Data from: Developmental stress predicts social network position

The quantity and quality of social relationships, as captured by social network analysis, can have major fitness consequences. Various studies have shown that individual differences in social behaviour can be due to variation in exposure to developmental stress. However, whether these developmental differences translate to consistent differences in social network position is not known. We experimentally increased levels of the avian stress hormone corticosterone (CORT) in nestling zebra finches in a fully balanced design. Upon reaching nutritional independence, we released chicks and their families into two free-flying rooms, where we measured daily social networks over five weeks using passive integrated transponder tags. Developmental stress had a significant effect on social behaviour: despite having similar foraging patterns, CORT chicks had weaker associations to their parents than control chicks. Instead, CORT chicks foraged with a greater number of flock mates and were less choosy with whom they foraged, resulting in more central network positions. These findings highlight the importance of taking developmental history into account to understand the drivers of social organization in gregarious species.

通过社会网络分析（social network analysis）所表征的社会关系数量与质量，可对个体适合度产生显著影响。多项研究已证实，社会行为的个体差异可能源于发育应激暴露水平的差异。然而，这类发育层面的差异是否会转化为社会网络位置上的稳定差异，目前尚不明确。本研究采用完全平衡实验设计，通过人工手段提升了斑胸草雀雏鸟体内的鸟类应激激素——皮质酮（corticosterone, CORT）的含量。当雏鸟达到营养独立阶段后，我们将幼鸟及其亲代种群释放至两间自由飞行笼舍中，利用被动集成应答器标签（passive integrated transponder tags）连续五周每日记录社会网络数据。发育应激对社会行为存在显著影响：尽管皮质酮处理组雏鸟与对照组雏鸟的觅食模式并无显著差异，但前者与亲代的关联强度显著弱于后者。与之相对，皮质酮处理组雏鸟的觅食同伴数量更多，且对觅食对象的选择更为宽松，最终占据了社会网络中更为核心的位置。本研究结果凸显了在解析群居物种种群社会组织的驱动机制时，考量个体发育历程的重要性。