Speaker 1: Tiger tiger burning bright in the forests of the night.
Speaker 1: What immortal hand or I could frame thy fearful symmetry?
Speaker 1: In what distant deeps or skies burnt the fire of
Speaker 1: thine eyes? On What wings dare he aspire? What the
Speaker 1: hand dare seize the fire? And what shoulder? And what
Speaker 1: art could twist the sinews of thy heart? And when
Speaker 1: thy heart began to beat? What dread hand? And what
Speaker 1: dread feet? What the hammer? What the chain? In what
Speaker 1: furnace was thy brain? What the anvil? What dread grasp?
Speaker 1: Dare its deadly terrors clasp? When the stars threw down
Speaker 1: their spears and water'd heaven with their tears, did he
Speaker 1: smile his work to see? Did he who made the
Speaker 1: lamb make thee tiger? Tiger burning bright in the forests
Speaker 1: of the night? What immortal hand or I dare frame
Speaker 1: thy fearful symmetry? Welcome to Stuff to Blow your Mind
Speaker 1: from how Stuffworks dot Com. Hey, welcome to Stuff to
Speaker 1: Blow your Mind. My name is Robert Lamb and I'm
Speaker 1: Joe McCormick. And that was The Tiger by William Blake.
Speaker 1: That's right, classic poem and one that ties into today's episode,
Speaker 1: because we're going to be talking about predators like the tiger,
Speaker 1: and I do think some of the initials, initial concerns
Speaker 1: that we're gonna be discussing here, the initial questions about
Speaker 1: the nature of predators um are closely mirrored in this
Speaker 1: poem and some of the questions it's asking. So here's
Speaker 1: a this weekend strange religious beliefs, Robert, have you ever
Speaker 1: heard about the There is a Young Earth creationist idea
Speaker 1: among some Young Earth creationist Christians, an idea that the
Speaker 1: Tyranno source Rex was a her before. Have you ever
Speaker 1: encountered this before among Young Earth creationists or their literature.
Speaker 1: I don't mean personal now. I make it a point
Speaker 1: to avoid younger creationist thoughts on dinosaurs and prestricked creatures,
Speaker 1: to the point that I found such a book in
Speaker 1: a lending library once, and I took great pleasure in
Speaker 1: moving it directly from the lending library to the garbage
Speaker 1: where it belongs. Well, I mean, that's in some ways
Speaker 1: a noble task. This is a book peddling lies to children,
Speaker 1: but often with great illustrations. Well it makes them even
Speaker 1: more effective. But yeah, so so you're saying, like say,
Speaker 1: what now Tarrannosaurus rex was a her before that just
Speaker 1: runs countered everything that I've I've ever read. Now, I
Speaker 1: want to be clear, I don't want to be unfair. Uh.
Speaker 1: This is not generally a belief held among Christians or
Speaker 1: anything like this. This is specifically a subset of Young
Speaker 1: Earth creationists who believe this. But if you just google it,
Speaker 1: you'll find all kinds of fundamentalist literature arguing that the
Speaker 1: t rex and all other dinosaurs were herbivores. They ate
Speaker 1: exclusively plants, And to be very clear, this is false.
Speaker 1: All evidence points to the tarrannisa is Rex having a
Speaker 1: meat based diet. There's some debate actually over whether the
Speaker 1: t rex was primarily a hunter predator or was primarily
Speaker 1: a scavenger of dead animals, and we can come back
Speaker 1: to that in a minute. But morphological analysis of the
Speaker 1: t rex skull alone will tell you very clearly that
Speaker 1: this is a meat eating animal. It's got the teeth
Speaker 1: of a meat eating animal, it's got the skull and
Speaker 1: jaw shape of a meat eating animal. It looks like
Speaker 1: it was built for applying crushing bites to prey animals
Speaker 1: and then powerfully pulling its head to move the animal's
Speaker 1: body or to rip away flesh. Now, as for the
Speaker 1: question of whether these mighty therapod dinosaurs were primarily hunter,
Speaker 1: predators or scavengers, we discussed one strong piece of evidence
Speaker 1: that the therapod relative of the t rex, the Alisaurus,
Speaker 1: was a predator in our Kimbodian Stegasaurus episode. You remember
Speaker 1: that it was another weird intersection between religious beliefs and dinosaurs.
Speaker 1: But anyway, in that episode we talked about the allosaurus
Speaker 1: who clearly died from an injury in a fight with
Speaker 1: a stegosaur. It got a thagon miser spike right to
Speaker 1: the crotch, and the way the bone has been preserved,
Speaker 1: it's clear that that's what happened. This is the opinion
Speaker 1: of the paleontologist Robert backer Um that that it died
Speaker 1: in a fight with the stegasaur it and so of
Speaker 1: course that really makes it look like the allosaurus was
Speaker 1: a predator. It seems like it would be unlikely that
Speaker 1: a scavenger would get thagomized in the crotch like that,
Speaker 1: so it was trying to attack pray. But anyway, the
Speaker 1: question is why would somebody, for religious reasons believe that
Speaker 1: meat eating dinosaurs were actually herbivores. Like, I don't remember
Speaker 1: anything in the Bible about the t rex. Uh. So
Speaker 1: I've tried to look up the reasoning behind people who
Speaker 1: believe this, and it seems to be sort of a
Speaker 1: consequence of other beliefs. So the people who have written
Speaker 1: on this, they sometimes refer to a passage in the
Speaker 1: first chapter of the Book of Genesis. It's Versus thirty,
Speaker 1: and it says, quote, and God said, see, I have
Speaker 1: given you every herb that yields seed, which is on
Speaker 1: the face of the earth, and every tree whose fruit
Speaker 1: yield seed to you, it shall be for food. Also
Speaker 1: to every beast of the earth, to every bird of
Speaker 1: the air, and to everything that creeps on the earth
Speaker 1: in which there is life. I have given every green
Speaker 1: herb for food. And it was so. So that's a
Speaker 1: verse that generally says, hey, animals, time to eat some vegetables.
Speaker 1: And then, of course, also there seems to be more
Speaker 1: broadly a widespread belief that meat eating would represent some
Speaker 1: kind of compromise to the idea of the original creation
Speaker 1: of the world as perfect. It would imply that Eden
Speaker 1: was not truly a perfect paradise. Well, I guess it
Speaker 1: is kind of an interesting theological question, right, I mean,
Speaker 1: could could Eve have really messed things up all that much?
Speaker 1: If prior to the fall there were predators feeding on
Speaker 1: other creatures young, or you had parasite induced blindness occurring,
Speaker 1: or even something as victimless as a buzzard tearing into
Speaker 1: a dead antelope. These are I think, because these are
Speaker 1: nasty images, people tend to assume that like, oh well,
Speaker 1: if that were to take place, it would definitely foul
Speaker 1: the balance of creation. Yeah, if there were tigers in
Speaker 1: the garden, and then we can't possibly envision them as anything,
Speaker 1: but then to to try and imagine, say a tiger,
Speaker 1: Try to imagine a tiger in the garden of Eden.
Speaker 1: If it's doing anything other than what tigers do, then
Speaker 1: it just doesn't make sense. We we can't possibly imagine
Speaker 1: the tigers anything but what it is, because everything they
Speaker 1: are is a meat eater. To envision an herbivore tiger
Speaker 1: is to envision either a possible like downstream evolutionary form,
Speaker 1: something on the level of say a giant panda, or
Speaker 1: something so far back in evolution that it scarcely resembles
Speaker 1: a cat at all, like to put it in a
Speaker 1: frame of reference, here, the first terrestrial herbivore probably appeared
Speaker 1: on land about two two million years ago, and it
Speaker 1: would not have looked like a tiger. Now, to come
Speaker 1: back to the tiger by William Blake, one of the
Speaker 1: ideas that he's asking is just like to to be
Speaker 1: very literal with the poem, is how can the same
Speaker 1: god who made the lamb, the sweeten lamb also make
Speaker 1: this ferocious tiger? Did he smile his work to see?
Speaker 1: Did he who made the lamb make the um? The
Speaker 1: side note um for Blake, here we the humans kind
Speaker 1: of made the lamb, like we domesticated that that's kind
Speaker 1: of kind kind of our thing, whereas the tiger is
Speaker 1: really ultimately of the two animals, the more perfect, you know,
Speaker 1: vision of creation. If you want to get technical, Yeah,
Speaker 1: that's a good point. But but I think this is
Speaker 1: basically this poem and some of these younger creationist ideas
Speaker 1: are kind of emerging from the same thing, like how
Speaker 1: do we square carnivorous biology? How do we square predation
Speaker 1: in this kind of idealized version of life? Right? Well,
Speaker 1: the implication of this belief, whether stated or unstated, is
Speaker 1: that a perfect world would be a world without meat eating, right,
Speaker 1: no predators, no scavengers. Now, this is not going to
Speaker 1: be primarily an episode about the ethics of human meat eating.
