Early life experiences can have dramatic effects on the phenotypes expressed later in life and ultimately impact fitness. We examined the impact of larval predators and competitors on the post-metamorphic morphology and survival of gray tree frogs. Not only did competitors and predators impact larval and metamorphic phenotypes, but competition grealy reduced survival several months after metamorphosis (Relyea and Hoverman 2003).

Prey are able to change a variety of traits under different environmental situations. For prey to survive and reproduce, they must integrate their phenotypic responses when challenged with environments that contain competitors (intraspecific and interspecific), different densities of predators, and multiple predator species. By understanding trait integration, we can address important questions in the ecology and evolution of plasticity. (Hoverman and Relyea, in review, Hoverman, Auld, and Relyea 2005).

Environmental conditions can change at any time in the development of an individual. While the ability to respond to temporal variation may be favored, phenotypic responses may be constainted by developmental windows. By addressing developmental questions, we can obtain a better understanding of the benefits and costs of phenotypic plasticity. (Hoverman and Relyea in review, Hoverman and Relyea, 2007).

Predators can impact prey by direct consumption (i.e. reducing their density) or through inducing phenotypic changes (i.e. inducible defenses). These impacts can cascade through larger communities that contain many predator and competitor species. A major quesition in ecology is what is the relative importance of cascades that occur via changes in density versus traits (DMII versus TMII)? I received an NSF dissertation improvement grant to address this question and I am currently working on this manuscript.

Simply stated, theory predicts that constant environments will select for phenotypic canalization (due to the cost of phenotypic plasticity) while variable environmens will favor the maintenance of phenotypic plasticity. We have developed a great system for addressing this theory and are well on our way to answering this question.

Ecological communities are challenged by a variety of factors including anthropomorphic factors such as pesticides. Because pesticides can enter aquatic communities in many ways, it is important to determine how they can alter the ecology of the system. By applying an ecological framework that includes direct effects and trait- and density-mediated indirect effects, ecotoxicologists can identify the mechanisms through which pesticides affect communities and ecosystems (Relyea and Hoverman in review, Relyea and Hoverman 2006; Relyea, Schoeppner and Hoverman 2005)

I can conduct research in a variety of ways. This is a 1000-L cattle tank used in my experiments. The recipe for constructing this miniature pond is very simple: water, dirt, and leaves. When combined, they result in a perfect aquatic ecosystem.

For my dissertation, I spent the summer 100 miles North of Pittsburgh at the Pymatuning Laboratory of Ecology (PLE). This facility has plenty of space to conduct outstanding research projects including laboratory and mesocosm studies. More importantly, I spent the summer in an area with plenty of places to fish.