Quantifying Behavior and Interaction in Paired Fruit Flies*

Social behaviors are exhibited by a wide range of animals, and may be crucial not only to a specific animal’s survival, but the success of the species. These interactions vary across time scales, lengths scales, and sensory modalities, and are often difficult to characterize due to this complexity, in addition to problems posed by visual occlusion during interaction. We have recently introduced an unsupervised method for quantifying behaviors in pairs of interacting flies, and describe several interesting features of interaction that emerge in wild type Drosophila melanogaster. We find that behavioral densities between a given pairing exhibit distance-dependence, and mutual information reveals that interactions are enriched for similar simultaneous behaviors, regardless of pairing. Finally, we explore courtship bouts in opposite-sex pairings and show that prior to copulation attempts, females in successful and unsuccessful pairings display different behavioral phenotypes.