Integrative Assessment Tools for Monitoring Muskox Health and Vulnerability in a Changing Arctic

北极的气候变化正在影响土著人民的生计、健康和生活方式，以及他们赖以为生的动物的生存和传统文化。最近的变暖导致南方动物及其病原体的北方范围扩大，宿主-寄生虫相互作用改变，疾病出现。此外，人类在北极的足迹不断增加（矿产和天然气勘探/开发、新的航运路线、研究活动和旅游业的增加）正在不可逆转地改变生态系统，加剧气候介导的野生动物压力。自2008年以来，我的团队一直在调查加拿大北极群岛麝牛的新疾病和死亡事件。其中包括：（一）与丹毒丝菌相关的多起严重、广泛的死亡事件，丹毒丝菌是一种以前在麝牛中未报告的细菌，在北极也未报告;（二）北极群岛上两种线虫肺蠕虫的入侵和快速范围扩张;以及（三）班克斯岛上2013年新发的严重脓疮或“orf”样病变。与此同时，最近的调查和轶事证据表明，麝香猫的数量在这些地区的一些显着下降。总之，这些事件表明生态条件和压力源的变化，最终导致疾病和死亡，并对人口产生影响。 * 本研究的总体目标是开发和测试用于麝牛健康评估的综合措施，这些措施可以通过以社区为基础的监测来实施，并用于了解和监测麝牛对环境变化的敏感性。 * 以前，我开发了几种用于北极有蹄类动物疾病监测的工具。在接下来的五年里，我将把头发皮质类固醇添加到这个健康评估工具库中。在生长过程中掺入毛发或羽毛中的皮质类固醇可以作为中长期压力的综合、回顾性生物标志物和生存的前瞻性标志物。灰熊的毛发皮质醇在前一年夏天鲑鱼的获取受到限制时升高，而秋季麻雀羽毛中皮质类固醇浓度升高则预示着越冬死亡率。麝牛有两种类型的毛皮，可能提供不同的时间措施的压力。每年夏天生长的qiviut（底毛）和次年春天完全脱落是一个可能的年度指标的压力。一年四季生长并持续多年的保护毛应该反映了几年来的累积压力。我将首先建立和验证测量qiviut和guard头发皮质类固醇的方法（目标1），然后使用不同种群轨迹上的三个麝牛种群（增加，减少，最近下降），每年抽样4年，测试这与不同的短期和长期个人健康指数的关系（物镜2），包括体型和状况、繁殖力、传染病多样性和丰度。然后，我将利用这些麝鼠种群，测试qiviut和guard毛皮质类固醇以及其他健康指标如何随几个关键的天气、气候和栖息地因素而变化（物镜，3）。这项工作将为三个麝牛种群建立全面的健康和传染病多样性基线，测试哪些健康指数或健康指数组合最能反映种群的整体健康状况，并评估气候和栖息地驱动因素与健康之间的关系。最终，这将产生对疾病生态学的新见解，并将制定跟踪个人和群体健康的方法和综合措施，并了解麝牛对自然和人为环境变化的适应能力。

Climate change in the Arctic is impacting the livelihoods, health, and lifestyles of aboriginal peoples, and the survival of animals on which they depend for food and their traditional cultures. Recent warming has led to northern range expansion of southern animals and their pathogens, altered host-parasite interactions, and emergence of disease. Further, an increasing human footprint in the Arctic (mineral and gas exploration/development, new shipping routes, increased research activities and tourism) is irreversibly altering ecosystems and exacerbating climate-mediated stress for wildlife.*Since 2008, my group has been investigating emerging diseases and mortality events in muskoxen in the Canadian Arctic archipelago. These include (i) multiple severe, widespread mortality events associated with Erysipelothrix rhusiopathiae, a bacteria not previously reported in muskoxen, nor in the Arctic, (ii) invasion and rapid range expansion of two nematode lungworms on the Arctic archipelago, and, (iii) new in 2013, severe ecthyma, or `orf' like lesions in muskoxen on Banks Island. Concurrently, recent surveys and anecdotal evidence indicate that muskox numbers have declined significantly in some of these regions. Together, these events suggest changes in ecological conditions and stressors culminating in disease and mortality with population level impacts. *The overall goal of this research is to develop and test integrative measures for health assessment of muskoxen that can be implemented through community-based monitoring and used to understand and monitor the sensitivity of muskoxen to environmental changes. *Previously, I developed several tools for disease surveillance in Arctic ungulates. Through the next five years I will add hair corticosteroids to this arsenal of health assessment tools. Corticosteroids incorporated into hair or feathers during growth can serve as integrated, retrospective, biomarkers of medium to long term stress and prospective markers of survival. Hair cortisol in grizzly bears is elevated when access to salmon the previous summer was limited and elevated corticosteroids concentrations in sparrow feathers in the fall predict over-wintering mortality. Muskoxen have two types of fur that may provide different temporal measures of stress. The qiviut (undercoat) growing each summer and fully shed the following spring is a probable annual indicator of stress. Guard hairs growing throughout the year and persisting over years should reflect cumulative stress over a period of several years. I will first establish and validate methods for measuring qiviut and guard hair corticosteroids (Obj.1), and then using three muskox populations on different population trajectories (increasing, decreasing, and recently declined), sampled annually for 4 years, test the relationship of this to different short and long term indices of individual health (Obj. 2), including body size and condition, fecundity, and infectious disease diversity and abundance. Then, using these same muskox populations, I will test how qiviut and guard hair corticosteroids, and other health indices, vary with several key weather, climate, and habitat factors (Obj. 3). This work will establish comprehensive baselines of health and diversity of infectious disease for three muskox populations, test which individual or combinations of health indices best reflect the overall health of a population, and evaluate the relationship between climate and habitat drivers and health. Ultimately this will generate new insights into disease ecology and will develop methodologies and integrative measures for tracking individual and population health and understanding the resilience of muskoxen to natural and anthropogenic environmental change.