Evoked Vocal Responses Change with Experience in Male Physalaemus pustulosus.

The acquisition of signals used in intrasexual communication is not well studied. To better understand the possible contribution of early experience to the acquisition of intrasexual responses, we reared Neotropical Tungara frogs, Physalaemus pustulosus, in four acoustic environments: 1) conspecific chorus, 2) heterospecific chorus, 3) acoustic isolation, and 4) noise. For the heterospecific chorus, we chose the calls of a congener, P. enesefae, with which P. pustulosus is sympatric in parts of its distribution. We measured the evoked vocal responses (EVR) of these frogs in response to calls of the conspecifics, to calls of the congener, and to calls representing an intermediate between the two species. Male P. pustulosus reared hearing the calls of P. enesefae produced more calls overall and more complex calls in response to the call of P. enesefae. This is consistent with the hypothesis that the EVR of male anurans can be influenced by early experience and is the product of an interaction between genes and the environment. [ABSTRACT FROM AUTHOR]