Data from: Early diving behaviour in juvenile penguins: improvement or selection processes

The early life stage of long-lived species is critical to the viability of population, but is poorly understood. Longitudinal studies are needed to test whether juveniles are less efficient foragers than adults as has been hypothesized. We measured changes in the diving behaviour of 17 one-year-old king penguins Aptenodytes patagonicus at Crozet Islands (subantartic archipelago) during their first months at sea, using miniaturized tags that transmitted diving activity in real time. We also equipped five non-breeder adults with the same tags for comparison. The data on foraging performance revealed two groups of juveniles. The first group made shallower and shorter dives that may be indicative of early mortality while the second group progressively increased their diving depths and durations, and survived the first months at sea. This surviving group of juveniles required the same recovery durations as adults, but typically performed shallower and shorter dives. There is thereby a relationship between improved diving behaviour and survival in young penguins. This long period of improving diving performance in the juvenile life stage is potentially a critical period for the survival of deep avian divers and may have implications for their ability to adapt to environmental change.

长寿物种的早期生命阶段对种群存续至关重要，但目前对其认知仍较为匮乏。亟需开展纵向研究，以验证学界此前提出的幼体觅食效率低于成体这一假说。本研究借助可实时传输潜水活动数据的微型电子标签，监测了克罗泽群岛（亚南极群岛）海域17只1岁龄王企鹅（Aptenodytes patagonicus）在出海首数月的潜水行为变化；同时为5只未参与繁殖的成体佩戴同款标签以作为对照。觅食表现的监测数据显示，幼企鹅可划分为两个类群：第一类群的潜水深度更浅、单次时长更短，这或预示其早期死亡；第二类群的潜水深度与时长则逐步提升，并成功度过出海首数月。该存活类群的幼体与成体所需的恢复时长一致，但整体潜水行为仍更浅、单次时长更短。由此可见，幼企鹅的潜水行为优化与其存活率之间存在关联。幼体阶段漫长的潜水能力优化过程，对深潜鸟类的存活而言或是一个关键窗口期，或对其适应环境变化的能力产生潜在影响。