Data from: Do small swarms have an advantage when house hunting? The effect of swarm size on nest-site selection by Apis mellifera

Reproductive swarms of honeybees are faced with the problem of finding a good site to establish a new colony. We examined the potential effects of swarm size on the quality of nest-site choice through a combination of modelling and field experiments. We used an individual-based model to examine the effects of swarm size on decision accuracy under the assumption that the number of bees actively involved in the decision-making process (scouts) is an increasing function of swarm size. We found that the ability of a swarm to choose the best of two nest sites decreases as swarm size increases when there is some time-lag between discovering the sites, consistent with Janson & Beekman (Janson & Beekman 2007 Proceedings of European Conference on Complex Systems, pp. 204–211.). However, when simulated swarms were faced with a realistic problem of choosing between many nest sites discoverable at all times, larger swarms were more accurate in their decisions than smaller swarms owing to their ability to discover nest sites more rapidly. Our experimental fieldwork showed that large swarms invest a larger number of scouts into the decision-making process than smaller swarms. Preliminary analysis of waggle dances from experimental swarms also suggested that large swarms could indeed discover and advertise nest sites at a faster rate than small swarms.

蜜蜂繁殖分蜂群面临着寻觅优质新巢址以建立新蜂群的难题。本研究通过建模与野外实验相结合的方式，探究了蜂群规模对巢址选择质量的潜在影响。本研究假设，积极参与决策过程的侦察蜂（scouts）数量随蜂群规模增大而递增，并据此采用基于个体的模型（individual-based model），探究了蜂群规模对决策准确性的影响。研究发现，当两个巢址的发现存在一定时间差时，蜂群选择最优巢址的能力会随蜂群规模扩大而下降，这一结果与Janson与Beekman（2007年《欧洲复杂系统会议论文集》，第204–211页）的研究结论一致。然而，当模拟蜂群面临在所有时段均可被发现的多个巢址间进行选择的现实场景时，由于大型蜂群能够更快速地发现巢址，其决策准确性反而高于小型蜂群。本研究的野外实验结果表明，相较于小型蜂群，大型蜂群会投入更多的侦察蜂参与决策过程。对实验蜂群摇摆舞（waggle dances）的初步分析也显示，大型蜂群确实能够比小型蜂群更快地发现并传递巢址信息。