Perhaps the most numerous species ever to have existed on earth, the passenger pigeon was a biological storm, an unparalleled natural phenomenon that truly embodies D&D’s swarm mechanic.

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Episode Transcript

Steve Sullivan: It’s a biological storm, fire that shoots across the skies. this magnificent pearlescent, skydiving bird. Passenger pigeons, as they passed over our head would darken the sky like twilight.

Stan Rachootin: It was said that they would blot out the sun when they would fly over you.

Steve Sullivan: The thundering of their wings would frighten horses. When they would land, sometimes their nesting colonies were miles square.

Stan Rachootin: And you hope you have an umbrella at the same time, too.

Steve Sullivan: The feces that they would drop would be so potent that it would destroy the trees that they were nesting on.

Stan Rachootin: In the 19th century, they are by far the commonest bird in the world. And today?

Lucas: Welcome to Making a Monster: Extinction. This is the companion podcast to Book of Extinction, a “monster manual” of animals lost to the natural world, but given a second life through Dungeons and Dragons. Natural history is already a part of the DNA of fantasy games. Many of our favorite monsters began as tall tales of exotic animals.

Bringing extinct species into D and D is one way to honor their memory and move people toward action in the climate crisis and accelerating mass extinction. We covered the story of the passenger pigeon a little in the introduction to this series. But in this episode, I get to show you how I turned it into a D and D monster for Book of Extinction.

If you want to follow along with this build, you can go to scintilla.studio/extinction right now to download a digital preview of the book, which includes a stat block for the real passenger pigeon, as well as the magical version we’ll be creating at the end of the show.

Our guides this episode are Steve Sullivan, director of the Hefner Museum of Natural History at Miami University.

Steve Sullivan: First of all, to define extinction: functional extinction is when all possible reproducing individuals of a species are gone. If we look at the passenger pigeon as an icon, when that one female passenger pigeon, Martha, was left alive in the Cincinnati Zoo, the species was not “extinct,” we might say in quotes, but in fact it was. It’s functionally extinct. Now extinction tends to be accepted as meaning no individuals of that species exist on the planet.

Lucas: I’d also like you to meet Stan Rachootin, Professor Emeritus of Biological Sciences at Mount Holyoke University on a tour of the Beneski Museum of Natural History at Amherst college in Amherst, Massachusetts. It was recorded in April of 2019.

Stan Rachootin: And we can start with this one, the passenger pigeon. Now, if you’re reading in the middle of the 19th century about anything about nature and people, lots of people talk about passenger pigeons. Darwin writes about them. Wallace writes about them. But the thing that’s important about passenger pigeons in the 19th century, they are by far the commonest bird in the world. Incredibly, incredibly large flocks of passenger pigeons.

North America before European Settlement

Steve Sullivan: So let’s sit back and look at North America prior to 1914. In fact, let’s look at North America prior to the 1600s. There were certainly people here. They were certainly managing the forests in very sophisticated ways. In fact, Ohio is pretty neat because as Ohio is covered in trees, and there are a handful of prairies here and there. From what we understand, the prairies that are in Ohio are anthropogenic – that is to say they were created by humans. So the Native Americans that were here recognized the value of diverse habitat and have what we call edge habitat. That is the habitat that is right between the forest and the prairie, that edge where things like to live. So they would go in, they would burn trees or otherwise get rid of trees, which would encourage prairies to occur.

So from what we understand, all of these prairies were created by Native Americans early on. So the forests were managed, but the feel was very much like a tropical rain forest. Think Mirkwood. Sometimes deep, dark dense, frightening to some people. Some of the trees there, the chestnuts, were 12 people linking arms in diameter, so big that a family that moves in, a family of colonists, could live inside a tree while they’re busy building their log house or their sod house, or clearing their fields or whatever.

Stan Rachootin: What were passenger pigeons doing that they could have so many huge, such huge flocks of passenger pigeons? What do passenger pigeons eat? Well. They are, they are strong fliers. They are flying all over the place.

