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Okay, but can birds predict the weather? · Okay, But... Birds

• 0:00
  Everyone has an uncle or something who had a joint replaced, right?
• 0:02
  And complains of joint pain when the storms get bad, right?
• 0:06
  Or the pressure changes.
• 0:31
  December 26th, 2004.
• 0:33
  An undersea earthquake triggers the Indian Ocean tsunami.
• 0:36
  But along much of the coast, people don't feel a thing.
• 0:39
  In Yala National Park, some elephants and other large animals start moving inland before the waves arrive.
• 0:44
  Afterward, there were surprisingly few large animal deaths compared to the devastation nearby.
• 0:49
  Elsewhere, there are smaller stranger moments.
• 0:52
  In Phuket, people later recall dogs refusing to walk.
• 0:55
  Along the coast, birds abandon the shore.
• 0:57
  Nothing dramatic enough to trigger an alarm at the time, just off.
• 1:01
  It's not a one-off.
• 1:02
  Before the 1975 Haichung earthquake, reports of unusual animal behavior alongside smaller foreshocks helped prompt an evacuation.
• 1:10
  And before the 2009 La Quila earthquake, researchers observed toads abandoning a breeding site days in advance.
• 1:16
  You don't have to go to a tsunami or earthquake to hear this kind of story, though.
• 1:19
  Cattle lying down in a field is supposed to mean rain is coming.
• 1:23
  Frogs going quiet at dusk is supposed to mean a shift in the weather.
• 1:26
  Bees disappearing into the hive in the middle of the afternoon, a barometer falling without anyone reading it.
• 1:31
  We've all heard some of these, maybe from our grandparents.
• 1:33
  Yeah.
• 1:34
  And I think a lot of us, when we hear this kind of folklore, do the modern adult thing where we shrug and say cute, but probably nothing.
• 1:40
  But pay attention to birds for long enough and a pattern actually does start to show up.
• 1:44
  We name birds after this.
• 1:45
  The yellow-billed cuckoo, for example,
• 1:50
  A long-tailed skulker that almost nobody sees has earned the nickname Rain Crow across the American Midwest and South.
• 1:56
  Some people call it the Storm Crow.
• 1:58
  Same bird, two folk names, both pointing at the same observation.
• 2:02
  This cuckoo has a habit of calling on hot, humid afternoons just before a thunderstorm rolls in.
• 2:06
  It will keep calling through the rain.
• 2:08
  People got tired of saying yellow-billed cuckoo, looked at what the bird was actually doing, and nicknamed it after the weather.
• 2:13
  It's a good thing.
• 2:14
  That's not nothing, that's centuries of careful watching.
• 2:16
  The question is whether the bird is actually doing anything weather related or whether we just enjoy the story.
• 2:21
  Which brings us to the topic of today's episode.
• 2:23
  Okay, but can birds predict the weather?
• 2:26
  To dive into this, we'll talk with Dr. Gunnar Kramer, an assistant professor in the Department of Natural Resource Ecology and Management at Iowa State University.
• 2:33
  Gunnar studies migration ecology, which means he spends a lot of time trying to figure out where small songbirds go when nobody is watching, how they decide when to leave, and what cues they're picking up out of an environment that, to a human standing in the same field, looks completely unremarkable.
• 2:49
  After the break, Gunner walks us through what tiny songbirds are actually doing when they decide to launch themselves across 500 miles of open ocean with no place to land.
• 2:57
  And the moment in his career when one of his birds appeared to do something that, if you squint at it from a certain angle, looks an awful lot like a prediction.
• 3:05
  Stay tuned.
• 3:12
  All right, welcome back, everyone.
• 3:13
  I'm really excited to have Gunnar with us today to talk all about whether birds can predict the weather.
• 3:17
  Thanks for joining us, Gunnar.
• 3:19
  Thanks, Scott.
• 3:19
  Happy to be here.
• 3:20
  Yeah, I thought we could start off, you know, my grandma always told me these stories about the way birds act in the context of the weather.
• 3:26
  And I think for centuries, people have said, you know, birds can really actually predict the weather.
• 3:31
  So what's the folklore about that actually getting right?
• 3:33
  And what isn't correct about it?
