Taking A Walk On New York's Wild Side

Apr 6, 2012
Originally published on April 6, 2012 12:03 pm


This is SCIENCE FRIDAY. I'm Ira Flatow, coming to you from the American Museum of Natural History in New York, and this museum sits right on the edge of Central Park. If you're here in the audience, you'll know that Central Park is right next door, where New Yorkers and at this time of the year a lot of tourists come to sit in the shade of its trees, they walk among the wildflowers, the birds.

And they think that this is probably the only refuge for wildlife on this island of Manhattan. Well, if you walk around the city and you keep your eyes open, and you know what do look for, you will see that this concrete jungle is really more jungle than you think.

It's teeming with plant and animal life, not only in Central Park and Prospect Park, among others, but also wildlife abounds in former industrial sights and even the street medians, right there in the middle of the street. Some city locales attract nature lovers from all over the world.

As you know, Central Park is also a birding hotspot. New York Harbor is a seal-watcher's paradise. Did you know that? Have you been out to watch the seals in New York Harbor? And Flora Lichtman is going to come by later and talk to us about how you can watch coyotes romping in the Bronx. If you know where to look, you can see them there.

And amazingly, researchers continue to find new critters living right here in the city, like they just found the Gotham bee or a species of leopard frog. Did you read about that? They found a new species of frog on Staten Island, and many of these things have been right here under our noses all the time, we just haven't seen them or know where to look for them.

So the Big Apple tells us a familiar story of metropolitan areas which have rich pockets of biodiversity but also, of course, because it is an urban area, it's under threat from rapid urbanization, and it raises all sorts of questions, like how does the waste treatment plant we built affect the fish that live in the urban waters?

Or if we build a little dam someplace as part of the city, how is that going to affect the other wildlife? How well does the ornamental plant we grow in our gardens support other vegetation in the area? And ultimately, how does a loss of urban biodiversity, how does that affect all of us who live in this city?

So that's what we're going to be talking about this hour, and if you're here in the audience, as I said before, please feel free to come up to the microphone and ask your questions, and we'll be accepting Twitter and tweets all week on SCIENCE FRIDAY. Let me introduce my guests.

Dr. Eleanor Sterling is director of Center for Biodiversity and Conservation at the American Museum of Natural History. Welcome to SCIENCE FRIDAY.

ELEANOR STERLING: Thank you so much.

FLATOW: Thank you. Sarah Aucoin is director of the Urban Park Rangers with the City of New York Parks and Recreation. Thank you, Sarah, for being with us today.

SARAH AUCOIN: Thank you.

FLATOW: Dr. Jason Munshi-South is assistant professor of biology at Baruch College and the Graduate Center here at the City University of New York. Is that there on 34th Street?


FLATOW: Yeah, a lot of good - a good library there too. And also with us is Dr. Merry Camhi, she's director of the New York Seascape program at the Wildlife Conservation Society based at the New York Aquarium. I want to welcome all of you to SCIENCE FRIDAY. And yeah, you can applaud.


FLATOW: Let me ask Dr. Sterling: Is New York City a good place to study, teeming with biodiversity?

STERLING: Absolutely. I mean, you just mentioned a new species. That's something that scientists are very excited about. It's fun to find a new species.

FLATOW: How do you find that? How is that found, the frog?

STERLING: You know, the species that you didn't mention, which is even more fun, is right across the street in Central Park. So here at the Museum of Natural History, we wanted to work with the Park Service to understand about how do you maintain the park, how do you understand how leaf litter fauna, the organisms that live within the soil, help to recycle nutrients to be able to grow those beautiful trees and plants we see over there.

Well, in the process of doing some research into what soil fauna is found over there, we found a new species, in fact a new genus, of centipede. It's a dwarf centipede, and it comes from Central Park.

FLATOW: You mean this could be the kind of thing people have been stepping on all their lives?

STERLING: Pretty much, yeah.


FLATOW: How do you discover something like that? Is it just by accident, you don't go looking for centipedes?

STERLING: No, you go looking for what's in the soil, and you collect a lot of different things, and you send it out to the experts of the world, who then are able to compare what they find with what they already know. And then eureka, they find something that they've never seen before, and they give it a new name, like Gotham bees. Isn't that a great name? That work came out of the Museum of Natural History as well. Gotham bee. That's the fun...

FLATOW: Is that its official name?

STERLING: Its official name. It's got a scientific name as well, but it's got Gotham in it, the scientific name as well.

FLATOW: Wow. Sarah Aucoin, you are the director of the Urban Park Rangers. Urban Park Rangers are constantly fielding questions, right? People are asking them about the wildlife. What do you - what's the most surprising thing that they don't know about New York City wildlife?

