Peacock Stephanie J, Bouhours Juliette, Lewis Mark A, Molnár Péter K
Ecology and Evolutionary Biology, University of Toronto, Canada; Biological Sciences, University of Alberta, Canada.
Mathematical and Statistical Sciences, University of Alberta, Canada.
Theor Popul Biol. 2018 Mar;120:29-41. doi: 10.1016/j.tpb.2017.12.005. Epub 2018 Jan 6.
Spatial variability in host density is a key factor affecting disease dynamics of wildlife, and yet there are few spatially explicit models of host-macroparasite dynamics. This limits our understanding of parasitism in migratory hosts, whose densities change considerably in both space and time. In this paper, we develop a model for host-macroparasite dynamics that considers the directional movement of host populations and their associated parasites. We include spatiotemporal changes in the mean and variance in parasite burden per host, as well as parasite-mediated host mortality and parasite-mediated migratory ability. Reduced migratory ability with increasing parasitism results in heavily infested hosts halting their migration, and higher parasite burdens in stationary hosts than in moving hosts. Simulations reveal the potential for positive feedbacks between parasite-reduced migratory ability and increasing parasite burdens at infection hotspots, such as stopover sites, that may lead to parasite-induced migratory stalling. This framework could help understand how global change might influence wildlife disease via changes to migratory patterns and parasite demographic rates.
宿主密度的空间变异性是影响野生动物疾病动态的关键因素，但目前关于宿主-大型寄生虫动态的空间明确模型却很少。这限制了我们对迁徙宿主中寄生虫感染情况的理解，因为迁徙宿主的密度在空间和时间上都会发生显著变化。在本文中，我们开发了一个宿主-大型寄生虫动态模型，该模型考虑了宿主种群及其相关寄生虫的定向移动。我们纳入了每个宿主寄生虫负荷的均值和方差的时空变化，以及寄生虫介导的宿主死亡率和寄生虫介导的迁徙能力。随着寄生虫感染程度的增加，宿主迁徙能力下降，导致感染严重的宿主停止迁徙，并且静止宿主中的寄生虫负荷高于移动宿主。模拟结果揭示了在感染热点地区（如中途停歇地），寄生虫导致的迁徙能力下降与寄生虫负荷增加之间存在正反馈的可能性，这可能导致寄生虫诱导的迁徙停滞。该框架有助于理解全球变化如何通过改变迁徙模式和寄生虫种群动态率来影响野生动物疾病。
