Abstract: The bottlenose dolphin (Tursiops truncatus) has a highly variable acoustic repertoire of whistles, clicks, and pulse burst sounds. Whistles are used to express individuality (signature whistle) and emotional state, and to initiate and maintain contact within a group. This study investigated the whistle production pre- and post-partum of three female bottlenose dolphins and their calves at the Kolmården Djurpark, Sweden. Gestation lasts approximately 12 months, and with the approach of delivery, the behaviour of the female changed in several ways. Observations of the behaviour and sound production were done for up to seven months prior to birth and for up to the first 22 months of the calves’ lives. The results showed that whistle production increased significantly for all three females in the seven months pre-partum, with an accelerating increase in the days prior to birth. The whistles, therefore, might be used as an indicator that delivery is imminent. After birth, the mother-calf pair whistled more often when separated (66%) than when together (34%), and significantly more often when the calf returned to its mother than when she retrieved the calf.

Key Words: BOTTLENOSE DOLPHIN; TURSIOPS TRUNCATUS; WHISTLE PRODUCTION; PRE-PARTUM; POST-PARTUM; KOLMARDENS DJURPARK

Document Type: Research article

DOI: 10.1578/AM.31.2.2005.169

Page Numbers: 169 – 175