AUCOIN: I think people tend to think that a city and nature are antithetical to one another, that there's a separation. And when they - one of the things that Urban Park Rangers are focused on is connecting New Yorkers to the nature that's right here in New York City.

So really any opportunity to showcase biodiversity, whether or not it's in Central Park or in a schoolyard, just looking at a street tree in the street tree pit, that can be a very surprising experience for many New Yorkers. And it's that sort of a-ha moment, when someone understands that there's nature in the city and that it's a part of their lives, and they have an impact on it and make a connection to it, that you can really draw them in and then begin to explain all of the other wonderful things that are here.

FLATOW: Dr. Aucoin, I understand that there is Zelda, a wild turkey, living...

AUCOIN: Yes, and there are a lot of great stories about wildlife in New York.


FLATOW: Tell us about Zelda. Where does Zelda...

AUCOIN: Zelda lives in Battery Park, and you know, we talk about her all the time, but we get a lot of questions about her around Thanksgiving.


FLATOW: She's safe for Thanksgiving.

AUCOIN: She's safe, and she's, you know, she's someone that - she's an animal that many people have made a connection to as well, which I'm going to come back to again and again because when people see her, they're surprised to see that she's there. She's in a very unusual environment. But she's just an example of all of the wonderful diversity that you can find here.

Zelda does actually leave every year. We think that she's going off to try and find a mate. And she returns, and she lays eggs. They haven't been viable yet. She's - you know, she acts like a wild animal, even though she's living in a park, that(ph) wouldn't be a natural habitat for her.

FLATOW: So there's another turkey somewhere, she's laying eggs.

AUCOIN: Well, no, she's laying eggs, but they're not fertile.

FLATOW: They're not fertile eggs.

AUCOIN: No, but there are lots of turkey in New York City. In the Bronx, in Staten Island, we have big turkey populations.

FLATOW: Is that right?

AUCOIN: Yes, and you know, so there's a lot of exciting stories. There's beaver in the Bronx. The population of beaver just actually doubled last year, which means we have two.


AUCOIN: You know, there are flying squirrels in Queens, living in Forest Park in Queens. About 10 years we undertook a survey of parks with a professor from Fordham University, and we discovered that there were flying squirrels in Forest Park, that there were coyote in the Bronx. So there's a lot of surprising stories.

But again, that's just an entry point to connect people to the diversity that they're going to be able to see right outside their door.

FLATOW: Dr. Munshi-South is a professor of biology at City University. You do a lot of research into the city parks, and you know that in the biodiversity, as Sarah was saying, there's more than just pigeons and rats and bedbugs and things like that, right?

MUNSHI-SOUTH: Right, there's actually a subset of native species that were here before New York City was present. And you can still find quite a number of them running around the parks. You won't necessarily see all of them. You might need to set out traps or cameras or something like that.

But we're mostly focused on working on small mammals and stream salamanders as models for urban biology.

FLATOW: And what kind of strange stories can you tell us about maybe the stream salamanders or urban biology, that people are surprised to know about New York City?

MUNSHI-SOUTH: Right, what was really striking to us is that we started studying these populations of mice and stream salamanders in several parks. And we thought they'd form sort of a big population in the city and they'd be able to move between parks and spread their genes and so forth.

But we actually went out and we trapped mice and salamanders at a bunch of different parks, and we looked at various DNA sequences around their genome, and we found that actually each park has a fairly distinct population of mouse or salamander, even to the point where if one of you found a dead mouse or a salamander in the park and brought it to us, we could, you know, spend a couple weeks in the lab, and we could probably tell you which park it came from. We just weren't...

FLATOW: Is that right?

MUNSHI-SOUTH: Yeah, we were really surprised at the level of genetic differentiation that was already building up...

FLATOW: So it's evolving in its own little environment there? Is evolution going on in...

MUNSHI-SOUTH: That's right. So the simplest definition of evolution is just the change in different forms of genes over time. And one of the main mechanisms through which that happens is called genetic drift, and that's just random changes in DNA that build over time. And what's happening in these parks is that the animals are stuck in there, they can't really move around through the city and spread the genes. So generation after generation, as they're breeding, these mutations are building up, and the populations are changing from each other.

So that kind of genetic drift is definitely happening, and it's a fairly potent force in - at least for small mammals and salamanders in city parks, because they're kind of stuck in these little islands of forest or a single stream in a park, things like that.

FLATOW: Now, Dr. Camhi, you study the waters around New York.

MERRY CAMHI: That's correct.

FLATOW: They're teeming with biodiversity?

CAMHI: They absolutely are.

FLATOW: Give us an idea.

CAMHI: OK, so, you know, we think of urban waters, I think we, especially here in New York, think of polluted waters, waters without life, and to a certain extent these - our waters really have suffered tremendously over the last three centuries of development here.

