[論文レビュー] 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 Behavior被引用数 0

ひとこと要約

研究は木蛙の群唱の野外録音を分析し、隣接する雄同士の呼び出しの同期が、呼び出し頻度と群唱密度の変動にもかかわらず、距離の関数として徐々に現れることを示す。

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.

研究の動機と目的

• acoust apical 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.

提案手法

• Combined sound-imaging system (25–66 units) and a 16–24 channel microphone array を用いた野外録音。
• 個々の雄について、呼び出し頻度、呼 timing、呼び出し者の位置を抽出するための映像・音声データ分析。
• 全体で66雄を含む11つの群唱を横断した分析。
• 呼び出し間距離に基づく同期（呼び替え）を、異なる頻度と密度の下で評価。

実験結果

リサーチクエスチョン

• RQ1 隣接する雄木蛙間の呼び出し同期は、呼び出し者間の距離の函数として徐々に現れるか。
• RQ2 自然環境における発生は、呼び出し頻度と群唱密度の変動によってどのように影響を受けるか。
• RQ3 自然な木蛙群唱内の呼び出し者の位置とタイミングの時空間パターンとは何か。

主な発見

• 呼び替えの同期的挙動は、距離が近づくにつれて隣接する呼び出し者間で徐々に現れる。
• 呼び出し頻度の moderate な変動と群唱密度にもかかわらず出現する。
• 野生の群唱における空間的接近と時間的調整の定量的な関連を提供する。