Scott Taylor: Our house ran on a wood stove all winter, cozy warm. In summer, we build campfires on the beach, roasting hot dogs and marshmallows while the waves rolled in off of Lake Huron. Forest fires were a distant rumor through the 80s, the 90s, even into the 2000s. They were never something we worried about, never something we even smelled. Things are different now. I live in Colorado. In these days, the smell of smoke means worry. In 2020, the state had its two largest wildfires on record, and that kind of day is getting more common. Of every major wildfire in North America since 1950, about 61% have burned since the year 2000. This year, Colorado came out of its warmest, driest winter in 130 years. And much of the western United States is in drought. So things are burning here and across Canada's boreal forest. And even if you live nowhere near a fire, you know when one is burning. Recently, smoke out of Ontario shoved air quality indices past 200 in Toronto, DC and New York. Anything above 150 is a problem. Chicago hit 747. To be fair, fire belongs in some places. The forests near me here in Colorado evolved with it, and some trees depend on it. Lodgepole pine needs a fire's heat to pry its cones open, but in a hotter, drier, more volatile world, wildfires are getting bigger, meaner and harder to ignore. Even from the middle of Manhattan. We're all feeling it. And so as you'd guess, are the birds. Which brings us to the topic of today's episode: Okay, but how does wildfire smoke impact birds? To help unpack that question, I'm joined by Dr. Olivia Sanderfoot, one of the researchers who helped pioneer the study of smoking birds. You may remember Olivia from a previous episode when she walked us through. Whether all those backyard feeders are helping or hurting, this makes Olivia the first repeat guest in Okay, But... Birds history. After the break, she explains whether birds actually flee bad air or ride it out, what smoke does to their bodies and why a hazy sky changes, which birds we can even find, all with fire seasons stretching longer. Stay tuned.

Scott Taylor: Well, welcome back to the podcast. Everyone, I'm really excited to have Olivia with us again, this time to talk all about smoke. Thanks for joining us, Olivia.

Olivia Sanderfoot: Thanks so much for having me, this show's great.

Scott Taylor: I'm glad you like it. So I thought we'd just start off with the fact that Ithaca and much of North America has recently been blanketed in a lot of wildfire smoke. I guess the first question is, when smoke rolls in like that, which can be pretty sudden, what's happening to the birds that we might or might not notice?

Olivia Sanderfoot: We get this question a lot, and the reality is that we don't have great insight into what birds are doing during wildfire smoke events right now. But what we do know tells us that they are responding in unique ways, that their responses are species specific, and that they are likely engaging in some sort of coping strategy to deal with smoke. In general, bird activity seems to decline when it's smoky, although that's not universally true across all species. And inevitably, any bird that is experiencing this intense of a smoke is going to experience some adverse health outcomes.

Scott Taylor: I guess my first instinct would be that birds would just get out of there, although sometimes these smoke incursions are really, really quite broad geographically. But do they just leave or what's the pattern there?

Olivia Sanderfoot: So this is the crux of my research. So during my postdoctoral fellowship at the University of California, Los Angeles and the Natural History Museum of Los Angeles County, I started to develop what we call the Stay-Shift-Go framework for bird responses to wildfire smoke. And really, this could be applied to wildlife across taxa. And the idea is that birds and other animals have essentially three options when they encounter hazardous smoke. They can stay, they can shift, or they could go. The first option is to stay. Birds might do absolutely nothing differently. They might stay exactly where they are and go about their day-to-day life as if the world is exactly the same as it was before the smoke hit. I think that's unlikely and we're not seeing that in the preliminary data that we have.

Olivia Sanderfoot: Birds might also shift. So maybe they don't leave, maybe they continue to occupy their territory or stay within their home range, but they change their behavior in some way. And this might be intentional. It's possible that birds have evolved responses to smoke that help them reduce their exposure. So we're told, you know, when it's smoky outside to stay indoors, run our AC, run those air filters. Don't go for a run. Don't do that marathon you know you had booked for months. So in in essence, if birds are able to hunker down and reduce their activity, they're doing exactly what we're told to do by public health officials. And maybe they know instinctively to do that. They might also just feel really crummy and end up doing it anyway. Just like, you know, you might stay home and rest if you have a cold or a flu because your body just needs that, that extra time to recoup.

