Behavioral variation in natural contests: integrating plasticity and personality

Animals often interact aggressively when competing over limited resources. Aggressive decisions can be complex, and may result from multiple sources of behavioral variation. The outcome of contests may be explained through contest theory and personality, by considering conjointly plasticity and individual consistency. This integrative approach also allows investigating individual differences in responsiveness to environmental changes. Here we observed multiple agonistic interactions occurring among eastern chipmunks (Tamias striatus) competing for food resources supplied at different distances from their burrows. Using an individual reaction norm approach, we found that the probability of winning a contest depended on an individual’s own intrinsic characteristics (mass, age, but not sex) but was also adjusted to characteristics of its opponents. Winning a contest also depended on extrinsic environmental characteristics such as distance to the contestants’ burrows, but not the order of a...