Pre-and Post-Partum Whistle Production of a Bottlenose Dolphin (\u3ci\u3eTursiops truncatus\u3c/i\u3e) Social Group

The signature whistle of the Atlantic bottlenose dolphin (Tursiops truncatus) is a well-studied acoustic signal know for broadcasting identity and maintaining contact with conspecifics. Several studies have investigated the use of this signal surrounding the birth of calves to dolphin social groups, although there appears to be discrepancies between the findings of these studies. We aimed to add to the current literature in an attempt to reconcile some of these inconsistencies through investigation of signature whistle production by a bottlenose dolphin group two months prior to and two months following the birth of a calf to one of the social group members. We found that the production of signature whistles matching the contour belonging to our dolphin mother increased significantly in both the pre- and post-partum period. Heightened production of the mother’s signature whistle type in the first week of our focal calf’s life supports the establishment of a recognition system within this time period. Given that learning processes associated with the sound environment appear to begin shortly after calf birth, we also explored the signature whistle rates of the other social group members in an effort to determine whether any signature whistle production influenced the development of the dolphin calf’s own signature whistle type. We found that the signature whistles of the other social group members were significantly lower than production of the mother’s signature whistle until after the first week post-partum. None of the signature whistle types appeared to influence the signature whistle development of our focal calf within the scope of this study, however, as the calf did not develop a signature whistle in her first two months of life

Pre-and Post-Partum Whistle Production of a Bottlenose Dolphin (Tursiops truncatus) Social Group

The signature whistle of the Atlantic bottlenose dolphin ( Tursiops truncatus ) is a well-studied acoustic signal know for broadcasting identity and maintaining contact with conspecifics. Several studies have investigated the use of this signal surrounding the birth of calves to dolphin social groups, although there appears to be discrepancies between the findings of these studies. We aimed to add to the current literature in an attempt to reconcile some of these inconsistencies through investigation of signature whistle production by a bottlenose dolphin group two months prior to and two months following the birth of a calf to one of the social group members. We found that the production of signature whistles matching the contour belonging to our dolphin mother increased significantly in both the pre- and post-partum period. Heightened production of the mother’s signature whistle type in the first week of our focal calf’s life supports the establishment of a recognition system within this time period. Given that learning processes associated with the sound environment appear to begin shortly after calf birth, we also explored the signature whistle rates of the other social group members in an effort to determine whether any signature whistle production influenced the development of the dolphin calf’s own signature whistle type. We found that the signature whistles of the other social group members were significantly lower than production of the mother’s signature whistle until after the first week post-partum. None of the signature whistle types appeared to influence the signature whistle development of our focal calf within the scope of this study, however, as the calf did not develop a signature whistle in her first two months of life

Pre-and Post-Partum Whistle Production of a Bottlenose Dolphin (Tursiops truncatus) Social Group

The signature whistle of the Atlantic bottlenose dolphin (Tursiops truncatus) is a well-studied acoustic signal know for broadcasting identity and maintaining contact with conspecifics. Several studies have investigated the use of this signal surrounding the birth of calves to dolphin social groups, although there appears to be discrepancies between the findings of these studies. We aimed to add to the current literature in an attempt to reconcile some of these inconsistencies through investigation of signature whistle production by a bottlenose dolphin group two months prior to and two months following the birth of a calf to one of the social group members. We found that the production of signature whistles matching the contour belonging to our dolphin mother increased significantly in both the pre- and post-partum period. Heightened production of the mother’s signature whistle type in the first week of our focal calf’s life supports the establishment of a recognition system within this time period. Given that learning processes associated with the sound environment appear to begin shortly after calf birth, we also explored the signature whistle rates of the other social group members in an effort to determine whether any signature whistle production influenced the development of the dolphin calf’s own signature whistle type. We found that the signature whistles of the other social group members were significantly lower than production of the mother’s signature whistle until after the first week post-partum. None of the signature whistle types appeared to influence the signature whistle development of our focal calf within the scope of this study, however, as the calf did not develop a signature whistle in her first two months of life

Thunks: Evidence for Varied Harmonic Structure In an Atlantic Bottlenose Dolphin (\u3ci\u3eTursiops truncatus\u3c/i\u3e) Sound

© 2017 International Journal of Comparative Psychology. McCowan and Reiss first reported the “thunk” sound of the Atlantic bottlenose dolphin (Tursiops truncatus) during separations and discipline behavior of mother-calf dyads. This sound has been previously described as a wide-band, low frequency contact call, however the harmonic structure of this sound is more variable than previously described. Based on preliminary observations of the graded structure of thunks within our data set, we investigated the directionality of thunks with energies at higher frequencies. We recorded a bottlenose dolphin mother with her calf during the first 30-days of life, and analyzed thunk production during separation and discipline contexts. Two classifications of the thunk sound were compared to determine calf response and whether location cues were embedded in the higher harmonics of one of the thunk types. The mother oriented towards the calf significantly more during production of both thunk types during separation and discipline contexts. This sound may have potential directional information within the harmonic structure; however, we could not draw that conclusion based on our findings. Therefore, we present data here that indicates a graded structure to the harmonics of thunk sounds. McCowan and Reiss first reported the thunk sound of the Atlantic bottlenose dolphin (Tursiops truncatus) during separations and discipline behavior of mother-calf dyads. However, since this initial report, no other studies have thoroughly investigated this sound. A bottlenose dolphin mother and calf were observed during the first 30 days of life. Thunk production during separations within the mother-calf dyad and discipline behavioral events were analyzed, as thunks were predominately produced in these contexts during the original report by McCowan and Reiss. We found that variation occurs within the thunk sound, contrary to how this acoustic signal has been previously defined. We report the presence of two different types of thunks primarily present in separation events during the calf\u27s early life: the low harmonic range (LHR) and high harmonic range (HHR) thunk. LHR and HHR thunks varied in harmonic structure, but did not have significantly different peak frequencies. Furthermore, in order to determine the salience of the thunk sound to separation and discipline events, we also report on the presence of burst pulses and signature whistles when compared to thunk production. Thunks were the most produced sound during separation events, while burst pulses were more common during the mother\u27s discipline of the calf. The mother\u27s signature whistle was not as common during the course of the study, suggesting that, at least within this bottlenose dolphin mother-calf dyad, other sounds were more important for dyad communication within separation and discipline events

Thunks: Evidence for Varied Harmonic Structure in an Atlantic Bottlenose Dolphin (Tursiops truncatus) Sound

McCowan and Reiss first reported the “thunk” sound of the Atlantic bottlenose dolphin ( Tursiops truncatus ) during separations and discipline behavior of mother-calf dyads. This sound has been previously described as a wide-band, low frequency contact call, however the harmonic structure of this sound is more variable than previously described. Based on preliminary observations of the graded structure of thunks within our data set, we investigated the directionality of thunks with energies at higher frequencies. We recorded a bottlenose dolphin mother with her calf during the first 30-days of life, and analyzed thunk production during separation and discipline contexts. Two classifications of the thunk sound were compared to determine calf response and whether location cues were embedded in the higher harmonics of one of the thunk types. The mother oriented towards the calf significantly more during production of both thunk types during separation and discipline contexts. This sound may have potential directional information within the harmonic structure; however, we could not draw that conclusion based on our findings. Therefore, we present data here that indicates a graded structure to the harmonics of thunk sounds