Science Friday - Feather Communication, Thermal Imaging Wildfires, Tick Saliva. September 25, 2020, Part 2

Episode Date: September 25, 2020

Thermal Imaging Technology Helps Firefighters See Through Smoke Wildfires are still raging out west, and states are using anything in their arsenals to fight back. This year, for the first time, Oregon’s Department of Forestry is using thermal imaging technology to see through thick smoke to the fires below. The state’s firefighting teams say this technology has been game-changing during this devastating wildfire season.  Thermal imaging technology uses infrared waves to detect heat, and then presents that information visually. These graphics make it possible to see exactly where the fire is moving, which areas are the hottest, and how much is actually burning. This information is crucial to firefighting teams on the ground, who can know with more certainty which areas are safe to enter. Freelance tech reporter Kate Kaye from Portland, Oregon joins Ira to talk about seeing this tech in action in a plane several miles above the wildfires.  Birds Of A Feather Flutter Together Bird feathers have many different functions. Softer down keeps a bird warm and stiffer wing feathers are used for flight. Feathers are also important in communication. Bright plumage can say ‘hey, look at me.’ And some birds even use the shape of their feathers as a communication tool—by using the sound their feathers make to relay messages. The results were published this week in the journal Integrative and Comparative Biology. Biologists Valentina Gomez-Bahamón and Christopher Clark, both authors on that study, describe how birds might develop different wing-fluttering dialects, and how this could play a role in the evolution of bird species. Check out more sounds, videos and images from the research! To Milk A Tick  Ticks are masters of breaking down the defenses of their host organism to get a blood meal. They use anesthetics to numb the skin, anticoagulants to keep the blood flowing, and keep the host’s immune system from recognizing them as invaders and kicking them out. And the key to understanding this is in the tick’s saliva. Biochemist and microbiologist Seemay Chou discusses how she milks the saliva from ticks to study what compounds play key parts in these chemical tricks. She also talks about how ticks are able to control the microbes in their saliva.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Iroflato. Wildfires are still raging out west and states are using whatever is in their arsenals to fight back. Case in point, this year for the first time, Oregon's Department of Forestry is using thermal imaging to see through the thick smoke from fires. Firefighting teams say this tech is a game changer during this devastating wildfire season. Joining me to talk about this is Kate Kay, freelance. tech journalist based in Portland, Oregon. Welcome to Science Friday. Thanks, Ira. So tell us, how are things in your neck of the woods in terms of wildfires right now? Well, my neck of the woods has not been touched. I live in Multnomah County in Portland, but very close to here. In the Mount Hood

National Forest, in the Cascades Mountain Range, all to the east and south. There's wildfires still raging throughout the state, really. And you had the opportunity. as I understand it, to go up in a plane above the Oregon wildfires to see how the Oregon Department of Forestry is using thermal imaging. Tell us what that experience is like and what you saw up there. Well, when I first had the opportunity, you know, I was envisioning going up in a plane and seeing down and looking down at fires. You know, in reality, you're not looking down at anything. You're seeing thick smoke out the window of a, you know, small aircraft. So the best way to describe it would be flying through potato soup.

I mean, that's what it looked like. We were up through several hundred feet of very thick smoke. There's so many wildfires burning and they're converging that it's just creating even more smoke than ever right now. So the thing that I was there to see, though, is inside the plane, they have this thermal imaging technology that is actually detecting. the heat of the fires below. So it's visualizing that on a monitor on a screen like our computer screen in the plane and showing like a heat map, the heat signatures of the fires below.

Hmm. So they're actually getting thermal images coming in and it gets translated into pictures that they look out like as hotspots on a screen. Yes. So what kind of information then, are you able see using this thermal imaging that you can't see otherwise? Well, I mean, they're visualizing it. It looks like a grayscale image that shows kind of a glow of, you know, anywhere where there's heat that's being detected, changes in heat signature that's being detected. They can get the exact lat-long coordinates of where this heat from the flames is being detected and from where the radiant heat is being detected.