Speaker 1: I think there are questions to ask about, you know,
Speaker 1: humans who know better, like what would be the correct
Speaker 1: choice of how to live? But I wanted to talk
Speaker 1: about this issue because I want to make the case
Speaker 1: for the practical necessity of carnivori in nature. How in reality,
Speaker 1: a world without predators and scavengers would not be a
Speaker 1: perfect world. It would probably be a much worse world,
Speaker 1: a world that we would not like at all for
Speaker 1: many reasons, and perhaps even worthy of being called a
Speaker 1: herbivorous hell. Predators and scavengers are important. They play an
Speaker 1: important role in food chains and ecosystems, and they play
Speaker 1: a role that we have plenty of evidence directly benefits
Speaker 1: human beings on Earth. We would not like this planet
Speaker 1: without predators and scavengers. But if you just observe the
Speaker 1: way we talk about them, the way they feature in
Speaker 1: our narratives, and the way we treat them in reality,
Speaker 1: you wouldn't know this was the case, right, No, No,
Speaker 1: you just did assume, yeah, that the tiger is this threat.
Speaker 1: I mean, clearly, it's the villain of the Jungle Book.
Speaker 1: How else are we supposed to feel about it? Yeah,
Speaker 1: And it's all there in our mythology. I mean, there's
Speaker 1: always like some kind of evil predatory animal or a
Speaker 1: monster that's some kind of bigger, messed up version of
Speaker 1: a predatory animal. Uh, and that we vilify and we
Speaker 1: cast as a thing that must be killed in order
Speaker 1: for us to survive. Yeah, I mean to go back
Speaker 1: to our episode on the first monster. What is arguably
Speaker 1: the first monster depicted in human artifacts, but a lion
Speaker 1: headed human. Yeah, exactly, it takes on. It's a human
Speaker 1: who has the characteristics of a predatory animal. And there
Speaker 1: are plenty of good reasons that predators and scavengers are
Speaker 1: often feared and that they do really frustrate people. And
Speaker 1: it goes way beyond just direct attacks on humans. I mean,
Speaker 1: one of the biggest problems, if you're going to consider
Speaker 1: real problems caused by predatory animals in the world, one
Speaker 1: of the biggest problems is livestock depredation. You know, as
Speaker 1: soon as we had animal agriculture, predators could prey on
Speaker 1: the herds of domesticated animals that we created, and that's
Speaker 1: a real like loss of wealth from the humans who
Speaker 1: maintain those herds. But then also we you know, there
Speaker 1: are other things like attacks on pets and hosting diseases
Speaker 1: and parasites, and these are real things that our motivation
Speaker 1: for humans. But we want to stress again today, a
Speaker 1: world without predators is not a world you want. So
Speaker 1: what happens when we intentionally or inadvertently, you know, wage
Speaker 1: a war of extinction against our betters in the food chain?
Speaker 1: Are betters? Yeah, and in many cases are betters. Let's
Speaker 1: explore a few examples with the caveat here that we're
Speaker 1: going to ignore cases in which humans have dealt with
Speaker 1: invasive predators, which is which of course can be difficult
Speaker 1: in and of itself, but he's ultimately an attempt to
Speaker 1: kind of balance the scales that we upset. Right by
Speaker 1: introducing a predator into a range where it's not originally been,
Speaker 1: we might be upsetting an ecosystem that was stable on
Speaker 1: its own. So in most cases, predator eradication efforts or
Speaker 1: general predator culling or control efforts, they stem from this
Speaker 1: human unbalancing of the natural environment, and it usually goes
Speaker 1: down about like this. So you have predators and prey
Speaker 1: and they live in an involved balance. Then humans come along,
Speaker 1: they move into the area. What do they do well,
Speaker 1: they start building stuff and expanding. That leads to habitat
Speaker 1: loss for the the natural organisms that live in the area,
Speaker 1: including the predators. And then predators are killed or driven
Speaker 1: off when they encroach upon human territory. And then humans
Speaker 1: are raised domesticated food species, and then predators are drawn
Speaker 1: to those food species, the lambs that that we have
Speaker 1: framed exactly. And then uh, and then the predators are
Speaker 1: killed or driven off as a result of it. Yeah,
Speaker 1: it creates a tough situation. I mean, we can look
Speaker 1: to two examples of it in today's world. For instance,
Speaker 1: in modern Botswana. Uh, there's this need to protect both
Speaker 1: valuable cattle and threatened lions species. Local cattle farmers frequently
Speaker 1: resort to violent retaliation against the predators. Uh. And then again,
Speaker 1: the lions themselves are endangered. They are only about thirty
Speaker 1: thousand lions left in the wild, right, so conservationists don't
Speaker 1: want to see the lions killed. But then again, if
Speaker 1: you're a farmer and lions are attacking your cattle, you
Speaker 1: can very well understand why the farmer feels that way, right. Uh. Now, incidentally,
Speaker 1: there's a there's a really interesting up potential solution. I
Speaker 1: don't know if you called a solution as much as
Speaker 1: maybe a band aid for the scenario that has been explored,
Speaker 1: but a conservation biologist, Dr Neil Jordan's has actually rolled
Speaker 1: out a program to paint eyes on the rear ends
Speaker 1: of cattle to help to rely on attacks. Uh not
Speaker 1: unlike anti tiger masks that you sometimes see in belief
Speaker 1: parts of India or also just sort of the naturally
Speaker 1: evolved use of eye spots on various insects. And there's
Speaker 1: evidence this is actually effective. Yes, there is some evidence.
Speaker 1: Uh Um. I reported on it, I want to say,
Speaker 1: like a year a year and a half ago, so
Speaker 1: I haven't checked in to see what the latest data is.
Speaker 1: But at the time, the data was encouraging that it
Speaker 1: was at least in the I mean at least for
Speaker 1: the short term, cutting down on some of these predation instances.
Speaker 1: That's really interesting. I mean that goes along with some
Speaker 1: of the advice that I know this is this is
Speaker 1: probably not blanket advice, so don't use this as your
Speaker 1: survival tactics. But I know, at least in some discussions
Speaker 1: about how to deal best with encounters of wild editors,
Speaker 1: like if you encounter I think maybe a bear or
Speaker 1: a mountain lion or something like that out in the wild.
Speaker 1: I've definitely heard advice before that you should not turn
Speaker 1: your back and run because that can very easily trigger
Speaker 1: you know, chase impulses. So what you want to do
Speaker 1: is remain facing the animal, make it clear that you
Speaker 1: can see it, and try to put distance between you
Speaker 1: and it, you know, backing away. Uh And and that
Speaker 1: sort of makes sense. I mean, an animal should be
Speaker 1: able to see where other animals are looking, and if
Speaker 1: it thinks you're not looking at it, that is a
Speaker 1: chance for an attack. Now, another good example or wolves.
Speaker 1: Wolves have face and continue to face a similar plight
Speaker 1: in North America. So humans trot out all of these
Speaker 1: domesticated prey species organisms that are really in many ways
Speaker 1: trapped in a perpetual adolescence, which is key because in
Speaker 1: the natural world that is where you see a lot
Speaker 1: of the predation. You see the predators preying upon the
Speaker 1: young or you know, the sick. But through domestication, we've
Speaker 1: made sure that these species are main ideal prey for us.
Speaker 1: So it's uh, you know, it's not a huge mysteries
Speaker 1: as to why their ideal prey for various obligate carnivores
Speaker 1: out there. Yeah, so the American gray wolf is this
Speaker 1: is I found this super interesting. It is the modern
Speaker 1: American wolf. Now what does that mean? So, as Carl
Speaker 1: Zimmer pointed out in a two thousand sixteen New York
Speaker 1: Times article on the subject, genomic evidence reveals that the
Speaker 1: Eastern wolf and the red wolf, previously you know, considered
Speaker 1: to be two separate varieties of wolf, those are actually
Speaker 1: just mixtures of wolf and coyote d nat so they're
Speaker 1: just their hybrids. But the one true wolf is the
Speaker 1: gray wolf. Well, I mean, it's been interesting to see
Speaker 1: as urbanization has happened throughout the United States, especially in
Speaker 1: the twentieth century, the way that wild carnivorous canids have
Speaker 1: adapted to human spaces. I mean, we we talked in
Speaker 1: our Urban Evolution episode about the coyotes of American cities.