• 3:35
  Yeah, you know, in ancient Greece, folks like Aristotle recognized that the community of birds that he was seeing around him changed seasonally.
• 3:44
  So swallows were there in the summer, but absent during the winter.
• 3:49
  And there were new species of birds that came in and kind of replaced those birds.
• 3:53
  And so in an effort to try to understand or describe what was happening, he discovered,
• 3:59
  hypothesize that these birds either hibernated in lake beds or maybe transformed into these other species or changed shapes or something, right?
• 4:09
  And so we can think about, you know, for a long, long time, people have been using birds as kind of a marker of seasonal time, right, of the change of the seasons.
• 4:20
  And so there's even a line in the Iliad by Homer talking about,
• 4:26
  cranes, you know, shrieking down from the heavens as they flee to the world's end, right, to avoid the nasty winter weather, basically.
• 4:35
  And so for a long, long time, people have been watching how migratory birds move without fully understanding where they go or what's driving those decisions.
• 4:47
  And it's actually not until relatively recently that,
• 4:52
  with advancement of modern technology that we can actually start to track some of these birds and disentangle some of the relationships between birds and weather and seasonal migration.
• 5:07
  Yeah, those transmutation ideas are interesting.
• 5:09
  I think that's why it's called the barnacle goose because they thought in the winter...
• 5:14
  the geese became barnacles.
• 5:16
  And then in the summer, the barnacles turned back into geese, which obviously we know is not right now.
• 5:21
  But you're right that we can track birds better.
• 5:24
  And then I think we can move away from just having anecdotal evidence that birds are in some way, they're reacting to weather in a predictable way.
• 5:32
  Is saying birds can predict the weather just incorrect?
• 5:34
  Or is it correct?
• 5:36
  We just really don't.
• 5:37
  We still have more to figure out.
• 5:38
  I think they're not necessarily predicting the weather, is my sense and my view on it.
• 5:43
  I think kind of spirals into this question of like, well, should we just use birds instead of radar to predict these massive storms or hurricanes or tornadoes?
• 5:53
  And the answer is really no.
• 5:54
  Like humans are very, very good at forecasting weather and we have really significant technology and knowledge in that realm.
• 6:02
  What birds are doing, instead of just predicting the weather, is they're highly adapted biological sensors, basically.
• 6:09
  They have all of these abilities to sense the environment that's around them and respond in ways that are going to be or have in the past been adapted, right?
• 6:20
  They've evolved this capacity to react to inclement weather.
• 6:26
  Instead of predicting, what I really think they're doing is they're responding.
• 6:28
  And they're doing so in ways that are really quite...
• 6:32
  impressive to us humans who lack some of these same abilities, right?
• 6:35
  And so it looks really miraculous and impressive for this tiny, maybe like a nine gram warbler to choose the right date and time to, for example, jump across the Gulf of Mexico or change behavior in light of some major severe storm.
• 6:53
  But in reality, it's not that they're predicting, they're sensing and responding
• 7:01
  Everyone has an uncle or something, but a joint replaced, right?
• 7:04
  And complains of joint pain when the storms get bad, right?
• 7:08
  Or the pressure changes, right?
• 7:10
  And so, you know, there's truth to some of this as well in humans.
• 7:14
  It's just we don't have the same evolved sensors that some of these birds have.
• 7:22
  I mean, to us, it seems like a prediction because we don't have the senses to detect subtle pressure drops in the atmospheric pressure or the slight scent that might be released because of reduced pressure or whatever.
• 7:36
  Some of my friends get migraines when the pressure changes.
• 7:38
  And so they know when that's coming.
• 7:39
  Well, before I do, because I'm lucky enough not to have that happen.
• 7:43
  So yeah, just better attuned to detecting things.
• 7:45
  Well, in that sense, then, a lot of these migrants that are coming up from Central and South America now are crossing the Gulf of Mexico in kind of one flight, unless they happen to land on a ship or something like that.
• 7:57
  How does weather factor into that decision making for these birds in terms of whether they just go, like, when do they go for it?
• 8:05
  How do they know?
• 8:06
  So the idea and our ability to understand the movements of these small songbirds across these big migration barriers is relatively new.