And from a information standpoint, they can actually layer in this information that they're gathering through this infrared technology onto a topographical map after the fact. Or even in real time, they can, in some cases, the dispatch centers throughout the state are able to obtain this information in real time as somebody is up in an aircraft flying over where they're. the new fires might be spotted or where a shift in fire is spotted, they can take video or show, hey, I'm over this area right now. And then they could look at a topographical layer and it would show that it's burning along a hillside and that it's near where homes are, for example. So there's a lot of interesting data that can come out of it. So they can actually see where the fire is moving and what parts of the fire are the hottest? Yeah. So when I was up there, we were up above one of the more massive fires that's burning right now. It's the beachy creek fire. It's essentially

in the Mount Hood area to the east of Salem and Portland. So I was up there with a aircraft operator from Oregon Department of Forestry. And he was looking over an area that he had done the same thing about flying above before that, the day or two before that. He was trying to distinguish what's changed. How is this fire, you know, shifted? You know, that information can be used to determine how to deploy resources on the ground. And you'll have a clip with that gentleman for us right now, too, right? Yeah. So he, his name is Cole Lindsay. He is an Oregon Department of forestry multi-mission aircraft operator. And he talks a little bit about why this is, you know, helpful.

I get feedback from the people, the operations people, and tactical people about what they saw, what they need to see. And so from my end, I feel confident that this is being very beneficial in helping them make a lot of decisions on the ground, especially because nobody else can see through the smoke right now. it makes it extra, extra beneficial that we can be in this aircraft seeing this thermal image. That's interesting. Can you tell us how specifically does this thermal imaging technology help fight the fire? Well, I can tell you how it works a little bit more. So it's actually using

shortwave infrared technology that, again, it detects changes in temperature and then it visualizes that data in a way that the human eye can see it. There's a really interesting aspect of this technology. It uses an algorithmic local area processor. And what that does is it visualizes the variations in temperature. So it actually can distinguish between the heat that's directly from a flame or the flames of a fire and the radiant heat. So if you're looking at this visual image, you can actually see. Actually, the fire itself is like this amount of surface area, whereas the glow is a lot more.

And there's actually a really interesting clip from Marshall Gross, who's a manager of the company that makes this technology fleer. They're actually based here in Oregon. And he's in their applications engineering group, and he describes that. You see the glow of the fire on the ground, and it looks, you know, so big. When you use this localery processor, it will actually identify within that glow, where is the hottest point? Right. So they can see kind of how much is actual probably fire burning and the rest of that's radiated heat from that fire.

Oh, that's interesting. Okay, so you have all this thermal imaging up there in the plane. How can the folks on the ground, the fire crews on the ground, use this information? Yeah, so they have, when we flew out of Salem, we actually were in a small aircraft hangar in the Salem airport where the Oregon Department of Forestry is kind of hold up. They have this makeshift command center in there with this whiteboard with all this information showing all of the aircraft resources that they have that are being deployed right now. And then they have multiple software systems.

These systems are able to talk to each other so they can feed in video. from this thermal imaging technology, they can take videos and images from the software and then store it for later and use it, you know, and incorporate it with the other kinds of information that they have. Like I said, topographical maps, where their systems are deployed, where resources are deployed. It can even be used by federal agencies, too. So it's kind of, I think one of the things that's happening that's interesting is that there's just more data sharing that's taking place. So it's not just that this thing's working like in a vacuum by itself. It's working in conjunction with a lot of other technologies that are helping give them more information than they've

ever had. So even though you're in Oregon and they're using it in the Oregon fires, there's no reason why you couldn't use it on the California fires too. Right. So as I understand it, it is being, or at least it has been used in California, there's several fire agencies in that state that have used this thermal imaging technology to fight the wildfires. I understand there's a good chance. We'll see more of this thermal imaging technology in our lives due to COVID. Yeah, it's really interesting. The only reason I even knew about this company, Fleers, because they sell systems that are kind of based on the same thermal imaging, but what they do is they their body temperature scanning devices.

So you might have heard about these things in airports or transit hubs or even in workplaces. I mean, Amazon uses this kind of technology in shipping distribution centers, for example. And the idea is to detect elevated body temperature of people. And in a way, understand, hey, this person might have a fever, which is an indicator of COVID-19. They've used this kind of technology, though, in the past with the SARS epidemic and the Ebola outbreak. So it's definitely something that's actually been deployed all over the world in various places where there's large, usually where there's large groups of people moving. Yeah, you've got to be really good, sensitive enough, I would imagine, to be able to detect the difference in someone's body temperature from, say, 98 and just 2 degrees to 100 degrees. in a body. There's a lot of, I think, skepticism around the accuracy of that kind of technology,

