Watching a whole forestful of fireflies flashing together in unison is a truly mesmerizing experience. As I described in an earlier post, males of only a few firefly species are capable of this remarkable feat. Although we still don’t know why this behavior occurs, some researchers at the University of Colorado – Boulder recently developed cool tools to shed new light on how fireflies accomplish this collective behavior.
Using Go-Pro cameras to film Photinus carolinus in the Great Smoky Mountains National Park, Raphael Sarfati and Orit Peleg were later able to reconstruct the 3D flight paths of individual male fireflies. You can read about their study in this month’s Smithsonian Magazine, or check out their original paper in the Journal of the Royal Society Interface.
Their findings provide clues into how insects with relatively small brains can perform such seemingly complex synchronous behaviors. By demonstrating how fireflies kick off their synchrony, this research will inspire new advances in swarm robotics. In the future, their tracking methods could also be adapted for community science projects like Firefly Watch in the U.S. to help scientists monitor long-term trends in firefly populations.
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?
Every June, fireflies light up the Smoky Mountains with their exuberant courtship displays – sure, it all seems very romantic. But a few years ago I spent some weeks with colleagues studying the predators that take advantage of these dense breeding aggregations. We knew that certain insectivores – like birds and lizards – avoid eating fireflies because they’re toxic. So we didn’t expect to find many predators enjoying this luminous feast. Little did we realize how gore-filled that summer would turn out to be!*
* You can read our Dark Side paper here: Lewis, S.M., L. Faust, and R. De Cock. 2012. The Dark Side of the Light Show: Predators of Fireflies in Great Smoky Mountains. Psyche, 634027.
Following a summer of scorching drought, wildfires have ravaged parts of the southeastern United States. Last month, a devastating fire burned out of control through Gatlinburg, Tennessee.
Chimney 2 forest fire burns in the Smoky Mountains (Nov 2016)
From its starting point in the Great Smokies National Park, the fire exploded into an inferno fanned by strong winds. For days, hundreds of firefighters battled the blaze. The Sevier County mayor called the combination of wind and dry tinder a “once-in-a-lifetime event…a perfect storm.” By the time they finally extinguished the fire, the charred landscape stretched across 17,500 acres. Fourteen people lost their lives, and nearly 200 were injured. Tens of thousands were forced to evacuate, and over 2400 homes and businesses were destroyed.