• 8:19
  And we are still trying to understand how they are sensing their environment and what decisions they're making.
• 8:26
  But I did some research on...
• 8:28
  golden-winged and blue-winged warblers, a species that we're both very familiar with.
• 8:34
  And we were just trying to understand where these birds migrate.
• 8:39
  And we used these relatively rudimentary course tracking devices called light-level geolocators to track their movements.
• 8:48
  And light-level geolocators, just as a brief explanation.
• 8:52
  Tell us how they work, Gunnar, because they are weird.
• 8:55
  Yeah.
• 8:57
  They're very simple.
• 8:58
  Yeah.
• 8:58
  They work by recording the timing of sunrise and sunset.
• 9:03
  And based on those two events and the length of the day, we can get a pretty good estimate of geographic location.
• 9:13
  Because of the tilt of the Earth and the natural variation in day length that occurs because of that tilt.
• 9:19
  And so it's the same way that sailors navigated before compasses and GPS.
• 9:25
  What we can see is very clear signals of...
• 9:28
  shade-free periods that are atypical, except for when these birds are near the Gulf and crossing the Gulf of Mexico.
• 9:34
  So what that means is that these geolocators allow us to pick up on the day that these birds jump across the Gulf.
• 9:42
  So Brumivora, Golden-winged, and Blue-winged warblers are like many other songbirds.
• 9:47
  They primarily migrate at night.
• 9:49
  And so if you're
• 9:53
  which we're experiencing right now.
• 9:54
  There are probably birds across the Gulf of Mexico right now, which is kind of crazy to think about.
• 9:58
  Just on their way, right?
• 9:59
  Yeah.
• 10:00
  Yeah.
• 10:01
  That's a minimum of 500 miles or around 800 kilometers, I think, of a distance to travel.
• 10:07
  And these are terrestrial birds.
• 10:10
  They cannot land in the Gulf unless you mentioned earlier, if they're landing on the ship, which does happen, but is relatively infrequent.
• 10:18
  You should not predict that you're going to find a ship, certainly.
• 10:21
  You should not.
• 10:22
  Yeah.
• 10:23
  And in evolutionary history, right?
• 10:24
  There were not many shifts for these birds to fly by.
• 10:29
  You should just go.
• 10:29
  And so they lift off from their departure site in Mexico or Central America at night.
• 10:36
  And then they fly basically nonstop up to 18 to 24 hours.
• 10:41
  until they reach the southern coast of the United States in spring.
• 10:45
  And so this takes a long time.
• 10:48
  And so what we see in the light data is just this perfectly shade-free period with really clean sunrises and often sunsets.
• 10:55
  And it gives us this window into when these birds are moving.
• 10:58
  And so we use those data to try to understand what weather conditions or climate conditions influence these departure decisions.
• 11:07
  Because picking the wrong...
• 11:11
  time to fly across will have really significant consequences for a bird, right?
• 11:15
  Yeah.
• 11:16
  There's, like we said, there's nowhere to land, there's nowhere to rest.
• 11:20
  And so if you pick the wrong day and you hit a big storm out in the middle of the Gulf of Mexico, you are going to be in a fight for your life potentially, right?
• 11:30
  Yeah, probably eaten by a shark.
• 11:33
  Yeah, exactly.
• 11:34
  There has been a lot of work where they've found a lot of songbirds during migration in the stomachs of sharks, which really proves the point, I guess, that these birds are flying across the Gulf of Mexico.
• 11:46
  There's another line of evidence to support that these birds are crossing, and many don't make it.
• 11:49
  But what we find with Vermivora, these very small, they're 9 or 10 gram birds, which is the same.
• 11:56
  I had to look it up.
• 11:56
  It's like three or four pennies, if anyone knows what a penny is anymore.
• 12:00
  Yeah.
• 12:01
  Because we've both had these birds in our hands and I've never thought, well, I'm holding one of them like, oh, it weighs like four pennies.
• 12:08
  So it's like, it's a helpful thing to say, but also it doesn't compute even when you hold the birds.
• 12:13
  I don't know.
• 12:14
  But I also don't ever remember feeling the weight of a bird in my hand because there's almost none.
• 12:18
  So it doesn't make sense.
