: of research on urban evolution, observed general trends and what's
Speaker 1: been discovered in the literature so far. To discuss one example, uh,
Speaker 1: the general trend they've identified as quote, cities elevate the
Speaker 1: strength of random genetic drift meaning stochastic or random changes
Speaker 1: in alleal frequencies, and restrict gene flow meaning the movement
Speaker 1: of alleles between populations due to dispersal and mating. And
Speaker 1: so this leads to a loss in genetic diversity within
Speaker 1: populations and increasing difference between populations, just like we were
Speaker 1: talking about with the mice, right. Smaller number of studies
Speaker 1: they found indicate that urban pollution can increase mutation rates
Speaker 1: in urban dwelling animals, which might actually speed up evolution, right,
Speaker 1: if you've got more mutations going on. But then also
Speaker 1: when it comes to natural selection, cities tend to present
Speaker 1: different selection pressures the natural environments, and so they say, quote,
Speaker 1: adaptations typically evolve in response to pesticide use, pollution, local climate,
Speaker 1: or the physic coal structure of cities. And that's not
Speaker 1: even counting um canisers of mutagen that are thrown into
Speaker 1: the sewer affect the local turtle population. I mean, you
Speaker 1: can't even factor that in. That's just anomally. But one
Speaker 1: more trade I think would be worth mentioning is something
Speaker 1: that Skill to House and mentions in his book as
Speaker 1: adaptive to many species in cities, and it's what would
Speaker 1: be known as neophilia, or an attraction to strange or
Speaker 1: familiar or unfamiliar objects. Like if you're an animal, neophilia
Speaker 1: obviously cuts both ways. It's a gamble. If you approach
Speaker 1: a strange, unfamiliar object, it could turn out to yield
Speaker 1: big rewards for you might have some good tasty morsels
Speaker 1: in there, or it could turn out to injure or
Speaker 1: kill you. Nature probably pays many animals to be conservative
Speaker 1: and avoid strange stimuli, better not to risk it. Right,
Speaker 1: But in the city animals can get big rewards by
Speaker 1: approaching a KFC bucket or an ice cream carton or
Speaker 1: other objects that would not they would not have natural
Speaker 1: instincts for or any previous experience with. So there could
Speaker 1: be cases in the cities where neophilia is positively selected
Speaker 1: for in a strong way, maybe breeding more bold, more
Speaker 1: curious animals. Well, I this brings me back to the raccoons.
Speaker 1: You know, the idea that the raccoon is bold in
Speaker 1: its uh, it's experimentation with some sort of a puzzle
Speaker 1: before it, you know, such as a KFC bucket. I
Speaker 1: mean a KFC buckets probably nothing to a raccoon. I'm
Speaker 1: sure they're well, they are well acquainted with the with
Speaker 1: the bucket of KFC at this point. Excuse me, Mr Lamb,
Speaker 1: we know about those. Um yeah, well, I guess maybe
Speaker 1: that should be it for today, right, and then we
Speaker 1: can explore more when we come back. We haven't even
Speaker 1: gotten deep into one of the most fascinating areas of
Speaker 1: urban evolution, which is birds. Yes, and then there's the
Speaker 1: whole we we talked a little bit about light earlier,
Speaker 1: but light pollution is another area with some very surprising
Speaker 1: adaptations that are occurring. We will explore all of those
Speaker 1: fascinating avenues the next time. And uh hey, while you're
Speaker 1: waiting for those, uh those new explorations, head on over
Speaker 1: to stuff to Blow your Mind dot com. That is
Speaker 1: the mothership. That's where you'll find this episode, all other episodes,
Speaker 1: including our episode on the London Underground mosquito, which is
Speaker 1: a fascinating look at a particular species that has adapted
Speaker 1: to an artificial human environment, that of the London Underground
Speaker 1: train system. Also at stuff to Blow your Mind dot com,
Speaker 1: you'll find links out to our various social media accounts
Speaker 1: such as Facebook, Twitter, Tumbler, and Instagram. Thanks so much,
Speaker 1: as always to our wonderful audio producers, Alex Williams and
Speaker 1: Tarry Harrison. If you would like to get in touch
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Speaker 1: episode or any other episode, to suggest a future topic,
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