Migratory birds use starlight to find their way on their long journeys — which makes light pollution a serious threat. Drawn off course by bright, artificial lighting, birds can wind up fatally colliding with windows or wasting precious time and energy that they need to survive. “Lights Out” programs get cities and their residents to turn off nonessential lighting during migration seasons which can help make their journeys a little easier (and save energy!). BirdCast, a tool that can forecast the peak migration nights of the season, is helping these programs make a greater impact. Tenijah speaks with Julia Wang, project leader at BirdCast and the Lights Out Texas campaign at the Cornell Lab of Ornithology.
Tenijah Hamilton: BirdNote Presents…
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Tenijah Hamilton: It is 10:14 PM on April 25th here in Atlanta. And, um, it's actually a really lovely night. And I'm out here with my husband, which is nice. And it is spring migration time. According to BirdCast there are almost 15 million birds passing over Georgia tonight. Like that's incredible.
Ryan: That's pretty wild, isn't it?
Tenijah Hamilton: And like, what do you see when you look up into the sky?
Ryan: Just the stars.
Tenijah Hamilton: Yeah.
Tenijah Hamilton: We can't really see them, but it's really nice to know that there are kind of these swaths of birds up there making their epic journeys.
Tenijah Hamilton: But in our night skies, there is one deadly danger along every bird’s journey: light pollution. As many as one billion birds die from window collisions in the US each year. A lot of those collisions happen at night, when most birds are migrating. And many species use natural light from the stars and moon to help navigate — so bright electric lights disorient birds and draw them off course towards more developed areas.
Tenijah Hamilton: Just think about how many lights we see from our neighbors right now, and all the buildings between here and wherever the birds are going, um, that are lit up.
Ryan: Mhm. The city just completely blown up with lights and everything.
Tenijah Hamilton: Yeah. Well, I hope that wherever they're going, they get there safe. Stay safe little birdies, little bird friends,
Ryan: Good luck, birdies.
Tenijah Hamilton: Good luck.
Tenijah Hamilton: From BirdNote, this is Bring Birds Back. I'm Tenijah Hamilton. Today we're looking at the challenge light pollution poses to birds. And to guide us through the topic we have Julia Wang with us. Julia is a project leader at the Cornell Lab of Ornithology on the issue of birds and light pollution. Thank you so much for being here today, Julia.
Julia Wang: Thank you so much for having me.
Tenijah Hamilton: So to start us off: for people who haven't thought about it much, it can be a surprise that birds are doing this much at night and let alone these like big, epic journeys. So why are they flying at night?
Julia Wang: Yeah, when I first say that to a lot of people, they genuinely don't believe me. And I can understand that because it's very hard to see birds flying at the heights that they do at night. So at night it tends to be that the air is less turbulent, so it's a bit easier to fly. And especially for woodland species that might not be as agile or as powerful fliers, it's easier to fly at night. It's also typically cooler at night, so it's easier to off-put the heat that's generated when you're flying really, really far distances. And there's less predation concern, in that you don't have to worry about hawks and falcons and those sorts of diurnal birds of prey flying at night. So there's a variety of reasons, but it all culminates into the majority of migrating birds migrating at night.
Tenijah Hamilton: So thinking about lights. Lights can really increase window collisions.
Julia Wang: Yeah, window and building collisions.
Tenijah Hamilton: Yeah. Which are often deadly for birds, right?
Julia Wang: Yeah.
Tenijah Hamilton: Are the artificial lights always so directly deadly or are there other ways it's harming birds?
Julia Wang: In the aggregate, all of this light pollution coming from major centers of buildings, homes, residences, pulls birds, generally, into an area where they're more likely to deal with collisions and other urban threats. Individual window bays, um, tend to be more collided with when they're lit than when they're not lit. So it is an individual light problem, as well as an aggregate problem. And in addition, light pollution can sort of affect migration timing to a certain extent. It might affect when birds are leaving or going. And in shifting that they might miss sort of optimal windows of foraging or arrival.
