Communication, cooperation, and coordination

: how bottlenose dolphins (Tursiops truncatus) use vocal signals to coordinate a cooperative task

Abstract

A select number of species have demonstrated the recognition of their partner’s role, referred to as actively coordinated collaboration, when performing cooperative behaviour. Yet, there is a lack of data on the vocal processes underlying mechanisms of collaboration in nonhuman species. Bottlenose dolphins are known to actively coordinate cooperation with a partner and rely on vocal communication to mediate social relationships and maintain group cohesion. It was previously demonstrated that common bottlenose dolphins can use vocal signals to aid success in a cooperative button pressing task. These vocal signals include individually distinct ‘signature whistles’ that bottlenose dolphins use to broadcast their identity to group members, and a variety of other ‘variant’ (non-signature) whistles. Here, I further analysed acoustic patterns of whistle type use in this context. With acoustic data from a hydrophone array (Chapter 2), and sound-and-movement recording tags (DTAG3) attached to each dolphin (Chapter 3), I demonstrate how the vocal information shared within two dolphin dyads vary when coordinating a cooperative action i.e. in the lead up to the cooperative button press. I show that the dyads strategically use their signature whistles and specific types of variant whistles at different times during the cooperative trials. I found that the dyad can share types of variant whistles, with both individuals using the same whistle types to coordinate their behaviour. Additionally, I explore how whistle exchanges enable coordination, how the acoustic information shared by the dyad changes as task difficulty increases, and how the likelihood of the signaller producing a signature or variant whistles shifts with their behaviour. My findings provide information that enhances our understanding of bottlenose dolphin vocal communication and cooperation. This study will lead to a more comprehensive understanding of behavioural coordination and cooperation facilitated via vocal communication in the animal kingdom.

Date of Award	18 Oct 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Stephanie L King (Supervisor) & Andrew N Radford (Supervisor)