But I work for an organization, WCS, that does conservation all around the world, and we know - we work in 60 countries where there's very pristine wildlife, wild populations of animals. And when I started working for them, the question was: Why would we work in a place like New York City? Why would you work in one of the most urbanized ecosystems - marine ecosystems in the world?

And as it turns out, if you were to take a boat out, or swim five, 10 miles out from the Battery, you would see virtually - you would see very few signs of the urbanization that we see right here. It would look - almost looks like a blank blue canvas, and yet if you were able to peel away those waters and peer underneath the surface, the biodiversity in our waters is quite phenomenal.

We have hundreds of species of marine fishes. Many of the animals - I'm so thrilled to be in this room because we have this animal, the largest mammal...

FLATOW: Under the whale.

CAMHI: ...the blue whale - has ever lived on the planet, comes into New York, our New York waters, a 26...

FLATOW: Is that right, you can go see a blue whale?

CAMHI: Yes, blue whales have been heard singing, you know, not right here in the harbor, but 60 miles offshore. We have sharks. We have sea turtles, all - many of these animals are quite endangered, and yet the iconic mega-fauna really is still right here. And that gives us something to work on, something to help protect, because while the species are still here, populations have been very seriously depleted.

FLATOW: And most people don't realize this.

CAMHI: Most people do not have a clue. As a matter of fact, I spent my whole life growing up on one side of the Hudson or the other, and it wasn't until I actually started working on this stuff that I realized how phenomenal our biodiversity in our waters are.

FLATOW: We're going to take a short break, and when we come back, we're going to talk lots more about urban biodiversity here in New York City. And we invite you in the audience to step up to the microphones and ask your questions, because this is the one chance in a lifetime you might get to talk about it and learn about the different biodiversity.

Talking with Eleanor Sterling, Sarah Aucoin, Jason Munshi-South and - excuse me - Merry Camhi. So stay with us. We'll be right back after this break. Don't go away.


FLATOW: This is SCIENCE FRIDAY. I'm Ira Flatow. We're talking this hour from the American Museum of Natural History here in New York under the big blue whale, a good spot to talk about biodiversity in New York City and learning that the big blue whales swim right off the coast here of New York City.

Sarah Aucoin, why do we see so much bird diversity in New York? And we're a great bird-watching city, aren't we?

AUCOIN: We're an excellent bird-watching city. Some of the birding hot spots in the country, maybe even in the world, are right here in Manhattan and in New York City. So it's an excellent place. Fall migration is a wonderful time to see raptors from Belvedere Castle in Central Park. But spring migration, as well, in all of our parks is a really...

FLATOW: So we're a migration route, or do they - are they living here?

AUCOIN: No, we're on a migration route, and that helps to make this a great birding hotspot. But we also have raptors nesting here, you know, year-round. So we have birds that are here, as well, all year round. Right now, we think there are about 30 nesting pairs of red-tailed hawks in New York City. And, you know, you can see a red-tail hawk pretty much anywhere you are.

You don't have to be in a park. You could be on the Grand Central Parkway. I always say just look up, and you'll see one within the next 10 minutes. So, you know, it's an excellent place for watching birds.

FLATOW: Let's go to the audience, yes, ma'am.

BRITTA RILEY: Hi, my name is Britta Riley, and I work on a project called Window Farms, and one of the things that we're working on is urban agriculture. And I'm using the microclimate of people's windows to grow plants. So one of the things that we're working on is reviving agricultural biodiversity by finding species and varietals that have been, maybe, ignored in industrial agriculture.

And I'm wondering: Who in the scientific community, in academia, is working on this area of, kind of, taking advantage of some of the opportunities that we have in the city to bring in new species without creating problems of invasive species.

FLATOW: Yeah, you don't want those invasive species coming in. Eleanor, can you answer that?

STERLING: Yeah, I can answer that, in part, because we're designing some exciting moments in food for you, coming up soon, at the Museum of Natural History.

FLATOW: Moments in food?

STERLING: So there are a number of people who are looking at these issues. There are people who are looking at, not just window farming, but also whole buildings that are essentially vertical farms, and there's a group of people up at Columbia working on that.

There's an urban design laboratory that's looking at how do you feed a city and the energy resources that go into designing food and bringing food to the cities. My sense is that they're not actually looking at specific varietals or different organisms as happen often in some of the more agronomy organizations, like Cornell.

I'm sure they're doing great work up at Cornell because they're thinking, all the time, about how can we do a better job of reviving some of the heritage foods that we've lost track of here in the United States. And so, lots of interesting work happening.

And I don't know of anybody here in the city, but that would be because I don't know it, and it's probably happening somewhere.

