Exploring aggressive interactions in the stalk-eyed fly, Teleopsis dalmanni

Understanding the mechanisms and determinants of conflict resolution is of great theoretical and practical importance because the outcome of contests between males over limited resources such as mates, territories, and food has profound fitness consequences. Stalk-eyed flies of the dimorphic species Teleopsis dalmanni provide the ideal model system to investigate conflict resolution because they engage in frequent and conspicuous bouts of aggression, using their exaggerated head morphology in a variety of complex signaling behaviors. Stalk-eyed flies engage in frequent fights over food resources, as well as over access to harems of females, with larger males typically prevailing when size disparities exist. However, specific behaviors associated with these fights have never been formally quantified. Behaviors during aggressive interactions were quantified using a sequential analysis program and frequencies of behaviors and behavioral transitions were examined in light of game theory modeling. Naive individuals were also tested in a series of size mis-matched and size matched interactions to test the importance of previous experience, which may manifest as winner or loser effects, in stalk-eyed flies.