Natures wonders: synchronized firefly lights (Introduction)

by David Turell , Tuesday, September 21, 2021, 18:17 (942 days ago) @ David Turell

Some species light up together:

https://aeon.co/essays/how-firefly-flashes-illuminate-the-physics-of-complex-systems?ut...

"While fireflies have been found on every continent except Antarctica, synchronous species are rarer. Early scientists who investigated popular accounts of firefly synchrony often dismissed it as an illusion, a statistical accident, or an observational artefact caused by an observer blinking their eyelids or the fireflies’ light-producing organs being aligned by the wind. As synchronous displays are rare, not to mention complex and ‘messy’, scepticism persisted. Even after precise synchrony was first confirmed in Thailand in 1968, there was no record of the phenomenon in the western hemisphere until the 1990s. It was Lynn Faust – back then a firefly hobbyist, nowadays a world-renowned expert – who was the first to identify synchronous fireflies in the United States, in the backyard of her family’s cabin in Tennessee. Careful studies over the past 50 years have confirmed that synchronous fireflies are more common than originally thought. To date, three species of synchronous fireflies have been found in North America, and we might yet discover many more in the future.

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"Fireflies’ dazzling light displays are, in fact, courtship rituals: flying males announce their presence as suitable mates to the females on the ground. Their light signal is composed of a species-specific on/off light pattern repeated periodically. A good example is Photinus carolinus, a synchronous firefly species documented in the southeast region of the US. A male would fly about a metre off the ground. Every 15 seconds or so, he makes several consecutive flashes, one second apart. The female P carolinus stays closer to the ground in low vegetation. If the female is interested, she waits two seconds before making a half-second flash of her own at the third second.

"Flash production is a voluntary action, resulting from the well-timed release of the neurotransmitter octopamine that then triggers a chemical reaction in the insect’s lantern. The current, state-of-the-art hypothesis is that fireflies control their flashing by regulating how much oxygen goes to their light-producing organs, though whether that’s accurate is still unclear. What’s certain is that, unlike a light bulb, a firefly’s light is ‘cold light’, with only minimal energy lost as heat. This is crucial to fireflies’ survival, as a firefly could not withstand its lantern getting as hot as a light bulb.

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"Our results suggest that fireflies interact locally through a dynamic network of visual connections according to the extent to which they’re separated from surrounding terrain and vegetation. This result illuminates the importance of the environment in shaping self-organisation and collective behaviour. And finally, we showed that information is expressed not only in the timing of the flashes, but also in the movement of the fireflies. Encoding information in movement of the synchronous fireflies is less striking by eye, but our cameras tracked what our naked eye could not: although collective flashing is symmetric within a burst, firefly movement is not. The burst leader was flashing longer and flying farther than followers. Specifically, the pacemaker males who flash earlier in the burst move faster, in comparison with males who flash later throughout the burst."

Comment: And so it is case of follow the leader. Note firefly light takes a special protein. How did this develop in nature because most insects can easily mate without such signaling?