Emergence and repeatability of leadership and coordinated motion in fish shoals (Gasterosteus aculeatus)

Studies of self-organising groups like schools of fish or flocks of birds have sought to uncover the behavioural rules individuals use (local-level interactions) to coordinate their motion (global-level patterns). However, empirical studies tend to focus on short-term or one-off observations where coordination has already been established, or describe transitions between different coordinated states. As a result, we have a poor understanding of how behavioural rules develop and are maintained in groups. Here, we study the emergence and repeatability of coordinated motion in shoals of stickleback fish (Gasterosteus aculeatus). Shoals were introduced to a simple environment, where their spatio-temporal position was deduced via video analysis. Using directional correlation between fish velocities and wavelet analysis of fish positions, we demonstrate how shoals that are initially uncoordinated in their motion quickly transition to a coordinated state with defined individual leader-follower...针对鱼群、鸟群这类自组织群体（self-organising groups）的研究，一直致力于揭示个体通过局部交互（local-level interactions）协调群体运动以形成全局模式（global-level patterns）所遵循的行为法则。然而，现有实证研究往往仅关注协调行为已形成的短期单次观测，或是对不同协调状态间的转变过程进行描述。因此，学界对群体中行为法则的形成与维持机制仍缺乏深入认知。本研究以棘鱼（Gasterosteus aculeatus）鱼群为研究对象，探究其协调运动的涌现性与可重复性。研究人员将棘鱼群置于简易实验环境中，通过视频分析（video analysis）推导个体的时空位置（spatio-temporal position）信息。通过结合个体速度间的方向相关性分析与鱼群位置的小波分析（wavelet analysis），本研究证实：初始运动不协调的鱼群可快速过渡至具有明确个体领导者-追随者（leader-follower）关系的协调状态……