Raíssa Furtado, Sabrina P. Santos, Tailise M. Dias, Rogério P. Bastos, Fausto Nomura
South American Journal of Herpetology 11 (2), 136-147, (1 August 2016) https://doi.org/10.2994/SAJH-D-16-00002.1
KEYWORDS: acoustic communication, Advertisement call, Air temperature, Complex call, Territorial call, vocalization
Communication in anurans is mostly mediated by acoustic signals. Depending on the type of social interactions, different call types can be displayed by anurans. The main function of advertisement calls is to attract females, which prefer males whose advertisement calls have high repetition rates. Conversely, territorial calls are used to defend territories. We described the advertisement and territorial calls of Bokermannohyla sapiranga (n = 25 individuals), Hypsiboas albopunctatus (n = 21 individuals) and H. goianus (n = 57 individuals) from the Silvânia National Forest, Cerrado. We tested the hypothesis that advertisement and territorial calls are emitted under different social contexts and are, therefore, structurally distinct. We also assessed the influence of air temperature on call rates. We made recordings during reproductive (spontaneous formation of chorus) and aggressive (presence of intruder male) contexts. To simulate the presence of potential rivals we exposed males to acoustic (audio playbacks) and/or visual (artificial models) signals. We analyzed the following call parameters: repetition rate, call duration, number of notes and/or pulses per call, note and/or pulse duration, inter-note and/or inter-pulse interval, frequency range (min-max), and dominant frequency. Here we describe for the first time the territorial call of B. sapiranga, the compound territorial call of H. albopunctatus, and the compound short territorial call, simple and compound long territorial calls, and simple and compound complex calls of H. goianus. Advertisement calls were the most frequently emitted vocalizations. The advertisement call of B. sapiranga, the advertisement and territorial notes of H. albopunctatus, and the simple short territorial call of H. goianus were positively correlated with air temperature. However, the call rates did not differ between social contexts in B. sapiranga and H. albopunctatus. In H. goianus, advertisement and complex calls were emitted more frequently during reproductive interactions, whereas compound long territorial calls were emitted only during aggressive interactions. Our results indicate that considerable sampling effort under different contexts is required to study the vocal repertoire of anurans more precisely. Therefore, the present study is a starting point for experimental studies to elucidate the function of these complex acoustic signals during social interactions.