• 12:20
  Yeah.
• 12:21
  Back in 2013, we were among a small group of scientists who started deploying these tags on...
• 12:30
  birds that were 10 grams or less.
• 12:32
  And so these are most of your warblers.
• 12:34
  At the time, we were basically testing out this technology on a small subset of birds in a pilot study.
• 12:41
  And so we were studying gold-winged warblers in the Appalachian portion of their breeding distribution in Tennessee.
• 12:48
  And we put these tags out, and geolocators are archival.
• 12:52
  They're not like GPS.
• 12:54
  They don't transmit any data.
• 12:55
  Yeah.
• 12:56
  The bird has to accept the tag, which rides on its back like a little harness, a little backpack on a harness.
• 13:05
  It has to survive the breeding season, survive fall migration, survive the winter, survive spring migration, and then come back to that same area where you marked it the year before.
• 13:16
  And...
• 13:17
  be detected by you and captured by you in a net, right?
• 13:21
  And before you can get that geolocator and download the data and understand where that bird went.
• 13:26
  And so we deployed these tags in 2013, and then we went back to Tennessee in 2014, the spring of 2014, and we started looking for returning birds.
• 13:36
  And we started to see some birds coming back, and some of them had these geolocators.
• 13:39
  So we were very relieved.
• 13:41
  It seemed like these birds carried these tags, and it was all going to work.
• 13:44
  And then in late April...
• 13:47
  Just as most of the birds were filtering back and starting to establish territories, we'd actually caught a couple of birds and removed geolocators at that point.
• 13:55
  But this gigantic tornadic storm system developed in the central U.S. and it started like turning its way towards Tennessee.
• 14:06
  And we had blue skies.
• 14:08
  This is, again, this predictive idea, right?
• 14:10
  Yeah, yeah.
• 14:11
  It was blue skies in Tennessee and no leaves on the trees, no environmental shading.
• 14:18
  And we went out one morning and we couldn't find any of our birds.
• 14:24
  And so all the birds that we had recited, they were like gone, right?
• 14:27
  And that can happen early in a season, right?
• 14:29
  Birds are shuffling around, figuring out where they want to be on their territory.
• 14:33
  But we noticed that they were gone.
• 14:35
  And then...
• 14:36
  We got forced out of the field the next couple of days because this gigantic tornadic storm came through.
• 14:41
  It has its own, this storm has its own Wikipedia page, actually.
• 14:45
  It was pretty bad, yeah.
• 14:48
  I think it had 82 tornadoes that it spawned.
• 14:53
  It injured like 500 people and actually killed 35 people and caused over a billion dollars of damage.
• 14:59
  So a very, very significant storm.
• 15:03
  Mm-hmm.
• 15:04
  And so after the storm passed, we went back to the field sites.
• 15:07
  We didn't know what we would expect.
• 15:08
  We didn't get hit with a tornado in our field site, but there were tornadoes around in the region.
• 15:14
  And we went back and we started seeing our birds again and recapturing them.
• 15:20
  And as we looked at the data...
• 15:22
  we noticed what appeared to be movement of these birds away from the breeding site in, in concordance or in, you know, coincident with this storm system coming through and ahead of it by a few days.
• 15:34
  Yeah.
• 15:35
  And so by a few days, by a few days.
• 15:37
  Okay.
• 15:38
  Cool.
• 15:38
  And so we looked at weather data as we would, um,
• 15:43
  We looked at pressure.
• 15:44
  We looked at cloud cover.
• 15:45
  We looked at temperature.
• 15:47
  And these birds initiated these movements well before any of the conditions changed relative to the storm at the site in Tennessee.
• 15:58
  And about these movements, like these birds moved...
• 16:01
  hundreds of kilometers, we think.
• 16:03
  And geolocators are not terribly precise.
• 16:05
  They have error with them inherent with this rudimentary technology.
• 16:09
  But we think that these birds moved 500 to 800 kilometers in some cases.
• 16:16
  Wow.
• 16:16
  Yeah.
• 16:17
  Returning along the routes which they came north.
• 16:20
  And they did so in ways that were pretty compelling.
• 16:23
  Like these tags are recording light, right?
