Data from: Growth affects dispersal success in social mole-rats, but not the duration of philopatry

In naked mole-rats (Heterocephalus glaber), some non-breeding males show faster growth and are more likely to disperse than others. These differences have been suggested to be the result of a specialized developmental strategy leading to shorter philopatry and independent breeding, as opposed to extended philopatry as non-reproductive helpers. However, it is unclear whether fast-growing males disperse sooner than slow-growing males. An alternative explanation is that variation in quality between individuals causes high-quality individuals to grow quickly and maximize dispersal success without reducing philopatry. Here we show, that in Damaraland mole-rats (Fukomys damarensis), males that subsequently disperse successfully, grow faster than other non-reproductive males. This pattern is predicted by both hypotheses and does not discriminate between them. However, contrary to the suggestion that faster growth represents a developmental specialisation for early dispersal, fast-growing and slow-growing males remained equally long in their natal groups. Our study provides no evidence for adaptive divergence in male development leading either to early dispersal, or extended philopatry. Instead of representing specialized dispersers, fast-growing males of this species may be high-quality individuals.在裸鼹鼠（Heterocephalus glaber）中，部分非繁殖雄性个体展现出更快的生长速度，且相较于其他个体更倾向于扩散。此前有观点认为，这类差异源于一种特化的发育策略，该策略会缩短恋巢性并促成独立繁殖，而非像非繁殖辅助者那样延长恋巢行为。然而目前仍不清楚生长更快的雄性是否会比生长较慢的雄性更早扩散。另一种解释则是，个体间的质量差异会让高质量个体生长更快，同时在不缩短恋巢性的前提下最大化扩散成功率。本研究针对达马拉兰鼹鼠（Fukomys damarensis）开展分析，结果显示：后续成功扩散的雄性个体，其生长速度快于其他非繁殖雄性个体。这一模式同时符合两种假说的预测，无法区分这两种假说。但与“更快生长是为早期扩散演化出的发育特化策略”这一此前的观点相悖的是，生长较快与较慢的雄性个体在出生地社群中停留的时长并无显著差异。本研究未发现雄性发育存在适应性分化的证据，这类分化要么指向早期扩散，要么指向延长恋巢性。该物种中生长较快的雄性，或许并非特化的扩散者，而是高质量个体。