Vocal behavior and conspecific call response in Scinax Centralis (Anura, Hylidae)

Abstract

We describe the vocal repertoire of Scinax centralis (Anura, Hylidae), examine the influence of individual characteristics on acoustic parameters, and explore the role of sound level in aggressive interactions. Observations were carried out between January 1997 and June 2001 in a rivulet at Floresta Nacional (Flona), municipality of Silvânia, state of Goiás, Brazil. Male S. centralis emitted four distinct types of vocalizations: an advertisement call, two types of aggressive call and a displacement call. Early in the nightly vocalizing activity, males emitted more aggressive calls and few advertisement calls. Males called at faster rates when inter-male distances were shorter. The mean intensities of the three calls (advertisement call, long and short aggressive calls) were positively correlated with the number of individuals present in the chorus, as well as snout–vent ength (SVL) and mass of the calling male. The mean dominant frequency was negatively correlated with SVL and mass. Males increased the number of advertisement or aggressive calls during playback compared to pre-playback periods. Mean call intensity significantly increased with playback SPL. Like other species, Scinax centralis presents a complex vocal repertoire, with males emitting four types of vocalizations depending on social interactions.