Foraging Habitats and Associated Preferential Foraging Specializations of Bottlenose Dolphin (Tursiops truncatus) Mother-Calf Pairs

Abstract: Bottlenose dolphins (Tursiops truncatus) use a variety of foraging specializations to detect and pursue prey. Like other mammals, individual dolphins may use specialized foraging techniques that are shaped in response to habitat type or prey resources. The long duration of the mother-calf bond presents an opportunity for mothers to transmit such specializations to their calves. This study explored how the use of foraging specializations may influence selection of foraging habitats and how such specializations may spread within a dolphin community. Focal animal follows were used to document the foraging behavior of five resident females and their calves from June to August 2003 in Sarasota Bay, Florida. Sarasota Bay was classified into six habitat types based upon bathymetry and bottom topography. Individual females differed in their selection of foraging habitats. Three of the five focal females used one of two foraging specializations—kerplunking and barrier-feeding—and exhibited a preference for only one type of behavior. A significant difference in the frequency of observations of foraging specific behaviors was found between different habitat types. Limited observations, as well as anecdotal evidence from past studies, suggest that maternal transmission may play a role in the spread of foraging techniques, such as kerplunking and barrier-feeding, within the community. My findings suggest that the use of foraging specializations is associated with foraging habitat preferences in Sarasota Bay. The importance of seagrass areas to foraging dolphins and the significance of the mother-calf bond to the development of the use of foraging specializations is emphasized.

Key Words: bottlenose dolphin, Tursiops truncatus, foraging ecology, habitat use, vertical transmission, kerplunking, barrier-feeding, Sarasota Bay, Florida

Document Type: Research article

DOI: 10.1578/AM.32.1.2006.10

Page Numbers: 10-19

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