The juvenile period is a challenging life-history stage, especially in species with a high degree of fission–fusion dynamics, such as bottlenose dolphins, where maternal protection is virtually absent. Here, we examined how juvenile male and female bottlenose dolphins navigate this vulnerable period. Specifically, we examined their grouping patterns, activity budget, network dynamics, and social associations in the absence of adults. We found that juveniles live in highly dynamic groups, with group composition changing every 10 min on average. Groups were generally segregated by sex, and segregation was driven by same-sex preference rather than opposite-sex avoidance. Juveniles formed strong associations with select individuals, especially kin and same-sex partners, and both sexes formed cliques with their preferred partners. Sex-specific strategies in the juvenile period reflected adult reproductive strategies, in which the exploration of potential social partners may be more important for males (which form long-term alliances in adulthood) than females (which preferentially associate with kin in adulthood). Females spent more time alone and were more focused on foraging than males, but still formed close same-sex associations, especially with kin. Males cast a wider social net than females, with strong same-sex associations and many male associates. Males engaged in more affiliative behavior than females. These results are consistent with the social bonds and skills hypothesis and suggest that delayed sexual maturity in species with relational social complexity may allow individuals to assess potential associates and explore a complex social landscape without the risks associated with sexual maturity (e.g., adult reproductive competition; inbreeding).

中文翻译：

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幼年社会动态反映了宽吻海豚的成年繁殖策略

幼年期是一个具有挑战性的生命史阶段，特别是在具有高度裂变融合动力学的物种中，例如宽吻海豚，在那里几乎没有母体保护。在这里，我们研究了幼年雄性和雌性宽吻海豚如何度过这个脆弱时期。具体来说，我们在没有成年人的情况下检查了他们的分组模式、活动预算、网络动态和社会关联。我们发现青少年生活在高度动态的群体中，群体组成平均每 10 分钟改变一次。群体通常按性别隔离，隔离是由同性偏好而不是异性回避驱动的。青少年与特定的个体，尤其是亲属和同性伴侣形成了强烈的联系，两性都与他们偏爱的伴侣形成了派系。青少年时期的特定性别策略反映了成年生殖策略，其中对潜在社会伙伴的探索对男性（成年后形成长期联盟）可能比女性（成年后优先与亲属交往）更重要。与男性相比，女性花更多的时间独处，更专注于觅食，但仍形成密切的同性联系，尤其是与亲属。男性比女性拥有更广泛的社交网络，有强烈的同性交往和许多男性同事。男性比女性从事更多的从属行为。