One of the greatest shows on earth is all about light

Words Tamara Batshon

We all love a great light show – whether we are viewing spectacular fireworks or a laser show at a concert venue – as there is something magical about a symphony of lights in the dark. However, when we are able to see a light display in nature and produced entirely by living things, the experience has a whole new dimension. The performers at the world’s most stunning natural light show are the Elkmont fireflies of Great Smokey Mountain National Park in the American state of Tennessee.

Nature’s Light Show
In an area surrounded by forests straddling the border between North Carolina and Tennessee is the habitat of one of the earth’s most rare species of synchronous fireflies. The Elkmont firefly (Photinus carolinus) is one of 19 species of fireflies in the park and the only one that is synchronous, meaning that they all light up at once and in a dramatic wave effect. No doubt people flock to this national park – which is America’s most visited known for its diversity of plant and animal life – to see this phenomenon during the mating season of the fireflies, which only occurs during a two-week period, usually in the late spring.

The park has to actually limit the nighttime access to Elkmont during this fourteen-day period and can only allow up to 8,000 people to enjoy this outdoor spectacle. Visitors usually bring their own folding camp chairs and blankets so that they can sit back and enjoy the show. In fact, reservations can be made six months in advance and parking permits are even distributed via a lottery. The insects usually start their light signals when it is totally dark (around 9:30p.m.), beginning with the males in short random bursts from six to eight times for about eight seconds before the night goes pitch black. Then this cycle starts all over again until it ends at about midnight. The fireflies’ blinking produces a ripple effect resembling Christmas lights.

Light up to find your mate
When you visit to see the Elkmont fireflies, you’re actually watching these lightning bugs in their annual mating ritual. The fireflies glow in the dark, each with a specific flashing pattern. Female fireflies don’t do too much flying, and they stay near the ground, so the males are usually the ones lighting up the sky. When a female becomes interested in a male, she will blink back from the ground.

It all starts when the females lay their eggs on the ground. When the larvae hatch, they nestle into the soil, feeding on the organic matter, such as decomposed leaves. This larvae period can last for one to two years until they transform into adult fireflies. Once they reach maturity, they only live for about twenty days, which means that they must mate during this brief period. So the brighter the male the better the chances of reproduction. Generally the males flash as they fly around while the females remain on the ground and respond with a fainter double flash that has no set interval. The response allows the males to see the females on the ground so that they can fly down for mating. Experts believe that the females need lots of light to respond back, which is why the males flash in synchrony to get their utmost attention.

Generally fireflies can be found in all sorts of habitats, from wooded areas to open fields but the synchronous lighting types are truly rare. Photinus carolinus exists throughout the southern Appalachians in the United States, but they seem to be the most populous in the Great Smokey Mountain National Park.