Joshua Ginsberg 0:18
It is just a wonderful thing to have Doug back. The work he does is so important. And I think we are as a community catching up with him. Right. He's been advocating for 20 years for these things, and more, probably, and I think it's just such a pleasure to have somebody who is so deeply involved with a renaissance of what we think of when we say backyard. So Doug, thank you for coming.
Doug Tallamy 0:52
Thank you, Josh. Great introduction. I'd love my high school teacher, English teacher, to hear about what a good writer I am; I think she might challenge that. Okay, we've got a lot to talk about, you know, actually, everything Josh just said is what I'm going to talk about; so do you have any questions? We can review, though. Nature's best hope, this is, I'm going to tell you about my idea of what nature's best hope is. And I'll give you a spoiler: you are nature's best hope. So I'm really going to tell you about why I think you are nature's best hope. And if there's stress for chairs here, there's two empty ones right down in front, right here.
And before I do that, let's talk about what E.O. Wilson's idea of nature's best hope was. Of course, he's, talking about a really famous professor, he was the most famous entomologist, pharmacologist, ecologist, conservation biologist. E.O. Wilson did it all, for more than 60 years at Harvard, he died the day after Christmas two years ago. But one thing that was consistent throughout his very long career was his love of life on Earth and his efforts to save it, not just because he loved it, but because he knew it was essential to our own survival. So in 2016, he wrote this book, Half-Earth: Our Planet's Fight for Life. And he had one simple message. If we're going to save life, anywhere on planet Earth, that's a very bold statement, if we're going to save life anywhere on planet Earth, we're going to have to save nature, we're going to have to save functioning ecosystems on at least half of the planet. And he spent most of the book talking about the science that supports that very bold statement. And then he ended the book, he didn't spend a lot of time telling us how we were going to save nature on half of planet Earth.
Of course, to a conservation biologist, that's a great idea; we'll just put half the Earth aside and everything that's in trouble can be in that half. And we humans will be in the other half. Half of terrestrial Earth is already in some form of agriculture, so I don't think we're going to change that. We've got 8 billion people and all of our airports and roadways and detritus in the other half. And we don't have a third half to put aside for nature. So people are wondering how we can actually do that. And that's really what I want to talk about today. Because I do think we can do that. I think we can realize E.O. Wilson's dream. But we do need a new approach to conservation to do that.
Before we talk about that, though, let's talk about what happened in 2019. And it's actually happening again this year in a lot of places, having a very large oak mast. Members of the red oak group got together and decided to make their acorns at the same time, and that's what it looked like in a lot of places. Well, I'm easily entertained, so I took one of those acorns and I just stared at it, but I was rewarded because an insect started to chew its way out of the acorn. First, the two little hole for its head, then of course its head through there. And of course, its entire body through the hole. It was a tight squeeze. And when it popped out, that's a dangerous time for that insect larvae because it's good to eat; a lot of things are after it, so it gets to safety by wiggling and squirming beneath the soil surface; takes about 30 seconds. And once it's underground, it stretches in all directions and forms a chamber and within that chamber converts itself to a pupa and then surprisingly, stays in that underground chamber as a pupa for two years. After two years comes out as an acorn weevil. That's what an acorn weevil looks like. A lot of people think weevils have big noses because it looks like they do; that's actually an extension of the head capsule, and the mouth parts are way down there at the end of that extension. They take those mouth parts, chew a hole into the center of the acorn, turn around and lay an egg in that hole and that is how the larva gets into the acorn.
Well, why do they spend two years underground? Why don't they come out the next year the way most insects would? Well it takes red oak acorns 18 months to complete their development. So if they came out the next year, there wouldn't be enough acorns for them. Of course, after they leave the acorn, leaves a hole. It's kind of like a true vacuum. You know that nature abhors a vacuum and in this case she's filled it with three species of Temnothorax ants; tiny little ants where the entire colony lives in the holes made by acorn weevils after they have left the acorn. And if scouts find a new acorn or a new hole in a new acorn, they get all excited because their old acorn's falling apart. So they tell everybody it's time to move, grab the larvae, grab the eggs, move the entire colony into the new acorn. It takes about 30 minutes. Then they post a guard there, make sure nobody else comes in. And that's where they live for the next two years until that acorn falls apart.
So what's my point with this little story? That's just one of literally millions of very specialized interactions that comprise the bulk of nature, largely between animals and plants. This is another one: relationship between Jays and acorns. Jays are the primary disperser of oak acorns. They'll take an acorn, fly a mile, mile and a half from the parent tree, they tap it below the soil surface. And the object is, you're gonna go back in the wintertime and have something to eat. But for every four acorns they bury, they only remember where one is. So for every four acorns they bury, they've actually planted three oak trees, and a single Jay can bury 4,500 acorns every fall. So they're planting a lot of oak trees. Specialized relationship between pileated woodpeckers and carpenter ants. That's what they rear their young on; carpenter ants. So you won't have pileated woodpeckers unless you have a lot of carpenter ants. And you won't have a lot of carpenter ants unless you have the big trees that make those carpenter ants. You won't have this bee, Andrena phacelia, unless you have phacelia; that is the only pollen that that bee can rear its young on. And it turns out that pollen specialization is very common among our native bees. We've got 3,600 to 4,000 species of native bees, and over a third of them can only reproduce on the pollen of particular plants. We won't have the Baltimore checkerspot unless you have white turtlehead. I could talk for a long time about nature's specialized relationships. But the point I want to make this evening is that those relationships, many, most of them, are in trouble. As a matter of fact, nature itself is on the ropes these days. And it's on the ropes because we didn't take Teddy Roosevelt's advice.
Way back in 1908, Teddy heard that the state of Arizona was going to mine the Grand Canyon. So he went to the canyon, looked out over the edge, and he said, "leave it as it is." And with those five words, he started the process of creating the Grand Canyon National Park. Well, we didn't leave most of the country as it was. There's only about 5% of the lower 48 states that's anything close to its original pristine ecological state. And those are typically mountaintops. And that's because we have logged the country repeatedly. We have tilled it, we have drained it, we've grazed it, got 770 million acres of range land out there--that's four and a half times the size of Texas--dedicated to cattle. And then, of course, we paved it, or otherwise developed it. We have straightened our rivers and dammed them, you can spell that any way you want. We polluted our skies and changed our climate for centuries to come. We've drained our aquifers. We've introduced more than 3,300 species of plants from other continents, many of which are running amok in our natural areas. In short, we've carved up those natural areas into tiny remnants of their former selves, and each one of those remnants is too small and too isolated to sustain the amount of nature that we humans need because it is nature that keeps us alive on this planet. So why have we done that? I don't know. But I suspect we thought that our nest, planet Earth, was so large, we could foul it forever, and there wouldn't be any consequences.
But of course, we were wrong about that, and that's where we're seeing some pretty scary headlines these days. Like, "The Insect Apocalypse Is Here: What does it mean for the rest of the rest of life on Earth?", talking about global insect decline. Followed by this one: "North America has lost 3 billion breeding birds in the last 50 years." That's a third of our North American bird population already gone. The U.N. is predicting that we will lose a million species to extinction in the next 20 years, and they made that prediction two years ago. So now I guess it's the next 18 years. It's a prediction. But it's one that we have to make sure it doesn't happen. Because those are the species that keep us alive on this planet. So I could go on talking about the pox that we humans have delivered upon the environment. And as Shakespeare says, upon all of our houses, that's not what this talk's about. This talk's about a cure for that pox. It's a cure that will take small efforts from lots of people, people like you and me. But those efforts will deliver enormous physical, psychological, and environmental benefits to everybody.