FLATOW: Thank you very much. Question for you, Dr. Munshi-South. We as New Yorkers have to put up with the stresses, the noise, the urban pressures. How do the animals do that? Do they adjust? Can they adjust to it - all that kind of stress?

MUNSHI-SOUTH: Right, that's a good question, and some of our work has shown that the parks are full of a myriad of stresses. One of the things that often happens to native wildlife that do well in the city, is that they exist at much higher population densities than they do outside the city. A lot of their competitors have gone extinct; their predators are not here anymore.

So one thing they're dealing with is just living in these very dense, crowded populations where the competition for resources, for a mate, for breeding opportunities, is very intense. So there's all those kinds of stresses. That can lead to higher disease loads, parasite loads, things like that.

We've also been working with a group of high school students at the High School for Environmental Studies who have been going around to the parks and other green areas in the city and sampling the soil. And they found that there is fairly high heavy metal concentrations, like of lead and chromium and nickel, and that sort of thing in these parks.

It's not unsafe for people to go there and so forth, but if you're a small mammal running around in the park, and you're eating seeds that have been produced by plants there, growing on these soils and so forth, you have these heavy metals building up in the body.

One project we've been doing recently is sequencing the genes of mice living in the parks, and so far we've sequenced about 18,000 of these genes. And we're looking for genes that encode for proteins that are changing in the city. So they're changing through natural selection. There are changes in the protein that are allowing the mice to survive better or reproduce better, long-term.

And what we have found is that some of these genes that are changing have to do with heavy metal detoxification. They have to do with metabolism, so how mice use energy.

FLATOW: So they're adjusting to the stresses, to better deal with the stresses through the changes in their genes. Wow, they're evolving quickly.

MUNSHI-SOUTH: That's right. Even, you know, over a time period of just 100 years, which from the perspective of a mouse might be 300 or 400 generations, we're starting to see these adaptive changes in some of the proteins in mice that allow them to deal with stressful urban environments.

FLATOW: I'm not going to ask about the rats, them adjust. Are they adjusting? Just, no one studies the rats.

MUNSHI-SOUTH: Right, so, you know, I get asked all the time: When are we going to start studying subway rats? And rats are disgusting, right?


MUNSHI-SOUTH: I'm slowly being, you know, beaten down. I think we'll have to start a study soon. But one thing that we know that's going on with rats and mice in the city, so the mice we deal with in the parks are native species, called the white-footed mouse. But then we have the house mouse and the Norway rat, which were brought here from overseas, right, and they live with us, and they're a pest.

One of the major poisons that we use against rats and mice is Warfarin, which is this blood anti-coagulant, and it turns out that they've actually been evolving resistance to that poison over the years in New York City and around the world.

So they're under very intense selective pressure because we're constantly trying to kill them, to exclude them and so forth. So they're an excellent kind of example of rapid evolution.

FLATOW: We need some more of those hawks coming in to the city. Yes, ma'am.

SOPHIA REESE: Hi, I'm Sophia Reese(ph). I'm 11 years old. And one of my questions is: How do you - how do - how do you know how the subdivision things have been around for a very long time are still living well and having a nice habitat here?

FLATOW: How do we know how long they've been here? Is that what you've been asking?

REESE: Yeah.

FLATOW: Who would like to answer that? Sarah?

AUCOIN: Well, I can answer your habitat question. There's been a lot of efforts over the last 20 or 30 years to restore the natural world in New York City. So there's over 29,000 acres of city-owned parkland in New York City. About 10,000 acres of that is wild and is being restored through a number of different efforts and providing wonderful habitat for many organisms.

So we do see some populations of organisms that have been here for a long time increasing, and that correlates with those restoration efforts. So we do know that there are some populations that are increasing, that have been here for a while, and we continue to work on restoring those areas to make sure that the habitat is suitable so that they can continue to live here.

FLATOW: Thank you - go ahead.

REESE: And also, about the hawks, in Riverside Drive, in Riverside Park, how do you encourage more hawks without damaging the habitat or damaging the people's environment?

AUCOIN: Well, I think that similar to what I was saying before, continuing to work to restore the parks but also we lead a lot of education programs. There's a lot of people in New York City, and a lot of people use New York City parks, but many of them don't know that there are hawks breeding in Riverside Park. So education is a big part of keeping the habitat healthy both for people and for animals.

FLATOW: Thank you very much. Thank you for that question. Dr. Camhi, I was surprised to learn that New York is one of the biggest shark destination, I know, aside from Wall Street.


FLATOW: Why do those sharks love New York so much?

