Natal dispersal is a crucial life-history trait that affects both individual fitness and population structure, yet drivers of variation in dispersal probability and distance are difficult to study in wild populations. In cooperatively breeding species, individuals typically delay dispersal beyond their first breeding season and remain on the natal territory as nonbreeders, which prolongs social dynamics that can affect dispersal decisions. Using a 35-year data set covering almost 600 dispersal events in the cooperatively breeding Florida scrub-jay (Aphelocoma coerulescens), we examined the environmental and social parameters that predict dispersal probability over time and distance. In both sexes, dispersal probability increased with age, which, in turn, was negatively correlated with dispersal distance. In males, individuals occupying low-quality natal territories and living with a stepfather had an increased probability of dispersal. Older and more dominant males were more likely to inherit their natal territory. In females, which generally disperse earlier and farther than males, socially subordinate jays dispersed farther than dominant ones. Overall, jays that delayed dispersal the longest were more likely to attain breeding status near their natal territory, which was previously found to be associated with increased survival and lifetime fitness. Our results suggest that social dynamics and environmental factors on the natal territory affect delayed dispersal patterns differently for the two sexes in this cooperative breeder.

中文翻译：

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调查合作繁殖禽类中出生扩散的社会和环境预测因素

纳塔尔散布是一个重要的生活史特征，会影响个体适应度和种群结构，但是在野生种群中很难研究散布概率和距离变化的驱动因素。在合作繁殖物种中，个体通常将扩散推迟到其第一个繁殖季节之后，并以非繁殖者的身份留在本国领土上，从而延长了可能影响扩散决定的社会动力。使用35年的数据集涵盖了合作繁殖的佛罗里达灌丛（Aphelocoma coerulescens）的近600次扩散事件），我们检查了环境和社会参数，这些参数可预测随着时间和距离的扩散概率。在男女中，散布的可能性都随着年龄的增长而增加，这反过来与散布的距离呈负相关。在男性中，居住在出生地质量低下并与继父同住的人散布的可能性增加。年龄较大且占优势的男性更有可能继承其出生地。在女性中，通常比男性散布的早和远，在社会上从属的鸟巢的散布比占主导地位的更远。总体而言，延迟传播时间最长的松鸦更有可能在其出生地附近获得繁殖状态，以前发现这与增加存活率和提高一生的适应能力有关。