“The critical role of infectious disease in compensatory population growth in response to culling”

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Eleanor Tanner, Andy White, Peter W. W. Lurz, Christian Gortázar, Iratxe Díez-Delgado, and Mike Boots (July 2019)

The DOI will be https://dx.doi.org/10.1086/703437

Using mathematical models we show how culling populations harboring endemic disease can lead to compensatory growth

Wild boar (Sus scrofa).
(Credit: Christian Gortázar)

Abstract

Despite the ubiquity of disease in nature, the role that disease dynamics play in the compensatory growth response to harvesting has been ignored. We use a mathematical approach to show that harvesting can lead to compensatory growth due to a release from disease-induced mortality. Our findings imply that culling in systems that harbor virulent parasites can reduce disease prevalence and increase population density. Our models predict that this compensation occurs for a broad range of infectious disease characteristics unless disease induces long-lasting immunity in hosts. Our key insight is that a population can be regulated at a similar density by disease or at reduced prevalence by a combination of culling and disease. We illustrate our predictions with a system-specific model representing wild boar tuberculosis infection, parameterized for central Spain, and find significant compensation to culling. Given that few wildlife diseases are likely to induce long-lived immunity, populations with virulent diseases may often be resilient to harvesting.