Tenijah Hamilton: And, these lights can also kind of disorient the birds, right?
Julia Wang: Yeah.
Tenijah Hamilton: Like just generally confusing their senses?
Julia Wang: One of the examples we've seen is at the 911 Memorial tribute to light in New York city each year, where 88 7,000 watt Xenon light bulbs are positioned into two 48 foot squares, beaming upwards, visible from a 60 mile radius. What we see every year is that hundreds, if not thousands of birds become attracted to and trapped in these lights, swirling in the columns of the lights until they exhaust themselves, leaving them vulnerable not only to collisions, but to urban predators.
However, we have found that turning off bright lights helps the birds move on in just a few minutes. Cornell and New York City Audubon work in partnership with the Memorial to turn off lights for just 20 to 30 minute intervals when density gets too high. And that leads to the birds dispersing, helping to prevent any collisions.
Tenijah Hamilton: OK so obviously the 9/11 Memorial is an extreme example — like, most homes or even skyscrapers are not shining a few hundred thousand watts straight up into the sky. But that work in partnership between the Memorial and NYC Audubon and Cornell, that's a great example of the key work in solving this issue. Part of Julia’s work is helping organize a "Lights Out" program in Texas:
Julia Wang: Lights Out programs started in the U.S, approximately in the 90s. Since then they've taken on various forms, but typically what a Lights Out program does is try to communicate the problem of light pollution, how it increases collisions and raise awareness in whatever their local geography is. Typically a city. There are over 30 Lights Out programs in the U.S. and they work fairly independently. As far as Lights Out Texas goes, which is the program that I'm involved in, that began in 2017 after a major collision in Galveston, Texas, where there was another building that had a lot of external lighting and was near the coast, during this storm during migration. And in the morning they found about 400 dead birds, just around that single building after a single night. The program began after this Galveston crash, initially as a partnership between that building and Houston Audubon. What we and our partners here in Texas and across the country have been trying to do is to one: measure the collision problem with the collision monitoring program. And also to raise as much public awareness of this problem as possible. Communicating with city offices like sustainability offices and mayoral offices to produce proclamations, asking people to turn off their lights. And with building owners and managers, raising awareness with them, asking them to turn off their lights when birds are migrating and particularly likely to be impacted.
Tenijah Hamilton: So I'm wondering— you said you're in Texas and you're doing the Lights Out Texas program. Why there?
Julia Wang: Why Texas? That's a great question. One of our collaborators at BirdCast produced a study a number of years ago that looked at where birds were most at risk for being impacted by light pollution and therefore light pollution related collisions. And that list was topped by Chicago at number one. And then, Houston at number two and the Dallas-Fort Worth metroplex area at number three. And I believe there were one or two other Texas cities in the top 10 of that list due to the huge volume of migratory birds that Texas is lucky enough to see being on these migratory pathways, forming sort of a bottleneck between North and South America. And due to the amount of light that major Texas cities are producing. And so here we saw an opportunity to produce the most change in an area of critical migratory importance and danger.
Tenijah Hamilton: Since starting Lights Out Texas in 2020, the program has seen incredible growth:
Julia Wang: So, in 2021, we had seven cities and one county in Texas produce proclamations, or in the case of the county, a resolution to support Lights Out. And what that looked like, was typically, the mayor's office of each city sending out a press release saying that, from this date to this date of this migration season, we encourage all businesses and residents to turn off their lights from 11:00 PM to 6:00 AM. It made major news within the state. And just being able to get that in front of people and show them how it's a win-win for everyone was very compelling. And that helped us grow from, I guess, one participating building in Galveston in spring of 2020, to over a hundred in 2021.
Tenijah Hamilton: That's some growth!