especially when it's used for like a group of people. It can be used in a way that's a lot more precise and like, you know, they'll have a handheld temperature scanning device that is held up right to actually measures the heat from your tear duct. Wow, your tear duct. Apparently the hottest, where warmest part of the body is in your tear duct. And so that's what they're measuring when they have these handheld scanners, at least the company Fleer. That's how their system works. So to me, one of the really interesting questions about all this stuff is kind of the ethical questions around it. Not just are we okay with having our, you know, when we go to a subway station or a train station or work having our temperatures scanned all the time, but also the fact that

the technology that's used for the wildfires, it's also used for more controversial things, like law enforcement purposes. It's used for border security and surveillance. So I think it's really interesting to think about that sometimes, you know, technology, it might have a lot of valuable beneficial purposes that a lot of people don't question the value of. But then there's sometimes some other ethical questions that we need to at least recognize that these technologies are used for all sorts of reasons. Yeah, Kate Kay, thank you very much for taking time to talk with us. Fascinating stuff. Thanks, Ira. Kate Kay, a freelance tech journalist based in Portland, Oregon. We're going to take a break, and when we come back, a look at how birds communicate using the sound of their

fluttering feathers. Wow, we'll be right back after this short break. Stay with us. This is Science Friday. I'm Iroflato. A little heads up for you, bird nerds. The shortened daylight hours and drop in temperatures are all signs of fall bird migration. So now is the time for you to spot hundreds of species flying overhead. And scientists estimate there are about 10,000 species of birds. But have you ever wondered what evolutionary processes led to the diversity in birds?

Details in bird feathers are providing clues to the answer. Producer Alexa Limb is on the case. Bird feathers have many different functions. There's the basics. Softer down keeps a bird warm and stiffer wing feathers are used for flight. And feathers are also important in communication.

Bright plumage can say, hey, look at me. and some birds, they even use the shape of their feathers as a communication tool by using the sounds their feathers make to relay messages. A team of scientists wanted to investigate how birds might develop different wing-fluttering dialects and how this could play a role in the evolution of bird species. Their results were published this week in the journal Integrative and Comparative Biology. My next guess are both authors on that study. Valentina Gomez-Bamon is a PhD student in biology at the University of Illinois at

Chicago and a scientific affiliate at the Field Museum of Natural History. Christopher Clark is an assistant professor in biology at the University of California, Riverside. Welcome. Thank you. Pleasure to be here. Thank you. Thanks for inviting me and for your interest in our research. Sure.

Okay, so Valentina, I wanted to start with you. In the study, you looked at a bird called the fork-tailed flycatcher. What got you interested in this particular bird? Yeah, so it's a common bird in my home country. which is Colombia, especially in the Janus, which are flatlands towards the side of, the eastern side of Colombia. In these areas, there are times of the year where there are a lot of these birds, so clouds of furtale flycatchers moving around.

And then they leave and some remain, but, you know, it made me wonder, why are some leaving and why are some that stay here? Right. Yeah. And I mean, based on its name, it has a pretty distinctive tail. What does it look like? Yeah, it's a beautiful long tail that looks like a cister in Spanish people call them Tiheditas because it's like a, that's a name for Caesar. And I guess it's very descriptive of how they look like. And they also are very acrobatic. So it's not, you know, You see the tail sometimes opening sort of like a fan when they're catching insects. And they're also, they also fight with each other. So you can see them doing this, you know, flying almost upside down and turning around.

And so those flights are very, very interesting and beautiful. Okay. So there's two subspecies of this flycatcher that you talked about. One migrates and one doesn't migrate. So what question were you trying to answer in this study about that? Yeah, so they're actually four, but in this place where they coexist, when you can see them together, there's only these two subspecies. They look very similar. And the main difference that they have morphologically that you can distinguish when you have the two birds in your hand is the shape of the primary feathers.

And the question that I had was, well, first, you know, do they produce non-vocal sounds with their, their, their, wing feathers, and then do they defer because we know the shape is different? And this is only found in males. So because it's only found in males, one question was like, well, if they produce sound, is it something that it's produced during a particular behavior? Or is it just something that sounds because of the bird flying anytime? Right. And Chris, since you are a feather expert, can you kind of take us through some feather physics 101? How does a bird, feather make sound? Oh, there's a bunch of different ways that feathers can make sound. One of the mechanisms that's really common is that the feather flutters, and it flutters at a stable frequency

