Data from: Does the history of option quality affect nest site choice in the acorn ant?

During decision−making, animals consider not only the current but also the past quality of options. For example, when humans evaluate performance (e.g. sales) of employees, they do not only consider the average performance but also the trend of performance ascending performance is often viewed as more favorable than descending performance. In our study, we test if non-human animals have a similar bias when they are evaluating options using house-hunting by the acorn ant, Temnothorax curvispinosus, as our model system. Our data show that when nest-site quality is static over time, ant colonies tend to prefer the nest site which was better (i.e. darker) between two nest options. However, when the nest quality changes—one improves and the other worsens—over time, more colonies choose the low-quality, but improving, nest than the high-quality, but worsening, nest. These results suggest that a continuous change of option quality may influence evaluation. We discuss alternative explanations for our results, possible mechanisms and potential ecological benefits for keeping track of the nest-site quality.

在决策行为中，动物不仅会考量选项当下的品质，还会兼顾其过往表现。例如，人类在评估员工的绩效（如销售额）时，不仅会考量平均业绩水平，还会关注绩效的变化趋势——业绩呈上升趋势的表现往往比下滑趋势更受青睐。本研究以弯脊切叶蚁（Temnothorax curvispinosus）的巢址选择行为作为实验模式系统，探究非人类动物在评估选项时是否存在类似的决策偏差。实验数据显示，当两个巢址的品质随时间保持恒定时，蚁群通常会更青睐二者中原本品质更优（即更阴暗）的巢址。但当巢址品质随时间发生变化——一个巢址品质提升、另一个下降时，选择低品质但持续改善的巢址的蚁群数量，要多于选择高品质但持续恶化的巢址的蚁群。上述结果表明，选项品质的持续变化可能会对评估过程产生影响。本研究还讨论了针对该实验结果的多种替代性解释、潜在作用机制，以及持续追踪巢址品质可能带来的生态益处。