Synchronous fireflies certainly highlight Earth’s natural magic, yet such cooperative behavior presents quite a thorny scientific paradox!
We do know how some fireflies manage to synchronize their flashing, thanks to work done in the 1960’s by John & Elisabeth Buck (previous post). For instance, male Pteroptyx fireflies in southeast Asia can reset their internal timekeeper whenever they see a neighbor’s flash. Inspired by Steve Strogatz’s book, Sync, Nick Case made a spectacular simulation to illustrate how this works – I’ve played with it for hours, and you can, too!
Synchronous fireflies in the Great Smoky Mountains
But why do fireflies synchronize? Why should thousands of males so carefully coordinate their behavior to flash in unison, all of them marching to the beat of a single drummer? According to sexual selection theory, these males should be competing fiercely with each other for the chance to mate. So why synchronize?
From Joanne, in Wisconsin –
About 15 years ago we held a family reunion near a small lake in the Blue Ridge Mountains, near Saluda, NC. It was around July 4th, so around the lake lots of people were setting off fireworks. We were gathered by the lake near a wide grassy area that led right up to the base of the mountain. That night the fireflies appeared around dusk, just when the fireworks started. Although the fireworks were going off much higher up, we realized that down below the fireflies’ flashing was gradually getting synched up with the fireworks. As it got darker, the coordination seemed to increase so that every time a firework went off, the fireflies would light up, all pretty much at the same time.
It was a magical scene – a constellation of yellow-green flashes lighting up down near the ground, triggered by the dramatic firework explosions in the sky. And the fireflies earned much bigger “ooooohs!” than the fireworks! Only later did I learn that what we were seeing were probably the romantic signals of male Photinus carolinus fireflies, flashing together like one big mega-male to try to win the favor of their females.
Stop what you’re doing and watch this short video taken in Samut Prakan province, Thailand. Turn off the lights, go full screen, and get ready to be blown away by thousands of male fireflies regularly synchronizing their flashes to attract females. They synchronize naturally, although here the fireflies (known as Pteropytx malaccae) have been triggered by some flashing LED lights. This video is part of a 2015 installation work by Robin Meier & Andre Gwerder, it’s called “Synchronicity (Thailand).”
You can also watch some spectacular displays of the U.S. synchronous firefly, Photinus carolinus, which lives parts of North Carolina, Tennessee, and Pennsylvania. You can read more about these traveling synchronizers in Silent Sparks (Chapter 2: Lifestyles of the Stars).
Produced by Audemars Piguet Art Commission, Le Brassus
Director of Photography: Nikolai Zheludovich; Editing: Mariko Montpetit
Special thanks to Anchana Thancharoen and her team at Kasetsart University, Bangkok