Speaker 1: They're all over the place, and they they find ways
Speaker 1: of surviving alongside us that we barely even detect. So,
Speaker 1: as of two thousand seventeen, this is the most recent
Speaker 1: data as of this recording. Uh, they're roughly five thousand,
Speaker 1: six hundred and eighty gray wolves remaining in the lower
Speaker 1: forty eight states. That don't sound like that many. Now
Speaker 1: Alaska has between UM seventy seven hundred and eleven thousand,
Speaker 1: two hundred, but kind of lupus. The gray wolf once
Speaker 1: ranged from the Rockies to New England, and it's been
Speaker 1: victim been victim to antipredation efforts to protect livestock, um hunting, trapping, baiting,
Speaker 1: and some pretty pervasive scare tactics about the nature of
Speaker 1: the wolves themselves. Now, to be clear, wolf attacks have
Speaker 1: occurred in North America, but they are rare, and even
Speaker 1: when they do occur, Uh, there, you know they're not
Speaker 1: There's not just one type of wolf attack. You can,
Speaker 1: for instance, chalk some of them up to defensive attacks,
Speaker 1: and then also rabies could be a factor as well
Speaker 1: in some of these cases. Yeah, absolutely, But I mean
Speaker 1: the wolf is a perfect test case for people, uh
Speaker 1: to they can see what the danger of being near
Speaker 1: a wolf is. Like if you're told there's a wolf
Speaker 1: in your neighborhood, you can immediately envision like, oh, I
Speaker 1: can see how that could go bad. I could be
Speaker 1: out in the yard and a wolf could attack me.
Speaker 1: But you don't understand or easily visualize the other side
Speaker 1: of the equation what the downsides can be if there's
Speaker 1: not a wolf in your neighborhood. And indeed, there are
Speaker 1: many neighborhoods where they're they're not being no wolves, and
Speaker 1: sometimes those neighborhoods are something like Yellowstone National Park. Uh.
Speaker 1: It's an interesting case, and this was outlined by a
Speaker 1: science writer and rewilding advocate, George monbiat Uh. He points
Speaker 1: out that wolves were reintroduced into Yellowstone National Park in
Speaker 1: a Yellowstone that by that point was overrun by deer
Speaker 1: without predators to control their numbers, and the results were
Speaker 1: pretty amazing, he lays out, So they introduced the wolves
Speaker 1: back into into the park. The wolves, of course killed
Speaker 1: some deer, as would be expected, but then this also
Speaker 1: changed the behavior of the deer. The deer started avoiding
Speaker 1: essentially dangerous areas of the park, areas that were not
Speaker 1: a good place to to hang out in if there
Speaker 1: were wolves about, and these places began to grow again
Speaker 1: to regenerate. Tree hid here increased dramatically in some areas,
Speaker 1: he says, Uh, certain bird species moved back in uh,
Speaker 1: beavers and beaver numbers increased. And between the wolves changing
Speaker 1: the essentially the prey species landscape here and the beavers
Speaker 1: altering the ecosystem as well, UH, they both work to
Speaker 1: make room for other species to thrive. Wolves killed coyotes
Speaker 1: and and this allowed rabbit and mice populations to begin
Speaker 1: to rise, bringing in hawks, weasels, foxes, badgers carrying birds
Speaker 1: to discavenge. After all of this, bear populations also arose,
Speaker 1: in part because they were now more berries from the
Speaker 1: shrubs that actually were able to grow. And this is
Speaker 1: often expressed in terms of a top predator in an
Speaker 1: ecosystem being a keystone species is a species that's sort
Speaker 1: of like necessary to allow the rest of the ecosystem
Speaker 1: to thrive as it normally would exactly. And so in
Speaker 1: this example of what happens when you put a predator
Speaker 1: back in to an environment, we're essentially seeing environmental collapse
Speaker 1: in reverse. UH. What what we're talking about here is
Speaker 1: widespread trophic cascades. These are ecological changes that start at
Speaker 1: the top of a food chain, UH, and the spiral
Speaker 1: all the way down. So yeah, apex predators are not
Speaker 1: just monsters that live atop you know, a mountain of
Speaker 1: bones and feast on the you know, the riches of
Speaker 1: the things that it preys upon, and like some sort
Speaker 1: of storybook monster. Now that the mountain wilds have have
Speaker 1: evolved with it, and then for everything depends on the
Speaker 1: predators for balance. Yeah, there is a sort of mythological
Speaker 1: model of the predator as oppressor. It's almost like the
Speaker 1: predator is the tyrant king of the animal kingdom because
Speaker 1: it preys on other animals. But really the the oppressor,
Speaker 1: the tyrant ruler of the animal kingdom is the finitude
Speaker 1: of energy, is the scarcity of resources, and the predator
Speaker 1: is subject to that too. And you remove the predator,
Speaker 1: it's not the case that all other organisms necessarily do
Speaker 1: well if the predator is gone. Instead of what you
Speaker 1: find is that the tyrnt of energy scarcity and food
Speaker 1: resource scarcity and all of that expresses itself in new ways,
Speaker 1: begins to to oppress organisms in ways that didn't happen
Speaker 1: when the predator was there. Yeah. I mean, as we've
Speaker 1: touched on before, it's not like if you're they've ex predator,
Speaker 1: it's just fat city. Um. You know, the life of
Speaker 1: a predator also is filled with challenges and has a
Speaker 1: fragility to it. Yeah. I mean when you when you
Speaker 1: see an image of a predator chasing prey, you should
Speaker 1: think the praise life is on the line, but the
Speaker 1: predator's life is also very likely on the line. The
Speaker 1: predator needs that energy to to survive, and if they
Speaker 1: don't make a catch soon, they might not survive the
Speaker 1: next winter exactly. And that's not even taking into account
Speaker 1: humans hunting you towards extinction or making you know, exploited
Speaker 1: movies about you attacking you know, um um nude bathers
Speaker 1: or something. Yeah, I mean, I think about the vilification
Speaker 1: of sharks. Uh. I often think of the vilification of
Speaker 1: sharks as a thing in the past, you know. I think, like, okay,
Speaker 1: jaws came out, and then there was a brief period
Speaker 1: in which people saw sharks as these horrible human eaters
Speaker 1: that had to be destroyed. But I guess my general
Speaker 1: impression is things have gotten better in more recent years.
Speaker 1: A conservation mindset is caught on. People know better than
Speaker 1: to suggest we should just run around killing sharks and
Speaker 1: other marine predators. But that's not always the case, even recently,
Speaker 1: even beyond just pure poaching there have been public campaigns
Speaker 1: against shark populations and intentional efforts to kill sharks in
Speaker 1: certain areas. Robert, have you ever read about shark drum
Speaker 1: lines before this? No, but they sound pretty groovy. Yeah,
Speaker 1: they're not so groovy. This is the thing I didn't
Speaker 1: know about before I was reading about this. But it's
Speaker 1: uh so it's a lead ethal trap to capture and
Speaker 1: kill sharks. Just one example is I was looking at
Speaker 1: a paper from about how in the government of Western
Speaker 1: Australia decided that sharks represented a threat to human safety
Speaker 1: to swimming around beaches, so they elected to put out
Speaker 1: these drum lines to kill the sharks in those areas
Speaker 1: and protect human bathers. And basically the way it works
Speaker 1: is that you have an anchored buoy, and then the
Speaker 1: anchored buoy is connected to what's known as a drum
Speaker 1: line buoy, a floating buoy that itself has a a
Speaker 1: triggering magnet um and then it's got a hook that's
Speaker 1: baited and so the sharks go and bite the hook
Speaker 1: and then they get stuck, and then it sends off
Speaker 1: a signal to let people know, Okay, we've caught one.
Speaker 1: Uh And so yeah, there were just these traps set up,
Speaker 1: and there was a great controversy about it in Australia
Speaker 1: because there was obviously, you know, people were saying, like
Speaker 1: we we don't need to be killing sharks. Maybe it
Speaker 1: would be better to change the place as we swim
Speaker 1: than to just kill all these animals. Yeah, that does
Speaker 1: not sound good. I I was thinking of shark drum circles.
Speaker 1: That would be a different scenario. Well wait, now, if
Speaker 1: it's a drum line in that, in that like marching band,
Speaker 1: like marching drums, Yeah, well that would be good too,
Speaker 1: but not very groovy. That's more. You know, it's a
Speaker 1: little it's a little more straight laced. Yeah, you gotta
Speaker 1: be worried when sharks start doing military formations. But whether
Speaker 1: I mean, whether due to deliberate human persecution or not.
Speaker 1: Lots of predators and scavengers we know, have seen drastic
Speaker 1: declining populations in the past few hundred years. According to
Speaker 1: a study we're about to talk about by O'Brien and
Speaker 1: and co authors, leopards have vanished from about seventy eight
Speaker 1: percent of their historic range. African lions are on the
Speaker 1: decline outside of protected areas of twenty two vulture species
Speaker 1: on Earth seventeen or in decline due to human activities.
