Data from: Who directs group movement? Leader effort vs follower preference in stickleback fish of different personality

During collective movement, bolder individuals often emerge as leaders. Here, we investigate whether this reflects a greater propensity of bold individuals to initiate movement, or a preference for shy individuals to follow a bolder leader. We set up trios of stickleback fish comprising a focal individual who was either bold or shy, and one other individual of each personality. We then recorded the movements of all individuals in and out of cover in a foraging context to determine how assiduously the focal fish followed the movements of each other partner. We found that a shy focal fish preferred to follow a leader whose personality matched its own, but we did not detect such a difference in bold fish. Despite this preference, however, the greater propensity of bold individuals to initiate movements out of cover meant that they successfully led more joint trips. Thus, when offered a choice of leaders, sticklebacks prefer to follow individuals whose personality matches their own, but bolder individuals may, nevertheless, be able to impose their leadership, even among shy followers, simply through greater effort.

在集体移动过程中，性格更为大胆的个体往往会成为群体领导者。本研究旨在探究这一现象究竟源于大胆个体更具发起移动的倾向性，还是害羞个体更偏好追随大胆领导者。我们设置了由3尾棘鱼组成的实验组合：每组包含1尾性格为大胆或害羞的目标个体，以及另外2尾分别对应两种性格的同伴。随后，我们在觅食场景下记录了所有个体进出遮蔽处的行为，以此评估目标个体追随其余同伴移动的投入程度。实验结果显示，性格害羞的目标个体更偏好追随与自身性格匹配的领导者，而大胆的目标个体则未表现出此类偏好差异。尽管存在上述偏好，但由于大胆个体发起移动、离开遮蔽处的倾向性更强，因此它们成功主导了更多的集体移动活动。综上，当存在多个领导者可供选择时，棘鱼更倾向于追随与自身性格匹配的个体；但即便面对害羞的追随者，大胆个体仍可凭借更高的行为主动性，确立自身的领导地位。