MOVEMENTS AND ACTIVITIES OF THE ATLANTIC BOTTLENOSE DOLPHIN, TURSIOPS TRUNCATUS, NEAR SARASOTA, FLORIDA

Abstract

A tagging-observation program was conducted to study the behavioral ecology of Atlantic bottlenose dolphins near Sarasota, Florida. Forty-seven bottlenose dolphins (24 males, 23 females) werecaptured. tagged, and released a total of 90 times from 29 January 1975 through 25 July 1976. Tagged animals were identified during regular boat surveys, and information was collected on all individuals and groups encountered. A total of997 tagged or marked bottlenose dolphins were sighted. A population of bottlenose dolphins was identified in an estuarine-nearshore area extending about 40 km to the south from Tampa Bay and up to 3 km into the Gulfof Mexico. Social organization was characterized by small dynamic groups that appeared to be subunits ofa larger socially interacting herd. Average group size of 688 groups was 4.8 bottlenose dolphins (standard error = 0.16), Bottlenose dolphins concentrated in different areas seasonally, possibly in response to distribution changes of important prey species. Feeding strategies of the bottlenose dolphins apparently varied according to available water depth and differed from strategies of pelagic small cetaceans. Calving apparently occurred from spring to early fall.