• 16:26
  And so sunrise happens at a certain time, right?
• 16:29
  And so...
• 16:31
  when you have a tag on a bird that collects a sunrise 30 minutes earlier, you know, that's hard to explain without suggesting that that bird moved east and was experiencing sunrise on the globe earlier than our field site.
• 16:49
  And so we...
• 16:51
  thought about this a lot and did a lot of research into some of these sensory mechanisms.
• 16:57
  And what we kind of settled on as a likely hypothesis is that these golden-winged warblers
• 17:06
  sensed really low frequency noises or infrasound.
• 17:10
  So below our level of hearing, these are naturally occurring sounds created by ocean currents mashing against continental plates, you know, like a
• 17:24
  giant air masses sliding through mountain ranges produce these very low frequency noises that we as humans can't hear, but we know animals can hear.
• 17:34
  And so there's, there's evidence of, of dinosaurs probably could hear infrasound.
• 17:40
  And so, and we know that other birds can hear infrasound as well.
• 17:44
  So we think that this infrasound is relatively stable, um,
• 17:50
  geographically, at least natural sources of it, are kind of stable.
• 17:54
  And it forms this infrasonic map that birds might be able to use to navigate basically by
• 18:02
  hearing how close they are to some of these big sources of noise and positioning themselves in a place where they, you know, know that they use it as a benchmark basically to say like, okay, I want to be this far from this low frequency noise.
• 18:18
  And so what we know about these big tornadic storms of this severity is that, again,
• 18:25
  these hot and cold air masses as they're sliding over each other are producing low frequency noises.
• 18:32
  It's possible that these birds heard these noises and made the decision based on this time of the year.
• 18:39
  They didn't have nests.
• 18:40
  They didn't have yawn.
• 18:41
  They had just kind of got to the breeding site.
• 18:43
  They made the choice to evacuate and kind of get out of the way.
• 18:48
  Yeah.
• 18:48
  Yeah, it's an exciting time to be doing this kind of research.
• 18:51
  And that was a fun study and was one of those serendipitous things that you don't, we didn't set out to discover that.
• 18:58
  We were just literally, you know, trying to understand where these tiny birds go during the winter.
• 19:03
  That's what we were trying to figure out.
• 19:04
  And in the process, we learned something about that.
• 19:09
  how they respond in real time to severe weather.
• 19:12
  Yeah.
• 19:13
  And I think that's so often the case that you're planning on doing one thing and then something happens and you get to really think deeply about something else.
• 19:23
  And yeah, that's just how science operates.
• 19:26
  the infrasound idea is really cool.
• 19:28
  I mean, there's good evidence, I think, that elephants use infrasound to detect where, like on the African Serengeti, where is it raining and then moving towards that.
• 19:39
  So it's not super far-fetched to suspect that they have this ability.
• 19:44
  And like you said, it's been shown in other birds.
• 19:47
  But man, yeah.
• 19:49
  having that kind of early warning system is pretty incredible.
• 19:53
  And it's cool that you guys just randomly captured the event.
• 20:01
  You know, with the gulls flying out before a storm approaches or, you know, rain crows or yellow-billed cuckoos, right?
• 20:08
  They start to sing right before rain events.
• 20:12
  And most of those are associated with pressure changes.
• 20:15
  Can you speak a bit to that atmospheric pressure piece in all of this?
• 20:19
  Yeah, so this is, and I'm not a sensory biologist, so I'm not an expert in this exactly, but my understanding is that we're still trying to figure out exactly how these birds are sensing some of these cues.
• 20:33
  But as far as pressure goes, I think the leading idea is that these birds have a membrane in their ear, a tympanic membrane of sorts that is sensitive to,
• 20:43
  to these changes in pressure.
• 20:45
  But one of the other competing hypotheses is that birds don't have regular lungs like us humans, they have all these air sacs.
• 20:51
  And so they are constantly taking in this air and it's filling cavities in their body in a different way than it does in mammals and humans.
• 21:01
  And so there's potential for
• 21:04
  birds to sense changes in that atmospheric pressure in multiple avenues.
• 21:10
  And so whether it's this tympanic membrane in their ear or an air sac or some combination of those factors, we think it's something to do with those, but...
