Animal-borne sensors for studying foraging and habitat use of marine predators in the Southern Ocean

有效的觅食对于海豹和海鸟等中心觅食者来说至关重要，它们通过在海上捕获的猎物在陆地上喂养幼崽/雏鸟。在南大洋，这些物种依赖于能量丰富的食物区，这些食物区也吸引了顶级捕食者，其中许多捕食者使用声音来交流和寻找猎物。声音环境，尤其是鲸鱼、海豹甚至企鹅在水下发出的声音，可能会提供丰富的线索，指导磷虾捕食者在躲避捕食者和竞争对手的同时寻找栖息地。然而，人们对海洋动物如何利用这种声音信息知之甚少，也不知道来自航运和工业活动的噪音是否会干扰以声音为基础的觅食。该项目将使用并进一步开发尖端的标签技术来量化单个动物在几周内产生的声音和所经历的声景，以及它们的精细行为。微型标签记录了动物在几周内发出和听到的声音，以及它们的位置（GPS）和精细的身体运动（加速度计）。一个高频声纳也将被纳入评估猎物斑块密度。研究人员将在海豹和企鹅的多次觅食旅途中使用标签，以研究声音环境和生物环境如何影响搜索行为、觅食成功以及后代的生长。该博士项目将要求学生参与研究的各个方面，包括传感器设计和校准，实验设计和现场部署，以及数据分析和解释。鉴于所收集的大型复杂数据集，学生将开发计算效率高的分析工具以及集成多个传感器流的新推理方法。将开发方法来描述声场、发声率、运动努力，并量化猎物遭遇率和觅食时间。通过这种独特的数据组合，学生将研究动物如何定位和利用短暂的猎物斑块，并将这些资源转移给陆地上的后代，将其与遇到的音景描述和幼崽/小鸡生长的观察联系起来。将首先对圈养动物进行方法评估，并在现场通过与使用较小标签进行无线电跟踪的对照组进行比较来监测潜在的标签效果。在资金到位的情况下，标签将被部署在南乔治亚岛或其他亚南极岛屿上繁殖的动物身上。

Efficient foraging is critical for central place foragers such as seals and seabirds that provision pups/chicks on land via prey caught at sea. In the Southern Ocean, these species rely on energy rich food patches that also attract top-level predators, many of which use sound to communicate and find prey. The acoustic environment, and in particular underwater vocalizations from whales, seals and perhaps even penguins, may provide abundant cues to guide krill eaters in searching for patches while avoiding their predators and competitors. However, little is known about how marine animals harness this sonic information nor is it known whether noise from shipping and industrial activities may disrupt sound-based foraging. This project will use and further develop cutting-edge tag technology to quantify the sounds produced, and the soundscapes experienced, by individual animals along with their fine-scale behaviour over periods of weeks. The miniature tags record the sounds made and heard by animals along with their position (GPS) and fine-scale body movements (accelerometers) over periods of weeks. A high frequency sonar will also be incorporated to assess prey patch density. Tags will be deployed on seals and penguins over multiple foraging trips to study how soundscapes and biotic environment influence searching behaviour, foraging success and therefore offspring growth. This PhD project will require the student to be involved in all aspects of the research including sensor design and calibration, experiment design and field deployments, and data analysis and interpretation. Given the large complex datasets collected, the student will develop computationally efficient analysis tools along with new inferential methods integrating multiple sensor streams. Methods will be developed to describe sound fields, vocalization rates, locomotion effort, and to quantify prey encounter rates and time spent foraging. With this unique combination of data, the student will study how animals locate and exploit ephemeral prey patches and transfer these resources to offspring on land, relating this to descriptors of the soundscapes encountered and observations of pup/chick growth. Methods will be evaluated first on captive animals and potential tag effects will be monitored in the field by comparison with control groups of animals radio-tracked with smaller tags. Subject to funding, tags will be deployed on animals breeding on South Georgia or other sub-Antarctic islands.