Speaker 1: So predators and scavengers are having a tougher time than
Speaker 1: they've ever had, which is dangerous. And one of the
Speaker 1: key points really this episode is that, yeah, you can't.
Speaker 1: It's not just the monster disappearing from but it kind
Speaker 1: of is you take the monster out of a story,
Speaker 1: and then how much of a story do you really have?
Speaker 1: If you take Grendel out of Bowolf? What do you have?
Speaker 1: You're left with just kind of a boring story about
Speaker 1: a rampaging psychopath. But if you and likewise, if you
Speaker 1: take the the apex predators out of the scenario here,
Speaker 1: then it then it results in this kind of environmental
Speaker 1: collapse that we've discussed. Well, here's what I'd like to say.
Speaker 1: I'd like to see an alternate version of Beowulf like
Speaker 1: John Gardner's Grendel. Except what happens is after Beowulf kills Grendel, uh,
Speaker 1: the deer that Grendel normally eat overpopulate the forest and
Speaker 1: they spread a lot of disease, and everybody in her
Speaker 1: off cars meat Hall dies because they all get tick
Speaker 1: born diseases. Right it, man, that's the realistic outcome. Well,
Speaker 1: maybe we'll explore examples like that when we come back
Speaker 1: from a break. Thank alright, we're back, all right. So
Speaker 1: I was looking at a paper in Nature, Ecology and
Speaker 1: Evolution published this year called the Contribution of Predators and
Speaker 1: Scavengers to Human well Being by Christopher J. O'Brien, Alexander Braskowski,
Speaker 1: Hawthorne Bear, Neil Carter, James Watson, and Eve McDonald madden.
Speaker 1: And so the basic idea of this paper is that
Speaker 1: it's a huge literature review. It looks at papers from
Speaker 1: you know, all over the place to try to find
Speaker 1: documented examples of ways that predators and scavengers make human
Speaker 1: life better or removing them demonstrably makes human life worse.
Speaker 1: And so they start off talking about how predators and
Speaker 1: scavengers provide lots of benefits to humankind and we rarely
Speaker 1: recognize this, like humans and wild predators have undergone a
Speaker 1: process of coadaptation in the past few thousand years, with
Speaker 1: some beneficial outcomes for both. But this state of co
Speaker 1: adaptation depends on human tolerance of these animals, and as
Speaker 1: we've seen, this tolerance is not given a lot of times.
Speaker 1: We'll put out the drum lines will do wolf culling uh,
Speaker 1: and without predators and scavengers our world would be much
Speaker 1: much worse. Ecological research has shown this in many ways.
Speaker 1: So for example, predators regulate the populations of herbivores below
Speaker 1: them on the food chain, which if allowed to grow unchecked,
Speaker 1: could easily overgraze and destroy plant species important to human life.
Speaker 1: Another thing is that scavengers consume and dispose of animal
Speaker 1: carcasses and organic ways that we do not want piling up. Uh.
Speaker 1: The loss of predators and scavengers can destroy ecosystems by
Speaker 1: causing quote a loss of plant species, diversity, biomass, and
Speaker 1: productivity that in turn effect disease dynamics, carbon sequestration, and
Speaker 1: wildfire risk and Robert this seems to be along the
Speaker 1: lines of what you were talking about with the wolves
Speaker 1: and Yellowstone. And then also sometimes you can estimate the
Speaker 1: health of an entire ecosystem simply by looking at how
Speaker 1: the top predators and scavengers are doing like they will
Speaker 1: be They will sometimes almost be like a data sheet
Speaker 1: you can check out to see what everything else on
Speaker 1: the food chain is looking like. And yet, as we
Speaker 1: mentioned earlier, lots of predator and scavenger species around the
Speaker 1: world are still in decline due to human behavior, including
Speaker 1: everything from poaching to culling, to ecosystem destruction and to
Speaker 1: climate change. And there are actually documented cases where people
Speaker 1: intentionally tolerate predators and scavengers, especially scavengers, because they're aware
Speaker 1: of their benefits. Like the authors talk about how uh scavenger,
Speaker 1: the scavenger of the Egyptian vulture. This is a bird
Speaker 1: species that's suffering and decline around the world, but there
Speaker 1: are places in Socotra, Yemen where they're doing well because
Speaker 1: the people are aware of the benefits they provide, specifically
Speaker 1: removing livestock and human waste, which if not removed, can
Speaker 1: cause water contamination. And that's no joke. The risks of
Speaker 1: water contamination due to waste runoff are serious, and this
Speaker 1: type of contamination is not just something that say, happens
Speaker 1: in Yemen. It can happen all over the world and
Speaker 1: often does. I found a New York Times article from
Speaker 1: two thousand nine by Charles do Hig about how the
Speaker 1: residents around Morrison, Wisconsin were sickened contamination of water resources
Speaker 1: from agricultural waste basically manure breeds, parasites and bacteria which
Speaker 1: flow into the groundwater. And to read a quote from
Speaker 1: that article quote in Morrison, more than a hundred wells
Speaker 1: were polluted by agricultural runoff within a few months, according
Speaker 1: the local officials, as parasites and bacteria seeped into drinking water,
Speaker 1: residents suffered from chronic diarrhea, stomach illnesses, and severe ear infections.
Speaker 1: And then they quote a woman living in the area
Speaker 1: who said, sometimes it smells like a barn coming out
Speaker 1: of the faucet. Now, that's that's not always as much
Speaker 1: of a bad sign. Robert, have you ever smelled like
Speaker 1: kind of FARTI smelling water from a faucet somewhere? Um,
Speaker 1: I mean, I guess sometimes you know, you're at the
Speaker 1: beach and the you know, beech water can have a
Speaker 1: certain odor. I'm not sure if I would say it's,
Speaker 1: you know, like a barn smell or anything, but I'm
Speaker 1: trying to remember the last place I was where the
Speaker 1: tap water was like that. But I've definitely smelled it before.
Speaker 1: It is a little disconcerting, even if you know it's
Speaker 1: probably safe. Like you go to brush your teeth and
Speaker 1: and it smells like toots for real. Zase has haunted
Speaker 1: your bathroom. I can't believe he's summoned toots for realities.
Speaker 1: But now, of course the reverse is also true. There
Speaker 1: are places where the water certainly seems appetizing, but it's
Speaker 1: not actually drinkable exactly. So anything you can do to
Speaker 1: manage runoff of dangerous waste running into water sources is big,
Speaker 1: and so a lot of times predators and scavengers, particularly
Speaker 1: scavengers can do that. Another example is the Tigray region
Speaker 1: of Ethiopia, which has spotted hyenas, and the humans of
Speaker 1: this region tend to tolerate them because the hyenas eat
Speaker 1: the carcasses of dead livestock as well as unburied human corpses,
Speaker 1: which reduces the risk of disease and the settlements, And
Speaker 1: so disease and human settlements is a big part of
Speaker 1: the benefits provided by predators and scavengers. Some of the
Speaker 1: biggest diseases were worried about in the world are zoonotic diseases,
Speaker 1: diseases that have animal vectors like the zekeovirus UH, strains
Speaker 1: of flu you know, avian flu, swine flu UH, the
Speaker 1: Ebola virus, lime disease, and so there are several ways
Speaker 1: predators can reduce chances that we catch diseases from animals,
Speaker 1: and one of them is by reducing the density of
Speaker 1: host populations. And so the way that works is this, um, say,
Speaker 1: it's flu season. You want to avoid catching the flu?
Speaker 1: Uh what? What what's a good day look like if
Speaker 1: you want to avoid catching the flu? Is it like
Speaker 1: going out to the cannibal corpse concert and washing in
Speaker 1: the pit? Or is it going for a walk in
Speaker 1: the woods by yourself? Uh? Well, if you don't want
Speaker 1: to catch the flu, yeah, go in the woods by yourself. Yeah, exactly.
Speaker 1: I mean density, literal population density, how much organisms of
Speaker 1: the conspecifics spend, how much time they spend around each other,
Speaker 1: how close they get, how much they contact the same surfaces,
Speaker 1: and all that that's directly related to the spread of
Speaker 1: the disease. And so if you reduce the density of
Speaker 1: a population, you reduce the rate at which the disease spreads. So, so,
Speaker 1: to go back to our our Yellowstone example, like, if
Speaker 1: you have the deer just um, just unopposed by predators,
Speaker 1: they're just hanging out all over with each other, and
Speaker 1: that that creates a more potential for something like this
Speaker 1: to take off. But if they're if they're patrolled by predators,
Speaker 1: then they're going to be perhaps more fragmented and fewer
Speaker 1: in number because of the members of their uh their
Speaker 1: species that are picked off by the predators. Exactly, thinning
Speaker 1: out the population of deer could potentially limit the spread
Speaker 1: of dearborn diseases. And then, of course there's also the
Speaker 1: more direct effect that if you limit the population of
Speaker 1: an animals ay dear, it will be less likely that
Speaker 1: any given human in the area is exposed to a deer,
Speaker 1: and thus less likely the disease spreads from the deer
Speaker 1: to the person. Just a few examples cited by the authors.
