[Paper Review] Gradual emergence of temporal structures depending on the distance between neighboring callers in natural habitat of male treefrogs

Ikkyu Aihara, Ryu Takeda+4 more|arXiv (Cornell University)|Mar 17, 2026

Animal Vocal Communication and Behavior0 citations

TL;DR

The study analyzes field recordings of treefrog choruses to show that call synchronization between neighboring males gradually emerges as a function of their distance, despite variations in call frequency and chorus density.

ABSTRACT

Acoustic animals (e.g., insects and frogs) aggregate and produce sounds for mating. Well-organized chorus structures like call alternation and call synchrony indicate the importance of the precise control of call timing by individual males. However, the stable monitoring of multiple acoustic features in natural environments, especially the variation in call frequency, call timing and caller position, lacked in previous studies because of technical difficulties originating from the intense background noise, the existence of multiple sound sources and the wide area for monitoring. Here we have examined the spatio-temporal frequency structure in the choruses of wild treefrogs. First, we have performed field recordings by combining the sound-imaging system (25-66 units of sound-imaging devices) and microphone-array system (16-24ch of microphones) between 2021 and 2023. Second, we have analyzed the video and audio data and quantified the call frequency, call timing and caller position of each male, for 11 choruses with 66 males in total. Based on this large datasets, we have shown that synchronized behavior (call alternation) gradually emerges between neighboring callers depending on their distances even when the call frequency and chorus density moderately vary.

Motivation & Objective

• Motivate understanding of how temporal coordination emerges in acoustic animal communities.
• Quantify spatio-temporal call features (frequency, timing, and caller position) in natural treefrog choruses.
• Assess how distance between neighboring callers influences synchronization patterns under varying chorus density.

Proposed method

• Field recordings using a combined sound-imaging system (25–66 units) and a 16–24 channel microphone array.
• Video and audio data analysis to extract call frequency, call timing, and caller position for individual males.
• Analysis performed across 11 choruses comprising 66 males in total.
• Assessment of synchronization (call alternation) as a function of inter-caller distance under varying frequencies and densities.

Experimental results

Research questions

• RQ1 Does call synchronization between neighboring male treefrogs emerge gradually as a function of distance between callers?
• RQ2 How do variations in call frequency and chorus density affect the emergence of temporal structures in natural habitats?
• RQ3 What are the spatio-temporal patterns of caller positions and timing within natural treefrog choruses?

Key findings

• Synchronized behavior in call alternation gradually emerges between neighboring callers as distance decreases.
• Emergence occurs despite moderate variability in call frequency and chorus density.
• The study provides a quantitative link between spatial proximity and temporal coordination in wild choruses.