Olivia Sanderfoot: The other option is that they do leave, right? They might just say, OK, the air here is terrible. I feel awful. I need to find cleaner air. And I think for bigger bodied birds that are capable of long distance flights, that is possibly what they're doing. But I think it's unlikely that our smaller songbirds that don't do those long distance flights unless it's time to migrate are making that choice. Then again, maybe when the smoke is hitting in fall during migration, the smoke is a cue to leave earlier. So all of these things are possible. And it's also possible that birds are doing a fourth option, which is that they are seeing the smoke from far away to the airspace above them is clean, but they see a smoke plume in the distance and they're actually moving toward the smoke. And this would be true for birds of prey that identify that that visual cue of smoke as a signal of resource availability. They know that smoke means fire and fire means prey, that there are small mammals and insects fleeing the flames and that that smoke signals where they are. And if they go there, they might see an influx of of food resources. So lots of options. And it seems like birds are doing a combination of all of these.

Scott Taylor: Things the fourth option, which is one I hadn't thought about in the context of North America, grass fires in Africa with those like images of secretary birds just, you know, kicking the out of snakes that are fleeing, fleeing the fire. But I suppose it makes sense, you know, in in Australia and as well as North America that some predators would seek out those those fire edges to to try to hunt for sure. And then like you said, the the life stage must matter so much. Like, yeah, if it's around migration time, you're already ready to do these longer distance flights. But if you have a nest or if you have, you know, a territory that you're defending, that's going to be a different calculus on whether, you know, OK, I'm going to just up and leave versus not. Regardless of of that, I suppose if the birds are experiencing the the smoke, so say they don't go anywhere, they're there for whatever reason. Do we understand how wildfire smoke actually affects the health of like an individual bird? Can we see measurable changes like in individuals that have experienced a smoke event versus those that haven't?

Olivia Sanderfoot: Yeah. So first can we talk about how birds breathe? Because it's pretty cool.

Scott Taylor: We have to, we sort of have before, but I think let's let's do our best to explain how birds breathe and I'm going to let you.

Olivia Sanderfoot: Go OK, so humor me for a second and take a deep breath. So when we breathe, our lungs expand and contract. We take in air, our lungs fill with air and we expel stale air. We breathe in and out. And this isn't how birds breathe at all. Instead, they have rigid lungs that sit in their chest cavities surrounded by a system of air sacs that constantly push fresh air into their lungs. So not breathing the same way we do at all. Instead the pulse of air through this unidirectional flow is is channeled by the wing beats, by the movements of their wings. And this allows them to constantly take in fresh air from their environment and essentially allows them to take up about twice as much oxygen with each breath compared to us. And this is great because it gives birds that kick of oxygen that they need to power all the amazing things that birds do, including flight, which requires a huge demand for oxygen.

Scott Taylor: Yeah, totally.

Olivia Sanderfoot: Yes, but it is also a double edged sword because it means that birds are especially vulnerable to all of the toxic gases and particles that are in the air too that they are also taking up at a higher rate. So we do see that birds succumb to air pollution more quickly than we do, more quickly than mammals do generally. And then there are also there's expected variation across species too, so that the smaller bodied birds with the highest metabolic rates or the birds that are increasing their respiratory rate to power these long distance movements, they might be more vulnerable than larger bodied birds with lower metabolic rates that are sitting still.

Scott Taylor: Right. The ones that can maybe chill out a bit more versus the hummingbird that's zipping around trying to stay fed. Interesting.

Olivia Sanderfoot: Yeah, yeah. And so what we know about how air pollution broadly and wildfire smoke specifically impacts the health of birds largely comes from veterinary medicine and poultry sciences because there haven't been that many papers in ecology that have explored at a at a large spatial scale, how individual birds are coping with smoke in the wild. We do see that birds exposed to smoke from structural fires, from sick, they experience respiratory distress, they are more likely to succumb to illness, especially respiratory illness. And so those health outcomes we expect would take place in the wild too, when birds are exposed to wildfire smoke. I was part of a study led by one of my undergraduate researchers, Anna Niehey, in collaboration with Morgan Tingley and Katie LaBarbera back in 2024, leveraging long term monitoring data from a banding station in the San Francisco Bay Area to look at how repeated exposure to smoke impacts bird health over time. And we saw the individual birds repeatedly captured at that banding site that were exposed repeatedly to smoke between captures actually lost body weight. They they were in lesser condition upon repeated captures.

