Disease ecology and ecophysiology of wildlife in changing ecosystems

广泛的环境变化，包括生物多样性的丧失和栖息地的破碎化，以复杂的方式影响野生动物的健康。作为一个关键的例子，疾病传播可能因栖息地破碎化而增加或减少，这取决于野生动物宿主、寄生虫及其所处生态系统的特征。为了确定促进寄主-寄生虫平衡相互作用的管理干预措施，我们必须了解环境变化影响这些相互作用的机制。因此，本研究将探讨环境变化影响寄主-寄生虫相互作用的三种机制：1)通过捕食者种群丰度和组成的变化；2)通过影响寄生虫传播的生境变化；3)应激性免疫抑制。这项发现基金将资助一个由学生主导的研究项目，通过利用现有的大型数据集来检验这些假设。具体来说，我们将使用慢性消耗性疾病的长期数据集来检查捕食者——包括人类猎人和自然捕食者——在疾病传播和流行中的作用。我们还将与一个由野生动物管理人员和生物学家组成的团队开展战略合作，开展一项长期、大规模的研究，调查驼鹿和驯鹿的健康状况。这些关系和数据将使我们能够评估栖息地的变化（包括道路密度和破碎化）如何影响有蹄类动物的健康，特别是冬季蜱虫侵扰的严重程度和流行程度。此外，我们将研究这些与栖息地变化相关的变量是否也会影响驼鹿和驯鹿的生理应激，以及应激升高是否与免疫抑制有关。我们将以额外的实地抽样和实验室分析补充现有数据。所有分析都将利用从各种来源汇编的空间环境数据集。总的来说，拟议的项目将建设从本科生到博士生的学员的能力，他们将具备更好的技能和网络，以解决复杂的野生动物健康问题。我们的研究团队将对环境变化对寄主-寄生虫相互作用的影响产生新的见解，这将有助于预测和减轻未来环境变化对野生动物健康的影响。例如，我们的研究结果可能确定促进宿主-寄生虫平衡相互作用的新方法，包括旨在降低疾病患病率和减少寄生虫传播的景观配置的收获策略。我们的研究特别相关，因为它关注的是具有高度文化、经济和保护重要性的物种，包括驼鹿和驯鹿，以及在加拿大广泛关注的疾病，包括慢性消耗性疾病和冬季蜱虫。最后，通过与野生动物管理者的合作，我们的发现很有可能被纳入管理策略。

Widespread environmental change, including the loss of biodiversity and habitat fragmentation, affects wildlife health in complex ways. As a key example, disease transmission may increase or decrease in response to habitat fragmentation, depending on characteristics of wildlife hosts, parasites, and the ecosystems in which they live. To identify management interventions that promote balanced parasite-host interactions, we must understand the mechanisms by which environmental change affects those interactions. Accordingly, the proposed research will investigate three mechanisms by which environmental change is hypothesized to influence parasite-host interactions: 1) via changes in the abundance and composition of predator populations; 2) through habitat change that influences parasite transmission; and 3) through stress-induced immunosuppression. This Discovery Grant will fund a student-led research program to test these hypotheses by drawing on large, existing datasets. Specifically, we will use a long-term dataset of chronic wasting disease to examine the role of predators-including both human hunters and natural predators-in disease spread and prevalence. We will also develop strategic collaborations with a team of wildlife managers and biologists working on a long-term, large-scale study investigating moose and caribou health. These relationships and data will enable us to evaluate how habitat change, including road density and fragmentation, affects ungulate health, specifically winter tick infestation severity and prevalence. Moreover, we will examine whether these variables related to habitat change also influence physiological stress in moose and caribou, and whether elevated stress is linked with immunosuppression. We will supplement existing data with additional field sampling and lab analyses. All analyses will draw on spatial environmental datasets compiled from a variety of sources. Collectively, the proposed projects will build capacity of trainees ranging from undergraduate to PhD students, who will emerge with improved skills and networks to address complex wildlife health problems. Our research team will generate new insight into the effects of environmental change on parasite-host interactions, which will help predict and mitigate the effects of future environmental change on wildlife health. For example, our findings may identify novel approaches that promote balanced host-parasite interactions, including harvest strategies aimed at reducing disease prevalence and landscape configurations that minimize parasite transmission. Our research is particularly relevant as it focuses on species of high cultural, economic, and conservation importance, including moose and caribou, as well as diseases of widespread concern in Canada, including chronic wasting disease and winter tick. Finally, our findings have a high probability of being incorporated into management strategies through collaboration with wildlife managers.