When environmentally persistent pathogens transform good habitat into ecological traps

Authors:

• Clinton B. Leach, Department of Biology, Colorado State University
• Colleen T. Webb, Department of Biology, Colorado State University
• Paul C. Cross, U.S. Geological Survey, Northern Rocky Mountain Science Center

Abstract

The benefits of high quality habitat for host persistence may be modulated by the presence of an environmentally persistent pathogen. In some cases, the presence of environmental pathogen reservoirs on high quality habitat may lead to the creation of ecological traps, wherein host individuals preferentially colonize high quality habitat, but are then exposed to increased infection risk and disease-induced mortality. We explored this possibility through the development of a stochastic patch occupancy model, where we varied the pathogen's virulence, transmission rate, and environmental persistence as well as the distribution of habitat quality in the host metapopulation. This model suggests that for pathogens with intermediate levels of spread, high quality habitat can serve as an ecological trap, and can be detrimental to host persistence relative to low quality habitat. This inversion of the relative roles of high and low quality habitat highlights the importance of considering the interaction between spatial structure and pathogen transmission when managing wildlife populations exposed to an environmentally persistent pathogen.

Repository

This repository holds the code, data, and manuscript draft for the above project, currently in prep for submission.

The directories are:

• Code: R functions for simulating metapopulation model and collecting output.
• Analysis: Scripts to set up and run metapopulation model and explore, analyze, and plot output.
• Output: .RData files generated by simulation scripts in analysis.
• Manuscript: draft of manuscript for publication.

See README files within Code and Data directories for additional information.