Scott Taylor: Studying wild birds, obviously you have to catch them more than once in order to see like, OK, we know how you. Are you've? Experienced smoke let's look at you again. It's a much harder thing to do than yeah poultry work or work on any kind of captive bird that might be experiencing smoke exposure. So it's really cool that you even got recaptures to be able to measure like, yeah, there is there is this measurable impact on overall body condition.

Olivia Sanderfoot: We were also lucky that that banding station operated during the fire and smoke season. A lot of banding stations are operating during spring right where there's a short term station set up for a very specific field study. It isn't that common to have a year round banding station with enough data available to explore interannual shifts in health and behavior in individual birds.

Scott Taylor: OK. Yeah, yeah, totally. So there's these individuals individual condition issues. So if a bird experiences smoke, because they have a different respiratory system than us, they're quite sensitive to air quality. We don't have pinned down exactly the impacts of wildfire smoke necessarily. And I would imagine that a lot of birds that experience exposure, if they're suffering, they may just die and then we wouldn't be out in the woods to find them. But beyond individual health and and so on, your study in New York, and correct me if I'm wrong, found that smoke changed how often people actually observe birds. So like pretty significant declines in observations of breeding species during smoke events. Talk to us a little bit about that. Like, are they shifting behaviors so then you're not detecting them because you're listening for singing? Or are they actually just like amount?

Olivia Sanderfoot: So the probability of observing birds changes as air pollution increases, specifically as fine particulate matter, which is a well known marker of wildfire smoke, intensifies. These studies look at the overall probability of observing birds across a wide range of species in the states of Washington and New York, and looked at how day-to-day changes in fine particulate matter exposure impact that probability. And we found that many, many species are either less likely or more likely to be observed when it's smoky outside. Now, if it was just us, if I went outside and it was smoky and the only reason why I wasn't able to detect birds is because I felt crummy or couldn't see as far, I would only expect to see fewer birds, right? Like, I can't imagine that any impact on me would be positive.

Scott Taylor: Can't imagine I'd become a better birder when it smells terrible.

Olivia Sanderfoot: Yeah. Exactly, that doesn't, right? Like, I feel crummy, I'm sneezing, I'm coughing, I can't see as far. The sky is like an otherworldly color and I'm somehow a better birder. Like, I doubt it. So the fact that we see both actually reinforces that something's going on with the birds. So some are probably shifting their behavior. Some of these birds might be leaving. I can't tease that out in this study, but they're doing something differently that is impacting their probability of being detected. And what's really great about Festus's recent work is that the taxonomic post hoc analysis is starting to pinpoint which species are doing what, which kinds of birds do what. And I think what's most notable is that cryptic forest species like warblers tend to be detected far less frequently. And this dovetails with some other work that's shown that birds are less likely to vocalize when it's smoky. And a lot of those birds are ones that we detect by ear.

Scott Taylor: So you said some birds are harder to detect, others are easier. So, And from a taxonomic perspective, which birds are easier to detect when it's really smoky out?

Olivia Sanderfoot: So we seem to be seeing an early signal that some larger birds, particularly water birds, might be more readily detected when it's smoky. We're also seeing some common feeder birds that are more easily detected when it's smoky. I think tufted titmice were on our list. We don't have a clear explanation for that. There could be many different reasons. One possibility is that there is a shift in our own observations. Perhaps we're turning our attention to different birds. Is the birds that we used to cue in on have disappeared from the soundscape, for example.

Scott Taylor: Yeah, that's a good point.

