BBB Destination - Great Smokey Mountains

Now, while it's certainly true the Great Smokey Mountains have much to enjoy any time of the year, in a week or so there's a site to behold that draws thousands of visitors from around the globe: synchronous fireflies.


For the traveler:

The Gatlinburg trolley service will be the sole transportation mode for visitor access during this period; no private vehicles will be allowed. In order to accommodate the public transportation, starting at 5:30 p.m. each night June 8-16, the Elkmont entrance will be closed except to registered campers staying at Elkmont.

The public who visit this area for the purpose of watching fireflies in the dark should recognize this is a natural environment with no other restrooms or other facilities and that the fireflies flashing synchrony becomes more apparent later in the night," said Park Superintendent Dale Ditmanson. "So for those catching the early trolleys, there will be several hours before the fireflies come out," he explained.

It is recommended visitors bring flashlights with red cellophane covers to reduce white light. Coolers and alcoholic beverages are prohibited. Visitors can bring lawn chairs, and carry food and water in backpacks which can fit on their laps in the trolleys; there are no services available. Dogs/pets are not allowed on the trolleys or on the trail.

For the science lover:

During the breeding season in June, groups of hundreds of male fireflies of the species Photinus carolinus fly above the ground for about two hours each evening looking for mates. As they fly, they emit tiny bright flashes in unison. They wink their lights in bursts of four to eight at a rate of two flashes per second, then pause for up to 10 seconds, stopping simultaneously.

The fireflies synchronize their performance with such precision that at least one scientist speculates some form of counting may be involved - a trigger that is activated, perhaps, as the effect of the flash builds up over time.

During the interval, the females of the species - which are far fewer in number - respond from the ground below with flashes that are dim but still clearly visible.

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.