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 vasot ocin (AVT), on the calling behavior of male Acris crepitans during and imme diately following a simulated acoustic agonistic encounter. AVT did not blo ck the aggressive response to agonistic calls, as the changes in temporal c all characteristics in response to the encounter were similar to those of s aline-treated males. However, AVT caused males to begin calling sooner duri ng the agonistic encounter and to call significantly more than saline males during and after the agonistic encounter. In addition, AVT-treated males m aintained 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 w ere more likely to exhibit a rebound effect which resulted in larger change s in calling parameters compared to AVT-treated animals. The results indica te that AVT causes changes in calling behavior in male A. crepitans during and following an agonistic encounter that are consistent with animals highl y motivated to maintain vigorous active calling throughout changing social conditions. (C) 1998 Academic Press.