Identifying interaction epochs in social behavior: contest phases in pairwise zebrafish fights

Animals engage in pairwise fighting behavior to settle dominance disputes. As a model social behavior, fighting is of particular interest due to the strong interactions between individuals and the richness of the social tasks they are attempting to solve. Contests often contain discrete phases of escalating aggression, each of which contains a set of stereotyped dynamics. Fights start with non-physical displays, can proceed to physical attacks, and end with asymmetric dominance behaviors. Here we present our work in identifying these phases in adult zebrafish fights on multiple timescales. We track fish bodypoints in 3D and identify the three main phases of the contest. Within the physical attack phase, we uncover short-time multi-animal behavioral motifs that the fish use to establish dominance.