Speaker 1: One is that around Sanjay Gandhi National Park in India,
Speaker 1: leopard predation on dogs has greatly reduced the frequency of
Speaker 1: dog bites in the region and thus lowered the incidents
Speaker 1: of rabies transmission to humans. Researchers think that generalist predators
Speaker 1: like foxes can help protect people from lime disease by
Speaker 1: controlling populations of mice, since mice or a primary reservoir
Speaker 1: for ticks carrying the disease, and then we don't think
Speaker 1: to be thankful to frog tadpoles, but tadpoles probably play
Speaker 1: a really important role in limiting the worldwide risk of
Speaker 1: mosquito born diseases like dingay fever because they eat mosquito eggs.
Speaker 1: Of course, I mean we've we've kind of looked at
Speaker 1: this and from the opposite direction that like, you know,
Speaker 1: why do we have mosquito as well, because actually mosquito
Speaker 1: larva are an important part of many, uh many diets
Speaker 1: out there, And yeah, it makes sense too that you'd
Speaker 1: want the animals that eat those larva otherwise explosion of
Speaker 1: mosquitoes exactly. But also predators and scavengers can reduce our
Speaker 1: disease risk through a mechanism known as competitive exclusion, and
Speaker 1: this is basically out competing disease hosts for resources or territory.
Speaker 1: So an example here would be vultures sometimes outcompete stray
Speaker 1: dogs for the main scavenging niche in and around human settlements,
Speaker 1: and this can be a good thing for reducing stray
Speaker 1: dog bites on human and human exposure to rabies. And
Speaker 1: then sometimes removing natural predators and scavengers from a native
Speaker 1: ecosystem can lead to their automatic replacement by other predators
Speaker 1: and scavengers, which might be much worse for human health.
Speaker 1: For example, the author's right that scavengers can replace vultures,
Speaker 1: and the ones that replace them can include gulls, rats,
Speaker 1: and invasive foxes, all of which can pose risks to
Speaker 1: humans and can themselves be disease hosts because of its nature.
Speaker 1: If there's a meal to be had, something is going
Speaker 1: to get in and eat it, And if you wipe
Speaker 1: out the predator that's most highly evolved to deal with it,
Speaker 1: then somebody else is going to take a shot at it.
Speaker 1: Wouldn't you rather the the predator that's there to eat
Speaker 1: the meal be the one that the ecosystem is already
Speaker 1: adapted around, unless there's stability to the ecosystem. So there
Speaker 1: are tons of ways that predators and scavengers limit human
Speaker 1: exposure to diseases. But another thing that's interesting is the
Speaker 1: way that predators apparently increase agricultural output. I mean, a
Speaker 1: huge amount of agricultural wealth every year is lost to
Speaker 1: pest species that consume crops. The author is a side
Speaker 1: to study estimating that ten of global financial losses and
Speaker 1: agricultural wealth are due to animal species that come and
Speaker 1: eat the crops, and that that's a huge amount of
Speaker 1: lost wealth over the whole globe, and so current methods
Speaker 1: of preventing that kind of loss are not always great, right.
Speaker 1: They often consist of chemical pesticides, which frankly are something
Speaker 1: that that we're still studying and we don't know all
Speaker 1: of the negative effects of, you know, many years down
Speaker 1: the road. Yeah, but but I mean ultimately that the uh,
Speaker 1: the argument here is pretty simple, like, if something is
Speaker 1: eating your crops, what better way to prevent that from
Speaker 1: happening than having a naturally occurring predator to drive them off. Exactly,
Speaker 1: I'm trying to keep birds from eating all the figs
Speaker 1: in my fig tree, and all I have is like
Speaker 1: a fake owl to set up there next to which,
Speaker 1: Oh you have a scare owl? I do? Yeah? Or
Speaker 1: wait to scarecrow. You have a scarecrow owl? Yes, it's
Speaker 1: it's not a replican owl like the Fabulous Woman having
Speaker 1: Blade Runner. That one was too expensive, minds the ten
Speaker 1: dollar model. Its head doesn't even bob. But quick poll,
Speaker 1: do you have a favorite killer scarecrow movie? Oh? I
Speaker 1: mean they're all kind of terrible, aren't they. That's a
Speaker 1: subgenre that never really caught on, Like you might think, well,
Speaker 1: there's a lot of potential. They're they're they're they're so creepy.
Speaker 1: I mean, I guess I love the scarecrow batman villain
Speaker 1: if he counts. Oh yeah, he's a good one. Yeah
Speaker 1: he was. Well, I liked him in the animated series. Yes,
Speaker 1: he was a lot of fun in that too. Yeah.
Speaker 1: I guess there's some some scarecrow movies coming to mind,
Speaker 1: but I feel like it was a little icky. Oh yeah, yeah, yeah,
Speaker 1: that's the main one that sticks. They often tend to be.
Speaker 1: I what I'd much rather have is an actual owl, though,
Speaker 1: that would just live in my backyard and uh and
Speaker 1: scare away, you know, an appropriate number of predators. They
Speaker 1: can have some of the figs. I'm not greedy. I
Speaker 1: just want to make sure that I have some too well.
Speaker 1: I mean, predators like that are important not just for
Speaker 1: your own personal figs, but for for the crops that
Speaker 1: sustain economies and that that feed people and that are
Speaker 1: turned into animal feed and all that kind of stuff that,
Speaker 1: you know, the backbone of an agricultural economy. Like it
Speaker 1: has often been speculated by by researchers that species like
Speaker 1: bats and some birds are the most economically important non
Speaker 1: domesticated animals on Earth, and this is because of all
Speaker 1: of the pest control that they naturally do in the
Speaker 1: wild on pests that would otherwise eat all of our crops.
Speaker 1: And so the author's site research that indicates like the
Speaker 1: densities of pests like the corn earworm or the cucumber
Speaker 1: beetle can be suppressed by almost sixty percent by back communities,
Speaker 1: and bats can also help suppress the spread of fungus
Speaker 1: in corn crops, and so this leads to like real
Speaker 1: dollars saved and and predatory birds do similar things. They've
Speaker 1: been shown to be valuable in cocao plantations, saving more
Speaker 1: than thirty percent of crop output. Speaking of owls, the
Speaker 1: barn owl is a huge lifesaver when it comes to
Speaker 1: saving agricultural output um. Apparently, according to the authors quote,
Speaker 1: the barn owl Tito alba has a diet made up
Speaker 1: of about agricultural pest species in agricultural fields of California. Wow,
Speaker 1: barn owls are a great species to bring up in
Speaker 1: this because the barn owl, of course is normally going
Speaker 1: to set up shop and nest in um and it's
Speaker 1: essentially like a hollowed out tree or tree trunk kind
Speaker 1: of in a situation. But now they're co adapted. But
Speaker 1: that's right, they they they also are fine with sant
Speaker 1: abandoned barn because this also perfectly replicates the environment they need.
