CAREER: An Integrative Approach to Predicting Amphibian Chytridiomycosis in Space and Time

Tulane University, New Orleans LA

Investigators

Abstract

The seasonal cycles exhibited by many infectious diseases are a reminder of the effects of climate on host-pathogen interactions, yet the mechanisms that link environmental variation to epidemiological patterns are often poorly understood. A clearer understanding of the relationship between climate and host-pathogen interactions is needed to predict and mitigate the risks that infectious diseases pose to humans and wildlife. The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which has been linked to declines and extinctions of frogs worldwide and appears to be an important contributor to the ongoing amphibian extinction crisis. This project will contribute to our understanding of the epidemiology of this host-pathogen interaction by clarifying the behavioral and immunological mechanisms by which climatic variation shapes the risk of chytridiomycosis in amphibians. The project team will integrate research and education through the development of middle school, high school and university level curricula. Using the amphibian chytridiomycosis system as a model, they will develop learning modules centered on teaching how changes in climate, via their effects on physiology, can impact ecological processes. The project team will quantify the relationship between climate, host behavior and Bd susceptibility and use it to (1) make spatiotemporal predictions of disease risk and (2) teach K-12 and university students about the potential impacts of climate change on ecosystems. The research component of this project will assess (I) the effect of temperature on pathogenicity and immune defense, and (II) the effectiveness of a behavioral fever response in combating Bd infection using lab exposure experiments under a variety of thermal conditions. Concurrently, host body temperatures and available microclimates will be measured in the field to determine (III) how the opportunity for thermally-mediated host defense varies in space and time. Ultimately, the findings of objectives I - III will be used to develop biophysical models (IV) to predict where and when amphibians will be unable avoid or combat Bd, leaving them susceptible to mortality and declines. The education component of this project will use findings and techniques from the research to develop, employ, and evaluate new curricula for teaching the impacts of climate change on ecological processes. At the core of these curricula will be experiential learning and a "citizen science" approach, facilitating feedback from K-12 and university classrooms to the research.