Doug Tallamy 9:13
Let's return briefly to this headline, "The Insect Apocalypse Is Here: What does it mean for the rest of life on Earth?" Well, back to E.O. Wilson; he told us what it would mean if Earth lost its insects. And he did it way back in 1987, with this paper, "The Little Things That Run the World." And again, his message was very, very clear. Life as we know it depends on insects. And if they were to disappear, so would most of our flowering plants, and if that happened, the energy flow through our terrestrial ecosystems would be so disrupted that the food webs that support our vertebrate animals, our amphibians, our reptiles, our birds, and our mammals, those food webs would collapse and those animals would all disappear. The biosphere, the living portion of the Earth, would rot because we would have lost insect decomposers that rapidly turn over nutrients and all we would have is bacteria and fungi.
And of course humans wouldn't survive any of those drastic changes. There is some good news. And that is that none of that has to happen. We can save our insects, we can save our birds, we can save nature itself. But we're going to have to change the way we landscape in order to do that. Why is that? Well, remember, humans are products of nature, we are totally dependent on the life support that ecosystems provide. We call them ecosystem services. These are just a few things that plants do that we depend on every day, like oxygen, plants are producing the oxygen we breathe; they're cleaning our water, slowing its journey to the sea where it becomes too salty to use; capturing carbon, enormously important today. Plants, of course, build their tissues out of carbon dioxide, the carbon in carbon dioxide, which they pulled out of the atmosphere out of harm's way. And then they pump the extra carbon that they harness into the soil. Forty percent of the carbon that plants pull out of the air ends up in the soil, where it's extremely stable, can stay for thousands of years. Plants are building topsoil, they're holding it in place. They're preventing floods, they're dampening severe weather, they're converting sunlight into food. If we lose our plants, we're going to have to eat sunlight. And that will be an IT challenge. What do animals do for plants? They provide pest control services, they pollinate nearly 90% of our flowering plants, they disperse plant seeds, and many other things.
So designing landscapes like this, that destroy the production of ecosystem services, just not a good idea. Never was a good idea, but just hey, it's terrible idea, because of those 8 billion people that are demanding more and more ecosystem services every single day. Now we do have parks, and we do have preserves, and they're doing the best they can. But we're in the sixth great extinction event that the Earth has ever experienced. So obviously, it is not good enough.
The simple solution is now to practice conservation outside of parks and preserves on landscapes just like this. There have been visionaries through the ages who have recognized that we humans needed to work on our relationship with planet Earth, and Aldo Leopold was one of the most eloquent; he wrote extensively in the first half of the 1900s. One of the things he said is the oldest task in human history is to live on piece of land without spoiling it. There have been Indigenous groups have been good at doing that for long periods. But our huge Western societies and our huge Asian societies are terrible at doing that. We habitually take more from the Earth than it has to offer, completely wrecking an area, going to another area doing the same thing, not sustainable behavior. But Aldo Leopold had a lot of faith in humans. He believed we were capable of developing what he called a land ethic. He knew we had to use the land, we had to farm and lumber and graze and mine and do all of those things. But he believed we were capable of learning to do them gently enough that we did not destroy local ecosystems. That's what he called the land ethic. And he wrote about it in his most famous book, The Sand County Almanac. What he did not write about though, was developing a land ethic where we actually lived. And I'm not sure why that was. But I suspect the notion that humans and nature cannot live together, we cannot coexist in the same place at the same time. That notion was so deeply embedded in the culture of Aldo Leopold's day, still embedded in our own culture, he may not have recognized it as an option.
But what I want to argue this evening is that not only is living with nature an option, it is now the only viable option that's left to us. In the past, of course, conservationists worked pretty much exclusively where there weren't a lot of people; we now need to turn that on its head and practice conservation where there are a lot of people because that's pretty much everywhere. And that means we've got to find ways for nature to thrive in human-dominated landscapes; not hang on by thread, not get diminished every day, but thrive.
So where should we start? Well, back to private property. Most of the country's privately owned: 78% of the U.S. is privately owned, 85.6% east of the Mississippi is privately owned. If we don't practice conservation on landscapes like that, we're going to fail. And we can't afford to fail. That's not an option. So when I use the word conservation, I'm not using exactly the way I mean, we do want to conserve any bits of nature that are left out there. That has been our conservation model for the last 100 years and we want to certainly keep doing that. But it's not enough. We have to move beyond conservation into restoration. We've got to rebuild landscapes that we've already destroyed by putting nature back. And people will say, "Well, gee, there's no way you're going to put it back exactly the way it was before we dismantled it," and they're right. But we can reunite enough of those specialized interactions that comprise the bulk of nature to form functioning ecosystems again, even if it's not exactly what was on that space at some point in the past. But to do that in a successful way, we have to start with the building blocks. Not all species contribute to ecosystem function equally. So we have to start with the most powerful groups and there's two groups we can't do without. One is the flowering plants and, of course, the pollinators that allow those plants to reproduce. They are capturing energy from the sun and, through photosynthesis, turning it into the simple sugars and carbohydrates, which is the food that supports just about all the animals on the planet. So now we have the food that supports animal life stored in plant parts, mostly leaves. But turns out that most vertebrates don't eat plants directly. Most vertebrates eat something else that ate plants, invertebrates that ate plants, and not just any invertebrate, they're typically insects, and not just any insects. It turns out that caterpillars are transferring more energy from plants to other animals than any other type of plant eater. So if we designed landscapes that don't have a lot of caterpillars in them, we're going to have failed food webs and eventually failed ecosystems.
I'm going to use the Carolina chickadee as an example. That is the chickadee that is in our yard in Oxford, Pennsylvania; you've got the Black Capped Chickadee up here doing pretty much the same thing. There of course the birds at our feeders all winter long eating seeds; we tend to think that is all chickadees need. Well, even in the wintertime only 50% of their diet is seeds. The other 50% is insects and spiders, even in the wintertime. And when it comes time to reproduce, their babies can't eat seeds at all. They're not exceptions. Most baby birds cannot eat seeds, so they switch to invertebrates. And if they're in a healthy environment, they will rear their young exclusively on caterpillars. And they are not alone: 96% of our terrestrial birds rear their young on insects, and most of those insects are caterpillars.
So what is special about caterpillars? There's actually several things special about caterpillars, and one of them is that they're soft. Think of this guy as if he's a little sausage with a very thin wrapper. The thin wrapper is his cuticle, it's his exoskeleton, it's made of chitin. It's undigestible. And because they're soft, you can stuff them down the throat of your offspring without fear of injuring them. And if you've ever watched a parent bird rear their young, they're pretty rough. Beaks like a plunger, they just stuff it down there. They're also relatively large prey items. One medium-sized caterpillar is equal to the biomass of 200 aphids. And some of our smaller birds do chase aphids around, but do you want to chase 200 aphids, or get one caterpillar? They're nutritious, they're high in fat, high in protein, low percentage of chitin, of exoskeleton, compared to most other insects, particularly beetles. Beetles are not like little sausages, they're like little tanks. So much of a beetle's undigestible and a lot of beetles have very sharp edges.
