Site Fidelity of Coastal Bottlenose Dolphins (Tursiops truncatus) off Southeast Florida, USA

Abstract

The coastal bottlenose dolphin is well studied throughout its natural range, though most research focuses on wide, well-protected habitats such as bays and estuaries rather than on narrow coastal sand banks. This study identifies a residential group of coastal bottlenose dolphins utilizing the northwestern Atlantic waters off the coast of Palm Beach County, Florida. From 2014 to 2020, 313 boat surveys were conducted, and 585 individual dolphins were identified using photo-identification. Using seasonal and annual resighting ratios, 24 dolphins were considered full-time residents, 66 dolphins were considered part-time residents, and 478 dolphins were transient. The presence of individuals with high site fidelity indicates that the region is used as a permanent habitat for some individuals, while the presence of transient animals may indicate a possible bridge between populations living to the north and south of the region.