When sea‐ice clock is ahead of Adélie penguins’ clock
When sea‐ice clock is ahead of Adélie penguins’ clock
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当海冰时钟领先于阿德利企鹅的时钟时
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Ancel
中科院分区：
文献类型：
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作者：
M. Beaulieu;A. Dervaux;A. Thierry;David Lazin;Y. Maho;Y. Ropert‐Coudert;M. Spée;T. Raclot;A. Ancel
1. 在极地地区，海冰的范围和动态正在发生变化。这影响了海洋生产力，进而影响浮游生物群落和企鹅等极地顶级捕食者。然而，对潜在的行为和生理机制仍然知之甚少。
2. 在这里，我们监测的生态生理反应阿德利企鹅（Pygoscelis adeliae）对在两个季节的海冰退缩的时间对比。除了经典的繁殖参数，如觅食旅行时间，体重和繁殖成功率，我们还研究了食物相关的压力（通过血浆皮质酮浓度），营养状态（通过代谢水平）和企鹅栖息地的使用（通过血液同位素值）。
3. 身体质量和繁殖成功率保持不变，但觅食行程较短时，海冰消退较早。恒定的血浆皮质酮浓度表明，没有喂养条件导致食物相关的压力。然而，代谢物水平较低时，海冰退缩早，这表明觅食性能和食物的质量/数量不同。事实上，同位素比率表明，当海冰过早消退时，像鱼这样的沿海猎物对企鹅的饮食贡献更大。
4. 早期海冰的退缩与较高的叶绿素浓度有关，这有利于磷虾的补充。奇怪的是，这与企鹅饮食中较高的磷虾贡献无关。我们认为，浮游植物的质量（而不是数量）的变化，影响磷虾招聘，迫使企鹅切换到更可用的猎物，如沿海鱼类。
5. 在南极的一些地区，海冰正在越来越早地消退。在本研究中，尽管海冰退缩的时间和连续的海洋生产力在两年之间有很大差异，但阿德利企鹅并没有受到严重影响，因为它们能够调整自己的海上行为，从而保持身体状况和繁殖成功率不变。
6. 这表明，海冰退缩的时间并不代表一个重要的威胁，阿德利企鹅的人口，至少只要替代资源仍然可用和其他环境参数，如冬季海冰范围没有显着改变。
1. In Polar Regions, the extent and dynamics of sea-ice are changing. This affects the ocean productivity which consecutively impacts plankton communities and polar top predators like penguins. Yet, the underlying behavioural and physiological mechanisms remain poorly understood.
2. Here we monitored the ecophysiological responses of Adelie penguin (Pygoscelis adeliae) pairs during two seasons of contrasting timing of sea-ice retreat. Beside classical breeding parameters like foraging trip duration, body mass and reproductive success, we also investigated food-related stress (via plasma corticosterone concentration), nutritional state (via metabolite levels) and the use of penguins’ habitat (via blood isotopic values).
3. Body mass and reproductive success remained unchanged but foraging trips were shorter when sea-ice retreated earlier. Constant plasma corticosterone concentrations indicated that none of the feeding conditions resulted in a food-related stress. However metabolite levels were lower when sea-ice retreated early, suggesting that the foraging performance and the quality/quantity of food differed. Indeed isotopic ratios indicated that coastal prey like fish contributed more to the penguins’ diet when sea-ice retreated prematurely.
4. The early sea-ice retreat was related to higher chlorophyll concentrations, known to favour krill recruitment. Paradoxically, this was not associated to a higher krill contribution in the penguins’ diet. We propose that a shift in the phytoplankton quality (rather than quantity), affecting krill recruitment, forced penguins to switch to more available prey like coastal fish.
5. In some Antarctic regions, sea-ice is retreating earlier and earlier. In the present study, even though the timing of sea-ice retreat and the consecutive ocean productivity differed drastically between the 2 years, Adelie penguins were not severely affected because they were able to adjust their at-sea behaviour and thus maintained their body condition and reproductive success unchanged.
6. This suggests that the timing of sea-ice retreat does not represent an important threat to populations of Adelie penguins at least as long as alternative resources are still available and other environmental parameters like winter sea-ice extent are not dramatically altered.