Doug Tallamy 17:43
I need a little drink of water here. Excuse me.
Doug Tallamy 17:51
I'm getting old. Finally. It'll come back, it'll come back. Caterpillars. Who else wants to give this talk? It's a little tickle. Caterpillars are the best source of carotenoids for birds during the breeding season.
Doug Tallamy 18:21
Then I'll choke the whole time. It really will go away; this happens now and then, just try to ignore me while you're listening to me. I mentioned carotenoids not because I love organic chemistry. Now I'm crying. I mentioned carotenoids because I'm a vertebrate. And you're a vertebrate, and we vertebrates cannot make our own carotenoids. Only birds. Only plants make carotenoids.
Doug Tallamy 18:54
This doesn't usually happen. So carotenoids, we need carotenoids because we can't make our own and we need to get them from plants because carotenoids are essential components of vertebrate diets. So where are the birds getting their carotenoids from? They are getting them from, of course, the prey items they're bringing back to the nest. But look, carotenoid content is not equally distributed among bird prey items. These first two bars are types of caterpillars. They have far more carotenoids than other types of bird prey. Here are the adult caterpillars right here, the moths and butterflies themselves. They have far fewer carotenoids because they're not eating the green leaves; that's where the carotenoids are. And there's the earthworm way over there. So the early bird gets the worm and he doesn't get any carotenoids when he gets the worm.
So that study and several others are suggesting that caterpillars are not optional parts of bird diets. They are essential parts of most bird diets. So let's just say most birds need caterpillars. The next question, and it's an important one, is how many caterpillars do they need? Is one or two enough, or one or two a day enough? Let's get back to chickadees. Carolina chickadees. There's a lot of data on Carolina chickadees. How many caterpillars does it take to make a nest of chickadees? One or two is not enough, one or two a day is not enough. It takes thousands, 6,000 to 9,000 caterpillars, depending on the number of chicks in the nest, to get that nest full of chicks to the point where they leave the nest, where they fledge. And then after they fledge, the parents continue to feed them caterpillars another 21 days, but they're flying all around so nobody can count all those. So you're really talking about tens of thousands of caterpillars required to make one nest of a bird that's a third of an ounce. That's four pennies worth of bird.
And do you want chickadees to breed in your yard? And I would think you do because in so many places, that's all we have, is our yards; you have to have all those caterpillars in your yard. Because chickadees and most birds are foraging very close to the nest about 50 meters from the nest. They're not flying five miles down the road to the nearest woodlot. And if we landscape in a way where there are not all those caterpillars in our yards, that's called insect decline. And it's really looking like insect declines are one of the major causes of the bird declines that people are measuring. We went to the original dataset of Rosenberg et al.; that's the Smithsonian group who said that we've lost 3 billion birds in the last 50 years. And we have divided the terrestrial bird species up into two groups: the species that require insects at some point of their life history, typically when they're when they're breeding; and the species that do not require insects. So things like doves and finches and crossbills can actually make a little nest or a little milk out of the seeds that they eat and that's what they rear their young on. So they don't require caterpillars. And look, they didn't lose any numbers at all in the last 50 years. But the birds that required insects lost on average 10 million individuals per species. It doesn't prove cause and effect. But it does suggest that as you take bird food away, you lose the birds. And look, it's not just not just birds that need caterpillars. This is the ornate box turtle in the Midwest, they used to be very common. They used to chase cutworm and armyworm invasions along; they need hundreds of caterpillars a day.
So there's a lot of things that depend on caterpillars, which means we need to raise the bar about what we're asking our landscapes to do. In the past we've asked them to do one thing: be pretty. Now we're going to ask them to do two things: be pretty and ecologically functional at the same time. And that's not going to happen unless we put the caterpillars back. So how do you do that? How do you put caterpillars back into your landscape? Well, you include the plants that support those caterpillars, which seems easy enough, but there is a catch. And that is that most plants do not support a lot of caterpillars, so we have to be fussy about it. We have to be fussy about which plants we're putting in our landscape and we have to be fussy about it because the caterpillars themselves are fussy about it. And the monarch butterfly illustrates that perfectly. You can have all of the Callery pear and all of the camellias and all the ginkgos and all the hostas and all of the privet and all of the porcelain berry; all the things I see that escaped in our natural areas here in our yards--all those ornamental plants from Asia, and you won't support a single monarch butterfly. The only thing is going to support a monarch butterfly is one of the milkweeds. That's called host plant specialization.
And it turns out that most of the insects that eat plants are host plant specialists just like the monarch. Why? Because plants have made them specialized; plants don't want to be eaten, they want to capture the energy from the sun and use it for their own growth and reproduction. So they've loaded their tissues with nasty tasting chemicals, secondary metabolic compounds that make those tissues either bitter, or downright toxic. And that's a really effective defense. It keeps most of the insects of the world from eating most of the plants of the world, which is why it's green out there, in the summertime. That's not because there's no insects out there that want to eat those plants. It's because most of the insects that are out there cannot eat most of the plants; they are too well protected. There's a reason it's hard to get our kids to eat their vegetables. They inherently know they're toxic.
But we do know that insects eat plants. So how do they do that? How do they get around these chemical defenses? Well, this is where the specialization comes in. Ninety percent of the insects that eat plants are host plant specialists just like the monarch; they can only eat particular plants for which they have adaptations that allow them to circumvent those chemical defenses. They need specialized enzymes that store and excrete and detoxify those compounds, behavioral adaptations and life history adaptations that minimize the insects' exposure to those compounds. But it takes a long period of evolutionary history with the plant lineage for all those adaptations to fall into place. And once they do, the insect's locked into eating that particular plant. So if you take the milkweeds out of your yard and replace them with hostas, the monarch's not going to be able to make a living on your hostas. It's got two choices then: fly away and find milkweed someplace else, or starve to death.
Turns out there's three kinds of plants out there: there are plants that contribute energy to local food webs. So remember, they're capturing energy from the sun, turning it into food, and then they pass it on, so that you have other things existing in that area, you have a viable food web. There are plants that don't do that; they're not contributing any energy to local food webs. And there are plants that actively remove energy from local food webs. Best example of a contributor in 84% of the counties in which they occur is one of the oaks. Got 91 species of oaks in this country, and they're contributing more energy to local food webs than any other plant genus by far. A good example of a non-contributor would be a ginkgo, a ginkgo biloba from Asia; it's a nice ornamental plant, turns a nice yellow color in the fall, but nothing eats a ginkgo so it's not adding any energy to the local food web. And a good example of a detractor would be Bradford pear, Callery pear, whatever you want to call it, or privet or burning bush or barberry; all of the things that we bring in, that have escaped our plantings. Not only are they not contributing energy to local food webs, but they're pushing out the contributors that native plants that do contribute. So they're removing energy from that food web.
