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Cecily Hansen 

Welcome back to the Naturally Speaking Podcast. My name is Cecily Hanson, and today I'm here with Scott Weidensaul, an author and naturalist who specializes in migratory birds. Today we are going to be talking about bird migration. Welcome, Scott, and thank you for joining us. 

Scott Weidensaul 

Oh, well, it's a pleasure to be here. Thank you so much for having me, Cecily. 

Cecily Hansen 

Yeah. So Scott recently visited us here in the North Country to talk to St. Lawrence University students and residents about some of his work with birds. I really enjoyed your visit and your talk, and when I decided on doing a podcast about bird migration, you were the first person that I thought of to talk to. And you have a very long resume. You are a prolific author who's written more than 30 books, including the New York Times bestseller, A World on the Wing, and your most recent book, Return of the Oystercatcher. I also understand that you have done quite a bit of field work. You founded Project Snowstorm, worked with Project OwlNet, and founded the Northeast MOTUS Collaboration. That's quite a bit. And to start off, I'd just like to hear about what else you've been up to lately. 

Scott Weidensaul 

Oh, well, I mean, that's, you've summed it up there. So the snowy owl work with Project Snowstorm keeps me busy during the winter. I've been doing overseeing northern saw-whet owl banding in Pennsylvania. This coming fall will be our 30th year of doing that. We've banded at this point about 15,000 Northern Saw-whet Owls, and we've done radio telemetry, and more recently we've been deploying nanotags. You mentioned the MOTUS Wildlife Tracking System. That's, you know, this new kind of revolutionary approach of using miniaturized VHF transmitters on animals that were always too small for traditional telemetry. So yeah, I've got a had a research project over the years with the National Park Service in Denali National Park in Alaska, which was really cool, including the times we ran into grizzly bears, which was always that gets your blood going. You know, it's just it's been it's been great. And I get to write about this and share this with with the general public, which is just such a privilege. So yeah, it's been great. And it was wonderful coming up to St. Lawrence and sitting on Dr. Willson's class and meeting you and the rest of the students. It was just, it was a blast. 

Cecily Hansen 

Yeah, I was so happy to hear your talk when you came to visit. It was wonderful. So, what got you interested in birds? How did you start out on this career path? 

Scott Weidensaul 

I literally can't remember a time when I was not interested in birds and nature. You know, birders often talk about having a spark bird, which is like the bird that got them interested. I don't have a spark bird. I mean, I've had, there have been spark moments. For example, when I was 12, I visited a place called Hawk Mountain Sanctuary in eastern Pennsylvania for the first time, which was the world's first sanctuary for birds of prey. It's this migratory route on the Kittatinny Ridge where every fall about on average about 20,000 hawks, eagles, falcons, vultures pass by. And we just happened to get like the best migration day of the season that year. And I got totally hooked on raptors. I got totally hooked on migration. I mean, that was really one of those moments, that's a moment where I could point to and say my life changed that day.  

But I've had a very circuitous career path, that would be the polite way of putting it. I dropped out of college without finishing my undergrad, I worked for years as a newspaper reporter, began freelance writing about natural history at a time when I was also doing raptor rehabilitation, and then I got into working with Hawk Mountain's research program banding, trapping, and banding migrant raptors and then doing some radio telemetry with them and then eventually got my own banding permit. And then I started working with owls and I started working with songbirds and eventually I started working hummingbirds, just sort of working my way smaller and smaller as we're going here you know. And after about ten years of newspaper reporting, I quit that job and started a career, that's now more than 35 years ago, as a as a full-time freelance natural history writer doing books and magazine articles about natural history, but especially birds and especially bird migration, bird conservation. So, it's crazy. I mean, I never got that. I never got an academic degree, but I've been well received by the ornithological community. I'm a fellow of the American Ornithological Society these days, which I still find kind of baffling. Like, what's the old joke? I wouldn't want to belong to any club that would have me as a member. I'm kind of surprised they would have me as a member. But yeah, there you go. It's been a fun ride, that's for sure. I'm in my late 60s now, and a lot of my friends are retiring. And I'm like, why on earth would I want to retire? I mean, I'm having way too much fun. This is just a blast. 