Steve Sullivan: In fact, there’s a record of a passenger pigeon being shot, I think it was shot in either New York or New Jersey, and the contents of its crop, the place that it stores its food before it goes into its stomach to be ground up, the contents of its crop contained fruits that were only fruiting in Florida on that day. That shows you how far and how fast they can fly. There are estimates that they’re flying as much as 60 miles an hour, maybe more.

Stan Rachootin: Other birds? No. That it would be very difficult to have a flock of a billion birds that are going “Oh, okay, I see a lot, I see us sparrow, let’s go guys!” And then the billion birds dive down onto the sparrow. You know, or even an ostrich at that point, you know, you, you know, you’re not going to get very far with that. No, their specialty was acorns.

Steve Sullivan: The composition of this deep dark forest was oaks, that we’re very familiar with that drop acorns; various kinds of, of hickory and pecan and walnut, these large shelled nuts; then beech trees. Beech trees have very small fruits. The trees are towering with this smooth silvery bark. It’s it’s frankly, the bark that people like to vandalize when they’re on hikes, you know you’re in a beautiful, pristine place when the beach trees are smooth, like elephant skin, rather than scarred with “so-and-so loves so-and-so 1992.”

Beech trees are still around, but they’re not as common. But in earlier times, if you’ve heard of things like beech nut gum, or, beech nut baby food, things like this, it was recognized that beech nuts are really important because nuts in general are very fatty and calories are expensive. It’s only become, in recent decades, basically my lifetime, that calories have become so cheap and easy to get ahold of. So when beech nuts would, would have their, their fruits, what we call masting, it would be an unusual time.

A bunch of nuts? They’re for the birds!

Stan Rachootin: And acorns do something called mast. Mast fruiting is when oak trees decide and tell each other and they’ve not let us in on their code, we’re all gonna make a vast number of acorns just this season.

Steve Sullivan: They don’t mast every year. They mast when they’re they have enough energy and then they put all their energy into creating hundreds of nuts, ankle deep from as far as you can see, beech nuts everywhere.

Stan Rachootin: And so I’ve been here long enough in my 140 years at Mount Holyoke. In the last 35 years at Mount Holyoke, there’ve been about three or four years where you walk around Upper Lake and it feels like you’re out in, you know, in World War One and they’re shooting machine guns at you from all directions, because there are so many acorns falling all over the place.

And then you walk around in a normal year, around Upper Lake of ping, ping, ping, ping, ping. You know, you hear the acorns falling, but it’s not hundreds of acorns falling every, you know, every 10 seconds.

Steve Sullivan: So people would scoop those up. Native Americans, colonists would scoop those up, and use them as a protein source. And importantly, they lack tanins. And so we can eat them. Now, have you ever had a walnut that just, you know, at like Christmas time when people are sitting around shelling walnuts, but then, and it just makes your mouth pucker? Or worse yet, take a little nibble of an acorn. There’s a reason we humans don’t use acorns as food, but squirrels do. They have so much tannin in them. It’s like you take all the teabags in your, in your box, you soak them in your, in your teacup, you boil that down and for a day, and then you try to drink that? Your mouth is going to pucker up and that’s from the tanins..

Stan Rachootin: So the mast fruiting, why would the oak trees be into mast fruiting? Does anybody eat acorns? Squirrels, chipmunks, deer, mice, deer, all the things that carry Lyme disease. Deer mice and deer. So a big year for acorns, that’s going to be followed by a big year for deer mice and a big year for Lyme disease. So, you know, it really gets under your skin in some way or another.

Steve Sullivan: Now, as passenger pigeons are skimming that cream of nuts off the top of things, passenger pigeon are suppressing deer mice.

