- Hi there, I'm Frank Graff.

Wildlife biologists believe traffic signs can help save the red wolf.

How a unique bridge in the North Carolina Mountains may help people and animals.

And how a mammal-tracking experiment accidentally found a way to stop an invasive species.

We're talking the science of animals all around us next on "Sci NC."

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[mysterious music] - [Announcer] Funding for "Sci NC" is provided by the North Carolina Department of Natural and Cultural Resources.

[mysterious music] ♪ - Hi again, and welcome to "Sci NC."

You know, science is filled with stories of new discoveries made when researching a completely different question, everything from material science to new medicines.

Well, producer Evan Howell introduces us to a North Carolina scientist who was studying the disappearance of small mammals in Key Largo, Florida.

He had one theory, but what he found was completely unexpected.

[mysterious music] - [Evan] What do opossums, Key Largo woodrats, and dumpster-diving cats have in common?

Burmese pythons, of course.

That's right, pythons.

- Unfortunately, my work went from studying mammals to mostly studying pythons.

- [Evan] Because these pythons are eating all three of these mammals.

That's devastating the South Florida ecosystem, and that's a serious problem.

- [Mike] And how to detect them, find them, manage them to prevent the extinction of these endangered rodents and largely mammals across the Florida Keys.

- [Evan] Mike Cove is a curator of mammals at the North Carolina Museum of Natural Sciences.

He studies the delicate balance of ecosystems and the impact of invasive species.

- I don't love pythons.

I have a respect for pythons and think they're fascinating animals.

Unfortunately, they don't belong in the United States.

- [Evan] But before we go any further, let's go back to the start of Cove's research.

It's an 11-mile stretch at the Crocodile Lake National Wildlife Refuge in Key Largo, Florida.

Cove was studying two endangered rodents for his dissertation in 2012.

They're the cotton mouse and the Key Largo woodrat.

- So Mike, you track pythons, but from the looks of it here, it didn't really start out that way.

- Right.

- Can you tell us a little bit about that?

- Yeah, yeah, yeah.

So I've been working in the Florida Keys for 10 years now, and I started in the Florida Keys with this species here.

This is the Key Largo woodrat.

This is an endemic rodent.

It only lives on the island of Key Largo.

The typical ecosystem engineer is the beaver, right?

They build large dams.

Well, these small woodrats also build large stick nests.

This small rodent is carrying sticks sometimes two, three feet long as far as 50 yards to pile them onto these giant stick nests and provide all types of ecosystem services because they're basically creating giant compost heaps that help restore the soil and create habitat for lots of other animals that also live inside the nest with them.

[mysterious music] - [Evan] But their population was declining, and Cove needed to figure out why.

He started to look at feral cats that came into the area from neighborhoods nearby.

[cat meows] Note that these cats are technically an invasive species spread by humans.

The cats were already dumpster diving and getting fed by sympathetic people, and Cove saw that the opossums and raccoons were taking advantage of that extra food source as well, then going back into the forest.

More food meant they would multiply and disrupt the wood rat habitat, but he saw other dangers as well.

- [Mike] Yeah, so we started tracking possums and raccoons to evaluate how much time they were spending in the wildlife reserves versus outside gaining external resources from eating cat food.

But in doing that, we were also looking at potential disease spread from cats to raccoons to ultimately affect the rodents.

- [Evan] Look to the right of your screen and you'll see.

All that led him to something that definitely didn't belong and was yet another threat to the ecosystem.

Burmese pythons, which is considered an invasive species as well.

- [Mike] Secretly, we knew that the Python population was growing, and you know, I've always kind of thought, man, wouldn't it be wild if one of these got eaten by a python?

And it led us to this homing beacon with this animal inside the python's stomach.

- [Evan] It took a full month to realize their first tracked opossum had been eaten by a python.

Then they had to go get it.

[mysterious music] - [Mike] The Florida Keys are a big fossilized coral reef, right?

So there's tons of places for them to hide.

- [Cameraperson] [laughs] He totally just peed, didn't he?

- So on average, it takes three to four full-grown humans to several hours to pull a python out of the ground.

These things are pure muscle.

- [Evan] But just like that, Cove had discovered a way to track them.

So what's an invasive species?

Enter the pythons, snakes that were never part of the natural plan and have taken over South Florida, particularly in the Everglades National Park, into the South, and Key Largo.

- [Cameraperson] Wow.