Julia Wang: Yeah. Very excited to see it. Essentially it's about identifying local partners who will be your advocates. Because having local people means the most and makes the most difference in on the ground operations and connections and contacts to building owners, managers, politicians, that sort of thing.
So it's partly that, and it's partly about making sure that your message is direct, concise, and tailored to the right audience. And explaining what the problem is. And the fact that the solution is a very simple one. All we're asking is that you flip the switch and turn off some lights during migration season, and fundamentally, it becomes a win-win situation for both parties. You know, you're helping to save birds. And you're also saving energy by turning out their lights.
Tenijah Hamilton: I can absolutely see why that can be a winning strategy, right? Because again, like you mentioned, you're not asking people to do this very big action or to donate or do anything. You're asking them to evaluate what they're already doing and maybe flipping the light switch.
Julia Wang: Precisely. Yeah. I mean, as far as impact versus action goes, this is one of the simplest, most straightforward, opportunities to make a very small change and like, hugely impact bird conservation.
Tenijah Hamilton: You mentioned that you all really work with kind of community partners. Can you talk more about the help that you had in making this happen?
Julia Wang: Absolutely. So we work with a great network of partners. And they've been amazing, in getting that word spread all across the state in a way that no single organization can. We had a great deal of help from our friends at Texan by Nature, which is one of our major partners. We were lucky enough to work with former first lady, Ms. Bush, on Lights Out Texas. That brought some attention to it. And then once attention was on the issue, it seemed like a no brainer to a lot of people. And there's so many volunteers doing the groundwork of collision monitoring, talking to buildings, that no single person can do. Which matters so much more if you know, it's your neighbor, Linda, down the street, asking you to do it, than some random person at a college asking you to. That's been an absolutely critical part of our success. People need to better understand that their lighting at home can make a big difference. That they can make a big difference. And we really need to start there. Talking to your neighbors, talking to your friends, talking to your boss at work. Whatever. It's fundamentally a very grassroots, local movement.
Tenijah Hamilton: But not everybody is on board yet. As I've been looking into Lights Out and talking to friends about it, one of the questions I've heard a lot, and definitely one of the first things I was concerned about is safety — Like, will everything be super dark? Is it gonna make cities and streets unsafe at night?
Julia Wang: That is one of the major questions that we get. And it's a concern that I understand, especially as a young woman walking around cities at night, I understand why people are concerned about crime, those sorts of things. But what I would say to them is that the literature does not support the idea that increased artificial lighting is improving our safety. There is no clear scientific evidence that increased outdoor lighting deters crimes. Might make us feel safer, but it has not been shown to make us safer. I think there was a study published in 2015 in the Journal of Epidemiology and Community Health that found that increased streetlights don't prevent accidents or crime, but do cost a lot of money. So what we're advocating isn't even the total nullification of light, but for better lighting that is more targeted and protects the environment around us and takes into consideration what type of light they're producing. Whether it's a blue light or like, amber light, et cetera, whether that light is shielded and when those lights are on.
Tenijah Hamilton: After the break, Julia and I talk about BirdCast, a super-cool project she works on that's been making a huge difference in getting more people on board with Lights Out. We’ll be right back.
Tenijah Hamilton: And we're back. So Julia, you're the project leader of something called BirdCast at the Cornell Lab of Ornithology. I understand it's making a big difference in both understanding bird migration and in these Lights Out campaigns we've been talking about. To start off, can you tell me about BirdCast — like, what is it, how does it work?
Julia Wang: Basically, the idea is to be able to forecast migration before and during migration so that we have a better understanding of where birds are and when. And the hope for that was, both, that we would know that just so as birders, we have that information that's exciting and fun. And also to apply it to conservation causes like Lights Out. And the way this all works is using something called radar aeroecology. Essentially we take the data produced by radar across the U.S, and then we apply machine learning algorithms to it and we separate out the information about weather systems from the other information that is gathered by radar, which includes ecological information like when birds, bats and insects are in the atmosphere around us. So once we're able to separate out that information, we can start producing models of when those birds are moving and producing maps that predict where birds are going to be over the next couple of days during migration, as well as live maps showing where they are on any given night during migration.
