It's all about the creek…and the mountains

Fairy Dances at Great Smoky Mountains National Park

synchronous fireflies

Synchronous Fireflies Doing Their Thing...

Perhaps you’ve heard of the dance of the fireflies that occurs in Great Smoky Mountains National Park (GSMNP) every springtime. The park is home to a unique species of firefly called Photinus carolinus, or the “synchronous firefly”.  During the mating season in late spring, the males and females engage in a mating ritual—some call it “the fairy dance” – where it appears that the fireflies are blinking in unison.  This light show attracts thousands of visitors to Great Smoky Mountains National Park, and specifically to the Cataloochee Valley area at the east end of the park. 

The fireflies are at the height of their mating and their flashing activity is at its peak during a two-week period between mid-May and mid-June.  On cool nights (below 50º Fahrenheit) and on misty evening following rain, the flashing may be greatly reduced or altogether absent.  The GSMNP posts the dates online and thousands of visitors, flashlights in hand, descend upon the area of the Cataloochee valley for the lightshow.  

If you’d like to add this to your bucket list of must-see events here in our little corner of the mountains, here’s some helpful hints on the when/how/where of the GSMNP “fairy dance”.

First, and most importantly, let’s review some do’s and don’ts for visitors: 

Light Show Etiquette
Flashlights disrupt the fireflies and impair people’s night vision. The light show is best when you:
– Cover your flashlight with red or blue cellophane. 
– Use your flashlight only when walking to your viewing spot.
– Point your flashlight at the ground.|
– Turn off your flashlight when you find your viewing spot.

You can also help protect the fireflies and their habitat:
– Do not catch the fireflies.
– Stay on the trail at all times.
– Pack out all of your garbage.

If you go…
It is essential that you seek out official, detailed information about visiting Great Smoky Mountains National Park in order to see the synchronous fireflies by going to their website.  A lottery system has been put in place to manage the flow of visitors heading to the park within a short two-week period.  

synchronous fireflies
synchronous fireflies

Here’s a bit more of the science and entomology of these unique fireflies (from Wikipedia)…
“Photinus carolinus was the first North American species found to show synchronized flashing behavior. Synchronized flashing by male fireflies is common in South Asia, where huge aggregates of males perch on specific trees to create a bright display of flashing. The synchronized flashing of P. carolinus males occurs in aggregates of flying fireflies.  The timing of flashing depends somewhat on temperature, but the flash pattern of a male P. carolinus is typically four to eight very bright flashes emitted over two to four seconds, followed by a dark period of eight to 12 seconds. The female reply is much less bright, a pulsed signal during the dark period of the male. Scientists have suggested one reason for the synchronized flashing is to create a synchronized dark period, during which males can search for female responses without being distracted by signals from other males.”

But whatever the reason, the result of their mating is the dazzling light show
displayed by their synchronized flashing.