CAMHI: Slightly different populations. We do. We have over two dozen species of sharks, and their relatives, the skates and rays, we have 14 of those. And sharks are - you know, that's drop in the bucket compared to the global population of over 1,100 species of sharks, skates and rays, but these waters are really important. And they're important because they provide a good source of food, and it's a migratory habitat for these animals.

So they move up and down the coastline - and to go to breeding and feeding grounds, and they pass through our waters on an annual basis. They are very much important as part of our recreational fishery. We even have commercial fisheries. And many of the populations, unfortunately, have been very seriously depleted by fishing pressure.

There's a demand for shark meat, as well as shark fins to make shark fin soup, and that has been a driving factor in the shark population declines not only around the world but even here in New York waters.

So we're trying to get an idea of the presence of these animals. I actually have a study where we're putting acoustic and satellite tags on them to watch their movements coming in and out of New York to figure out what is it they're doing here, when are they here, and what habitats do we need to protect if we want to make sure that these populations start to rebuild? And they play an important role in the ecosystem, as well.

So there's a lot of reason to pay attention to them.

FLATOW: And people like to go out and hunt them, don't they?

CAMHI: Yes, they do, yes. We have a very large shark fishery here. It's an important offshore fishery. It has declined terribly. If you talk to recreational fishermen, you know, from - have been fishing for the last five, six decades, they will lament the fact that many of the largest of the sharks - the mako sharks and thresher sharks - have all been on decline.

So we're doing our part at WCS to try to see if we can help those populations recover. And to put it in context, shark attack is not a big problem in New York. We haven't had a shark attack here - maybe one - since 1959. And so we have to set the record straight, because sharks suffer from an identity crisis. We think they're the fiercest animals, but they're also biologically among the most vulnerable.

FLATOW: We're going to bring in another expert now, talking about: Is biodiversity, great biodiversity, good for your health? Dr. Felicia Keesing is an associate professor of biology at Bard College, and she investigated the relationship between the loss of biodiversity and the increase of disease transmission, the subject of a study she co-authored in Nature and 2010. And she's here to join us. Welcome to SCIENCE FRIDAY.


FLATOW: In that study, didn't you find that biodiversity loss really increases disease transmission?

KEESING: We did. We found that that happens for a number of different diseases: diseases of humans and of wildlife and also of plants.

FLATOW: Mm-hmm. And specifically, in an urban setting, what did you find in places where there was a lower bird diversity?

KEESING: So one of the most interesting studies - set of studies, actually - comes from the studies of West Nile virus, which many New Yorkers are familiar with, I think. It actually emerged here about 10 years ago, and people have been studying it ever since and trying to understand why it's more prevalent in some places than in others.

A number of studies have now shown that in areas with high biodiversity, humans are at much lower risk of contracting West Nile virus than in areas of low biodiversity. And sadly, as you've been hearing from the panel members, even though there are lots of different kinds of things here, you've heard that their abundances are going down, and that's a way that diversity declines.

So in urban environments, even if you have a few representatives of lots of different species, diversity is still lower, and that makes the transmission of West Nile virus go up in urban environments. So they're riskier for West Nile virus encephalitis.

FLATOW: And what is the - what's the link here? What's the reason?

KEESING: Yeah. The link is pretty simple. It turns out, to - much to everyone's surprise, I think, that the species that disappear first when biodiversity is lost just happens to be the species that are best at reducing the transmission of pathogens, and the species that persist happen to be really good at amplifying or increasing the transmission of pathogens.

FLATOW: Yeah. Very interesting. I'm Ira Flatow. This is SCIENCE FRIDAY, from NPR, here at the American Museum of Natural History, under the whale. So in conclusion, then, we can conclude that greater biodiversity - and we see that all the time, in every walk of life, right? Greater biodiversity is better for nature.

KEESING: Well, you know, I'm a scientist, so I'm not willing to make such a general claim. I will qualify that to say that there are a number of studies that show that biodiversity improves things that people value. And certainly, one of the most obvious ones that we can value is the protection of our own health.

FLATOW: Mm-hmm. And is there a way to keep biodiversity healthy itself, at least in the field that you're studying?

KEESING: Yeah. We have a pretty simple recipe for that. When we can, the simplest way to conserve biodiversity is to keep natural areas large and undisturbed. The simple rule in ecology is one of the principles of ecology that the larger a space is, the more diverse the species that live there will be. So that's a natural recipe.

The problem is when you have an area like New York where you can't necessarily increase the amount of natural space, then you have to think creatively like many of the panel members are doing...

FLATOW: Right.

KEESING: ...to think about how to make it better within the space you already have.

FLATOW: Dr. Keesing, thank you for taking time to be with us.

KEESING: Thank you.

FLATOW: Dr. Felicia Keesing, who co-authored this paper in Nature about biodiversity.


FLATOW: Let's go to the microphone for our next question. Yes, sir.

