Ecology and behavior
Amphibians are the most threatened group of vertebrates, yet we know very little about most species because they are small, secretive, and difficult to study. I use detailed field studies and lab experiments to investigate the ecology, evolution, and behavior of rare and common species, and make recommendations to improve conservation efforts for these species. My research has focused on the gopher frog (Lithobates capito) in Florida and the dusky gopher frog (Lithobates sevosus) in Mississippi, which have both declined due to habitat loss and degradation, Australian rainforest frogs (Litoria spp.) that are threatened by the disease chytridiomycosis, and treefrogs (Hyla spp.) that are negatively affected by the introduced Cuban treefrog (Osteopilus septentrionalis) in Florida.

Disease ecology
The disease chytridiomycosis has driven the greatest loss of biodiversity caused by disease in recorded history. This emerging fungal disease has caused catastrophic declines or extinctions in hundreds of amphibian species around the world. I am interested in the drivers of chytridiomycosis, including the influences of frog behavior, environmental conditions, and their interactions with habitat structure. My goals are to understand (1) how thermal and hydric preferences influence infection risk, (2) how infected frogs alter their behavior, and the consequences of these changes, (3) how natural thermal regimes affect pathogen growth and reproduction, (4) how canopy openings, such as those created by severe storms, influence frog microclimates and infection risk, (5) how infections influence frog reproduction, and (6) how infection risk interacts with climate change.

Invasion ecology
​Biological invasions alter community structure and threaten biodiversity worldwide. Identifying the mechanisms underlying the invasion process can inform management decisions to reduce the abundance of invasive species and their impacts on invaded communities. The Cuban treefrog was accidentally introduced to the Florida Keys in the 1920s, and has been spreading north ever since. I am using a landscape experiment in conjunction with lab experiments to investigate mechanisms facilitating this invasion. I am also evaluating behavioral and physiological traits of Cuban treefrogs that are undergoing natural selection in their introduced range. This information will help us understand how this invasive species is impacting native ecosystems, how it is adapting to its introduced range, and where range expansion may occur in the future.

Urban ecology
Remnant natural areas within urban settings can provide important refuges for wildlife, substantially increasing local biodiversity. However, for many species, little is known about their persistence in urban areas. My latest research investigates biodiversity in urban forests to understand how abundance and distribution are related to vegetation, urban features, and patch size and isolation. I am using urban forests in the greater Memphis region as a model system. Understanding relationships between biodiversity and habitat characteristics can help us manage populations and their habitats to maintain ecosystem function in urban areas.


Collaborators
Ross Alford - James Cook University
Steve Johnson - University of Florida
David Pike - Unaffiliated
Steve Reichling - Memphis Zoo
Jason Rohr - University of Notre Dame
Lin Schwarzkopf - James Cook University

Green treefrog (Litoria caerulea)

Gopher frog (Lithobates capito)

Green-eyed treefrog (Litoria serrata)

Invasive Cuban treefrog (Osteopilus septentrionalis)

Copperhead (Agkistrodon contortrix) crossing a trail in an urban forest