and gives off tonals out. And so it's kind of like a guitar string. When you have a guitar string and you pluck it, it vibrates at its resonant frequency. And so when a feather flutters, it's fairly similar to that. What happens is the air flows over the feather and that provides aerodynamic energy and then the feather starts to oscillate at a stable frequency set by its mass and stiffness one difference between feathers and a guitar string is that a guitar string is basically a one-dimensional object and so it has one primary resonance frequency that it will vibrate at feathers are flat they're basically two-dimensional but by having an additional dimension that means that there's many different ways that they can flutter so one particular feather might have

or three, or even sometimes more than that, different modes of vibration that it can express. And so what happens is that when a bird is flapping its wings, or in the case of some birds like snipe or hummingbirds, when the bird dives and spreads its tail feathers, by putting its feather out in the airflow while the air is going over pretty fast, that's what activates the feather

and enables it to vibrate at the stable frequency and make tonal sound. Wow. Are there certain spots or structures on a feather that are key for sound making? Usually, yes. The basic one is that the feather often has a modified shape. So, for example, in the feathers that Valentina studied, the outer wing feathers of the flight catcher, there's kind of a notch, maybe a centimeter or a centimeter and a half down from the tip of the feather. And everything distal to that notch, everything outside that notch, the feather is a little bit narrower than it would be otherwise. What that notch does, it separates the feather from its neighboring feather. So that means the feather is not overlapping with the neighbor. And it can flutter in that notched region. And then the other thing that often happens is that birds that make sounds by having their feathers flutter is that the feathers also change in stiffness. But the

stiffness differences are often really subtle and kind of it's in the microstructure. So it's really hard to see. Right. And Valentina, how did you see that the flycatchers were making these feather sounds? Like what context did you observe that they were using their feathers to make different sounds? Yeah. So one was when in the morning, these are some of the birds that wake up earlier in our study sites and they start singing and then I started you know hearing their their normal normal song and then I realized that at certain point they would stop singing and then fly like from from a perch to another perch and they would do a little sound that sounded like a like a song like and it was very clear um at least in the in the non-migrants and then also when they were fighting

So when they're fighting, they just do a lot of different displays. They show their crowns. They open their tails. They fly at each other. They call. They sing. And also they produce the feather sound. And I mean, qualitatively, I knew it was the feather sound because I had been following these birds for many years.

And I started to get to know them. But so then we had to actually make sure that the sound that's being produced is not vocal, but something that coincides with the motion of the bird flying. Right. Okay. So they were making these feather sounds while they were fighting and also for mating displays as well. No, I was going to say. So in this case, it's interesting because they are socially monogamous. So I think it's not necessarily a mating display, but more of a per bonding display because they produce the sound, you know, every morning during, yes, the breeding season, but they are already, they already have, you know, their nest and they're young. So it may be also

a per bonding display. So you recorded the sound of these two different subspecies of this flycatcher bird, one that migrates and one that doesn't migrate. I want to play a couple of these clips so we can get an idea of how different their bird flap sound. So this is the, First clip from the non-migrating species of the flycatcher. Okay, I want to play that one more time. Now, the second clip is from the migrating species of flycatcher. Okay, let's hear that one again. This first clip is the one labeled Monacus Liberation.

And the second clip is Savannah Liberation. Now, you can tell they do sound different. Yes, so Monaco's has one feather that is less notch. than Savannah. Savannah has three nudge feathers. And then something that we also notice on this study is that overall feather shape also differs between migrants and non-migrants. So migrant feathers are longer and narrower, they're thinner, whereas the non-migrants

have wider feathers and then they're shorter. And that potentially affects, you know, the part of the feather that vibrates. Right. Yeah, and can you talk about this a little bit more? You know, these feathers are definitely making a sound, but how do you know that the birds are using this for communication rather than just like a byproduct? Like, you know, humans clear their throats,

but that's not necessarily communicating anything. Yeah, so there's, so this type of sound evolves into communication sounds from incidental byproducts. So I like your throat clearing example. Or another one that I use a lot is the footsteps in humans. When you walk down a hall and you make footsteps, most of the time your footsteps, it's not intentional. You're not doing it to communicate with other people. It's simply a byproduct of walking.

And if somebody else happens to hear you, they can still know that you're there, but it's not necessarily for alerting them. But in people all the time, we modify our footsteps. You know, you might wear loud shoes or you might tiptoe. And when you do either of those things, you're then intentionally modifying how much sound you produce in order to try to affect whether or not other people detect. And so wearing loud shoes and walking down a hallway in loud shoes, that arguably is a signal. And so what happens in birds, a lot of the time when a bird evolves an originally incidental byproduct of locomotion and turns it into a communication sound, what they usually do is they usually evolve an instrument.

