The dynamics of the subtropical pelagic ecosystems of the Northeast Atlantic are still poorly known due to the high costs associated with sampling large oceanic areas. Top predators can be used as alternative low-cost samplers and indicators of the temporal variability of such systems. To study the variation in the composition of pelagic species through time in the broad Canary current region, we analysed foraging trips and regurgitations of Cory's shearwaters Calonectris borealis nesting on Selvagens islands, in 2008–2011 and 2016–2018. Fisheries data, oceanographic variables and the North Atlantic Oscillation were explored as possible explanatory variables for trends in behaviour and diet. Cory's shearwaters' diet, complemented by fisheries data, revealed marked changes in the composition of the pelagic fish communities. In 2016 there was a peak in the abundance of the Atlantic chub mackerel Scomber colias, followed by an explosive increase in the abundance of the Longspine snipefish Macroramphosus scolopax in 2017 and 2018, as deduced from the diet composition of the Cory's shearwater, and supported by fisheries data, in the broad oceanic area surrounding the Selvagens islands. Oceanographic variables did not show fluctuations correlated with these marked shifts in pelagic fish availability, the causes of which remain largely unknown. This study highlights the importance of the Atlantic chub mackerel and of the Longspine snipefish in the Madeira/Canary region and exemplifies the efficiency of avian predators in revealing rapid changes in pelagic communities of oceanic domains. Such trends and variations need to be better monitored and understood to measure the impact of ongoing global changes and to sustainably manage the marine environment and resources.

东北大西洋亚热带中上层生态系统的动力学仍然鲜为人知，因为与采样大洋区相关的高昂费用。顶级掠食者可以用作此类系统的低成本低成本采样器和时间变异性指标。为了研究金丝雀广泛流域中上层鱼类的组成随时间的变化，我们分析了科里剪力水Calonectrisborealis的觅食旅行和反流在2008–2011年和2016–2018年在Selvagens岛上筑巢。探索了渔业数据，海洋学变量和北大西洋涛动，作为行为和饮食趋势的可能解释变量。科里的shear水饮食与渔业数据相辅相成，揭示了远洋鱼类群落组成的显着变化。2016年，大西洋the鲭鱼Scomber colias的丰度达到顶峰，随后，Longspine ipe鱼Macroramphosus scolopax的丰度急剧增加。在2017年和2018年，根据塞尔（Selvagens）群岛周围广阔的海洋区域，根据科里（Cory）的shear水的饮食组成推导得出并得到渔业数据的支持。海洋学变量没有显示出与中上层鱼类供应量的这些明显变化有关的波动，其成因很大程度上未知。这项研究强调了马德拉岛/加那利地区大西洋Atlantic鱼和长脊s鱼的重要性，并举例说明了鸟类掠食者揭示海洋域中上层群落快速变化的效率。需要更好地监测和了解这种趋势和变化，以衡量不断变化的全球变化的影响并可持续地管理海洋环境和资源。