A direct test of the impact of infection on animal migration: consequences for parasite and host populations

感染对动物迁徙影响的直接测试：对寄生虫和宿主种群的影响

• 批准号: NE/V001809/1
• 负责人: Sarah Burthe
• 金额: $ 17.52万
• 依托单位: UK CENTRE FOR ECOLOGY & HYDROLOGY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV001809%2F1
• 关键词: direct; test; impact; infection; animal

Wildlife populations experience a wide range of infections that can both impact on their own health and cross species boundaries to pose environmental risks to farm animal and human health. The impact of this infection will be inextricably linked to a species' movement ecology, as the way in which animal movements around their environment is a major factor in determining how infections are transmitted and persist. Predicting infection dynamics and mitigating their impacts therefore requires understanding how infection influences animal movements and, in turn, understanding the consequences of animal movement for infection dynamics. We will therefore address three key questions in this project: 1) Does infection status influence individual migration strategy? 2) Does infection affect the survival and breeding success of migrants and residents to different extents? 3) Do differences in migratory behaviour scale up to affect levels of infection in host populations.We will investigate these questions in a partially migratory population of seabirds that breed on the Isle of May National Nature Reserve in South East Scotland but migrate along the East Coats of the UK. Recent theoretical studies have modelled three disease related mechanisms that could directly affect selection for, or against, migration. These are 1) migratory escape, whereby migration allows individuals to escape from high-exposure habitats or infected individuals. 2) migratory recovery, whereby infected individuals migrate to a different area to gain resources that facilitate recovery 3) migratory culling, whereby infected individuals suffer higher mortality during migration.We will firstly test whether natural levels of parasitism are associated with individual migration strategy expressed in an individual's first year of life and whether measures of immunity differ in juveniles that subsequently become resident or migrant. We will then experimentally test whether parasitism has a causal role through experimental reduction of parasite burden.We will then test whether parasitism is associated with differences in breeding success and survival of migrants and residents. We will use multi-year demographic data to link individual migration strategy to levels of parasitism and components of fitness to test a) whether parasitism is associated with any potential selective advantage of migration and b) the demographic routes through which this may operate.Finally we will test whether changes in population levels of parasitism between years is due to decreases in individual parasite burden as individuals recover from infection or the loss of infected hosts from the population as they fail to survive. This is important from a management or conservation point of view as these alternative explanations would lead to very different conclusions about the robustness of the population to infection.This study will therefore provide first combined test of how parasitism drives migratory movements in a partially migratory species with measuring the consequences for population level changes in parasite abundance and whether these result from high levels of host mortality. These are key to assessing the impact of migration on parasite persistence in the environment and the impact of parasitism on different components of animal populations.

野生动物种群会经历各种各样的感染，这些感染既会影响它们自身的健康，也会跨越物种界限，对农场动物和人类健康构成环境风险。这种感染的影响将与物种的运动生态密不可分，因为动物在其环境中的运动方式是决定感染如何传播和持续存在的主要因素。因此，预测感染动态并减轻其影响需要了解感染如何影响动物运动，进而了解动物运动对感染动态的影响。因此，我们将在这个项目中解决三个关键问题：1)感染状况是否影响个体迁移策略？2)感染是否不同程度地影响候鸟和常住鸟的生存和繁殖成功率？3)迁徙行为的差异是否会扩大到影响宿主人群的感染水平？我们将在部分迁徙的海鸟种群中调查这些问题，这些海鸟在苏格兰东南部的五月岛国家自然保护区繁殖，但沿着英国东海岸迁徙。最近的理论研究模拟了三种与疾病相关的机制，这些机制可以直接影响选择是否支持迁移。1)迁徙逃逸，即迁徙允许个体逃离高暴露的栖息地或受感染的个体。2)迁移恢复，即受感染的个体迁移到不同的地区以获得促进恢复的资源3)迁移扑杀，即受感染的个体在迁移期间死亡率较高。我们将首先测试寄生的自然水平是否与个体在生命第一年表达的个体迁移策略有关，以及随后成为居民或移民的幼虫的免疫措施是否不同。然后，我们将通过实验减少寄生虫负担来检验寄生是否具有因果作用。然后，我们将测试寄生是否与移民和居民的繁殖成功率和生存差异有关。我们将使用多年的人口统计数据，将个体迁移策略与寄生水平和适合度的组成部分联系起来，以测试a)寄生是否与任何潜在的迁移选择优势有关，以及b)这种优势可能通过的人口统计途径。最后，我们将测试种群间寄生水平的变化是由于个体从感染中恢复时个体寄生虫负担的减少，还是由于感染宿主无法生存而从种群中消失。从管理或保护的角度来看，这一点很重要，因为这些不同的解释将导致关于种群对感染的稳健性的非常不同的结论。因此，这项研究将首次提供关于寄生如何驱动部分迁徙物种的迁徙运动的综合测试，并测量寄生虫丰度的种群水平变化的后果，以及这些变化是否由高水平的宿主死亡率引起。这些是评估迁徙对环境中寄生虫持久性的影响以及寄生对动物种群不同组成部分的影响的关键。