Speaker 1: But it's kind of a domino effect though, right as
Speaker 1: as humans expand, suddenly that there are fewer places for
Speaker 1: them to naturally build their nest. And if you don't
Speaker 1: have you know, empty barn sitting around, then they also
Speaker 1: don't have a place to build their nests. But this
Speaker 1: has led to many people to put up nesting box
Speaker 1: is for barn owls, which is essentially just a uh
Speaker 1: what it sounds like a box, like a mini portion
Speaker 1: of a barn that you can just put in the
Speaker 1: top of a tree to encourage them to roost their
Speaker 1: nice I've never heard of that. Yeah, there's a children's
Speaker 1: book about it that's reading it about it about it
Speaker 1: the other day with my son. Now, I will say
Speaker 1: I think probably barn owls are not vilified as much
Speaker 1: as some animals like wolves or Yeah, I think they're
Speaker 1: mainly suffering from you know, incidental habitat loss, which can
Speaker 1: be sufficient enough to eradicate a species. But yeah, they're
Speaker 1: not having a deal on top of that, with people,
Speaker 1: you know, essentially raising their pitchforks against the owls. But
Speaker 1: I mean when it comes to other noticeable larger predators
Speaker 1: like dingoes, even they apparently increase agricultural output, they help
Speaker 1: our farmers too, Like lots of animal. Ranchers obviously don't
Speaker 1: like carnivores like dingoes because sometimes they prey on their herds,
Speaker 1: but sometimes wild carnivores actually protect herds in pastures where
Speaker 1: there are also wild herbivores cause the dingoes or the
Speaker 1: other animals like that reduced the number of wild herbivores
Speaker 1: and thus reduce competition for grazing. So, for example, research
Speaker 1: in Australia is shown that the presence of dingoes can
Speaker 1: increase agricultural production by reducing populations of red kangaroo, which
Speaker 1: compete with livestock for grazing land. And a lot of
Speaker 1: times cattle farmers don't realize this and they'll kill dingoes,
Speaker 1: but it has been estimated the dingoes significantly increase output
Speaker 1: biomass per hectare of land. If you give rid of
Speaker 1: all the dingoes, then you're gonna have to deal with
Speaker 1: all these kangaroos. And what are you gonna do? Just
Speaker 1: keep killing and killing. Well, yeah, probably that's kind of
Speaker 1: what humans do. I guess it could be. Hey, when
Speaker 1: it comes to your garden. They signed a study by
Speaker 1: the way that says research has shown that skunks reduced
Speaker 1: pests in North American gardens and increase the yields of
Speaker 1: those gardens. So you need to get yourself some skunks. Well,
Speaker 1: I've certainly heard the argument for possums based in a
Speaker 1: large part on the number of I believe it's ticks
Speaker 1: that that that the average possible will eat, so they
Speaker 1: meant be much to look look at. But if you
Speaker 1: have a possum in your yard, it's potentially cutting down
Speaker 1: on on some of the pests you would have to
Speaker 1: deal with. Oh man, anything that will get rid of ticks.
Speaker 1: The enemy of my enemy is my friend, even if
Speaker 1: it's a possum. Uh. But what about the enemy of
Speaker 1: my enemy of my enemy, which is your dog or cat? Well,
Speaker 1: you know, collateral damage, I guess. But now this is
Speaker 1: a good point. This is why one of the reasons
Speaker 1: why my cat lives indoors. Now, yeah, I love dogs
Speaker 1: and cats, but I mean it is certainly true that
Speaker 1: that domesticated dogs and cats can really mess up an
Speaker 1: ecosystem if released upon the wild. Yeah, I think about
Speaker 1: this a lot. In our neck of the woods, we
Speaker 1: have a lot of feral cats, pretty common occurrence, I think,
Speaker 1: uh in North America. And yet yeah, they're they are
Speaker 1: they are super, They're little super predators are there in
Speaker 1: their own way, like they are able to just ravage,
Speaker 1: especially the bird population. When we had Jason or the
Speaker 1: local Atlanta Bird Exploding podcast, he talked to us a
Speaker 1: lot about the damage done by just releasing cats and
Speaker 1: letting them go outside. They're driving off our possums and
Speaker 1: they're not eating any of the ticks. It's a disgusting part.
Speaker 1: That's a good point. Why don't the cats just eat
Speaker 1: the ticks directly? That would be great, But of course
Speaker 1: they'll never comply anyway, So uh, we don't stop there. Okay.
Speaker 1: So predators and scavengers clearly reduced disease risk and disease
Speaker 1: spread among animals and among humans. They benefit agriculture, They
Speaker 1: apparently actually benefit human life in urban areas in plenty
Speaker 1: of ways. Like so, so there are plenty of things
Speaker 1: that cause humans and wild animals to come into contact.
Speaker 1: Of course, expanding human settlements and habitat destruction would be
Speaker 1: a big part of that. Yeah, do is to go
Speaker 1: hand in hand. But then, of course animals are often
Speaker 1: attracted to high calorie foods and shelter, and those are
Speaker 1: available in abundance and human settlements. But there are tons
Speaker 1: of ways that predators and scavengers in urban areas, even
Speaker 1: within human settlements, are beneficial, including removing waste and carcasses
Speaker 1: that this happens all the time, like golden jackals in
Speaker 1: Serbia apparently removed just tons of animal waste, including road
Speaker 1: killed animals and stuff like that. And then also you've
Speaker 1: got the fact that in many urban areas, natural predators
Speaker 1: control populations of other animals that directly cause harm to humans. Uh,
Speaker 1: here's a big one. You might not consider natural predators
Speaker 1: reduce wildlife vehicle collisions. Oh, this makes sense as well,
Speaker 1: because what are all these excess prey animals doing but
Speaker 1: running in front of my car? They often are, so
Speaker 1: the author's right quote. One study found that the potential
Speaker 1: recolonization of cougars over a thirty year period in the
Speaker 1: Eastern USA would reduce dear populations and thereby curtail dear
Speaker 1: vehicle collisions by twenty two percent. The authors estimated that
Speaker 1: this reduction and collisions would result in a hundred and
Speaker 1: fifty five fewer human deaths, twenty one thousand four fewer
Speaker 1: human injuries, and two thirteen billion dollars in saved costs.
Speaker 1: If those estimates are right, that's a heck of a
Speaker 1: lot of damage just caused by deer getting in front
Speaker 1: of your car. Yeah, and I have been in I
Speaker 1: have been in the vehicle, if I remember correctly, on
Speaker 1: two different incidents when I've the vehicle has hit a deer,
Speaker 1: there's some way, shape or form. In one case, the
Speaker 1: deer had already been hit and it was just like
Speaker 1: coming over a hill and there it was, and like
Speaker 1: the car went right over it. But uh, yeah, I
Speaker 1: feel like this is a this is an increasingly common
Speaker 1: occurrence if you're doing any amount of driving outside of
Speaker 1: an urban environment, and even even with within an urban environment,
Speaker 1: you're still facing the risk of those squirrels or you know,
Speaker 1: various stray animals that may be running out in front
Speaker 1: of your vehicle. Well, depending on what kind of urban
Speaker 1: environment it is there, there are still sometimes even deer.
Speaker 1: I mean, I think about how often you see deer
Speaker 1: in some cities in Tennessee. Certainly, one funny note that
Speaker 1: I that was in this paper was that apparently reintroducing
Speaker 1: predator ters can even reduce auto insurance premiums and affected
Speaker 1: areas because they, you know, reduce the risk. I wonder
Speaker 1: if I can contact my my insurance companies say, look,
Speaker 1: I introduced we introduced a mountain lion into my neighborhood. Up,
Speaker 1: can you bring my my premium down a bit? Plan
Speaker 1: on releasing wolves? How will that affect my rate? No?
Speaker 1: I bet they won't do it on an individual basis, unfortunately.
Speaker 1: But yeah, so we've got this issue where we know
Speaker 1: that predators and scavengers provide immense benefits to humans. Of course,
Speaker 1: they provide benefits to the ecosystems themselves, but they provide
Speaker 1: immense benefits to human economies, to human public health, all
Speaker 1: of that. And yet we are going to continue to
Speaker 1: have these conflicts because predators are sometimes ferocious. They will
Speaker 1: sometimes attack our domesticated animals and all that, they will
Speaker 1: sometimes attack humans as long as they're going to be
Speaker 1: humans and predators and scavengers in these shared zones, these
Speaker 1: sort of uh middle zones where both humans and predators
Speaker 1: can inhabit there will be these conflicts, and yet we
Speaker 1: don't want to eliminate them. So part of the question
Speaker 1: is how do you get people to understand that, even
Speaker 1: though occasionally there will be wolf attacks on people and
Speaker 1: stuff like that, that is massively counterbalanced by the benefits
Speaker 1: provided by these creatures. Yeah, you have to have to
Speaker 1: weigh all the benefits and not just you know, overreact
Speaker 1: to one media report about uh, you know, a predation
Speaker 1: scenario involving a human infant is as shocking and horrible
Speaker 1: as that can be. Um, you know, obviously, I mean,
Speaker 1: it's still not a reason to say set out to
Speaker 1: destroy all crocodiles or all wolves, right, And and part
Speaker 1: of the problem is that media reports can just even
Speaker 1: without intending to do it, sensationalized predators. Like the one
Speaker 1: thing I often think about is the type of media
Speaker 1: story that doesn't say we should kill all predators, but
Speaker 1: it just makes a media story out of predators citing
Speaker 1: in a human area, you know, because other a wolf
Speaker 1: in the neighborhood. Yeah, because otherwise, when is the shark
Speaker 1: making the news. It's making the news because it was
Speaker 1: seen in a human swimming area, a human caught it,
Speaker 1: or killed it, or the reverse happened. Of course it
Speaker 1: attacked or killed a human there. Yeah, there is no
Speaker 1: story about the thousands of sharks that swam by without
Speaker 1: anybody noticing them. And you make a good point that
Speaker 1: very often the point of conflict here arises because of
Speaker 1: human aggression, not because of the aggression of the animal,
Speaker 1: or even if it's not aggression. It's like if you've
Speaker 1: if we've all heard, you know, do not feed the
Speaker 1: wild animals, which is wonderful advice for a number of reasons,
Speaker 1: but if it's a if it's a prey species, especially
Speaker 1: if it's a species that that could potentially attack a human,
Speaker 1: then you should not do anything to to shrink the
Speaker 1: natural distance between our species, right. So, I mean, I
Speaker 1: think one thing in this space that's important is trying
Speaker 1: to find smart strategies, Smart strategies that don't involve just
Speaker 1: killing predators and scavengers outright because we don't like them,
Speaker 1: or because there was one unfortunate point of conflict between
Speaker 1: humans and whatever the species is that's local, but finding
Speaker 1: ways to try to reduce encounters between humans and humans
Speaker 1: in their livestock in these species while allowing the species
Speaker 1: to live the example you mentioned earlier with just like
Speaker 1: being able to paint eyes on the back of cattle,
Speaker 1: that that sounds like a brilliant example of a solution there. Yeah,
Speaker 1: make the make the the the the humans cattle less
Speaker 1: appealing slightly as the feeling maybe even. But then the
Speaker 1: reverse is well, the lions that are gonna hopefully go
Speaker 1: eat other things, other prey animals that are still allowed
Speaker 1: to reside in the natural environment. Yeah, of course not
Speaker 1: destroying natural habitats helps as well. Yeah, the to whatever
Speaker 1: to the more we unbalance the given environment, like, the
Speaker 1: more complicated it is to try and figure out what
Speaker 1: the new balance is, or certainly to try and achieve
Speaker 1: anything like the old balance. But anyway, if so, summary
Speaker 1: of all that, you've got the disease control, you've got,
Speaker 1: agricultural protection, you've got all these direct benefits on human life,
Speaker 1: like reducing auto collisions or disposing of waste. There are
Speaker 1: just tons of ways that predators and scavengers are benefiting
Speaker 1: your life and benefiting human civilization in ways that you
Speaker 1: don't even appreciate or understand that are completely invisible to you.