- [Evan] The pythons are devastating the ecosystem.

- [Mike] In the Everglades, it's almost a mammal desert, there's basically no mammals left.

- [Evan] Where did these pythons come from?

According to the Nature Conservancy, the first Burmese python was found in 1979, and it was likely a former pet which was released or escaped.

And since then, they've multiplied, and they might be moving northward.

- [Mike] The climate models and the habitat suitability models suggest that they could make it all the way up into North Carolina without any type of, you know, increasing warming of the climate or anything like that.

They could exist and persist in North Carolina right now if they were able to establish.

- [Evan] The State of Florida has efforts underway to reduce the Python population that even include contests for cash money.

Meanwhile, Cove says it's ironic they're trying to get rid of the pythons but says there's little choice.

- You know, the sad reality is these Burmese pythons are rare and endangered in a lot of their endemic native range in Southeast Asia, but their sad reality is just because they're common here doesn't mean that we can celebrate that, that this is, you know, a backup population for this endangered species.

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It's not pythons, it's vehicles that are putting wild animals like bears and elk in danger in the North Carolina Mountains.

Producer Rossie Izlar explains how scientists believe a wildlife crossing could keep animals and people safe and bring habitats back together.

[mysterious music] - [Rossie] This 28-mile stretch of I-40 in Western North Carolina is not your average highway.

For one, it bisects two massive wildlife preserves: the Great Smoky National Park and the Pisgah National Forest.

It's also an incredibly deadly corridor for wildlife, especially for black bear, white-tailed deer, and elk.

And lastly, this stretch of highway is busy.

Over the last 16 years, traffic on the road here has increased by 42%.

- It's such a small space for everybody to be on.

You know, you've got the mountain on one side and you got the river on the other side practically the whole way.

- Wildlife is getting hit and killed on the roadway, that's a problem, right?

And then there's the public safety.

You don't wanna run into an animal, much less a bull elk, which can run 1,000 pounds.

- [Rossie] I-40 cuts through the hunting and mating grounds of these charismatic species, but there's also a longer term problem: warming temperatures due to climate change.

[calm music] - And in order to track climate, they're gonna need to go up the Appalachian chain, that means crossing Interstate 40.

So the fact of the matter is when we get to 35,000 vehicles or 40,000 vehicles or 45,000 vehicles a day, at some point in time, that corridor's gonna be an absolutely hard barrier, and practically nothing will be able to cross.

And that's a bigger problem than actually seeing dead bears on the side of the road, because wildlife needs to move.

- We wanna create safe passage from the biodiverse animals and wildlife in Great Smoky Mountain National Park to these areas in the Northeast or other protected lands.

We wanna be able to mitigate and allow our wildlife to move so that they can, you know, survive some of these fluctuations that we're seeing in the environment.

- [Rossie] Thankfully, the needs of wildlife in this region align with the needs of the departments of transportation in North Carolina and Tennessee.

Five bridges along this stretch of highway need to be replaced, starting with the Harmon Den bridge.

As DOT replaces these bridges, they'll be adding in features to make it easier for wildlife to cross the busy highway.

Here at Harmon Den, that means building two paths along the creek with nine-foot guardrails that guide animals there instead of over the highway.

- I mean, it's a whole culture shift of looking at all the users of the road and not just the cars or the trucks, but you have to look at all the users.

[gentle music] - [Rossie] Nationally, roads kill about 12% of North America's wild mammals.

- A lot of the wildlife vehicle collision information we get, it's a small fraction, right?

And just kind of what you see anecdotally or what somebody reported.

- [Rossie] The 2021 Infrastructure Bill includes $350 million for wildlife crossings like this one.

The gold standard is of course a dedicated wildlife overpass like this one at Banff National Park in Canada or this crab crossing on Christmas Tree Island in Australia.

But these bridges are expensive.

- We essentially, through this 28-mile section of road, want multiple, a linkage system, multiple opportunities for wildlife to cross through there.

So retrofitting what we already have, not to mention the structures that are already working, but trying to get a dedicated wildlife overpass or two, those are the expensive things that can be the big elephant in the room.

But truly, I think to improve connectivity in the Gorge and what we're talking about here, you know, on this large landscape, making sure important diverse wildlife can move.

We need dedicated overpass or underpass structures for wildlife specifically - We need to actually accommodate these animals and their need to move, and in the process, we make it safer for the motoring public.

