Data from: A comparative approach to cooperative transport in ants: individual persistence correlates with group coordination

When groups of ants work together to carry large objects—called cooperative transport—they must form consensus on a travel direction. In many species, groups are unsuccessful at this decision, and deadlock. In other collective decisions, including nest-site selection in honeybees, individuals’ enthusiasm or recruitment intensity for a given option affects the selection process. A similar mechanism may be important during cooperative transport in ants and may account for coordination differences among species. Results from theoretical models suggest that individuals’ persistence—their reluctance to give up or change their preferred direction—may promote coordination. More persistent individuals formed more successful groups in a theoretical context. As an empirical test of this hypothesis, I examined cooperative transport in four ant species that differ substantially in their group-level coordination, from exceedingly coordinated to rarely successful. I focused on the beginning of transport, evaluating groups’ transitions from uncoordinated to successful. I measured two types of persistence at the individual level—total engagement effort and local engagement time—and I measured group coordination for each species. In one species, I also manipulated persistence by adding a force equivalent to infinitely persistent ants to the existing transport groups. Species with more persistent individuals succeeded more often and formed more coordinated transport groups, with more direct paths. Furthermore, adding two infinitely persistent ants to the existing groups seemed to moderately increase their path directness. These results support the hypothesis that high individual persistence promotes group coordination during cooperative transport, and this study informs the mechanisms of emergent coordination.

当蚁群协同搬运大型物体时——该行为被称为协同运输（cooperative transport）——它们必须就行进方向达成共识。在多数蚂蚁物种中，蚁群无法完成该决策，进而陷入死锁。在其他集体决策场景中，比如蜜蜂的巢址选择，个体对某一选项的积极性或招募强度会影响决策进程。类似的机制或许在蚂蚁的协同运输过程中发挥关键作用，并可解释不同物种间的协调能力差异。理论模型的研究结果表明，个体的坚持性——即不愿放弃或改变自身偏好的行进方向——或可促进群体协调。在理论情境中，个体坚持性越强，蚁群的运输成功率越高。为对该假说开展实证检验，本研究选取了4种在群体协调能力上差异显著的蚂蚁——从协调性极强到几乎无法完成运输的物种均有覆盖——对其协同运输行为进行观察。本研究聚焦于运输启动阶段，评估蚁群从不协调状态向成功运输状态的转变过程。研究从个体层面量化了两类坚持性指标：总参与投入与局部停留时长，并针对每个物种测定了其群体协调能力。针对其中一个物种，本研究还通过向现有运输蚁群中加入相当于“无限坚持”个体的外力，对其坚持性进行了操控。个体坚持性更强的物种，其运输成功率更高，且形成的运输群体协调性更强，行进路径也更为笔直。此外，向现有蚁群中加入2只“无限坚持”的个体，似乎可适度提升其行进路径的笔直度。上述结果验证了“个体高坚持性可促进协同运输过程中的群体协调”这一假说，本研究也为涌现性协调的内在机制提供了新的认知。