• 21:22
  I mean, the air sac idea I had never heard of before.
• 21:24
  For people listening, they're probably like, air sacs?
• 21:26
  What are you talking about?
• 21:27
  So it's hard to explain and probably the thing that confuses my ornithology students the most, but birds have one directional flow of air through their lungs.
• 21:36
  So we have these blind sacs we breathe into, they expand, we breathe out, it's the same bolus of air.
• 21:42
  But for a bird to...
• 21:44
  exhale air, it actually breathes in twice before that comes out.
• 21:48
  As the air goes into their bodies, like Gunnar's saying, it fills these air sacs and they're all over their body.
• 21:53
  So yeah, if there were sensors really, I mean, I guess thinking back to the uncle with the broken, you know, healed foot, if you have these pressure sensing sacs all over your body, it makes intuitive sense that it might allow you to detect really subtle changes in air pressure.
• 22:07
  I just never heard that.
• 22:08
  Yeah.
• 22:12
  One of the most amazing experiences I had was spending a spring banding returning migrants on the Gulf Coast of Texas.
• 22:21
  Okay.
• 22:21
  And so we were like on a barrier island, basically, or we were right up against the ocean.
• 22:27
  Mm-hmm.
• 22:28
  capturing birds in mist nets to determine... We were just banding them and looking at condition of birds that were coming through, how much fat they had, how much fuel stores, and looking at species composition and abundance of individuals.
• 22:41
  And we had what birders and ornithologists refer to as a fallout day, where basically these birds took off from Mexico the night before,
• 22:54
  under presumably decent conditions.
• 22:55
  And they hit some weather halfway through, and specifically like a little bit of rain and a north wind, right?
• 23:02
  Which is they're flying north and they're facing a headwind and that becomes energetically demanding.
• 23:08
  They'll stop migrating and land at the first available stopover site that they can find, which is often coastal islands.
• 23:16
  And so we kind of suspected that this was happening and we went out in the afternoon.
• 23:22
  We were watching...
• 23:24
  and hearing these birds falling out of the sky.
• 23:27
  And it was one of the most remarkable things.
• 23:29
  I've never seen anything like it since.
• 23:31
  But it was almost as though birds were whizzing by you at super fast speeds.
• 23:37
  And if you think about the shape of a peregrine falcon, when they have their wings kind of tucked in, and this super aerodynamic thing, that's what these little songbirds were doing.
• 23:45
  And they were making this noise that I'll never forget of just like a
• 23:48
  you know, a whizzing bayou.
• 23:50
  And all of a sudden, then you'd look in the shrub and there would be an eastern kingbird
• 23:57
  or Baltimore Oriole.
• 23:59
  And so you got the sense that these birds were making this decision to stop migrating.
• 24:03
  And we went out the next morning and we started banding.
• 24:05
  We opened our nets and we caught like a ton of birds.
• 24:08
  It was like three nets open or four nets open.
• 24:11
  And we caught like 300 birds over the course this morning, all different species.
• 24:15
  And what struck me as really, really amazing is that all of these tiny birds, Tennessee warblers,
• 24:25
  Nashville warblers, golden-winged warblers, cerulean warblers, they had fallen out of this migration and fallen out and come down to earth.
• 24:36
  But they all still had all of these fat reserves still on their body.
• 24:41
  And you can blow away their feathers on their breasts and you can kind of see this subdermal fat that they store and use for fueling their migration.
• 24:50
  Mm-hmm.
• 24:51
  But they weren't in bad condition.
• 24:52
  And so what it meant to me was that these birds only stopped migrating because they didn't want to keep flying into this bad weather.
• 25:01
  But they're not on the knife's edge, right?
• 25:04
  They're not operating on the edge of their physiological capacity.
• 25:08
  And we know this actually from some modeling work.
• 25:11
  Like the Gulf of Mexico, we think that with the full fuel load...
• 25:16
  many of these very small warblers could actually make that trip four or five times without stopping.
• 25:24
  And so it's hard for us to imagine as people, as humans who have no flight capacity.
• 25:29
  And, you know, I can't even imagine running a marathon.
• 25:34
  And yet they're out there, these birds are out there flying 800 kilometers nonstop.