Olivia Sanderfoot: It's also possible that different birds are responding to various stressors in their environment in unique ways. So for example, let's say that a common bird of prey decides to leave, decides this is too smoky. I can barely see to hunt. I'm going to go to a different place. I'm a large bodied bird. I'm capable of of powering my flight right now through the smoke. I'm going to try to find cleaner air, whether or not it's available. Maybe they leave a location in pursuit of cleaner skies. Now maybe these smaller feeder birds are like, cool, that hawk isn't hanging out here anymore. I can go to this feeder, I can go feed in the the leaf litter under that tree, and I'm less spooked by the presence of these predators nearby. I don't feel like I need to be as cryptic.

Scott Taylor: Yeah, yeah, I'm curious. So we recently talked about the dawn chorus on the podcast. And so, you know, you're alluding to the fact that wildfire smoke is is even impacting that if these warblers we rarely, especially once the leaves are out in the east, you're not typically watching warblers anymore. It's time to listen to them. So wildfire smoke is a affecting frequency of singing then?

Olivia Sanderfoot: Yeah. So a few papers have come out that show that in general, wildfire smoke is causing soundscapes to become quieter and less diverse. And one study that I read came out in 2017 from Southeast Asia actually showed that measures of acoustic activity that largely represented insect and bird activity remained depressed for 16 weeks after a hazardous smoke.

Scott Taylor: I was wondering, yeah, I was wondering what like, you know, there's the immediate impacts, which we noticed the most. Because it's this. Yeah, like you said, the otherworldly sky, you can't see the sun. But I was curious how long those impacts.

Olivia Sanderfoot: 16 weeks is a really long time, especially if it hits a really long time, like when you're trying to raise chicks or when chicks are out of the nest and trying to grow up. So that could have huge impacts on populations.

Scott Taylor: Wow.

Olivia Sanderfoot: Yeah, and my colleague Dr. Wendy Erb, who studies orangutans in the Bornean rainforest, has also looked at how the vocal quality of orangutan long calls changes during smoke events. So obviously orangutans are not birds, but I think it's really interesting to think not just about the extent to which animals vocalize, but how their calls, how their voices change when it's smoky. There's research that shows that folks who smoke, people who who smoke cigarettes have raspier voices, and we're seeing that in orangutans exposed to wildfire smoke. So that could be influencing their signaling, their communication. If that translates to birds, if the quality of birdsong changes because of smoke, that's a really big deal in terms of how pairs are formed, how birds communicate, risk, how they find each other, protect each other. It's something to think.

Scott Taylor: About totally, especially if exposure to smoke, like at one point in your life, fundamentally alters the way you sound like for the rest of your life.

Olivia Sanderfoot: Absolutely. There's actually a really great study that came out in 2017 that looked at the the long term health outcomes of a wildfire smoke event experienced by infant monkeys living at a large primate Research Center in California. And this research showed that those baby monkeys who grew up and entered adolescence having experienced this early smoke exposure actually had reduced to lung function into adolescence compared to those infants that did not. And the goal of this work to was to really illuminate pediatric health outcomes, but I think we can learn from it for wildlife conservation as well. These early experiences in truly hazardous smoke seem to potentially have health outcomes that carry forward with an individual, potentially inhibiting their health and their reproductive success for years.

Scott Taylor: Yeah. And why wouldn't that be the same for birds that have this really different but very highly adapted respiratory system that they would be sensitive as chicks in the nest potentially to to smoke exposure as well? What is it like out there when you're working on these questions and trying to understand how smoke impacts wildlife?

Olivia Sanderfoot: Yeah, so I have been outside in smoke events. I have largely been outside in smoke events to learn more about what birds are doing when it's smoky for personal reasons and to fuel and inspire my research. I've been very fortunate as to not actually be outside when it's smoky for field work yet, but I have many colleagues who have so. So I can't take credit for the bird banding piece of that robin study that came out. My colleague Dr. Jamie Cornelius was the one who went out and actually banded the birds. And she is bad and amazing. And she actually tracked robins during terrible air quality conditions. I I'm just blown away by her grit and bravery. She's a phenomenal scientist. This is one of the reasons why it is so hard to study how wildfire smoke impacts birds because either you have to leverage long term monitoring programs like the data that's collected at bird banding stations, like the data that's collected in participatory science programs, and wait to be able to construct an opportunistic study leveraging those platforms. Or you have to plan field studies and a hope it's smoky when you planned to be in the field, which is an odd thing to hope for and be outside when every single public health official is telling you and your team that that's unsafe and by being outside you are jeopardizing your health in some way and take every precaution that you can. So Jamie was out there banding robins and tracking robins and chasing robins and smoke with a mask, protecting herself as best she could to get this data that told us something about what robins were doing when it's smoky. And I really commend her for providing the field data that was necessary for that analysis.