Cecily Hansen 

Yeah, that's awesome. So that kind of leads into one of my other questions that I have, because you mentioned tracking and telemetry. So, you say in your book, A World on the Wing, that you're tempted to call today the golden age of ornithology. So, what are the big changes and advances that we've made that enable us to do so much more research on bird migration? 

Scott Weidensaul 

Oh my goodness. It's just this revolution in new tracking technology. And that's something I've been involved in for a long time. Like I said, back in the 1980s, you know, I was helping Hawk Mountain put radio transmitters on red-tailed hawks. And only way that we could track them was to literally put two people in a car with a radio receiver and a directional Yagi antenna and try to keep up with a red-tailed hawk from the ground that's in flight. And I am here to tell you, it does not work well. And we had a little bit of an air force because we had a volunteer fellow named Frank Masters who owned his own private planes and was a radio enthusiast and got permission from the FCC and the FAA to mount radio receivers, the antennas, the Yagi antennas on the struts of his airplane. And when our tracking team would, as would inevitably happen, lose track of a bird, like for example, they'd get stuck in Washington D.C. traffic and the bird would just sail right over top of it. They'd call Frank and he'd jump in his plane that night and he'd fly out after the hawk had gone down to roost for the night. And he might fly all the way to North Carolina from Harrisburg, Pennsylvania and circle around and find the bird and then fly back to Harrisburg and call them and give them the coordinates. And then they'd go down there the next morning. Well, you can imagine that is really hard to do.  

But today there are tracking technologies that allow us, depending on the technology and depending on the bird that you're trying to track, literally follow them on a moment-to-moment basis. I mentioned you mentioned the MOTUS wildlife tracking system. So, these are like hyper miniaturized VHF radio transmitters, all of which broadcast on the same frequency. I used to radio track saw-whet owls, and every owl had a different transmitter, and every transmitter had a different frequency, so you'd be out in the woods at night with like four or five owls that you're trying to track, and you're just jumping from one frequency to the next, to the next, to the next, and trying to find the owl. Okay, there's that owl. The owl's here. It's just, again, just enormously complicated and time-consuming. Well, now, these new nanotags, as they're called, some of which only weigh a fraction of a fraction of an ounce. I mean, small enough you can put them on hummingbirds or on butterflies. And because they're all broadcasting on the same frequency, there's a network now of globally, I think about 2,400 automated receiver stations out there that are listening for that frequency. And when they pick up a ping from that transmitter, embedded in that ping is a coded ID. pulse that will tell the receiver station and eventually the software that's analyzing the data that, okay, this was a transmitter that was put on a White-rumped Sandpiper that was tagged on the shores of James Bay in the Canadian subarctic. Or this is a transmitter that was put on a Grey-cheeked Thrush that was tagged on the wintering grounds in the forests of Colombia and is coming back north again. And it's all automated so you don't have to, you know, you're not sitting out there at two o'clock in the morning trying to track an owl in the middle of the night, freezing your butt off because it's January and it's 14 degrees and the wind is blowing.  

But I mean, there are actually now transmitters made by the same company in New Jersey that makes our snowy owl transmitters, a place called Cellular Tracking Technology. They're called Blue Morpho. And they're solar-powered transmitters about the size of a grain of rice. that connect to the internet of things. So all of those Bluetooth enabled microwaves and refrigerators and thermostats and cars and cell phones that are, you know, billions of them out there in the landscape. As, for example, my friends in Alabama have done, you put one of these things on a hummingbird ,and you can follow it literally second to second as it's moving across the landscape. Now, we can't use those on owls because they're solar powered and they don't have a battery. So they only work for animals like hummingbirds that are active in the daytime. So there's all of these new technologies that are coming around. Some of them, there's pros and cons to each one. They're all complementary technologies. None of them are going to, you know, no one technology is going to replace everything else.  

