Temporal patterning differences in contact calls among odontocetes’ species

Abstract

Contact calls in odontocetes (toothed whales) have information of individual identity or group identity. Sound types used for contact calls, however, differ among species. Signature whistles in bottlenose dolphins, which are thought to function as “names” in human, are tonal sounds, whereas PS1 calls in beluga whales are pulsed sounds. Both signature whistles and PS1 calls have usually exchange pattern that calls are followed by calls by other individuals within around 1 second. Dolphins tend to produce next call when no individuals call back. Contact calls are usually produced repeatedly in a bout. Moreover, signature whistles often include multiple loops, sometimes with breaks between loops. The duration of breaks between loops is different between bottlenose dolphins and Indo-Pacific bottlenose dolphins. These results suggest that temporal patterning in contact calls in odontocetes is important for species identity.