I received degrees from Columbia and Michigan State Universities with the doctorate in 1972. I have held visiting academic appointments at the Australian National University and the University of North Carolina. I received the Mercer Award from the Ecological Society of America, and served as vice-president of the Society and as an Editor of Ecology and Ecological Monographs. I also have served on National Research Council boards and as a member of the scientific advisory board of the National Center for Ecological Analysis and Synthesis.
I am interested in the nature of species interactions and the consequences of these interactions to the structure of ecological communities. My currently research focuses on larval amphibian communities as a model system to address these questions. My general approach has been to combine experiments in small replicate ponds or mesocosms with theory and field descriptive work in natural ponds.
A major focus of this work has been to understand how animals behave in the face of conflicting demands, in particular those associated with foraging gain/predation risk tradeoffs, and how these individual behaviors are manifest in community phenomena. For example, we have asked how the effects of predators on the phenotype (behavior, morphology, etc.) of prey species responding to such gain/risk tradeoffs are transmitted indirectly (i.e., trait-mediated indirect effects) to other species in simple food webs.
We have shown that larval odonate predators cause both behavioral and morphological changes in anuran larvae and that these trait effects can have as large or larger indirect effects on other species in the food web as the effect of the predator killing prey. We are exploring ways of incorporating such high-order effects in community theory. We also study tradeoffs that arise in species typically found on different regions of environmental gradients, in particular how performance at low resources/habitat quality trades off with performance at high resources/habitat quality and what traits of species are involved.
The backdrop for much of this experimental work is provided by patterns in anuran and macroinvertebrate community structure in natural ponds on the University's E. S. George Reserve. We have a long-term project quantifying densities and population trends in both amphibian larvae and macroinvertebrates in 37 natural ponds on the reserve. These ponds encompass wide environmental gradients of pond hydroperiod, forest canopy cover, and water body size that affect species' distributions.
Other interests of mine and those of students in my laboratory include the exploration of phenotypic plasticity in behavior and morphology of amphibian and odonate larvae, evolutionary responses of prey to different predator communities and size-structured interactions. Finally, I have a long-standing interest in the evolution of complex life cycles and the factors that influence size at metamorphosis in amphibians.