ABSTRACT

In a study of the foraging behaviour of the giant Pacific octopus Enteroctopus dofleini, we designed two types of experimental food patches to measure habitat preferences and perceptions of predation risk. The first patch successfully measured giving-up densities (GUDs), confirmed by octopus prey presence and higher foraging at sites with historically greater octopus presence. However, nontarget foragers also foraged on these experimental food patches. Our second floating patch design successfully excluded nontarget species from subtidal patches, and from intertidal patches at high tide, but allowed for foraging by E. dofleini. The second design successfully measured GUDs and suggested that octopus preferred foraging in a subtidal habitat compared to an intertidal habitat. We ascribe the higher GUD in the intertidal habitat to its higher predation risk relative to the subtidal habitat. The second patch design seems well suited for E. dofleini and, in conjunction with a camera system, could be used to provide behavioural indicators of the octopus's abundance, perceptions of habitat quality and predation risk.

中文翻译：

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设计用于测量章鱼觅食强度的实验性食品补丁：以巨型章鱼Enteroctopus dofleini为例

摘要

在对巨型太平洋章鱼Enteroctopus dofleini的觅食行为的研究中，我们设计了两种类型的实验性食物斑块，以测量栖息地的偏好和对捕食风险的感知。第一个斑块成功地测量了放弃密度（GUD），这一点已被章鱼的猎物和在历史上章鱼数量较多的地点觅食的现象所证实。但是，非目标觅食者也在这些实验性食物上觅食。我们的第二个浮动补丁设计成功地将非目标物种从潮下补丁和潮间带中排除，但允许E. dofleini进行觅食。第二个设计成功地测量了GUD，并建议章鱼比潮间栖息地更喜欢在潮下栖息地觅食。我们将潮间带生境中较高的GUD归因于其相对于潮间带生境而言较高的捕食风险。第二个补丁设计似乎非常适合大肠杆菌（E. dofleini），并且可以与摄像头系统结合使用，以提供章鱼丰度，栖息地质量感知和捕食风险的行为指标。