New perspectives on the consumptive and non-consumptive effects of predators

由于生态理论、实验室和实地研究以及技术/分析工具的最新进展，我们现在正处于捕食者-猎物生态学重大突破的风口浪尖。我们准备解释捕食率的复杂决定因素，以及这些因素如何受到捕食者觅食行为和捕食者-捕食者相互作用等因素的影响，并解决非消费性捕食者效应的作用（即，感知捕食风险（PPR）对猎物生理、行为和种群动态的影响。在这个资助周期中，我的团队将联合收割机结合观察研究，实地和实验室实验，以及建模练习，以全面解决主要的知识差距，并为理解捕食者-猎物相互作用建立新的基础。我们将在加拿大使用基于卫星的遥测和加速度计猞猁，郊狼，和他们的主要猎物（雪鞋兔）测试：1）捕食率是否受到比例依赖性，这是如何不同的捕食者和猎物物种：2）如果捕食运动符合流行的觅食理论，这是如何变化的周期性波动野兔丰度; 3）捕食者的猎物转换是否对应于对猎物物种比例变化的主动选择与被动反应;以及4）野兔对捕食风险的实验和自然变化的生理行为反应。将通过野兔种群低水平监测PPR增加对幼兔的母体影响，以确定成年和/或新招募的野兔是否有助于种群恢复。这些研究工作将得到使用模型捕食者-猎物系统（即，幼虫蝌蚪），在那里我们将操纵捕食者-猎物的相互作用，并解决长期存在的问题，在这个系统中具有高度可处理性的捕食者的消费效应。重要的是，蜻蜓蝌蚪系统也将用于评估PPR反应，这是如此普遍的实验室研究中使用该系统，是可复制的领域。 第二个捕食者-被捕食者模型系统（原生动物-食饵）将解决长期存在的谜团，即捕食者的非消耗性影响是否会单独影响捕食者-被捕食者的种群动态。这些调查将告知在这个系统中的捕食者的消费和非消费的影响，这将被扩展到一个相关的模型的捕食（和PPR）对雪鞋野兔种群周期的影响的人口模型的发展和参数化。总的来说，这些努力将合并理论和数据，以解释迄今尚未解决的捕食者-猎物相互作用的基本机制。这将为我们对捕食作为生态系统中主导力量的理解取得重大突破奠定基础。这项工作还将训练HQP进行强有力的科学调查和应用新方法来解决以前棘手的生态问题。

Owing to recent advances in ecological theory, lab and field studies, and technological/analytical tools, we are now at the cusp of major breakthroughs in predator-prey ecology. We are poised to explain the complex determinants of predation rate and how these are driven by factors like predator foraging behaviour and predator-predator interactions, as well as address the role of non-consumptive predator effects (i.e., perceived predation risk, PPR) on prey physiology, behaviour, and population dynamics. During this grant cycle my team will combine observational studies, field and lab experiments, and modelling exercises, to comprehensively address major knowledge gaps and establish a new basis for understanding predator-prey interactions. We will use satellite-based telemetry and accelerometry in Canada lynx, coyotes, and their primary prey (snowshoe hare) to test: 1) Whether predation rates are subject to ratio dependence and how this differs across predator and prey species; 2) If predator movements conform to prevailing foraging theory and how this varies with cyclic fluctuation in hare abundance; 3) If prey switching by predators corresponds to active choice vs. passive response to a change in prey species ratio; and 4) Physio-behavioural responses of hares to experimental and natural changes in predation risk. Maternal effects of increased PPR on juvenile hares will be monitored through a hare population low to determine whether adults and/or new recruits contribute to population recovery. These research efforts will be bolstered by experiments using a model predator-prey system (i.e., dragonfly larvae-tadpole), where we will manipulate predator-prey interactions and address longstanding questions related to consumptive effects of predators that have high tractability in this system. Importantly, the dragonfly-tadpole system also will serve to assess whether PPR responses, which are so prevalent in lab studies using this system, are replicable in the field. A second predator-prey model system (protist-alga), will address the longstanding enigma of whether non-consumptive effects of predators alone can affect predator-prey population dynamics. These investigations will inform the development and parameterization of a population model of the consumptive and non-consumptive effects of predators in this system, which will be extended to a related model of the effects of predation (and PPR) on the snowshoe hare population cycle. Collectively, these efforts will merge theory and data to explain fundamental mechanisms governing predator-prey interactions that to date have gone unresolved. This will set the stage for major breakthroughs in our understanding of predation as a dominant force in ecosystems. This work also will train HQP in robust scientific investigation and the application of novel approaches to address previously intractable ecological questions.