Our work is focused on the conservation and ecology of amphibians (and reptiles), with interests at multiple scales – including population, community, and ecosystems – especially as they are affected by emerging infectious disease and global change. We have three major research sites: Panama, Illinois, and Appalachia. Much of this work is multidisciplinary, involving various collaborators from various fields. Many of our projects examine the interactions among amphibian hosts (tropical frogs, Illinois amphibians, Appalachian salamanders), Bd (the frog-killing fungus), and the environment to determine why some species decline, some go extinct, and others are not affected. Another group of projects determines the ecological impacts of amphibian population declines on other components of the aquatic and terrestrial ecosystems (TADS). A third group of interests involves science communication, policy and outreach aspects of these scientific projects.
Population Biology and Community Ecology
Many of our research interests center on the population biology and community ecology of amphibians. We are interested in determining the spatiotemporal variation in diversity and abundance of amphibians in various communities, studying comparative population demography, and quantifying the role of adult and larval amphibians in tropical and temperate ecosystems. In the Appalachians we are quantifying variation in species richness, abundance and ecology in the context of global climate change.
We have been working on determining the geographic and ecological patterns of amphibian declines in our three study areas. By analyzing patterns of decline among species and across many sites, we hope to predict future declines of other populations at other sites and to prioritize research and conservation actions. In Latin America, amphibian populations have suffered tremendous losses, many of which were apparently caused by disease from an aquatic frog-killing fungus, Batrachochytrium dendrobatidis (“Bd”). Bd is present in Illinois, but the effects on populations are not known. In both regions we are studying the prevalence of Bd in natural populations of amphibians and how ecology and environmental conditions vary individual and population responses to the fungus.
Trade, Invasives & Disease
We have begun developing projects that explore the role of trade in the movement of invasive pathogens. We are interested in understanding how trade affects the movement of diseases and invasive host species, but also the impacts of extraction on wild populations in the field.
In the Appalachians we are interested in understanding how disease and climate change may have affected population biology and community composition of plethodontid salamanders. We have established a 800 km long transect from MD to NC along which we have been surveying populations and communities. We are interested in quantifying changes in those populations and determining whether disease and/or climate are involved in observed changes. We are working on investigating interactions among disease, symbiotic microbes, and climate change across communities and populations.
Given the abundance and diversity of frogs and tadpoles at tropical sites, the dual role of amphibians in the food web (insectivorous adults and herbivorous tadpoles), and the bimodal life cycle (terrestrial adults and aquatic larvae) the loss of a large portion of the amphibian biomass might have big impacts on aquatic and terrestrial ecosystems. As part of an interdisciplinary team, we compared tropical mountain stream food web structure pre-and post-decline to determine the impact of amphibian declines on these ecosystems. We conducted small-scale removal experiments, quantified spatio-temporal variation in adult and larval amphibian assemblages, and are quantifying the trophic links among amphibians, lizards and snakes.We are interested in doing similar ecosystem work in the Appalachians where terrestrial salamanders are likely to influence the forest ecosystem.