Scott Taylor: These incursions of smoke are becoming more and more common. Fire seasons in the West are extending. We're having more and larger fires and the time of year that these are happening are extending into, you know, bird breeding seasons, which I know you're interested in. What should we be trying to do as this becomes a more common thing that we're experiencing?

Olivia Sanderfoot: We all need to expect that the future will be smokier and we need to take precautions for ourselves and we need to do more to protect wildlife. So to protect ourselves. If you are able to, it is a good time to purchase an air filter. As far as the birds go, I'm actively researching exactly what they need from us, exactly what we can do to help, and I have two particular conservation actions that I'm investigating. The first is identifying and protecting smoke refugia. I want to know where birds retreat to when it's smoky. I want to know where they flee to during fire and smoke events so we can protect those habitats and build corridors from places with known fire and smoke impacts to places where we expect fewer fires to take place and where the air quality is generally better. How do we support birds in accessing the places where they need to hunker down when the air is gray and full of toxic particles? We're working on that more soon.

Olivia Sanderfoot: Other thing that we're looking into is which resources birds seek out when it's smoky. And I'm particularly interested in use of feeders and bird baths for a few reasons. One, I collect observations from folks all over the world and, and what they're seeing during smoke events and I hear wildly different things about use of feeders in bird baths. And some folks write in and they say there are so many birds in my bird bath. Oh my goodness. Are they here because they they need this water? Are they desperately thirsty? Should I put out more bird baths? And then I have folks who say no one's at my bird bath today. Where are all of my birds? And both of those things could be true, right? Both of those things could be true depending on which birds, how close you are to the fire, how close you are to the smoke, what's in the smoke? How toxic is it? What does it smell like? What's the visibility? Can they find this resource? They could all be true.

Olivia Sanderfoot: But if we found that birds under certain smoke conditions need more supplemental water, need more supplemental food, maybe their resources are being burned and consumed in these fire and smoke events, and putting out a little extra seed actually is a boost that will help them, wouldn't that be a great thing to know, be able to tell people? So we're actively working on that, both with data from Project Phoenix, which is a community science project run at the Natural History Museum of Los Angeles County that I founded during my postdoc, and Project FeederWatch here at the Cornell Lab. I know that winter time monitoring doesn't feel like they're best fit for this, but as you mentioned, like the fire season is year round now. So my student Asher's using the FeederWatch data set to better understand responses to fire and smoke during the LA fires using the FeederWatch data set.

Scott Taylor: Totally, yeah. Tell us a little bit more about Project Phoenix. We've talked about Project FeederWatch before, and I'd encourage everyone to go listen to the last episode that we had Olivia on. But tell us more about Project Phoenix and what the data collection looks like, what you're looking for from your participants, how they get involved in the project.

Olivia Sanderfoot: Project Phoenix is a community science program that engages folks from the West Coast in monitoring birds during the fire and smoke season, and you can be an expert birder or brand new to birding. Whether you have picked up binoculars before or this is the very first time you've ever thought about birding, you're welcome to participate. We're actively encouraging beginner birders to get involved. Our ask is a 10 minute point count once per week at a place of your choosing so you can pick the location. Ideally, this is some place that is convenient, easily accessible, and personally meaningful to you. It's a place where you want to get to know your birds a little bit better. And you visit that location and conduct a 10 minute count of all the birds that you see or hear. And you add that information to an eBird checklist. At the end in the comment section, you add hashtag Project Phoenix and submit to eBird. And then on our side at the Cornell Lab of Ornithology, we extract that data and and add it to our analysis of the Stay-Shift-Go framework. We also ask that volunteers submit a brief site description to tell us a little bit more about the supplemental resources that they're providing to birds. Namely, do you have a bird bath? Do you have a seed or suet feeder, and do you have a hummingbird feeder? And we're using that to collect very fine-scale data on supplemental resource availability to birds. There's no publicly available data set on who's putting out feeders or bird baths. So that is something we ask our participants for, and that's in and of itself a really unique resource that we've been leveraging for a few different analysis.