Speaker 1: But without them the world would be so much worse.
Speaker 1: And so I think we should just take a moment
Speaker 1: to appreciate the nasty animals. Indeed, here's to you, nasty animals.
Speaker 1: Let's take a break, and when we come back, you know,
Speaker 1: we'll talk a little bit about the nastiest animal of all.
Speaker 1: Thank you. Thank Alright, we're back. So we've been talking
Speaker 1: about how, even despite our mythologies and despite some religious
Speaker 1: beliefs and all, that a world without predation is probably
Speaker 1: not a good world. That's not a place where you'd
Speaker 1: want to live. Predation does so many important things. It
Speaker 1: plays an important ecological role. But I want to think
Speaker 1: about another way that a world without predation is probably
Speaker 1: not a world you want to live in because I
Speaker 1: have a hard time imagining how a planet that never
Speaker 1: evolved predation would ever evolve intelligence. Indeed, I mean it's
Speaker 1: difficult to imagine a human level or greater intelligence emerging
Speaker 1: in the absence of predation. Our best examples of non
Speaker 1: human intelligence are either predators that have to engage in
Speaker 1: advanced tactics and behaviors to catch prey uh and or
Speaker 1: utilize these skills to avoid predation themselves. And curiously enough,
Speaker 1: humans seem to stand as as an example of both. Yeah, exactly.
Speaker 1: I mean, almost everything we call intelligence, I think has
Speaker 1: something to do with time. Right. It has to do
Speaker 1: with the speed at which you your body does something.
Speaker 1: An organism that was able to avoid a you know,
Speaker 1: an oncoming object, but it took a thousand years to
Speaker 1: do so would you call that intelligence? Maybe? I mean,
Speaker 1: it seems like it'd be hard to do, but it
Speaker 1: seems to me like very much. An important part of
Speaker 1: what intelligence is is that it has to do with
Speaker 1: the speed of solutions to two problems, right, and the
Speaker 1: speed at yeah, the speed at which it needs to
Speaker 1: find a solution to that problem. Because something reacting at
Speaker 1: the level we're talking about, uh, you know, maybe not
Speaker 1: quite the same level, but you can look at an
Speaker 1: oak tree and say, well, the oak tree has its
Speaker 1: reflexes are not nearly as as quick as those of say,
Speaker 1: you know, a feral cat, but they are both effectively
Speaker 1: solving the problems that are necessary to to existing. Yeah,
Speaker 1: and speed just pretty much, it seems clear needs to
Speaker 1: exist in the world because predation exists. Right, It's kind
Speaker 1: of this this arms race of speedy reactions. Yeah, you know.
Speaker 1: In a fun bit of synchronicity, we recorded this episode
Speaker 1: the same week as our fiftieth anniversary celebration of two
Speaker 1: thousand and one A Space Odyssey. Yeah, and you know,
Speaker 1: the fourth first portion of that film, the Dawn of
Speaker 1: Man that we were discussing, you know, follows a population
Speaker 1: of hominids as they scrap by on hunter gathering existence,
Speaker 1: falling to predation from big cats from time to time,
Speaker 1: but then with a little help from an extraterrestrial sentinel,
Speaker 1: they take their first steps towards mastery of the planet
Speaker 1: and the use of weapons. Yeah, the monolith arrives, then
Speaker 1: they suddenly realize, hey, I can use a taper femur
Speaker 1: as a as a club. But before that, the big
Speaker 1: cat I believe it's a leopard in the movies, a
Speaker 1: real leopard attacking somebody in a in an ape costume.
Speaker 1: And it's frightening to watch, just and I'm not just
Speaker 1: saying it because I mean on two levels, because on
Speaker 1: one level the scene is very convincing, and then on
Speaker 1: another level, I'm thinking, oh, crap, that's a guy in
Speaker 1: an ape suit in a real carnivore has jumped on him.
Speaker 1: I can't help but have a like a primal response
Speaker 1: to that. Yeah, So fossil evidence does inform us that
Speaker 1: early humans fell to cave lions, two savor tooth cats
Speaker 1: and false savor tooth cats, but they were also eaten
Speaker 1: by other animals, including giant hyenas, eagles, snakes, other mates,
Speaker 1: and is. Rob Dunn pointed out in a two thousand
Speaker 1: twelve Slate article about about fear, we even felt a
Speaker 1: giant predatory kangaroos. Yes, the predatory kangaroos. Yeah, the occult
Speaker 1: occult of data. I believe it's it's called I've never
Speaker 1: even heard of this as far as I remember now.
Speaker 1: I'm embarrassed if you've told me on the show before,
Speaker 1: and I forgot. No, I do not think predatory kangaroos
Speaker 1: have come up before. And to call it a kangaroo,
Speaker 1: I've seen illustrations of what it might have looked like.
Speaker 1: And it doesn't straight up look like a thinged kangaroo
Speaker 1: or anything, but but still similar creature. So the Ovens
Speaker 1: seems to support the idea that that creatures like this,
Speaker 1: not just the kangaroo, but big cats, et cetera, feasted
Speaker 1: on human flesh so well into the most recent hundred
Speaker 1: thousand years of human history, and we see this reflected
Speaker 1: in the lives of modern primates as well. In places
Speaker 1: where large predators still haunt the shadows of primitive primate habitats,
Speaker 1: the young are still preyed upon, and where humans dwell
Speaker 1: alongside large carnivores, the young and occasionally even adults may
Speaker 1: fall to per day the world. That this world is
Speaker 1: also still reflected in our our our fight or flight responses,
Speaker 1: in the anxieties that we that define our lives, and
Speaker 1: in our nightmares and our fantasies and our fears. I mean,
Speaker 1: really we think back to that that a lion man
Speaker 1: the first monster, Like, it makes so much sense that
Speaker 1: that should be like the early the earliest known uh
Speaker 1: you know, physical manifestation of our fears that we would
Speaker 1: actually like craft that well. I mean, if you go
Speaker 1: by one thing we talked about recently as well as
Speaker 1: the idea of the hyperactive agency detection device, that is
Speaker 1: a hypothesis about you know, where are our a tendency
Speaker 1: to attribute agency to inanimate objects comes from? And but
Speaker 1: that says, you know, the things we really need to
Speaker 1: worry about there are two main things, animals and other humans.
Speaker 1: And if you combine the properties of the two, you've
Speaker 1: essentially got like the ultimate thing to be scared of.
Speaker 1: It's part human, it's part animal predator. It's both of
Speaker 1: the things that worry us the most. Now this is
Speaker 1: interesting too, because when we think about our our ancient ancestors,
Speaker 1: we do tend to think about these two things, right,
Speaker 1: warlike abilities towards self uh and and their ability to
Speaker 1: fight back against predators and of course prey on other beings.
