Science Friday - Managing Invasive Plants And Ticks Together | Clue Into The Evolution Of The Bird Brain

Episode Date: November 19, 2024

Researchers are connecting two ecological problems in the Northeast in hopes of reducing the risk of tick-borne illnesses. Also, a “one-of-a-kind” fossil of Navaornis hestiae helps fill a giant gap in scientists’ understanding of how bird brains evolved.Managing Some Invasive Plants Might Reduce Blacklegged TicksIn much of the eastern US, October and November usher in an autumn peak of the blacklegged tick season.For years, researchers have noticed that these ticks, also called deer ticks, are more abundant on certain invasive plant species, like Japanese barberry, that create dense thickets in the forest understory. Now, a group of scientists in Vermont and Maine is investigating how managing these plants might decrease the number of blacklegged ticks—and the risk of people developing tick-borne illnesses, like Lyme disease and Babesiosis. After getting a $1.8 million grant from the National Science Foundation, they’re hoping to come up with guidance for landowners.Read the rest at sciencefriday.com.Ancient Bird Fossil Offers Clues Into How Bird Brains EvolvedArchaeopteryx is the earliest bird-like dinosaur that we know of. It lived 150 million years ago, but researchers don’t know much about how the bird brain evolved from then to now.An 80 million-year-old bird from the Mesozoic Era is now helping fill in the blanks. It’s called Navaornis hestiae. Researchers uncovered a fossil of this species, which was previously unknown to science, in Brazil in 2016. That specimen has a remarkably well-preserved skull, which a team of paleontologists used to digitally reconstruct the bird’s brain. The researchers recently reported their findings in the journal Nature.Ira talks with a lead author of the study, Dr. Luis Chiappe, a paleontologist and curator at the Natural History Museum of Los Angeles County in California.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Nova Ornus Hestii is a little bird that's about 80 million years old, and it's helping scientists piece together how bird brains evolved. They look very, very much like that of a modern bird. And yet, the bones that made up this skull are primitive. So in a sense, it's like if you were to be building the Empire State building with Adobe bricks. It's Tuesday, November 19th, and you're listening to Science Friday. I'm SciFRI producer Rasha Auredi. A little bit later, we're going to get into why we know so little about what happened to birds' brains between archaeopteryx, which was the earliest bird-like dinosaur, to the birds we know now.

But before we get to bird brains, we'll learn how black-legged ticks, also called deer ticks, might be hanging out with invasive plant species. Here's Cy-Fri's Kathleen Davis. Black-legged ticks, also known as deer ticks, are a big problem for both people. and wildlife in the eastern United States. Their bites can spread bacterial infections like Lyme disease, and their populations have spread over the past few decades. Researchers in Vermont and Maine have noticed an interesting correlation between ticks and invasive plant species. A better understanding of this could have an impact on how we manage both. Here to talk about this project is my guest, Lexi Krupp, Science and Health Reporter for Vermont public based in Burlington, Vermont. Lexi, welcome to Science Friday.

Thanks for having me. So tell us about this project that you reported on. What exactly are these researchers in Vermont and Maine trying to figure out? Just backing up for a minute, there have been a couple studies showing this link between an invasive shrub, Japanese Barbary, and black-legged ticks. And if you haven't seen Barbary, it's this bush that can grow over your head. It has small leaves that turn red in the fall and bright red berries. It's pretty. A lot of people will plant it in their yards. But in the forest, it can really take over the understory. A while back, researchers in Maine noticed that there were way more black-legged ticks on these plants.

Twice as many ticks in forests with Japanese Barbary compared to nearby forest. with native shrebs. Then a few years ago in Connecticut, other researchers found if you cut down Barbary, there's fewer ticks. So this new project that I covered is funded by the National Science Foundation. They have almost $2 million to test this idea out over a longer time period, five years. So these researchers are going to experiment with different methods of removing these plants. They're looking at whether you see a reduction in tick numbers nearby in surrounding areas. And they're looking at other invasive species too, plants like honeysuckle and common buckthorn that also take over the understory of forests. To see, can we find this connection between ticks and invasive plants as well?

