Every day, this Indian animal starts singing exactly when the Sun is 3.8 degrees below horizon

Platypleura capitata belongs to the broad cicada family (Cicadoidea) and is part of the genus Platypleura, found across India and Sri Lanka. Cicadas are known for their loud and distinctive calls, produced by tiny “drums” called tymbals on their abdomen.

Where and how the chorus was recorded

In April and May 2023, researchers placed recording devices at two sites near Bangalore—one in a shrubland, the other in a bamboo forest, according to a study published in the journal Physical Review E.

The study revealed that every day, these cicadas began their powerful chorus exactly when the Sun was 3.8° below the horizon (file)

These devices, positioned about a meter above the ground, captured the dawn chorus across eight consecutive days at each site, providing a wealth of detailed acoustic data.

The study revealed that every day, these cicadas began their powerful chorus exactly when the Sun was 3.8° below the horizon—during civil twilight, just before sunrise. That moment proved to be consistent, with the midpoint of the chorus’s crescendo landing at nearly the same solar angle day after day

Within roughly one minute, the entire chorus goes from soft emergence to a full symphony, showing a level of synchronisation that’s nothing short of astounding.

“We’ve long known that animals respond to sunrise and seasonal light changes,” co-author Professor Raymond Goldstein from Cambridge’s Department of Applied Mathematics and Theoretical Physics, told the BBC. “But this is the first time we’ve been able to quantify how precisely cicadas tune in to a very specific light intensity – and it’s astonishing.”

Why so exact?

The researchers explored this precision using a model borrowed from physics, akin to how magnetic materials align their spins. In the same way cicadas respond to ambient light, they also listen and react to their neighbours. As light levels reach that exact threshold, each cicada joins in, creating a cascading, collective chorus.

Think of it like a wave of participants at a sporting event; you don’t know exactly when it’ll begin, but once the first few stand, the rest join in, trying not to miss the thrill.

This behaviour is a window into how groups of animals can make highly coordinated decisions using simple environmental cues and local communication. It’s not a conscious coordination; it’s an emergent phenomenon where individuals synchronously respond to both light and their chorus companions

The genus Platypleura spans across Africa and southern Asia, and includes species known to regulate their body temperature (endothermy)—especially those calling during twilight—which allows them to stay active while reducing the risk of predators.