在夏末和秋天,强烈的热带气旋的通过会极大地扰乱海洋和沿海生态系统。对个人和海洋社区的直接负面影响可能是巨大的,尤其是在沿海地区,1,2,3,4但旋风也可以增强中上层的初级和次级生产。5,6,7,8,9然而,旋风对公海海洋生物的影响仍然知之甚少。这里,我们研究了它们对广泛的高级捕食者觅食运动的影响,海燕(Pterodromadeserta),在中纬度北大西洋飓风季节。与先前在热带和中纬度地区研究的中上层海鸟相反,10,11Desertas海燕没有通过改变航向来避免旋风,他们也没有在旋风眼中寻求更平静的条件。大约有三分之一的海燕从它们的繁殖群体中追踪到,它们与接近的旋风相互作用。遇到强风,鸟类降低了地面速度,可能是在飞行中花费更少的时间。四分之一的鸟类跟随飓风醒来数天,超过数千公里,第一次记录在这里的行为。在这些唤醒中,顺风支撑高于替代路线。此外,在中尺度(小时周和数百公里),海面温度下降,地表叶绿素急剧增加,表明对海洋分层的直接影响,初级生产,因此,大概是猎物的丰度和表面摄食海燕的可及性。因此,我们假设旋风尾流提供了可预测的有利风况和觅食机会。因此,气旋可能对许多中纬度中上层海鸟的人口统计产生积极的净影响,很可能,其他海洋顶级捕食者。
In late summer and autumn, the passage of intense tropical cyclones can profoundly perturb oceanic and coastal ecosystems. Direct negative effects on individuals and marine communities can be dramatic, especially in the coastal zone,1,2,3,4 but cyclones can also enhance pelagic primary and secondary production.5,6,7,8,9 However,
cyclone impacts on open ocean marine life remain poorly understood. Here, we investigate their effects on the foraging movements of a wide-ranging higher predator, the Desertas petrel (Pterodroma deserta), in the mid-latitude North Atlantic during hurricane season. Contrary to previously studied pelagic seabirds in tropical and mid-latitude regions,10,11 Desertas petrels did not avoid cyclones by altering course, nor did they seek calmer conditions within the
cyclone eye. Approximately one-third of petrels tracked from their breeding colony interacted with approaching cyclones. Upon encountering strong winds, the birds reduced ground speed, likely by spending less time in flight. A quarter of birds followed
cyclone wakes for days and over thousands of kilometers, a behavior documented here for the first time. Within these wakes, tailwind support was higher than along alternative routes. Furthermore, at the mesoscale (hours-weeks and hundreds of kilometers), sea surface temperature dropped and surface chlorophyll sharply increased, suggesting direct effects on ocean stratification, primary production, and therefore presumably prey abundance and accessibility for surface-feeding petrels. We therefore hypothesize that
cyclone wakes provide both predictably favorable wind conditions and foraging opportunities. As such, cyclones may have positive net effects on the demography of many mid-latitude pelagic seabirds and, likely, other marine top-predators.