Vocalizations and behaviour of Pacific humpback dolphins Sousa chinensis

Citation
Sm. Van Parijs et Pj. Corkeron, Vocalizations and behaviour of Pacific humpback dolphins Sousa chinensis, ETHOLOGY, 107(8), 2001, pp. 701-716
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ETHOLOGY
ISSN journal
0179-1613 → ACNP
Volume
107
Issue
8
Year of publication
2001
Pages
701 - 716
Database
ISI
SICI code
0179-1613(200108)107:8<701:VABOPH>2.0.ZU;2-7
Abstract
Very little is known about the acoustic repertoire of the Pacific humpback dolphin Sousa chinensis. This study, off eastern Australia, used concurrent observations of surface behaviour and acoustic recordings to gain an insig ht into the behavioural significance of humpback dolphin vocalizations. Hum pback dolphins exhibit five different vocalization categories: broad band c licks; barks; quacks; grunts; and whistles. Broad band clicks were high in frequency (8 kHz to > 22 kHz), were directly related to foraging behaviour and may play a role in social behaviour. Barks and quacks were burst pulse sounds (frequency: 0.6 kHz to > 22 kHz, duration: 0.1-8 s) and were associa ted with both foraging and social behaviour. The grunt vocalization is a lo w frequency narrow band sound (frequency 0.5-2.6 kHz, duration 0.06-2 s) an d was only heard during socializing. There were 17 different types of whist les, ranging widely in frequency (0.9-22 kHz) and vocal structure (n = 329) . The predominant whistle types used by the groups were type 1 (46%) and ty pe 2 (17%). Most whistles were heard during both socializing and foraging. The number of whistles recorded in a group increased significantly as the n umber of mother-calf pairs increased, suggesting that whistles may be used as contact calls. Few vocalizations were heard during either travelling or milling behaviours. Broad band clicks, barks and whistle type 1 were the on ly vocalizations recorded during either travelling or milling.