Ecol Evol. 2012 Jul;2(7):1398-407. doi: 10.1002/ece3.257.
Motivated by an array of infectious diseases that threaten wildlife populations, a simple metapopulation model (subpopulations connected by animal movement) is developed, which allows for both movement-based and environmental transmission. The model demonstrates that for a range of plausible parameterizations of environmental transmission, increased movement rate of animals between discrete habitats can lead to a decrease in the overall proportion of sites that are occupied. This can limit the ability of the rescue effect to ensure locally extinct populations become recolonized and can drive metapopulations down in size so that extinction by mechanisms other than disease may become more likely. It further highlights that, in the context of environmental transmission, the environmental persistence time of pathogens and the probability of acquiring infection by environmental transmission can affect host metapopulations both qualitatively and quantitatively. Additional spillover sources of infection from alternate reservoir hosts are also included in the model and a synthesis of all three types of transmission, acting alone or in combination, is performed revealing that movement-based transmission is the only necessary condition for a decline in the proportion of occupied sites with increasing movement rate, but that the presence of other types of transmission can reverse this qualitative result. By including the previously neglected role of environmental transmission, this work contributes to the general discussion of when dispersal by wild animals is beneficial or detrimental to populations experiencing infectious disease.
受一系列威胁野生动物种群的传染病的启发，我们开发了一个简单的集合种群模型（通过动物运动连接的亚种群），该模型允许基于运动和环境的传播。该模型表明，对于环境传播的一系列合理参数化，动物在离散栖息地之间的移动速度增加可能导致被占据的地点比例总体下降。这可能会限制救援效应确保局部灭绝的种群重新殖民的能力，并使集合种群的规模缩小，从而使其他机制（而非疾病）导致灭绝的可能性增加。它进一步强调，在环境传播的情况下，病原体的环境持续时间和通过环境传播获得感染的可能性会在定性和定量两方面影响宿主集合种群。该模型还包括了来自替代储主的额外溢出感染源，并且对所有三种类型的单独或组合传播进行了综合分析，结果表明，随着移动速度的增加，基于移动的传播是占据地点比例下降的唯一必要条件，但其他类型的传播的存在可能会使这一定性结果发生逆转。通过纳入以前被忽视的环境传播作用，这项工作有助于一般讨论野生动物的扩散对遭受传染病的种群是有益还是有害。