Tenijah Hamilton: When you visit the BirdCast website, there are a bunch of really cool maps you can see — it feels like you’re plugged into the bird Matrix. There's a national map with a forecast for how many birds are migrating for the next three nights, there's a REAL TIME map, where you can see how many birds are flying in different parts of the country, which is wild. And then there are a couple of newer tools that are useful for Lights Out organizing — including local migration alerts and a new migration dashboard:
Julia Wang: Local bird migration alerts, you can enter your city or your county and be given a sort of status update on what migration intensity looks like in your area for tonight, tomorrow night, the night after that. It's a useful tool for, say, building managers or homeowners who just want to check in and be able to see, hey, is migration high tonight? Like, should I turn off my lights tonight? And so that's the function of that tool.
And then this spring, we just debuted a new tool called the migration dashboard, which allows you to take a look at how many birds are migrating over your area specifically, at night. And so you can keep the dashboard up at night and watch the number of birds flying overhead. In the morning, you can see the sum total number of birds that have passed. And then throughout the night, you can also keep track of the altitude birds are flying, the direction, some of the expected migrants that you might see if you go out to bird.
Tenijah Hamilton: That is wildly cool. The fact that there's this tool available where I can literally just— I can tell who's above me, when they're expected to be above me. How I can help protect them. Like, I think that's incredible. It kind of, is like a weather radar, it sounds like. Like I'm tracking these storms of birds.
Julia Wang: Basically. And if they're any weather related people on this and they want to feature our migration dashboard or maps on their stations, hey, get back to me. We would love to see that happen. I would love to be able to turn on the news and see not only what precipitation I'm getting, but what birds tonight.
Tenijah Hamilton: That would be dope. Wow. Yeah.
Julia Wang: But in the absence of that, BirdCast.info, that's where you can get your bird maps.
Tenijah Hamilton: How has BirdCast changed what's possible for getting cities to embrace Lights Out? Has it made it easier to sell to cities?
Julia Wang: I would say yes. Um, it's another tool that enables us to connect with cities and inform them of when things are going to happen specifically for them. Migration season is pretty long: couple of months in spring and a couple months in fall. And functionally, if you think about it, you know, there are always birds migrating. It barely stops. But when we're talking about creating major change in the way that people view and deal with light in their homes and in their cities, as much as we would like everyone to flip the switch all at once — doesn't always happen like that. So what BirdCast is able to do is provide information about when bird migration is particularly critical in your area, if you're not able to commit for say, a full season or the full year or whatever, and you need to target your efforts. One of the ways that we work with cities is providing them what we call peak periods, which is a term that we use to refer to when over 50% of migrating birds are migrating through. Because that usually ends up being a window that's only a few weeks long out of the several months long migration season. And so then we provide that peak window for each of these cities, so they're able to react to those peak windows. So doing that, we're able to sort of target what effort is available in order to get more people on a board. And I think that has been a huge help in onboarding people who don't really know much about the effort; who might otherwise have thought it too big of a commitment. And then once they're on board, you can start providing more education and getting them more on board about light pollution issues in general and moving, hopefully, towards full season and full year commitments and just a changed perspective of the role of light and ecology in our lives. But yeah, you gotta start small and move big, we've found.
Tenijah Hamilton: Absolutely. And for people listening who want to begin to navigate like, the first steps to taking action, what can they do to help reduce light pollution for migratory birds, either at their homes or in their larger communities?
