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

觅食动物会决定何时何地吃什么，这些决定的结果对它们的健康至关重要。被其他动物捕食的动物也必须在觅食利益和安全之间取得平衡。逃到避难所这样的反应会消耗猎物的时间和精力，但却能确保它们的生存。捕食者，反过来，必须有策略地对猎物的行为做出反应，以最大限度地提高它们的觅食成功率。捕食者-猎物相互作用为预测食物网结构和了解生态群落的动态和恢复力提供了机制基础。在英国，港海豹（Phoca vitulina）和灰海豹（Halichoerus grypus）是密切相关的物种，分布重叠。虎鲸（Orcinus orca）在苏格兰的一些地区经常观察到这两种物种的捕食；然而，捕食的规模在很大程度上是未知的。与太平洋虎鲸亚种群（“生态型”）不同，大西洋的虎鲸可能以哺乳动物和鱼类为食。它们的猎物选择很可能受到猎物可用性（分布和丰度）和特征（例如，年龄类别、体型）的影响。例如，灰海豹比苏格兰的斑海豹体型更大，数量也更多，但它们倾向于在离岸更远的地方觅食。量化捕食事件的时空模式，了解海豹捕食的行为和生物能量动态，是了解苏格兰虎鲸觅食及其对海豹种群潜在影响的关键。这个博士项目将调查虎鲸捕食海豹的行为，最终目的是为保护顶级捕食者种群和它们的哺乳动物猎物提供信息。该项目将采用生物能量学方法，通过整合和模拟现有数据集，并在设得兰群岛收集新的实地数据，来研究捕食者-猎物在原位的相互作用。博士学位的主要目标是1)提供苏格兰沿海水域虎鲸对灰海豹和港海豹消耗量的年龄阶段（例如成年/幼崽）估计，2)量化海豹捕食的时空变化，以及3)调查捕食率是否会导致观察到的港海豹数量下降。引用1。Brown， J. S, laundr<s:1>， J. W. & Gurung， M.恐惧生态学：最优觅食、博弈论和营养相互作用。[j] .动物学报，2004,32(5):387 - 398（1999）。[j]布朗，J. S. & Kotler， B. P.。生态。2 .科学通报，2004,(1)。Portalier, s.m.j, Fussmann, g.f, Loreau， M. & Cherif， M.捕食者-猎物相互作用的机制：物理学的第一原理预测捕食者-猎物的大小比。功能。3 .中国生物医学工程学报，2016,32(2):444 - 444。Bolt， H. E., V .， H. P., Laura， M. & Foote， A.。苏格兰近海虎鲸的发生：与下降的海豹种群分布相关的时间和空间模式。Aquat。Conserv。3月Freshw。生态学报，2009,39(5):671-675。Deecke， V. B., Nykänen， M., Foote， A. D.和Janik， V. M.，英国设得兰群岛虎鲸的发声行为和摄食生态学。Aquat。5 .生物学报，2013,39(4):558 - 558。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.生物学。Assoc。7.联合王国94,1245-1252（2014）。萨马拉，f.i.p.等。冰岛虎鲸（Orcinus orca）的猎物。《科学通报》，2013,32(5):481 - 481。j . j .等。北大西洋虎鲸种群：对当前知识和保护威胁的回顾。Mamm。Rev. 49,1 -17（2019）。汤普森，P. M，麦康奈尔，B. J，托利特，D. J，麦凯，A.和蕾西，P. A.马里湾港海豹和灰海豹的比较分布、运动和饮食。j:。生态学报，33（1996）。

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).