ROBERT ROSS: My name is Robert Ross(ph). I heard a year ago or so a presentation on whales migrating off New York. Cornell University put it on. And as I remember, they said there was a place you could actually listen to the whales as they did that. Do you know about that, and where it might be?

CAMHI: Yes. That study is - has - was - operated a couple of years ago. And what Cornell did was they put out listening stations, a line of receivers that could hear the singing of the whales. Some of them are right here in the harbor. And they put a line of them also coming off of Long Island.

And what they were finding is that they were able to hear - and - unfortunately, the funding was cut. They cut the funding. Hopefully, this money is going to be reinstated, and they'll - this work will continue. But they found that four species of whales are commonly heard at least three seasons out of the year here in New York. We have blue whales. We have humpback whales, fin whales. And the most endangered species of whale here in the Atlantic, the North Atlantic right whale, actually comes right through here.

And so it's really important for us to have an understanding about the movements of these animals in these very urbanized waters. We have - we are a huge shipping port. We have more - we're the largest oil port and the second largest container port in the United States. And so lots of vessels are moving in and out of the harbor.

We have to be really careful about how we maneuver our vessels relative to the presence of these giant - these animals, because one of the major threats to the populations in such urbanized waters is ship strike. So by putting these receivers out and listening to the songs, knowing when they're here, we can actually do things to redirect ship traffic, so to reduce the mortality of these great whales.

ROSS: As I remember, what they said, the ships' noises - sonar and radar - also were a problem for the whales.

CAMHI: That's right, because they communicate with each other through sound, the sound of the ships, even things like dredging. We're talking about putting offshore wind power right here in New York waters. All these things could have potential problems in terms of allowing for these whales to communicate, which is important for their social structure.

FLATOW: Thank you very much. We're going to take a break. We're going to come back and talk more with Eleanor Sterling, Sara Aucoin, Jason Munshi-South and Dr. Merry Camhi after this break. Stay with us. We'll be right back. And the audience, step up to the mic, get ready for your question. We'll be right back, as I say, after this break.




FLATOW: You're listening to SCIENCE FRIDAY. I'm Ira Flatow, coming to you from under the whale at the American Museum of Natural History here in New York. And we're talking about the things you can see, the biodiversity, the animals, flora and the fauna that you can see if you just pay attention and how they affect and how they are affected by urban life. Let's go to the audience for a question, here. Yes, ma'am.

UNIDENTIFIED WOMAN: Hi. To get small, I live up in Sugar Hill, near Highbridge Park, Jackie Robinson Park. And on our block, a couple of years ago, appeared some of these new trees. So, you know, we have some little - new little imported trees. And one day, walking along, I found a giant stick bug at the bottom of one of those. And I guess, at the time, I just assumed it had traveled in on a car or something. But I'm just wondering: Are there stick bugs around here? Or...


FLATOW: Stink bugs?

UNIDENTIFIED WOMAN: Yeah. It was a big - big guy. And if not, how much...

FLATOW: How much do you have to worry?


UNIDENTIFIED WOMAN: No. How much did those little trees impact the environment around here? Are they good habitats for things, or are they just kind of pretty?

STERLING: Are you talking about - is this a street tree that was planted in the streets - on your street?

UNIDENTIFIED WOMAN: Yeah, it was a street tree, yeah.

STERLING: So it was probably part of the Million Trees Initiative.


STERLING: We have lots of stick bugs in our nature centers. I can say that for a fact.

FLATOW: What is a stick bug?

STERLING: A stick bug. It's a bug, it looks like a stick.

FLATOW: OK. There you have it.


FLATOW: Thank you very much.

STERLING: And I would say that, yes, those trees and the tree pits are rich with biodiversity, and they're rich with opportunity, as well. The trees themselves play a very important role in controlling temperature, in helping to clean the air, in cooling the city. But, as well, I think I made reference to this earlier, for many people, the tree in front of their apartment - which they may not even recognize is there at this moment - may be their only experience with - their closest experience with nature every day. And we do a lot of education about street trees and in tree pits. And we find a lot of very interesting, you know, especially when you're with kids, you can find lots of interesting organisms in a tree pit.

FLATOW: Thank you. Eleanor Sterling, at the Museum of Natural History here, do you have exhibits that kids can get into, that they can learn about the urban ecology, and they can learn about what to see in their neighborhoods?

STERLING: Absolutely. And the great thing is that very soon, right next door, the Teddy Roosevelt Memorial Hall is going to be opening up again, a renovated hall, and you'll have the chance to really see not just New York's escapes, but also the United States, at the time of teddy Roosevelt, all those vast open spaces. And some of them are so wonderful and open, and some of them are changed. You're going to be able to learn about that. So lots of different kinds of opportunities at a museum to live the environment, and also lots of programs to get kids out into the parks. It's a wonderful opportunity.


