Clark Molly A, Waples Ella, Radford Andrew N, Simpson Stephen D, Ioannou Christos C
School of Biological Sciences, University of Bristol, Bristol, BS8 1 TQ, UK.
School of Natural Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
Sci Rep. 2025 May 29;15(1):18801. doi: 10.1038/s41598-025-03225-y.
Group living has essential fitness benefits for many species. While numerous studies have explored how environmental conditions impact collective movement, their impact on decisions made in a social context-a central component of group-living-is poorly documented. In this study, we assess how acoustic noise impacts group decision-making, cohesion and activity in fish shoals, using Trinidadian guppies (Poecilia reticulata) as a model species. Movements within a radially symmetric five-armed maze were measured using high-resolution trajectory data from video-tracking software. The behaviour of groups with and without continuous acoustic white noise were measured over a four-day testing period in a repeated-measures design. We found no significant change in swimming speed or group cohesion with additional acoustic noise. However, there was evidence for fewer following events (moves into already occupied arms) in the noise treatment compared to the control, but this additional noise had no effect on leadership attempts (moves into empty arms). We found strong evidence for consistent, repeatable differences between groups in all behavioural parameters indicating strong personality variation at the group level. Rather than environmental factors, these results provide evidence that consistent group-level differences dominate variation in collective behaviour, including group decision-making, in fish shoals.
群居生活对许多物种具有重要的适应性益处。虽然众多研究探讨了环境条件如何影响集体运动，但环境条件对在社会背景下做出的决策（群居生活的核心组成部分）的影响却鲜有记录。在本研究中，我们以特立尼达孔雀鱼（孔雀花鳉）作为模式物种，评估声学噪声如何影响鱼群中的群体决策、凝聚力和活动。使用视频跟踪软件的高分辨率轨迹数据测量了在径向对称的五臂迷宫中的运动。在重复测量设计中，在为期四天的测试期内测量了有和没有连续声学白噪声的鱼群的行为。我们发现，额外的声学噪声对游泳速度或群体凝聚力没有显著影响。然而，有证据表明，与对照组相比，噪声处理组中的跟随事件（进入已被占据的臂）较少，但这种额外的噪声对领导尝试（进入空臂）没有影响。我们发现有力证据表明，所有行为参数在不同鱼群之间存在一致、可重复的差异，这表明在群体水平上存在强烈的个性差异。这些结果表明，在鱼群中，一致的群体水平差异而非环境因素主导了集体行为（包括群体决策）的变化，而非环境因素。
