RESEARCH INTERESTS

My research interests include the evolution of social and reproductive behaviors. I am particularly interested in the evolution of aggressive behavior, and mechanisms and evolutionary significance of mate choice. My dissertation research on the reproductive behavior of Neotropical cichlid fishes, and the large and growing body of research on cichlid behavior, has clearly demonstrated the usefulness of this behavioral system in addressing many current questions in behavioral biology. These include questions about territoriality and aggression, mate choice and sexual selection, the evolution of parental care, particularly biparental care, as well as the neurophysiological bases of behavior, particularly the role of visual mechanisms in the evolution of behavior.

Several questions developed during my research at Indiana University, and in my own lab at Slippery Rock University, are currently being investigated. These include:

1. How do mate choice and size assortative mating occur in cichlid fishes?
My previous work using ethological dummies revealed the ability of cichlid fishes to assess the size of conspecifics relative to their own (Beeching 1992). This mechanism may explain the size assortative pairing typical of these fishes. Dummy presentation experiments have, until now, been inconclusive due to the paucity of courtship behaviors elicited by stationary dummies. Newer techniques utilizing a carousel apparatus, which adds the component of motion to fish dummies, have been successful in eliciting courtship behavior in controlled experiments with other species currently being studied in our laboratory. Further, experiments utilizing a paired dummy presentation paradigm are currently being developed (Beeching 1995), as well as mate choice experiments using live fishes (Beeching et al. 1998, Beeching and Hopp 1999).

2. How does the caudal eye-spot (ocellus) function in intra-specific interactions?
While interest in the evolution of color patterns seems to be renewed, most studies of caudal ocelli in fishes continue to conclude that these color patterns function in predator deterrence. Experiments with the oscar have demonstrated that the ocellus functions as a signal during social interactions (Beeching 1993), yet the social significance of this signal remains unclear. By manipulating the color pattern of dummy cichlids, as well as live fish, I hope to determine the social significance of this color pattern.

3. What is the strategy employed by oscars in territorial contests characterized by body size asymmetries?
Previous experiments confirmed the hypothesis that territorial oscars assess body size asymmetries visually, and exhibit highest aggression toward opponents approximately 20% than themselves. This finding conflicts with the predictions of game theory models, which predict maximum aggression should occur when opponents are of equal size. Do the results of the dummy presentation experiments represent another strategy being used by oscars?

4. How do aggressive and courtship motivations and behavior result in successful pair formation in sexually monomorphic cichlid species?
This is, in some sense, the most persistent question in my research, and one that has been pursued by researchers since the 1930s. I don't think the answer lies in the traditionally examined realm of simple, sexually dimorphic coloration, olfactory cues, behavioral stereotypy, or auditory cues. All have been investigated. Instead, the process may be essentially dynamic, and its "local unpredictability" an inherent component of the dynamic interactions between the sexes. I would like to know the basics of the decision rules that yield this unstable behavioral system.

5. What is the ontogeny of color patterns in Neotropical cichlids?
Several students and I have recently begun a study of chromatophore expression in juvenile convict cichlids, in an effort to learn how these behaviorally significant color patterns arise developmentally. As a first step, we've begun by assembling a complete microphotographic record of color pattern development through 3 months developmental age.

6. Ethology and Behavioral Ecology of Atlantic Bottlenose Dolphins (Tursiops truncatus)
An important component of the Dolphin Research Project is the observation, recording and analysis of wild dolphin behavior in the Wallops Island area. Specifically, the Dolphin Research Project is currently addressing these questions:

• How do oceanic and atmospheric conditions affect dolphin activity in the Wallops Island area?
• How does group size and composition affect dolphin social and feeding behavior?
• What are the fundamental "action patterns" or activities performed within our local dolphin groups?