I am interested in the evolution behavioral interactions, especially in terms of communication, evolution, sensory systems, ecology, learning, cognition, and personality. In particular, I am interested in how these processes are influenced by evolutionary constraints, and how ecological factors may have shaped these abilities. To date, I have worked with lizards, reptiles, insects, fish, cuttlefish, and humans. Specifically, my past and current research interests have focused on:
Signal Design and the Evolution of communication systems and their constraints. Signals are designed to communicate effectively. My research has addressed communication on two levels: signal detection and signal recognition. Much of my research has focused on understanding the sensory exploitation theory of communication, which suggests that signals have become more salient through the influence and manipulation of sensory structures. First, I am interested in the evolution of the visual system, and how certain signals have been selected (i.e., natural vs. sexual selection) for successful communication. Secondly, I am interested in the ability of the visual system to partition relevant sensory information from irrelevant visual or ambient noise (i.e., the movement of background stimuli). Thirdly, by understanding motion perception in this species, I manipulated the primary aggressive and submissive signal characteristics using sophisticated 3D animation. Lastly, I manipulated the signal order (i.e., syntax) and structural morphology to investigate whether recognition was maintained through the motion characteristics despite the absence of morphological cues.
Evolution of mating systems. First, my colleague Dr. Greg Holwell (University of Auckland) and I are interested in understanding the evolution of morphological traits in mantid genitalia, and whether reproductive structures have evolved in isolation, or have been influenced by populations meeting at contact zones. Secondly, my colleague Dr. Daniel Warner (Iowa State University) and I are interested in the reproductive ecology of Jacky lizards and the success of individual survival (i.e., measured and predicted by the frequency of territorial displays to an opponent male in correlation to survival rates). Thirdly, during my post-doctoral candidature, Dr. Culum Brown (Macquarie University) and I examined the interaction between competing males for a single female in the morning cuttlefish (S. plangon) and the mate guarding behavior exhibited during exchanges. Fourthly, I plan to investigate sexual selection in fish using computer-generated animation.
Visual sensitivity to prey and predator models, and predator detection. First, visual systems have evolved to recognize the motion characteristics of friends or foes. Here, we compliment the isolation of motion characteristics in our 3D animation and aim to apply a motion algorithm to better understand the speed, acceleration, velocity, and direction of predator and prey motion. Secondly, prey must identify characteristics of predators in order to avoid death. It is clear that prey species are likely receiving multimodal cues from predators, but I am particularly interested in titrating the visual features from the chemical components, and then understanding the interaction between them. Our preliminary results with mummichogs (Fundulus heteroclitus) suggest that large groups aggregate in order to minimize the impact of predation, and smaller groups will adopt a fleeing strategy so that it is not likely that the predator will be able to capture all individuals.
Learning paradigms as tools for understanding sensory and cognitive ability. The ability to acquire information from the environment is complex. Previously, I used an instrumental conditioning procedure to understand flicker-fusion sensitivity, first in the tuatara (Sphenodon punctatus). More recently, my research with Jacky lizards employed an instrumental paradigm in order to assess visual ability. Lizards were required to select a directional motion pattern, which mirrored the same direction as the moving dots. Upon making this selection, they were rewarded with both a second-order reinforcer (computer-generated invertebrate) and a primary reinforcer (mealworm).
Social learning and social facilitation. The ability to transmit and acquire information from conspecifics is a valuable survival strategy. In conjunction with my colleagues at Macquarie University, I conducted a series of experiments examining the social transmission of discrimination training in mourning cuttlefish (S. plangon). In addition, I examined social transmission of schooling information small baitfish, mummichogs (F. heteroclitus). With my previous undergraduate student, Morgan Mingle, at Southwestern University, we develop a 3D animation of a mummichog, and plan to manipulate the model to be perceived as though it is feeding from a favorable location. We can also examine the whether the risk of feeding in a profitable location, as indicated by the model, outweighs the possibility of predation in the presence of a natural predator.
Personality and behavioral syndromes. The focus of personality and behavioral syndromes in animal models is a relatively new area that is generating much interest. Along with my colleagues at Southwestern University and Macquarie University, I am particularly interested in examining whether cuttlefish exhibit bold/shy behaviors when presented with familiar and unfamiliar conspecifics, prey, and predators. Sexual selection theory suggests that individuals that exhibit stables traits over time have been sexually selected as a consequence of more favorable traits. More recently, I have begun investigating this phenomenon in mummichogs. I am particularly interested in whether the schooling behavior of individuals is affected by group size, and whether the cost-benefit ratio of schooling more boldly or shyly might be a more cooperative strategy for survival, as opposed to exhibiting individual traits to improve reproductive success. In the context of social learning, I am also interested in whether bold/shy individuals are better demonstrators or observers. Series of experiments is scheduled to begin in conjunction with my colleagues at Southwestern University, Université du Québec à Montréal, and Macquarie University.
Sensory physiology. Visual is a critical and dominant sensory modality in many organisms. The absence of visual characteristics impairs the ability of conspecifics to communicate effectively. My interest in lizard, fish, and cuttlefish have broadly examined the visual sensory ability in these species and their ability to discriminate motion, morphology, texture, and motor patterns. Subtle differences between these features may be conspicuous. However, it may require additional visual attributes to elicit recognition. I am interested in how interactions have been shaped by sexual and natural selection pressures (i.e., mating vs. avoiding predation) and constraints (i.e., environmental noise). The evolution of the visual systems has thus shaped physiological mechanisms.
Conservation and the Impacts of the Urban Environment. Rapid urbanization has modified local habitats. This process has disrupted ecological processes, displaced flora and fauna, engaged in habitat modification, allowed invasive species to colonize, and led to species decline. Here, we aim to better understand the effects of urbanization on local flora and fauna, and what can be done to protect and improve declining habitat.
PAST RESEARCH STUDENTS
Erin Dammann (B.S. Psychology – Southwestern University): Schooling behavior of mummichogs (Fundulus heteroclitus) and effects of predation on group size
Stephanie Henderson (B.S. Animal Behavior – Southwestern University): Schooling behavior of mummichogs (Fundulus heteroclitus) and effects of predation on group size
Shane Littleton (B.S. Psychology – Southwestern University): Schooling behavior of mummichogs (Fundulus heteroclitus) and effects of predation on group size
Morgan Mingle (B.S. Animal Behavior – Southwestern University): Development of mummichog (Fundulus heteroclitus) 3D animation to examine social learning and social facilitation
Gemma White (BSc. Marine Biology – Macquarie University): Personality traits in the mourning cuttlefish (Sepia plangon)