Relationship between body size and release call parameters in Rhinella species (Anura: Bufonidae), with the description of the release call of Rhinella ocellata (Günther, 1858)

Abstract

A release call is a type of vocalisation emitted by anurans mainly to avoid either intra- or interspecific mating, during the breeding season. Due to the importance of these calls in the social context of anuran behaviour, we hypothesised that the release call parameters of Rhinella species should be associated with body size. We found a negative relationship between dominant frequency of the release calls and body size of Rhinella species. The release call of R. ocellata showed a harmonic structure composed of 1–4 pulsed notes and the call duration and dominant frequency had average lengths of 1.6 s and 1214 Hz, respectively. Acoustic signals can express information on the physical condition of their senders. Since release calls may reflect both phylogenetic relationships and individual or population differences, we emphasise the importance of describing and carrying out further studies on release calls.