TY - JOUR T1 - Description and classification of Indian Ocean humpback dolphin ( Sousa plumbea ) whistles recorded off the Sindhudurg coast of Maharashtra, India JF - Marine Mammal Science Y1 - 2018 A1 - Bopardikar, Isha A1 - Sutaria, Dipani A1 - Sule, Mihir A1 - Jog, Ketki A1 - Patankar, Vardhan A1 - Klinck, Holger KW - humpback dolphin KW - India KW - passive acoustic monitoring KW - Sousa plumbea KW - whistles AB -

The Indian Ocean humpback dolphin (Sousa plumbea), a common cetacean species in India, has a diverse vocal repertoire, which to date has not been described in detail. This study focused on analyzing their whistle vocalizations. Humpback dolphins were recorded off the Sindhudurg coast of Maharashtra, India, and 2,260 whistles were analyzed for their acoustic characteristics. Whistles spanned a wide frequency range between 2.3 kHz and 33.0 kHz, with durations ranging from 0.01 s to 1.60 s. Whistles were categorized into seven contour classes based on their qualitative prop- erties. A classification and regression tree (CART) analysis was used to quantify vari- ability between the seven contour classes using the measured acoustic features. Based on the CART analysis, frequency gradient, minimum slope, maximum slope, begin- ning and ending slope accounted for most variability between whistle types. CART resulted in an overall classification accuracy of 89.5%. This study provides a detailed description of acoustic features and qualitative properties of humpback dolphin whis- tles from the northwestern coast of India. Further comparisons of acoustic data from Sousa populations along the Indian coast are necessary to determine possible geo- graphic variations in whistle characteristics and whether the variations are driven by environmental or genetic factors or a combination of both.

VL - 34 UR - http://doi.wiley.com/10.1111/mms.v34.3 IS - 3 JO - Mar Mam Sci ER -