ABSTRACT

Observed variations in dolphin acoustic signals may be associated with behavior, social composition, and local differences in habitat features. This study aims at characterizing whistles emitted by the spinner dolphin population occurring in the waters of the main island of the Archipelago of Comoros (Mozambique Channel, Indian Ocean) and to assess factors possibly influencing the acoustic structure of signals. All parameters examined on 953 whistles significantly differed in relation to environmental conditions, group size, and behavior. By mixed model analysis, it was found that only habitat characteristics play a role in the variation of frequency parameters, and exerted on the acoustic structure of whistles stronger influence than socio-behavioral factors. Spinner dolphins occurring in the Comoros archipelago use higher frequencies and show longer signal duration compared to those from the Pacific and the Atlantic. Results suggest that frequency parameters are distinctive of the local population and reflect the habitat use of the species in the area. In conclusion, acoustic measurements may be crucial elements to be included in monitoring programs to identify local peculiarities of dolphins’ populations.

Best regards

Marco Bonato

"... un viaggio puo' durare tre giorni, ma raccontare una vita intera..."

" ... a voyage could be only three days long , but talk about all life ..."

"... un voyage peut prendre trois jours, mais raconter une vie entière ..."

- PhD Student on Biology at Torino University

Department of Life Science and Systems Biology

V. Accademia Albertina 13, 10125 Torino - Italy

- Biologist at L.A.S.A. (Lab of Analysis of Environmental System)

D.I.I. (Dipartimento Ingegneria Industriale) Padova University

Via Marzolo 9, 35131 Padova - Italy

LASA on web: http://147.162.77.55/