They evolve part of their feathers to actually be different in shape, and that difference in shape is tied to the sounds that they make. So that's what Valentina has with these notched feathers and the outer tips of the wings. It's the shape of the notch is unusual and distinctive. And in most cases, when birds have a notch like this in the wing feathers, they are then making relatively loud sounds with their wing feathers during a specific display. But it is the case that sometimes birds will make these sounds, these types of sounds, and there are no modifications.

So in humans, we clap our hands to applause. This is a type of non-vocal communication that we do all the time. And we don't have any special modifications to our hands for making applause. It's simply something that we do behaviorally. Right. Yeah. So is it that their sounds are different. And like you said, you know, they use them in these different contexts.

So then how does this push birds to speciate or become different species? Would they actually become unintelligible to each other? Yes. There are different ways in which animals and in this case birds can sort of be isolated in terms of reproduction. And so the first one is breeding in different places. And these birds also have shifted breeding seasons or schedules. So they don't coincide at the same time. The migrants, for instance, need to breed.

They need to migrate and they need to molt. And those three things don't happen at the same time, generally, because it's very energetically costly. So that's another way they're sort of like isolated. Then the other thing is they do differ also in tail length. So the tail of a migrant is shorter and in part because it has to fly really long distances efficiently. And we know that the tail is also used in this place. And then, you know, we know that the birds are together at some point of their life. So the question is, is there chances in which they recognize each other as different things or prefer each other as different things or do they actually mix?

And so we know they don't because we have data. from their genes, but it could be that in part is because they are understanding them as a different, each other as different things. So there's not only mate choice associated to this sound, but there's a preference to their own particular sound. We don't know that, but that would actually be, you know, a way in which we know that that speciation is reinforced. But from all this evidence, I think they are different species. It would be great to know, how much this primating isolation, which is the different sounds, actually influences their identity? If it's really something they discriminate or if it's just a byproduct that really doesn't make too much a difference,

just because there's these other reasons why they don't read. I'm Alexa Lim, and this is Science Friday from WNYC Studios. Yeah, that's interesting. So then how would you sum up how, I mean, what does this tell us about kind of speciation or evolution, the study? So for me, what's interesting is that we know there is a difference in ecology. Migrating and non-migrating are very two different strategies. And so being different strategies that affect, you know, how many eggs they lay, it affects their morphology, of course, because they're so much associated with flight. their schedules, how much they're going to eat, when they molt.

All these different things, these adaptations, and being in different environments and facing different situations, sort of like cascades many different changes associated to that behavior. And those changes sort of pushes the two lineages or these two groups into different morphological trajectories. And because these communication signals, are influenced by morphology, because it's the shape of the feather that influences, you know, how they're going to sound, then having that difference in morphological evolution may reinforce or just like bring more correlated differences

that sort of make these things different species, if that makes sense. That's what I think it's interesting. And the things that will affect how the bird communicates is the environment in which it's communicating, because the properties may be different of how the sounds moving in tropical versus non-tropical areas, or the light, for instance, when we're talking about plumage coloration or visual signals, and also the morphology associated to the bird's life or ecology. Right, yeah, that's amazing. And yeah, when you look at a bird or, you know, or you think about evolution, you look at these like big character characteristics you can see.

But, I mean, the study kind of shows that it's so much more fine-tuned. And like Valentina, you said there's so many cascading traits and effects that are going on that we can't see, but they're there. And you capture them. Yeah, and also because birds perceive the world differently. So we have to find a way in which we sort of like understand what they're seeing. They see more frames per second than we do. They see more colors than we do. And they probably hear differently than how we hear.

So it's important to have that in mind. And also to not think that at this place only one channel of communication, but that the birds are also moving while they're doing it. And just like in us while we're talking, we're also moving and saying things with our hands or our gestures. that may also be important in bird communication. Right. So the world is a little noisier and more colorful

than maybe humans can catch on to. Yeah. Thanks so much for joining us. Valentina Gomez-Bamon is a PhD student in biology at the University of Illinois at Chicago and a scientific affiliate at the Field Museum of Natural History. And Christopher Clark is an assistant professor in biology at the University of California Riverside.

Thanks so much. Our pleasure. Thank you. Thank you. For Science Friday, I'm Allexillin. We're going to take a break, and after the break, what does it mean to milk a tick? You'll want to know that answer, so stay with us. We'll be right back after this short break. This is Science Friday. I'm Iraflato.

