Chorus Organization in a Neotropical Forest Cicada.

Area of Science:

• Animal behavior
• Bioacoustics
• Evolutionary biology

Background:

• Male animals often aggregate and vocalize to attract females.
• Synchronized calling in animal choruses is a common but debated phenomenon.
• Synchronization may arise from collective benefits or male-male competition.

Purpose of the Study:

• Investigate chorus organization in the Emerald cicada (Zammara smaragdula).
• Determine if cicada call rhythm synchronization occurs and explore its evolutionary drivers.
• Examine factors influencing temporal call overlap in cicada choruses.

Main Methods:

• Field observations of Emerald cicada choruses in Belize.
• Analysis of call timing and temporal aggregation patterns.
• Assessment of synchronization based on call intervals and durations.

Main Results:

• Emerald cicada choruses occurred at dawn, dusk, and occasionally during the day.
• No evidence of call rhythm synchronization was found among males.
• Collective calling bouts followed variable quiet intervals, suggesting competitive origins.
• Temporal call overlap varied with chorus phase and time of day.

Conclusions:

• The temporal aggregation of Emerald cicada calls likely stems from male-male competition, not collective benefits.
• Chorus organization shows flexibility, potentially influenced by environmental variables like cicada density, predation, or temperature.