Characteristics of whistles from rough-toothed dolphins ( Steno bredanensis ) in Rio de Janeiro coast, southeastern Brazil

There is no information about the whistles of rough-toothed dolphins in the South Atlantic Ocean. This study characterizes the whistle structure of free-ranging rough-toothed dolphins recorded on the Rio de Janeiro coast, southeastern Brazil, and compares it to that of the same species in other regions. A total of 340 whistles were analyzed. Constant ( N =115; 33.8%) and ascending ( N =99; 29.1%) whistles were the most common contours. The whistles recorded had their fundamental frequencies between 2.24 and 13.94kHz. Whistles without inflection points were frequently emitted ( N =255; 75%). Some signals presented breaks or steps in their contour ( N =97; 28.5%). Whistle duration was short (347±236ms and 89.7% of the whistles lasted