Each June in the Elkmont area of the Great Smoky Mountains, a natural phenomenon occurs that continues to baffle scientists.
During a two week window in late spring, thousands of lightning bugs flash in complete unison.
The synchronous firefly show, which researchers have identified as a rare form of “simultaneous bioluminescence”, is a popular and growing attraction for the Smoky Mountains. Each evening, several hundred park visitors begin arriving in Elmont with blankets, chairs and flashlights to witness the natural phenomenon that occurs after the park becomes pitch black.
To get an idea of just what happens, check out this YouTube video. The video is a little grainy, but it still gives you a rough idea of what you can expect to see:
Although the existence of synchronous fireflies at Elkmont was known to only a few prior to the early 1990s, synchronous fireflies have been known to visitors of Southeast Asia for centuries. In fact, Sir Francis Drake recorded the phenomenon during his exploration of the East Indies in 1577.
While Elkmont has become a popular and crowded spot to see the lightning bugs, similar glow-in-the-dark shows have also been reported in Cades Cove, Joyce Kilmer-Slickrock Wilderness Area, Hot Springs, Greenbrier and the Sugarlands in recent years.
Synchronous fireflies (Photinus carolinus) are one of 14 species of fireflies that live within the park boundaries. They’re the only species in America whose individuals can synchronize their flashing light patterns.
Fireflies take from one to two years to mature from larvae, but will live as adults for only about 21 days. Their light patterns are part of the adulthood mating display. Each species of firefly has a characteristic flash pattern that helps its male and female individuals recognize each other. The males fly and flash and the usually stationary females respond with a flash.
No one is quite sure why the fireflies flash synchronously. Competition between males may be one reason: they all want to be the first to flash. Or perhaps if the males all flash together they have a better chance of being noticed, and the females can make better comparisons. The fireflies do not always flash in unison. They may flash in waves across hillsides, and at other times will flash randomly. Synchrony occurs in short bursts that end with abrupt periods of darkness.
Peak flashing for synchronous fireflies in the park normally occurs within a two-week period in mid-June.
As in recent years, in order to control the crowds, the park will close the road to Elkmont (except to registered campers staying at Elkmont), and a trolley service from the Sugarlands Visitor Center will be provided for those wishing to see the fireflies in action.
Trolleys will run between the Sugarlands Visitor Center and Elkmont on June 6-14 from 6:00 p.m. to 9:00 p.m. (but will end earlier in the evening if the parking lot fills up). The last trolley back to the Visitor Center will leave Elkmont at 11:00 p.m.
For more information call the Park at 865-436-1200.