Self‐organizing cicada choruses respond to the local sound and light environment

Abstract

1. Periodical cicadas exhibit an extraordinary capacity for self-organizing spatially synchronous breeding behavior. The regular emergence of periodical cicada broods across the United States is a phenomenon of longstanding public and scientific interest, as the cicadas of each brood emerge in huge numbers and briefly dominate their ecosystem. During the emergence, the 17-year periodical cicada species Magicicada cassini is found to form synchronized choruses, and we investigated their chorusing behavior from the standpoint of spatial synchrony.2. Cicada choruses were observed to form in trees, calling regularly every five seconds. In order to determine the limits of this self-organizing behavior, we set out to quantify the spatial synchronization between cicada call choruses in different trees, and how and why this varies in space and time.3. We performed 20 simultaneous recordings in Clinton State Park, Kansas, in June 2015 (Brood IV), with a team of citizen-science volunteers using consumer equipment (smartphones). We use a wavelet approach to show in detail how spatially synchronous, self-organized chorusing varies across the forest. 4. We show how conditions that increase the strength of audio interactions between cicadas also increase the spatial synchrony of their chorusing. Higher forest canopy light levels increase cicada activity, corresponding to faster and higheramplitude chorus cycling and to greater synchrony of cycles across space. We implemented a relaxation-oscillator-ensemble model of interacting cicadas, finding that a tendency to call more often, driven by light levels, results in all these effects. 5.Results demonstrate how the capacity to self-organize in ecology depends sensitively on environmental conditions. Spatially correlated modulation of cycling rate by an external driver can also promote self-organization of phase synchrony. K E Y W O R D Scicada, citizen science, insect chorus, synchrony, wavelet

Species relationships in the extremes and their influence on community stability

“…Other fields, with which some readers may be more familiar, have very similar notions of synchrony. For instance, synchronous volume fluctuations of insect mating calls can produce large oscillations in the total volume of an acoustic signal [12]. Thus, species relationships, and specifically the degree of synchrony between the population dynamics of different species, are important contributors to the stability of an aggregate community property.…”

Rhythm interaction in animal groups: selective attention in communication networks

“…In addition to such multi-year synchrony, males in one species, Magicicada cassini , align their songs, 1 s ‘buzzes’ with a repetition rate ≈0.2 s −1 , with high precision. Simultaneous recordings at multiple locations in a chorus extending over many hectares showed that synchronous alignment, termed ‘phase coherence’, of the male songs was highest for pairs of locations separated by short distances and fell off as inter-location distance increased [52]. The fall-off with distance was much greater than what would be expected from delays simply reflecting the time for sound transmission, ≈1 s over a 343 m distance.…”

Have artificial lighting and noise pollution caused zoonosis and the COVID-19 pandemic? A review

“…In some areas, bright artificial lighting and persistent high temperatures at night, e.g., due to heat haves or the heat island effects, triggered prolonged singing by cicadas (Fig. 5 ) (Sheppard et al 2020 ). Cicadas are not the only species that exhibit such abnormal behavior.…”