Olivia Sanderfoot: Honestly, participatory science is the key to unlocking this mystery. I believe that I've pushed that for a long time now. It's so hard to get in the field when you need to, and it's so hard to conduct studies at the scale necessary to capture smoke events. But if people are collecting data on birds from their place where they are and keeping themselves safe, right? We just ask you for both Project Phoenix and Project FeederWatch. You can Bird from your window if you feel more comfortable doing so. You don't have to step outside when it's smoky. Even the observations from your window are useful to us. And you can also go outside for, you know, 10 minutes wearing a mask for your Project Phoenix checklist this summer. And that would be that would be just fine. You'd be keeping yourself safe. 10 minutes is is really no big deal. Of course, we'd never pressure anyone to do that at all. If you feel more comfortable, stay inside. But it those 10 minutes make a really big difference for us because that's what we're using to build these retrospective before, after control impacts this.

Scott Taylor: Cool. Yeah, I'm going to sign up. That's awesome in that it's just through eBird is amazing, such a great resource. We've reached the part of the show we call That's B.S. or That's Bird Stuff, where we give our guests an opportunity to debunk a myth that ruffles their feathers. So Olivia, what do you want to call B.S. on this time?

Olivia Sanderfoot: I'm going to call B.S. on all fires are bad. I think this is still something that is part of the public psyche and it's hard not to feel devastated and overwhelmed when the headlines are about catastrophic fires. It's hard not to think, well, wildfire is bad when you see pictures of 40 foot flames and thunderstorms and smoke. It's hard, I get it. But the truth is that most of the ecosystems that we know and love here in North America do require fire. The problem is that the fires that we're seeing now are larger and more intense and cause more severe damage and more widespread smoke than they used to. And this is due largely due to climate change supercharging fire conditions by increasing temperatures. Globally, we're seeing increased vapor pressure deficit, which is causing these forest to dry out, these grasslands to dry out, which makes them much more likely to burn. We are also experiencing the aftermath of a legacy of fire suppression in which European colonizers halted all fires that took place and prevented cultural burning. And that has led to a build up of fuels in these ecosystems. So if you couple these things together, we've got hotter, drier weather and way more vegetation to burn. We're seeing these catastrophic fires. So when we're talking about helping birds through fire and smoke, we're not saying let's stop the fire. In fact, one major strategy in this effort is going to be putting more fire out on the landscape by issuing more prescribed burns, controlled fires that give ecosystems what they need to renew themselves without causing the catastrophic fire and smoke like we're seeing right now up in Canada.

Scott Taylor: Right, yeah, super important points. Thanks so much for joining us again on the podcast. It's been really awesome to you learn all about your research on smoke, and I know wildfire smoke is on a lot of people's minds right now, so thanks again for coming.

Olivia Sanderfoot: Thanks for having me.

Scott Taylor: Birds are dinosaurs and around here we like our snacks, so we end each episode with a Dinosaur Nugget. Today's nugget is when wildfire smoke rolls in. Birds have three options. Stay, shift or go? Some ride it out, some move to find cleaner air in the same area, and some leave entirely. Which one depends on the species, its life stage, and how bad the smoke gets. And because birds breathe through a one way system far more sensitive than ours, even the ones that stay are paying a cost we can't always see. So when the count drops, it's easy to assume they left. But sometimes they're still right there, just harder to find. That's a wrap on this week's episode. Okay, but how does wildfire smoke impact birds? Quick ask before you go. This show is brought to you by two guys and our gracious guests. Help us out by leaving a rating of five stars, obviously, or a follow. It matters more than you might expect. It takes 2 seconds and it makes a real difference. We'll catch you next time. Byeee.

This transcript was generated using AI-assisted transcription and may contain errors or omissions. Please refer to the audio or video episode for the most accurate representation.