Research Interests

Personnel | Prospective Students | Publications

The theme of my research is to investigate conservation issues while extending theory in ecology. How do anthropogenic stressors alter an individual’s response to conspecifics, competitors, resources, pathogens and predators, and how do these differential responses between individuals alter community dynamics?

My current research integrates many fields of study to investigate the causes of amphibian declines worldwide. Amphibians represent an ideal model organism to investigate the disparate effects of global change because they are found worldwide and are susceptible to several of the leading contributors to global change: habitat modification, climate change, invasive species, disease, and contaminants. My research has focused primarily on understanding the impacts of multiple stressors, both biotic (predators and pathogens) and abiotic (pollutants and habitat alterations), on aquatic communities. I believe this research has benefits to advance not only the theory of the relevant fields but also the conservation of the species involved. Therefore my goal is to not only observe the negative impacts stressors have on organisms within a community, but also to learn about the changes in community dynamics that result.

Currently, I am working to determine the prevalence of a chytrid fungus (Batrachochytrium dendrobatitis) in amphibians found throughout the Midwest. In particular, I am interested in how pesticides might alter susceptibility in amphibian species to this deadly pathogen.

My post-doctoral research examined the effects of the combined stress of low concentration pesticide exposure and the presence of viral disease in tiger salamanders. I found evidence that pesticide exposure increases susceptibility to disease. In addition to pesticides, the presence of a predator also drastically increases mortality in virus exposed animals. Click here to see a poster presentation by one of my undergraduate researchers.

My dissertation research focused on understanding the influences pesticides have on ecologically important behaviors, particularly in amphibians. I studied the relative impacts of low pesticide concentrations on predators and prey and possible influences on declining amphibian populations throughout California. I have found significant behavioral alterations in predator-prey interactions between two species of frogs (Pseudacris regilla and Rana boylii) with crayfish and fish predators. I have also found significant alterations in competitive interactions between the same two species of frogs.

I have also been involved in several different projects involving research on invasive crayfish. Our Sea grant project investigated the factors influencing the spread and impact of two species of non-native crayfish (Procambarus clarkii and Pascifastacus leniusculus). In conjunction with Lee Kats and Pepperdine University, I was also currently involved in a restoration project to attempt removal of crayfish from a southern California coastal stream.

I am currently in the midst of writing up several papers on these topics and expect to submit several more manuscripts by years end. Please feel free to contact me to obtain the latest findings of my research.

USD Press release on Ecology Letters Paper