The Synced-Up Fireflies of the Great Smoky Mountains

Dollywood’s just down the road, but for two weeks every summer, the gaudiest show for miles around can be found deep in the woods

Last month, I saw something spectacular, something I’d only heard about a few months before—a forest filled with fireflies blinking together in a pile-up of crazy patterns, like several different bunches of Christmas lights gone haywire.

It was an amazing sight—but one that my camera, unfortunately, wasn’t up to the challenge of capturing. As always, YouTube comes through in the clutch. Check them out here and here to get an idea of what it was like.

Unlike garden-variety fireflies, whose males flash their patterns without seeming to pay attention to the males around them, the species we saw, Photinus carolinus, has a lot more team spirit. Although to the untrained eye they don’t look physically any different that those you may be lucky enough to have in your backyard right now, P. carolinus likes to blink together. Typically, one firefly starts and then other males join in, in a mate-finding game of follow the leader.

But why? It’s still a bit of a mystery. It might be that the synchronized flashing helps females home in on the males that are nearest to them, since otherwise all that would result from all that visual noise is chaos. The synchrony might also help P. carolinus females locate the males of their species, since the Great Smokies have at least nineteen other species of lightning bugs, and that’s a lot of irrelevant options to sift through.

Although other synchronized firefly species have been documented for many years in places like Malaysia, Thailand, and Indonesia, those in the Smokies were virtually unknown until the early 1990s, when a local resident brought them to the attention of Jonathan Copeland, a professor of biology at the Georgia Southern University. He was initially skeptical that synchronous behavior existed in the Smokies as well as southeast Asia, but was soon convinced.

Locals (like the tipster) had been taking in the light show from their cabins and backyards for many years, but it only became common knowledge after Professor Copeland published his findings in 1995.

Every year after, the crowds heading to the Smoky Mountains have grown larger and larger. Although similar light shows exist in other parts of the eastern United States, the Great Smoky Mountains’ population of P. carolinus is probably the largest—and it’s definitely the most well-known.

And that’s what brought us heading toward the park that June evening, at a time when people are usually headed back down to the touristy delights of Gatlinburg and Pigeon Forge. Getting to the fireflies wasn’t really that different from seeing any other major concert or festival—it took a bit of waiting. First, after an enormous early-bird dinner that featured several huge sweet teas and way too much fried chicken and fritters, we drove to the Smoky Mountains’ Sugarland Visitor Center, where we and the other firefly fans lined up patiently for shuttle buses to take us up into the woods, our picnic blankets and lawn chairs (and maybe a little wine) in tow.

After about a half-hour on the bus, we got out in the Elkmont area and were given a short briefing that included the loan of a piece of colored plastic to put over our flashlights to help keep the fireflies from being distracted.

There probably aren’t too many signs like this.

Then we set off for a walk down the main road, trying to head out as long we could to get away from the crowds. In the end, it turned out to not be that important—there was plenty of woods for everyone. Once we got settled and found our snacks, it was time to chill for a while, because these fireflies don’t start blinking until it’s almost completely dark.

The many other people there were a little distracting at first—I’m looking at you, chattering college kids and women busily fidgeting with your fancy camera on a tripod—but everyone quieted down as soon as dark finally came.

By then it was showtime, and the whole forest got quiet. And lit up.

Want to go yourself?

The flashing occurs for only two weeks or so, usually starting around late May. Because of this short window, and because it happens in what’s the most-visited national park in the US, getting here takes some planning and a little hassle. Still, I thought it was more than worth it.

Many people come and camp in Elkmont during this time specifically to see the fireflies. If you’re not up for that, you’ll need to get a parking pass ahead of time, or you won’t be allowed in the park at night. The passes go on sale a couple months before the show—this year they were available starting in late April—and they usually sell out, so plan ahead.

And although there didn’t seem to be any mosquitoes to speak of when we went, we were probably just lucky: definitely load up on repellent. And be ready to be impressed.