Foraging Ecology and Maternal Transmission of Foraging Specializations of Bottlenose Dolphins (Tursiops truncatus)

Abstract

Bottlenose dolphins 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 or particular prey resources. The long duration of the mother-calf bond presents an opportunity for mothers to transmit such specializations to their calves, and cases of observational learning by dolphins are well known from captive colonies. This study explored how specializations may influence choices of habitat use and on how such specializations may spread within a community. A focal follow technique was used to document the foraging behavior of five resident females and their calves from June-August 2003 in Sarasota, FL. Females significantly differed in their selection of foraging habitats. Three of the five focal females used known foraging specializations, kerplunking and barrier feeding, and exhibited a preference for only one type. Females also increased the use of foraging habitats associated with their preferred foraging specializations. Limited observations, as well as anecdotal evidence from past studies, suggest that maternal transmission may play a role in the spread of kerplunking and barrier feeding within a community. Findings suggest that the use of foraging specializations is associated with foraging habitat preferences in Sarasota Bay as well as support the importance of incorporating knowledge of social behavior into the management structure for bottlenose dolphins. Many questions still remain concerning the prey specificity, stability, and sex-specific nature of foraging specializations and future studies should concentrate on these areas of research.