AcknowledgmentsWe are extremely grateful to Y Marescot for her

Anurans and insects communicating by means of acoustic signals have been widely used as model species to study the KU-57788 of sexual communication. This is because they use relatively simple acoustic signals that can be synthesized according to the parameters of the population distribution, a useful characteristic when exposed to controlled experimental procedures (Gerhardt and Huber, 2002 and Wells and Schwartz, 2006). Males of these taxa generally produce advertisement calls, a type of signal involved in female attraction and male spacing (Gerhardt and Huber, 2002 and Wells and Schwartz, 2006). The existence of positive 'KU-57788' phonotaxis in fertile females is well documented in a variety of species and has been commonly used as a proxy to study how intersexual selection may act on advertisement signals (e.g. Bentsen et?al., 2006, Gerhardt et?al., 2007 and Márquez and Bosch, 1997). Although males can be attracted by advertisement signals when searching for breeding sites (Lea, Dyson, & Halliday, 2002), in territorial species, maintaining other males at a distance is likely to occur, as syphilis may increase the possibility to defend important resources for reproduction. It is important to emphasize that the characteristics of advertisement calls may have an effect on the occurrence of physical contests between callers and potential intruder males (Bee and Gerhardt, 2001, H?dl et?al., 2004 and Reichert, 2010). In such cases, the dual function of advertisement signals provides the opportunity to determine how inter- and intrasexual selection interact on the same trait.