Killer whale predation of harbour seals in the coastal waters of Scotland: investigating the ecological drivers and consequences of an apex predator-p

觅食动物决定在哪里，何时吃什么，吃什么，其结果对确定它们的健康至关重要。被其他动物捕食的动物也必须平衡觅食的好处和安全。诸如逃到避难所之类的反应可能会花费猎物的时间和精力，但可以确保它们的生存1，2。反过来，捕食者必须对猎物行为做出战略性反应，以最大限度地提高其觅食成功率。捕食者-猎物的相互作用提供了一个机制的基础，预测食物网结构和了解的动态和生态群落的弹性3港（Phoca vitulina）和灰色（Halichoerus grypus）海豹是密切相关的物种在英国的重叠分布。在苏格兰的一些地区经常可以看到虎鲸（Orcinus orca）捕食这两个物种;然而，捕食的规模在很大程度上是未知的4，5。与太平洋虎鲸（“生态类型”）的亚种群相反，大西洋的虎鲸可能以哺乳动物和鱼类猎物为食6 - 8。它们对猎物的选择很可能受到猎物可获得性（分布和丰度）和特征（例如，年龄、体型）。例如，在苏格兰，灰海豹体型较大，数量比斑海豹多，但它们往往在更远的海域觅食9。量化捕食事件的空间和时间模式，了解海豹捕食的行为和生物能量动力学是了解虎鲸觅食及其对苏格兰海豹种群的潜在影响的关键。这个博士项目将调查虎鲸捕食港口海豹的最终目标是为保护顶级捕食者种群和哺乳动物猎物提供信息。该项目将采用生物能量学方法，通过整合现有数据集并建立模型，以及在设得兰群岛收集新的实地数据，就地研究捕食者-被捕食者之间的相互作用。博士的主要目标是1）提供特定年龄阶段（如成年/幼仔）的估计灰鲸和港海豹消耗虎鲸在苏格兰沿海沃茨，2）量化海豹捕食的空间和时间变化，和3）调查捕食率是否可能导致观察到的港海豹种群数量下降。参考文献1.布朗，J.S.，Laundré，J. W. & Gurung，M.恐惧的生态学：最优觅食，博弈论和营养相互作用。J.哺乳动物。80，385 - 399（1999）。布朗，J. S. & Kotler，B.危险关税和捕食的觅食成本。Ecol. Lett. 7，999 - 1014（2004）。Portalier，S. M. J.，Fussmann，G. F.、Loreau，M. & Cherif，M.捕食者-猎物相互作用的力学：物理学的第一原理预测捕食者-猎物的大小比。功能33，323 - 334（2019）。Bolt，H. E、V，H。P.，劳拉，M. & Foote，A.在苏格兰近海沃茨虎鲸的发生：相对于减少的海豹种群分布的时间和空间模式。水保存三月新鲜。生态系统19，671 - 675（2009）。Deecke，V. B.，Nykänen，M.，Foote，A. D. & Janik，V. M.英国设得兰群岛附近虎鲸的发声行为和摄食生态。水13，79 - 88（2011）。Foote，A. D、Kuningas，S. & Samarra，F. I. P.北大西洋虎鲸研究：过去、现在和未来。J.Mar.Biol.Assoc.United Kingdom 94，1245 - 1252（2014）。Samarra，F. I. P. et al. Prey of killer whales（Orcinus orca）in Iceland. PLoS One 13，e0207287（2018）.8. Escherdain，E. North Atlantic killer whale Orcinus orca populations：a review of current knowledge and threats to conservation.妈妈Rev. 49，1 - 17（2019）.9.汤普森，P.M.，麦康奈尔，B。J.，Tollit，D. J.，Mackay，A. & Racey，P. A.马里湾斑海豹和灰海豹的分布、活动和食性比较。J.Appl.Ecol.33，1572 - 1584（1996）中所述。

Foraging animals make decisions about where, when, and what to eat, the outcome of which can be critical to determine their fitness. Animals that are prey to others must also balance foraging benefits and safety from predation. Responses such as fleeing to a refuge can cost prey time and energy but ensure their survival1,2. Predators, in turn, must respond strategically to prey behaviour to maximise their foraging success. Predator-prey interactions provide a mechanistic basis to predict food web structure and understand the dynamics and resilience of ecological communities3Harbour (Phoca vitulina) and grey (Halichoerus grypus) seals are closely related species with overlapping distributions in the UK. Killer whale (Orcinus orca) predation of both species is frequently observed in some parts of Scotland; however, the scale of predation is largely unknown4,5. In contrast to sub-populations of Pacific killer whales ('ecotypes'), killer whales in the Atlantic may feed on both mammal and fish prey6-8. Their prey selection is likely to be influenced by both prey availability (distribution and abundance) and traits (e.g., age class, body size). For example, grey seals are larger in size and are more abundant than harbour seals in Scotland but tend to forage further offshore9. Quantifying the spatial and temporal patterns of predation events and understanding the behavioural and bioenergetic dynamics of seal predation are key to understanding killer whale foraging and their potential impacts on seal populations in Scotland.This PhD project will investigate killer whale predation of harbour seals with the ultimate goal to inform the conservation of both the apex predator population and their mammal prey. The project will take a bioenergetics approach to study predator-prey interaction in situ by integrating and modelling existing datasets, and collecting new field data in Shetland. The key objectives of the PhD are to 1) provide age stage-specific (e.g. adult/pup) estimates of grey and harbour seal consumption by killer whales in coastal waters of Scotland, 2) quantify spatial and temporal variation in seal predation, and 3) investigate whether predation rates could lead to observed declines in harbour seal population numbers.References 1. Brown, J. S., Laundré, J. W. & Gurung, M. The Ecology of Fear: Optimal Foraging, Game Theory , and Trophic Interactions. J. Mammal. 80, 385-399 (1999).2. Brown, J. S. & Kotler, B. P. Hazardous duty pay and the foraging cost of predation. Ecol. Lett. 7, 999-1014 (2004).3. Portalier, S. M. J., Fussmann, G. F., Loreau, M. & Cherif, M. The mechanics of predator-prey interactions: First principles of physics predict predator-prey size ratios. Funct. Ecol. 33, 323-334 (2019).4. Bolt, H. E., V, H. P., Laura, M. & Foote, A. Occurrence of killer whales in Scottish inshore waters: temporal and spatial patterns relative to the distribution of declining harbour seal populations. Aquat. Conserv. Mar. Freshw. Ecosyst. 19, 671-675 (2009).5. Deecke, V. B., Nykänen, M., Foote, A. D. & Janik, V. M. Vocal behaviour and feeding ecology of killer whales orcinus orca around Shetland, UK. Aquat. Biol. 13, 79-88 (2011).6. Foote, A. D., Kuningas, S. & Samarra, F. I. P. North Atlantic killer whale research; past, present and future. J. Mar. Biol. Assoc. United Kingdom 94, 1245-1252 (2014).7. Samarra, F. I. P. et al. Prey of killer whales (Orcinus orca) in Iceland. PLoS One 13, e0207287 (2018).8. Jourdain, E. et al. North Atlantic killer whale Orcinus orca populations: a review of current knowledge and threats to conservation. Mamm. Rev. 49, 1-17 (2019).9. Thompson, P. M., Mcconnell, B. J., Tollit, D. J., Mackay, A. & Racey, P. A. Comparative Distribution, Movements and Diet of Harbour and Grey Seals from Moray Firth. J. Appl. Ecol. 33, 1572-1584 (1996).