So all I'm trying to say here is that plant choice matters. We're not going to be able to restore functional ecosystems if you don't have viable food webs in those ecosystems. And that's not going to happen unless we choose the right plants. And I'm going to give you three examples of how well it works when we do choose the right plants, starting with our house right here in Oxford, Pennsylvania. That's where Cindy and I live right now; we bought, there was a farm that was broken up into 10 acre lots, we got one of those lots, it was a very old farm; had been been farmed almost 300 years. And so the soil was exhausted, most of the topsoil was in a low area over there. And it had been mowed for hay before we moved in. So very little there and we wanted to rebuild this ecosystem. But we'd never done that before. I didn't know I wanted to see if we can get caterpillars to make a living on this landscape. So one of the first ones I tried to entice was the Canadian owlet. I'd never seen a Canadian owlet before. That's what the adult looks like; just like a leaf. People say, "Why did you choose the Canadian owlet?" I was looking through David Wagner's Caterpillars of Eastern North America; I said, "That's a pretty one, so."
Doug Tallamy 27:28
You're not gonna have Canadian owlets unless you have meadow rue. They are host plant specialists on meadow rue. We didn't have any meadow rue. We didn't have much. We didn't have any meadow rue, so I got some meadow rue seeds from someplace and planted it and they grew very nicely. But this was early on, I actually had very little faith that Canadian owlets would be able to find my little patch of meadow rue. So I didn't even go out and check it for about two months after I planted it. Then I was walking by for another reason I looked over and it was covered with Canadian owlets. They had found it right away. I'm still impressed with that. So now we got a good population of meadow rue and Canadian owlets, so we've added two species to the property. The restoration has begun. Same story with the goldenrod stowaway. That beautiful moth, actually it's a misnomer; has nothing to do with goldenrod. It's a specialist on this plant: Bidens aristosa, ditch daisy. We didn't have any Bidens aristosa. But I did know where there was some Bidens at a power line cut about 14 miles away. So I got some seeds, planted them at home. They grew very nicely. As a matter of fact, last year they took over our front yard. That's okay. Well, I had to wait a year for the golden rod stowaway to find our patch of Bidens, but they did. And now we've got a good population of both of those. So we've added four species to the property.
I want to see if the hackberry emperor could make a living at our house, not because it's the most beautiful butterfly in the world, but because it belongs there. It's one of the species that ought to be there. But as its name suggests, it's a specialist on hackberry, on celtis. We didn't have any hackberry, so I got a couple hackberry trees, I planted them. I had to wait four years for the hackberry emperor to find our hackberry, but they did. And now we've got a good population of both of those. So that's six species and that is how the restoration proceeded.
I did not plant goldenrod; it came in on its own. It, along with it, came many of the things that require goldenrod, like the beautiful brown-hooded owlet, the arcigera flower moth, the goldenrod leafminer, the distinct sparganothis, the goldenrod gall moth. There are 110 species of caterpillars that use goldenrod in the mid-Atlantic states, and that includes New York. I planted Virginia creeper. Yes, Virginia creeper. I know some people don't like it. But I don't know why; it's a great native plant, it's got good fall color, can climb our trees without girdling them, without pulling them down. Good ground cover, makes valuable berries for the birds in the fall. And by valuable, I mean they're high in fat, our migrating birds need sources of fat to fuel that migration. And our overwintering birds need sources of fat to get them through the winter. And those berries come from tiny little inconspicuous flowers; you don't even know the Virginia creeper's in bloom until you see this big cloud of native bees around. It's a wonderful pollinator plant.
Remember, when you're making a pollinator garden, you're making it for the pollinators. If it's not big and showy for you, that's okay. I planted a Virginia creeper because it's the best host plant of the large sphinx moths that are a primary component of cardinal diets, things like the Pandora's sphinx, and its beautiful adult. The lettered sphinx, the hog's sphinx, the abbot's sphinx, all on Virginia creeper. Wanted to see if I could get the double-toothed prominent to make a living in our house just because it's such a cool-looking caterpillar. Even if you don't like caterpillars, you gotta like that guy. Looks like a stegosaurus. Well, it's a specialist on elm; particularly American elm. And of course, we didn't have any American elm; that was wiped out by the Dutch elm disease decades ago. But there are two big American elms at the University of Delaware that did not die. And every year they make a lot of seed.
So I think the second year after we moved in, I gathered up some seeds from the gutter. People say it's so expensive to do this. No, just go to the gutter and get some seeds, plant them, and they germinate in six days. They grow really quickly. Today those trees are over 80 feet tall, and they did attract the double-toothed prominent. American elm. Wanted to see if I get the evening primrose moth to make a living in our house just because it's beautiful. I like beauty like anybody else. Well, we didn't have any evening primrose, believe it or not. So I planted some, the moth did come and spent a day with its head stuffed in the flowers. Sometimes it's crowded in there, but it's always very cute. And of course, I planted lots of oaks.
Now these are just examples of the plants that we put back at our house. I want to focus on oaks for a while because they are such important plants. That's the Bedford oak in Bedford, New York, you might recognize that; Martha Stewart land, people argue about whether it's 400 years old or 500 years old. It's enormous. And I do hear people say, "I'm not going to plant an oak because I won't live long enough to enjoy it." And if you can only enjoy it when it's 400 years old, you're right, you won't. But if you can enjoy what that oak is delivering to your local food web--remember, that's a new goal, now--you can enjoy it right away. And I can say that with confidence, because I planted most of my oaks as acorns, which means they were free, or two-foot bareroot whips, which means they cost $1.50 each. And immediately they started to call in the moths that make the caterpillars that run the food web at our house.
Things like the solitary oak leafminer, Juvenal's duskywing, the yellow shouldered moth, Suzuki's promalactis, the red washed caterpillar, the yellow vested moth, the orange tufted Oneida, the spiny oak caterpillar, the two spotted oak punkie, the variable oak leaf caterpillar, the red humped oak worm, the pink striped oak worm, the hesitant dagger moth, the lesser oak dagger moth, the medium dagger moth, the greater oak dagger moth, the street dagger moth, the afflicted dagger moth, the crowned buccalatrix, the orange-patched smoky wing, the white-blotched heterocampa, the oblique heterocampa, the red-lined panopoda, the laugher, and literally hundreds more species of caterpillars have come to the oak.
Doug Tallamy 33:04
I clap for oaks too, they're just the best, best hosts. And look, they come right away. This is a pin oak that just popped its head above the leaves, and there's a caterpillar standing on the ground eating the leaves of that tree. And people say, "oh, it's gonna kill the tree". No, an ovenbird is gonna come eat the caterpillar in the next 10 minutes. And that's how the food web works. So you don't have to wait decades or hundreds of years for your oak to start to contribute to the local food web, they will do it the very first year.
That's what our yard looks like taken from pretty much the same place I took that first picture. Because we put some plants back, not all of them, you know, we're still working on it. But my research has shown in the last 20 years that if, you know, if you understand the number of moths, number of moth species in your local food web--moths, not butterflies; butterflies are bad-tasting day-flying moths. And because they're bad-tasting, they don't contribute that much to local food webs, but the moths do, and if you know the number of species of moths in your food web, you have a very good index of how stable that food web is, and how complex it is, how productive it is. So that means how many species is it supporting. So six years ago, I started to take a picture of every species of moth I could find at our property. I am still doing it. But I'm up to 1,256 species so far that are there because we put the plants back. Now we do have 10 acres. Pennsylvania's 2.4 million acres. So on 1/240 thousandth of the landmass, we've got 48% of all the moths that occur in the entire state. And because so many of those are types of bird food, we have recorded 62 species of birds that have bred on our 10 acres; not flew by, but bred.