I still band birds. I still put lightweight numbered leg bands on the legs of owls and other species. which are a simple, effective, cheap way of tracking bird migration. None of these new technologies are going to make bird banding obsolete, but they're adding such a richness to our understanding of these birds' lives. Like those snowy owl transmitters that we're putting out, they give us latitude, longitude, altitude, and flight speed as frequently as every six seconds. And then a couple of times a week, the transmitter dials up through a cell phone modem and sends us all of that information through the cell network. And so my standard joke is my friends are cooler than your friends because I get text messages from snowy owls. And then all of that tracking data that we get from Project Snowstorm goes up on our website. So, you know, if you're a Project Snowstorm supporter, you can see where the snowy owls that we're tracking are. Now, we're not going to tell you where the snowy owl is right this moment because we want to give the birds a little bit of a safety margin. So all of the tracking data is time delayed at least 24 hours. So there's a bit of a buffer there for the snowy owl.  

But yeah, it's just shown so many surprising things. I'm not even sure where to start with some of the surprises that we've gotten from it. For example, and the other cool thing is with MOTUS and by the way, it's spelled M-O-T-U-S. If folks go to MOTUS.org, that's the website for the MOTUS Wildlife Tracking System. All the tracking data from all of those tagged birds and bats and butterflies through MOTUS is again publicly available. And there's a map that shows all of the MOTUS stations in the world. And you can find the one closest to your home and click on it and see exactly what's been flying past that station and detect it. And then for each of those birds and bats and insects, you can get a map showing where that individual animal has gone. It is so freaking cool and highly addictive. I think you should only do that when you have a lot of time to waste. 

Cecily Hansen 

Yeah, it's great that information like that has become so accessible, especially like we here at Nature Up North, one of our most important goals is to connect people in St. Lawrence County with nature. And I think that technology has become so helpful for that, for like identifying different animals and plants. And then I know like with eBird, community members can be like a really big part of this like large scale data collection. I was wondering if you could talk a little bit about that, too. 

Scott Weidensaul 

Absolutely. I mean, eBird has been an absolute game changer for our understanding of Originally, it was sort of we were looking at like bird-like creation of bird movement, but now we've got such a rich, and I say we, you know, eBird is run by the Cornell Lab of Ornithology. I'm not affiliated with Cornell. I write for their magazine a few times, but I'm saying we sort of in the sense of the ornithological community have, you know, have such a rich data set now on things like population changes because eBird's been going on for so many years now, we've been able to see how populations of different birds in different parts of the country are rising or falling or remaining stable based on eBird data and at a really, really granular level. I mean, if folks go to eBird and look up what are known as the status and trend maps for like 648 species of North American birds, you can see down to the level of like a 27 by 27-kilometer pixel, how birds are doing at a hyper-local level. And in some cases, the news is good. 

 For example, Wood Thrushes, which are a species which, for the 35 or so years that I've been involved in bird conservation, have been sort of a poster child for a decline of eastern forest songbirds. Their populations were going down and down and down and down. They've turned around. Their populations in the last 10 or 15 years have started going up broadly across much of their range. except in the northeast where I live up here in like from basically eastern Pennsylvania up into New England and eastern Canada. Why? We don't yet know but there are big projects going on right now mining eBird data, using MOTUS movement data to figure out where these birds are going, what routes they're following, what stopover areas they're using. It's giving us actionable conservation information that we can take out in the field and, you know, and start to turn things around for these birds.  

In some cases, eBird is acting as a warning sign. I mean, if you look at the status and trend map for American Robins, you'll see that pretty much across the entirety of the robins range, their populations are in decline. Not really steep decline, but decline. And if a bird is common and widespread as robins are in trouble, that tells us something that we need to be paying attention to. 

Cecily Hansen 

So I know another way that community members can be involved in kind of like understanding bird migration is through tools like BirdCast using Doppler radar. Could you just talk a little bit about how that works? 