Associate Professor Allie Gardner is the project lead. She's a medical entomologist at the University of Maine. And she said at the end of this studying, she really wants to be able to give landowners practical advice. The bottom line is that, you know, we can do all the ecological research we want on the problem. But if we're not actually able to translate our findings into recommendations, you know, ultimately we're not going to make any headway on the problem. So what's the science behind what these researchers are saying? I mean, why do ticks seem to like these invasive plants? One thing that might be going on is black like a white.

ticks like sort of damp environments. They'll actually dry out if they get too much sun. And Barbary, and maybe some of these other invasives too, offers this dense, shady habitat where ticks can hang out. Another piece of the story here is the other animals that are part of a ticks life cycle, which is mainly white-footed mice and white-tailed deer. Mice and deer also like to hang out in these areas with plants like barberry and honeysuckle, they offer some protection from predators. And while mice and deer are seeking shelter in these areas, they're also carrying a bunch of ticks. Hold on. Just let me get some clarity on something. Is it still tick season right now? I was always under the impression that tick season was in spring and summer. It is still tick season.

And this is really confusing because the mosquitoes are gone. It feels like ticks should be gone too. But that's just not how their biology works. October and November is actually the peak of black-legged tick season in most of the eastern U.S. where I live in Vermont. This is when there are the most emergency room visits because of tick bites outside of the spring. And I think this is surprising every year because you find very few ticks in August and September. And that's because ticks are around, but they're teeny tiny, basically baby ticks, and they don't bite people and dogs. So it's not until they get to this adult phase later in the fall that they start looking for what's called a blood meal. So this project that we're talking about, it seems like it could be

the perfect solution for two problems, right? Like you're getting rid of invasive plants to get rid of ticks. But is this too good to be true? I mean, are there skeptics to this idea? Yeah. I think one issue here is that there are just so many variables when it comes to habitats that ticks like. I spoke to Professor Thomas Mathur about this. He's a tick ecologist at the University of Rhode Island and runs this program called tick encounter. And he said, you can certainly find ticks in places with invasive species. But there's also lots of ticks in areas without any invasive plants. And he's cautious about this connection between black-legged ticks and an invasive species like barberry. If you were to look at sort of people's interpretation of those studies, you would think,

oh, as soon as you go over to a barberry instead of those little red berries, they're going to be raining ticks on you. It's not that way. And he made this point that if you really want to reduce your risk of tick-borne illnesses, there's probably easy. ways to do it than removing a bunch of invasive plants. Tick checks are really effective, and so is spraying insecticides that are targeted at ticks. So what's next for this project? The research I talked about is starting next year, and they're still figuring out all the details, but the goal is to come out of this with best practices for how to manage invasive plants

with the best shot at reducing tick numbers. And I think another goal is to spread awareness of this connection between invasive plants and black-legged ticks. That might give people another reason to manage some of these invasive species on their properties. Well, that's all the time that we have for now. I'd like to thank my guest, Lexi Krupp, Science and Health Reporter for Vermont Public based in Burlington, Vermont. Thanks so much for being here.

It was a pleasure. After the break, Ira Flato talks with a paleontologist about how an ancient bird fossil is helping unravel how bird brains evolved. Stick around. Archaeopteryx is the earliest bird-like dinosaur that we know of. It lived 150 million years ago, but from then to now, well, researchers don't know much about how the bird brain evolved. There's a gap. But now, an 80 million-year-old bird fossil from the Mesozoic era is helping fill in this gap. It has a remarkably preserved skull, which scientists use to, originally reconstruct the bird's brain.

Joining me is a lead author on this study, Dr. Luis Kiape, paleontologist, at the Natural History Museum of Los Angeles County in California. Welcome to Science Friday. Thank you. Pleased to be here. Nice to have you. Tell us about this ancient bird.

What's its name? Where did it live? The name is Navajornis Hestia. And as you pointed out, it lived 80 million years ago in what is now southern Brazil, not far from the city of Sao Paulo. It looked very much like a plover, if you want, but it was not at all a plover.

It belongs to a group of archaic birds called an antionitis that were widespread during the Cretaceous period. They lived all around the world. But Navajornis, like other anantornitas, was a very capable flyer, and it had roughly the size of a plover. And what is surprising of this animal is how much the skull looks like a moanor skull, like the skull of a plover. Wow. So, but is it a direct descendant then?

It is not. I mean, all in Antioannitis died out with the mass extinction at the end of the Cretaceous, the same mass extinction that killed dinosaurs like T-Rex and Triceratops, 66. million years ago. So then why is this bird important for you to study? Two pieces of the story, if you want, are very important. On the one hand, as you pointed out in your introduction, the brain of this animal that we were able to reconstruct falls between archaeopteryx and that of a modern bird. So it really feels a very long gap that existed before. And on the other hand, what I think is really surprising and it was unexpected is that the geometry of this skull of this animal, by that I mean it has a slender bill, it has big eye sockets, it has a vaulted basic

ranium. That's where the part of the skull that contains the brain. They look very, very much like that of a modern bird. And yet the bones that made up this skull are primitive. They have primitive features. They're very dinosaurian looking. So in a sense, it's like if you were to be building the Empire State building with Adobe bricks. Yeah, I mean, it's surprising, right, and unexpected. This is a great example of what we call convergent evolution.

