Tree squirrels are known to communicate with their tails, but the only aspects of this communication that have been studied are tail flicking and piloerection. I investigated the communicative significance of tail position in wild eastern gray squirrels by videotaping them at an artificial food source. For each individual, I recorded dominance rank, aggression, avoidance behavior, and three variables describing tail position (tightness of curvature, portion of tail bent, and tail contact with ground). When a subordinate squirrel approached a dominant squirrel I recorded whether the approach was successful, and when a dominant squirrel approached a subordinate squirrel I recorded the distance that the subordinate moved away. All three tail position variables were correlated with the behavior of both the signaler and the receiver. The interaction effect between the tail positions of two interacting squirrels was a better predictor of the more dominant squirrel’s degree of aggression than either squirrel’s tail position alone. Analysis suggested that different tail variables do not communicate the same information, indicating that tail position may communicate multiple pieces of information simultaneously. I hypothesize that the tightness of the tail’s curvature communicates a squirrel’s degree of confidence (its status), the portion of the tail that is bent communicates degree of hunger, and whether the tail is touching the ground indicates intent to move
