The effects of arginine vasotocin on the calling behavior of male cricket frogs in changing social contexts.

We investigated the effects of the neurohypophysial peptide, arginine vasotocin (AVT), on the calling behavior of male Acris crepitans during and immediately following a simulated acoustic agonistic encounter. AVT did not block the aggressive response to agonistic calls, as the changes in temporal call characteristics in response to the encounter were similar to those of saline-treated males. However, AVT caused males to begin calling sooner during the agonistic encounter and to call significantly more than saline males during and after the agonistic encounter. In addition, AVT-treated males maintained a higher dominant frequency compared to saline animals during and following the agonistic encounter. Changes in temporal characteristics in the period following the agonistic encounter indicated that control males were more likely to exhibit a rebound effect which resulted in larger changes in calling parameters compared to AVT-treated animals. The results indicate that AVT causes changes in calling behavior in male A. crepitans during and following an agonistic encounter that are consistent with animals highly motivated to maintain vigorous active calling throughout changing social conditions.