The Great Smoky Mountains' Incredible Firefly Light Show

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Today, the rare Smoky Mountain fireflies are a tourist attraction. Twenty years ago, science didn’t believe they existed.  

At exactly 9:27 P.M., when dusk slips into darkness in the Great Smoky Mountains National Park, the “light show” begins. It’s June, and for two weeks in Elkmont, Tennessee, the fireflies pool their efforts. Instead of scattershot blips of light in the summer sky, the fireflies—thousands of them—pulse this way for hours, together in eerie, quiet harmony. It’s as if the trees were strung up with Christmas lights: bright for three seconds, dark for six, and then bright again, over and over. It continues this way for hours.

As a child, Lynn Faust would huddle with her family on the cabin porch to watch the spectacle. They’d sit, mesmerized by the “drumbeat with no sound.” And though they’d appreciated the show for generations, Faust never thought the event was newsworthy. “I’d assumed there was only one kind of firefly and thought they did a nice show in the Smokies,” she says.

The natural world has long enchanted Faust. In college, she majored in forensic anthropology and minored in forestry. In her twenties, she circumnavigated the globe for three years, visiting islands you could only get to by boat, learning about cultures before they disappeared, pursuing underwater photography. Today, at 60, she’s a naturalist who writes scientific papers and field guides about fireflies. But she wasn’t always obsessed with the insect. In fact, her academic interest began only in the ’90s, when she read an article by Steven Strogatz, a Cornell mathematician, in which he marveled at a species of Southeast Asian firefly that synchronized its flashes. Highlighting how rare this phenomenon was, Strogatz noted that there were no synchronous fireflies in the Western Hemisphere.

This struck Faust as odd. It contradicted the light shows she had seen growing up. As she dug deeper, Faust found that while there had been more than 100 years of colloquial accounts of North American fireflies flashing in sync, scientists discounted those reports, attributing them to lore or optical illusion. Faust knew the truth: that her Tennessse fireflies were every bit as special as the species in Asia. But how could she prove it?

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Fireflies—or lightning bugs—may be the closest thing nature has to a magic trick: lighting the world from the inside out. Technically, they are bioluminescent beetles. Their glow comes from an internal chemical reaction that combines oxygen and calcium with a series of enzymes, including a key light-producing one called luciferin. The bugs flash for lots of reasons: to communicate, to attract mates, to scare off predators. But for creatures so striking, they’re also common. There are roughly 2,000 species worldwide and 125 or more in North America alone, where catching them is a childhood rite of passage.

More than 20 years ago, Faust wrote a letter to Strogatz after reading his article. He connected her with Jonathan Copeland, a biologist and professor at Georgia Southern University who was studying firefly behavior in Malaysia and Indonesia. Copeland was skeptical of Faust’s tale. Reports of synchrony had crossed his desk before but had never panned out. “The dogma said they do not synchronize in North America,” he says.

Still, he indulged Faust, asking her to describe what she’d witnessed by drawing a “musical score.” As a child, Copeland, a tuba player, dreamed of playing with the Boston Symphony. Ever since, music dominated his approach to the natural world. In grad school, he’d studied and documented the rhythmic lunge and strike patterns of praying mantises. He took a similar slant on firefly behavior and found that if people charted the synchronic rhythms they were witnessing, he could separate a bogus account from a real one. Putting pencil to paper, Faust was nervous. “To look at it scientifically is very different from sitting in your rocking chair with a blanket and enjoying it,” she says. “I didn’t want to sound like a complete idiot.”

When her note arrived, “it looked like synchrony on paper,” says Copeland. In June 1993, he was intrigued enough to make the eight-hour drive to Elkmont. He pulled into the cabin’s driveway as dusk fell, no trace of the insects to be seen, and promptly fell asleep—only to wake up to flashes of light all around him. “It was completely obvious—no doubt about it!” he remembers. He rushed to find a pay phone to call his colleague Andy Moiseff. “It must have been about midnight,” he says. “I said, ‘Andy, Andy, you’ve got to see this, they’re flashing synchronously!’ Andy laughed and said, ‘Prove it,’ like any good scientist.” The following summer, that’s exactly what Copeland, Faust, and Moiseff, a professor of physiology at the University of Connecticut, set out to do. It was an unlikely partnership, but the trio made a formidable team. Copeland is a neuroethologist—he studies the neural basis for animal behavior. Faust, an unflappable outdoorswoman and keen observer, knows the area and its wildlife like home. And Moiseff is a computer whiz, with a proclivity for dreaming up theories and building devices to test them.

The three hauled lab equipment, microscopes, video cameras, computers, and insect specimens to sites throughout the Smokies. They started in Elkmont but quickly branched out to determine how widespread the phenomenon was. They hauled bugs back to the lab to do frame-by-frame analyses of the flashes. In the wild, “they were obviously in sync,” Copeland says. But when they repeated the test with individual fireflies in one-gallon freezer bags, the behavior changed. If an insect couldn’t see another, they no longer flashed synchronously. By 1995, the team had the data they needed.

