Data from: Intraspecific variation among social insect colonies: persistent regional and colony-level differences in fire ant foraging behavior

Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior.

同一物种内的个体在诸多生态相关维度上存在差异，但这类差异的成因与后果往往尚未得到充分阐释。觅食行为是生物体参与的兼具高收益与高风险的活动之一，理论上会受到强烈的自然选择作用。在社会性昆虫中，已有研究表明，诸如觅食行为这类性状的巢内差异可提升蚁群适合度，但不同蚁群间的性状差异及其潜在后果却鲜有记录。本研究以红火蚁（Solenopsis invicta）的自然种群为研究对象，首先验证了其觅食行为在蚁群水平与区域水平上的差异存在性，并检验了这类差异随时间推移以及在不同觅食生境下的稳定性。此外，我们在标准化环境中繁育单谱系蚁群，以探究蚁群谱系对觅食行为的贡献程度。来自自然种群的红火蚁，其觅食行为（包括巢外活动、探索行为、资源发现与资源招募行为）在蚁群与区域水平上均存在显著且稳定的差异。此外，巢外活动的蚁群水平差异与蚁群生长速度显著相关，表明这类差异会对蚁群适合度产生影响。蚁群谱系对巢外活动与探索行为存在显著影响，可解释约半数的觅食行为差异，这意味着蚁群行为的水平差异存在可遗传的组分。