Testing optimal foraging theory in a penguin-krill system
Testing optimal foraging theory in a penguin-krill system
复制标题
DOI：
10.1098/rspb.2013.2376
复制
发表时间：
2014-03-22
影响因子：
4.7
通讯作者：
Takahashi, Akinori
中科院分区：
文献类型：
--
作者：
Watanabe, Yuuki Y.;Ito, Motohiro;Takahashi, Akinori
食物在自然界中是不均匀分布的，了解动物如何寻找和利用食物斑块是生态学中的一个基本挑战。经典的边际价值定理（MVT）制定了最佳的补丁停留时间响应补丁质量。MVT一般在受控动物实验中得到证明;然而，由于在野外记录觅食行为的技术困难，它在自然捕食者-猎物系统中，特别是在三维海洋环境中没有得到充分的研究。使用动物携带的加速度计和摄像机，我们收集了一个罕见的数据集，其中的海洋捕食者（企鹅）的行为被记录同时与捕获时间的移动的，斑块分布的猎物（磷虾）。我们提供定性支持的MVT显示，（一）磷虾捕获率减少，在每次潜水的时间，假设在MVT，和（二）潜水持续时间（或补丁停留时间，控制潜水深度）增加短期，潜水规模的磷虾捕获率，但减少长期，约规模的磷虾捕获率，从MVT预测。我们的研究结果表明，一个单一的环境因素（即补丁质量）可以有相反的影响，动物的行为取决于时间尺度，强调多尺度的方法在理解复杂的觅食策略的重要性。
Food is heterogeneously distributed in nature, and understanding how animals search for and exploit food patches is a fundamental challenge in ecology. The classic marginal value theorem (MVT) formulates optimal patch residence time in response to patch quality. The MVT was generally proved in controlled animal experiments; however, owing to the technical difficulties in recording foraging behaviour in the wild, it has been inadequately examined in natural predator-prey systems, especially those in the three-dimensional marine environment. Using animal-borne accelerometers and video cameras, we collected a rare dataset in which the behaviour of a marine predator (penguin) was recorded simultaneously with the capture timings of mobile, patchily distributed prey (krill). We provide qualitative support for the MVT by showing that (i) krill capture rate diminished with time in each dive, as assumed in the MVT, and (ii) dive duration (or patch residence time, controlled for dive depth) increased with short-term, dive-scale krill capture rate, but decreased with long-term, bout-scale krill capture rate, as predicted from the MVT. Our results demonstrate that a single environmental factor (i.e. patch quality) can have opposite effects on animal behaviour depending on the time scale, emphasizing the importance of multi-scale approaches in understanding complex foraging strategies.