Why am I telling you this? Well, this is another headline you see all the time: "World Wildlife Fund says that two-thirds of Earth's wildlife have disappeared." It's a terrible headline. But I'm thinking, "gee, not at our house." I am convinced we have increased biodiversity by more than two thirds. It didn't take that long and it wasn't that hard. We just put the plants back. What would happen if everybody put the plants back? We really could turn headlines like this around. But Cindy and I have 10 acres; a lot of people have less land than that. Will it work on smaller properties? Let's say in suburbia. That's a really good question.
So let's go to Margy and Dan Terpstra's house in Kirkwood, Missouri. They have 0.6 acres; 18 times less land that Cindy and I have. They're in the middle of a development. Everybody around them has the big lawns. When they moved in, their entire property was choked with bush honeysuckle, Amur honeysuckle, another invasive from Asia. So the first thing they did was get rid of that. Then they planted 70 species of native plants, put in a water feature that they call a bubbler. And then they started to count the birds using their yard. And they're up to 149 bird species, including 35 warbler species. If there are any birders in here you know that's an incredible number. Cindy and I only recorded eight warbler species at our house. So, does it work on smaller properties? Absolutely.
What about urban yards? Let's go to Pam Karlson's house in Chicago. And I mean in Chicago; right on the other side of that wall is O'Hare Airport. She has 1/10 of an acre--that's three times smaller than the average lot size in North America. She's not connected to any natural area at all. So she is an island in the middle of Chicago. It's a pretty Island. Because Pam is a native plant landscaper and she knows how to do it. But she did the same thing the Terpstras did. She got rid of her non-native plants, put in 60 species of native plants, including a water feature, and then she sat back, and she says, with a glass of wine (I think it was more than one glass) and started to count the birds using her yard. She's up to 125 bird species that have used her yard so far. She sends me the numbers as they come in. And that includes a woodcock--so there's Pam's woodcock; if you haven't seen a Woodcock lately, go to Pam's house in Chicago.
All right; there's four things we need to think about if we're going to succeed in a big way, and we want to succeed in a big way. And that means we've got to talk about those big lawns. We've got 44 million acres of lawn in this country. That's an area bigger than all of New England combined, dedicated to an ecological deadscape. And we do that because it's a status symbol. It's a really ingrained status symbol. And because we have to display our Halloween decorations. But what if we cut that area of lawn in half? We're not going to get rid of it; we're just going to start cutting it in half. What if we take spaces like this and turn it into this? I got this picture from Dan Getman. And he's just starting. I've never met Dan, he lives in Missouri, but he said, "Look, I had big lawn and I'm putting the plants back." Okay, well, let's make the math simple. Let's say we've got 40 million acres of lawn; we're going to cut that in half. That gives us 20 million acres that we can restore right at home simply by removing some of the lawn. That'll give us enough space to create what we're calling Homegrown National Park, a new National Park. And it'll be big. It'd be bigger than the Adirondacks plus Yellowstone plus Yosemite plus Grand Tetons, Canyonlands, Mount Rainier, North Cascades, Badlands National Park, Olympic National Park, Sequoia National Park, plus the Grand Canyon, plus Denali, which is huge. Plus the Great Smoky Mountains. Add up all these parks; it's still less than 20 million acres. So Homegrown National Park will be the biggest park in the country.
What do we get when we put a park at home? You get the chance to interact with some part of the natural world. All you have to do is go outside, you can do it your own time, your own pace, maybe all you have to do is look out the window. You can avoid crowds. If you go to a real national park; last year, 375 million people were there with you. So I know what you're really going to interact with. It's free, there's no admission fee, it's never closed, no matter what pandemic comes down the pike or no matter how many times we close the government. You can avoid travel hassles, which to me is very important. And you get to experience the natural world alone. Alone is a really, really important component here. It's the only way you're going to develop that unique relationship with Mother Nature; just you and the life that's out there, not mediated by somebody else.
And this is particularly important for our poor kids, who are suffering from nature-deficit disorder, according to Richard Louv. So we're trying--we get 30 kids, we put them on a bus with the teacher and they drive for an hour, and they walk around a natural area; teacher tells them not to touch anything. Then they get back in the bus and they go home. And that's their experience with the natural world, which I'm sure is better than nothing. But it's really been an experience with 30 other kids and a teacher telling them not to touch anything.
If they have some part of nature right at home, all you have to do is go outside and get to know it, become familiar with it. Become comfortable with it. Fall in love with it. Alone, no parental supervision. When we hover over our kids, we're sending the message that this is dangerous stuff. You're not capable of doing this on your own. That's a terrible message to send to the future stewards of the planet. If they don't know what stewardship is, if they're afraid to be a good steward, if they don't love stewardship, they're going to be lousy stewards, and we can't afford any more lousy stewardship.
And maybe we're gonna learn how to hunt lizards. I'm learning this from my own granddaughter, Zoey, who lives in Hawaii on a very modest patch of nature. But she found, she discovered there are no lizards there. And when she discovered that, she sent me this picture to describe very seriously how you hunt lizards: you get on the ground and you cover yourself with leaves and sticks so the lizards can't see you coming. Then you crawl very slowly towards the lizard. No smiling; this is serious business. You can wear your best dress, that's okay, but you sneak up on the lizard, you catch the lizard, you put it in an aquarium, you learn how to take care of it. You learn how to be a good steward of that part of nature, you fall in love with that part of nature. Now, I don't think Zoey's always going to be crawling on the ground catching lizards in her best dress the rest of her life (I don't think). She sent me this picture not too long ago, so who knows. But I guarantee she's going to remember those interactions with nature of the rest of her life, and I guarantee they're going to help her be a good steward of the planet. And if you want to join Homegrown National Park, you can do it, it is a real thing now, and it's a real thing largely because of Michelle Alfandari, who's sitting right here. Wave to everybody, Michelle.
Doug Tallamy 41:18
We're a small nonprofit now, that is real. And the object is to get yourself, get your property registered on the map. So it's free. You don't have to pay anything but you record where where you live, your location, and the amount of land that you own that you're going to be a good steward of. Maybe you really are going to reduce the area of lawn, maybe you're going to plant an oak tree, maybe you're going to put an aster in a flowerpot; doesn't matter the size of the area you're being a good steward of, but you record that in the database, and then your little piece of your county is going to light up and you get to see who else in your county has joined Homegrown National Park.
And the object, of course, is to get the message that everybody's responsible for good Earth stewardship to go viral. We want the entire country to light up. What are we asking? We really are asking people to reduce the area of lawn. There are important ecological goals that every property has and lawn doesn't accomplish any of them. And we want to replace some of that lawn with the native plants that do accomplish those goals. We want to remove invasive species; most people have invasives on their property and they don't even know it. And if you're protecting any natural area, and I look at the properties around here, a lot of you are protecting very important natural areas, you want to keep doing that.
