DISSERTATION RESEARCH:Understanding effects on climate change on parasitism in small mammals

令人吃惊的是，人类的死亡率很大一部分是由传染病造成的。了解寄生虫多样性的模式和疾病传播的动态是至关重要的。目前对气候如何改变寄生虫分布和多样性的基本模式知之甚少。该项目将利用山区从低海拔到高海拔的变化来模拟气候变化。该研究将描述寄生虫的分布，并研究沿这一梯度影响寄生虫多样性的因素。结果将把气候变化、寄生虫多样性和疾病联系起来。该项目将推动公共卫生和政策努力，以减少疾病随着气候变化而增加的风险。美国国家地理学会和史密森学会将建立公开的数据库，以促进未来在物种多样性高的地区进行研究。这项研究将加强与肯尼亚研究人员的合作，并将让美国学生参与实地工作。研究人员还将与加州少数民族参与联盟合作，在数据分析和疾病生态学方面指导来自经济弱势和其他代表性不足群体的学生。本项目将探讨气候变化对寄主饮食、多样性和密度的影响。研究结果将有助于建立所需的预测框架，以了解气候变化将如何影响野生动物及其寄生虫。研究人员将使用先前从30种小型哺乳动物中收集的样本来量化每个宿主的饮食和胃肠道寄生虫群落。样本沿着肯雅山的海拔梯度收集，该梯度近似于气候变化预期的非生物条件变化。寄生虫将被计数和识别，一个子集将被条形码识别隐种和新物种。宿主的饮食和营养水平将通过ä15N稳定同位素化学来确定，并通过复合特定稳定同位素分析和宿主肠道内容物的目视检查来验证。在控制宿主丰度和多样性后，这些数据将用于测试长期公认的自由生活物种丰富度模式是否适用于沿海拔梯度的寄生虫丰富度。寄生虫多样性模式的机制将通过研究寄主饮食、多样性和密度如何影响寄生虫丰富度来探索。预计气候梯度会改变寄生虫的多样性和每个宿主的寄生虫数量（强度）。生物海拔高度效应（宿主密度、多样性和饮食）对寄生虫强度的相对重要性将在多个海拔高度的丰富宿主中进行检验。这一分析将在多种寄生虫中重复进行，以测试寄生虫对不断变化的宿主和气候条件的反应的普遍性。

A surprising large percentage of human mortality is caused by infectious disease. Understanding patters of parasite diversity and the dynamics of disease transmission is critical. Little is currently known about how climate alters basic patterns of parasite distribution and diversity. This project will use changes from low to high elevations on a mountain to mimic climate change. The research will describe the distribution of parasites and examine the factors affecting parasite diversity along this gradient. Results will link climate change, parasite diversity, and disease. The project will advance public health and policy efforts to reduce risks that disease will increase with climate change. The National Geographic Society and the Smithsonian Institution will host publicly available databases that will facilitate future studies in a region of high species diversity. The research will strengthen collaborations with Kenyan researchers and will engage American students in field work. The investigators will also collaborate with the California Alliance for Minority Participation to mentor students from economically disadvantaged and otherwise under-represented groups in data analysis and disease ecology.This project will explore how climate driven changes in host diet, diversity, and density affect parasitism. Results will contribute to the predictive framework needed to understand how climate change will affect wildlife and their parasites. The investigators will use previously-collected samples from 30 species of small mammals to quantify each host's diet and gastrointestinal parasite community. Samples were collected along an elevational gradient on Mount Kenya that approximates changes in abiotic conditions expected with climate change. Parasites will be counted and identified and a subset will be barcoded to identify cryptic and novel species. Host diet and trophic level will be determined using ä15N stable isotope chemistry and validated with compound specific stable isotope analyses and visual inspection of host gut contents. Controlling for host abundance and diversity, these data will then be used to test if long-recognized patterns in free-living species richness apply to parasite richness along elevational gradients. The mechanisms responsible for patterns in parasite diversity will be explored by examining how host diet, diversity, and density affect parasite richness. Climatic gradients are expected to alter both parasite diversity and the number of parasites per host (intensity). The relative importance of biotic elevation effects (host density, diversity and diet) on parasite intensity will be examined for parasites that occur in hosts abundant at multiple elevations. This analysis will be repeated across multiple parasites to test the generality of parasite responses to changing host and climatic conditions.