Cara Rankin, Eckerd College, Marine Science Discipline
Peter Simard, Eckerd College, Environmental Studies Discipline
Shannon Gowans, Eckerd College, Marine Science and Biology Discipline
The common bottlenose dolphin (Tursiops truncatus) utilizes vocal learning and acoustic signals within their highly social, fission-fusion lifestyle. When communicating with other individuals, they often use a distinctive vocalization unique to each individual called a signature whistle that functions in conspecific recognition. Although signature whistles are well-studied in the bottlenose dolphins of Sarasota Bay, FL, there is nothing known about signature whistles in the Tampa Bay bottlenose dolphin population. The objective of this study was to identify and categorize individual signature whistles of the free-ranging bottlenose dolphins found in Tampa Bay and thus construct a signature whistle catalog that can be utilized and added to for future studies. Acoustic recordings from 2009 to 2023 were manually analyzed using the SIGnature IDentification (SIGID) method. A total of 20 unique signature whistles were identified. Acoustic parameters of each whistle were recorded and whistles were categorized based on their contour, duration, and maximum frequency ranges. Using dorsal fin photographs taken during the acoustic recordings, the identity of individual bottlenose dolphins producing different signature whistles was investigated. In addition, the ambient noise present when the whistle was produced was measured to determine if varying ambient noise levels changed the frequency ranges of the signature whistles. This study will help us to understand the acoustic communication of this highly resident population of bottlenose dolphins, and will provide important information for conservation purposes such as anthropogenic noise mitigation strategies.
For more information: clrankin@eckerd.edu