Julia Wang: So I would say, first of all, that anyone can make an impact. That every light and window counts. In terms of what specific lights to be concerned about, how to make changes, I would generally recommend that lights be low, shielded and long. Low, being in altitude. Shielded — that directs the light downwards, rather than light up to the heavens. And long, talking about wavelength, because blue light tends to be the most harmful to animals, et cetera. And wherever possible lights be put on a timer or motion activated so that they're not always on. We generally recommend that lights be off or dimmed or otherwise modified to protect birds between 11:00 PM and 6:00 AM, or longer, if you're able to then. I would just ask that you spread the word to your neighbors, your community, so that you're all doing this together. Look at whether there is a lights out program already available in your community. I believe Audubon keeps a full list. And typically, if you reach out to your local Audubon chapter, they're able to furnish you with specific recommendations and knowledge about whether a program exists or might be willing to help you start one up if there isn't. Also feel free to reach out to us. We're always, always willing to provide information, share resources, to get Lights Out set up in whatever your venue may be. Whether that be your home, your community, your city.
Tenijah Hamilton: So those are really great tips. I’m curious: when you look to the future of this issue, what gives you hope as you're kind of embarking to really change a lot for the betterment of these birds?
Julia Wang: You know, that's a big question. And I think that there's obviously some level of concern from a lot of people because of how light pollution is continuing to grow. But what gives me hope that this is something that is, you know, accomplishable, doable, I think is the response that we've gotten from people in working with them over the last two years. And so that gives me hope as well as the increasing amount of people that are concerned about this issue across industries. I think that this is being talked about, not only by wildlife biologists, ecologists, but also by doctors who are concerned about the effects of light pollution on human melatonin production, and correlations with obesity and sleep disorders, et cetera, et cetera. It's also being talked more about in industry, like in lighting industries, um, in terms of just implementing green design, good design, so that we're not wasting resources. And as we go forward with this sort of ongoing global conversation about global energy usage and protecting our environment, I think that light pollution is becoming more and more of an understood type of pollution treated as other types of pollution are. And so I hope that that trend continues. I hope that we can be a part of it, and help mitigate some of that damage and preserve our night skies and the animals around us.
Tenijah Hamilton: Absolutely. Thank you so much, Julia. This has been real great.
Julia Wang: Absolutely. Thanks so much for taking the time to talk with me about this issue. I really appreciate your shedding some light on this to your listeners.
Tenijah Hamilton: You can find links to BirdCast and Lights Out programs at our website, BirdNote.org. And like Julia said — every window and every light helps. So whether you're able to shield your patio lights so they don't shine to the heavens or you organize a whole new Lights Out campaign in your city, we can all make the future a little brighter — and our skies a little darker.
Bring Birds Back is produced by Mark Bramhill and me, Tenijah Hamilton. Sam Johnson is our production assistant. We're edited by Oluwakemi Aladesuyi and Allison Behringer of Rough Cut Collective. Our fact checker is Conor Gearin. Our Content Director is Allison Wilson. Scoring is by Cosmo Sheldrake, Blue Dot Sessions, and Mark Bramhill. Special thanks to Viki Merrick and Rehka Murthy.
Host and Producer: Tenijah Hamilton
Producer: Mark Bramhill
Editor: Oluwakemi Aladesuyi and Allison Behringer of Rough Cut Collective
Content Director: Allison Wilson
Music by Cosmo Sheldrake
Additional Music by Blue Dot Sessions
Podcast Art by Hayden Maynard
Photo of Tenijah Hamilton by Tasnia Malek
Bring Birds Back is a production of BirdNote. Learn more about the BirdNote team.
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About guest Julia Wang:
Julia Wang is a Cornell Lab of Ornithology project leader whose primary focus is on developing and coordinating Lights Out campaigns with conservation partners and local stakeholders to facilitate widespread public and governmental adoption of conservation practices. These campaigns integrate BirdCast research to better target which nights migratory birds are most at risk from the harmful effects of artificial night lighting, as well as to quantify intervention effect. Julia completed her B.A. in Government at Cornell University, and is particularly interested in the application of research to solving real world problems, and in behavioral change on both the individual and systemic level.