Diversidade acústica do boto-cinza Sotalia guianensis, (Van Bénédén, 1864) na Baia de Todos os Santos – Bahia

Abstract

Communication is a process carried out by various species of animals, being fundamental for the development of vital activities for organisms, such as group cohesion, reproduction, feeding. The studies on the bioacoustics of the gray dolphin report that there are two beeps, which are divided into tonal sounds, known as whistles and pulsed sounds, such as echolocation clicks and explosive pulses, which are screams and gargling. After characterization of the sound repertoire, many studies were developed focusing on whistling emissions, leading to a lack in studies of other sound classes. This research was carried out in Todos os Santos Bay, in the state of Bahia, aboard a sailboat. The sounds were recorded using a hydrophone and a 48 kHz frequency response recorder. Recordings were performed at three times, in the presence of dolphins, in the presence of boats and in the absence of dolphins and boats, afterwards, the data were analyzed using the Raven Pro 1.5 software. The present study identified that the acoustic repertoire of the species in the Todos Os Santos Bay is similar to the description of the sounds of other dolphin populations in the Brazilian coast, being composed by whistles, echolocation clicks and screams. Clicks and whistles were the most abundant emissions in the study area. In due course it was also possible to observe that the traffic of vessels does not interrupt the vocalizations of the species.