Winner and loser effects and the development of dominance relationships inyoung coyotes: An integration of data and theory

Although it has been hypothesized that winner and loser effects may be impo rtant in the development of dominance hierarchies in diverse taxa, there ar e no studies of which we are aware that have investigated this idea for you ng mammals In this study, we analysed winner and loser effects during the d evelopment of dominance relationships in three litters of young coyotes (Ca nis latrans). We found clear winner and loser effects that were rank-relate d. Highest-ranking (alpha) coyotes showed winner effects, lowest-ranking (o mega) individuals showed loser effects, whereas there were no winner or los er effects for middle-ranking animals. We then modified Dugatkin's model fo r winner and loser effects and the structure of dominance hierarchies and f ound a high level of congruence between the empirical data and the predicti ons of the model. Indeed, theory predicted a relationship between winner an d loser effects and position in a hierarchy. We hope our results will serve as a heuristic for further comparative studies of these phenomena in diver se taxa.