The Ross Sea, Antarctica, supports large populations of Emperor Penguin (Aptenodytes forsteri) and Adélie Penguin (Pygoscelis adeliae), two key meso-predators that occupy high trophic levels. Despite these species are largely studied, little is known about their diet outside the breeding period. In the present study, we investigated the intra-annual diet of Adélie and Emperor Penguins belonging to five colonies in the Ross Sea through the stable isotope analysis of different tissues (feathers and shell membranes), synthetized in different seasons, and guano that indicates recent diet. Penguin samples and prey (krill and fish) were collected during the Antarctic spring–summer. δ¹³C and δ¹⁵N of tissues and guano indicate spatio-temporal variation in the penguin diet. The krill consumption by Adélie Penguins was lowest in winter except in the northernmost colony, where it was always very high. It peaked in spring and remained prevalent in summer. The greatest krill contribution to Emperor Penguin’s diet occurred in summer. The relative krill and fish consumption by both species changed in relation to the prey availability, which is influenced by seasonal sea ice dynamics, and according to the penguin life cycle phases. The results highlight a strong trophic plasticity in the Adélie Penguin, whose dietary variability has been already recognized, and in the Emperor Penguin, which had not previously reported. Our findings can help understand how these species might react to resource variation due to climate change or anthropogenic overexploitation. Furthermore, data provides useful basis for future comparisons in the Ross Sea MPA and for planning conservation actions.

南极洲罗斯海拥有大量帝企鹅 ( Aptenodytes forsteri ) 和阿德利企鹅 ( Pygoscelis adeliae )，这两种重要的中观食肉动物占据高营养水平。尽管对这些物种进行了大量研究，但对它们在繁殖期之外的饮食知之甚少。在本研究中，我们通过不同季节合成的不同组织（羽毛和壳膜）的稳定同位素分析，调查了属于罗斯海五个殖民地的阿德利企鹅和帝企鹅的年内饮食，鸟粪表明最近饮食。企鹅样本和猎物（磷虾和鱼）是在南极春夏期间收集的。δ ¹³ C 和δ ¹⁵N 的组织和鸟粪表明企鹅饮食的时空变化。Adélie Penguins 的磷虾消耗量在冬季最低，但在最北端的殖民地除外，那里的磷虾消耗量一直很高。它在春季达到顶峰，并在夏季继续流行。磷虾对帝企鹅饮食的最大贡献发生在夏季。两种物种的磷虾和鱼类的相对消耗量与猎物的可用性有关，受季节性海冰动态和企鹅生命周期阶段的影响。结果突出了阿德利企鹅和帝企鹅的强大营养可塑性，其饮食变异性已经被认识到，而帝企鹅此前从未报道过。我们的研究结果有助于了解这些物种可能如何对气候变化或人为过度开发引起的资源变化做出反应。此外，数据为罗斯海海洋保护区的未来比较和规划保护行动提供了有用的基础。