Research Overview

Our lab is broadly interested in the evolutionary and ecological processes that generate phenotypic diversity. We mainly approach this topic from the perspective of behavioral ecology, addressing questions about the function and evolution of sexual traits, the causes of variability in the survival-reproduction tradeoff, and what drives individual variation in mate choice and competition. Working with some of the most environmentally sensitive taxa (amphibians and reptiles) has also led us to apply this individual-level framework to conservation. We aim to better understand the challenges species face in novel anthropogenic environments and their potential adaptations to these challenges.

Animal Signals and Communication

Several projects in the lab are focused on understanding how animals communicate, usually in a reproductive context. Reproductive traits - whether visual or acoustic - are signals that convey to receivers multiple types of information. Such signals are often the major determinants of an individual's seasonal or lifetime reproductive success. As anthropogenic activity causes animals' visual and acoustic environments to change, we also explore how these selective forces affect signaling behavior.

Reproductive Behavior and Constraints

A rich body of literature uses theoretical and modeling approaches to understand the link between mate choice or competition and individual fitness. Building from this base, we empirically test the connection of pre-mating decision making (e.g., who to mate with, how often, or how to compete for mate access) with variation in offspring fitness.

As environments change, so must reproductive strategies. Although mating itself typically is short relative to an individual’s lifespan, how animals behaviorally and physiologically respond to challenges before, during, and immediately after mating can have disproportionate effects on fitness. Consequently, selection within unpredictable environments has repeatedly led to the evolution of flexible, instead of hard-and-fast, tactics of mate choice and competition.

Tradeoffs and Anti-Predator Behavior

Behavior can be used to offset many of the high costs of conspicuous signals. We study the conflicting pulls of natural and sexual selection on individuals, and we test how intraspecific variation in this 'balancing act' can depend on sex and the environment. In addition, we explore the effect of variable environments (e.g., thermal, microhabitat, level of risk) on the mechanics of anti-predator behaviors, such as seeking underwater refugia, swimming, sprinting, and leaping.

Natural History

All of our group's work subscribes to the philosophy that natural history is key to the future of ecology. Without natural history as a foundation, we risk theorizing with no basis in reality, and our policy and conservation efforts are stunted. Becoming proficient in natural history is a time investment. It's not trendy or a funding priority. But it is the only way we can move forward as ecologists: Why Ecology Needs Natural History

The Swierk Lab is privileged to work on land that constitutes the the traditional territories of the Ho-de-no-sau-nee-ga (Haudenosaunee) and Onundagaonoga (Onondaga) in the USA,
the Tjer-di/Teribe Broram in Costa Rica, and the Maijuna and Kichwa del Río Napo in Perú.