A widespread hypothesis for the ontogeny of behavior and decision-making is the early-exploration-later-canalization hypothesis. It postulates that juveniles are more exploratory and adults more consistent in their behavior. In addition, it is often assumed that naïve juveniles could overcome the costs of individual experience building by copying more the decisions of others than adults (early-conformism-later-self-defining hypothesis). Here, we compare the central place foraging movements of adults and postfledging juveniles in their first flights around the colony before dispersal and migration in two sympatric species of tropical seabirds: red-footed boobies and great frigatebirds. Using GPS records of individual movements, we analyzed the foraging directions of seabirds from the colony across successive trips. Juveniles of both species showed significant within-individual consistency in foraging direction but at lower levels than adults. Juveniles leaving the colony within the same time window showed significant but low between-individual resemblance in foraging direction at levels similar to adults. In both species, homing efficiency was lower in juveniles than in adults. Juvenile foraging directions were initially influenced by wind conditions, particularly in low wing loading frigatebirds. Wind conditions progressively lost influence on juvenile foraging directions during their first weeks of flights. In contrast, within-individual consistency, between-individual resemblance, and homing efficiency did not show signs of progression in juveniles. Our results support the early-exploration-later-canalization hypothesis but not the early-conformism-later-self-defining hypothesis. Relaxed constraints on self-feeding efficiency could favor high variability in postfledging tropical seabirds. Our simple approach could be applied to further test these hypotheses by comparing strategies across a wide range of central place foragers.

中文翻译：

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首次探索：两只热带海鸟中心地带觅食方向的个体发育

行为和决策的个体存在的一个广泛的假设是早期探索后运河化假设。它假定青少年更具探索性，成年人的行为更加一致。此外，通常认为，幼稚的青少年可以通过复制比成年人更多的其他决定来克服个人经验积累的成本（早期循规蹈矩后来自我定义的假设）。在这里，我们比较了成年幼体和后生幼体在殖民地的第一次飞行中的中心位置，然后它们在两种同伴的热带海鸟物种：红脚bo鸟和大型护卫鸟的散布和迁移中进行了散布和迁移。利用个人运动的GPS记录，我们分析了连续旅行中来自殖民地的海鸟的觅食方向。这两个物种的幼虫在觅食方向上均表现出明显的个体内一致性，但水平低于成年。在同一时间范围内离开殖民地的少年在觅食方向上显示出显着但个体之间的相似性，但水平很低，与成年人相似。在这两个物种中，少年的归巢效率均低于成年。幼年觅食的方向最初受风的影响，特别是在低翼载护卫舰上。在飞行的最初几周，风势逐渐失去了对幼虫觅食方向的影响。相比之下，个体内部的一致性，个体之间的相似度和归巢效率并未显示出少年的发展迹象。我们的研究结果支持早期探索后渠道化假说，但不支持早期循规蹈矩后自我定义假说。放宽自我进食效率的限制可能会有利于后海热带海鸟的高变异性。我们的简单方法可以通过比较广泛的中心觅食者的策略来进一步检验这些假设。