STERLING: The other thing that's great about the Million Trees is that those trees don't just help clean the air, but they also clean our water. So our stormwater - we save about $35 million annually on those trees being present in New York City in terms of stormwater maintenance that we don't have to do because of those trees.

FLATOW: They soak up the water.

STERLING: They do.


STERLING: They help the rain - they keep the rain from running off the pavement and into our stormwater management system.

FLATOW: So you have to un-pave paradise, and put the trees back.

STERLING: That would be lovely, actually. And Merry and I did an exhibition here on water a couple of years ago. Merry was the content coordinator for that. And we learned some very eye-opening facts about how much - when a major storm comes through in New York City, unfortunately, your stormwater capacity is such that they basically have to open up the sewers and dump polluted water into those streams and rivers and waterways that Merry's carefully trying to work with other people to manage now.

FLATOW: Can you see any evidence of global warming, any effects on the wildlife in New York or migration or - between any of the birds or the animals or the plants?

STERLING: Yeah. We're definitely seeing birds coming earlier than previously. I didn't mean to jump the gun. I'm sure you can jump in here, too, with other stories. But plenty of evidence of mismatches and timing, where food sources for some of the organisms aren't yet available when the organisms are here, or vice versa. And all of these - nature is so tightly wound in terms of the pollinators and the organisms that create food for those things. And so we're definitely seeing evidence, at this point, of mismatches in timing, in particular, in the spring.

FLATOW: Anyone else? Well, you can jump in if you'd like to. Dr. Camhi, how about the waters? Can you see evidence like...

CAMHI: Yes. We are beginning to see signs of impacts of climate change. We have similar kinds of things in terrestrial environment, species moving sooner, moving faster. We have more tropical species coming more frequently up into our waters.

FLATOW: Such as?

CAMHI: Well, we have - you know, they - a lot of these animals come in because they're actually caught on things like the Gulf Stream, and then spin off and end up, you know, we'll end up with lionfish, for example, in the Great South Bay of New York. But there are shifts happening. And I think the key - and another example might be lobster. Lobster underwent a big crash here in New York a number of years ago because of disease. But what we're finding is even though the disease issue has sort of been dissipated, we're not able to actually re-establish our lobster population here, or our fisheries. And we think it has to do with the fact that maybe there are slight temperature differences, since we're already at the extent of the - the southerly extent of the lobster range. We may not have a lobster fishery in New York for very long.

FLATOW: Was that Long Island Sound or...

CAMHI: The Long Island Sound, yes.

FLATOW: Yeah. Well, that, yeah, that was huge fishery. Yes. Step up to the mic, please.

SALLY FINS: Hi. I'm Sally Fins(ph) and I live in the East Village, and there's an elementary school that's getting started with a green roof for this fall. And so it's triggered me look up some things about gardening on rooftops in New York and what people are doing, even beekeeping. My question is: How can people choose plants that are good for the environment in New York City, or good for the wildlife here? Is there a place where they can look that up, or do you have any recommendations?

CAMHI: That's a great question. And those rooftop gardens are a wonderful opportunity for people. That is such an unused space in New York City, and we have a lot of roof. And I think that a better understanding how you can plant those rooftop gardens so they can support biodiversity and not necessarily just use the one species that we're very familiar with, sedum, that grows very well in the rooftop gardens. To really foster the pollinators, the native pollinators that live in the city and things like that, is a really a great idea.

There are native nurseries to the region that you can look up online that'll be able to help you figure out what used to grow here. There's some wonderful things in the Central Park Conservancy Library that tell you what plants and organisms used to live here in the city before we paved it over. So lots of different resources from libraries to nurseries to the park.

AUCOIN: Yeah, the Parks Department actually runs a native nursery out in Staten Island called the Greenbelt Native Plant Nursery. And there's a lot of efforts within the department and within the city to plant green roofs on agency buildings and city buildings. So there's a lot of knowledge there, as well, that you can find information on the website, and you can also contact us.

FLATOW: Thank you. So a lot of rooftop gardens, and we actually have a video on our website at sciencefriday.com of some great rooftop gardening going on there. Oh, we have a - she's back with a question.


UNINDENTIFIED CHILD: I have two questions. One of them is about (unintelligible) and the birds. How do you help them with the - with their food guy is not unavailable all the time, and how do you help them with that to restore their habitat? And also...

FLATOW: You seem you are very worried about birds in New York, aren't you? Why?

UNIDENTIFIED CHILD: Well, in science, my teacher did a whole unit that (unintelligible) because she's new - about butterflies and birds. So, yeah. And also, about the Hudson, is that being helped, like, a lot? Is it being improved?