There are important ecological products associated with Homegrown National Park. Significant increase in biodiversity is one of them, and just look at what's happened at our house in Oxford, Pennsylvania. It works because nature's really resilient. If you give nature a helping hand, it will restore itself. Measurable reduction in invasive species: if everybody got rid of the invasive just on their property--remember, 78% of the country is privately owned--we'd be 78% done, 85% done east of the Mississippi. Significant drawdown of atmospheric CO2: lawn is the very worst plant choice for capturing carbon. So if you replace it with any other plant, and that's a very good example right there, you're going to sequester a lot of carbon, much of it in the soil. And, of course, you're building viable habitat. Any bit of habitat that we build outside of parks and preserves is going to help conservation inside of parks and preserves.
But there are also important sociological products associated with Homegrown National Park, and national awareness is one of them, not just of what the problems are, but what the solutions are, and our roles in those solutions. We really are trying to change the culture; we want people to recognize that nature is not optional. It's not just there for our entertainment. It's essential, it's essential for everybody, which means everybody shares the responsibility of sustaining it. We want to convert hope into action. Hope is good, but action is better. And we want to merge existing conservation organizations onto one visual--the map, so things like Audubon and National Wildlife Federation and Wild Ones and all the land conservancies. They're all doing wonderful conservation on private property, but nobody's recording it in a central place. That would be what the map is going to do. Remember, we've got the 30 by 30 Initiative, we're going to save 30% of the country by 2030. That's a U.N. initiative. People say it's Biden's initiative; it's not, it's a U.N. initiative. It's not going to happen unless we record conservation on private property.
So we're going to shrink the lawn and we're going to join Homegrown National Park. What plants should we put in the spaces that we remove lawn from? I'm going to argue that some of them have to be what I'm calling keystone plants. Remember what a keystone is. It's a stone in the middle of the Roman arch. And if you take that stone out of the arch, the arch collapses. Well, if you take keystone plants out of your local food web, the food web collapses because they are making most of the food. Just 14% of our native plants, the keystone plants, are making 90% of the caterpillar food that drives those food webs. So think of the keystone plants and the ecological house that you're building as the two by fours that hold that house up. They are the support system; you're not going to have an ecological house without them. We've been trying to build houses with wallpaper for the last 100 years, and that's that's just not going to work.
So what is the best keystone plant around the country? I've already mentioned, it's one of the oaks in the mid-Atlantic states that support 557 species of caterpillars. And just to compare that to a good tree like a tulip tree, tulip poplar. So it's a wonderful native plant, but it only supports 21 caterpillars. So there's huge differences among our native plants. And that's why we've separated out the top ones. They support 950 species of caterpillars nationwide. So there's no other plant genus that comes close to that. How do you know what the best plants are where you live? You go to Native Plant Finder in the National Wildlife Federation website, put in your zip code, and the ranked list of the most important woody and herbaceous plants will pop up for your county. This is an abbreviated list, because I ran out of room. So the old excuse of, we don't know what to plant; that's just an excuse now. We do know what to plant, so let's plant.
All right, so we're going to shrink the lawn, we're going to put in keystone plants, we're going to invite a lot of insects to our yard, and then we're going to kill them with our security light. Which of course is not the goal. It turns out that light pollution is one of the major causes of insect declines. Not just in this country, but throughout Europe and other parts of the world. And these are all the ways that lights are killing insects, particularly the moths that make those caterpillars that run our food webs. It seems like a disaster, but it's actually good news to me. Because we have got to stop. We've got to turn around insect declines; we've already lost more than 45% of the insects on the planet. Not only do we have to stop doing that, we've got to rebuild those populations. And if we can do that by flicking a switch, we're getting off easy. There are a lot of switches to flick. But there's a lot of us to be switch flickers. But you know I hear all the time, "well gee, I can't turn the light out over my barn or over my garage or over my front porch because the bad man will come." All right, put a motion sensor on your security light so it only turns on when the bad bad does come. And the first thing you'll realize that the bad man doesn't come very often. Even easier is to take the white bulb out of your security light and put in a yellow bulb. Yellow LED, yellow incandescent, because yellow wavelengths do not attract nocturnal insects. Very few nocturnal insects go to yellow wavelengths. If we switched out our white bulbs for yellow bulbs, overnight we would save millions of insects, and if we use LEDs, it'd be millions of dollars as well.
So we're going to shrink the lawn, we're going to use keystone plants, we're going to modify our light system, then we're going to invite one of the mosquito foggers to come kill all of our insects. It's a booming business around the country. So it's not appropriate everywhere but people are doing it everywhere. They say it's okay because what they're fogging is a natural product and it is a natural product, it's pyrethroids. That's the compound made by chrysanthemums that kills insects. It's industrial-strength pyrethroids, but they say it's natural, so it's okay. Well, cyanide is natural, ricin is natural. There's a lot of things that nature makes and not such good, good things, even though they're natural. They also say it only kills mosquitoes. And I wish that was right. But it kills all the insects that it comes in contact with, which is all the insects, including our beloved monarch. You know the monarch's red-listed now; we've lost about 96% of them. And this is a result of a mosquito fogging event in the eastern shore of Maryland. It's happening all over the country. What is interesting to me, or ironic, is that it doesn't control mosquitoes. We're doing this for nothing. Actually, it's expensive.
Doug Tallamy 49:08
It doesn't control mosquitoes because you don't control mosquitoes in the adult stage. It's too hard. You've got to kill 90% of them to get good control; these guys killed between 10 and 50%. So they have to keep coming back and back and back. If you really want to control mosquitoes, you do it in the larval stage. And using mosquito dunks, bacillus thuringiensis; biological control is a very good approach. Get a bucket, fill it full of water, put in a handful of straw or hay or maybe some dead leaves, put it out in the sun so it can build up populations of diatoms and algae, and that is what mosquito larvae eat. So what you're doing is creating an irresistible brew for the female mosquitoes in your yard that want to lay their eggs; they will preferentially lay their eggs in your bucket. Then you go to the hardware store and you get a sheet of mosquito dunks, $12 for a whole season's worth of control. Put in a dunk; again, that's bacillus thuringiensis, a natural bacterium that only kills aquatic diptera. And the only aquatic diptera in your bucket is mosquito larva.
If a dragonfly gets in there won't hurt it a bit. If your dog drinks it, no problem. You might put a core screen over it so the chipmunk doesn't jump in. But it's targeted, it's cheap, it works, particularly if everybody did it. And I will admit, I mean, we've been walking around here, you've got a lot of water around, you got a lot of places for mosquitoes to breed so and the farther north you go, the more mosquitoes there are, it's part of the local ecosystems. So some places you just have to accept that. But if you want to kill mosquitoes, this is the way to go. Don't kill everything else. You know, this works too: get a fan, plug it in, and put it on your back porch and sit in the breeze; the mosquitoes do not fly into the directed breeze, you don't have to kill anything.
All right, the fourth thing that we need to do is to landscape, particularly underneath our trees, in a way that allows those all-important caterpillars to complete their development. What do I mean by that? Well, this is just an example. I live in in Chester County, Pennsylvania, where oaks support 511 species of caterpillars. A few of them, like the polyphemous moth, complete the development on the tree, the caterpillar eats the leaves, then it spins a cocoon and hangs from one of the branches, then it emerges as an adult, then it does it all over again. Everything happens on the tree. But that's not true for most species. Most species will finish growing as caterpillars on the tree and then drop from the tree and wiggle their way underneath the ground and pupate underground. Or they spin a cocoon in the leaf litter that's under the tree. And that's the problem. There is no leaf litter under the tree. We don't tolerate it. It's messy. And we mow and compact the area around the tree so it's rock hard, particularly in the summertime. Very difficult for those caterpillars to get underground and pupate successfully. And I am convinced that this is another major cause of insect declines around the country.
