TY - JOUR T1 - Self-organization in natural swarms of <em>Photinus carolinus</em> synchronous fireflies JF - bioRxiv DO - 10.1101/2021.01.26.428319 SP - 2021.01.26.428319 AU - Raphaƫl Sarfati AU - Julie C. Hayes AU - Orit Peleg Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/01/27/2021.01.26.428319.abstract N2 - Fireflies flashing in unison is a mesmerizing manifestation of animal collective behavior and an archetype of biological synchrony. To elucidate synchronization mechanisms and inform theoretical models, we recorded the collective display of thousands of Photinus carolinus fireflies in natural swarms, and provide the first spatiotemporal description of the onset of synchronization. At low firefly density, flashes appear uncorrelated. At high density, the swarm produces synchronous flashes within periodic bursts. Using three-dimensional reconstruction, we demonstrate that flash bursts nucleate and propagate across the swarm in a relay-like process. Our results suggest that fireflies interact locally through a dynamic network of visual connections defined by visual occlusion from terrain and vegetation. This model illuminates the importance of the environment in shaping self-organization and collective behavior.Competing Interest StatementThe authors have declared no competing interest. ER -