Ticks are full of tricks, chemical tricks. They use anesthetics to numb your skin, inject anticoagulans to keep the blood flowing, They've also figured out a way to get around not only your immune system, but different types of host organisms. And did you know that they harbor microbes and somehow control these bacteria so that they don't get infected by the microbes? That's all kind of interesting stuff. And the key to understanding how these tiny creatures accomplish this is in their saliva. And this could be used for treatments for tick-related illnesses. And the next guest is what you might call a tick wrangler.

You can see photos of her tick-filled lab at ScienceFriiday.com slash ticks. CMA Chow, assistant professor of biochemistry and biophysics at the University of California in San Francisco. Welcome to Science Friday. Thanks for having me. I'm trying to figure out what a tick lab looks. Describe your laboratory. It actually looks a lot like any other lab. The only difference has what looks basically like a refrigerator of.

ticks inside and we wear white coats in there to make sure we can see them if they're on us. You know, I'd be afraid of them getting out. If they ever get out and, you know, feel something biting you? No, we've never had any get out. And I think the UCSF Safety Administration would also share that concern with you. But I have had a tick on me from elsewhere. Have you ever had one on you? Yes, I have. You know, I live in Connecticut. So we're, you know, the capital of Lyme disease. We're always careful about these. And the lime ticks really tiny. They're not like the bigger tick. Well, there's a couple of different life stages, so you probably saw one of the more juvenile stages on you.

And how did you get interested in studying ticks? I came about it through kind of a roundabout path. We were actually studying how bacteria compete with each other, completely independent of ticks. And we found that some of the toxins that they used to kill each other were basically stole. over the course of evolution by ticks and are now found in the genome of ticks. So we started probing how the ticks were using these antibacterials to try and kill off some of their own microbes. And then I got hooked.

Wow. So you're milking them, yeah. Yes, we're milking them as well. One of the things we found is that the antibacterial we are studying is really enriched in the saliva of ticks. And so we think that they're using this agent basically to kill off bacteria that they might encounter naturally when they're feeding. And so we just got deeper and deeper into the world of spit.

I love it. So if you figure out how they use, they can fight the bacteria off, then the logical extension is how we might be able to use our knowledge about that. Yeah, and I really think that's just the tip of the iceberg in terms of what we can learn from saliva, as you alluded to at the beginning, they do a lot of different things with their saliva because they're feeding on us for days to sometimes over a week. So they really have to figure out how to make a home and go undetected. I once interviewed a biologist who studied the spiders. And her job was to milk spiders for the venom. And she had a little YouTube video. You can't

you like what I'm talking about? Yes, I do. I think it's Binford was her name. I came from so long ago. And she applied a small voltage to the spider and got it to eject its. That's. Pretty awesome. And how do you do it? How do you milk the ticks? So it actually wasn't figured out by us. It was figured out by some researchers long ago, but we found this old paper. And you basically take the ticks and you feed them partially on an animal, a mouse in our case.

And then you can pull them off the mouse. And then we use very glamorous scotch tape to tape them down and then put a chemical called pylocarpine, which is used to enable both us and ticks to salivate. And then you put what looks like a little. glass straw on the feeding organ of the tick, and eventually you pull out quite a bit of saliva through capillary action. Wow. Okay. Let's talk about ticks in general.

Is there a mythology that people have? They think ticks do this, but they don't actually. Oh, I mean, I think the number one thing I run into is that people think ticks jump and fly, and they don't. They don't. No, no, they don't. They don't have the muscles in their legs to do that. So how do they get on you?

Yeah. So they do something called questing where when they're in feeding season, they basically climb to the tops of shrubs or grass, places where they may run into animals walking by. And then they are really adept at sensing our carbon dioxide, our body heat, other things that it would indicate that in animals nearby, and they raise their little legs up and latch on when you walk by. And it kind of looks like in the lab like they're reaching out, looking for a hug. Do they live in your grass, if you have a lawn? Are they living in the grass? Are they living in the shrubbery next to it? Yeah, I think it's context-dependent.