Of course, the cement landscape is not the answer either. This is what most people do. You got a tree in the yard and I've got a new grad student, Emma Jonas, this year, who is measuring how well caterpillars do a situation like that. But I guarantee they're going to do better in a layered landscape like this, where you have a tree, maybe a dogwood here and then native azalea, and ferns, and ground cover. It's soft landing. The caterpillars drop down, the ground is not compacted, nobody's gonna mow them, nobody's gonna step on them. You can easily get much more survivorship in a situation like that.
This is where you can do your fancy spring ephemeral gardening. Put beds around your trees. This is how you shrink the lawn, folks. It's big beds around your trees; the bigger, the better, and all of a sudden you have less lawn. The trees will love it and so will those caterpillars. Use your native ground covers liberally; things like wild ginger, native pachysandra, there's Virginia creeper as a ground cover, golden seal, mayapples, foam flower, ferns. If you can see the ground, you don't have enough plants. Green mulch is the way to go. Again, your trees will love it. And so will those caterpillars.
Former grad student Desiree Narango did some wonderful work with chickadees in the suburbs of Washington D.C. And her work actually suggests there's room for compromise in our plant choices. And that's good news. She had one simple question: How well do suburban yards that are dominated by native plants support chickadee populations versus suburban yards dominated by traditional ornamentals, introduced ornamentals? And when they're dominated by introduced ornamentals, they support 75% fewer caterpillars. So right away, you reduce the amount of bird food by 75%. They were 60% less likely to have breeding chickadees at all. So every every yard had a nest box up in it, but the chickadees would come and say there's not enough food here, we're not even going to try to breed. If they did try to breed, they laid 1.5 fewer eggs, those clutches were 29% less likely to survive. If they did survive, they produced 1.2 fewer fledglings, and it took them 1.5 days longer to do that.
And if you put all that into a population growth model, as a function of the percentage of non-native woody plant biomass, from none to 100% in your yard, this is what you get. We looked at woody plants, because that's where chickadees forage on, woody plants. The dotted line there is replacement rate. That is the rate at which the population has to make babies to replace the adults that die every year. Chickadees don't live that long. And if you're reproducing at that rate, you have a sustainable population. It's not growing, but it's not shrinking either. If you make more babies, and adults die, anything above the dotted line there, you've got a growing population. But if you have fewer babies, and adults die, which is what you have when you have a lot of non-native plant biomass, you've got a shrinking, unsustainable population. Right here is where those lines very liberally intersect, which suggests you can have up to 30% of your woody plant biomass non-native without destroying the local food web. Now we can't tolerate any invasives; nope, no barberry, no burning bush. They are ecological tumors. They escape and castrate our local ecosystems. But there are a lot of ornamental plants that are not invasive.
Remember Dan Getman, that's a gingko tree. Did you pick that up the first time? Why does Dan have a gingko in his native plant garden here? Well, Dan's wife likes ginkos. And she said, Give me a gingko, Dan. And he did. The question is, is that tree wrecking the productivity of this landscape? No, it's just there. Is it going to escape and wreck the woodlot as an invasive species? No. It's just there. So what's a plant that's just there? I think of them as if they're statues. So there you go. There's Dan statue. Now, if every plant in Dan's landscape was a statue, it wouldn't be a functional landscape. But it's not the presence of non-native plants that destroys local food webs. It's the absence of those productive native plants. So if we increase the number of those, we can tolerate many of these.
Can we use native plants in formal landscapes? Of course we can. This is a Lynn O'Shaughnessy design taken from a drone 400 feet up; you do not get more formal than that. And every plant in that landscape is a native plant. Formality is a function of the design, it's not a function of the plants in the design. Our native plants are used in formal designs in Europe every day and they love them over there. If they can love our native plants in formal designs, so can, so can we. Can we get a pollinator garden into a suburban yard like this without offending anybody? Of course we can. Just put a little fence around it. It formalizes it, it tells your neighbor it's not a bunch of weeds you forgot to mow. It's pretty when it's in bloom, it's meeting the needs of several species of bees. It's not very big; could be bigger, but if everybody did it, it would help.
Help what? Help make pollinators. Why do we need pollinators? Well, the media will say we need him because they pollinate a third of our crops. It's about about a 12th of our crops. And I hear people say, "Well, I don't live next to a farm so I don't need any pollinators." Forget the crop argument. We need pollinators because they're pollinating 80% of all plants, and 90% of all flowering plants. And we need pollinators everywhere we need plants, which is everywhere. How about this? Drew Lathin design, much bigger. Imagine the amount of life here versus the amount of life here; seems like a no-brainer.
Can municipalities help us live with nature? Yes, they can. More and more they've been doing it. Minnesota been doing it for several years now. They've got a cost sharing program that the state is paying homeowners to reduce or replace their lawn with appropriate Minnesota prairie plants. It's very popular. Pennsylvania started a new program like this. That's popular too. It's not funded very well, so it's a big long waiting list, but. There's an island off of Florida, I think it's Marco Island, that is paying homeowners to allow burrowing owls, listed species, to burrow in the front yard. This is the way the Endangered Species Act should have been written, with carrots rather than sticks. If you have an endangered species on your property, we're going to pay you to take care of it, rather than fine you if you use your property. Everybody would want an endangered species. Put a bounty on the invasives that we're selling, like Callery pear. That's what St. Louis, Missouri did, Fayetteville, Arkansas, North Carolina. Take out a Callery pear, you get a free tree replacement. Utilities are giving people $100 coupons to plant water-efficient native plants. And, of course, the big lawn reduction programs, particularly in California; that's gone up: $3 per square foot rebate for every square foot of lawn you transfer, you replace with a xeric planting. Of course, California doesn't have one drop of water to waste on lawn. And if you want more information on all of those programs, memorize that.
Doug Tallamy 58:45
All right, I think we've made three missteps in the early years of conservation. And the first one is important. We're starting to think of nature as if it's optional. We like nature. We like to walk in it and we like to birdwatch, ride our bikes, but it's not essential. And if it's not essential, when push comes to shove, when resources are in short supply--which is always--nature takes a backseat. I went to the Cincinnati Zoo, and there's this wall-size poster there, which to me epitomizes our society's view of conservation. We want to save nature, we want to save wildlife so that future generations can enjoy it. That was Teddy Roosevelt's argument for expanding the national park system. Gorgeous places; we want to save them so that future generations can enjoy it. And I get that, because nature is enormously entertaining.