Now there’s a hypothesis – this is a difficult hypothesis to substantiate, but it’s, people are working on it – there’s a hypothesis that as, passenger pigeons in New England are skimming the beech nuts and acorns, they’re suppressing the deer mouse population. The deer mouse population is suppressed, that means the tick population is suppressed. That means the Lyme disease population is suppressed. That means Lyme disease, wherever it evolved, has to stay localized. As soon as we lose the passenger pigeon due to human caused extinction, deer mice now have all that food to eat, which means they’re reproducing nearly monthly and their babies are spreading everywhere with ticks. And now all of a sudden humans are not only getting chronic fatigue syndrome and other maladies they’re even becoming allergic to meat in some cases, because of these diseases that are being carried and it may be able to trace its roots back to the extinction of the passenger pigeon.

Stan Rachootin: But in a year that no one, no predator of acorns can predict, there are vast numbers of extra acorns. There aren’t enough weevils or deer mice or deer or chipmunks to do much damage to them. That’s the year the acorns will be able to germinate because there’s so many extra.

Steve Sullivan: So if there are these nuts, like beech nuts, like black walnuts, like pecans that have low tannins, we humans really want to use those. The other nut that was there was the chestnut and it’s extinct thanks to a fungal blight that kills them from the ground up. So these trees that were 12 men linking arms in diameter, they’re gone.

However, they were so huge. even though they’ve been extinct for a century now they’re still sending up shoots and trying to grow. But as soon as they get above ground, every so often they flower and fruit, but then they die because the fungus that exists only from the ground up. So here’s, this is the ecosystem that we’re looking at with passenger pigeons.

Lucas: That was a journey. Um, okay. Okay. I’m with you.

Stan Rachootin: Okay. And, and all the oak trees get the message that we’re going to do it together that same year, but nobody else has gotten in on the message. And so nobody knows, oh, this is the year I should have 20 extra babies because you know, we’re going to get to September and there’s a vast amount of food for getting us through the winter. So a lot of the acorns just survive.

A single organism with many eyes

Steve Sullivan: So the environment, the passenger pigeons are living in is this dense, dark, human-managed but massive forest, like Mirkwood, that includes trees that today over there, this one is masting. It’s producing tons, literally tons of fruit, but then for the next four or five years, nothing. But next year, the ones over there are fruiting. And so passenger pigeons develop as what we call cream skimmers. This is a group of organisms that can come and take the best things and then fly away. We see this in say African antelope, when the grass is tall and green and, and very nutritious, some species will come through, but then eventually the grass dries and becomes very short. There are other species that will be able to take advantage of that. And these two species, the ones that are gleaners and the ones that are cream skimmers, they cannot survive off of one another’s food. We see this with horses all the time. If you feed them too rich food, they actually get sick, they founder, they don’t function well.

So passenger pigeons are the species that just takes this cream off the top, and then it disappears. But how do you find the cream in Mirkwood forest when only 5,000 miles to the west is fruiting right now. And in a couple of weeks, it’s 3000 miles to the east. Well, what you do is you have lots of eyes that are looking and those eyes can move very fast.

Stan Rachootin: The trick of the passenger pigeons was, “We are willing to fly anywhere in North America, it has all oak forest everywhere, to find the forest that is doing mast fruiting. And then, yeah, I will settle down with 40 million of my closest friends and we’re going to eat all the acorns. And so we’re going to start at Missouri. And then if the next one is in Wisconsin, we’ll fly to Wisconsin. And then, okay guys, everybody up to Manitoba.”

And you know, you follow the season, you follow the acorns and everybody gets lots of acorns because you’re willing to go where the mast fruiting is. You’re strong fliers and you’ll find, and if you have that many of you out flying, you’re going to find the forests which are doing that.

Steve Sullivan: It’s the principle of satellites today. And so in this context, the passenger pigeon is not so much a species or an individual, the way that we often like to look at things. “Oh, what, what species of pet lizard do you have?” Or, “Oh, I like your dog so much.” In fact, the passenger pigeon is more like an ecological phenomenon. It’s a biological storm. Passenger pigeons, as they passed over our head here in Oxford, Ohio would darken the sky like twilight. Sometimes their nesting colonies were miles square.

