In the early 1900’s, Jakob von Uexküll used the term “umwelt” to describe the perceptual world in which an organism exists and acts. Since then, advances have been made in both sensory physiology (the physiological basis of sensory systems) and receiver psychology (the behaviors that result from sensory input). One challenge we face, however, is that sensory physiology does not directly predict an animal’s umwelt, so we are left with an incomplete understanding of how physiology influences the umwelt, the role of the umwelt in behavior, and whether constraints result in similar umwelten across species. In the Caves lab, we investigate visual perception in animals by studying links between signaling behavior and signal form, sensory physiology, perceptual processing, and behavioral outcomes across species. Our broader aim is to better our understanding of how signals and perceptual systems evolve, and in particular how and when differences in sensory capability lead to differences in perception that influence resultant behaviors. Thus, we take an interdisciplinary approach by conducting research projects that focus on different stages of sensory and perceptual processing that occur between when a sender emits a signal and when a receiver responds, including signaling behavior, signal filtering by the environment and the visual system, perceptual processing, and behavioral outcomes.

Our current research focuses on three large areas:

1. The Behavioral Ecology of Cleaning Interactions

Cleaning interactions, in which a small ‘cleaner’ organism removes and often consumes material from a larger ‘client,’ are some of the most enigmatic and intriguing of interspecies interactions. Studies of cleaning interactions have primarily focused on marine systems, where cleaners are small fishes or shrimp that live at “cleaning stations” and remove material such as ectoparasites from clients, which are usually larger fish. However, cleaning is widespread both taxonomically and geographically--organisms as diverse as crustaceans, insects, birds, fishes, mammals, and reptiles can all serve as cleaners, while cephalopods, reptiles, mammals, and fish have been recorded acting as clients. 

Research in the Caves lab focuses primarily on cleaner shrimp and client fish, but we also study other cleaning systems (such as mongooses that clean warthogs in Uganda's Queen Elizabeth National Park). We are particularly interested in understanding:

• the behavioral and ecological dynamics of cleaning interactions
• how cleaners and clients learn mutualistic behaviors
• how the outcome of an individual cleaning interaction depends on the ecological, behavioral, and social context. 

2. Vision and Signaling in Interspecific Interactions

Animal visual capabilities differ significantly from our own, so in studies of visual signals and visually guided behaviors, we must account for the appropriate receiver’s visual capabilities. Much of our research applies measures of receiver visual capabilities to studies of signaling. We focus in particular on interspecific interactions, in which the two parties may have very different visual capabilities. Most of our work in this area involves cleaning interactions, an interspecies interaction in which small “cleaner” organisms remove and usually consume material from a larger “client.” In the case of cleaner shrimp, our primary study system, many clients are large fish that have the potential to be predators; despite this, cleaners are rarely consumed. Our research in this area focuses on asking such questions as:

• How do partners in interspecies interactions perceive and recognize one another? How do cleaners and clients use signals to mediate cleaning interactions?
• How do sensory capabilities and signals co-evolve? How have client fish viewers placed selection on cleaner shrimp signals?
• How do cleaning interactions (and interspecies signaling interactions more broadly) arise and remain stable over time? What information about cleaners do clients glean from signals, and how does that information stay honest and reliable?

3. Visual Capability and Perceptual Processing

Animals assess one another using signals in a range of contexts that are critically important for survival and reproduction, from mate choice to agonistic encounters. Two key factors that influence the receiver’s interpretation of visual stimuli are the physiology of the sensory system, as well as perceptual processes that occur after a stimulus is transduced by a sensory organ. Our research in this area uses a variety of techniques to quantify animal visual capabilities, and behavioral assays to examine how animals respond to variation in signal form and information. In particular, we focus on visual acuity, the ability to perceive spatial detail. Acuity is an understudied yet ecologically and behaviorally important aspect of visual capability, as it dictates what details an animal can or cannot resolve in a given scene. It is also extremely variable across species, spanning at least four orders of magnitude in animals with image-forming eyes. Our research on visual acuity focuses on describing cross-species variation in acuity, exploring the ecological and morphological factors underlying that diversity, using behavioral assays to integrate measures of acuity with studies of signaling.

ACTIVE

NSF IOS Behavioral Systems Standard Grant: Cooperation in Context: Biotic and abiotic drivers of interaction outcome in cleaner shrimp - client fish mutualisms.August 1 2024-July 31 2027. $856, 462 total to PI Caves

George A. Bartholomew Early Career Award, Society for Integrative and Comparative Biology, 2024

Jasper Loftus-Hills Young Investigator Award, American Society of Naturalists, 2019

Dorothy Skinner Award for Research Excellence, Society for Integrative and Comparative Biology, 2019

University Scholars Fellowship, Duke University, 2013-2018

James B. Duke Fellowship, Duke University, 2013-2017

Dean’s Award for Excellence in Mentoring, Duke University, 2017

National Geographic Young Explorer, 2016

National Defense Science and Engineering Graduate Fellow, 2013-2016

Downing Fellowship for Study at the University of Cambridge, Downing College, Cambridge, 2011-2012

Barry M. Goldwater Scholar, United States Congress, 2010-2011

Ecology and Evolutionary Biology