Scott Weidensaul 

This is another one of its completely addictive tools. And it's something else that has come out of the Cornell Lab of Ornithology, along with Colorado State University and UMass Amherst. So yeah, so there's this network of about 148 Doppler radar stations across the US, mostly at large metropolitan airports. And every time you turn on the weather forecast for your local forecast, they're probably going to show your local TV newscaster is going to show you what the local Doppler radar is showing. But Doppler radar can pick up a lot more than just, you know, rain and snow and sleet and hail. It can also pick up anything else in the atmosphere, including migratory birds. And because most birds migrate at night, even the ones that are normally active in the daytime, it's traditionally, it's been extremely difficult to study nocturnal bird migration. I mean, in the 1940s and 50s, people literally, scientists were literally sitting outside with telescopes trained on the disc of the full moon, counting the silhouettes of birds flying across the full moon. It's called moon watching.  

Well, now, We've got Doppler radar and enough computing power that ornithologists can in real time calculate how many birds per cubic meter of airspace are going over these Doppler radar stations. If you go to BirdCast, which is B-I-R-D-C-A-S-T dot I-N-F-O, it's a website that will tell you, like for example, if you plug in your county, will tell you during spring and fall migration exactly how many birds passed through the airspace of your county the night before. It will also give you migratory forecasts based on the weather, showing a map of the country and in, you know, where the highest and lowest areas of migration on the next three or four nights are going to be. For birders, it's a real game changer. But not only that, it will tell you based on eBird data what the most common migrants passing through your area at that particular time of the year are. And you can see night after night how the migration shifts, how the, you know, there are some species that migrate earlier than and later than others. And you can see. sort of the flavor of the migration changing as you go from the very earliest migrants in spring to the very latest migrants in fall.  

It's just, it's a really cool thing. And it will tell you at a continental scale how many birds migrated the previous night. And some nights we get as many, we get more than 1 billion birds moving across the lower 48, which again, if we could, man, if there were some way that we could show people in real time how many, you know, to see the birds flying overhead, it would be one of the greatest wildlife spectacles on the planet. But we're sitting inside our houses, streaming something on Netflix, largely unaware of this enormous wave of feathers that are passing, you know, over our silent houses in the night sky. 

Cecily Hansen 

Yeah. I actually was following BirdCast here in St. Lawrence County very closely this past spring migration. And I was just completely blown away when I woke up one morning and it said over 4 million birds had flown over St. Lawrence County last night. I was just like, I can't even believe it. 

Scott Weidensaul 

I know, it's mind blowing. But when you think about it, we've got, you know, an estimated 20 billion birds coming down out of the Canadian boreal forest every year on the fall migration. 'Cause of course, in the fall, you've got all the adult birds plus all the young, so the fall migration, the magnitude is even greater. Yeah, it really, it is extraordinary to think of the numbers. And again, just how few people really appreciate the enormity of that migration, that it's just flowing like a river over our heads. 

Cecily Hansen 

Yeah, I had no idea. Prior to this year, I had no clue there were so many birds flying at night. I just had no idea. 

Scott Weidensaul 

Well, I mean, and you're not the only one. That's one of the things I love about talking to people about bird migration is, you know, when you start talking about what birds are capable of doing, their eyes just tend to get bigger and bigger and bigger and bigger. And there have been times when I have been accused of making stuff up, and just for the record I am NOT making stuff up. I mean, it's all it's all grounded in science. Some of it sounds like science fiction, like the notion that birds can see the Earth's magnetic field using a form of quantum mechanics called quantum entanglement, you know it sounds bizarre and yet the science is increasingly clear that that's exactly what they're doing. You know, birds are capable of doing so much more than we ever thought they were. And I suspect that the deeper we look, the more our amazement is only going to grow. 

Cecily Hansen 

I would love to talk now a little bit about how birds can travel so far during migration and kind of like what physical adaptations they have that can enable this migration? 

