Bopardikar, Isha,Sutaria, Dipani,Sule, Mihir,Jog, Ketki,Patankar, Vardhan,Klinck, Holger
Description and classification of Indian Ocean humpback dolphin (Sousa plumbea) whistles recorded off the Sindhudurg coast of Maharashtra, India Journal Article
In: Marine Mammal Science, vol. 34, no. 3, pp. 755-776, 2018, ISSN: 1748-7692.
Abstract | Links | BibTeX | Tags: Arabian Sea, humpback dolphin, India, passive acoustic monitoring, sousa, Sousa plumbea, vocalization, Whistle, whistles
@article{,
title = {Description and classification of Indian Ocean humpback dolphin (Sousa plumbea) whistles recorded off the Sindhudurg coast of Maharashtra, India},
author = {Bopardikar, Isha,Sutaria, Dipani,Sule, Mihir,Jog, Ketki,Patankar, Vardhan,Klinck, Holger},
url = {http://dx.doi.org/10.1111/mms.12479},
issn = {1748-7692},
year = {2018},
date = {2018-01-01},
journal = {Marine Mammal Science},
volume = {34},
number = {3},
pages = {755-776},
abstract = {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 properties. A classification and regression tree (CART) analysis was used to quantify variability between the seven contour classes using the measured acoustic features. Based on the CART analysis, frequency gradient, minimum slope, maximum slope, beginning 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 whistles from the northwestern coast of India. Further comparisons of acoustic data from Sousa populations along the Indian coast are necessary to determine possible geographic variations in whistle characteristics and whether the variations are driven by environmental or genetic factors or a combination of both.},
keywords = {Arabian Sea, humpback dolphin, India, passive acoustic monitoring, sousa, Sousa plumbea, vocalization, Whistle, whistles},
pubstate = {published},
tppubtype = {article}
}
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 properties. A classification and regression tree (CART) analysis was used to quantify variability between the seven contour classes using the measured acoustic features. Based on the CART analysis, frequency gradient, minimum slope, maximum slope, beginning 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 whistles from the northwestern coast of India. Further comparisons of acoustic data from Sousa populations along the Indian coast are necessary to determine possible geographic variations in whistle characteristics and whether the variations are driven by environmental or genetic factors or a combination of both.
Madhusudhana, Shyam Kumar,Chakraborty, Bishwajit,Latha, G.
Humpback whale singing activity off the Goan coast in the Eastern Arabian Sea Journal Article
In: Bioacoustics, no. 147, pp. 1-16, 2018, ISBN: 0952-4622.
Abstract | Links | BibTeX | Tags: Arabian Sea, breeding, Goa, Humpback Whale, India, Megaptera novaeanglia, PAM, passive acoustic monitoring, song, vocal behaviour
@article{,
title = {Humpback whale singing activity off the Goan coast in the Eastern Arabian Sea},
author = {Madhusudhana, Shyam Kumar,Chakraborty, Bishwajit,Latha, G.},
url = {https://doi.org/10.1080/09524622.2018.1458248},
issn = {0952-4622},
year = {2018},
date = {2018-01-01},
journal = {Bioacoustics},
number = {147},
pages = {1-16},
publisher = {Taylor & Francis},
abstract = {AbstractFor over two decades, passive acoustic monitoring (PAM) methods have been successfully employed around the world for studying aquatic megafauna. PAM-driven studies in Indian waters have so far been relatively very scarce. Furthermore, cetacean populations inhabiting the north western Indian Ocean are far less studied than those in many other regions around the world. This work likely constitutes the first systematic study of the vocal repertoire of humpback whales (Megaptera novaeangliae) at a near-shore site along the western coast of India. Analysis of the observed vocalizations provides an insight into the behaviour of the species. This is significant as it assists in developing a better understanding of the habitat use of the non-migratory Arabian Sea humpback whale population. In contrast, other breeding populations such as those around the North Atlantic, South Pacific and Australia have been relatively well studied. Underwater passive acoustic data were collected during March 2017 using an autonomous logger at a shallow-water site off the eastern edge of Grande Island off the coast of Goa. Humpback whale vocalizations were found to occur over multiple days in the recordings. Time?frequency contours of individual units of vocalization were extracted with the aid of an automatic detection technique and the characteristics of the units were measured. Further, successive units were analysed for formation of phrases and themes. Reconstruction of putative songs from the identified units and themes was not possible due to the limitations imposed by the nature of data collection. Detailed analyses of units, phrases and themes are presented.},
keywords = {Arabian Sea, breeding, Goa, Humpback Whale, India, Megaptera novaeanglia, PAM, passive acoustic monitoring, song, vocal behaviour},
pubstate = {published},
tppubtype = {article}
}
AbstractFor over two decades, passive acoustic monitoring (PAM) methods have been successfully employed around the world for studying aquatic megafauna. PAM-driven studies in Indian waters have so far been relatively very scarce. Furthermore, cetacean populations inhabiting the north western Indian Ocean are far less studied than those in many other regions around the world. This work likely constitutes the first systematic study of the vocal repertoire of humpback whales (Megaptera novaeangliae) at a near-shore site along the western coast of India. Analysis of the observed vocalizations provides an insight into the behaviour of the species. This is significant as it assists in developing a better understanding of the habitat use of the non-migratory Arabian Sea humpback whale population. In contrast, other breeding populations such as those around the North Atlantic, South Pacific and Australia have been relatively well studied. Underwater passive acoustic data were collected during March 2017 using an autonomous logger at a shallow-water site off the eastern edge of Grande Island off the coast of Goa. Humpback whale vocalizations were found to occur over multiple days in the recordings. Time?frequency contours of individual units of vocalization were extracted with the aid of an automatic detection technique and the characteristics of the units were measured. Further, successive units were analysed for formation of phrases and themes. Reconstruction of putative songs from the identified units and themes was not possible due to the limitations imposed by the nature of data collection. Detailed analyses of units, phrases and themes are presented.