• 25:38
  And they got...
• 25:39
  enough fuel in the tank where they could just keep going and keep going, but they choose not to because they'd rather not burn that fuel and they'd rather save it for a day when they can, uh, you know, make some, make some distance and get back up to the breeding grounds.
• 25:53
  But it was really remarkable and, um, a really cool experience to see.
• 25:58
  And, and the other thing I'll just comment on is like the diversity of species that were in that fallout, you know, it was small warblers, it was cuckoos, uh,
• 26:08
  Ictorids like Baltimore Orioles and catbirds.
• 26:13
  So what's cool is that these are distantly related species, right?
• 26:18
  But this behavior, the migrating across this gigantic barrier has evolved many, many times.
• 26:24
  And therefore, it must be this really adaptive thing.
• 26:27
  Yeah.
• 26:28
  And like you're pointing out, these birds, if they didn't hit weather as they were going across the Gulf of Mexico, they probably would have flown another 800 or more kilometers before they decided to stop.
• 26:39
  And we've cooked up stories.
• 26:42
  I mean, when I was a kid, someone told me that ruby-throated hummingbirds travel across the Gulf of Mexico on the back of a Canada goose, which actually makes no sense because there's no Canada geese that are flying across the
• 26:53
  The Gulf of Mexico, as I'm aware.
• 26:55
  But actually, these tiny birds are well adapted to making these long distance flights that, like you said, the Gulf of Mexico isn't even really one of the longest.
• 27:04
  Right.
• 27:04
  But yeah, that's cool.
• 27:06
  It would be so cool.
• 27:06
  I've seen Fallout as well.
• 27:09
  And it is overwhelming when all these birds are around.
• 27:12
  It's like what a birder hopes for.
• 27:13
  It's funny that a birder is hoping for a messed up migration where the birds don't get to fly as far as they want at night, but it is pretty cool to experience.
• 27:23
  So...
• 27:24
  You know, this tornadic storm that you're talking about, it's not necessarily related to climate change, but maybe.
• 27:29
  But in general, we're seeing like the intensification of storms, especially at certain times of the year, that things, maybe these pressure systems or even infrasound might be more disrupted.
• 27:41
  What does that mean for, you know, we're talking about these birds, like you just said, all of these birds are using similar cues.
• 27:47
  They're migrating across the Gulf of Mexico together.
• 27:49
  What do you think all this...
• 27:51
  increased or what seems to be increased variation and the cues they might be using is going to do to them or is do we already know if it's causing problems?
• 28:00
  You know, I think all of that is really complicated, right?
• 28:07
  So it's hard to know exactly how birds are going to respond.
• 28:12
  And like I said, we've only been studying migration.
• 28:15
  We've only been able to get individual-based migration tracks for birds, small birds, relatively recently.
• 28:22
  And so...
• 28:23
  In the context of what birds can do or what they experience and how they react, it's very hard to know at this stage how climate change or changing frequency of severe storms is going to impact micromanage.
• 28:39
  But we know that future conditions, climate conditions, are probably going to be warmer and have more severe storms, right?
• 28:49
  There's more moisture, and a warmer atmosphere can hold more moisture.
• 28:52
  And so one of the things that influences birds' decisions to, like, cross the Gulf of Mexico is relative humidity.
• 28:59
  It factors in.
• 29:00
  And we don't know exactly why necessarily, but changes in humidity, any of these small things could have really big downstream effects on the timing.
• 29:15
  I think it's generally thought we've figured a lot of stuff out about why birds do what they do.
• 29:19
  But as you're pointing out, we've only been able to track these individual migrations of small songbirds for like two decades-ish.
• 29:26
  And so there still is a lot to learn both about
• 29:29
  how variable those are, and then also how them might respond to these broader scale changes that we're documenting.
• 29:34
  And one thing that's kind of repeatedly come up is, you know, birds are adaptable.
• 29:39
  They can fly, they can change their behavior.
• 29:42
  They've got a big toolbox for dealing with change.
• 29:46
  But
• 29:47
  I think it's this idea that the speed with which those changes are happening or the magnitude of those changes or their frequency with which things are out of the norm might be the challenging piece.
