19-EEID US-UK Collab: Disentangling transport and trophic effects of animal movement on infectious disease

19-EEID 美英合作：解开动物运动对传染病的运输和营养影响

• 批准号: BB/V004484/1
• 负责人: Thomas Morrison
• 金额: $ 118.41万
• 依托单位: University of Glasgow
• 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=BB%2FV004484%2F1
• 关键词: 19; EEID; US; UK; Collab

Mobile organisms, such as many species of birds, insects and ungulates, have long fascinated scientists and the general public because of the vast distances over which these animals travel and the large impacts they have on the dynamics of ecosystems they encounter. The high local densities and long-distance movements of mobile organisms provide seemingly ideal conditions for the emergence and spread of disease-causing pathogens, yet the ways in which mobile hosts modify the infection dynamics of less-mobile (i.e. resident) hosts is poorly understood. In this proposal, we take advantage of the widespread occurrence of gastrointestinal nematodes in one of the most intact and largest terrestrial animal migration systems in the world - the Serengeti wildebeest - to advance understanding of the impact of animal movement on parasite dynamics. We hypothesize that mobile hosts can affect parasite dynamics in resident hosts in at least two important ways. First, mobile hosts can shed parasites in locations visited by other hosts, thereby creating areas of high parasite density. Second, mobile hosts can profoundly change the environment in which parasites mature, for example by shortening the height of vegetation both through trampling and foraging, which can directly and indirectly modify the risk of parasite transmission to resident hosts. Because of their large effects on vegetation, mobile herbivores may promote or reduce parasite exposure risk by either i) concentrating parasites on the remaining vegetation, or ii) removing parasites through consumption. Alternatively, mobile hosts may alter the behaviour of other herbivores indirectly through their effects on vegetation, by iii) promoting regrowth of vegetation and thus attracting herbivores, or iv) consuming all of the food and thus displacing them. We aim to determine which of these direct and indirect, positive/negative effects are most important, and their mechanistic underpinnings. We will do so by examining the impacts of highly mobile wildebeest on the parasite abundance in the environment and in four wildlife species: topi, hartebeest, African Cape buffalo, and Grant's gazelle. In wildlife species, we will examine these different mechanisms using a combination of tracking data (GPS collars, camera traps, spatial distribution models) and molecular analyses of parasite infection dynamics in animals. This work will be combined with experiments that manipulate two of the main vegetative mechanisms that alter parasite availability in the environment: density of feces and grazing intensity on grasses. We will use this information to develop a general model of infection dynamics in mobile and resident hosts that will allow insight into the conditions in which infections are most likely to increase or decrease. The same dynamics that occur in resident wildlife hosts are also likely to play out in resident livestock, however in many systems around the world there is a lack of understanding of whether wildlife and livestock even share the same parasites. Thus, a broader impact of our project is to examine the extent to which mobile wildlife change the infection intensity in resident livestock, whether the two groups share the same populations of parasites and whether mobile wildlife benefit livestock by acting as a refugia for parasites that are sensitive to anti-parasite drug treatment (i.e. a natural buffer to anthelmintic resistance). Given that gastrointestinal parasites have an environmental stage to their life cycle, ecology plays a central role in their infection and transmission dynamics, opening the door for a range of exciting future research questions in disease ecology, animal health and wildlife-livestock interactions, as well as training opportunities with local animal health students and authorities.

