Preliminary Report of Object Carrying Behavior by Provisioned Wild Australian Humpback Dolphins (Sousa sahulensis) in Tin Can Bay, Queensland, Australia.

Object use by cetaceans has been associated with complex cognitive processes, social relations, play and tool use. A comparative approach of how cetacean species use objects will increase our understanding of this behavior. This study reports on observations of object use by a small group of provisioned wild Australian humpback dolphins (Sousa sahulensis) in Tin Can Bay, Australia. Preliminary data were collated from attendance records, interviews and photographs and classified by dolphin, object type and possible motive. Up to 29 separate occasions of object carrying behavior over seven years were documented, characteristics of which are summarized. A variety of objects biological (n = 6), artificial (n = 5) and live (n = 4) were carried or used by three male dolphins in intraspecific and interspecific interactions. Interactions were operationally defined and categorized as play (n = 4), show (n = 17), or give (n = 10). Object play was more frequent with the juvenile male. Object carrying or showing was associated with the adult males and may be related to male social behavior similar to that seen in Amazon River dolphins (Inia geoffrensis). Relinquishment of objects may be unique to interactions with people as seen during provisioning situations with bottlenose dolphins (Tursiops sp.). The behavior presented in the current study indicates further variations of object use within the species, as objects were not associated with probable foraging as has been observed elsewhere in the wild. [ABSTRACT FROM AUTHOR]