Abstract.

Disease and predation are both highly important in ecology, and pathogens with multiple host species have turned out to be common. Nonetheless, the interplay between multi-host epidemics and predation has received relatively little attention. Here, we analyse a model of a predator-prey system with disease in both prey and predator populations and determine reasonable parameter values using allometric mass scaling relations. Our analysis focuses on the possibility of extinction events rather than the linear stability of the model equations, and we derive approximate relations for the parameter values at which we expect these events to occur. We find that if the predator is a specialist, epidemics frequently drive the predator species to extinction. If the predator has an additional, immune prey species, predators will usually survive. Coexistence of predator and disease is impossible in the single-prey model. We conclude that for the prey species, carrying a pathogen can be an effective weapon against predators, and that being a generalist is a major advantage for a predator in the event of an epidemic affecting the prey or both species.

Graphical abstract

中文翻译：

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捕食者和病原体的不安共存。

摘要。

疾病和捕食在生态上都非常重要，事实证明，具有多种宿主物种的病原体很常见。尽管如此，多宿主流行病与捕食之间的相互作用却很少受到关注。在这里，我们分析了具有捕食者和捕食者种群的疾病的捕食者—食饵系统的模型，并使用异速质量比例关系确定了合理的参数值。我们的分析着眼于灭绝事件的可能性，而不是模型方程的线性稳定性，并且我们推导出了预期这些事件发生的参数值的近似关系。我们发现，如果捕食者是专家，那么流行病通常会导致捕食者物种灭绝。如果捕食者具有其他免疫猎物，捕食者通常会生存。在单一猎物模型中，捕食者与疾病并存是不可能的。我们得出结论，对于猎物物种而言，携带病原体可以作为抵抗捕食者的有效武器，而通才是捕食者在流行病影响猎物或两个物种时的主要优势。

图形概要