Wingfield John C, Hau Michaela, Boersma P Dee, Romero L Michael, Hillgarth Nigella, Ramenofsky Marilyn, Wrege Peter, Scheibling Robert, Kelley J Patrick, Walker Brian, Wikelski Martin
Department of Biology, Box 351800, University of Washington, Seattle, WA 98195, USA; Department of Neurobiology, Physiology and Behavior, University of California, One Shields Avenue, Davis, CA 95616, USA.
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA; Max-Planck-Institut für Ornithologie, Seewiesen, and Univerzsity of Konstanz, Konstanz, Germany.
Gen Comp Endocrinol. 2018 Apr 1;259:20-33. doi: 10.1016/j.ygcen.2017.10.015. Epub 2017 Oct 26.
El Niño Southern Oscillation events (ENSO) and the subsequent opposite weather patterns in the following months and years (La Niña) have major climatic impacts, especially on oceanic habitats, affecting breeding success of both land and sea birds. We assessed corticosterone concentrations from blood samples during standardized protocols of capture, handling and restraint to simulate acute stress from 12 species of Galapagos Island birds during the ENSO year of 1998 and a La Niña year of 1999. Plasma levels of corticosterone were measured in samples collected at capture (to represent non-stressed baseline) and subsequently up to 1 h post-capture to give maximum corticosterone following acute stress, and total amount of corticosterone that the individual was exposed to during the test period (integrated corticosterone). Seabird species that feed largely offshore conformed to the brood value hypothesis whereas inshore feeding species showed less significant changes. Land birds mostly revealed no differences in the adrenocortical responses to acute stress from year to year with the exception of two small species (<18 g) that had an increase in baseline and stress responses in the ENSO year - contrary to predictions. We suggest that a number of additional variables, including body size and breeding stage may have to be considered as explanations for why patterns in some species deviated from our predictions. Nevertheless, comparative studies like ours are important for improving our understanding of the hormonal and reproductive responses of vertebrates to large scale weather patterns and global climate change in general.
厄尔尼诺-南方涛动事件（ENSO）以及随后数月和数年出现的相反天气模式（拉尼娜）具有重大气候影响，尤其是对海洋栖息地，影响着陆地和海鸟的繁殖成功率。我们在1998年厄尔尼诺年和1999年拉尼娜年期间，对加拉帕戈斯群岛12种鸟类进行了标准化的捕捉、处理和约束实验，以模拟急性应激，评估了血液样本中的皮质酮浓度。在捕捉时（代表无应激基线）以及随后捕捉后长达1小时采集样本，测量皮质酮的血浆水平，以得出急性应激后皮质酮的最大值，以及个体在测试期间暴露于皮质酮的总量（综合皮质酮）。主要在近海觅食的海鸟物种符合育雏值假说，而在近岸觅食的物种变化不太显著。陆地鸟类除了两种小型物种（<18克）在厄尔尼诺年基线和应激反应有所增加外，大多数物种每年对急性应激的肾上腺皮质反应没有差异，这与预测相反。我们认为，可能需要考虑一些额外的变量，包括体型和繁殖阶段，以解释为什么某些物种的模式与我们的预测不同。尽管如此，像我们这样的比较研究对于提高我们对脊椎动物对大规模天气模式和全球气候变化的激素和生殖反应的理解非常重要。
