Current and Recent Areas of Research

Interactions between sexual and natural selection driving morphology and behavior

Sexually selected traits evolve in a complex ecological context, with interactions between selective pressures driving (and constraining) the evolution of these traits. Our research in this area focuses primarily on fiddler crabs, in the context of their extreme sexual dimorphism and complex mating system. We have examined the thermoregulatory function of the greatly enlarged male claw, the role of sexual selection via endurance rivalry in shaping behavioral responses to thermal stress, and the selective pressures driving territory preferences.

Abiotic and biotic modulation of behavioral tradeoffs

Animals are constantly confronted with behavioral tradeoffs, as many behaviors are temporally incompatible. For example, in fiddler crabs, there is a clear and direct tradeoff between thermoregulatory behavior and courtship behavior, and sexual selection via endurance rivalry favors individuals that are able and willing to endure harsh conditions in pursuit of mating opportunities. Our work in this area focuses on the abiotic and biotic factors that modulate the strength of these tradeoffs, flexible decision-making strategies that take into account the relative costs and benefits of the various behavioral options over multiple timescales, and the consequences of behavioral choice both for immediate performance and overall fitness.

Ecology, physiology, and behavior of migration

Marine organisms often have migratory life cycles, with migratory ability optimized by complex interactions between physiological changes, orientation mechanisms, and movement behaviors. My long-term research interests in migratory ecology are focused on the mechanisms that optimize migratory ability of both adults and larvae under a variety of biotic and abiotic conditions and the implications of these mechanisms for the abundance and distribution of the species. We focus primarily on species that use selective tidal-stream transport to increase migratory ability or decrease the energetic costs of migration. This works involves a combination of laboratory behavioral experiments to examine migratory mechanisms and decision rules and multiple telemetry techniques to monitor migratory behavior, routes, and timing in the field.

Behavioral, physiological, and life history responses to thermal stress and climate change

Ocean temperatures and coastal climates are rising, and organisms will a number of challenges including changes in heat and desiccation (for intertidal organisms) stress, synchronization of mating and gamete cycles, and shifts in phenology. The degree to which species are impacted, however, will depend on the species’ adaptability, acclimation ability, and capacity for behavioral thermoregulation, all of which can buffer effects of climate change. Research in this area has focused on understanding responses to thermal shifts and thermal stress in the context of predicting future responses to climate change, focusing on a number of crustaceans including fiddler crabs and blue crabs.

Population-level consequences of phenotypic plasticity in crustacean reproduction

Phenotypic plasticity in maternal investment and reproductive traits can be driven by environmental fluctuations or changes in population density and demography, and can have important consequences for performance and fitness of offspring. These effects can scale up to affect abundance, distribution, and population dynamics. Crustaceans in particular exhibit an astounding diversity of reproductive strategies and degrees of maternal investment, and often show remarkable plasticity in response to environmental conditions. Research in this area is focused on phenotypic plasticity in reproductive traits and behaviors in response to exploitation, environmental stochasticity, climate change, and range shifts (including both anthropogenic and climate-triggered invasions of novel habitats) and also considers the impacts of reproductive plasticity and maternal investment on performance and survival of early life history stages, stages that typically experience high mortality.