Handley Jonathan M, Thiebault Andréa, Stanworth Andrew, Schutt David, Pistorius Pierre
DST/NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, Department of Zoology, Nelson Mandela University, South Campus, Port Elizabeth 6031, South Africa.
Falklands Conservation, PO Box 26, Stanley FIQQ 1ZZ, Falkland Islands.
R Soc Open Sci. 2018 Aug 22;5(8):171449. doi: 10.1098/rsos.171449. eCollection 2018 Aug.
Predator dietary studies often assume that diet is reflective of the diversity and relative abundance of their prey. This interpretation ignores species-specific behavioural adaptations in prey that could influence prey capture. Here, we develop and describe a scalable biologging protocol, using animal-borne camera loggers, to elucidate the factors influencing prey capture by a seabird, the gentoo penguin (). From the video evidence, we show, to our knowledge for the first time, that aggressive behavioural defence mechanisms by prey can deter prey capture by a seabird. Furthermore, we provide evidence demonstrating that these birds, which were observed hunting solitarily, target prey when they are most discernible. Specifically, birds targeted prey primarily while ascending and when prey were not tightly clustered. In conclusion, we show that prey behaviour can significantly influence trophic coupling in marine systems because despite prey being present, it is not always targeted. Thus, these predator-prey relationships should be accounted for in studies using marine top predators as samplers of mid- to lower trophic-level species.
捕食者饮食研究通常假定饮食反映了其猎物的多样性和相对丰度。这种解释忽略了猎物特定物种的行为适应性，而这些适应性可能会影响猎物的捕获。在这里，我们开发并描述了一种可扩展的生物记录协议，使用动物携带的相机记录仪，以阐明影响海鸟巴布亚企鹅猎物捕获的因素。根据视频证据，据我们所知，我们首次表明猎物的攻击性防御行为机制可以阻止海鸟捕获猎物。此外，我们提供的证据表明，这些单独捕猎的鸟类在猎物最容易辨认时进行捕猎。具体来说，鸟类主要在上升时以及猎物没有紧密聚集时捕食猎物。总之，我们表明猎物行为可以显著影响海洋系统中的营养耦合，因为尽管有猎物存在，但它们并不总是被瞄准。因此，在以海洋顶级捕食者作为中低营养级物种采样器的研究中，应考虑这些捕食者与猎物的关系。
