Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, AP 70275, México DF, 04510, México.
CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 Route de Mende, 34293, Montpellier, France.
Ecology. 2018 May;99(5):1063-1072. doi: 10.1002/ecy.2179.
Understanding and modeling population change is urgently needed to predict effects of climate change on biodiversity. High trophic-level organisms are influenced by fluctuations of prey quality and abundance, which themselves may depend on climate oscillations. Modeling effects of such fluctuations is challenging because prey populations may vary with multiple climate oscillations occurring at different time scales. The analysis of a 28-yr time series of capture-recapture data of a tropical seabird, the Nazca Booby (Sula granti), in the Galápagos, Ecuador, allowed us to test for demographic effects of two major ocean oscillations occurring at distinct time-scales: the inter-annual El Niño Southern Oscillation (ENSO) and inter-decadal oscillations. As expected for a tropical seabird, survival of fledgling birds was highly affected by extreme ENSO events; by contrast, neither recruitment nor breeding participation were affected by either ENSO or decadal oscillations. More interesting, adult survival, a demographic trait that canalizes response to environmental variations, was unaffected by inter-annual ENSO oscillations yet was shaped by the Pacific Decadal Oscillation and small pelagic fish regime. Adult survival decreased during oceanic conditions associated with higher breeding success, an association probably mediated in this species by costs of reproduction that reduce survival when breeding attempts end later. To our knowledge, this is the first study suggesting that survival of a vertebrate can be vulnerable to a natural multidecadal oscillation.
了解和建模人口变化对于预测气候变化对生物多样性的影响至关重要。高营养级生物受到猎物质量和数量波动的影响，而这些波动本身可能取决于气候波动。模拟这种波动的影响具有挑战性，因为猎物种群可能因发生在不同时间尺度上的多种气候波动而发生变化。对厄瓜多尔加拉帕戈斯群岛的热带海鸟 Nazca 海鸟（Sula granti） 28 年的捕获-再捕获数据时间序列的分析，使我们能够测试两种主要海洋波动的人口统计学效应，这两种波动发生在不同的时间尺度上：年度厄尔尼诺南方涛动（ENSO）和十年间的波动。正如对热带海鸟的预期那样，雏鸟的存活率受到极端 ENSO 事件的高度影响；相比之下，无论是 ENSO 还是十年间的波动，都不会影响招募或繁殖参与度。更有趣的是，成年个体的存活率（一种将环境变化的响应进行渠道化的人口特征）不受年度 ENSO 波动的影响，但受太平洋年代际振荡和小磷虾鱼群的影响。在与繁殖成功率较高相关的海洋条件下，成年个体的存活率下降，这种关联在该物种中可能是由繁殖成本介导的，当繁殖尝试结束较晚时，繁殖成本会降低存活率。据我们所知，这是第一个表明脊椎动物的存活率可能容易受到自然的多年代际波动影响的研究。