- [Rossie] Follow us on Instagram for beautiful images of North Carolina and cool science facts.

- We're still talking about roads, and it turns out cars traveling on the busy roads of the coastal plains are threatening red wolves.

Think the roads on the way to the outer banks.

Remember, North Carolina is home to the only confirmed wild population of red wolves in the country.

The U.S.

Fish and Wildlife Service is trying to restore the population in the Alligator River National Wildlife Refuge, which those roads go straight through.

Producer Cassia Rivera explains how the service hopes traffic signs may help save the red wolf.

[calm music] - [Cassia] As the sun rises over Eastern North Carolina, the sounds of nature usher in the beautiful echoes of habitats teeming with wildlife.

[birds chirping] [birds chirping] [crickets chirping] [owl chirps] [water lapping] [birds chirping] Over 200,000 acres of pristine protected lands create a safe haven for flora and fauna.

These unique habitats consisting of wetlands, farmlands, and hardwood forests are home to a diverse range of reptiles, amphibians, fish, birds, and mammals.

The rich and diverse ecosystem here plays a key role in supporting a thriving wildlife population.

Unfortunately, not every species has a bright future.

With less than 20 individuals left in the wild, the critically endangered red wolf struggles to safely navigate towards survival.

What is one of the biggest challenges these red wolves face?

[somber music] Habitat fragmentation.

Highway systems used by locals and tourists and for the transportation of goods flank and intersect these protected wildlife habitats.

During the past decade, five counties within the U.S. 64, 264 highway corridors documented over 8,000 vehicle and wildlife collisions.

Over 1,000 humans were injured, and 18 human lives were lost.

[somber music] [somber music continues] [somber music continues] [somber music continues] [somber music continues] [somber music continues] [warmhearted music] Protecting the path of the red wolf has remained a great challenge to North Carolina conservationists.

Fortunately, there are those behind the scenes who continue to work tirelessly to give red wolves their right of passage.

[warmhearted music] - Last spring, early summer, we released four captive born red wolves, and three of those four died as a result of vehicle-strike mortalities.

And if you look at the history of the red wolf program over the course of time since 1987 when they were first reintroduced, vehicle-strike mortalities were the second leading cause of mortality.

But when you're releasing captive-born adults, they probably are gonna have an even higher percentage of vehicle mortality, so that just drove home to me and all of us that we need to do something more to try to reduce vehicle mortalities.

- [Cassia] Highway caution signs are strategically placed where red wolf movement has been tracked by collars equipped with GPS technology.

- We came on this idea of these mobile highway signs.

The intention was to put them proactively around on the highways closest to where we were releasing new red wolves.

We determined the closest points, and we put one on each side to alert motorists that it was potential that you would have a red wolf crossing.

And the signs have had a lot more impact than even we imagined.

We imagined that they would alert visitors in that area that there was red wolf crossings and potentially reduce vehicle-strike mortalities, but people are noticing those signs, and it's getting a lot of buzz, a lot of social media, a lot of talked about.

And the communities are recognizing, even ones that didn't even necessarily know they lived near a red wolf population, that there are red wolves here.

- [Cassia] Orange collars with reflective strips are placed on newly released wolves in hopes that they will be easily identifiable to the public and visible to motorists at night.

- So when they see that orange reflective material, they'll know that's a red wolf on the highway and be able to adjust their driving as they can.

And we've seen with these new releases, there have been several of them that have been on or near highways, and we've gotten lots of reports that people are seeing that orange reflective material, and I've seen it myself, and I do believe that it has reduced vehicle-strike mortalities with these new releases.

- [Cassia] The implementation of these orange collars along with the strategic placement of the mobile highway caution signs are just some of the pieces to the puzzle in creating a safer environment for red wolves to travel within.

Prey for the Pack is an initiative started in hopes of creating habitat connectivity.

[warmhearted music] [warmhearted music continues] - I really love Prey for the Pack.

I think it's such a great initiative and partnership because not only does it tackle the public perception problem that we have where, you know, there's a lot of misconception going on, but it also tackles the habitat connectivity problem that we have going on.

And in addition to that, it also help local landowners that want to accomplish big projects that may not have the methods or the ability in order to do it.

And it's a really great win-win-type situation because we get to help inform and bring awareness to the public as well as help them achieve projects that they've been really wanting to do.

I'm hoping we get more people, but it's a really great program.