The feces that they would drop would be so potent that it would destroy the trees that they were nesting on. It would over nitrogen them. Have you ever spilled nitrogen fertilizer on a lawn? It creates a giant brown patch of death. That’s what passenger pigeon poop is doing. And while they’re doing all this, they’re simply scooping up the beech nuts, scooping up these chestnuts much like the Chinese chestnuts that we get at holiday time in the grocery store. These are golf ball sized things. They’re just popping them down their throat and eventually digesting them. They’re also, sometimes they die in flight. So now they become this little fertilizer packet filled with seeds to help the forests grow back up.

Stan Rachootin: So where are we seeing a story like that in this class? Periodical cicadas? The 17 year cicadas, mass numbers of them, the predators can’t do anything with them are so many of them. And so they have the trees and the forest to themselves. And then 17 years later, there’s nobody around who remembers, oh, I remember no grandparent is telling the kids about the year of magic cicadas badges, cicadas, actually, uh, who came out and provided vast amounts of food for three weeks. You just can’t remember that because nobody in the forest around here lasts more than a couple of years.

So that was their trick. And then we came along and cut down all the oak trees and put in corn and wheat and so the passenger pigeons, who have one egg per mating for every time they mate, and will only feel comfortable mating surrounded by several thousand of their closest friends doing the same thing. So you put 14 of them in a single cage in the Cincinnati Zoo, they look at each other and say, “Okay, we all take vows of chastity.” And then they die one after another. And that was the end of them in the early 20th century.

Steve Sullivan: Look around the country. How many places are named after pigeons? They’re not named after city pigeons, who have their native range in the Mediterranean Sea. Those are named after our unique species, the passenger pigeon, as the French say, you can criticize my French accent, the pigeon de passage, Ectopistes migratorius, the migratory pigeon.

Pigeon Forge, Tennessee? Passenger pigeons. And frankly, it’s rich because of passenger pigeons. All that passenger pigeon poop? It may have killed the trees, but it also increased the productivity of the soil over the years. Next door over there in Gatlinburg, they could only grow, say, two or three ears of corn per given unit .Over there in Pigeon Forge, they could , grow five or six or 10 years of corn in the same area. So now they have time for banking and for commerce and for art. This is not necessarily a true historical example I’ve given here of these places, but it’s the kind of example that you get when passenger pigeons poop and die in a place, it becomes more rich like that. And so all these pigeon places they’re named because pigeons were so important, this biological phenomenon of pigeons.

Lucas: Dungeons & Dragons already has a name for this phenomenon: a swarm. Usually these are Medium, or roughly person-sized, swarms of Tiny creatures, but that’s completely inadequate to describe the “bird-nado” of a passenger pigeon swarm. We’re about to dive into designing this creature for D&D.

You are not the Villain in this Story

But before we do everybody take a deep breath, because at this point you might be thinking, “Man, people suck”. So far, everyone I’ve told this story to has said some version of that to me. In fact, you might describe your feelings as a “generalized sense that the ecological foundations of existence are in the process of collapse.”

There’s a name for that now. The American Psychological Association recognized it as “eco-anxiety” in 2017. And I have stared at my bedroom ceiling unable to sleep because of this feeling. It’s not a medical diagnosis, but it is a rational response to what’s happening and the best way to respond to it, to relieve that anxiety, is to take action.

Every conservationist I’ve spoken to on this project believes that “people suck and we’re all going to die” is not just the least helpful response you can have, it’s flat wrong. People are amazing. Our decisions as a species, society, and yes, as individuals change the face of the world, decide what lives and what dies, and that means we can choose life. The technologies and solutions to preserve habitat and biodiversity already exist, and they’re getting better by the day. So here are two ways you can take action in the climate crisis.

Center for Biological Diversity

First, donate to conservation through Book of Extinction. Go to scintilla.studio/extinction, or follow the link in the show notes to go to the Mage Hand Press store and download the preview of Book of Extinction. You can pay what you want for it, and whatever you pay will be donated to the Center for Biological Diversity to preserve endangered species, habitat, and biodiversity.

