Meeting Abstract

S6-2.4  Saturday, Jan. 5  Behavioral and physiological consequences of an audience in the group living cichlid, Astatotilapia burtoni DESJARDINS, J.K.; FERNALD, R.D.; Stanford University; Stanford University

In social animals, communication rarely involves only two animals. Rather individuals or groups of animals form an audience within range of the signaler and the receiver. Audience members can intercept signals to glean information. For example, by attending to aggressive encounters, audience members can determine the status, fighting ability and potential threat posed by others. In the cichlid fish, Astatotilapia burtoni, studied here, position in the dominance hierarchy depends critically on the social environment and animals must fight and risk injury to achieve dominance and consequent increased reproductive success. Prior work showed that A. burtoni males pay close attention to the behavior of others and store and interpret this information to minimize aggression. However, it is not known is whether A. burtoni males adjust their aggressive behavior in response to an audience. In addition, it is also unknown whether these bystanders show changes in physiology in response to witnessing aggressive interactions. By presenting males with an audience that varied in sex and size of its members, we found that varied the intensity of their aggressive encounters. We also found that circulating hormones and brain activity varied in bystander males, based on the nature of the aggressive encounter that they witnessed. Our results suggest that males attend to the presence and composition of an audience and adjust their behavior and physiology accordingly. By using social information, they may increase their chances of being reproductively successful while minimizing aggression from neighboring individuals.