- [Cassia] While connecting habitats is critical to the survival of red wolves, education to dispel the misconceptions surrounding them is also a key component to the success of their future.

- When I do a program, the first thing I say is, "I'm gonna say the word wolf, and you tell me what you think."

Usually it's snarling and teeth, so okay, so people see wolves as snarling, they're gonna attack me.

So then I need to talk about how wolves communicate and how they use their body, they use their teeth, their tail, their body posture.

How does that communicate?

What does that mean?

Well, we know through studies what that means, and so that's important.

I think wolves are incredible families.

There is some sense of family, and that's really important to them, and we know that not just because we're humans and we see that, there've been a lot of studies that show that wolves are a really good family unit.

I think it's something we can relate to, and I think finding those points as humans that we can relate to an animal, I think, helps us understand it better.

[warmhearted music] [warmhearted music continues] - [Cassia] Join the pack to help give red wolves their right of passage.

[warmhearted music] [warmhearted music continues] - [Rossie] Check out our weekly science blog to take a deeper dive on current science topics.

- As we've seen, the animals all around us need to adapt to changing environments, they really have no choice, and that's especially true in a state with a growing population like North Carolina, and those changes can be natural or manmade.

People need to adapt to the needs of animals as well.

And as "NC Culture Kids" shows us, plants need to adapt to change as well.

- Hello, I'm Brandon, and I'm here today at the Carolina Beach State Park, and today we're gonna check out some plants with some very unusual adaptations, so let's check it out.

Hey, Jesse.

- [Jesse] Hey, Brandon.

- Hey, guys, this is Jesse.

He's gonna show us around, we're gonna take a look at some carnivorous plants today.

Ready to go?

- Sounds good.

[air whooshes] - Okay, so Jesse, what makes this place unique?

Why here?

- So at Carolina Beach State Park, we have a number of carnivorous plants, and those carnivorous plants thrive in an environment where soils are poor of nutrients.

They still go through photosynthesis, but they need to digest and catch insects to get their nutrients.

- So you can understand how a carnivorous plant sounds like alien to me.

How does a plant evolve to or adapt even to eat bugs?

- Yeah, so the adaptation works to trap insects, and they use their digestive enzymes to then break down the insect and absorb the nutrients.

For instance, the Venus flytrap that we have here, so Venus flytraps have an unusual interdependence with insects.

Their flowers in spring feed nectar to visiting bees and beetles, and without these insect pollinators, the flytraps wouldn't make seeds.

So pollination is a case where everyone wins.

The flowers are on a tall stalk about three to four inches above the deadly jaws so that these plants rarely kill their insect friends.

Lower to the ground is where the strangest adaptations come into play.

The flytrap leaves attract different insects.

The bright colors and sweet-smelling nectar lure in ants and spiders and other invertebrates.

Tiny hairs on the leaves sense movement, and if something touches the trigger hairs more than once within about 20 seconds, the jaw leaves snap shut.

The amazingly adapted flytrap leaves then turn from an open trap into a closed stomach, which releases enzymes that digest the bug in about a week, absorbing its nutrients.

Venus flytraps grow with sunlight and eat insects, which makes them unique in being both producers and consumers in their ecosystem.

- It was really cool getting to see the Venus flytraps in the wild out here.

- Yeah, from right where we're standing here, Venus flytraps are only found within about a 70-mile radius, nowhere else in the world.

- Cool, what if I wanna take one home today?

So the Venus Flytraps that are found here are wild, so we wanna protect them.

Unfortunately, some people come and will try to steal them or poach them, but that's why park rangers are here to protect the the plants that are here in wild.

So anywhere where Venus flytraps grow in the wild, they're protected.

- And that's it for "Sci NC" for this week.

If you want more "Sci NC", be sure to follow us online.

We are on all the social media channels for stories like this as well as written blogs and a lot of other content.

For now, I'm Frank Graff.

Thanks for watching.

[mysterious music] ♪ [mysterious music continues] ♪ [mysterious music continues] ♪ [mysterious music] ♪ [mysterious music continues] ♪ [mysterious music continues] ♪ [mysterious music continues] ♪ [mysterious music continues] - [Announcer] Funding for "Sci NC" is provided by the North Carolina Department of Natural and Cultural Resources.

- [Announcer] Quality public television is made possible through the financial contributions of viewers like you, who invite you to join them in supporting PBS NC.