Acoustic Parameters of Guiana Dolphin (Sotalia guianensis) whistles in the Southern Gulf of Venezuela

Abstract

The Guiana dolphin, Sotalia guianensis, is widely distributed along the coasts of Central and South America. Similar to other delphinids, this species emits echolocation clicks, burst pulses, and whistles. Although whistling seems to play a major role in the social organisation of dolphins, there is a lack of knowledge about Guiana dolphin whistles outside of populations in Brazil and Costa Rica. In this study, we describe the acoustic structure of Guiana dolphin whistles from the southern Gulf of Venezuela for the first time. We recorded the whistles using an omnidirectional hydrophone (CR1). For each whistle, we measured maximum frequency (kHz), minimum frequency (kHz), starting frequency (kHz), ending frequency (kHz), duration (s), and number of inflection points, using spectrograms created in SpectraLAB 4.32 software (v. 17). Whistles presented an average starting frequency of 10.58 kHz (SD=2.49 kHz), a mean ending frequency of 13.96 kHz (SD=2.60 kHz), an average minimum frequency of 10.31 kHz (SD=2.33 kHz), a mean maximum frequency of 13.96 kHz (SD=2.51 kHz), an average duration of 0.27 s (SD=0.14 s), and a maximum of 4 inflection points (mode 0). This research provides new insights into the acoustic behaviour of the Guiana dolphin in the Gulf of Venezuela.

Key Words:  Guiana dolphin, Sotalia guianensis, acoustic structure, acoustic parameters, Gulf of Venezuela, cetacean

Citation: Barrios-Garrido, H., De Turris-Morales, K., Delgado-Ortega, G., Nash, C.M., Espinoza-Rodríguez, N. 2016. Acoustic Parameters of Guiana Dolphin (Sotalia guianensis) whistles in the Southern Gulf of Venezuela. Aquatic Mammals, 42(2): 127-136, doi: 10.1578/AM.42.2.2016.127