Ecology of fear: ecological and evolutionary consequences of non-consumptive effects of parasites

恐惧生态学：寄生虫非消耗性影响的生态和进化后果

• 批准号: RGPIN-2020-03910
• 负责人: Luong, Lien
• 金额: $ 2.4万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744785
• 关键词: Ecology; fear; ecological; evolutionary; consequences

Parasites can cause significant harm to their hosts, hence potential hosts should try to avoid coming into contact with infectious stages of the parasite. Hosts can avoid exposure to infection by avoiding infective stages, associated cues, infected individuals, or alter their habitat use to avoid encountering parasite. These indirect non-consumptive effects are known as the "ecology of fear". The proposed project will experimentally answer the following questions: 1) Are the non-consumptive effects (NCEs) of parasites context and state-dependent? When an organism is exposed to parasites, it may change it's activity, rate of respiration, feeding behaviour, space use, and/or time allocation to various activities in order to avoid infection. Exactly how individuals respond to a perceived threat will depend on the environmental conditions and it's own internal condition (age, sex, energetic state, etc.). We will investigate the context-dependent nature of the NCE and whether the effects carry over across developmental stages and reproductive states. 2) Are there trait-mediated indirect effects of parasites? Parasites can also modify the behaviour of the host in ways that influence how it interacts with non-host species in the community (e.g., competitors, predators). The perception of infection risk could cause an increase in activity, which could in turn put an individual at greater risk of detection by predators. We will investigate the potential for conflict between anti-parasite and anti-predator defenses. 3) Are the NCEs of parasites on host metabolism context and state-dependent? The "fight or flight" response to a natural enemy often involves increased activity and respiration. We will measure the metabolic rate of flies exposed to parasites (without contact) over the short- and long-term. The metabolic rate of an organism is known to vary with sex, age, reproductive status, and external conditions (e.g., temperature, crowding). In addition to examining the state-dependent nature of the metabolic changes, measuring the reaction norm of the mean CO2 production under different conditions, including duration of exposure, types of parasite cues, and density of conspecifics. We will also measure associated changes in fly feeding behaviour. 4) What are the evolutionary consequences of NCE? Even as evidence for the ecology of fear and its fitness consequences mounts, the long-term evolutionary consequences of non-consumptive effects remains poorly understood. We will employ "laboratory natural selection" in which the environment of a laboratory-maintained population is altered (i.e., exposed to parasites) and the survivors become the parents of the next generation. The treatment populations will be compared to unaltered control populations after 10 generations. While multiple responses are possible, we will focus on changes in metabolism, feeding behaviour, body mass, anti-parasite behaviors (grooming, activity), and resistance to infection.

寄生虫会对宿主造成重大伤害，因此潜在的寄主应试图避免与寄生虫的传染阶段接触。宿主可以避免通过感染阶段，相关提示，感染的个体或改变其栖息地以避免遇到寄生虫的栖息地来避免感染。这些间接的非消费效应被称为“恐惧的生态学”。拟议的项目将通过实验回答以下问题：1）寄生虫上下文和国家依赖性的非消费性效应（NCE）？当生物体暴露于寄生虫时，它可能会改变其活动，呼吸速度，进食行为，空间使用和/或时间分配给各种活动，以避免感染。个人如何应对感知的威胁将取决于环境条件及其自身的内部状况（年龄，性别，充满活力的状态等）。我们将研究NCE的上下文依赖性，以及影响是否跨发育阶段和生殖状态进行。 2）寄生虫是否存在性状介导的间接影响？寄生虫还可以以影响社区中非宿主物种相互作用的方式（例如竞争者，掠食者）来改变宿主的行为。感染风险的看法可能导致活动增加，这反过来又可能使人面临捕食者发现更大的风险。我们将调查抗寄生虫和抗侵犯防御之间发生冲突的潜力。 3）寄生虫在宿主代谢环境和状态依赖性上是否存在？对天然敌人的“战斗或飞行”反应通常涉及增加活动和呼吸。我们将在短期和长期内测量暴露于寄生虫的代谢率（无接触）。已知有机体的代谢率随性，年龄，生殖状态和外部条件（例如温度，拥挤）而变化。除了检查代谢变化的状态依赖性外，还测量了在不同条件下平均二氧化碳产生的反应规范，包括暴露持续时间，寄生虫线索的类型和同种特定的密度。我们还将衡量蝇喂食行为的相关变化。 4）NCE的进化后果是什么？即使作为恐惧及其适应性后果的生态的证据也加剧了，非消耗性效应的长期进化后果仍然很少了解。我们将采用“实验室自然选择”，其中改变了实验室维护人群的环境（即暴露于寄生虫），幸存者成为下一代的父母。 10代后，将将治疗群体与不变的对照群体进行比较。虽然可以做出多种反应，但我们将专注于代谢，喂养行为，体重，抗寄生虫行为（修饰，活动）和对感染的抵抗力的变化。