Scott Weidensaul 

Well, and that's some of the stuff that sounds among the most unbelievable. So, yeah, so birds have an ability to kind of flip metabolic switches in their body, and they're probably doing it biochemically, although we don't really know how they do it. They will just suddenly flip a metabolic switch that allows them to start packing on fat, because that's the fuel that these birds are burning on their migration. There's a bird that passes back and forth through St. Lawrence County every year on its migration between South America and the Canadian boreal forest called the Blackpoll Warbler. And most Blackpoll Warblers take off from the northeastern coast in the fall and migrate out over the western Atlantic Ocean for about three or four days. taking off from as far north as like Nova Scotia and flying all the way down to the northeastern coast of South America. And they'll do that on like 12 grams of fat. So, I mean, they'll beat their wings like 4 million times. By one calculation, if they were burning gasoline instead of fat, they'd get set 120,000 miles to the gallon. I mean, just phenomenally, phenomenally efficient little engines.  

But you also have birds that will undergo some pretty significant physiological changes, like for example, a lot of our thrushes, like Hermit Thrushes and Grey-cheeked Thrushes and Swainson's Thrushes, especially those like Swainson and Grey-cheeked that migrate to Latin America, Wood Thrushes, their intestines will actually grow in the fall because they're feeding on these lipid-rich berries. They eat a lot of fruit at that time of the year, native fruits like viburnum and dogwood and spicebush. And so, you know, by increasing the mass of their intestines, they're squeezing as much caloric value from that as possible. 

But then you've got birds that go the other way. There's a bird called the Bar-tailed Godwit, which is a large shorebird that breeds, well, Bar-tailed Godwits breed across most of Eurasia, but there's a population that breeds in western and northern Alaska. And those Bar-tailed Godwits make the longest non-stop migration of any land bird on earth. They fly between, they fly about 8,100 miles non-stop across the widest part of the Pacific Ocean, basically from Alaska to New Zealand and the coast of Australia will take them anywhere from seven to 11 days of continuous powered flight. So to get ready for that, they gather up in late August and early September along the shores of the Alaskan Peninsula and they feed, they undergo something called hyperphagia, which is just basically binge feeding. They just eat and eat and eat and eat and eat and eat and eat and eat. And they essentially more than double their weight in about two weeks. So they are 55% fat by the time they're ready to migrate. So they've put on all this fat. They no longer need their digestive system, so they get rid of it. In a matter of days, their stomach and their intestines, and to a lesser extent, their kidneys and their liver, atrophy dramatically. So their guts get dramatically shorter at the same time that their pectoral muscles the chest muscles that power that in that days and days of flight increase by about 50% in mass and their heart muscle increases 30 to 50% in mass. 

 So they get ripped and buff without exercise. I would like to sign up for that deal. And in fact, there are human physiologists that are studying how birds do this because many birds, as they're coming into migratory condition, significantly increase their muscle mass. They also become essentially immune to the effects of sleep deprivation when they're in migration. We don't know how. I'm an owl bander. I would like to avoid the effects of sleep deprivation during the fall migration season when I'm staying up all night. You know, they're just their blood chemistry. When you look at the blood chemistry of a migratory bird about to take off, it's been described as similar to an obese diabetic with a heart condition. And yet they suffer no ill effects from that. Again, we would love to know why, because there are probably applications for human health that reside within the genes of these birds and the physiological changes that they're able to undergo. It's just an absolutely phenomenal thing. And this is where, that Bar-tailed Godwit thing. I mean, I've literally had people accuse me of making stuff up. But I swear, I know the guy, I know the two scientists that first discovered the fact that these birds are losing their, basically losing their guts. You know, it's an amazing thing. 

Cecily Hansen 

All right, Naturally Speaking listeners, this ends part one of my interview with Scott Weidensaul. Give Part 2 a listen to hear about some more adaptations birds have to enable migration, how climate change has impacted migratory birds, and what we can do to help. Don't forget, get up and get outdoors with Nature Up North. 

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