Second, share these stories with the people you play games with. Just telling people these animals existed and what they represent begins to reverse the sliding scale of decreasing biodiversity by helping people to realize what we’ve already lost. The Book of Extinction preview has short articles on the real world history of these creatures alongside the in-game lore I’ve written for fantasy worlds where magic is a selective pressure. So it’s a great way to talk about it.

You can also recommend this podcast. We get to spend the better part of an hour on each animal and go into way more detail than I could fit into a monster manual style entry. All right, everybody. Okay, stick around to the end of the show to hear about the de-extinction project for passenger pigeons. For now, let’s make a monster.

Passenger Pigeons as a D&D Monster

In the fantasy world of D&D, passenger pigeons would be called “The Feathered Tide”, a swarm of Tiny birds guided by a single instinctual mind. For starters, let’s talk size. Creatures in D&D are either Tiny, Small, Medium, Large, Huge, or Gargantuan. Medium is the size of an average humanoid and occupies a one inch square on the game’s grid at a scale of one inch to five feet. Tiny is half a square, or anything under two and a half feet by two and a half feet. So this would include a single passenger pigeon. Gargantuan, the game’s largest size category, is anything that covers a floor space of 20 feet by 20 feet or more.

We know from Erol Fuller’s book The Passenger Pigeon that roosting sites could cover anywhere from a few acres to hundreds of square miles, the largest being recorded at Sparta, Wisconsin in 1871 at 850 square miles. Pretty much the entirety of Sparta’s surrounding county to a depth thick enough to break the limbs off of trees.

So we know Gargantuan is inadequate. But how inadequate exactly? It’s time for pigeon math! So first we got to figure out the volume of a pigeon. A 1995 study on bird collisions with aircraft measured the volume of rock doves or domestic pigeons, both when dry and wet, in order to determine their density, which is just such a gift to the world. And I know it didn’t have my name on the tag, but it feels like it’s for me somehow. So we know that the volume of a modern domestic pigeon is 498.5 cubic centimeters. Let’s assume that the passenger pigeon is the same and that the swarm occupies exactly a 20 by 20 by 20 foot cube instead of a sphere or some random murmuration. Let us further assume a cubic pigeon, which would occupy this ludicrous cube in the most efficient way possible.

Under these conditions, a Gargantuan swarm of passenger pigeons would contain 453,977 birds.

Half a million isn’t quite the billions we need to represent the species in its prime, but it’s a good place to start. So how does this swarm obtain this kind of biomass? This is D and D. So the answer is magic. Of course. The feathered tide has a feature called “create passenger”: Any Medium or smaller beast that enters the swarm’s space or starts its turn there must make a DC 14 Wisdom saving throw. On a failed save, the beast is magically polymorphed into a passenger pigeon and absorbed by the swarm. The swarm gains half the beast’s current hit points, rounded down, which is the only way the swarm can regain hit points or heal itself. On a successful save, the beast is immune to this effect for the next 24 hours. So this swarm will be absorbing other birds, cattle, livestock, or wild beasts potentially up to, and including the biggest beast currently in the game, the Tyrannosaurus Rex, so bye bye Sue, I guess. It forces them to become a passenger pigeon to survive. It’s a new take, I think kind of consistent with modern zombie stories where loss of identity is one of the major themes explored. It’s also as much as I prefer to avoid this dichotomy, a kind of “us or them” statement. Once again, from Fuller’s previously cited book, “The plain truth is that the lives of the Passenger Pigeons and technological humankind were incompatible.” Which brings me back to de-extinction.

De-Extinction: Necromancy in Real Life

Stan Rachootin: There are no living passenger pigeons, although people are making arguments. Do we have enough of their DNA kicking around in dried up specimens that we might be able to get one, you know, get some made up again? Uh, maybe, maybe not.

