1 School of Biological, Earth and Environmental Sciences, University College Cork , Cork , Ireland.
2 MaREI Centre, Environmental Research Institute, University College Cork , Cork , Ireland.
Biol Lett. 2019 Jul 26;15(7):20190208. doi: 10.1098/rsbl.2019.0208. Epub 2019 Jul 10.
Understanding how animals forage is a central objective in ecology. Theory suggests that where food is uniformly distributed, Brownian movement ensures the maximum prey encounter rate, but when prey is patchy, the optimal strategy resembles a Lévy walk where area-restricted search (ARS) is interspersed with commuting between prey patches. Such movement appears ubiquitous in high trophic-level marine predators. Here, we report foraging and diving behaviour in a seabird with a high cost of flight, the Atlantic puffin ( Fratercula arctica), and report a clear lack of Brownian or Levy flight and associated ARS. Instead, puffins foraged using tides to transport them through their feeding grounds. Energetic models suggest the cost of foraging trips using the drift strategy is 28-46% less than flying between patches. We suggest such alternative movement strategies are habitat-specific, but likely to be far more widespread than currently thought.
理解动物如何觅食是生态学的一个核心目标。理论表明,在食物均匀分布的情况下,布朗运动确保了最大的猎物遭遇率,但当猎物呈斑块状分布时,最佳策略类似于莱维漫步,其中区域限制搜索(ARS)与在猎物斑块之间的迁徙交替进行。这种运动似乎在高营养级的海洋捕食者中无处不在。在这里,我们报告了一种飞行成本很高的海鸟——大西洋海雀( Fratercula arctica)的觅食和潜水行为,并且明显缺乏布朗运动或莱维飞行以及相关的ARS。相反,海雀利用潮汐将它们运送到觅食地。能量模型表明,使用漂流策略进行觅食旅行的成本比在斑块之间飞行低 28-46%。我们认为这种替代的运动策略是特定于栖息地的,但可能比目前想象的更为普遍。