Data from: Timing of departure from natal areas by Golden Eagles is not constrained by acquisition of flight skills

The post-fledging dependence period (PFDP), which extends from a fledgling’s first flight out of the nest to its departure from the parents’ territory, is crucial in the lifecycle of birds. During this period, juveniles develop their flight and foraging skills to become fully independent. Despite the importance of this life stage in basic bird ecology and conservation, it remains largely overlooked – notably its link with the acquisition of flight skills. In this study, we modeled the variation in seven proxies describing flight skills of 84 GPS-tracked Golden Eagle juveniles in France between 2016 and 2020. Juveniles had a long but highly variable PFDP, averaging 177.9 (±62.2) days after departure from the nest. This period is divided into two phases: a first phase of rapid increase in flight skills over the first 60 days after departure from the nest, followed by a plateau in which flight skills no longer develop until independence. These results suggest that the full development of flight skills is not a constraining factor during the PFDP and that it is advantageous for juveniles to choose to remain in their natal territory. We posit that parents’ tolerance of fledged juveniles is a type of parental care that may maximize their own fitness by improving the survival of their descendants. In future studies, it may be of interest to investigate the factors that may explain the high variability in the duration of this stage between individuals within the same population.离巢后依赖期（post-fledging dependence period, PFDP）指雏鸟首次离巢飞行至其离开亲代领地的时段，是鸟类生命周期中的关键阶段。在此期间，亚成鸟将逐步精进飞行与觅食技能，最终实现完全独立。尽管该生命阶段在鸟类基础生态学与物种保护领域具有重要意义，但目前仍未得到足够重视，其与飞行技能习得之间的关联更是鲜有研究。本研究针对2016至2020年间法国境内84只经GPS追踪的金雕亚成鸟，以7项表征飞行技能的代理变量为基础，建模分析了其飞行技能的变异特征。金雕亚成鸟的离巢后依赖期时长较长且个体间差异显著，离巢后的平均时长为177.9±62.2天。该时期可划分为两个阶段：离巢后的前60天为飞行技能快速提升的第一阶段，随后进入技能发展停滞的平台期，直至亚成鸟实现独立。研究结果表明，飞行技能的完全发展并非离巢后依赖期内的限制因素，而亚成鸟选择留在出生地领地也具有进化优势。我们提出假说：亲代对已离巢亚成鸟的容忍行为属于一种亲代抚育策略，该策略可通过提升后代存活率来最大化亲代自身的进化适合度。未来可进一步探究同一种群内不同个体间该阶段时长存在显著差异的影响因素，这将具有重要研究价值。