Collaborative Research: Hunting Behavior and Energetics of Free-Ranging Weddell Seals

这个合作研究项目的重点是使韦德尔海豹能够在寒冷、黑暗、南极快速冰层环境中觅食的行为和能量适应。为了回答这个问题，将测试与自由放养的韦德尔海豹(Leptonychotes Wedellii)的一般觅食策略、觅食位置、搜索模式、猎物检测、运动性能、潜水成本和觅食效率有关的假设。此外，还将检查潜水时的运动性能和行为，以估计与狩猎相关的成本和从狩猎中获得的好处(猎物捕获的类型和频率)。这项研究将为海洋哺乳动物的觅食策略提供独特的见解，并将有助于生理学(潜水和能量学)和生态学(觅食理论和行为生态学)领域的研究。这项拟议的研究建立在麦克默多海峡对韦德尔海豹的研究基础上，使用动物携带的视频系统/数据记录器来记录海洋哺乳动物在深处的行为、生理和运动表现。这提供了对韦德尔海豹捕猎策略、捕食者-猎物相互作用的首次观察，以及对潜水新陈代谢的相应估计。研究中使用的隔离冰洞方案允许海豹选择潜水的深度和持续时间，但它们必须回到一个单一的地方呼吸，这限制了它们的移动范围。此外，它们无法从水中拖出或与其他海豹互动，可能会接触到比自然觅食时更低的猎物密度。新的焦点是完全自由活动的海豹的行为和能量学，对它的所有重要限制都已经消除。尽管目前的研究证明了韦德尔海豹觅食的重要新原则，并增加了对潜水行为和游泳表现的了解，但现在至关重要的是确定这些原则是否适用于不受约束的动物。这项研究将继续雇用一支拥有高技能技术支持的多学科科学家团队。这一结果将推进对韦德尔海豹觅食生态的了解，并为在公开海洋中更难研究的其他海洋哺乳动物物种的类似研究奠定基础。最后，通过将研究从孤立的冰洞扩展到完全自由活动的条件，这项研究将为威德尔海豹在南极海洋生态系统中作为顶端捕食者的作用提供新的见解。

The focus of this collaborative research project is on the behavioral and energetic adaptations enable Weddell seals to forage in the cold, dark, Antarctic fast-ice environment. To answer this question, hypotheses related to general foraging strategy, foraging location, searching mode, prey detection, locomotor performance, the cost of diving and foraging efficiency of free-ranging Weddell seals (Leptonychotes weddellii) will be tested. In addition, locomotor performance and behavior during diving to estimate the costs associated with hunting and the benefits gained from hunting (type and frequency of prey captures) will be examined. This study will provide unique insight into marine mammal foraging tactics and will contribute to fields of physiology (diving and energetics) and ecology (foraging theory and behavioral ecology). The proposed study builds on research on Weddell seals in McMurdo Sound using an animal-borne video system/data logger to record the behavior, physiology and locomotor performance of marine mammals at depth. This provided first observations of Weddell seal hunting strategies, predator-prey interactions and corresponding estimates of diving metabolism. The isolated-ice-hole protocol used in the study allows seals to choose the depth and duration of a dive, but they must return to a single place to breathe, which limits their range of movement. In addition, they are unable to haul out of the water or interact with other seals and may be exposed to lower prey densities than when foraging naturally. The new focus is the behavior and energetics of completely free-ranging seals, for which all significant constraints have been removed. Although the current study has demonstrated important new principles in Weddell seal foraging and has increased understanding of diving behavior and swimming performance, it is now essential to determine whether those principles apply to unconstrained animals. The study will continue to employ a multidisciplinary team of scientists with highly skilled technical support. The results will advance the understanding of the foraging ecology of Weddell seals and create a basis for similar research on other species of marine mammals that are more difficult to study in the open ocean. Finally, by extending the study from an isolated ice hole to completely free-ranging conditions, this research will provide new insight into the role of Weddell seals as apex predators in the Antarctic marine ecosystem.