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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]

Anurans have long been a model system for studies of animal communication, but little is known about how individuals acquire acoustically linked mating behaviors. The manner in which behaviors are acquired may be a source of variation in these behaviors. In this study, we reared Physalaemus pustulosus in four acoustic treatment groups: hearing a conspecific chorus of P. pustulosus frogs, acoustically isolated from all frog calls, hearing a chorus of the congener P. enesefae, and hearing noise. We then measured the spectral and temporal characteristics of the calls produced by males and tested them for differences between treatment groups. Males reared in isolation produced calls that were shorter in duration. Females showed discrimination against these shorter calls. Early experience can alter the advertisement call of male P. pustulosus, and acoustic isolation leads to the acquisition of calls that are less attractive to females. Males reared in other groups produced species-typical calls. The calls of male P. pustulosus may be the product of a gene by environment interaction. [ABSTRACT FROM AUTHOR]