Lima, I.M.S., Andrade, L.G., Carvalho, R.R., Lailson-Brito Jr., J., and Azevedo, A.F. (2012). "Characteristics of whistles from rough-toothed
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 13.94 kHz. 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+236 ms and 89.7% of the whistles lasted <600 ms). Seventy-eight whistle
contour types were found in the total of whistles analyzed, and 27 (7.9%) of these occurred only
once. Most of the whistle types were unique to a particular recording session (N=43). The signals
emitted by the rough-toothed dolphins in southeastern Brazil were characterized by low frequency
modulation, short duration, low number of inflection points, and breaks. Differences in the mean
values of the whistle parameters were found between this and other studies that recorded Steno
bredanensis, but as in other localities, whistles above 14 kHz are rare.
Best regards,
Isabela Lima