Research

The enlarged structures, bright colors, and dynamic movements seen across animals fascinate researchers and the public alike. We can understand the evolution of these traits by integrating animal behavior, biomechanics, and physiology. I’m interested in questions that span these fields, toward the goal of understanding how and why animals look and act the ways they do. I'm also broadly interested in topics across animal behavior, ecology and evolution, including animal perception and the evolution of signals and communication systems.


Contest resolution

I study contest resolution in the mantis shrimp Neogonodactylus bredini, which compete over access to territories in coral rubble. During contests, N. bredini exchange visual displays and high-force strikes using their spring-powered raptorial appendages. These strikes are some of the fastest movements in the animal kingdom, able to crack open snails and dismember crabs. How do competitors use these weapons to resolve contests without killing each other?

In the first chapter of my dissertation, I showed that N. bredini resolve body length-matched contests by ritualistically exchanging strikes on each other's tailplates (telsons). Competitors escalated to this "telson sparring" in 33/34 contests, while they presented visual displays in only 17/34 contests. Contest winners did not have greater peak strike force than losers; instead, winners struck a greater number of times during contests. By studying both behavior and biomechanics, I showed that N. bredini use their deadly weapons to resolve contests without injury. This work was published in 2015 in Biology Letters. Find out more on the publications page.

Theoretical models of contest resolution describe the rules animals follow to resolve contests. When and how do animals decide to give up? To answer these questions, I've matched N. bredini contest dynamics to theoretical models. I’ve tested these models at both the level of the contest (how long do contests last?) using correlation analysis, and at the level of contest behaviors (how do behaviors themselves progress through contests?) using sequential behavioral analysis and network analysis.


The energetics of telson sparring

I’ve shown that telson sparring – the ritualized exchange of strikes on the telson - is common across matnis shrimp contests. While I’m asking how sparring fits into broader trends of resolution behavior (above), I’m also interested in the biomechanics and energetics of telson sparring. Mantis shrimp strikes move at bullet-like accelerations – how do they deliver and withstand these blows during a contest?

I use high-speed video techniques to analyze the biomechanics of mantis shrimp telson sparring. I pair competitors in semi-natural contests, film their sparring strikes at 40,000 frames/second, and use R and MatLab code to analyze strike kinematics and mechanics. I plan to use these data to answer fundamental questions about the biomechanics and energetics of sparring.


Other interests and collaborative projects

I'm also interested in general questions in animal behavior, including:

1. Sensory systems and perception in animal behavior. How do animals perceive their world, and how does this impact animal communication? (In collaboration with the Nowicki Lab at Duke). I'm currently working with the Nowicki Lab and Nick Brandley to write a review paper on the topic of categorical perception. In categorical perception, a continuous stimulus is perceived in discrete categories. For example, humans view color (a continuous wavelength) as belonging to discrete groups (blue, yellow, etc...), and our perceptual transition between colors is step-like, not gradual. Categorical perception has been tested in some animals, but is underexplored and could have implications for our understanding of animal communication and the evolution of animal signals. I'm also currently testing if zebra finches categorize carotenoid-based coloration (an important signal in this system), working as a research assistant with the Nowicki Lab, Eleanor Caves , and Matthew Zipple.

I'm also currently investigating the use of the telson as a sensory structure in N. bredini, in collaboration with Rachel Cohn, a Duke undergrad. This project seeks to identify the sensory structures mantis shrimp might use to sense strikes received during telson sparring. Stay tuned!

2. Animal communication theory. Can diverse phenomena in animal communication be summarized by the costs and benefits to each player in the interaction? (Work in collaboration with Matthew Zipple and Eleanor Caves at Duke University).

3. Field studies. While lab conditions allow for greater control, observing animals in nature is critical to understanding animal behavior. I’ve conducted most of my dissertation in the field (in Panama) and have worked with other researchers on several projects, like collecting mantis shrimp in Florida and studying cleaner shrimps in Curacao and the Red Sea.