Data from: Microgeographic socio-genetic structure of an African cooperative breeding passerine revealed: integrating behavioural and genetic data.

Dispersal can be motivated by multiple factors including sociality. Dispersal behaviour affects population genetic structure that in turn reinforces social organization. We combined observational information with individual-based genetic data in the Karoo scrub-robin, a facultative cooperatively breeding bird, to understand how social bonds within familial groups affect mating patterns, cause sex asymmetry in dispersal behavior and ultimately influence the evolution of dispersal. Our results revealed that males and females do not have symmetrical roles in structuring the population. Males are extremely philopatric and tend to delay dispersal until they gain a breeding position within a radius of two territories around the natal site. By contrast, females dispersed over larger distances, as soon as they reach independence. This resulted in male neighbourhoods characterized by high genetic relatedness. The long-distance dispersal strategy of females ensured that Karoo scrub-robins do not pair with relatives thereby compensating for male philopatry caused by cooperation. The observed female-biased strategy seems to be the most prominent mechanism to reduce the risk of inbreeding that characterizes social breeding system. This study demonstrates that tying together ecological data, such as breeding status, determining social relationships with genetic data, such as kinship, provides valuable insights into the proximate causes of dispersal, which are central to any evolutionary interpretation.扩散行为的驱动因素多种多样，社会性亦是其诱因之一。扩散行为可塑造种群遗传结构，而该结构又会反过来强化种群的社会组织模式。本研究以兼性合作繁殖鸟类卡鲁灌丛鸲（Karoo scrub-robin）为研究对象，整合观测数据与个体水平遗传数据，旨在解析家族群体内的社会联结如何影响交配模式、引发扩散行为的性不对称性，并最终作用于扩散行为的演化历程。研究结果显示，雌雄个体在种群结构塑造过程中所承担的角色并不对称。雄性具有极强的恋巢性（philopatric），通常会延迟扩散，直至在出生地周边两个领地的范围内获取繁殖席位。与之相对，雌性一旦达到独立状态便会进行长距离扩散。这使得雄性聚居区呈现出高度的遗传亲缘相关性。雌性的长距离扩散策略确保卡鲁灌丛鸲不会与亲属交配，从而抵消了合作繁殖引发的雄性恋巢行为所带来的近交风险。这种以雌性为主导的扩散策略，似乎是降低合作繁殖体系下近交风险的最关键机制。本研究表明，将繁殖状态等生态数据、亲缘关系等遗传数据与社会关系判定相结合，能够为解析扩散行为的近因提供宝贵视角，而这正是所有演化解读的核心所在。