移动生物体，例如许多鸟类、昆虫和有蹄类动物，长期以来一直令科学家和公众着迷，因为这些动物的迁徙距离很远，并且对它们所遇到的生态系统的动态产生巨大影响。移动生物体的高局部密度和长距离移动为致病病原体的出现和传播提供了看似理想的条件，但移动宿主如何改变移动性较低（即常驻）宿主的感染动态的方式却知之甚少。 。在这项提案中，我们利用世界上最完整和最大的陆地动物迁徙系统之一——塞伦盖蒂角马中广泛存在的胃肠道线虫来加深对动物运动对寄生虫动态影响的了解。我们假设移动宿主至少可以通过两种重要方式影响常驻宿主中的寄生虫动态。首先，移动宿主可以在其他宿主访问过的位置释放寄生虫，从而形成高寄生虫密度的区域。其次，移动宿主可以深刻改变寄生虫成熟的环境，例如通过践踏和觅食缩短植被的高度，这可以直接或间接降低寄生虫传播给居住宿主的风险。由于它们对植被的影响很大，移动食草动物可能会通过以下任一方式促进或减少寄生虫暴露风险：i) 将寄生虫集中在剩余植被上，或 ii) 通过食用去除寄生虫。或者，移动宿主可以通过对植被的影响来间接改变其他食草动物的行为，通过iii）促进植被再生，从而吸引食草动物，或iv）消耗所有食物，从而取代它们。我们的目标是确定这些直接和间接、积极/消极影响中哪些是最重要的，以及它们的机制基础。我们将通过研究高度流动的角马对环境和四种野生动物物种（托皮、狷羚、非洲水牛和格兰特瞪羚）寄生虫丰度的影响来实现这一目标。在野生动物物种中，我们将结合跟踪数据（GPS 项圈、相机陷阱、空间分布模型）和动物体内寄生虫感染动态的分子分析来研究这些不同的机制。这项工作将与操纵改变环境中寄生虫可用性的两种主要植物机制的实验相结合：粪便密度和草上的放牧强度。我们将利用这些信息来开发移动和常驻宿主感染动态的通用模型，以便深入了解感染最有可能增加或减少的情况。常驻野生动物宿主中发生的相同动态也可能在常驻牲畜身上发生，然而，在世界各地的许多系统中，人们对野生动物和牲畜是否共享相同的寄生虫缺乏了解。因此，我们项目的更广泛影响是研究流动野生动物在多大程度上改变了居民牲畜的感染强度，这两个群体是否拥有相同的寄生虫种群，以及流动野生动物是否通过充当寄生虫的避难所而使牲畜受益。对抗寄生虫药物治疗敏感（即抗蠕虫药耐药性的天然缓冲剂）。鉴于胃肠道寄生虫的生命周期有一个环境阶段，生态学在其感染和传播动力学中发挥着核心作用，这为疾病生态学、动物健康和野生动物与牲畜相互作用等一系列令人兴奋的未来研究问题打开了大门。作为与当地动物卫生学生和当局的培训机会。

项目成果

Defining null expectations for animal site fidelity.

定义动物场所保真度的零期望。

• DOI: 10.1111/ele.14148
• 发表时间: 2023
• 期刊: Ecology letters
• 影响因子: 8.8
• 作者: Picardi S

Interplay of competition and facilitation in grazing succession by migrant Serengeti herbivores

塞伦盖蒂迁徙食草动物放牧演替过程中竞争与促进的相互作用

• DOI: 10.1126/science.adg0744
• 发表时间: 2024
• 期刊: Science
• 影响因子: 56.9
• 作者: Anderson T

Behavioral responses of terrestrial mammals to COVID-19 lockdowns

陆生哺乳动物对 COVID-19 封锁的行为反应

• DOI: 10.1126/science.abo6499
• 发表时间: 2023
• 期刊: Science
• 影响因子: 56.9
• 作者: Tucker, Marlee A.;Schipper, Aafke M.;Adams, Tempe S.;Attias, Nina;Avgar, Tal;Babic, Natarsha L.;Barker, Kristin J.;Bastille-Rousseau, Guillaume;Behr, Dominik M.;Belant, Jerrold L.
• 通讯作者: Belant, Jerrold L.

Direct and indirect effects of fire on parasites in an African savanna

火灾对非洲稀树草原寄生虫的直接和间接影响

• DOI: 10.1111/1365-2656.14013
• 发表时间: 2023
• 期刊: Journal of Animal Ecology
• 影响因子: 4.8
• 作者: Donaldson J

Increasing Anthropogenic Disturbance Restricts Wildebeest Movement Across East African Grazing Systems

• DOI: 10.3389/fevo.2022.846171
• 发表时间: 2022-03
• 作者: J. Stabach;L. Hughey;R. Crego;C. Fleming;J. Hopcraft;P. Leimgruber;T. Morrison;J. Ogutu;R. Reid;J. Worden;R. Boone