Speaker 1: I mean everything was expressed in that opening uh a
Speaker 1: segment of two thousand and one of Space Odyssey. But
Speaker 1: some anthropologists, such as Robert W. Sussman, the late Robert W. Susman,
Speaker 1: I believe you passedway a few years ago. Uh. He
Speaker 1: argued that it was our that it was possibly not
Speaker 1: our ability uh to wage war against others, but rather
Speaker 1: our ability to cooperate with one another then enabled us
Speaker 1: to survive that era that we lived through as a
Speaker 1: prey species. Oh. I think there's tons of evidence that
Speaker 1: that social cooperation was a major factor in shaping the
Speaker 1: animals we are today. So there we were this this
Speaker 1: prey species barely hanging on, but then developing the social
Speaker 1: connections and the technology to fight back against predators to
Speaker 1: sort of overtime remove ourselves from full participation in the
Speaker 1: food chain. Um. And in doing so, we've become something
Speaker 1: more than just a predator. Uh. We've become kind of
Speaker 1: a super predator. As Sarah Zelinsky pointed out in a
Speaker 1: two thousand fifteen Smithsonian dot Com article, humans are unlike
Speaker 1: any other predator on the planet. Uh, and in in
Speaker 1: ways that that one might not instantly think. You know,
Speaker 1: obviously we use guns, and no other creature uses guns.
Speaker 1: You know, we we poison, we do all these other tactics.
Speaker 1: But everywhere else, predators prey upon the young, uh in particular.
Speaker 1: But humans kill healthy adults, especially when it comes to
Speaker 1: land carnivores and fish, and those adults, she she drives
Speaker 1: home in the article, these are the reproductive capital of
Speaker 1: the species. So you know these news stories that talk
Speaker 1: about the tragedy of someone being struck down in the
Speaker 1: prime of their life, Well, that's that's the sob story
Speaker 1: for most of the animals that humans kill. And while
Speaker 1: again that the natural predation model is for things that
Speaker 1: have not achieved that level um or they have fallen
Speaker 1: off on the other side, the young or the old,
Speaker 1: and this is especially destructive for long lived and late
Speaker 1: producing species. Of course. Yeah. One example of all this
Speaker 1: that Zelinski brings up is the stickleback. It's a fish
Speaker 1: that is just surrounded by predators. It just it has
Speaker 1: all the enemies, but the enemies mostly almost exclusively feed
Speaker 1: on young fries and subadults. Only five percent of the
Speaker 1: reproductively valuable adults are preyed upon each year. And that's
Speaker 1: a sharp contrast to commercial fishing, where fort of the
Speaker 1: biomass is netted and its predominantly real reproductive adults. So
Speaker 1: from like an energy and reproductive standpoint, our kind of
Speaker 1: hunting and trapping and fishing and all that is putting
Speaker 1: a different pressure on wild populations the normal predation would, yes,
Speaker 1: and maybe a pressure that those wild populations are not
Speaker 1: are not a position to sustain. Thomas rhym Chin of
Speaker 1: the University of Victoria research this uh this topic back
Speaker 1: in the nineteen seventies and found that while humans killed
Speaker 1: adult herbivores at about the same rate as non human
Speaker 1: predators quote, the harvest of adult carnivores by humans was
Speaker 1: nine times that of other large carnivores, which were mostly
Speaker 1: killing each other through competition, and the marine situation, according
Speaker 1: to Zelensky, is even worse, She says, marine predators harvest
Speaker 1: about one percent of adult biomass each year. Humans take
Speaker 1: a median of four and as much as or more
Speaker 1: in extreme cases. So yeah, technology not only allowed us
Speaker 1: to sort of escape from the food chain, it allowed
Speaker 1: us to escape from the limits of the natural prey
Speaker 1: predator dynamic. That's really interesting. So even while we can
Speaker 1: make the point that predators are good and predators are
Speaker 1: very important for ecosystem health and we should not be
Speaker 1: trying to eliminate them to make the world better, they
Speaker 1: are also very bad ways to be a predator. I
Speaker 1: mean you can see that even in non human animals,
Speaker 1: just when the wrong kind of invasive predator is introduced
Speaker 1: to an ecosystem and see the havoc at reachs. Right, Yeah,
Speaker 1: everything's out of balance. Yeah, but there can also be
Speaker 1: these these worldwide, world ranging super predators like us that
Speaker 1: just we don't play by the rules, right. We're playing
Speaker 1: with god code enabled, you know, which means we can
Speaker 1: just kill every creature on a level and not have to,
Speaker 1: you know, whereas otherwise the game mechanics would maybe dictate
Speaker 1: that you could only maybe kill thirty of the enemies
Speaker 1: on a given level. And actually make it to the
Speaker 1: end where the real ding goes. Yes, are the real
Speaker 1: thing goes. But but one of the big questions is,
Speaker 1: you know, what are we going to to be? You know,
Speaker 1: can we can we step down from the super threat
Speaker 1: predator throne? Can we actually uh implement more sustainable ways
Speaker 1: of of preying upon other animals in our world? And likewise,
Speaker 1: can we find more sustainable ways to deal with other
Speaker 1: predators that might be threatening the the the the environment
Speaker 1: that we have already unbalanced with our domesticated animals and
Speaker 1: our crops and our the expansion of our territory. You know,
Speaker 1: can we become something that's ultimately more, more humbler and
Speaker 1: more sustainable ourselves. It's a great question. I mean, how
Speaker 1: how to be a predator that knows it's a predator
Speaker 1: and recognizes its power. Yeah. There's a wonderful quote from
Speaker 1: George Mombia again, and this is from a two thousand
Speaker 1: fourteen Guardian article titled Destroyer of Worlds. He writes, is
Speaker 1: this all We are a diminutive monster that can leave
Speaker 1: no door closed, no hiding place intact, that is now
Speaker 1: doing to the great beasts of the sea what we
Speaker 1: did so long ago to the great beasts of the land,
Speaker 1: or can we stop? Can we use our ingenuity, which
Speaker 1: for two million years has turned so inventively to destruction,
Speaker 1: to defy our evolutionary history? I think we obviously can.
Speaker 1: The question is will we? I mean we we we
Speaker 1: have the ability to defy our evolutionary imperatives. We do
Speaker 1: it every time we do something self sacrificing for a stranger,
Speaker 1: or every time people use contraception or you know anything
Speaker 1: as so like we we certainly have the power to
Speaker 1: do more than just what is dictated by our genes.
Speaker 1: But the you know, in any given situation, will people
Speaker 1: do it? And that's the challenge. Yeah, that's the challenge today,
Speaker 1: That's the challenge going forward. But I think the it
Speaker 1: is important to put the emphasis on today as well,
Speaker 1: because it's all too easy just to say, well, it
Speaker 1: sounds like quite a problem. Hopefully somebody will figure that
Speaker 1: out in the years to come, or yeah, we'll get
Speaker 1: it where where humans are great, we'll figure it out.
Speaker 1: Hopefully we will. And I'm going to choose to be
Speaker 1: hopeful about it, because you know, I can. We can
Speaker 1: only act as as optimists if we're pestimist about it.
Speaker 1: Then what can we do? Yeah, and if you want
Speaker 1: to be optimistic about our future, can a predator like
Speaker 1: us uh learn to live within its means and reform?
Speaker 1: You've got to at least acknowledge the base fact that, hey,
Speaker 1: predators ain't so bad. Yeah, acknowledge that they have an
Speaker 1: essential role to play in our environment. And scavengers too.
Speaker 1: We shouldn't leave out scavenger. Yeah, the scavengers are also
Speaker 1: they are they're the clean up crew. They're less, less glamorous,
Speaker 1: but maybe even more useful. Yeah. All right, So there
Speaker 1: you have it, the predator, the scavenger. Uh. Well, hopefully
Speaker 1: this has UH forced you to re evaluate their roles.
Speaker 1: As always, check out stuff to Blow your Mind dot com.
Speaker 1: That's where we'll find all the podcast episodes. You just
Speaker 1: take a journey back through time there and listen to
Speaker 1: to uh a number of past episodes that have also
Speaker 1: dealt with biology and environmental issues and the future and
Speaker 1: past of our species. You also find links out to
Speaker 1: our verious social media accounts there, and hey, if you
Speaker 1: want to support the show, we urge you to rate
Speaker 1: and review it wherever you have the power to do so.
Speaker 1: Deep thanks, as always to our excellent audio producers Alex
Speaker 1: Williams and Tory Harrison. If you would like to get
Speaker 1: in touch with us directly to let us know feedback
Speaker 1: about this episode or any other suggested topic for the future,
Speaker 1: or just to say hi, you can email us at
Speaker 1: blow the Mind at how staff works dot com for
Speaker 1: more on this and thousands of other topics. Does it
Speaker 1: how stuff works dot com. B