FLATOW: Yeah. Let's start with the Hudson.

CAMHI: Yes, the Hudson. So the...

FLATOW: It's not a river, is it?

CAMHI: It is a - it's a river.

FLATOW: An estuary.

CAMHI: Well, no, we have the Hudson River, and then it opens up as it reaches the harbor, becomes an estuary. And we have about 200 species of fishes that live in that water and lots of other animals that depend on it. We certainly have depended on it for many years, to the point, you know, as you all are aware, we have dumped terrible, terrible toxic chemicals into those waters and sewage sludge and all kinds of abuses for centuries. But the good news is that - and unfortunately, it is the largest Superfund site in the United States that's not on government property. But it's getting cleaner, and it's getting cleaner largely because we have regulations like the Clean Water Act of 1972.

And really, the river has improved tremendously. Many species are coming back, and we may be seeing evidence of the importance of some of these increase in numbers of animals in even things like seals, as you mentioned earlier, are now coming back to New York waters. You can go out on a boat and see them - a population of seals every winter on Swinburne and Hoffman Islands in the harbor. So the river is getting healthier, but the bad news is that we have a long way to go.

FLATOW: Thank you for that question. I understand that there are eels in the Bronx River...


FLATOW: ...that make the trip all the way to the Sargasso Sea close to Bermuda.

CAMHI: Excuse me?

FLATOW: Close to Bermuda, out there in the Sargasso Sea. They go from the Bronx River.

CAMHI: That's right. All - there are eels up and down the entire Atlantic seaboard. Almost all of the tributaries in the Atlantic can support eel populations. They all come from one place, and that's the Sargasso Sea, a very large area off the coast of Bermuda and the Bahamas. And eels have a phenomenally interesting life history strategy. They're all born there. The eggs that are laid there become larvae. The larvae are transported on currents, on ocean currents, to the coast lines that are distributed up and down the Atlantic coast.

When the larvae enter the estuaries like here in New York, as well as right in the Bronx River and Long Island Sound, they turn into glass eels. These are really quite adorable little five-inch eels that have - that then move into freshwater systems, and then spend their entire life growing in freshwater rivers like the Bronx River, which is the only freshwater stream in New York City. The thing is, the big problem for these eels is that they - because they lived in fresh - they start their lives in salt water and have to move into freshwater, there are a lot of problems along the way. And the biggest problem we have with the eels right now in the Bronx River is that there are dams there.

And eels are not like salmon, who have a similar life history strategy. They can't jump above a dam to get to the important growth habitat that they have up in the headwaters. And so we are trying to help them as part of the Wildlife Conservation Society by monitoring the populations and putting in nets to allow them to climb up over these dams so that we can try to reestablish an eel population right here in our own background.

FLATOW: Can you see them if you go to the Bronx River? Can you see the...

CAMHI: Well, you will be able to see them now, because last week, we put in our first fyke net. We sample it every day. It's a net that catches eels in little bags. We're opening up and looking to see what we get. And tomorrow, we're putting in our second one. So if you want to come to the Bronx River, give me a call, and we'll take you out and look at the eels.

FLATOW: Fieldtrip to the Bronx River. I'm Ira Flatow. This is SCIENCE FRIDAY, from NPR.

Well, get - you get the bus? Who's calling the bus for that trip? Well, one last question from the audience here. Yes, ma'am.

UNIDENTIFIED WOMAN: Yes. Hi. I am really excited to hear that we actually have a system with the parks that allows people who are planting their own gardens to learn what biodiversity they need to help support. But I'm interested in learning how you guys are working with new parks that are being constructed to introduce biodiversity such as the High Line. Have you been involved in that at all? And if you are, what are your interests in making that do some work for you?

CAMHI: Well, I'm not personally involved in the High Line, but in general, in new park construction, there's careful consideration to the biodiversity that's planted there as well as to the needs of the parks. So we're always balancing the needs of people and the needs of nature. So there's definitely an interest in ensuring that we're bringing in native species and species that are also resilient and that are going to be able to live in an environment that has a lot of people coming to visit regularly, but that can support biodiversity. So there's a, enormous division - I mentioned it earlier - in the Parks Department that focuses on the restoration of existing spaces and on making recommendations for planting in new spaces. So it's certainly something that we're thoughtful about.

FLATOW: All right. We've run out of time. I want to thank all of my guests, Eleanor Sterling, Sarah Aucoin, Jason Munshi-South and also Dr. Merry Camhi. Thank you all for taking time to be with us today.

CAMHI: Thank you.

AUCOIN: Thank you.

MUNSHI-SOUTH: Thank you. Transcript provided by NPR, Copyright NPR.