“This was red-hot news in the firefly community,” says Copeland. There are four synchronous species of firefly known in Asia, and they are smaller than the team’s species, Photinus carolinus. “Their flash is wimpy in intensity, but what they lack in flash intensity, they make up in numbers,” Copeland says. They usually remain stationary in trees along the river, unlike carolinus, which fly around in the woods. “Ours are more complicated,” says Faust.

Proving synchrony existed in fireflies in the Western Hemisphere was exciting, but it raised questions about why they flashed this way. And how was that different from what their cohorts did in Asia or, for that matter, from the way their asynchronous relatives behaved in North America and even elsewhere in the park? For the next two decades, Copeland and Moiseff would study the fireflies with Faust each summer, determined to understand these magical creatures. But just as they were getting close, everything in Elkmont changed.

In the beginning, the team had the woods to themselves. “In the old days, there would be the three of us and the odd stranger who was fishing,” says Moiseff. In fact, when Faust first informed park officials about the light show, they didn’t believe her. In 1992, her family had to give up its cabin when the government took control of the resort community’s leases. By then, Faust had noticed that the firefly behavior seemed to be localized: The light show didn’t appear to be taking place even half a mile away from this settled location. She hypothesized that the synchronous behavior could be linked to the unusual conditions near the homes. But when she pointed it out, parks officials assumed her claims were a trumped-up attempt to keep her cabin.

Finally, in 1996, park administrators sent a ranger to the researchers’ campsite to investigate. “It was a funny night,” Faust recalls. “We had this ancient computer set up on the porch and Christmas lights strung across the hill to see if we could control the rhythm of the firefly flashes with the lights going off and on. He was like, ‘Where are they?’ And suddenly, there they were. The guy goes, ‘Oh, my God.’ He said that about six times,” says Faust. The next night they had 20 rangers watching.

By the early 2000s, word had spread. According to one of the park’s supervisory rangers, Kent Cave, “There were fender benders, road rage, crowds of people.” The Smoky Mountain fireflies had become a bona fide tourist attraction. In 2006, the park instituted a trolley service from a parking lot to the viewing area for peak nights, closing access to individual cars. “People were driving up. They might have driven five hours from Alabama or down from Lexington and couldn’t get in,” says Cave.

Today, tourists reserve parking spots in advance online. After the year’s peak firefly emergence has been predicted, reservations for the June viewings go live in late April. The spaces go in minutes. The light show has become the biggest of the park’s special events, with as many as 12,000 attendees in recent years. But as Cave puts it, “Our biggest headache is predicting when these little buggers are gonna flash.” There’s a system for that too. “The pressure of me telling people when to come see the fireflies began 20 years ago,” Faust says. “Like anything in nature, it’s not entirely predictable, but I’ve developed a mathematical way of figuring it out.”

Today, park entomologist Becky Nichols relies on Faust’s degree-day model to determine when the fireflies will emerge. The equation is specific to Photinus carolinus and relies on temperature data Faust and Nichols begin collecting in early March. “You take the high and the low temperatures and plug them into a formula to figure out the larvae’s accumulation of growth,” explains Nichols. “The issue in the past was that we didn’t have good temperature data.” Tiny temperature loggers fixed to trees for air temperature and to the ground for soil temperature have remedied that problem. Faust has her own data logger down the road as well, and the two women compare results as the numbers climb, hoping to come up with the same prediction independently.

Though they’re gratified that the public appreciates the light show, its popularity is bittersweet. The event is too crowded for the scientists to continue studying at the site, so they’ve decamped to other areas in the Appalachian Mountains. As Copeland says ruefully, “We can’t work there anymore because it’s a tourist attraction, and we’re largely responsible for that.”

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So why do Photinus carolinus flash together? No one has quite figured it out, Faust says. But there are theories. In a 2010 paper published in Science, Moiseff and Copeland suggest that synchrony keeps the female firefly from getting confused when searching for a mate. In an experiment using an electronic simulator with light-emitting diodes, they found that uncoordinated stimuli—too many lights coming from too many places at different times—inhibited the female firefly’s response. When flashes were coordinated, the females could clearly send their messages back to the males. Faust agree that synchrony in carolinus is related to mating.

Moiseff, who’s most interested in the firefly’s brain and nerve cells, wonders what it is about the insect’s eyes that helps it process information. Some data has shown that under the right circumstances, a firefly can determine where a flash is coming from. What this could suggest, he says, is that the insect’s brain might break information into different pathways for processing—something that primates and people do, but we don’t think of bugs doing. It’s a problem he’s still studying: “How does a simple nervous system accommodate that? What’s the mechanism?”

Moiseff also points out that Photinus’s synchrony is important not because the phenomenon is so rare but because it changes our perspective on the many ways in which living things interact. With just one proven case in the U.S., the gates opened wide for discovering others. In 1998, Copeland and Moiseff showed that a species on the Georgia and South Carolina coast, Photuris frontalis, was also synchronous. Additionally, the species Photinus pyralis, Copeland says, is “weakly synchronic.” Once you find other species doing this, “all of a sudden they’re not a freak of nature. Instead, they have a solution to a specific environmental need,” says Moiseff.

