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 relati...

长寿命物种的早期生命阶段对种群存续至关重要，但目前人们对其了解甚少。亟需开展纵向研究，以验证幼崽是否如假说所言，觅食效率低于成体。我们针对克罗泽群岛（亚南极群岛）的17只1岁龄王企鹅（Aptenodytes patagonicus），通过可实时传输潜水活动数据的微型标签，监测其出海首月内的潜水行为变化。同时为5只非繁殖成体佩戴同款标签作为对照。觅食表现数据显示，幼崽可划分为两个群体：第一群体的潜水深度更浅、时长更短，这或预示着早期死亡；第二群体的潜水深度与时长逐步增加，并成功度过出海首月。该存活幼崽群体的恢复时长与成体一致，但通常潜水深度更浅、时长更短。由此可见……