I arrived at my friend’s property in the Macquarie Pass National Park for the New Year period, to a sight I wasn’t expecting. Bodies strewn everywhere, some dead, some half-alive, listless beyond repair. Some lying topsy-turvy on the porch and in the driveway, at the mercy of voracious lizards, snakes, birds and a few other hunters that lurked in this vast and intricate rainforest world.
This scene of carnage – of translucent wings, blood-red eyes, bullet-shaped abdomens and retracted limbs – once belonged to vibrant Yellow Mondays, Black Princes, Green Grocers and Tom Thumbs, cicadas I had grown up with my whole life. And while for me this was not a common scene, it wasn’t until thousands of these creatures began ‘singing’ at a preposterously high-volume that I began to pay them proper attention.
At intervals, this singing became so loud it was impossible to have a conversation. This went on for about 13 seconds (I later timed), then all would be quiet for an equal amount of time until the next din. While cicadas are common in Australia, I couldn’t remember hearing such a rhythmic racket, or seeing so many bodies. It got me thinking, these creatures were louder and more rhythmical than us, yet they didn’t need any scotch.
Just who were these maniacs? How do they get so loud?
After a little investigation, I found out the cicada, particularly the common Australian Green Grocer, is one of the loudest insects in the world. They can hit 120 db, which is 10 decibels louder than a thunderous rock concert – loud enough to cause permanent hearing loss in humans.
Interestingly, they make this cacophonous rattle not by rubbing their legs together, but by both buckling and retracting the muscles in their abdomen. Perhaps not surprisingly, it’s the males who are the boisterous ones, and their hollow abdomen acts as a resonance chamber, further amplifying their sound. Furthermore, cicadas have several curious survival tactics that add to their seemingly maniacal behaviour, one being predator satiation.
Predator satiation is when the cicada emerges (after spending the majority of its life in a dark, narrow burrow slurping tree sap) in such numbers that predators, typically birds and lizards, take more than their fill, while the remaining cicadas can quietly go about their breeding. Sacrifice for the common good. Furthermore, it’s known that some cicadas emerge every 13 and 17 years, during prime intervals, which gives them a mathematically greater chance of survival.
While I was wandering through the forest, I encountered more than a few spent Black Princes and Yellow Mondays, with one speared in the unfortunate crevice of a lizard’s mouth. When I returned, I rejoined the rhythm of our conversations, which were ruled by theirs – 13 seconds of clarity, followed by 13 seconds of vibrating madness. A mating song, I later found out.
Suicide, love and uproar, in the hundreds and thousands.
Perhaps I would emerge after years in a dark tunnel in a fit of madness too, screaming at prime intervals. I wonder what they thought of us?