Steve Sullivan: So a lot of times when we talk about extinct species, I’m often asked about de-extinction. In my parents’ generation, that was unthinkable. Watson and Crick, that was what, 1952, when we discovered, what DNA looked like thanks to their, piracy, a little bit of Rosalind Franklin’s work? Uh, but, uh, however that history happened, we finally understood really not just that as Alfred Russell Wallace and Charles Darwin showed, that species can change, but we then also began to understand the genetic makeup of how things could change.

And now today, with, with CRISPR technology, we can kind of cut up genes and chuck new bits in there. And, in fact with the mammoth, that’s been in the news recently, we can take Asian elephants and we can take some of these, frozen mammoths that have been in the permafrost for so long, which thanks to climate change, the permafrost is thawing, so we’re able to find these, but so well-preserved, we can even eat the meat. We can find the genes within those organisms. We can splice them into Asian elephants, and it is entirely conceivable that we can make a mammoth.

Stan Rachootin: So I think this is gonna probably be harder to do this one than to do, uh, mammoths because mammoths, we have a lot of DNA and Indian elephants are really close to mammoths.

Steve Sullivan: Now, there are some technical hurdles to overcome and some biological hurdles to overcome, but, you know, Star Trek was conceivable back when the technology was inconceivable and nowadays we’re kind of like, yeah, I guess we’d just have to find enough titanium on some asteroid to finish making the main saucer. So we can at least conceive that this could happen.

How is De-Extinction Done, and Does It Work?

There are a couple of ways that we can accomplish de-extinction. One is, as I’ve said, the sort of transgenics, and we can sort of fill in the gaps of a, of an existing species so that it becomes the extinct species. With the passenger pigeon, there have been proposals to take the band tailed pigeon, which is from a taxonomic perspective, probably the closest relative of the passenger pigeon, and to simply cut out the parts that make it distinctly band tailed pigeon, and plug in the parts that make it distinctly passenger pigeon.

In fact, um, years ago, I was managing a collection where we donated a very small sample of passenger pigeon tissue to a program that was analyzing their genes. And, you know, we can, we now have the sequence. We can create that sequence out of functional amino acids. We could plug that in. So some of that technology literally exists and the hurdles need to be overcome.

And to some extent it’s a matter of time, expertise, and the money to pay for it. Now the question comes, let’s say we’ve achieved de-extinction. So if I de-extinct a pigeon and it hatches out in my hand and it’s this so homely, it’s cute little altricial bird. And it grows up to this magnificent pearlescent, skydiving bird, and there’s one of them. And I’ve got it in a cage in my lab, or I’ve got in a cage in a zoo, or I’ve got it in an aviary. Maybe I’ve got a hundred birds. At what point have we actually de extincted the passenger pigeon? Are we going to be okay with passenger pigeons, thundering across the sky, maybe 10 times a year, maybe no times a year, who knows when, pooping on all our cars, ruining our paint jobs, making our cities stink for a time? Are we okay with that biological phenomenon today?

So the answer is yes, de-extinction is awesome. The other answer is de-extinction is problematic and we still need to have a big community conversation about it. I would say that passenger pigeons, even when a real one can perch on my hand will never be de extincted as I’m calling it now.

Lucas: Special thanks this episode to Fred Venne and the Beneski Museum of Natural History at Amherst College for contributing the recording of professor Rachooti’s tour. Thanks also to Steve Sullivan at the Hefner Museum of Natural History, whose storytelling skill and passion for conservation education are a gift to this project and the world.

Thanks for listening to Making a Monster. If bringing D&D to conservation matters to you, please visit scintilla.studio/extinction to download the Book of Extinction preview. You can pay what you think it’s worth, or you can just have it, but whatever you pay through that page will be donated to conservation efforts to preserve endangered species, habitat, and biodiversity.

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Next Episode: The Great Auk

The great auk is a powerful bird with a bone-chilling extinction story. It’s getting a second life as a D&D monster.

Extinction: Passenger Pigeon, the Feathered Tide