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). Historically, most studies have made assumptions about what non-human animals can perceive based solely on sensory system physiology. 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 non-human animal perceptual experiences. In the Caves lab, we take an integrative approach to 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 animals perceive one another during crucial communicative interactions, for example during mate choice and cooperation.

Our current research focuses on three large areas:

1. The Behavioral and Sensory Ecology of Cleaning Interactions

An astonishing example of cooperative relationship occurs when a cleaner shrimp ("cleaner") removes an eats parasites from coral reef fish, which we call "clients." Intriguingly, many of the species of fish that cleaner shrimp service are predatory fish that can and regularly do eat crustaceans, which raises the question: why doesn't the client eat the cleaner? We seek to understand the behavioral ecology of these interactions (for example, how they vary with variation in the biotic or abiotic context), and the sensory ecology that allows them to occur (how do cleaners and clients recognize one another, or communicate to one another that they are partners rather than, respectively, a food item and a predator?). Leveraging the tractability of cleaners and clients for study in both field and lab, our upcoming projects will explore links between perception, partner recognition, and cooperation over scales ranging from the individual (What aspects of interspecies cooperation are learned or innate? Do perception and recognition change over a lifespan?) to the ecological (Does variation in the biotic or abiotic context alter perception, and thus partner recognition and cooperative decisions?) to the evolutionary (How does perception compare across species? How do the mechanisms of partner recognition evolve under selection from partner sensory systems?).

 

2. The Relationship Between Visual Capability and Visual Signaling

Animal visual capabilities differ significantly from our own, so when we study how animals use vision to communicate (for example by displaying a color patch or showing off a magnificent feather train), we must account for the appropriate receiver’s visual capabilities. Much of our research attempts to apply measures of receiver visual capabilities to studies of signaling, when animals use structures or behaviors to communicate with one another. I am particularly interested in variation in spatial vision (visual acuity) capability across the animal kingdom, since most animals do not perceive the same level of spatial detail as do humans. 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.

3. 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 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, I am interested in perceptual processes by which animals cannot perceive, or do not attend to, information that exists (and that we as human researchers can measure). For example, in categorical perception, although continuous variation in a stimulus exists, a viewer perceives only category designations.

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