My findings on social signals emission also suggest that burst pulses vocalizations probably play an equally important social signaling role as do tonal sounds. Moreover, the fact that was observed a positive relation between group size and the production of social signals, confirms that dolphin vocalizations are used for communicative and social purposes. The results, showing that vocal emission increased, especially in those activities involving excited depredation or socializing, confirmed that activity and social signals production were related. Bottlenose dolphin communication sounds ranged from soft and melodic sounds to harder, almost harsh sounds. The acoustic repertoire observed in this study was extremely diverse.

Over the 4-year study period, 25 months were spent in the field and the dataset consisted of 35 hours of dolphin observations and simultaneous recordings. Data were collected as part of a long term study, in which acoustic recording and behavioral observations (from surface and underwater) were made.

This study carried out year round from 2005 to 2008 represents the first attempt in the Mediterranean basin to outline the repertoire, production rates of social sounds, and associated behavior of Mediterranean bottlenose dolphins. Bottlenose dolphins are an extremely vocal mammalian species and vocal communication plays an important role in mediating social interactions.

Common bottlenose dolphin