• 29:59
  Certainly, that seems to be the case with things like large El Nino events that if they come too frequently, there's no recovery piece or whatever.
• 30:06
  So, yeah.
• 30:08
  Right.
• 30:09
  We've reached the part of the show we call That's BS or That's Bird Stuff, where we give our guests an opportunity to debunk a myth that ruffles their feathers.
• 30:15
  So, Gunnar, what do you want to call BS on?
• 30:19
  I want to call BS on the notion that we have this whole bird migration thing figured out and that we know everything that there is to know about the movements and behaviors of especially smaller songbirds.
• 30:34
  And I think...
• 30:37
  You know, a lot of my work is to fill really critical basic knowledge gaps.
• 30:42
  So, you know, I'm not, I'm a movement ecologist.
• 30:45
  Maybe I'm a migration ecologist.
• 30:47
  I'm interested in what we call the full annual cycle of birds.
• 30:50
  But most of what I do is geared towards illuminating previously unknown birds.
• 30:57
  you know, aspects of bird biology to better inform our ability to develop conservation strategies.
• 31:04
  And so, so, you know, all of that work that we've talked about with golden-winged warbler migration was all just fueled by a very simple question, which was where do birds in Minnesota winter versus birds in Tennessee winter?
• 31:16
  And, and, you know, for, it may be surprising to people to hear that, you know,
• 31:23
  we don't know where individual populations kind of migrate to, right?
• 31:30
  We know the broad general range of birds or the distribution of golden-winged warblers or Baltimore Orioles or wood thrush on the breeding and non-breeding grounds.
• 31:41
  But,
• 31:42
  where those individuals from different populations are actually connecting to and whether they mix or not has really significant implications for conservation.
• 31:52
  And that's where a lot of my research comes in.
• 31:54
  And along the way, we learn all of these really cool things about how birds sense weather, how they might respond to different conditions.
• 32:02
  We've got a lot more to figure out.
• 32:05
  And there's a lot of species where we don't have any information.
• 32:08
  And I mean, yeah, your work linked to like these goldenwing warbler populations actually do winter in really different places.
• 32:14
  And it matters a lot for, like if you look at population trends in Tennessee versus Minnesota, one of those populations has declined a lot more than the other.
• 32:23
  And that population in Tennessee, mostly overwinters, is it in Venezuela predominantly?
• 32:28
  Yeah.
• 32:28
  Yep.
• 32:29
  Eastern Columbia and Venezuela.
• 32:31
  Yep.
• 32:32
  And so if you're thinking about, I think a lot of us think about conservation in the context of home and what we can do here.
• 32:37
  But for a lot of our migratory birds, they're only here for the minority of their lives.
• 32:41
  And so knowing where they go and working with partner countries to understand how we can conserve their overwintering populations is critically important to still having some of these species come back to our forests every summer.
• 32:55
  All right.
• 32:55
  Well, thanks so much for joining us, Gunnar.
• 32:57
  It's been really great to talk to you about the ability of these birds to undergo migrations in the context of the weather they're experiencing.
• 33:03
  And yeah, thanks for taking the time.
• 33:05
  Thanks, Scott.
• 33:10
  Birds are dinosaurs and around here we like our snacks, so we end each episode with a dinosaur nugget.
• 33:14
  Today's nugget is, birds aren't really predicting the weather, they're sensing it with senses we don't have and that we're still trying to understand.
• 33:21
  They can read drops in barometric pressure that humans don't notice.
• 33:24
  They almost certainly hear infrasound, the very low frequency rumble that big storms generate hundreds of miles away, well before the wind ever picks up.
• 33:32
  And they can see polarized light, which means they can read parts of the sky that look completely blank to us.
• 33:37
  So when grandma said the birds were acting funny before the storm, grandma was right.
• 33:40
  The birds were ahead of her and she was smart enough to be paying attention.
• 33:44
  That's a wrap on this week's episode.
• 33:45
  Okay, but can birds predict the weather?
• 33:48
  If you like this episode, leave us a rating or review or like and subscribe.
• 33:51
  We'll catch you next time.
• 33:52
  Bye.
• 33:57
  Okay, but birds is hosted by Scott Taylor with production and creative by Zach Carl.