Can group living and the influence of Allee Effects explain infectious disease vulnerability in social species? Emergence of M. mungi in the cooperative breeding banded mongoose

许多野生动物都是群居动物，群居对它们的生存至关重要。群体生活和个体之间的合作通过促进繁殖、提高觅食成功率和增强抵御捕食者的能力来提高群体表现。然而，众所周知，群体的相对规模也很重要。如果一个群体中的个体数量减少，其收益也可能减少，这可能会威胁到群体的持久性。这种现象被称为Allee效应：当个体的数量或密度由于生态或遗传因素（或两者的结合）而低于某一阈值时，一个种群或群体面临灭绝的风险增加。另一方面，人口增加和人口密度增加也可能造成问题，因为它们使群体更容易感染传染病。Allee效应已被广泛研究，并且已知对野生动物生态学具有重要意义，但Allee效应与疾病出现之间的联系却知之甚少。然而，了解群体大小和Allee效应如何驱动传染病相互作用对于濒危社会物种的保护和管理以及感染群体生活物种并威胁人类和动物健康的新出现疾病的控制至关重要。在由该奖项资助的研究中，凯瑟琳·亚历山大博士（弗吉尼亚理工学院州立大学）和她的团队将采用创新的方法来解决这一关键的知识差距。他们将把实地经验研究与数学建模结合起来，调查和确定影响群居物种疾病传播的原则和过程。他们还将建立与综合博士后和研究生培训计划相联系的国际科学网络，以培养具有国际新发传染病研究技能的多学科科学家，这是一个日益需要的领域。该项目的其他教育组成部分包括一个结构化的K-7教育方案，以培养研究地区儿童对传染病生态学的兴趣和了解。该研究项目还将建立一个基础，通过互动讲座和包括播客和社交媒体在内的当代学习媒体，促进博茨瓦纳青年与美国少数民族本科生之间的合作学习。该项目将把博茨瓦纳的学生与美国的学生联系起来。在博茨瓦纳，因艾滋病毒/艾滋病和结核病导致的传染病死亡很常见，而美国很少发生大规模传染病。学生将在广泛的层面上探讨疾病的起因和控制，重点是全球共同的需求。这种方法的目的是加强跨文化理解和国际领导能力，以少数民族为主导的新发传染病生态学的科学发现。为了研究Allee效应和传染病出现之间的联系，亚历山大和她的团队将以他们对博茨瓦纳北部带状猫鼬（Mungos mungo）的长期研究为基础。高度群居的带状猫鼬受到一种新型结核（TB）病原体——芒氏分枝杆菌的威胁。这种病原体与人类结核病病原体非洲支原体密切相关，并在带状猫鼬中造成高死亡率，威胁到较小社会群体的持续存在。研究小组将采用一种综合的方法，将宿主和病原体的分子遗传学研究与种群生物学和猫鼬社会群体的行为生态学研究联系起来，这些研究发生在景观的受保护和不受保护的地区。他们将使用这个实证研究系统来调查和确定决定传染病和Allee效应之间相互作用结果的主要因素、过程和阈值。研究结果将用于建立一个概念框架和推进知识和理论，这些知识和理论可用于确定是否以及何时应将Allee效应纳入群体生活物种的传染病模型，以及如何计算表征这些相互作用。研究结果将对涉及传染病传播的社会野生动物物种的管理以及对濒危群居物种的保护具有重要意义，这些传染病对动物和公众健康都具有重要意义。

Many wildlife species are social and live in groups, which provides benefits critical to survival. Group living and cooperation between individuals improve group performance by enhancing reproduction, improving foraging success, and increasing the ability to defend against predators. However, it is also known that the relative size of the group matters. If the number of individuals in a group decreases, the benefits also may decrease, potentially threatening group persistence. This phenomenon is referred to as the Allee effect: a population or group is at an increased risk of extinction when the number or density of individuals falls below a certain threshold due to either ecological or genetic factors (or a combination of the two). On the other hand, increased populations and increased population densities also can be problematic because they enhance group vulnerability to infectious disease. Allee effects have been widely studied and are known to have important implications for wildlife ecology but the connection between Allee effects and disease emergence is much less well understood. Understanding how group size and Allee effects drive infectious disease interactions is critical, however, to the conservation and management of endangered social species as well as to the control of emerging diseases that infect group-living species and threaten both human and animal health. In the research funded by this award, Dr. Kathleen Alexander (Virginia Polytechnic Institute State University) and her team will take an innovative approach to address this critical knowledge gap. They will integrate empirical field studies with mathematical modeling to investigate and identify principles and processes that influence disease transmission in group-living species. They also will establish international scientific networks linked to a comprehensive postdoctoral and graduate student-training program to produce multidisciplinary scientists with skills in international emerging infectious disease research, an area of increasing need. Other education components of the project include a structured K-7 educational program to foster interest and increase understanding of infectious disease ecology in children in the study region. The research project will also establish a foundation to foster collaborative learning between Botswana youth and undergraduate minority students in the United through interactive lectures and contemporary learning media including podcasts and social media. This program will link students from Botswana, where infectious disease deaths from HIV/AIDS and tuberculosis are common, and the United States where pandemic infectious disease is rarely experienced. Students will explore disease causation and control on a broad level with a focus on the common global need. This approach is directed at strengthening cross-cultural understanding and international leadership capacity in minority-driven scientific discovery in the ecology of emerging infectious disease. To study the connection between Allee effects and infectious disease emergence, Alexander and her team will build on their long-term study of banded mongoose (Mungos mungo) in northern Botswana. The highly social banded mongoose is threatened with a novel, emerging tuberculosis (TB) pathogen, Mycobacterium mungi. This pathogen is closely related to the human TB pathogen, M. africanum, and causes high levels of mortality among banded mongoose, threatening the persistence of smaller social groups. The research team will take an integrated methodological approach that links molecular genetic studies of the host and pathogen with population biology and behavioral ecology studies of mongoose social groups that occur across both protected and unprotected areas of the landscape. They will use this empirical study system to investigate and identify dominant factors, processes, and thresholds that determine the outcome of the interaction between infectious disease and Allee effects. Research results will be used to develop a conceptual framework and advance knowledge and theory that can be used to determine if and when Allee effects should be included in models of infectious disease in group-living species and how these interaction should be computationally characterized. Results will be important to the management of social wildlife species involved in transmission of infectious diseases of importance to both animal and public health as well as to the conservation of endangered group-living species.