So in this case, Navarne's and, almost. modern birds had a common ancestor that is at least 130 million years old. So those lineages have been separated for 130 million years, and yet they converged in having the same geometry of the skull. That's interesting. As you say, that bird did not survive, but the other birds did. The modern birds did, of course. The modern birds did.

And so this fossil's lineage, which is extinct, developed civil. similar skull features to modern birds separately. Exactly. Wow, that is surprising. Yeah, and unexpected. And not just similar. Yeah. I mean, the similarity is remarkable, you know.

I mean, when you look at a, say, the skull of an animal, like, I'm using a plover because roughly that size, right, or a pigeon. And you put that skull on one next to the other, unless you're looking into the details of the bones, those skulls look remarkably similar. Okay, so now that we've met this bird, how did you go about reconstructing its brain? The way we reconstructed the brain is you use what is called a micro-CTM, a micro-computed tomographer. It's very much like an MRI, right? But much more precise and it's an x-ray-based machine.

So you have a bunch of x-ray slices that are very thin of the fossil. And then with software, you stitch them all together and you create a three-dimensional rendering, a three-dimensional image of this skull. And therefore, you could look into the internal portions of the skull without breaking it. And you could reconstruct what is the void of the body. brain preserved in the fossil. The brain is not preserved anymore, but you could at least reconstruct the void. That's where, you know, you do comparative anatomy, right? And you look at the brain of modern birds and the brain of other animals to be able to identify where the optic loaves are,

where the cerebellum is, and so on. Interesting. So what elements of this fossil then were similar to the earliest birds of those alive today? Well, what you have, for example, as most remarkable in terms of the brain, is that the brain is rotated. That means that, like in most modern birds, the connection between the brain and the spinal cord comes from the bottom of the skull, not from the back of the skull, the way it does, say, in a typical dinosaur or in archaeopteryx. So that is an advanced feature that you see, a modern feature that you see in the brain. Nonetheless, when you look at, say, the size of the cerebellum, the size of the other components of the brain, they look more primitive. We were able to reconstruct the inner ear of the bird.

And this is important because it's a very critical sensory organ, in particularly for an aerial animal that has to navigate. in three dimensions. In the inner ear of Navajornis is also very modern in appearance. Wow. So there are modern elements in this bird. Yeah. There's definitely modern elements. And there are also archaic elements.

And that's why this is somewhat in between. You mentioned about how surprising how this bird looked so modern. Did this fossil challenge what you thought you knew about bird brain evolution? I think it challenged what. what we knew about the convergent evolution that we see in the shape of the skull. I think that, you know, it also surprises, to me, it was surprising to have an inner ear that was so modern-looking. I didn't expect that. But what was more unexpected was really the fact that you have this modern-looking skull made up of this very primitive,

And that was completely unexpected. And, you know, it may be telling you that at the time of constructing a modern avian skull, the skull of a modern bird, you don't have too many ways of putting together a modern avian skull in that evolution used the tools that it had at the time in built a modern one based on basic bricks. I mean, does it ever get old studying, you know, creatures that live millions of millions of millions of years ago? No, no. I have done, you know, I've worked on early bird evolution for nearly 40 years, and this one was a mind-blowing discovery, but I'm sure that many others are going to come

in the future. I hope to see them. Where does this rank? Does this make it into the top five fossils of your career? Definitely. I think so. I doubted me. What number would you put it? Well, you know, I have found some very cool fossils during my lifetime. And I haven't found this one, you know, was found by an amateur paleontologist in Brazil. But I think that this is really one of those remarkable fossils. It's the best preserve avian skull in the Mesozoic worldwide. It's just beautifully preserved.

Could we actually see it ourselves at a museum someplace? It's in Brazil. It's at a museum, a small museum in Brazil, in a city called Marilia. You can see pictures. Yeah, we have pictures. Dr. Kiape, I want to thank you for sharing your knowledge and your discoveries. Thank you so much. Thank you for having me.

You're welcome. Dr. Luis Kiape is a paleontologist at the Natural History Museum of Los Angeles County in California. And that wraps up today's show. Lots of folks help make it happen, including Jordan Smudjik. Charles Bergquist. Shoshana Bugsbaum. George Harper. On tomorrow's episode, how bacteriophages,

aka viruses that munch on bacteria, are lurking all over your bathroom. But they might be doing you a favor. Catch you then. I'm SciFri producer, Rasha Oridi.