But it is much more than that. We need to save nature so that we have future generations; it's a little bit more urgent. We've also assumed that humans and nature cannot coexist. And we talked about that. But if we confine conservation just to the places where there's not a lot of humans, we're going to fail because those places are too few, too small, and too isolated. David Quammen has a wonderful analogy between a Persian rug and an ecosystem. That is a functional Persian rug. That's not 71 Persian rugs; that is 71 rug fragments, none of which are acting like a Persian rug. And that's what we've done to our ecosystems. The U.N. designates biosphere reserves as places of ecological significance. And I don't like that language because it suggests there's places without ecological significance. Not so--every square inch of the planet has ecological significance, including our yards, including our corporate landscapes, including our roadsides, even including much of our agriculture. So we need to glue our rug back together again, folks, we got to put the plants back, not just to create biological corridors that allow plants and animals to move back and forth between viable habitats, but to recreate viable habitats in all those places where we've destroyed them. It's starting to happen, it is really starting to happen. And when it does, it'll be the first time in modern history that we humans actually have coexisted with the natural world.
Our third misstep was to leave Earth stewardship to just a few specialists, a few conservation biologists, a few ecologists. For some reason we didn't see it as an inherent responsibility of everybody on the planet. But I don't know why, since every single person on the planet depends entirely on the quality of local ecosystems. So why wouldn't they all share the responsibility of taking care of those ecosystems? Stan Rushworth, the Cherokee elder, once said, "The Western settler mindset was, 'I have rights'. The mindset of Indigenous people is, 'I have obligations'". You're not born with those mindsets; you're taught them. We're very good at teaching this one. We have been terrible at teaching our kids and our peers that we all have obligations to good Earth stewardship. That does not mean you have to save biodiversity for a living. But you can save it where you live. And if you do, it empowers you. More and more of us are recognizing, the Earth has some serious issues. But most people feel powerless. What can one person do?
Well, one person can shrink the lawn, one person can modify their lights, one person can put in a pollinator garden, one person can remove invasive species, one person can fire Mosquito Joe, one person can modify their lights. I say that; one person could do all the things we just talked about and revitalize the ecosystem right in their property, and then enhance their local ecosystem instead of continuing to degrade it. And it also shrinks the problem; then it is something that's manageable for each one of us. Don't think about the entire planet's problems, you'll get depressed; just worry about that piece of the planet that you can influence. If you own property, it's obvious. That's where you start. If you don't own property, help somebody who does: help a land conservancy, help a park or preserve; they're all underfunded, they're all under staffed, they will love you as a volunteer. So as a property owner or a volunteer, each one of us has the responsibility--we certainly have the power--to fix dead landscapes like this. Whether or not we do so is going to determine nature's fate, and then ultimately our own. So I think I've convinced my grandchildren that you are nature's best hope. I hope I've convinced you as well. Thanks very much.
Joshua Ginsberg 1:03:20
So I like mathematical equations, and we're 10 minutes past eight, which is 10 minutes later than we thought we'd stop. But I don't think I would take one minute away from any part of that lecture. There are books outside that Doug will sign. And there's dinner to be had for all of us. But I have a reservation for Doug and need to feed him because he's staying for his supper. So I'm going to do something that will be very hard, which is take two questions from the audience and two questions from online. And then we will let Doug go upstairs. Please do not rush the stage, there's no mosh pit, go ahead, if you want to talk to Doug, buy a book; he'll sign it and you can talk to him while he's signing. So, hand up there because it was the first hand up. Yes.
Unknown Speaker 1:04:13
[inaudible]
Joshua Ginsberg 1:04:16
Phrased as a question please, quickly.
Speaker 3 1:04:20
Some of what you talked about, we have to worry about some of what we plant, we have to worry about ticks.
Joshua Ginsberg 1:04:29
Right. So can you address the tick problem.
Doug Tallamy 1:04:31
Tick problem, right? Of course. This is what Cary Institute does. They look at the association between ticks, white-footed mice, acorns, and deer. Ultimately, we've got a Lyme disease problem because we've got too many deer. Now I know you're not going to solve that immediately. But there are products you can use. There are fewer ticks in lawn than in the woods, which is why one of the reasons I suggest we don't get rid of lawn; we have swaths of places where we're going to walk. Be vigilant during the really infective periods, which is May, June would be the height. You can get it at any time, but those are the times you really want to be vigilant. But you know, the solution of, "I'm going to get rid of all plants, so they don't have any ticks," you know, then we're getting rid of the whole planet. So we have to find a compromise. And ultimately, we've got to control those deer, because that's why we have the explosion of the black-footed tick.
Joshua Ginsberg 1:05:28
Distributions, in many ways. All the way at the back.
Unknown Speaker 1:05:33
[inaudible]
Speaker 4 1:05:35
I have two questions. Is there a resource that we can access that will [inaudible] ... that are very good in certain spaces, like native plants or other things? And the second question is, is there a possible way for homeowner or a landowner to bring in insects and wildlife? Is that possible?
Doug Tallamy 1:05:56
Okay, first question, go to our website, homegrownnationalpark.org; there's lots of resources there that will direct you to plant availability, know-hows, all the things that you need to know.
Can you introduce insects to your yard? You know, insects are really good at finding the plants that they need. So the best way to bring them in is to plant the plants that support those insects. And I'll point to, again, my yard in Pennsylvania is a great example. It was bare dirt over much of it, and we put plants back and now we've got thousands, literally thousands, of species of insects and all those things that have come in and found those plants. So yes, you can bring insects in, but it's easier to bring the plants that support them,
Joshua Ginsberg 1:06:36
Like teenagers. They're hungry; they'll come to food. Lori.
Cary Institute 1:06:41
So I'm gonna take a few questions from the online audience. Jennifer from Falls Church, Virginia asks, "With climate change and hardiness zones migrating north, how important is it to stick with plants historically native to a particular ecoregion?"
Doug Tallamy 1:06:56
Yes, you're asking about assisted migration. Should we be moving plants up from the south because the planet is getting getting warmer? I'm not a fan of that. It's controversial. Some people want to do that. But you know, it's not a gradual warming of the planet, it's an increase in climate variability; we still get the cold snaps, we get climate going like this, and moving plants up from the south that are not adapted to those wild changes, is not going to going to work out very well.
And of course, the reason we do want plants to be able to survive here, but you also want them to support the nature that we're talking about. And if you move plants from an ecosystem, you know, away from that ecosystem in which they co-evolved with all the creatures they support and put them in another one where they don't have those relationships, then it's not going to be a very productive plant. And we've actually shown that that is true with oak trees. If you plant an oak outside of its range, it doesn't support anything. So you want to stay within the natural range of that plant and hope that it's got the genetic variability that it'll be able to adapt to the wild changes that we're throwing at it.
Cary Institute 1:08:00
And then these are two brief questions on the same theme. Amy from Baltimore asks, "If you live in an apartment with a terrace for potted plants, what's the best thing you can do to help the environment?" And Jay from Flushing, New York asks, "In the New York City urban setting, do you have thoughts or suggestions about tree pit plantings and container planting?"
Doug Tallamy 1:08:19
Yeah, we got a new cryptogamic container plantings. Eighty-two percent of us live in cities. So turning that pile of bricks that we call an apartment building into a resource, particularly for pollinators and migrating monarchs, is important. You can do that on your patio or on your balcony with container planting. And we have a new resource on the Homegrown National Park website called container planting, where you can find out the best plants in your ecoregion for container plants, the best native plants, anywhere in the country. And when we launched that, it got a million hits. So it's very, very popular. So, 7 million!
Joshua Ginsberg 1:08:56
Seven million. Okay, so can we thank Doug one more time?