And in some parts of the U.S., they really like the grass. And in some parts of the U.S., they are more in the shrubs. I think it really is an indicator of whatever ecology they're surrounded by. Let's talk about you're interested in the saliva. Tell me what is so fascinating about the saliva. Yeah, I mean, I think studying the saliva actually gets. it's at one of the kind of creepiest things about ticks because the fact that you can have a tick on you and not even know it. I mean, I think that's why a lot of people are kind of both

fascinated and creeped out by ticks. But that is an indication that they've used their saliva to completely block your ability to sense it, block a lot of the alarm systems that are normally in place to help you detect them. So as you mentioned, your immune system, normally if you have some sort of mechanical wound, you would expect that there would be a raised bump or something, or itch and pain. These are all really annoying but useful things we have to help us know that something's there. And so we're really interested in mining what's in the saliva to try and understand these processes because ticks have basically hacked our system.

And if we can kind of use them as a muse to kind of follow what they figured out, we can have these clues to understand our own bodies more too. And then the second reason is that the microbes have really exploited this as well. We're sort of late to the game. The microbes use the ticks as vectors, meaning that they reside in the ticks and are able to be transmitted to their next host through the tick bite. And in fact, there's a phenomenon known as saliva activated transmission, which means that the microbe is enabled by the saliva. And without it, it would not actually be able to survive or spread in our body as effectively. So they've done these old experiments where they injected the Lyme pathogen Borreliaberg-Dorferi,

and without tick saliva, co-injected with it, your body's quite effective at clearing it. So somewhere along the line in evolutionary history of the tick, it picked up this method of disguise, so to speak? Yeah, presumably long ago. I think these are mechanisms that ticks didn't evolve on their own, but they've been, yeah, acquired and expanded. upon. Wow. So mosquito bites are not the same thing. Oh, ticks are way superior to mosquitoes for sure. Do they know that? Yeah, mosquitoes, you know, they don't make a home in us the way ticks do. As you know, they just need to be there long enough to bite and then fly off. Whereas ticks have to make this blood meal happen without it. They can't transition to the next life stage. Okay. So when I was a Boy Scout many, many years ago, there was always a chapter on.

on, you know, hiking and whatever. And what to do to prevent a tick, getting bitten by a tick, and once you get bitten, how to remove the tick. What, you know, we were taught either take a match, blow it out, the heat. If you put it on the head of the tick, it will back itself out. There was somebody who said you use vaseline or oil to cope the tick, it'll come back out. Any of that stuff, legitimate? I mean, honestly, the easiest way to do it is just take.

a pair of forceups and pull vertically, you've got to pull perpendicular to your skin. Straight up. You've got to pull hard enough that you kind of feel this like pop of it really releasing from your skin. Because its feeding organ is kind of has these spikes on it that dig into your skin. So you really got to break past that. So if you do it the wrong way, you can make things worse. You could squeeze it and you get more saliva injected in there? You know, I think mostly you just don't want the leftover residue of the tick debris in your skin.

You want to make sure that we were told got to get the head out. Exactly. Going to get the whole head out there or else you just really. Yeah. And as far as the small ticks, like the ticks that are tiny to see that we were trying to get out, you know, how do you look for them? Because they look like tiny little freckles on you. Yeah. Yeah, those are really, really hard.

A Lyme disease ticks. Yeah. Well, so there's actually three life stages. The ones that look like freckles are the youngest ones. They're the larvae. And those cannot transmit the Lyme pathogen to you because they have to acquire it from their first blood meal. And if they are feeding on you, you are their first blood meal. And so the ones you need to worry about are the next level up, which are more the size of like a large crack pepper or the adults, which you can clearly see.

But those, you know, really just paying attention after you go hiking or even for a few days after because sometimes pets can track them in. A hot shower after you go hiking can help. Having some lab mates look you up and down, fiddle through your hair. How did you decide? I asked you before you, but you just wake up one day and say, you know, I'm going to study ticks. Or did you come from a different insect? No, I had never worked with. And by the way, they're not insects.

Okay. They're arachnids. They're arachnids. But no, I had never worked with an arthropod in my life. I had never even seen a tick when we first found these genes in bacteria. So it was meant to be a very short fray into this area that I was just going to figure out what they were doing in ticks and move on. In my mind, it was like a six-month fray. Right.

Turned into a couple years of really learning about the biology of ticks and just the deeper you go, the more you want to learn. So that's basically how I started. And what thing mostly would you like to learn? What don't you know that you would like to know about ticks, how they spread disease, maybe there's saliva? Yeah. I mean, I think, you know, one of the things that my lab is really interested in that extends beyond just the people that are working on ticks is we're interested in understanding why bacteria have such specific associations with different hosts. And so ticks are a great system to study that because the pathogens that they carry are restricted to. to only a few species per pathogen.

