RESEARCH IN THE HOPKINS LAB

Our research program has two broad focal areas, one centered in basic science and the other dealing with more applied ecological problems. The first focal area deals with parental effects on offspring fitness. In recent years we have specifically focused on incubation behavior in birds, using wood ducks and tree swallows as precocial and altricial avian models, respectively.

Our second area of focus is how anthropogenic disturbances, particularly pollution, alter the ability of birds and herpetofauna to interact appropriately with their environment. Specific emphasis is placed on how pollutants influence maternal health and the fitness consequences of maternal transfer of teratogenic compounds.

 

 

Current Projects

Conservation Physiology and Ecology of Hellbenders

This giant, totally aquatic salamander inhabits cool streams in the Appalachian and Ozark Mountains.  Populations are under threat from changes in land use, including watershed development and destruction of forested riparian areas.

Maternal Effects and Life History Evolution

Maternal effects are maternal traits that influence offspring phenotype via non-genetic pathways. In many cases maternal effects can have profound influences on offspring, often rivaling the effects of genetic contributions to offspring fitness.

Scaling individual-level effects of pollution to metapopulation-scale processes

Our lab has examined the effects of environmental mercury (Hg) exposure through multiple pathways throughout the life cycle of a common and widespread amphibian, the American toad (Bufo americanus).

Mercury Contamination and Trophic Position in Turtles

Mercury is a concern for fish, wildlife, and human health because of its toxicity and tendency to bioaccumulate and biomagnify in food webs. We examined three aquatic species that differ drastically in their feeding ecology, providing an opportunity to assess the influence of trophic niche on mercury accumulation.

Maternal Transfer of Mercury in Turtles

Mercury has been shown to maternally transfer from females to their offspring in a variety of vertebrates, resulting in decreased reproductive output, reduced hatching success, and lethal and sublethal effects on offspring. Little is known about the reproductive effects of mercury in turtles.

 

Past Projects

Effects of Pollution on Songbird Physiology

To explore the potential effects of mercury on adrenal and thyroid function during biological development, we sampled nestling tree swallows (Tachycineta bicolor) near the mercury-contaminated South River in VA, and at nearby reference sites where the only known source of mercury is atmospheric deposition.

Effects of Maternally Transferred Mercury on Aquatic Snakes

In this past project, our research examined mercury accumulation and maternal transfer in watersnakes inhabiting contaminated aquatic habitats and the effects of mercury on female reproductive characteristics and offspring fitness.

Maternal Transfer of Mercury in Amphibians

In this past project, we used the American toad, Bufo americanus, as a model species for our work. We used a combination of field and laboratory techniques such as experimental mercury-contaminated and control diets, aquatic mesocosms, and terrestrial enclosures to determine immediate and latent effects of Hg contamination amphibians.

Effects of Coal Combustion Wastes on Reproduction

This project examined the effects of the Kingston Coal Ash Spill on both aquatic (turtles) and terrestrial (tree swallows) consumers. We studied the additive and/or interactive (synergistic and antagonistic) impacts that complex mixtures of contaminants have on exposed wildlife.