The last few years, Moiseff and Copeland have kept their firefly studies closer to home. “For the first 10 years, my spouse was very supportive,” says Copeland of his work in Tennessee. “Then she started asking questions about the significance.” He retires from his position at Georgia Southern this year, and, joking aside, considers identifying Photinus’s synchrony to be one of the highlights of his life. “I grew up as a suburban kid afraid of the dark, and I found myself [alone] in the woods with fireflies,” he says. “Serendipity—and a mind set that gets you away from cable TV—plays a role in science.”

Faust, for her part, is still involved with fireflies. She’s working on a field guide that will include images from her collection of more than 60,000 photos. And her family cabin still stands proudly in the same spot where she first saw the light show. But it isn’t quite the same. The cabin now belongs to the park, and she and her family no longer curl up on that porch under thick blankets, waiting for the pulsing spectacle to begin. One thing hasn’t changed, though: No matter how many times Faust has seen the show, Photinus carolinus’s return each summer is still a thrill. “The biggest kick is trying to predict the first night,” she says. “To see that first one and think, ‘Wow, that happened again.’”

This story originally appeared in an issue of mental_floss magazine. Subscribe here.

The Tower of London Welcomes New Baby Ravens for the First Time in 30 Years

Some of the baby ravens born at the Tower of London
Some of the baby ravens born at the Tower of London
Tower of London Twitter (screenshot)

There are some new residents at the Tower of London. They're only about 11 inches tall, are very noisy, and eat rats for breakfast, lunch, and dinner. Fortunately, they're also adorable—not to mention protected by legend.

On May 17, the Tower of London announced that their breeding pair of ravens, Huginn and Muninn, had welcomed four healthy chicks, the first born at the Tower since 1989. The ravens are part of an unkindness that's been located at the Tower for centuries as a sort of protective asset. According to legend, the Tower must always have ravens, or both the Tower and the kingdom will fall. It's not exactly clear when the legend began, but according to the Tower, Charles II decreed there must always be six ravens present.

Huginn and Muninn are newer additions, having arrived at the Tower in late 2018, and they weren't expected to breed this spring. So it was a surprise in mid-April when the devoted Tower Ravenmaster, Yeoman Warder Chris Skaife, noticed something exciting going on. "My suspicions were first piqued that we might have a chance of baby chicks when the parents built a huge nest suddenly overnight and then almost immediately the female bird started to sit on it," Skaife said in a Tower press release. On April 23, Skaife noticed the birds flying to the nest with food, but it was only this week he was able to get close enough to see the four healthy chicks. The sight delighted him: "Having worked with the ravens here at the Tower for the last 13 years and getting to know each of them, I feel like a proud father!"

The chicks have grown quickly, already quadrupling in size since they were born, and eat a diet of quail, rats, and mice the Ravenmaster provides. The raven parents have an egalitarian feeding arrangement: Huginn, the male, preps the food and passes it to Muninn, the female, who feeds it to her tiny chicks.

The plan is for one of the chicks to stay at the Tower and join the rest of the ravens there. "As the ravens started to hatch on the 23 April, St. George’s Day, the raven that will be staying at the Tower will be called George or Georgina in honor of the occasion," the Tower explained in a press release. According to The Telegraph, the breeding program at the Tower kicked off in response to a decline in the number of legal raven breeders in the UK.

The last raven chick born at the Tower was Ronald Raven, born May 1, 1989. In his 2018 book, The Ravenmaster: My Life with the Ravens at the Tower of London, Skaife wrote that "a baby raven looks a bit like a grotesque miniature gargoyle, but then you see them grow and develop ... It really is wonderful."

The baby ravens born at the Tower of London in 2019
The baby ravens born at the Tower of London in 2019 making some noise
Yeoman Warder Chris Skaife

Dozens of Donkeys, Mini-Donkeys, and Baby Donkeys Are Looking for New Homes

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iStock.com/huggy1

Cats and dogs aren't the only rescue animals that need permanent homes. At the Humane Society of North Texas (HSNT), there are over 60 donkeys, miniature donkeys, baby donkeys, and Thoroughbred horses up for adoption, the Cleburne Times-Review reports.

Many of the equines at HSNT's ranch in Joshua, Texas came from owners who had to give them up, and others were transferred from different animal rescue groups. As part of the ASPCA’s Help A Horse Home Challenge, HSNT is hosting events to help find new homes for its horses and donkeys.

Between April 26 and June 30 this year, the ASPCA is challenging equine organizations to adopt out as many animals as they can. The groups that see the biggest increases in adoptions between this year and last year's Help A Horse Home Challenge will share $150,000 in grant funding. On May 18 and June 8, HSNT is holding open houses at its ranch for anyone interested in adopting an animal. The events will also be used as opportunities to educate the public about the demands of equine ownership.

If you're not free to swing by one of HSNT's open houses, you can still apply to adopt a horse or donkey. Interested owners can fill out and submit this form [PDF] to equine@hsnt.org. And if you'd like to spend time with baby and mini-donkeys without taking one home, HSNT is also looking for volunteers.

[h/t Cleburne Times-Review]

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