Research

I am interested in theoretical questions in life history, population, conservation, and community ecology with general and practical applications.

At LSU as a postdoctoral researcher, I worked with Bret Elderd to understand how variation from the individual to the landscape scale alters epizootic dynamics using a lepidopteran (Fall Armyworm) system. My projects at LSU involved the implications of stage-structured cannibalism for epizootic dynamics, the consequences of agricultural monoculture for natural and controlled epizootics in agricultural pest populations, and how infection alters individual and group behavior and movement across the landscape.

For my dissertation, I explored how carry-over effects of natal habitat quality can affect population and community dynamics using flour beetles (Tribolium sp.), freshwater pond communities and modelling.

As a masters student I examined how larval experiences in frogs carried over to affect juvenile performance in temperate and neotropical treefrog species.

I also use modelling approaches with R, NetLogo,  and other programs to investigate other cool questions such as extinction risk and how cannibalism differs from other sources of mortality in changing the dynamics of stage structured populations.

 

Flour Beetles

The Tenebrionid beetles in the genus Tribolium make great lab animals. They are easy to keep in various kinds of flour, and importantly, their traits can be strongly influenced by natal habitat. Previous work suggested this might be possible, but I discovered that the kind of flour a beetle develops in can have important implications for their adult body size, fecundity, cannibalism behavior and response to habitat quality as a adult. These differences can affect the offspring of beetles as well. I found that these carry-over and maternal (cross generational) effects can strongly effect population dynamics (Van Allen and Rudolf 20The American Naturalist), and can in some cases reverse or modify the dynamics of interspecific competition (published in the Journal of Animal Ecology). With a great undergrad researcher, Preeya Bhavsar at Rice, I found how carry-over effects and population density can interact to alter dispersal dynamics in interesting ways (published in Oikos). I also tested how carry-over effects and dispersal rates interact to affect metacommunity dynamics across landscapes with heterogeneous habitat quality (published in PNAS). Habitat quality variation is ubiquitous in natural and anthropogenically modified systems. Carry-over effects occur in insects, like flour beetles, but also in vertebrates, other invertebrates and plants. Exploring how carry-over effects alter species interactions and community dynamics is important for understanding how natural communities work and predicting the spread or decline of populations across the landscape.

Freshwater Pond Communities

Eutrophication of surface waters (excess plant productivity caused by nutrient enrichment of water) is one of the largest water quality issues facing the world today. At the same time,  invasive species are homogenizing the biodiversity of freshwater habitats around the world and altering the ecological processes and services that they provide. I tested whether eutrophication of freshwater habitats could promote the spread and impacts of invasive species such as freshwater snails through carry-over effects. Carry-over of the enhanced condition that these invaders acquired from abundant food in their original eutrophic habitat could increase their success in the newly invaded wetland. I examined whether the long term effects of this increased invasion success could be higher numbers of invaders, stronger impacts to the invaded environment, and an increased possibility of furthering the invasion through more and higher quality individuals dispersing to other habitats. I found that carry-over effects of eutrophic habitat increased the population growth and individual growth rates of the offspring of invading snails, leading to some indirect effects on other species in the invaded communities. This has clear implications that increased eutrophic freshwater habitat can increase the spread and impact of invasive species.

Hylid Frogs

During my master’s degree at Virginia Commonwealth University with James Vonesh, I was lucky enough to complete two similar field/lab project with hylid frogs. One in Virginia using Spring Peepers (Pseudacris crucifer) and one in Panama with Red-Eyed Treefrogs (Agalychnis callidryas). Red-Eyed Treefrogs are iconic and photogenic, but Peepers win in terms of “personality”, at least during the juvenile stage. In both experiments I asked whether increased access to food during the larval period enhanced juvenile performance beyond their effects on size and timing of metamorphosis. Sure enough, a higher quality environment during the larval period increased growth rates and survival of juvenile frogs independently of size at metamorphosis and under common conditions. This work has since been published in Oecologia.