And so there's this phenomenon called vector competence where we have these really unique and limited relationships between one pathogen and one or two or a few different tick species, even though there's a lot of other tick species that can encounter it. And this is true. Beyond ticks, it's also true for mosquitoes and fly vectors. But, I mean, even beyond that, just animals. Animals. How they associate with microbes.

So this is one way that we can study this problem by looking at, why it is this bacterium is really, you know, preferring this tick host and is able to thrive in this environment. I'm Ira Flater. This is Science Friday from WNYC Studios. Talking ticks with CMA Chow, assistant professor, biochemistry, and biophysics at UC San Francisco, for the ticks that have the bacteria that cause a, let's say, Lyme disease, why doesn't the tick itself get infected with Lyme disease. Yeah, so this is hitting on an important aspect of the biology,

which is that these microbes are pathogens to us as humans, but they're not pathogens necessarily to the ticks. In fact, the reason they can coexist so well is because they're living in harmony. So they're more of what we would refer to as a symbion or commensal, which has a more neutral or potentially beneficial relationship with the host. And, you know, conversely could be true. Some microbes that are commensal to your skin could end up being pathogenic to the ticks. So is it that the lime doesn't recognize the tick as something to attack? Or is there something about the tick that defends against? Or is it sort of a symbiotic thing going on?

That's a million-dollar question. I mean, we think it's probably a combination of the two. That's certainly what studies in other systems would suggest. So we're really just at the beginning of figuring all of this out. I think it's probably a combination. Yeah. And there is a bit of a West Coast, East Coast split that happens with the text, right? West Coast, best coast. I'll ignore that. No, I'm in California. I have to be very nice. Ticks in California prefer to bite lizards. Is that right? And Eastern ticks like rats? Correct. So on the West Coast, there's a tick called the Exotis Pacificus tick, which can intrinsically carry and transmit the pathogen for a lime.

But the reason we're kept safer on the West Coast from this is that these ticks prefer to feed on lizards, which do not carry Borrelia burgdor fry. So because their blood meal host partner doesn't have it, most of the time they don't have it. There are situations if the lizard's not available that they can feed on other animals like squirrels that may be carriers of it. And then that's where we run into some problems. So I was going to follow up on that. So if a East Coast tick makes it to the West Coast, and, you know, well, you'll travel on airplanes or whatever, right? Yeah. Does that mean it's not going to survive out here?

Like whether it could proliferate in the population? Yeah. Unless it came along a female and a male and they magically found an animal to feed and mate on together, it's pretty unlikely that it would proliferate. I know there are ticks that may cause a meat allergy. Right? How does that happen? Yeah. So that is a, I'm from Texas, so I get a lot of questions about this for my friends from Texas. So this, we don't know what's causing this in terms of whether there's a microbe responsible. This actually ends up being an allergy against this sugar modification that somehow is now associated with red meat.

And so there are a lot of different groups trying to look into this, whether there could be something we just don't know of a microbe maybe in there that's, causing this allergic reaction or if it could be something related to the tick, but it's restricted to a different type of tick from the genus amblyoma. So it's the lone star tick. Are you going to make a career out of studying? I mean, you go on to a different arachnoid? You know, who knows? I mean, that's the beauty of science research is that you never know where you're headed. Thank you very much for taking time. Thank you so much. CMA Chow is assistant professor of biochemistry and biophysics at the University of California in San Francisco, and you can see a photo of Dr. Child's Lab and all the ticks up there in our website

at ScienceFriiday.com slash ticks. And that's about all the time we have for this hour. If you missed any part of our program or you'd like to hear it again. Yeah, subscribe to our podcasts or ask your smart speaker to play Science Friday. And our second video from Breakthrough, Portraits of Women in Science premieres today, and it features paleontologist Jingmey O'Connor, who talks about how the field has changed. It's no longer just like manly men who go to the field and dig.

You know, now you have like, you know, girls like me. You can check out the video at breakthroughfilms.org. And on our Science Friday Voxpop app this week, we want to hear from our listeners, you folks out on the West Coast. Are there long-term health effects due to the wildfires that concern you? We want to hear from you. Are there long-term health effects due to the wildfires? wildfires you're concerned about. Tell us about it on the Science Friday Voxpop app wherever you get your

apps. You can also always say hello to us on social media, Facebook, Twitter, Instagram, or email us the old-fashioned way, SciFri at ScienceFriday.com. Tell us what you'd like us to cover. Have a great weekend. We'll see you next week. I'm Ira Flato.